U.S. patent application number 15/776243 was filed with the patent office on 2019-05-23 for heating electrode device, electrical heating glass, heat-generating plate, vehicle, window for building, sheet with conductor, c.
This patent application is currently assigned to DAI NIPPON PRINTING CO., LTD.. The applicant listed for this patent is DAI NIPPON PRINTING CO., LTD.. Invention is credited to Satoshi GOISHIHARA, Manabu HIRAKAWA, Koichi KINOSHITA, Kazuo MATSUFUJI, Hidenori NAKAMURA, Hirotoshi SUETSUGU.
Application Number | 20190159296 15/776243 |
Document ID | / |
Family ID | 58718990 |
Filed Date | 2019-05-23 |
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United States Patent
Application |
20190159296 |
Kind Code |
A1 |
SUETSUGU; Hirotoshi ; et
al. |
May 23, 2019 |
HEATING ELECTRODE DEVICE, ELECTRICAL HEATING GLASS, HEAT-GENERATING
PLATE, VEHICLE, WINDOW FOR BUILDING, SHEET WITH CONDUCTOR,
CONDUCTIVE PATTERN SHEET, CONDUCTIVE HEAT-GENERATING BODY,
LAMINATED GLASS, AND MANUFACTURING METHOD FOR CONDUCTIVE
HEAT-GENERATING BODY
Abstract
A heating electrode device for energizing the heating a glass is
provided. A heating electrode device includes a plurality of
heat-generating conducting bodies extending as having a rectangular
cross section and arranged in a direction different from the
extending direction. In the cross section perpendicular to the
extending direction of the heat-generating conducting body, when it
is assumed that a thickness that is a size in a direction
perpendicular to an arrangement direction be H and a size of a
lager side of sides parallel to the arrangement direction be WB,
H/WB>1.0 is satisfied.
Inventors: |
SUETSUGU; Hirotoshi;
(Tokyo-to, JP) ; HIRAKAWA; Manabu; (Tokyo-to,
JP) ; GOISHIHARA; Satoshi; (Tokyo-to, JP) ;
NAKAMURA; Hidenori; (Tokyo-to, JP) ; MATSUFUJI;
Kazuo; (Tokyo-to, JP) ; KINOSHITA; Koichi;
(Tokyo-to, JP) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
DAI NIPPON PRINTING CO., LTD. |
Tokyo-to |
|
JP |
|
|
Assignee: |
DAI NIPPON PRINTING CO.,
LTD.
Tokyo-to
JP
|
Family ID: |
58718990 |
Appl. No.: |
15/776243 |
Filed: |
November 17, 2016 |
PCT Filed: |
November 17, 2016 |
PCT NO: |
PCT/JP2016/084086 |
371 Date: |
May 15, 2018 |
Current U.S.
Class: |
1/1 |
Current CPC
Class: |
H05B 3/84 20130101; H05B
2203/011 20130101; H05B 2203/013 20130101; Y02B 30/00 20130101;
H05B 2203/005 20130101; H05K 1/0201 20130101; H05B 2203/035
20130101; H05B 2203/017 20130101; Y02B 30/26 20130101; H02G 5/00
20130101; H05B 2203/002 20130101 |
International
Class: |
H05B 3/84 20060101
H05B003/84; H05K 1/02 20060101 H05K001/02 |
Foreign Application Data
Date |
Code |
Application Number |
Nov 17, 2015 |
JP |
2015-224986 |
Dec 4, 2015 |
JP |
2015-237841 |
Dec 7, 2015 |
JP |
2015-238751 |
Dec 16, 2015 |
JP |
2015-245413 |
Dec 16, 2015 |
JP |
2015-245419 |
Dec 21, 2015 |
JP |
2015-248646 |
Jan 8, 2016 |
JP |
2016-002857 |
Claims
1. A heating electrode device for energizing and heating glass,
comprising: a plurality of heat-generating conducting bodies
configured to extend as having a rectangular cross section and be
arranged in a direction different from the extending direction,
wherein regarding the heat-generating conducting body, when it is
assumed that a thickness which is a size in a direction
perpendicular to an arrangement direction of a cross section
perpendicular to the extending direction be H and a size of a
larger side of sides parallel to the arrangement direction be
W.sub.B, H/W.sub.B>1.0 is satisfied.
2. The heating electrode device according to claim 1, wherein in
the cross section of the heat-generating conducting body
perpendicular to the extending direction, when it is assumed that a
size of an opposite side from the side having the size of W.sub.B
be W.sub.T, W.sub.B>W.sub.T, 3 .mu.m.ltoreq.W.sub.B.ltoreq.15
.mu.m, and 1 .mu.m.ltoreq.W.sub.T.ltoreq.12 .mu.m are
satisfied.
3. The heating electrode device according to claim 1, comprising: a
transparent base material layer, wherein the heat-generating
conducting body is arranged on one surface of the base material
layer, and one surface of the heat-generating conducting body has
contact with the surface of the base material layer.
4. A heating electrode device for energizing and heating glass,
comprising: a plurality of linear heat-generating conducting
bodies, wherein regarding the heat-generating conducting body, when
it is assumed that a distance between both ends be D (mm) and a
length along the heat-generating conducting body between both ends
be L (mm), 1.02D.ltoreq.L<1.50D is satisfied.
5. The heating electrode device according to claim 4, wherein when
it is assumed that a pitch of the plurality of heat-generating
conducting bodies be P (mm), a surface area of one surface of the
heat-generating conducting body in a thickness direction per length
of 0.01 m in a plan view be S.sub.B (.mu.m.sup.2), and a surface
area of the other surface of the heat-generating conducting body
per length of 0.01 m in a plan view be S.sub.T (.mu.m.sup.2), 0.5
mm.ltoreq.P.ltoreq.5.00 mm and 0
.mu.m.sup.2<S.sub.B-S.sub.T.ltoreq.30000 .mu.m.sup.2are
satisfied.
6. The heating electrode device according to claim 5, wherein in
the cross section perpendicular to the extending direction of the
heat-generating conducting body, when it is assumed that a length
of a side on the side of S.sub.B (.mu.m.sup.2) be W.sub.B(.mu.m),
and a length of a side on the side of S.sub.T (.mu.m.sup.2) be
W.sub.T (.mu.m), W.sub.B>W.sub.T, 3
.mu.m.ltoreq.W.sub.B.ltoreq.15 .mu.m, and 1
.mu.m.ltoreq.W.sub.T.ltoreq.12 .mu.m are satisfied.
7. The heating electrode device according to claim 4, comprising: a
transparent base material layer, wherein the heat-generating
conducting body is arranged on one surface of the base material
layer, and one surface of the heat-generating conducting body has
contact with the surface of the base material layer.
8. An electrical heating glass comprising: a transparent first
panel; a transparent second panel arranged as having a gap with the
first panel; and the heating electrode device according to claim 1
arranged in the gap between the first panel and the second
panel.
9. A heat-generating plate comprising: a supporting base material;
a pair of bus bars to which a voltage is applied; and a
heat-generating conductor supported by the supporting base material
and connected to the pair of bus bars, wherein the heat-generating
conductor includes a conductive main thin wire that extends between
the pair of bus bars and includes a first large curvature portion
having a relatively large curvature and a first small curvature
portion having a relatively small curvature, and an inclination of
a cross sectional area of the first large curvature portion of a
cross sectional area of the conductive main thin wire is larger
than an inclination of a cross sectional area of the first small
curvature portion.
10. The heat-generating plate according to claim 9, wherein the
cross sectional area of the conductive main thin wire is divided by
a lower bottom having contact with the supporting base material, an
upper bottom arranged at a position facing to the lower bottom, a
first inclined portion extending between an end of the lower bottom
and an end of the upper bottom, and a second inclined portion
extending between the other end of the lower bottom and the other
end of the upper bottom, and an inclination of the cross sectional
area is expressed by each of an inclination of a straight line
passing through the end of the lower bottom and the end of the
upper bottom and an inclination of a straight line passing through
the other end of the lower bottom and the other end of the upper
bottom.
11. The heat-generating plate according to claim 10, wherein a sum
of projection sizes of the first inclined portion and the second
inclined portion on the cross sectional area of the first small
curvature portion on the supporting base material is larger than a
sum of projection sizes of the first inclined portion and the
second inclined portion on the cross sectional area of the first
large curvature portion on the supporting base material.
12. The heat-generating plate according to claim 9, wherein
projection of the cross sectional area of the first small curvature
portion on the supporting base material is larger than projection
of the cross sectional area of the first large curvature portion on
the supporting base material.
13. The heat-generating plate according to claim 10, wherein a gap
between the upper bottom and the lower bottom of the cross
sectional area of the first small curvature portion is equal to a
gap between the upper bottom and the lower bottom of the cross
sectional area of the first large curvature portion.
14. The heat-generating plate according to claim 9, wherein the
plurality of conductive main thin wires is provided, and the
heat-generating conductor further includes a conductive sub thin
wire for connecting the conductive main thin wires arranged
adjacent to each other in at least a part of the plurality of
conductive main thin wires.
15. The heat-generating plate according to claim 14, wherein the
conductive sub thin wire includes a second large curvature portion
having a relatively large curvature and a second small curvature
portion having a relatively small curvature.
16. The heat-generating plate according to claim 9, further
comprising: a covering member configured to cover the
heat-generating conductor, wherein the heat-generating conductor is
arranged between the supporting base material and the covering
member.
17. A heat-generating plate that generates heat when a voltage is
applied, comprising: a pair of glasses; a pair of bus bars to which
a voltage is applied; and a heat-generating conductor configured to
couple between the pair of bus bars, wherein the heat-generating
conductor includes a plurality of conductive thin wires that
linearly extends between the pair of bus bars and couples between
the pair of bus bars, and an average W.sub.ave of a width W of the
conductive thin wire is within a range of the following formula (a)
relative to a standard deviation .sigma. of distribution of the
width W, 0.ltoreq.4.sigma./W.sub.ave.ltoreq.0.3 Formula(a)
18. The heat-generating plate according to claim 17, wherein the
conductive thin wire includes a large curvature portion having a
relatively large curvature and a small curvature portion having a
relatively small curvature, and the width W of the conductive thin
wire is thin in the large curvature portion and thick in the small
curvature portion.
19. A heat-generating plate that generates heat when a voltage is
applied, comprising: a pair of glasses; a pair of bus bars to which
a voltage is applied; and a heat-generating conductor configured to
couple between the pair of bus bars, wherein the heat-generating
conductor includes a plurality of main conductive thin wires that
linearly extends between the pair of bus bars and couples between
the pair of bus bars and a coupling conductive thin wire for
coupling between two adjacent main conductive thin wires, and each
coupling conductive thin wire has three or more different
patterns.
20. The heat-generating plate according to claim 19, wherein the
coupling conductive thin wire is a straight line, a circular arc,
or a combination of a straight line and a circular arc.
21. The heat-generating plate according to claim 19, wherein each
coupling conductive thin wire has a pattern different from those of
all the other coupling conductive thin wires.
22. A sheet with a conductor used for a heat-generating plate that
generates heat when a voltage is applied, comprising: a base film;
a pair of bus bars to which a voltage is applied; and a
heat-generating conductor configured to couple between the pair of
bus bars, wherein the heat-generating conductor includes a
plurality of main conductive thin wires that linearly extends
between the pair of bus bars and couples between the pair of bus
bars and a coupling conductive thin wire for coupling between two
adjacent main conductive thin wires, and each coupling conductive
thin wire has three or more different patterns.
23. A conductive heat-generating body comprising: a plurality of
curved heat-generating bodies arranged separated from each other in
a first direction and extending in a second direction intersecting
with the first direction, wherein a ratio obtained by dividing a
total length of each of the plurality of curved heat-generating
bodies in the second direction by a shortest distance between both
ends of each of the plurality of curved heat-generating bodies
larger than 1.0 and equal to or less than 1.5.
24. The conductive heat-generating body according to claim 23,
wherein each of the plurality of curved heat-generating bodies is
formed by connecting a plurality of periodic curved lines having
irregular periods and amplitudes for each period along the second
direction.
25. The conductive heat-generating body according to claim 24,
wherein end positions of the plurality of curved heat-generating
bodies in the second direction are irregular.
26. The conductive heat-generating body according to claim 23,
comprising: a bypass heat-generating body configured to connect the
two adjacent curved heat-generating bodies in the first
direction.
27. The conductive heat-generating body according to claim 26,
wherein connection positions of the bypass heat-generating body are
irregular for each of the plurality of curved heat-generating
bodies.
28. The conductive heat-generating body according to claim 23,
comprising: a plurality of heat-generating body rows of which some
of heat-generating body rows are aligned in each of the first
direction and the second direction, wherein each of the plurality
of heat-generating body rows includes the plurality of curved
heat-generating bodies, and the corresponding curved
heat-generating bodies in two heat-generating body rows arranged
adjacent to each other in the second direction are connected to
each other.
29. The conductive heat-generating body according to claim 28,
wherein a shortest distance between both ends of each of the
plurality of curved heat-generating bodies included in each of the
plurality of heat-generating body rows is equal to or more than 50
mm.
30. The conductive heat-generating body according to claim 28
further comprising: a pair of bus bar electrodes arranged separated
from each other in the second direction and extending in the first
direction; and a plurality of wavy line heat-generating bodies
arranged separated from each other in the first direction and
extending in the second direction to be connected to the pair of
bus bar electrodes, wherein the plurality of wavy line
heat-generating bodies is formed by connecting the plurality of
curved heat-generating bodies included in each of the plurality of
heat-generating body rows in the second direction.
31. The conductive heat-generating body according to claim 23,
further comprising: a transparent base material layer having the
plurality of curved heat-generating bodies arranged on one
principal surface.
32. A laminated glass comprising: a pair of glass substrates
configured to be arranged to face to sandwich the conductive
heat-generating body according to claim 23.
33. A manufacturing method for a conductive heat-generating body
comprising: a step for generating a single curved heat-generating
body by connecting a plurality of periodic curved lines having
periods and amplitudes that are irregular for each period along a
second direction intersecting with a first direction; a step for
performing normalization processing for adjusting the periods of
the plurality of periodic curved lines included in the curved
heat-generating body so that a shortest distance is a first limited
value in a case where the shortest distance between both ends of
the curved heat-generating body exceeds the first limited value; a
step for generating the single curved heat-generating body again
when it is determined whether a ratio obtained by dividing a total
length of the normalized curved heat-generating body in the second
direction by the first limited value is within a range larger than
1.0 and equal to or less than 1.5 and it is determined that the
ratio is not within the range; a step for generating the plurality
of curved heat-generating bodies arranged separated from each other
in the first direction by repeating generation of the single curved
heat-generating body and the normalization processing in a position
with a predetermined interval from the normalized curved
heat-generating body when it is determined that the ratio is within
the range; a step for adjusting a phase to make the phases of the
plurality of curved heat-generating bodies in the second direction
be irregular and generating a heat-generating body row including
the plurality of curved heat-generating bodies of which a phase has
been adjusted; and a step for forming a pair of bus bar electrodes
arranged separated from each other in the second direction on a
transparent base material and extending along the first direction
and arranging the plurality of heat-generating body rows in the
first direction and the second direction between the pair of bus
bar electrodes to form a plurality of wavy line conductors
connected to the pair of bus bar electrodes and arranged separated
from each other in the first direction.
34. A heat-generating plate that generates heat when a voltage is
applied, comprising: a pair of glass plates; a conductive pattern
arranged between the pair of glass plates and defining a plurality
of opening regions; and a bonding layer arranged between the
conductive pattern and at least one of the pair of glass plates,
wherein the conductive pattern includes a plurality of connection
elements for extending between two branch points and defining the
opening region, and the connection elements for connecting the two
branch points as a straight line segment is less than 20% of the
plurality of connection elements.
35. The heat-generating plate according to claim 34, wherein an
average distance between median points of two adjacent opening
regions is equal to or more than 50 .mu.m.
36. The heat-generating plate according to claim 34, wherein a
thickness of the conductive pattern is equal to or more than 2
.mu.m.
37. The heat-generating plate according to claim 34, wherein an
average of a ratio (L.sub.1/L.sub.2) of a length L.sub.1 of each
opening region along a first direction relative to a length L.sub.2
of the opening region along a second direction perpendicular to the
first direction is equal to or more than 1.3 and equal to or less
than 1.8.
38. A conductive pattern sheet used for a heat-generating plate
that generates heat when a voltage is applied, the conductive
pattern sheet comprising: a base material; and a conductive pattern
provided on the base material and defining a plurality of opening
regions, wherein the conductive pattern includes a plurality of
connection elements extending between two branch points and
defining the opening region, and the connection elements for
connecting the two branch points as a straight line segment are
less than 20% of the plurality of connection elements.
39. A vehicle comprising: the heat-generating plate according to
claim 9.
40. A window for a building comprising: the heat-generating plate
according to claim 9.
41. An electrical heating glass comprising: a transparent first
panel; a transparent second panel arranged as having a gap with the
first panel; and the heating electrode device according to claim 4
arranged in the gap between the first panel and the second
panel.
42. A vehicle comprising: the heat-generating plate according to
claim 17.
43. A vehicle comprising: the heat-generating plate according to
claim 19.
44. A vehicle comprising: the heat-generating plate according to
claim 34.
45. A window for a building comprising: the heat-generating plate
according to claim 17.
46. A window for a building comprising: the heat-generating plate
according to claim 19.
47. A window for a building comprising: the heat-generating plate
according to claim 34.
Description
TECHNICAL FIELD
[0001] One aspect of the present invention relates to a heating
electrode device including a heat-generating conducting body that
is energized to generate heat by Joule heat and an electrical
heating glass using the same.
[0002] Another aspect of the present invention relates to a
heat-generating plate having a heat-generating conductor, and a
vehicle and a window for a building including such a
heat-generating plate.
[0003] Still another aspect of the present invention relates to a
sheet with a conductor having a heat-generating conductor, a
heat-generating plate, and a vehicle and a window for a building
including such a heat-generating plate.
[0004] Yet another aspect of the present invention relates to a
conductive heat-generating body, a laminated glass, and a
manufacturing method for a conductive heat-generating body.
[0005] Still yet another aspect of the present invention relates to
a heat-generating plate, a conductive pattern sheet, and a vehicle
and a window for a building including the heat-generating
plate.
BACKGROUND ART
[0006] Conventionally, as disclosed in JP H08-72674 A, JP
H09-207718 A, and JP 2013-56811 A, there is a technique for heating
a glass window for a vehicle such as an automobile, a railway, an
aircraft, and a ship and a glass window for a building by
energization to eliminate freezing and fogging of the glass window.
Such a glass window includes a heating electrode device between two
glass plates. The heating electrode device includes a pair of bus
bar electrodes arranged separated from each other and a plurality
linear heat-generating conducting bodies arranged to connect the
pair of bus bar electrodes, and the heat-generating conducting body
can be energized by connecting the pair of bus bar electrodes to a
power supply, and the heat-generating conducting body is heated so
as to heat the glass window.
[0007] As a heater and a defroster, a heat-generating plate
including the heat-generating conductor is used. For example, a
vehicle using a transparent heat-generating plate for a front
window (windshield) or a rear window has been known, and by heating
the heat-generating conductor, excellent visibility can be secured
by preventing frost, ice, and dew condensation on the vehicle
window.
[0008] For example, JP 2013-173402 A discloses an anti-fog window
for a vehicle in which an electric heater provided between
transparent substrates heats the entire window. In addition, JP
H08-72674 A discloses an electric heating window glass that melts
ice, frost, and prevents fog by heating a resistance heating line
provided between two plate glasses.
[0009] Conventionally, a heat-generating plate which generates heat
when a voltage is applied has been known. As a representative
application example, a transparent heat-generating plate is used as
a defroster device or a heater. The heat-generating plate as a
defroster device is used for a window glass such as a front window
(windshield) of a vehicle or a rear window. For example, in JP
H08-72674 A and JP 2013-173402 A, a heat-generating plate having a
visually transmitting performance is used as a window glass. The
heat-generating plate includes heat-generating conductors formed of
tungsten lines and the like arranged across the entire
heat-generating plate. In the heat-generating plate, by energizing
the heat-generating conductor, the heat-generating conductor is
heated by resistance heating. An increase in the temperature of a
window glass including the heat-generating plate removes fogging of
the window glass or melts snow or ice attached on the window glass,
and a visually transmitting performance through the window glass
can be secured.
[0010] Conventionally, a window glass in which the conductive
heat-generating body including a heating wire is incorporated has
been known as a defroster device used for a window glass such as a
front window or a rear window of a vehicle. In such a defroster
device, the conductive heat-generating body incorporated in the
window glass is energized to increase the temperature of the window
glass by resistance heating, and fogging of the window glass is
removed, and snow or ice attached on the window glass is melted,
and passenger's visibility can be secured.
[0011] As a material of the conductive heat-generating body,
various materials have been conventionally used. However, there is
a problem in that light beams diffracted by the conductive
heat-generating body interfere with each other and cause a beam of
light if the conductive heat-generating bodies are regularly
arranged in the window glass. A beam of light is a phenomenon in
which streaky light is visually recognized.
[0012] Furthermore, if the conductive heat-generating body is
linearly extended, external light entering the conductive
heat-generating body is reflected in the substantially same
direction, and human eyes positioned in this direction feel strong
flicker (glare).
[0013] JP 2011-210487 A discloses that the conductive
heat-generating body is formed as a wavy path and each of a
plurality of wavy lines forming each wavy path is irregularly
formed for each half period to prevent flicker.
[0014] Conventionally, as a defroster device used for a window
glass such as a front window or a rear window of a vehicle, a
window glass having heating wires formed of tungsten lines and the
like are arranged in the entire window glass has been known. In the
related art, the heating wires arranged in the entire window glass
are energized to increase the temperature of the window glass by
resistance heating, and fogging on the window glass is removed or
snow or ice attached on the window glass is melted, and the
passenger's visibility can be secured.
[0015] Recently, a defroster device in which a conductive pattern
is produced by using photolithography technique instead of the
heating wires formed of tungsten lines and the like and the
conductive pattern is energized to increase the temperature of the
window glass by resistance heating has been known (refer to JP
2011-216378 A and JP 2012-151116 A). This method has an advantage
such that a conductive pattern with a complicated shape can be
easily formed. In JP 2011-216378 A and JP 2012-151116 A, for
example, a conductive pattern having an irregular shape obtained
from the Voronoi diagram generated from sites specifically and
randomly distributed in a planer surface is formed and used as a
heating wire for increasing the temperature of the window
glass.
SUMMARY OF INVENTION
Technical Problem
[0016] As disclosed in JP H08-72674 A, JP H09-207718 A, and JP
2013-56811 A, the conventional heat-generating conducting body has
been often formed by using a tungsten wire having a circular cross
section.
[0017] Here, since the tungsten wire has a circular cross section,
it is necessary to increase a wire diameter when increasing a cross
sectional area to improve a heat generation performance (high
output). In a case of the circular cross section, the cross
sectional area is not maximized (conversely, minimized) relative to
the diameter (corresponding to cross sectional area for interfering
field of view).
[0018] As described above, conventionally, there has been a problem
in that it is necessary to increase the diameter of the circular
cross section to increase the cross sectional area of the
heat-generating conducting body and the heat-generating conducting
body is visually recognized due to an increase in the width of the
heat-generating conducting body. As a result, it is difficult to
achieve both of invisibility of the heat-generating conducting body
and improvement of a heat generation performance.
[0019] Accordingly, a first object of the present invention is to
provide a heating electrode device that efficiently increases a
cross sectional area while preventing an increase in a width of a
heat-generating conducting body and is hardly visually recognized
even with a high output. Furthermore, an electrical heating glass
having the heating electrode device is provided.
[0020] As disclosed in JP H08-72674 A, JP H09-207718 A, and JP
2013-56811 A, the heat-generating conducting body has been
conventionally formed in a wavy form. This is to prevent a beam of
light caused by a pattern of the heat-generating conducting bodies
periodically arranged at predetermined intervals.
[0021] However, the heat-generating conducting body is formed in a
wavy form, a heating value is reduced in comparison with a case
where the heat-generating conducting body is linearly formed, and
removal frost and fogging takes longer time.
[0022] Accordingly, a second object of the present invention is to
provide a heating electrode device that can reduce a time to remove
frost and fogging while preventing a beam of light. Furthermore, an
electrical heating glass having the heating electrode device is
provided.
[0023] In the heat-generating plate suitable for a heater and a
defroster, thin linear heat-generating conductors (referred to as
"conductive thin wire" below) are regularly arranged between
plates. For example, in an anti-fog window for a vehicle disclosed
in JP 2013-173402 A, a plurality of wavy conductive wires is
printed and formed in the same arrangement pattern. In addition, in
an electric heating window glass disclosed in JP H08-72674 A, a
plurality of resistance heating lines having a sinusoidal shape is
arranged in parallel.
[0024] When light emitted from a light source such as illumination
(in particular, point light source) is viewed through a transparent
heat-generating plate including a large number of conductive thin
wires, a so-called "beam of light" occurs that is emitted, around
the light source, to be observed as light extending in an elongated
radial shape from the light source toward the surroundings. The
beam of light affects the visibility. For example, when a beam of
light occurs in light observed by a driver through a vehicle
window, the beam of light may interfere the driver's visibility.
Therefore, from the viewpoint of securing excellent visibility, it
is preferable to prevent the occurrence of the beam of light as
possible.
[0025] As a result of intensive research, the inventors of the
present invention have found that a beam of light can occur due to
diffraction of light by the heat-generating conductor (conductive
thin wire) and newly found that occurrence of a beam of light can
be effectively avoided by preventing visual recognition of
diffraction light caused by the heat-generating conductor.
[0026] Furthermore, as a result of further research, the inventors
of the present invention have acquired knowledges such that it is
difficult to secure excellent visibility while preventing
occurrence of a beam of light and preventing glare that may impair
the field of view. Particularly, in a case where the
heat-generating plate is used for a window, since the
heat-generating conductor naturally exists in the field of view, it
is very difficult to achieve both to secure clear visibility and to
prevent dazzle and blur that may cause eyestrain at a high
level.
[0027] The present invention has been made in consideration of
above circumstances, and a third object of the present invention is
to provide a heat-generating plate that can secure excellent
visibility while preventing occurrence of a beam of light and a
vehicle and a window for a building including the heat-generating
plate.
[0028] In the conventional heat-generating plate, the conductive
thin wire of the heat-generating conductor linearly extends to
couple the pair of bus bars. In such a heat-generating plate, a
portion where heat cannot be generated due to disconnection of the
heat-generating conductor is made, and uneven heat generation is
caused. As a result of intensive research by the inventors of the
present invention, it has found that ease to disconnect the
conductive thin wire of the heat-generating conductor depends on
the width of the conductive thin wire. When the conductive thin
wire is arranged in a curved shape, particularly in a portion where
a curvature is large, a portion with a narrow line width is easily
disconnected by etching in a manufacturing process.
[0029] It is considered to thicken the line width of the conductive
thin wire to prevent the disconnection. However, when the line
width is thicker, the conductive thin wire is visually recognized
in an appearance of the heat-generating plate, and visibility and
design are deteriorated. Therefore, it is necessary to form the
conductive thin wire with the line width with which disconnection
hardly occurs and the conductive thin wire is not visually
recognized. The present invention has been made in consideration of
above points, and a fourth object of the present invention is to
provide a heat-generating plate with which disconnection of the
conductive thin wire of the heat-generating conductor hardly occurs
and the conductive thin wire is not visually recognized.
[0030] In the conventional heat-generating plate, the conductive
thin wire of the heat-generating conductor linearly extends to
couple the pair of bus bars. In such a heat-generating plate, a
portion where heat cannot be generated due to disconnection of the
heat-generating conductor is made, and uneven heat generation is
caused. Therefore, it has been considered to connect between
linearly extending conductive thin wires so as to maintain electric
connection even when disconnection occurs. As the easiest method,
to connect between the linearly extending conductive thin wires
with a linear bridge is considered. However, in this case, an
orientation direction of the bridge is conspicuous when an entire
heat-generating plate is observed, and streaky light referred to as
a beam of light occurs. Therefore, visibility through the
heat-generating plate is deteriorated.
[0031] The present invention has been made in consideration of
above points, and a fifth object is to provide a heat-generating
plate that does not easily cause uneven heat generation even when
the heat-generating conductor is disconnected and does not
deteriorate visibility.
[0032] Furthermore, with a conductive film having a wavy path
disclosed in JP 2011-210487 A, glare may be certainly reduced.
However, since the shapes of the wavy paths are irregularly formed,
there are a portion with a high temperature and a portion with a
low temperature, and uneven heat may be caused. Therefore, for
example, when the conductive film disclosed in JP 2011-210487 A is
incorporated in a window glass of a vehicle, a place where fogging
is removed and a place where fogging is not removed, or a place
where snow or ice is melted or a place where snow or ice is not
melted are made in the window glass, and there is a possibility
that passenger's visibility cannot be satisfactorily secured.
[0033] The present invention has been made to solve the above
problems, and a sixth object of the present invention is to provide
a conductive heat-generating body and a laminated glass capable of
preventing uneven heat while preventing a beam of light and flicker
and a manufacturing method therefor.
[0034] FIG. 92 illustrates a partially enlarged conductive pattern
840 in a conventional defroster device disclosed in JP 2011-216378
A and JP 2012-151116 A. In the conventional defroster device, the
conductive pattern 840 includes a plurality of connection elements
844 extending between two branch points 842 and defining an opening
region 843, and each connection element 844 is formed of a single
straight line segment. As a result of intensive research on the
defroster device including such a connection element 844 by the
inventors of the present invention, it has been found that an
observer (for example, passenger such as driver) can visually
recognize the conductive pattern 840 including the connection
elements 844 depending on the shape of each connection element 844
formed of a single straight line segment. When light such as
external light entering the defroster device enters a side surface
formed by a flat surface of the connection element 844, the light
that has entered each position on the side surface is reflected by
the side surface in a substantially constant direction. Then, the
reflected light is visually recognized by the observer so that the
conductive pattern 840 including the connection elements 844 is
visually recognized by the observer. The visual recognition of the
conductive pattern 840 including the connection elements 844 by the
observer such as a driver deteriorates visibility of the observer
through the window glass.
[0035] The present invention has been made in consideration of
these points, and a seventh object of the present invention is to
improve invisibility of a conductive pattern of a defroster
device.
Solution to Problem
[0036] The present invention will be described below. Here, for
easy understanding, reference numerals in the drawings are
attached. However, the present invention is not limited to
this.
[0037] [First Invention]
[0038] One aspect of the present invention is a heating electrode
device, for energizing and heating glass, that includes a plurality
of heat-generating conducting bodies configured to extend as having
a rectangular cross section and arranged in a direction different
from the extending direction, in which regarding the
heat-generating conducting body, when it is assumed that a
thickness which is a size in a direction perpendicular to an
arrangement direction of a cross section perpendicular to the
extending direction be H and a size of a larger side of sides
parallel to the arrangement direction be W.sub.B, H/W.sub.B>1.0
is satisfied, and the problems are solved by the heating electrode
device.
[0039] Another aspect of the present invention is the heating
electrode device in which, in the cross section of the
heat-generating conducting body perpendicular to the extending
direction, when it is assumed that a size of an opposite side from
the side having the size of W.sub.B be W.sub.T, W.sub.B>W.sub.T,
3 .mu.m.ltoreq.W.sub.B.ltoreq.15 .mu.m, and 1
.mu.m.ltoreq.W.sub.T.ltoreq.12 .mu.m are satisfied.
[0040] Still another aspect of the present invention is any one of
the heating electrode devices that includes a transparent base
material layer and in which the heat-generating conducting body is
arranged on one surface of the base material layer, and one surface
of the heat-generating conducting body has contact with the surface
of the base material layer.
[0041] Still another aspect of the present invention is an
electrical heating glass including a transparent first panel, a
transparent second panel arranged as having a gap with the first
panel, and any one of the heating electrode devices arranged in the
gap between the first panel and the second panel.
[0042] According to each aspect of the present invention, in the
heating electrode device and the electrical heating glass using the
same, the cross sectional area is efficiently increased while
preventing an increase in a width of the heat-generating conducting
body, and the heat-generating conducting body can be hardly
visually recognized while obtaining a high output. The function can
be enhanced.
[0043] [Second Invention]
[0044] Another aspect of the present invention is a heating
electrode device for energizing and heating glass that includes a
plurality of linear heat-generating conducting bodies and in which,
regarding the heat-generating conducting body, when it is assumed
that a distance between both ends be D (mm) and a length along the
heat-generating conducting body between both ends be L (mm),
1.02D.ltoreq.L<1.50D is satisfied, and the heating electrode
device solves the above problems.
[0045] Still another aspect of the present invention is the heating
electrode device in which when it is assumed that a pitch of the
plurality of heat-generating conducting bodies be P (mm), a surface
area of one surface of the heat-generating conducting body in a
thickness direction per length of 0.01 m in a plan view be S.sub.B
(.mu.m.sup.2), and a surface area of the other surface per length
of 0.01 m in a plan view be S.sub.T (.mu.m.sup.2), 0.5
mm.ltoreq.P.ltoreq.5.00 mm and 0
.mu.m.sup.2<S.sub.B-S.sub.T.ltoreq.30000 .mu.m.sup.2 are
satisfied.
[0046] Yet another aspect of the present invention is the heating
electrode device in which, in the cross section perpendicular to
the extending direction of the heat-generating conducting body,
when it is assumed that a length of a side on the side of S.sub.B
(.mu.m.sup.2) be W.sub.B (.mu.m), and a length of a side on the
side of S.sub.T (.mu.m.sup.2) be W.sub.T (.mu.m),
W.sub.B>W.sub.T, 3 .mu.m.ltoreq.W.sub.B.ltoreq.15 .mu.m, and 1
.mu.m.ltoreq.W.sub.T.ltoreq.12 .mu.m are satisfied.
[0047] Still yet another aspect of the present invention is any one
of the heating electrode devices that includes a transparent base
material layer and in which the heat-generating conducting body is
arranged on one surface of the base material layer, and one surface
of the heat-generating conducting body has contact with the surface
of the base material layer.
[0048] Still another aspect of the present invention is an
electrical heating glass including a transparent first panel, a
transparent second panel arranged as having a gap with the first
panel, and any one of the heating electrode devices arranged in the
gap between the first panel and the second panel.
[0049] According to each aspect of the present invention, in the
heating electrode device and the electrical heating glass using the
same, a heating value can be satisfactorily secured while
preventing a beam of light, and fogging and frost can be smoothly
eliminated.
[0050] [Third Invention]
[0051] Another aspect of the present invention relates to a
heat-generating plate that includes a supporting base material, a
pair of bus bars to which a voltage is applied, and a
heat-generating conductor supported by the supporting base material
and connected to the pair of bus bars, in which the heat-generating
conductor includes a conductive main thin wire that extends between
the pair of bus bars and includes a first large curvature portion
having a relatively large curvature and a first small curvature
portion having a relatively small curvature, and an inclination of
a cross sectional area of the first large curvature portion of the
conductive main thin wire is larger than an inclination of the
cross sectional area of the first small curvature portion.
[0052] According to the present aspect, even when the
heat-generating conductor includes the conductive main thin wire,
both of prevention of occurrence of a beam of light and antiglare
can be achieved at a high level.
[0053] It is preferable that the cross sectional area of the
conductive main thin wire be divided by a lower bottom having
contact with the supporting base material, an upper bottom arranged
at a position facing to the lower bottom, a first inclined portion
extending between an end of the lower bottom and an end of the
upper bottom, and a second inclined portion extending between the
other end of the lower bottom and the other end of the upper
bottom, and an inclination of the cross sectional area be expressed
by each of an inclination of a straight line passing through the
end of the lower bottom and the end of the upper bottom, and an
inclination of a straight line passing through the other end of the
lower bottom and the other end of the upper bottom.
[0054] According to the present aspect, the inclination of the
cross sectional area of the conductive main thin wire is
appropriately expressed.
[0055] A sum of projection sizes of the first inclined portion and
the second inclined portion of the cross sectional area of the
first small curvature portion on the supporting base material may
be larger than a sum of projection sizes of the first inclined
portion and the second inclined portion of the cross sectional area
of the first large curvature portion on the supporting base
material.
[0056] According to the present aspect, the sizes of the first
inclined portion and the second inclined portion in the conductive
main thin wire which easily contribute to generate glare by light
reflection can be changed between the first large curvature portion
and the first small curvature portion, and it is possible to
prevent the glare from being emphasized by light reflection.
[0057] Projection of the cross sectional area of the first small
curvature portion on the supporting base material may be larger
than projection of the cross sectional area of the first large
curvature portion on the supporting base material.
[0058] According to the present aspect, the size of the portion in
the conductive main thin wire that can contribute to the reflection
of light can be changed between the first large curvature portion
and the first small curvature portion, and it is possible to
prevent the glare such as dazzle and blur from being emphasized by
light reflection.
[0059] A gap between the upper bottom and the lower bottom of the
cross sectional area of the first small curvature portion may be
equal to a gap between the upper bottom and the lower bottom of the
cross sectional area of the first large curvature portion.
[0060] According to the present aspect, good workability of the
heat-generating conductor is secured, and the first large curvature
portion and the first small curvature portion can be easily
formed.
[0061] The plurality of conductive main thin wires is provided, and
the heat-generating conductor may further include a conductive sub
thin wire for coupling the conductive main thin wires arranged
adjacent to each other in at least a part of the plurality of
conductive main thin wires.
[0062] According to the present aspect, since the conductive main
thin wires are connected to each other with the conductive sub thin
wire, even when a part of the conductive main thin wire is
disconnected, electric power can be supplied from the other
conductive main thin wire to the disconnected conductive main thin
wire via the conductive sub thin wire. Therefore, uneven heat
generation can be effectively reduced.
[0063] The conductive sub thin wire may include a second large
curvature portion having a relatively large curvature and a second
small curvature portion having a relatively small curvature.
[0064] According to the present aspect, the conductive sub thin
wire is arranged in a curved shape, and a visible beam of light
which can be effectively prevented.
[0065] The heat-generating plate may further include a covering
member for covering the heat-generating conductor, and the
heat-generating conductor may be arranged between the supporting
base material and the covering member.
[0066] According to the present aspect, it is possible to provide
the heat-generating plate in which the heat-generating conductor is
arranged between the supporting base material and the covering
member, and the heat-generating plate can be easily applied to
various windows.
[0067] Another aspect of the present invention relates to a vehicle
including the heat-generating plate.
[0068] Another aspect of the present invention relates to a window
for a building including the heat-generating plate.
[0069] According to each aspect of the present invention, since the
inclination of the cross sectional area of the "first large
curvature portion having a relatively large curvature" of the cross
sectional area of the conductive main thin wire of the
heat-generating conductor is larger than the inclination of the
cross sectional area of the "first small curvature portion having a
relatively small curvature", both of prevention of occurrence of a
beam of light and antiglare can be achieved at a high level.
[0070] [Fourth Invention]
[0071] A heat-generating plate according to another aspect of the
present invention, which generates heat when a voltage is applied,
includes a pair of glasses, a pair of bus bars to which a voltage
is applied, and a heat-generating conductor that couples between
the pair of bus bars, in which the heat-generating conductor
includes a plurality of conductive thin wires that linearly extends
between the pair of bus bars and couples between the pair of bus
bars, and an average W.sub.ave width W of of the conductive thin
wire is within a range of the following formula (a) relative to a
standard deviation a of distribution of the width W.
0.ltoreq.4.sigma./W.sub.ave.ltoreq.0.3 Formula (a)
[0072] In the heat-generating plate according to another aspect of
the present invention, the conductive thin wire includes a large
curvature portion having a relatively large curvature and a small
curvature portion having a relatively small curvature, and the
width W of the conductive thin wire may be thin in the large
curvature portion and may be thick in the small curvature
portion.
[0073] A vehicle according to another aspect of the present
invention includes any one of the heat-generating plates according
to the present invention.
[0074] A window for a building according to another aspect of the
present invention includes any one of the heat-generating plates
according to the present invention.
[0075] According to each aspect of the present invention, the
conductive thin wire of the heat-generating conductor of the
heat-generating plate can be hardly disconnected.
[0076] [Fifth Invention]
[0077] A heat-generating plate according to another aspect of the
present invention is a heat-generating plate, which generates heat
when a voltage is applied, includes a pair of glasses, a pair of
bus bars to which a voltage is applied, and a heat-generating
conductor that couples between the pair of bus bars, in which the
heat-generating conductor includes a plurality of conductive thin
wires that linearly extends between the pair of bus bars and
couples between the pair of bus bars and a coupling conductive thin
wire for coupling between two adjacent main conductive thin wires,
and each coupling conductive thin wire has three or more different
patterns.
[0078] In the heat-generating plate according to another aspect of
the present invention, the pattern of the coupling conductive thin
wire may be a straight line, a circular arc, or a combination of a
straight line and a circular arc.
[0079] In the heat-generating plate according to another aspect of
the present invention, each coupling conductive thin wire may have
a pattern different from those of all the other coupling conductive
thin wires.
[0080] A vehicle according to another aspect of the present
invention includes any one of the heat-generating plates according
to the present invention.
[0081] A window for a building according to another aspect of the
present invention includes any one of the heat-generating plates
according to the present invention.
[0082] A sheet with a conductor according to another aspect of the
present invention is a sheet with a conductor, which is used for a
heat-generating plate that generates heat when a voltage is
applied, includes a base film, a pair of bus bars to which a
voltage is applied, and a heat-generating conductor that couples
between the pair of bus bars, in which the heat-generating
conductor includes a plurality of conductive thin wires that
linearly extends between the pair of bus bars and couples between
the pair of bus bars and a coupling conductive thin wire for
coupling between two adjacent main conductive thin wires, and each
coupling conductive thin wire has three or more different
patterns.
[0083] According to each aspect of the present invention, even when
the heat-generating conductor of the heat-generating plate is
disconnected, uneven heat generation hardly occurs, and it is
possible to prevent deterioration in visibility.
[0084] [Sixth Invention]
[0085] To solve the above problems, in another aspect of the
present invention, a conductive heat-generating body is provided
which includes a plurality of curved heat-generating bodies
arranged separated from each other in a first direction and
extending in a second direction intersecting with the first
direction, in which a ratio of an entire length of each of the
plurality of curved heat-generating bodies in the second direction
divided by a shortest distance between both ends of each of the
plurality of curved heat-generating bodies is larger than 1.0 and
equal to or less than 1.5.
[0086] Each of the plurality of curved heat-generating bodies may
be formed by connecting a plurality of periodic curved lines having
irregular periods and amplitudes for each period along the second
direction.
[0087] End positions of ends of the plurality of curved
heat-generating bodies in the second direction may be
irregular.
[0088] A bypass heat-generating body that connects the two adjacent
curved heat-generating bodies in the first direction may be
included.
[0089] Connection positions of the bypass heat-generating body may
be irregular for each of the plurality of curved heat-generating
bodies.
[0090] A plurality of heat-generating body rows of which some of
heat-generating body rows are aligned in each of the first
direction and the second direction may be included, each of the
plurality of heat-generating body rows may include the plurality of
curved heat-generating bodies, and the corresponding curved
heat-generating bodies in two heat-generating body rows arranged
adjacent to each other in the second direction may be connected to
each other.
[0091] A shortest distance between both ends of each of the
plurality of curved heat-generating bodies included in each of the
plurality of heat-generating body rows may be equal to or more than
50 mm.
[0092] A pair of bus bar electrodes arranged separated from each
other in the second direction and extending in the first direction
and a plurality of wavy line heat-generating bodies arranged
separated from each other in the first direction and extending in
the second direction to be connected to the pair of bus bar
electrodes may be included, and the plurality of wavy line
heat-generating bodies may be formed by connecting the plurality of
curved heat-generating bodies included in each of the plurality of
heat-generating body rows in the second direction.
[0093] A transparent base material layer in which the plurality of
curved heat-generating bodies is arranged on one principal surface
may be included.
[0094] A laminated glass may be used which includes a pair of glass
substrates arranged to face to each other so as to sandwich the
conductive heat-generating body.
[0095] In another aspect of the present invention, a manufacturing
method for a conductive heat-generating body is provided that
includes a step for generating a single curved heat-generating body
by connecting a plurality of periodic curved lines having periods
and amplitudes that are irregular for each period along a second
direction intersecting with a first direction, a step for
performing normalization processing for adjusting the periods of
the plurality of periodic curved lines included in the curved
heat-generating body so that a shortest distance is a first limited
value in a case where the shortest distance between both ends of
the curved heat-generating body exceeds the first limited value, a
step for generating the single curved heat-generating body again
when it is determined whether a ratio obtained by dividing an
entire length of the normalized curved heat-generating body in the
second direction by the first limited value is within a range
larger than 1.0 and equal to or less than 1.5 and it is determined
that the ratio is not within the range, a step for generating the
plurality of curved heat-generating bodies arranged separated from
each other in the first direction by repeating generation of the
single curved heat-generating body and the normalization processing
in a position with a predetermined interval from the normalized
curved heat-generating body when it is determined that the ratio is
within the range, a step for adjusting a phase to make the phases
of the plurality of curved heat-generating bodies in the second
direction be irregular and generating a heat-generating body row
including the plurality of curved heat-generating bodies of which a
phase has been adjusted, and a step for forming a pair of bus bar
electrodes arranged separated from each other in the second
direction on a transparent base material and extending along the
first direction and arranging the plurality of heat-generating body
rows in the first direction and the second direction between the
pair of bus bar electrodes to form a plurality of wavy line
conductors connected to the pair of bus bar electrodes and arranged
separated from each other in the first direction.
[0096] According to each aspect of the present invention, uneven
heat can be prevented while preventing a beam of light and
flicker.
[0097] [Seventh Invention]
[0098] A heat-generating plate according to another aspect of the
present invention includes a pair of glass plates, a conductive
pattern arranged between the pair of glass plates and defining a
plurality of opening regions, and a bonding layer arranged between
the conductive pattern and at least one of the pair of glass
plates, in which the conductive pattern includes a plurality of
connection elements for extending between two branch points and
defining the opening region, and the connection elements for
connecting the two branch points as a straight line segment are
less than 20% of the plurality of connection elements.
[0099] In the heat-generating plate according to the aspect of the
present invention, an average distance between median points of the
two adjacent opening regions may be equal to or more than 50
.mu.m.
[0100] In the heat-generating plate according to the aspect of the
present invention, the thickness of the conductive pattern may be
equal to or more than 2 .mu.m.
[0101] In the heat-generating plate according to the aspect of the
present invention, an average of a ratio (L.sub.1/L.sub.2) of a
length L.sub.1 of each opening region along the first direction
relative to a length L.sub.2 of the opening region along the second
direction perpendicular to the first direction may be equal to or
more than 1.3 and equal to or less than 1.8.
[0102] A conductive pattern sheet according to another aspect of
the present invention includes a base material and a conductive
pattern provided on the base material and defining a plurality of
opening regions, in which the conductive pattern includes a
plurality of connection elements extending between two branch
points and defining the opening region, and the connection elements
for connecting the two branch points as a straight line segment are
less than 20% of the plurality of connection elements.
[0103] A vehicle according to another aspect of the present
invention includes the heat-generating plate described above.
[0104] A window for a building according to another aspect of the
present invention includes the heat-generating plate described
above.
[0105] According to each aspect of the present invention,
invisibility of the conductive pattern of the defroster device can
be improved.
BRIEF DESCRIPTION OF DRAWINGS
[0106] FIG. 1(a) is a plan view for explaining an electrical
heating glass according to one embodiment, FIG. 1(b) is an enlarged
view of a heat-generating conducting body which is one example of a
heat-generating conducting body, and FIG. 1(c) is an enlarged view
of a heat-generating conducting body which is another example of
the heat-generating conducting body.
[0107] FIG. 2 is a cross-sectional view for explaining a layer
structure of the electrical heating glass.
[0108] FIG. 3 is a perspective view for explaining a heating
electrode device.
[0109] FIG. 4 is a view for explaining a form of the
heat-generating conducting body.
[0110] FIGS. 5(a) to 5(d) are diagrams for explaining a method for
producing the electrical heating glass.
[0111] FIG. 6(a) is a plan view for explaining an electrical
heating glass according to one embodiment, and FIG. 6(b) is an
enlarged view of a heat-generating conducting body which is one
example of a heat-generating conducting body.
[0112] FIG. 7 is a cross-sectional view for explaining a layer
structure of the electrical heating glass.
[0113] FIG. 8 is a perspective view for explaining the heating
electrode device.
[0114] FIG. 9 is a view for explaining a form of the
heat-generating conducting body.
[0115] FIGS. 10(a) to 10(d) are diagrams for explaining a method
for producing the electrical heating glass.
[0116] FIG. 11A is a diagram for explaining a relationship between
a cross sectional shape of a thin linear heat-generating conductor
and a light reflection aspect and indicates an example of the
heat-generating conductor having a rectangular cross section.
[0117] FIG. 11B is a diagram for explaining a relationship between
a cross sectional shape of a thin linear heat-generating conductor
and a light reflection aspect and indicates an example of the
heat-generating conductor having a non-rectangular cross
section.
[0118] FIG. 12 is a perspective view for schematically illustrating
an automobile (vehicle) on which a battery (power supply) is
mounted.
[0119] FIG. 13 is a front view of a front window including a
transparent heat-generating plate.
[0120] FIG. 14 is a cross-sectional view of the heat-generating
plate (front window) taking along a line XIV-XIV illustrated in
FIG. 13.
[0121] FIG. 15 is an enlarged plan view illustrating an exemplary
wiring pattern of the heat-generating conductor.
[0122] FIG. 16A is an enlarged view of a portion (first small
curvature portion) indicated by a reference numeral "31a" in FIG.
15.
[0123] FIG. 16B is an enlarged view of a portion (first large
curvature portion) indicated by a reference numeral "31b" in FIG.
15.
[0124] FIG. 17A is a cross-sectional view taken along a line
XVIIA-XVIIA in FIG. 16A.
[0125] FIG. 17B is a cross-sectional view along a line XVIIB-XVIIB
in FIG. 16B.
[0126] FIG. 18 is a cross-sectional view illustrating a
modification of the heat-generating plate.
[0127] FIG. 19 is a cross-sectional view illustrating one process
of a manufacturing method for the heat-generating plate.
[0128] FIG. 20 is a cross-sectional view illustrating one process
of the manufacturing method for the heat-generating plate.
[0129] FIG. 21 is a cross-sectional view illustrating one process
of the manufacturing method for the heat-generating plate.
[0130] FIG. 22 is a cross-sectional view illustrating one process
of the manufacturing method for the heat-generating plate.
[0131] FIG. 23 is a cross-sectional view illustrating one process
of the manufacturing method for the heat-generating plate.
[0132] FIG. 24 is a cross-sectional view illustrating one process
of the manufacturing method for the heat-generating plate.
[0133] FIG. 25 is a cross-sectional view illustrating one process
of the manufacturing method for the heat-generating plate.
[0134] FIG. 26 is a cross-sectional view illustrating another
modification of the heat-generating plate.
[0135] FIG. 27 is a cross-sectional view illustrating still another
modification of the heat-generating plate.
[0136] FIG. 28 is a cross-sectional view illustrating yet another
modification of the heat-generating plate.
[0137] FIG. 29 is a view for explaining an embodiment according to
the present invention and is a perspective view schematically
illustrating a vehicle including a heat-generating plate.
Particularly, in FIG. 29, an automobile including a front window
configured by the heat-generating plate is schematically
illustrated as an example of the vehicle.
[0138] FIG. 30 is a view illustrating the heat-generating plate
from a normal direction of a plate surface.
[0139] FIG. 31 is a cross-sectional view of the heat-generating
plate taken along a line XXXI-XXXI in FIG. 30.
[0140] FIG. 32 is a plan view illustrating a sheet with a conductor
from a normal direction of a sheet surface and is a plan view of an
example of the sheet with a conductor.
[0141] FIG. 33 is a plan view in which a part of a conductive thin
wire is enlarged and illustrated.
[0142] FIG. 34 is an enlarged cross-sectional view of the sheet
with a conductor.
[0143] FIG. 35 is a view for explaining an example of a
manufacturing method for a heat-generating plate.
[0144] FIG. 36 is a view for explaining an example of the
manufacturing method for the heat-generating plate.
[0145] FIG. 37 is a view for explaining an example of the
manufacturing method for the heat-generating plate.
[0146] FIG. 38 is a view for explaining an example of the
manufacturing method for the heat-generating plate.
[0147] FIG. 39 is a view for explaining an example of the
manufacturing method for the heat-generating plate.
[0148] FIG. 40 is a view for explaining an example of the
manufacturing method for the heat-generating plate.
[0149] FIG. 41 is a view for explaining an example of the
manufacturing method for the heat-generating plate.
[0150] FIG. 42 is a view for explaining an example of the
manufacturing method for the heat-generating plate.
[0151] FIG. 43 is a view for explaining an example of the
manufacturing method for the heat-generating plate.
[0152] FIG. 44 is a view for explaining an embodiment according to
the present invention and is a perspective view schematically
illustrating a vehicle including a heat-generating plate.
Particularly, in FIG. 44, an automobile including a front window
configured by the heat-generating plate is schematically
illustrated as an example of the vehicle.
[0153] FIG. 45 is a view illustrating the heat-generating plate
from a normal direction of a plate surface.
[0154] FIG. 46 is a cross-sectional view of the heat-generating
plate taken along a line XLVI-XLVI in FIG. 44.
[0155] FIG. 47 is a plan view illustrating a sheet with a conductor
from a normal direction of a sheet surface and is a plan view of an
example of the sheet with a conductor.
[0156] FIG. 48 is a view for explaining an example of a
manufacturing method for the heat-generating plate.
[0157] FIG. 49 is a view for explaining an example of the
manufacturing method for the heat-generating plate.
[0158] FIG. 50 is a view for explaining an example of the
manufacturing method for the heat-generating plate.
[0159] FIG. 51 is a view for explaining an example of the
manufacturing method for the heat-generating plate.
[0160] FIG. 52 is a view for explaining an example of the
manufacturing method for the heat-generating plate.
[0161] FIG. 53 is a view for explaining an example of the
manufacturing method for the heat-generating plate.
[0162] FIG. 54 is a view for explaining an example of the
manufacturing method for the heat-generating plate.
[0163] FIG. 55 is a plan view of a conductive heat-generating body
according to an embodiment of the present invention.
[0164] FIG. 56 is a diagram of a plurality of heat-generating body
rows arranged along a vertical direction and a horizontal
direction.
[0165] FIG. 57 is a block diagram illustrating a schematic
configuration of a heat-generating body generating device that
automatically generates a plurality of curved heat-generating
bodies included in the heat-generating body row.
[0166] FIG. 58 is a flowchart illustrating an example of a
processing procedure of the heat-generating body generating device
in FIG. 57.
[0167] FIG. 59 is a plan view of a conductive heat-generating body
having bypass heat-generating bodies.
[0168] FIG. 60 is a view illustrating an example in which a
conductive heat-generating body is incorporated in a front window
of a car.
[0169] FIG. 61 is a diagram in which two bus bar electrodes are
arranged along sides on both ends of the front window in a
short-side direction and a plurality of wavy line conductors is
arranged along a longitudinal direction of the front window.
[0170] FIG. 62 is a perspective view of a vehicle.
[0171] FIG. 63 is a cross-sectional view taken along a line
LXIII-LXIII in FIG. 60 of the front window.
[0172] FIGS. 64(a) to 64(e) are cross-sectional views illustrating
a process for manufacturing a conductive heat-generating body.
[0173] FIG. 65 is a cross-sectional view of a heating element
sheet.
[0174] FIG. 66 is a cross-sectional view illustrating an example of
a process for manufacturing a laminated glass using the heating
element sheet in FIG. 65.
[0175] FIG. 67 is a cross-sectional view of the manufacturing
process subsequent to FIG. 66.
[0176] FIG. 68 is a cross-sectional view of the manufacturing
process subsequent to FIG. 67.
[0177] FIG. 69 is a cross-sectional view of a laminated glass in a
case where a peeling layer remains.
[0178] FIG. 70 is a view for explaining an embodiment according to
the present invention and is a perspective view schematically
illustrating a vehicle including a heat-generating plate.
Particularly, in FIG. 70, an automobile including a heat-generating
plate is schematically illustrated as an example of the
vehicle.
[0179] FIG. 71 is a view illustrating the heat-generating plate as
viewed from a normal direction of a plate surface.
[0180] FIG. 72 is a cross-sectional view of the heat-generating
plate in FIG. 71.
[0181] FIG. 73 is a plan view of an exemplary shape of a reference
pattern to be referred to determine a conductive pattern of the
heat-generating plate.
[0182] FIG. 74 is an enlarged view of a part of the conductive
pattern with the reference pattern illustrated in FIG. 73.
[0183] FIG. 75 is a view for explaining an action of the conductive
pattern.
[0184] FIG. 76 is a view for explaining an example of a
manufacturing method for the heat-generating plate.
[0185] FIG. 77 is a view for explaining an example of the
manufacturing method for the heat-generating plate.
[0186] FIG. 78 is a view for explaining an example of the
manufacturing method for the heat-generating plate.
[0187] FIG. 79 is a view for explaining an example of the
manufacturing method for the heat-generating plate.
[0188] FIG. 80 is a view for explaining an example of the
manufacturing method for the heat-generating plate.
[0189] FIG. 81 is a view for explaining an example of the
manufacturing method for the heat-generating plate.
[0190] FIG. 82 is a view for explaining an example of the
manufacturing method for the heat-generating plate.
[0191] FIG. 83 is a view for explaining a modification of the
manufacturing method for the heat-generating plate.
[0192] FIG. 84 is a view for explaining the modification of the
manufacturing method for the heat-generating plate.
[0193] FIG. 85 is a view for explaining the modification of the
manufacturing method for the heat-generating plate.
[0194] FIG. 86 is a view for explaining the modification of the
manufacturing method for the heat-generating plate.
[0195] FIG. 87 is a view for explaining the modification of the
manufacturing method for the heat-generating plate.
[0196] FIG. 88 is a view for explaining another modification of the
manufacturing method for the heat-generating plate.
[0197] FIG. 89 is a view for explaining another modification of the
manufacturing method for the heat-generating plate.
[0198] FIG. 90 is a plan view illustrating a modification of the
reference pattern.
[0199] FIG. 91 is an enlarged view of a part of the conductive
pattern with the reference pattern illustrated in FIG. 90.
[0200] FIG. 92 is a diagram for explaining the related art.
DESCRIPTION OF EMBODIMENTS
[0201] The actions and advantages of the present invention
described above will be clarified from the following embodiments.
The present invention will be described based on the forms
illustrated in the drawings. However, the present invention is not
limited to these embodiments. It should be noted that the size and
the shape of each member in the drawings may be exaggerated or
deformed for easy understanding.
First Embodiment
[0202] FIG. 1(a) is a view for explaining one embodiment and is a
conceptual view of an electrical heating glass 10 in a plan view.
FIG. 1(b) is an enlarged view of a portion indicated by Ia in FIG.
1(a), and an enlarged view of a heat-generating conducting body 22L
which is an example of a heat-generating conducting body 22 is
illustrated. FIG. 1(c) is an enlarged view of a portion indicated
by Ia in FIG. 1(a), and an enlarged view of a heat-generating
conducting body 22M which is another example of the heat-generating
conducting body 22 is illustrated. FIG. 2 is a cross-sectional view
taken along a line II-II illustrated in FIG. 1 and is a view for
explaining a layer structure along a thickness direction of the
electrical heating glass 10. Such an electrical heating glass 10
is, for example, included in an automobile as a windshield of an
automobile. In addition, the electrical heating glass 10 can be
used as a window in a place having a so-called glass window, for
example, a window of a vehicle such as a train, an aircraft, and a
ship, including the automobile, and a window of a building.
[0203] As can be found from FIGS. 1 and 2, the electrical heating
glass 10 has a plate-like shape as a whole, and a plurality of
layers is laminated along the thickness direction (Z-axis direction
in FIGS. 1 and 2). More specifically, as illustrated in the
cross-sectional view in FIG. 2, the electrical heating glass 10
according to the present embodiment includes a first panel 11, an
adhesive layer 12, a heating electrode device 20, an adhesive layer
14, and a second panel 15. Each component will be described
below.
[0204] The first panel 11 and the second panel 15 are plate-like
members having translucency, that is, transparent plate-like
members and are arranged substantially in parallel to each other
with an interval between plate surfaces arranged to face to each
other. The electrical heating glass 10 has a so-called double panel
structure. Here, the plate surface indicates two planes that are
parallel to the XY plane and face to each other among the surfaces
of the first panel 11 and the second panel 15 in FIG. 2. A base
material layer 24 and the heating electrode device 20 are partially
arranged between the first panel 11 and the second panel 15, and
the base material layer 24 and the heating electrode device 20 are
integrated with the adhesive layers 12 and 14. The first panel 11
and the second panel 15 can be formed of a plate glass. For these
panels, the same plate glass can be used as that used for a window
normally provided in a facility (for example, vehicle and building)
to which the electrical heating glass 10 is applied. For example,
sheet glass, float plate glass, reinforced plate glass, partial
plate glass, and the like made of soda-lime glass (blue plate
glass), borosilicate glass (white plate glass), quartz glass, soda
glass, and potassium glass can be exemplified. In addition, the
panels may have a three-dimensionally curved bent portion as
necessary. However, the panel is not necessarily formed of a glass
plate, and may be a resin plate made of a resin such as an acrylic
resin or a polycarbonate resin. However, from the viewpoint of
weather resistance property, heat resistance property,
transparence, and the like, it is preferable that the plate be a
plate glass. Although thicknesses of the first panel 11 and the
second panel 15 are not particularly limited, the thicknesses are
equal to or more than 1.5 mm and equal to or less than 5 mm in
general.
[0205] The adhesive layer 12 is a layer formed of an adhesive
laminated on the surface of the first panel 11 on the side of the
second panel 15 and bonds the base material layer 24 to the first
panel 11. Although the adhesive is not particularly limited, a
polyvinyl butyral resin can be used from the viewpoint of
adhesiveness, weather resistance property, heat resistance
property, and the like. Although the thickness of the adhesive
layer 12 is not particularly limited, the thickness is equal to or
more than 0.2 mm and equal to or less than 1.0 mm in general.
[0206] The heating electrode device 20 generates heat by being
energized and heats the electrical heating glass 10. In FIG. 3, a
perspective view of a part of the heating electrode device 20 is
illustrated. As can be found from FIGS. 1 to 3, in the present
embodiment, the heating electrode device 20 includes bus bar
electrodes 21, the heat-generating conducting body 22, a power
supply connecting wire 23, and the base material layer 24. For
convenience of explanation, the base material layer 24 will be
described first.
[0207] The base material layer 24 is a layer, having one surface on
which the bus bar electrodes 21 and the heat-generating conducting
body 22 of the heating electrode device 20 are particularly
arranged, that functions as a base material of the bus bar
electrodes 21 and the heat-generating conducting body 22. The base
material layer 24 is a transparent plate-like member and is formed
of a resin. As the resin for forming the base material layer 24,
although any resin may be used as long as the resin can transmit
light with a wavelength in a visible light wavelength band (380 nm
to 780 nm), a thermoplastic resin can be preferably used. As the
thermoplastic resin, for example, a polyester resin such as
polyethylene terephthalate, polyethylene naphthalate, and amorphous
polyethylene terephthalate (A-PET), a polyolefin resin such as
polyethylene, polypropylene, polymethyl pentene, cyclic
polyolefine, an acrylic resin such as polymethyl methacrylate, a
cellulose resin such as triacetylcellulose (cellulose triacetate),
a polycarbonate resin, a styrene resin such as polystyrene and
acrylonitrile-styrene copolymer, and polyvinyl chloride can be
exemplified. In particular, an acrylic resin and polyvinyl chloride
are preferable since an acrylic resin and polyvinyl chloride are
excellent in etching resistance, weather resistance property, and
light resistance property. The thickness of the base material layer
24 is equal to or more than 20 .mu.m and equal to or less than 300
.mu.m in general. A uniaxially or biaxially stretched resin layer
is used as a resin layer forming the base material layer 24 as
necessary.
[0208] In the present embodiment, the bus bar electrodes 21 include
a first bus bar electrode 21a and a second bus bar electrode 21b.
Each of the first bus bar electrode 21a and the second bus bar
electrode 21b has a band-like shape extending in one direction (X
axis direction in FIG. 1), the first bus bar electrode 21a and the
second bus bar electrode 21b are arranged to be extended toward the
same direction (substantially parallel) with an interval. The first
bus bar electrode 21a and the second bus bar electrode 21b can have
a known form, and the width of each of the band-like electrodes is
equal to or more than 3 mm and equal to or less than 15 mm in
general.
[0209] The heat-generating conducting body 22 extends and is
arranged along a direction intersecting with both bus bar
electrodes 21a and 21b (Y-axis direction in FIG. 1) so as to
connect the first bus bar electrode 21a to the second bus bar
electrode 21b. The first bus bar electrode 21a and the second bus
bar electrode 21b are electrically connected to each other with the
heat-generating conducting body 22. The heat-generating conducting
body 22 generates heat by being energized. The plurality of
heat-generating conducting bodies 22 is arranged along the
longitudinal direction of the first bus bar electrode 21a and the
second bus bar electrode 21b (X axis direction in FIG. 1).
[0210] The heat-generating conducting body 22 has the following
shape. FIG. 4 is an enlarged view of a portion indicated by IV in
FIG. 2. Regarding a cross section of the heat-generating conducting
body 22 according to the present embodiment perpendicular to a
direction in which the heat-generating conducting body 22 extends,
when it is assumed that a length of a longer side of two sides
parallel to a direction in which the plurality of heat-generating
conducting bodies 22 is arranged (side having contact with base
material layer 24 in the present embodiment) be a width W.sub.B and
a length of the heat-generating conducting body 22 in a direction
perpendicular to the direction in which the plurality of
heat-generating conducting bodies 22 is arranged (thickness
direction of heating electrode device 20, Z axis direction in FIG.
2) be a thickness H, (H/W.sub.B)>1.0 is satisfied. That is, the
thickness H is larger than the width W.sub.B. According to this,
while reducing the width of the heat-generating conducting body 22
which causes visual recognition of the heat-generating conducting
body 22, a cross sectional area of the heat-generating conducting
body 22 can be larger by setting the thickness to be larger than
the width. Therefore, the heat-generating conducting body can be
hardly recognized in a visual way while having a high output (high
heat generation performance).
[0211] It is preferable that other parts be formed as follows while
satisfying the above conditions. In FIG. 4, reference numerals are
applied for explanation. It is preferable that an interval B
between the adjacent heat-generating conducting bodies 22
illustrated as B in FIG. 4 be equal to or more than 0.5 mm and
equal to or less than 5.00 mm. More preferably, the interval B is
equal to or more than 1.0 mm, and further preferably, the interval
B is equal to or more than 1.25 mm. In the cross section, when it
is assumed that the width be W.sub.B and the length of the side
opposite to W.sub.B be W.sub.T, it is preferable that
W.sub.B>W.sub.T, 3 .mu.m.ltoreq.W.sub.B.ltoreq.15 .mu.m, and 1
.mu.m.ltoreq.W.sub.T.ltoreq.12 .mu.m are satisfied. The cross
section is a surface that is cut to have a minimum cross sectional
area in that portion. In a case where unevenness is formed on the
surface of the heat-generating conducting body 22, a cross section
with the minimum area including the unevenness is considered.
Furthermore, it is preferable that the thickness H of the
heat-generating conducting body 22 be equal to or larger than 5
.mu.m and equal to or less than 30 .mu.m.
[0212] In addition, it is preferable that a pitch P between the
adjacent heat-generating conducting bodies 22 be equal to or more
than 0.5 mm and equal to or less than 5.00 mm. When the pitch P is
less than 0.5 mm, the heat-generating conducting bodies 22 are
arranged close to each other and easily visually recognized.
Preferably, the pitch P is equal to or more than 1.0 mm, and more
preferably, the pitch P is equal to or more than 1.25 mm. On the
other hand, if the pitch P is more than 5.00 mm, uniform heating
performance may be deteriorated.
[0213] In the thickness direction of the heating electrode device
20, when it is assumed that a surface area of one surface (base
material layer 24 in the present embodiment) of the heat-generating
conducting body 22 per length of 0.01 m in a plan view be S.sub.B
and a surface area of the other surface per length of 0.01 m in a
plan view be S.sub.T, it is preferable to satisfy 0
.mu.m.sup.2<S.sub.B-S.sub.T.ltoreq.30000 .mu.m.sup.2. Here, as
indicated by the reference L in FIG. 1, the "length" indicates a
distance from one end of the extending heat-generating conducting
body 22 to the other end. More preferably, 0
.mu.m.sup.2<S.sub.B-S.sub.T.ltoreq.15000 .mu.m.sup.2 is
satisfied. According to this, when it is assumed that a length of
the heat-generating conducting body 22 in a direction along the
surface of the base material layer 24 (horizontal direction in FIG.
4, X axis direction in FIG. 2) be the width of the heat-generating
conducting body 22, a large cross sectional area can be obtained
while suppressing an increase in the width even when the
heat-generating conducting body is produced by etching. Although it
is ideal if a rectangular shape (rectangle) can be produced, it is
difficult to produce the rectangle by etching due to nature of a
so-called side edge.
[0214] As a conductive material forming the heat-generating
conducting body 22, for example, a band-shaped member pattern
formed by etching a metal such as tungsten, molybdenum, nickel,
chromium, copper, silver, platinum, and aluminum, and an alloy such
as a nickel-chromium alloy, bronze, and brass including these
metals can be exemplified. To further enhance invisibility of the
heat-generating conducting body 22, on any one or more of four
surfaces around each heat-generating conducting body 22 (for
example, top surface in FIG. 4 (surface with width W.sub.T), lower
surface (surface with width W.sub.B), right surface, and left
surface), more preferably, on four surfaces, a light-absorbing dark
color layer can be laminated. As such a dark color layer, a layer
formed of a material such as copper oxide (CuO), copper nitride,
ferrosoferric oxide (Fe3O4), and copper-cobalt alloy can be formed
by a method such as vapor deposition, sputtering, electrolyzation,
or electroless plating as having a thickness of about 0.01 .mu.m to
1 .mu.m. As a dark color, in addition to black, a color with low
intensity such as gray, brown, dark blue, dark green, dark purple,
and dark red is appropriately selected. A hue and intensity of the
dark color can be selected based on a material, a film thickness,
and a crystal grain size of the dark color layer.
[0215] In the present embodiment, as indicated by the reference
numeral 22L in the enlarged view of the heat-generating conducting
body 22 illustrated in FIG. 1(b), the heat-generating conducting
body 22 is linearly formed, and the heat-generating conducting
bodies 22 form a parallel linear group. However, in addition to
this, the heat-generating conducting body 22 may be formed in a
band-like shape and in a wavy line shape as indicated by the
reference numeral 22M in the enlarged view of the heat-generating
conducting body 22 illustrated in FIG. 1(c).
[0216] As can be found from FIG. 1(a), the power supply connecting
wire 23 connects a power supply 40 between the first bus bar
electrode 21a and the second bus bar electrode 21b. The power
supply 40 is not particularly limited as long as the power supply
can supply power necessary for dissolving or evaporating water
droplets (frosting), freezing (frosting) and the like, any known
direct current or alternate current power supply having an
appropriate voltage, current, or frequency may be used. In a case
where the electrical heating glass 10 is applied to an automobile,
as the power supply 40, for example, a battery such as a lead
storage battery and a lithium ion storage battery provided in the
automobile can be used as a DC power supply. At this time, for
example, a positive electrode of the battery can be connected to
the second bus bar electrode 21b, and a negative electrode can be
connected to the first bus bar electrode 21a. Naturally, a
dedicated power supply (battery cell, generator, and the like) may
be used separately. Furthermore, in a case of a railway vehicle
powered by an electric motor, DC or AC power supplied from an
overhead wire can be used by appropriately converting the power
into an appropriate voltage or current. The power supply connecting
wire 23 may have a known structure.
[0217] The adhesive layer 14 bonds the base material layer 24
including the bus bar electrodes 21 and the heat-generating
conducting bodies 22 to the second panel 15. The adhesive layer 14
can have the same structure as the adhesive layer 12.
[0218] With the above components, the electrical heating glass 10
is as follows. As can be found from FIG. 2, the adhesive layer 12
is laminated on one surface of the first panel 11, and the base
material layer 24 is laminated on the first panel 11 via the
adhesive layer 12. The heating electrode device 20 is arranged on a
surface of the base material layer 24 opposite to the surface on
which the adhesive layer 12 is arranged. Although the second panel
15 is arranged on the surface of the heating electrode device 20
opposite to the surface on which the base material layer 24 is
arranged, the adhesive layer 14 is arranged to fill a space between
the base material layer 24 and the heating electrode device 20 and
the second panel 15. Accordingly, the second panel 15 is laminated
on the base material layer 24 and the heating electrode device
20.
[0219] Such a heating electrode device 20 and the electrical
heating glass 10 including the same can be manufactured, for
example, as follows. FIGS. 5(a) to 5(d) are views for
explanation.
[0220] First, as illustrated in FIG. 5(a), a metal foil 22' is
bonded to and laminated on the base material layer 24 formed of a
resin film via an adhesive layer to manufacture a laminate. Next,
as illustrated in FIG. 5(b), a photosensitive resist layer 80 is
applied and formed on the metal foil 22' of the laminate.
[0221] Next, a photomask is prepared that has a desired pattern,
for example, a light-shielding pattern based on a plan view pattern
of the heating electrode device 20 including the heat-generating
conducting bodies 22 and the bus bar electrodes 21a and 21b
arranged in a pattern in which band-like linear lines are arranged
in parallel as illustrated in FIG. 1(b). Then, the photomask is
placed in close contact with the photosensitive resist layer 80.
Then, the photosensitive resist layer 80 is exposed to ultraviolet
rays through the photomask, and the photomask is removed, and
sequentially, the photosensitive resist layer which is not exposed
is dissolved and removed by known developing processing, and a
resist pattern layer 80' having a shape matching a desired pattern
80a is formed on the metal foil 22' as illustrated in FIG. 5(c).
Here, in FIG. 5(c), positions and sizes of the heat-generating
conducting bodies 22 to be formed are indicated by broken lines
with a light color as a reference. As can be found from FIG. 5(c),
this example is formed so that a distance from an edge of the
resist pattern 80a formed on the resist pattern layer 80c to an
edge of the heat-generating conducting body 22 to be formed is C.
It is preferable that the distance C be equal to or longer than 5
.mu.m and equal to or shorter than 30 .mu.m. As a result, the
heat-generating conducting body 22 having the above form can be
obtained by etching.
[0222] Next, etching (corrosion) processing using corrosive liquid
is performed on the laminate from the resist pattern layer 80', and
the resist pattern layer 80' and the metal foil 22' are corroded
and removed as illustrated in FIG. 5(d). Then, the resist pattern
layer is dissolved and removed (remove coating). As described
above, a laminated structure in which the heat-generating
conducting bodies 22 and the bus bar electrodes 21a and 21b with a
predetermined pattern having a plan view shape in FIG. 1(a) and a
cross section shape in FIG. 2 are formed on the base material layer
24 is manufactured.
[0223] Next, the first panel 11, the adhesive layer 12, the
laminated structure including the base material layer 24 and the
heating electrode device 20, the adhesive layer 14, and the second
panel 15 are laminated in this order, and the plurality of layers
is bonded, laminated, and integrated to each other. According to
the above process, the electrical heating glass 10 illustrated in
the plan view in FIG. 1(a) and the cross-sectional view in FIG. 2
is manufactured.
[0224] According to the electrical heating glass 10 described
above, a heat-generating conducting body of which a shape of the
cross section is close to a rectangle can be obtained by etching,
the thickness and the cross sectional area can be increased while
the length in the width direction is reduced than a heat-generating
conducting body having a trapezoidal cross section in which a
difference between an upper base and a lower base is large.
[0225] The electrical heating glass 10 is used and acts, for
example, as follows. Here, as an example, a case where the
electrical heating glass 10 is applied to a front panel of an
automobile will be described. That is, in the embodiment in FIG. 1,
the electrical heating glass 10 is arranged at a position of the
front panel of the automobile, and the power supply connecting wire
23 is connected to the power supply 40 via a switch 50 at this
time, and the heat-generating conducting body 22 can be heated via
the bus bar electrodes 21. In the present embodiment, a battery
provided in the automobile is used as the power supply 40. When the
switch 50 is closed, the power supply 40 supplies a current. Since
generated Joule heat of the heat-generating conducting body 22
heats the first panel 11 and the second panel 15 of the
heat-generating conducting body 22, the temperature of the
electrical heating glass 10 that functions as a front panel
increases, and this eliminates freezing and fogging. In the present
embodiment, since the heat generation can be facilitated by having
a large cross section of the heat-generating conducting body 22,
freezing and fogging can be eliminated earlier.
Second Embodiment
[0226] FIG. 6(a) is a view for explaining one embodiment and is a
conceptual view of an electrical heating glass 110 in a plan view.
FIG. 6(b) is an enlarged view of a portion indicated by Ia in FIG.
6(a), and an enlarged view of a heat-generating conducting body 122
which is an example of a heat-generating conducting body 122 is
illustrated. FIG. 7 is a cross-sectional view taken along a line
VII-VII illustrated in FIG. 6 and is a view for explaining a layer
structure along a thickness direction of the electrical heating
glass 110. Such an electrical heating glass 110 is, for example,
included in an automobile as a windshield of an automobile. In
addition, the electrical heating glass 10 can be used as a window
in a place having a so-called glass window, for example, a window
of a vehicle such as a train, an aircraft, and a ship, including
the automobile, and a window of a building.
[0227] As can be found from FIGS. 6 and 7, the electrical heating
glass 110 has a plate-like shape as a whole, and a plurality of
layers is laminated along the thickness direction (Z-axis direction
in FIGS. 6 and 7). More specifically, as illustrated in the
cross-sectional view in FIG. 7, the electrical heating glass 110
according to the present embodiment includes a first panel 111, an
adhesive layer 112, a heating electrode device 120, an adhesive
layer 114, and a second panel 115. Each component will be described
below.
[0228] The first panel 111 and the second panel 115 are plate-like
members having translucency, that is, transparent plate-like
members and are arranged in substantially parallel to each other
with an interval between plate surfaces facing to each other. The
electrical heating glass 110 has a so-called double panel
structure. Here, the plate surface indicates two planes that are
parallel to the XY plane and face to each other among the surfaces
of the first panel 111 and the second panel 115 in FIG. 7. A part
of the heating electrode device 120 is arranged between the first
panel 111 and the second panel 115, and the heating electrode
device 120 and the panels are integrated with the adhesive layers
112 and 114. The first panel 111 and the second panel 115 can be
formed of a plate glass. For these panels, the same plate glass can
be used as that used for a window normally provided in a facility
(for example, vehicle and building) to which the electrical heating
glass 110 is applied. For example, sheet glass, float plate glass,
reinforced plate glass, partial plate glass, and the like made of
soda-lime glass (blue plate glass), borosilicate glass (white plate
glass), quartz glass, soda glass, and potassium glass can be
exemplified. In addition, the panels may have a three-dimensionally
curved bent portion as necessary. However, the panel is not
necessarily formed of a glass plate, and may be a resin plate made
of a resin such as an acrylic resin or a polycarbonate resin.
However, from the viewpoint of weather resistance property, heat
resistance property, transparence, and the like, it is preferable
that the plate be a plate glass. Although thicknesses of the first
panel 111 and the second panel 115 are not particularly limited,
the thicknesses are equal to or more than 1.5 mm and equal to or
less than 5 mm in general.
[0229] The adhesive layer 112 is a layer formed of an adhesive
laminated on the surface of the first panel 111 on the side of the
second panel 115 and bonds the base material layer 124 to the first
panel 111. Although the adhesive is not particularly limited, a
polyvinyl butyral resin can be used from the viewpoint of
adhesiveness, weather resistance property, heat resistance
property, and the like. Although the thickness of the adhesive
layer 112 is not particularly limited, the thickness is equal to or
more than 0.2 mm and equal to or less than 1.0 mm in general.
[0230] The heating electrode device 120 generates heat by being
energized and heats the electrical heating glass 110. In FIG. 8, a
perspective view of a part of the heating electrode device 120 is
illustrated. As can be found from FIGS. 6 to 8, in the present
embodiment, the heating electrode device 120 includes bus bar
electrodes 121, the heat-generating conducting body 122, a power
supply connecting wire 123, and the base material layer 124. For
convenience of explanation, the base material layer 124 will be
described first.
[0231] The base material layer 124 is a layer, having one surface
on which the bus bar electrodes 121 and the heat-generating
conducting body 122 of the heating electrode device 120 are
particularly arranged, that functions as a base material of the bus
bar electrodes 121 and the heat-generating conducting body 122. The
base material layer 124 is a transparent plate-like member and is
formed of a resin. As a resin for forming the base material layer
124, although any resin may be used as long as the resin can
transmit light with a wavelength in a visible light wavelength band
(380 nm to 780 nm), a thermoplastic resin can be preferably used.
As a thermoplastic resin, for example, a polyester resin such as
polyethylene terephthalate, polyethylene naphthalate, and amorphous
polyethylene terephthalate (A-PET), a polyolefin resin such as
polyethylene, polypropylene, polymethyl pentene, cyclic
polyolefine, an acrylic resin such as polymethyl methacrylate, a
cellulose resin such as triacetylcellulose (cellulose triacetate),
a polycarbonate resin, a styrene resin such as polystyrene and
acrylonitrile-styrene copolymer, and polyvinyl chloride can be
exemplified. In particular, an acrylic resin and polyvinyl chloride
are preferable since an acrylic resin and polyvinyl chloride are
excellent in etching resistance, weather resistance property, and
light resistance property. The thickness of the base material layer
124 is equal to or more than 20 .mu.m and equal to or less than 300
.mu.m in general. A uniaxially or biaxially stretched resin layer
is used as a resin layer forming the base material layer 124 as
necessary.
[0232] In the present embodiment, the bus bar electrodes 121
include a first bus bar electrode 121a and a second bus bar
electrode 121b. Each of the first bus bar electrode 121a and the
second bus bar electrode 121b has a band-like shape extending in
one direction (X axis direction in FIG. 6), the first bus bar
electrode 121a and the second bus bar electrode 121b are arranged
to be extended toward the same direction (substantially parallel)
with an interval. The first bus bar electrode 121a and the second
bus bar electrode 121b can have a known form, and the width of each
of the band-like electrodes is equal to or more than 3 mm and equal
to or less than 15 mm in general.
[0233] The heat-generating conducting body 122 extends and is
arranged along a direction intersecting with both bus bar
electrodes 121a and 21b (Y-axis direction in FIG. 6) so as to
connect the first bus bar electrode 121a to the second bus bar
electrode 121b. The first bus bar electrode 121a and the second bus
bar electrode 121b are electrically connected to each other with
the heat-generating conducting body 122. The heat-generating
conducting body 122 generates heat by being energized. The
plurality of heat-generating conducting bodies 122 is arranged
along the longitudinal direction of the first bus bar electrode
121a and the second bus bar electrode 121b (X axis direction in
FIG. 6).
[0234] The heat-generating conducting body 122 has the following
shape. As illustrated in FIG. 6, when it is assumed that an
interval between the first bus bar electrode 121a and the second
bus bar electrode 121b be D (mm) and a length of a single
heat-generating conducting body 122 between the first bus bar
electrode 121a and the second bus bar electrode 121b be L (mm),
that is, when it is assumed that a distance between both ends of
the heat-generating conducting body 122 be D (mm) and the length
along the heat-generating conducting body 122 between the both ends
be L (mm), 1.02D.ltoreq.L<1.50D is satisfied. As a result, a
form to prevent a beam of light can be formed, and unnecessary
increase in the resistance of the heat-generating conducting body
can be prevented, and accordingly, a heating value can be
maintained at a high level. That is, it is possible to prevent a
beam of light and to efficiently remove frost and fogging.
[0235] Although a specific form of the heat-generating conducting
body is not particularly limited as long as the above condition is
satisfied, to more reliably prevent a beam of light, it is
preferable that the heat-generating conducting body 122 has a wavy
form in a plan view (point of sight in FIG. 6).
[0236] Furthermore, it is preferable that the heat-generating
conducting body 122 be configured as follows. FIG. 9 is an enlarged
view of a portion indicated by IX in FIG. 7. Regarding the
heat-generating conducting body 122, in the thickness direction of
the heating electrode device 120, when it is assumed that a surface
area of one surface of (base material layer 124 in the present
embodiment) the heat-generating conducting body 122 per length of
0.01 m in a plan view be S.sub.B (.mu.m.sup.2) and a surface area
of the other surface per length of 0.01 m in a plan view be S.sub.T
(.mu.m.sup.2), it is preferable to satisfy 0
.mu.m.sup.2<S.sub.B-S.sub.T.ltoreq.30000 .mu.m.sup.2. Here, the
"length" is a distance between one end and the other end when a
certain portion of the extending heat-generating conducting body
122 having a length of 0.01 m is extracted. More preferably, 0
.mu.m.sup.2<S.sub.B-S.sub.T.ltoreq.15000 .mu.m.sup.2 is
satisfied. Accordingly, when the heat-generating conducting body
122 is produced with a width with which the heat-generating
conducting body 122 cannot be visually recognized, the cross
sectional area can be large, and a higher output (heating value)
can be obtained. Although it is ideal if a rectangular shape
(rectangle) can be produced, it is difficult to produce the
rectangle by etching due to nature of a so-called side edge.
[0237] It is preferable that other parts be formed as follows while
satisfying the above conditions. In FIG. 9, reference numerals are
applied for explanation. It is preferable that an interval between
the adjacent heat-generating conducting bodies 122 illustrated as B
in FIG. 9 be equal to or more than 0.5 mm and equal to or less than
5.00 mm. More preferably, the interval is equal to or more than 1.0
mm, and further preferably, the interval B is equal to or more than
1.25 mm. In the cross section, when it is assumed that the width be
W.sub.B (.mu.m) and the length of the side opposite to W.sub.B be
W.sub.T (.mu.m), it is preferable that W.sub.B>W.sub.T, 3
.mu.m.ltoreq.W.sub.B.ltoreq.15 .mu.m, and 1
.mu.m.ltoreq.W.sub.T.ltoreq.12 .mu.m be satisfied. The cross
section is a surface that is cut to have a minimum cross sectional
area in that portion. In a case where unevenness is formed on the
surface of the heat-generating conducting body 122, a cross section
with the minimum area including the unevenness is considered.
Furthermore, it is preferable that the thickness H (.mu.m) of the
heat-generating conducting body 122 be equal to or larger than 5
.mu.m and equal to or less than 30 .mu.m.
[0238] In addition, it is preferable that a pitch P (mm) between
the adjacent heat-generating conducting bodies 122 be equal to or
more than 0.5 mm and equal to or less than 5.00 mm. When the pitch
P (mm) is less than 0.5 mm, the heat-generating conducting bodies
122 are arranged close to each other and easily visually
recognized. Preferably, the pitch P (mm) is equal to or more than
1.0 mm, and more preferably, the pitch P (mm) is equal to or more
than 1.25 mm. On the other hand, if the pitch P (mm) is more than
5.00 mm, uniform heating performance may be deteriorated.
[0239] As a conductive material forming the heat-generating
conducting body 122, for example, a band-shaped member pattern
formed by etching a metal such as tungsten, molybdenum, nickel,
chromium, copper, silver, platinum, and aluminum, and an alloy such
as a nickel-chromium alloy, bronze, and brass including these
metals can be exemplified.
[0240] As can be found from FIG. 6(a), the power supply connecting
wire 123 connects a power supply 140 between the first bus bar
electrode 121a and the second bus bar electrode 121b. The power
supply 140 is not particularly limited as long as the power supply
can supply power necessary for dissolving or evaporating water
droplets (fogging), freezing (frosting) and the like, any known
direct current or alternate current power supply having an
appropriate voltage, current, or frequency may be used. In a case
where the electrical heating glass 110 is applied to an automobile,
for example, as the power supply 140, a battery such as a lead
storage battery and a lithium ion storage battery provided in the
automobile can be used as a DC power supply. At this time, for
example, a positive electrode of the battery can be connected to
the second bus bar electrode 121b, and a negative electrode can be
connected to the first bus bar electrode 121a. Naturally, a
dedicated power supply (battery cell, generator, and the like) may
be used separately. Furthermore, in a case of a railway vehicle
powered by an electric motor, DC or AC power supplied from an
overhead wire can be used by appropriately converting the power
into an appropriate voltage or current. The power supply connecting
wire 123 may have a known structure.
[0241] The adhesive layer 114 bonds the base material layer 124
including the bus bar electrodes 121 and the heat-generating
conducting bodies 122 to the second panel 115. The adhesive layer
114 can have the same structure as the adhesive layer 112.
[0242] With the above components, the electrical heating glass 110
is formed as follows. As can be found from FIG. 7, the adhesive
layer 112 is laminated on one surface of the first panel 111, and
the base material layer 124 is laminated on the first panel 111 via
the adhesive layer 112. The heating electrode device 120 is
arranged on a surface of the base material layer 124 opposite to
the surface on which the adhesive layer 112 is arranged. Although
the second panel 115 is arranged on the surface of the heating
electrode device 120 opposite to the surface on which the base
material layer 124 is arranged, the adhesive layer 114 is arranged
to fill a space between the base material layer 124 and the heating
electrode device 120 and the second panel 115. Accordingly, the
second panel 115 is laminated on the base material layer 124 and
the heating electrode device 120.
[0243] Such a heating electrode device 120 and the electrical
heating glass 110 including the same can be manufactured, for
example, as follows. FIGS. 10(a) to 10(d) are views for
explanation.
[0244] First, as illustrated in FIG. 10(a), a metal foil 122' is
bonded to and laminated on the base material layer 124 formed of a
resin film via an adhesive layer to manufacture a laminate. Next,
as illustrated in FIG. 10(b), a photosensitive resist layer 180 is
applied and formed on the metal foil 122' of the laminate.
[0245] Next, a photomask is prepared that has a light-shielding
pattern based on a plan view pattern of the heat-generating
conducting bodies 122 and the bus bar electrodes 121 which is a
desired pattern. Then, the photomask is placed in close contact
with the photosensitive resist layer 180. Then, the photosensitive
resist layer 180 is exposed to ultraviolet rays through the
photomask, and the photomask is removed, and sequentially, the
photosensitive resist layer which is not exposed is dissolved and
removed by known developing processing, and a resist pattern layer
180' having a shape matching a desired pattern 180a is formed on
the metal foil 122' as illustrated in FIG. 10(c). Here, in FIG.
10(c), positions and sizes of the heat-generating conducting bodies
122 to be formed are indicated by broken lines with a light color
as a reference. As can be found from FIG. 10(c), this example is
formed so that a distance from an edge of the resist pattern 180a
formed on the resist pattern layer 180c to an edge of the
heat-generating conducting body 122 to be formed is C (.mu.m). It
is preferable that the distance C be equal to or longer than 5
.mu.m and equal to or shorter than 30 .mu.m. As a result, the
heat-generating conducting body 122 having the above form can be
obtained by etching.
[0246] Next, etching (corrosion) processing using corrosive liquid
is performed on the laminate from the resist pattern layer 180',
and the resist pattern layer 180' and the metal foil 122' are
corroded and removed as illustrated in FIG. 10(d). Then, the resist
pattern layer is dissolved and removed (remove coating). As
described above, a laminated structure in which the heat-generating
conducting bodies 122 and the bus bar electrodes 121a and 21b with
a predetermined pattern having a plan view shape in FIG. 6(a) and a
cross section shape in FIG. 7 are formed on the base material layer
124 is manufactured.
[0247] In the present embodiment, since the cross section of the
heat-generating conducting body 122 is defined as described above,
the heat-generating conducting body 122 can be formed with high
productivity.
[0248] Next, the adhesive layer 114 and the second panel 115 are
laminated on the laminated structure, including the first panel
111, the adhesive layer 112, and the heating electrode device 120,
in this order, and the plurality of layers is bonded, laminated,
and integrated with each other. According to the above process, the
electrical heating glass 110 illustrated in the plan view in FIG.
6(a) and the cross-sectional view in FIG. 7 is manufactured.
[0249] According to the manufacturing method for the electrical
heating glass 110 described above, a heat-generating conducting
body of which a shape of the cross section is close to a rectangle
can be obtained by etching, the thickness and the cross sectional
area can be increased while the length in the width direction is
reduced than a heat-generating conducting body having a trapezoidal
cross section in which a difference between an upper base and a
lower base is large.
[0250] The electrical heating glass 110 is used and acts, for
example, as follows. Here, as an example, a case where the
electrical heating glass 110 is applied to a front panel of an
automobile will be described. That is, in the embodiment in FIG. 6,
the electrical heating glass 110 is arranged at a position of the
front panel of the automobile, and the power supply connecting wire
123 is connected to the power supply 140 via a switch 150 at this
time, and the heat-generating conducting body 122 can be heated via
the bus bar electrodes 121. In the present embodiment, a battery
provided in the automobile is used as the power supply 140. When
the switch 150 is closed, the power supply 140 supplies a current.
Since generated Joule heat of the heat-generating conducting body
122 heats the first panel 111 and the second panel 115 of the
heat-generating conducting body 122, the temperature of the
electrical heating glass 110 that functions as a front panel
increases, and this eliminates freezing and fogging. In the present
embodiment, since it is possible to prevent a beam of light and
facilitate heat generation by setting the length of the
heat-generating conducting body 122 to a length within a
predetermined range, freezing and fogging can be efficiently
eliminated while preventing a beam of light.
EXAMPLE
[0251] In the example, a defrosting time and a beam of light are
evaluated by changing a ratio of a length L (mm) of the
heat-generating conducting body along the heat-generating
conducting body relative to a distance D (mm) between ends of the
heat-generating conducting body.
[0252] An electrical heating glass is produced as the example of
the electrical heating glass 110. At this time, a vertical length
and a horizontal length of a heat generating area are 300 mm, and a
nickel electrode with a thickness of 50 .mu.m and a width of 20 mm
is provided on each end. It is assumed that the thickness of each
heat-generating conducting body be 12 .mu.m and a pitch between
adjacent heat-generating conducting bodies be 1.25 mm. Table 1
illustrates a relationship between D and L in each example.
[0253] A test regarding a beam of light has been carried out as
follows. First, the produced electrical heating glass is irradiated
with light from a light source ((light of automobile manufactured
by SUBARU CORPORATION, FORESTER (registered trademark)) arranged at
a position 4 m separated from the electrical heating glass. At this
time, the electrical heating glass is placed with an inclination of
60 degrees with respect to the vertical direction. Subsequently,
the electrical heating glass is viewed from an opposite side of the
light source across the electrical heating glass and from a
position that is 50 cm separated from the electrical heating glass.
In a case where a beam of light is generated, B is written, and in
a case where a beam of light is not generated, A is written.
[0254] On the other hand, a test regarding defrosting (defroster
performance test) has been carried out as conforming to JIS D
4501-1994, and a specimen is placed with an inclination with 60
degrees with respect to the vertical direction as in the test
regarding the beam of light. In a state where the electrical
heating glass is covered with ice, a time from the start of
energization to a time when the ice is eliminated from an entire
surface of the electrical heating glass is measured. Here, a
voltage applied to the electrical heating glass is 4.2 V.
[0255] In Table 1, in addition to the length of the heat-generating
conducting body, the defrosting time and whether the beam of light
is generated are illustrated.
TABLE-US-00001 TABLE 1 LENGTH OF HEAT- GENERATING DEFROSTING
CONDUCTING TIME BEAM OF BODY (mm) (minute) LIGHT EXAMPLE 1 1.02 D
4.1 A EXAMPLE 2 1.10 D 4.4 A EXAMPLE 3 1.30 D 4.9 A COMPARATIVE
1.00 D 4.0 B EXAMPLE 1 COMPARATIVE 1.50 D 6.0 A EXAMPLE 2
[0256] As can be found from Table 1, by satisfying the present
embodiment, the beam of light can be prevented, and the preferable
defrosting time can be obtained.
Third Embodiment
[0257] In the following description, terms of "plate", "sheet", and
"film" are not distinguished from each other based on a difference
in the name. For example, the term "sheet" is a concept that may
include a member which can be called "plate" or "film", and these
members are not necessarily distinguished from each other only
based on the difference in the name. In addition, terms used herein
for specifying shapes and geometric conditions and degrees thereof
(for example, terms including "identical", "same", and "equal" and
other terms indicating physical properties such as values of
lengths and angles) are not limited to strict meanings and are
interpreted as including a range of terms that can be expected to
have a similar function.
[0258] In addition, each component illustrated in the drawing
attached to the specification has a size and a position that do not
necessarily coincide with those of a real one, and the components
are illustrated as appropriately changing the scale, the
dimensional ratio in the in the vertical and horizontal directions,
the arrangement relationship, and the like.
[0259] First, regarding "prevention of generation of a beam of
light", "antiglare", and "achievement of both of prevention of
generation of a beam of light and antiglare" regarding a
heat-generating plate (refer to reference numeral "210" in FIG. 14)
including heat-generating conductors including a plurality of
conductive thin wires, the findings of the inventors will be
described.
[0260] <Prevention of Generation of Beam of Light>
[0261] As a result of intensive research, the inventors of the
present invention have newly found that a thin-line heat-generating
conductor (conductive thin wire) may cause a beam of light and that
a beam of light is easily generated especially in a case where a
large number of conductive thin wires are arranged in the same
pattern. Generally, a beam of light is caused by diffraction of
light. For example, when light enters a transparent heat-generating
plate, the incident light is diffracted by each conductive thin
wire. Particularly, diffraction light beams caused by conductive
thin wires arranged in the same pattern interfere with each other
and easily cause a beam of light that is elongated in a radial
shape and can be visually recognized.
[0262] The inventors of the present invention have focused on a
generation mechanism of a beam of light and have found that
generation of the beam of light that can be visually recognized can
be effectively prevented by irregularly arranging the plurality of
conductive thin wires. That is, the inventors of the present
invention have newly found that, from the viewpoints of preventing
the generation of the beam of light that can be visually
recognized, "the plurality of conductive thin wires linearly
arranged in parallel" and "the plurality of conductive thin wires
arranged in the same pattern" are not preferable and that "the
plurality of conductive thin wires irregularly arranged with
various curvatures in a plan view" is preferable (refer to
reference numeral "230" in FIG. 15 described later). In a plan
view, a shape of the heat-generating plate 210 including the
heat-generating conductor 230 observed from a normal direction of a
front and rear surfaces of the heat-generating plate 210 (Z
direction in FIG. 15 to be described later), and FIG. correctly
illustrates the shape of the heat-generating conductor 230 in a
plan view.
[0263] <About Antiglare>
[0264] In general, from a viewpoint of realizing an excellent
visibility, a window that causes a phenomenon such as glare which
may interfere the field of view is not preferable. For example, in
a case where a transparent heat-generating plate is used for a
vehicle window, when a so-called glare phenomenon such as dazzle or
blur in which the conductive thin wire is visually recognized with
sparkle in a case of a specific combination of an incident angle
and a line of sight of an observer due to light reflection by the
surface of the conductive thin wire (heat-generating conductor)
occurs in light observed through the vehicle window, a field of
view of a vehicle occupant such as a driver may be impaired, and in
addition, eyestrain of the vehicle occupant is increased.
Accordingly, even in a case where the "transparent heat-generating
plate including the plurality of conductive thin wires irregularly
arranged with various curvatures in a plan view" described above is
used for a window, it is required to maintain excellent visibility
by preventing a phenomenon such as glare.
[0265] Although a part of the light entering the transparent
heat-generating plate including the plurality of conductive thin
wires is reflected by each conductive thin wire, specific light
reflection aspects in the conductive thin wires vary according to
the shape of the cross sectional area of each conductive thin
wire.
[0266] FIGS. 11A and 11B are diagrams for explaining a relationship
between a cross sectional shape of the thin linear heat-generating
conductor 230 and a light reflection aspect. FIG. 11A illustrates
an example of a heat-generating conductor 230 having a rectangular
cross sectional area, and FIG. 11B illustrates an example of a
heat-generating conductor 230 having a non-rectangular cross
sectional area. Here, the cross sectional area indicates a cross
section obtained by cutting a heat-generating conductor (conductive
thin wire) along a direction perpendicular to an extending
direction of the heat-generating conductor (conductive thin wire)
(for example, direction of center line of conductive thin wire
(length direction)). For example, FIGS. 17A and 17B to be described
later illustrate the cross section of the heat-generating
conductor. In addition, in FIGS. 17A and 17B, the extending
direction is a Y direction, and the cross sectional area has a ZX
plane.
[0267] As illustrated in FIG. 11A, the cross section of each
heat-generating conductor 230 has a rectangular shape that is
defined by two sides S2 and S4 extending along a direction same as
an incident direction L of light and two sides 51 and S3 extending
along a direction perpendicular to the incident direction L, light
reflected by the side 51 in the direction perpendicular to the
incident direction L travels in a direction opposite to the
incident direction L, and the other sides S2 to S4 do not reflect
light traveling in the incident direction L in principle.
Therefore, if the cross sectional area of the heat-generating
conductor 230 included in the heat-generating plate has a
rectangular shape, a light component reflected by the
heat-generating conductor 230 of the light traveling in the
incident direction L does not enter and interfere a visual field of
a vehicle occupant who observes light through the heat-generating
plate (vehicle window).
[0268] However, in reality, it is very difficult to accurately
process the cross section of the heat-generating conductor 230 into
the rectangular shape, and especially, in a case where the
heat-generating conductor 230 is formed by etching (corrosion
processing), the heat-generating conductor 230 usually has a
non-rectangular cross sectional area as illustrated in FIG. 11B by
a so-called side etching phenomenon. The heat-generating conductor
230 illustrated in FIG. 11B is common to that in FIG. 11A in that
two sides S1 (upper bottom) and S3 (lower bottom) extending along a
direction perpendicular to the incident direction L of the light
are included. However, extending directions of the sides S2 (first
inclined portion) and S4 (second inclined portion) connecting the
sides S1 and S3 extending in the direction perpendicular to the
incident direction L do not coincide with the incident direction L.
That is, each of the side S2 extending between one ends of the
sides S1 and S3 extending along the direction perpendicular to the
incident direction L and the side S4 extending between the other
ends is curved with an inclination with respect to the incident
direction L. Therefore, a part of the light traveling in the
incident direction L is reflected by the inclined sides (referred
to as "inclined portion" below) S2 and S4 of the heat-generating
conductor 230 and subsequently travels in various directions
different from the original incident direction L. Particularly,
actual observed light entering the heat-generating plate (vehicle
window and the like) does not necessarily include only optical
components for traveling in one direction, the observed light
includes optical components for travelling in various directions in
most cases. Therefore, a part of the light reflected by the
inclined portions S2 and S4 of the heat-generating conductor 230
may enter the visual field of the vehicle occupant. Such reflected
light is light for traveling in a direction different from an
original traveling direction, and the reflected light enters the
visual field of a user (observer observing transmitted light) at an
unexpected angle and causes glare such as dazzle or blur.
Therefore, the reflected light is not preferable in a viewpoint for
securing excellent visibility.
[0269] The inventors of the present invention have focused on a
light reflection mechanism by the conductive thin wire and have
newly found that glare such as dazzle or blur can be effectively
prevented by adjusting a cross sectional shape of the conductive
thin wire so that the inclined portion of each conductive thin wire
has various angles as an inclination angle in the cross section.
That is, if the inclination angles of the inclined portions of the
cross sectional areas of all the conductive thin wires included in
the heat-generating plate are common to each other, dazzle or blur
may be emphasized in light observed by the user through the
heat-generating plate. Therefore, the inventors of the present
invention have newly found that glare is effectively prevented by
giving various angles (inclination) to the plurality of conductive
thin wires in the cross section.
[0270] <Achievement of Both of Prevention of Occurrence of Beam
of Light and Antiglare>
[0271] In the window using the heat-generating plate, the
conductive thin wire exists in the field of view of the user.
However, from the viewpoint of realizing clear visibility, it is
preferable to sufficiently thin the conductive thin wire so that
the conductive thin wire is not visually recognized as
possible.
[0272] However, when the conductive thin wire is thinned, it is
difficult to apply angle variations to the inclination angle of the
inclined portion of the cross sectional area of the conductive thin
wire. That is, to realize a gentle inclination by reducing the
inclination angle of the inclined portion of the cross sectional
area in the extremely thin conductive thin wire, for example, in
the example illustrated in FIG. 11B, a difference between lengths
of a side S1 (upper bottom) and a side S3 (lower bottom) is
increased, and the sufficient length of the shorter side S1 (upper
bottom) cannot be especially secured. When the upper bottom S1 of
the cross sectional area of the conductive thin wire is extremely
short, a possibility that the conductive thin wire is disconnected
due to a manufacturing error and the like is increased.
[0273] Therefore, by mixedly providing relatively thick portions
and relatively thin portions in each conductive thin wire, desired
angle variations can be easily applied to the inclination angle of
the inclined portion of the cross sectional area of each conductive
thin wire. In particular, it is desirable to realize a "gentle
inclination with a small inclination angle" in the relatively thick
inclined portion of the conductive thin wire and realize a "steep
inclination with a large inclination angle" in the relatively thin
inclined portion of the conductive thin wire from the viewpoint of
preventing the disconnection of the conductive thin wire.
[0274] On the other hand, regarding the plurality of conductive
thin wires arranged with various curvatures to prevent a beam of
light, under constraints on the arrangement space, the width of the
conductive thin wire is easily increased in a portion with a
smaller curvature and a smaller curve than a portion with a larger
curvature and a larger curve. Therefore, it is preferable to vary
the inclination angle of the inclined portion by making the
inclination of the inclined portion of the cross sectional area be
gentle by thickening the portion with a small curvature in each
conductive thin wire and making the inclination of the inclined
portion of the cross sectional area be steep by thinning the
portion with a large curvature.
[0275] As a method for forming the conductive thin wire, for
example, a method for forming the conductive thin wire with a
desired wiring shape by etching a film to be the conductive thin
wire is preferably used. In a case where the conductive thin wire
is formed by etching, the conductive thin wire having various
inclined portions can be formed by making a degree of erosion of a
film by etching be relatively stronger to form a steep inclination
of the inclined portion and making a degree of erosion of a film by
etching be relatively weaker to form a gentle inclination of the
inclined portion. When the inclination of the inclined portion in
the thin portion of the conductive thin wire is made to be gentle
by etching, erosion of the side of the film covered with a resist
and etched is more proceeded than erosion of other portions, and
all the film portion covered with the resist may be eroded before
etching on the entire conductive thin wire is completed, and the
conductive thin wire may be disconnected.
[0276] Based on the analysis and findings, the inventors of the
present invention have newly acquired knowledges such that
prevention of occurrence of a beam of light and antiglare can be
achieved at a high level by making the "inclination of the cross
sectional area of the large curvature portion (first large
curvature portion 231b in FIG. 15 to be described later) of the
cross sectional area of the conductive thin wire (conductive main
thin wire and conductive sub thin wire to be described later) be
larger than the inclination of the cross sectional area of the
small curvature portion (first small curvature portion 231a in FIG.
15 to be described later).
[0277] It is preferable to realize that "the conductive thin wire
has different inclination of the cross sectional area according to
the curvature" across the entire heat-generating plate (conductive
thin wire). However, such inclinations may be realized only in a
part of the heat-generating plate (conductive thin wire). For
example, in a case where the heat-generating plate is applied to a
vehicle window, the inclination of the cross sectional area of the
conductive thin wire may be determined according to the curvature
in a range corresponding to a part of or all of a normal visual
field of a vehicle occupant in the vehicle window. In addition, in
only a part of the conductive thin wire, the inclination of the
cross sectional area of the conductive thin wire may be determined
according to the curvature.
[0278] Hereinafter, a specific embodiment of the present invention
based on the above analysis and findings will be described.
[0279] FIG. 12 is a perspective view for schematically illustrating
an automobile (vehicle) 201 on which a battery (power supply) 207
is mounted.
[0280] In general, the automobile 201 has various windows such as a
front window, a rear window, side windows, and a sunroof window.
Although a transparent heat-generating plate 210 according to the
embodiment of the present invention can be applied to any window,
an example in which the front window 205 is formed of the
transparent heat-generating plate 210 will be described below.
[0281] FIG. 13 is a front view of the front window 205 formed of
the transparent heat-generating plate 210.
[0282] The heat-generating plate 210 in this example includes a
first transparent plate 211, a second transparent plate 212, and a
conductor sheet 220 arranged between the first transparent plate
211 and the second transparent plate 212. The conductor sheet 220
includes a pair of bus bars 225 connected to a battery 207 via a
wiring portion 215 and a heat-generating conductor (refer to
reference numeral "230" in FIG. 14 to be described later) arranged
between the bus bars 225 and connected to each of the pair of bus
bars 225. When the battery 207 applies a voltage to the pair of bus
bars 225, the heat-generating conductor connected to the pair of
bus bars 225 is energized and generates heat by resistance heating.
Although the conductor sheet 220 including the bus bars 225 and the
heat-generating conductor is arranged in a sealed space between the
first transparent plate 211 and the second transparent plate 212,
the conductor sheet 220 is electrically connected to the battery
207 provided outside via the wiring portions 215 extending from the
bus bars 225 to the outside of the first transparent plate 211 and
the second transparent plate 212.
[0283] In the examples illustrated in FIGS. 12 and 13, the
heat-generating plate 210 (front window 205), the first transparent
plate 211, and the second transparent plate 212 are curved.
However, for easy understanding, in other figures, the
heat-generating plate 210, the first transparent plate 211, and the
second transparent plate 212 having plate-like shape are
illustrated.
[0284] FIG. 14 is a cross-sectional view of the heat-generating
plate 210 (front window 205) taking along a line XIV-XIV
illustrated in FIG. 13.
[0285] The conductor sheet 220 includes a supporting base material
221 and a heat-generating conductor 230 arranged on and supported
by the supporting base material 221. A surface of the supporting
base material 221 on which the heat-generating conductor 230 is
arranged is bonded to the first transparent plate 211 via a first
bonding layer 213, and a surface of the supporting base material
221 opposite to the surface on which the heat-generating conductor
230 is arranged is bonded to the second transparent plate 212 via a
second bonding layer 214. Therefore, in the heat-generating plate
210 in this example, the first transparent plate 211 functions as a
covering member for covering the heat-generating conductor 230, and
the heat-generating conductor 230 is arranged between the
supporting base material 221 and the first transparent plate
211.
[0286] Heat generated by the heat-generating conductor 230 is
transmitted to the first transparent plate 211 via the first
bonding layer 213 and transmitted to the second transparent plate
212 via the supporting base material 221 and the second bonding
layer 214. As a result, the first transparent plate 211 and the
second transparent plate 212 are heated, and frost, ice (snow and
the like), and water attached to the first transparent plate 211
and the second transparent plate 212 are removed, and the fogging
of the first transparent plate 211 and the second transparent plate
212 can be eliminated. By using the heat-generating plate 210 as a
defroster in this way, frost and ice formation and dew condensation
on the front window 205 (particularly, first transparent plate 211
and second transparent plate 212) are prevented so as to keep an
excellent visibility of a vehicle occupant.
[0287] Transparence of the heat-generating plate 210 according to
the present embodiment is not particularly limited as long as the
heat-generating plate 210 is transparent enough so that the
heat-generating plate 210 can be viewed through from one side to
the other side, and it is preferable that the heat-generating plate
210 have a visible light transmittance of, for example, equal to or
higher than 30%, and more preferably, a visible light transmittance
of equal to or higher than 70%. Here, the visible light
transmittance is specified as an average value of transmittances in
respective wavelengths when the transmittance is measured by a
spectrophotometer (for example, "UV-3100PC" manufactured by
SHIMADZU CORPORATION, conforming to JISK0115) within a measurement
wavelength range of 380 nm to 780 nm.
[0288] In a case where the heat-generating plate 210 is used for
the front window 205 as in this example, it is especially required
to secure a clear visibility by using the heat-generating plate
210. Therefore, it is preferable that the first transparent plate
211 and the second transparent plate 212 included in the
heat-generating plate 210 used for the front window 205 have a high
visible light transmittance, for example, a visible light
transmittance of equal to or higher than 90%. As a material of each
of the first transparent plate 211 and the second transparent plate
212, various members can be selected, and for example, a resin
plate and a glass plate can be used. As a resin material forming
the first transparent plate 211 and the second transparent plate
212, acrylic resin polycarbonate such as polymethyl (meth)
acrylate, polybutyl (meth) acrylate, methyl (meth) acrylate-butyl
(meth) acrylate copolymer, and methyl (meth) acrylate-styrene
copolymer can be exemplified. The term of "(meth) acrylate" used
here means acrylate or methacrylate. The acrylic resin is suitable
for the heat-generating plate 210, and especially, for the
heat-generating plate 210 used for the front window 205 and the
rear window in a point of high durability. In a part or all of the
first transparent plate 211 and the second transparent plate 212, a
visible light transmittance may be deteriorated due to coloring or
the like. For example, to prevent an increase in a temperature in a
vehicle on a sunny summer day by shielding direct sunlight or to
make it difficult to visually recognize an interior of the vehicle
from outside the vehicle, a part or all of the first transparent
plate 211 and the second transparent plate 212 may have a
relatively low visible light transmittance.
[0289] To secure high strength and excellent optical
characteristics, it is preferable that the first transparent plate
211 and the second transparent plate 212 have a thickness of equal
to or more than 2 mm and equal to or less than 20 mm. In addition,
the first transparent plate 211 and the second transparent plate
212 may be formed of the same materials, may have the same
structures, and at least one of the materials or structures of the
first transparent plate 211 and the second transparent plate 212
may be different from each other. Furthermore, although the first
transparent plate 211 and the second transparent plate 212 have
substantially the same planar shape and size, the first transparent
plate 211 and the second transparent plate 212 may have different
planar shapes and sizes as necessary.
[0290] The "first bonding layer 213" for bonding the first
transparent plate 211 to the conductor sheet 220 (supporting base
material 221) and the "second bonding layer 214" for bonding the
second transparent plate 212 and the conductor sheet 220
(supporting base material 221) are formed of materials having
various adhesiveness and viscosity and can be formed in layers.
From the viewpoint of securing a clear field of view, it is
preferable that the first bonding layer 213 and the second bonding
layer 214 be formed of a material with a high visible light
transmittance, and typically, formed of polyvinyl butyral (PVB).
The thickness of each of the first bonding layer 213 and the second
bonding layer 214 is preferably equal to or more than 0.15 mm and
equal to or less than 1 mm. In addition, the first bonding layer
213 and the second bonding layer 214 may be formed of the same
materials, may have the same structures, and at least one of the
materials or structures of the first bonding layer 213 and the
second bonding layer 214 may be different from each other.
[0291] The transparent heat-generating plate 210 is not limited to
the illustrated example, and other function layer that is expected
to perform a specific function may be provided, for example, in
addition to the above structure. Furthermore, each component of the
heat-generating plate 210 may perform two or more functions, and
for example, a function other than the above-described functions
may be further added to at least one component of the first
transparent plate 211, the second transparent plate 212, the first
bonding layer 213, the second bonding layer 214, and the conductor
sheet 220 (heat-generating conductor 230 and supporting base
material 221). For example, a member or structure that provides at
least one of an Anti-Reflection (AR) function, a Hard Coating (HC)
function having scratch resistance, an infrared ray shielding
(reflection) function, an ultraviolet ray shielding (reflection)
function, an antifouling function, and other functions may be added
to each component of the heat-generating plate 210.
[0292] <Conductor Sheet 220>
[0293] The conductor sheet 220 in this example includes the pair of
bus bars 225 and the heat-generating conductor 230 as described
above, has substantially the same planar shape and size as the
first transparent plate 211 and the second transparent plate 212,
and is arranged over the entire first transparent plate 211 and the
entire second transparent plate 212 (heat-generating plate 210).
However, the planar shape and the size of the conductor sheet 220
are not particularly limited, and the conductor sheet 220 may be
smaller than the first transparent plate 211 and the second
transparent plate 212. For example, the conductor sheet 220 may be
provided on a part of the heat-generating plate 210 (first
transparent plate 211 and second transparent plate 212) so that the
conductor sheet 220 cover a specific area such as a front portion
of a driver's seat.
[0294] A material of the supporting base material 221 of the
conductor sheet 220 is not particularly limited if the supporting
base material 221 can appropriately support the heat-generating
conductor 230, and the material preferably has a high visible light
transmittance in the viewpoint of securing a clear field of view.
Therefore, a transparent electrically insulating film which can
transmit light with wavelengths in a visible light wavelength range
(for example, 380 nm to 780 nm) can be preferably used as the
supporting base material 221. For example, the supporting base
material 221 can be formed of a polyester resin such as
polyethylene terephthalate, polyethylene naphthalate, polybutylene
terephthalate, and ethylene-terephthalate-isophthalate copolymer.
To appropriately support the heat-generating conductor 230 while
keeping sufficient light transmittance, it is preferable that the
supporting base material 221 have the thickness of equal to or more
than 0.03 mm and equal to or less than 0.15 mm.
[0295] On the other hand, a material of the heat-generating
conductor 230 is not particularly limited as long as the material
can be heated by being energized. For example, the heat-generating
conductor 230 can be formed of gold, silver, copper, platinum,
aluminum, chromium, molybdenum, nickel, titanium, palladium,
indium, tungsten, or an alloy thereof. The heat-generating
conductor 230 may be formed of an opaque metal material. However,
in a case where the heat-generating conductor 230 is formed of an
opaque material or a material with low transparence, it is
preferable to sufficiently thin the heat-generating conductor 230
so as not to excessively shield a field of view of a user.
[0296] Therefore, it is preferable that a proportion (that is,
uncoating ratio) of a region that is not covered with the
heat-generating conductor 230 of a planar area of the supporting
base material 221 be set to high, for example, equal to or higher
than 70% and equal to or lower than 98%. Furthermore, it is
preferable that a line width of the conductive thin wire
(conductive main thin wire 231 or conductive sub thin wire 232 to
be described later) included in the heat-generating conductor 230
be about equal to or more than 2 .mu.m and equal to or less than 20
.mu.m. Specifically, regarding the sizes of the conductive thin
wire, it is preferable that the width W in a direction along the
plate surface of the transparent heat-generating plate 210 be about
equal to or more than 2 .mu.m and equal to or less than 20 .mu.m,
and it is preferable that the height (thickness) H in a normal
direction of the plate surface of the transparent heat-generating
plate 210 be equal to or more than 1 .mu.m and equal to or less
than 20 .mu.m. If the heat-generating conductor 230 (conductive
thin wire) has the width W and the height H as described above, the
heat-generating conductor 230 is sufficiently thin and can be
visually inconspicuous. By providing the heat-generating conductor
230 based on the uncoating ratio and the line width, the entire
region where the heat-generating conductor 230 is provided has high
transparence, and the heat-generating conductor 230 does not
excessively impair visually transmitting performance of the
transparent heat-generating plate 210.
[0297] As described above, the heat-generating conductor 230 is
formed on the supporting base material 221 so as to increase the
uncoating ratio, and the first bonding layer 213 has contact with
the heat-generating conductor 230 and has contact with a portion
(non-coated portion) of the supporting base material 221 that is
not covered with the heat-generating conductor 230. Therefore, in
the heat-generating plate 210 in this example, the heat-generating
conductor 230 is embedded in the first bonding layer 213.
[0298] Regarding the heat-generating conductor 230, a surface
portion may have a dark color layer (refer to "first dark color
layer 237" and "second dark color layer 238" illustrated in FIG. 25
and the like to be described later), and at least a part of an
energized portion at the center of the heat-generating conductor
230 (refer to "conductive layer 236" illustrated in FIG. 25 and the
like) may be covered with the dark color layer. Depending on the
material, the heat-generating conductor 230 may have a relatively
high light reflectance, and there is a case where light reflected
by the heat-generating conductor 230 is visually conspicuous. The
light reflected by the heat-generating conductor 230 interferes the
field of view of a vehicle occupant in a vehicle and deteriorates
design by allowing the visual recognition of the heat-generating
conductor 230 from the outside of the vehicle. Therefore, by
forming a dark color layer such as black layer having lower visual
light reflectance than that of the energized portion at the center
of the heat-generating conductor 230 on the surface of the
heat-generating conductor 230, reflection of light by the
heat-generating conductor 230 can be prevented, and the
deterioration in design can be prevented while securing an
excellent field of view of a vehicle occupant.
[0299] Next, a wiring pattern of the heat-generating conductor 230
according to the present embodiment will be described.
[0300] FIG. 15 is an enlarged plan view illustrating an exemplary
wiring pattern of the heat-generating conductor 230. In FIG. 15,
for convenience of explanation, of the heat-generating plate 210,
only the heat-generating conductor 230 and the supporting base
material 221 are illustrated.
[0301] The heat-generating conductor 230 according to the present
embodiment includes a plurality of conductive main thin wires 231
and conductive sub thin wires 232 for coupling the conductive main
thin wires 231 arranged adjacent to each other. Each conductive
main thin wire 231 extends in a direction from one bus bar 225
toward the other bus bar 225 (refer to Y direction in FIG. 15)
between the pair of bus bars 225 (refer to FIG. 13) and are
connected to the bus bars 225. Each conductive main thin wire 231
is curved in an irregular wavy shape and arranged on the supporting
base material 221, and the conductive main thin wire 231 has a
plurality of curved portions having different curvatures (that is,
curved degree) from each other. In addition, the conductive main
thin wires 231 have different wave shapes from each other.
[0302] The conductive sub thin wire 232 is provided on at least a
part of the plurality of conductive main thin wires 231 and is
discretely arranged. That is, the plurality of conductive sub thin
wires 232 is arranged in the present embodiment, and the conductive
sub thin wires 232 are arranged at positions different from each
other along the direction from one of the bus bars 225 to the other
bus bar 225 (refer to Y direction in FIG. 15). Each conductive sub
thin wire 232 has an irregular wavy shape including a plurality of
curved portions having different curvatures (that is, curved
degree) from each other. In addition, the conductive sub thin wires
232 have different wave shapes from each other. The conductive sub
thin wire 232 and the conductive main thin wire 231 have the same
composition and are continuously and integrally formed.
[0303] As described above, each of the conductive main thin wires
231 and the conductive sub thin wires 232 included in the
heat-generating conductor 230 has curved portions with various
curvatures. In particular, the conductive main thin wire 231
according to the present embodiment includes a "portion with a
relatively small curvature (first small curvature portion, refer to
reference numeral "231a" in FIG. 15)" and a "portion with a
relatively large curvature (first large curvature portion, refer to
reference numeral "231b" in FIG. 15)" of which cross sectional
areas have different inclinations. That is, the inclination of the
cross section of the first large curvature portion with a
relatively large curvature of the cross section of the conductive
main thin wire 231 is larger than that of the first small curvature
portion with a relatively small curvature.
[0304] FIG. 16A is an enlarged view of a portion (first small
curvature portion) indicated by the reference numeral "231a" in
FIG. 15, and FIG. 16B is an enlarged view of a portion (first large
curvature portion) indicated by the reference numeral "231b" in
FIG. 15. FIG. 17A is a cross-sectional view taken along a line
XVIIA-XVIIA in FIG. 16A, and FIG. 17B is a cross-sectional view
taken along a line XVIIB-XVIIB in FIG. 16B.
[0305] A cross section of the heat-generating conductor 230
(conductive main thin wire 231 and conductive sub thin wire 232)
according to the present embodiment is divided by a lower bottom S3
having contact with the supporting base material 221, an upper
bottom S1 arranged at a position facing to the lower bottom S3, a
first inclined portion S2 extending between one end E2 of the lower
bottom S3 and one end E1 of the upper bottom S1, and a second
inclined portion S4 extending between the other end E4 of the lower
bottom S3 and the other end E3 of the upper bottom S1 (refer to
FIGS. 17A and 17B). In addition, the cross sectional area of the
heat-generating conductor 230 (conductive main thin wire 231 and
conductive sub thin wire 232) according to the present embodiment
is substantially symmetrically formed with an axis passing through
the center of the upper bottom S1 and the center of the lower
bottom S3.
[0306] An inclination of the cross sectional area of the
heat-generating conductor 230 (conductive main thin wire 231 and
conductive sub thin wire 232) is expressed by each of an
inclination of a straight line passing through the one end E2 of
the lower bottom S3 and the one end E1 of the upper bottom S1 and
an inclination of a straight line passing through the other end E4
of the lower bottom S3 and the other end E3 of the upper bottom
S1.
[0307] As described above, in the conductive main thin wire 231
according to the present embodiment, the inclination of the cross
sectional area of a large curvature portion (first large curvature
portion) 31b with a relatively large curvature is larger than the
inclination of the cross sectional area of a small curvature
portion (first small curvature portion) 31a with a relatively small
curvature. Therefore, an "inclination angle .theta.1" formed by
each of a "straight line T1 passing through the one end E2 of the
lower bottom S3 and the one end E1 of the upper bottom S1" and a
"straight line T1 passing through the other end E4 of the lower
bottom S3 and the other end E3 of the upper bottom S1" of the small
curvature portion 231a illustrated in FIG. 17A and the lower bottom
S3 and an "inclination angle .theta.2" formed by a "straight line
T2 passing through the one end E2 of the lower bottom S3 and the
one end E1 of the upper bottom S1" and a "straight line T2 passing
through the other end E4 of the lower bottom S3 and the other end
E3 of the upper bottom S1" of the large curvature portion 231b
illustrated in FIG. 17B and the lower bottom S3 satisfy the
following relational expression 1.
.theta.1<.theta.2 <Relational Expression 1>
[0308] In addition, the heights of the cross sectional areas of the
heat-generating conductors 230 (conductive main thin wire 231 and
conductive sub thin wire 232) are almost the same. That is, an
interval H1 between the upper bottom S1 and the lower bottom S3 of
the cross sectional area of the small curvature portion 231a
illustrated in FIG. 17A is equal to an interval H2 between the
upper bottom S1 and the lower bottom S3 of the cross sectional area
of the large curvature portion 231b illustrated in FIG. 17B, and
the following relational expression 2 is satisfied.
H1=H2 <Relational Expression 2>
[0309] A projection size P1 (refer to FIG. 17A) of the cross
sectional area of the small curvature portion 231a on the
supporting base material 221 is larger than a projection size P2
(refer to FIG. 17B) of the cross sectional area of the large
curvature portion 231b on the supporting base material 221, and the
following relational expression 3 is satisfied. That is, along the
direction along a supporting surface of the supporting base
material 221 (refer to X direction in FIGS. 17A and 17B), the
"length of the entire cross sectional area (particularly, lower
bottom S3 in the present embodiment) of the small curvature portion
231a" is longer than the "length of the entire cross sectional area
(particularly, lower bottom S3 in the present embodiment) of the
large curvature portion 231b".
P1>P2 <Relational Expression 3>
[0310] Furthermore, the sum of a "projection size P3a of the first
inclined portion S2" and a "projection size P3b of the second
inclined portion S4" of the cross sectional area of the small
curvature portion 231a on the supporting base material 221 is
larger than the sum of a "projection size P4a of the first inclined
portion S2" and a "projection size P4b of the second inclined
portion S4" of the cross sectional area of the large curvature
portion 231b on the supporting base material 221, and the following
relational expression 4 is satisfied. That is, along the direction
along the supporting surface of the supporting base material 221,
the "sum of the lengths of the first inclined portion S2 and the
second inclined portion S4 of the cross sectional area of the small
curvature portion 231a" is larger than the "sum of the lengths of
the first inclined portion S2 and the second inclined portion S4 of
the cross sectional area of the large curvature portion 231b".
(P3a+P3b)>(P4a+P4b) <Relational Expression 4>
[0311] A projection size W1 of the upper bottom S1 of the cross
sectional area of the small curvature portion 231a on the
supporting base material 221 is larger than a projection size W2 of
the upper bottom S1 of the cross sectional area of the large
curvature portion 231b on the supporting base material 221.
[0312] An area of the cross sectional area of the small curvature
portion 231a is larger than an area of the cross sectional area of
the large curvature portion 231b.
[0313] As described above, according to the present embodiment, the
shape and the size of the cross sectional area of each conductive
thin wire (conductive main thin wire 231) is determined according
to the curvature of the wire of the heat-generating conductor 230
(conductive thin wire), and generation of a beam of light and
generation of glare can be prevented at a high level. That is, by
forming the conductive main thin wire 231 with "a plurality of
conductive thin wires irregularly arranged with various
curvatures", generation of a beam of light that can be visually
recognized can be effectively prevented. Furthermore, by inclining
the cross sectional area of the conductive main thin wire 231 with
various angles (refer to ".theta.1" in FIG. 17A and ".theta.2" in
FIG. 17B), glare such as dazzle and blur can be effectively
prevented. Then, "by setting the inclination of the cross sectional
area of the large curvature portion (large curvature portion 231b)
of the cross sectional area of the conductive main thin wire 231 to
be larger than the inclination of the cross sectional area of the
small curvature portion (small curvature portion 231a)", "the
prevention of generation of a beam of light" and "antiglare" can be
achieved at a high level while avoiding disconnection of the
conductive main thin wire 231.
[0314] The configuration of the conductive main thin wire 231 is
effective for the conductive sub thin wire 232 (refer to FIG. 15),
and it is preferable for the cross sectional area of the conductive
sub thin wire 232 to similarly satisfy the relationship regarding
the cross sectional area of the conductive main thin wire 231.
Therefore, "the conductive sub thin wire 232 includes a plurality
of conductive thin wires irregularly arranged as having various
curvatures", "the conductive sub thin wire 232 includes a curved
portion with a relatively large curvature (second large curvature
portion) and a curved portion with a relatively small curvature
(second small curvature portion)", "the cross sectional areas of
the conductive sub thin wire 232 have inclinations with various
angles", and "the inclination of the cross sectional area of the
large curvature portion (second large curvature portion) of the
cross sectional area of the conductive sub thin wire 232 is set to
be larger than the inclination of the cross sectional area of the
small curvature portion (second small curvature portion) so that
"the prevention of generation of a beam of light" and "antiglare"
can be achieved at a high level while avoiding disconnection of the
conductive sub thin wire 232.
[0315] In addition, the structure of the heat-generating plate 210
is not limited to that illustrated in FIG. 14, and other layers may
be added, and elements other than the heat-generating conductor 230
may be omitted. For example, as illustrated in FIG. 18, the first
transparent plate 211 is directly laminated on the surface of the
supporting base material 221 on which the heat-generating conductor
230 is provided so as to cover the heat-generating conductor 230,
and the first transparent plate 211, the heat-generating conductor
230, and the supporting base material 221 may form the
heat-generating plate 210. In addition, other function layer may be
appropriately added to the heat-generating conductor 230
illustrated in FIG. 18.
[0316] <Manufacturing Method for Heat-Generating Plate
210>
[0317] Next, a manufacturing method for the heat-generating plate
210 will be described. The manufacturing method for the
heat-generating plate 210 is not particularly limited. However, as
an example, a method of forming a conductive thin wire (conductive
main thin wire 231 and conductive sub thin wire 232) including a
conductive layer and a dark color layer on the supporting base
material 221 will be described below. In the following description,
an example of a manufacturing method for the heat-generating plate
210 illustrated in FIG. 18 will be described. However, the
heat-generating plate 210 having other structure (refer to FIG. 14)
can be manufactured by appropriately applying the following
manufacturing method.
[0318] FIGS. 19 to 25 are cross-sectional views for explaining an
example of the manufacturing method for the heat-generating plate
210, and processes for manufacturing the heat-generating plate 210
will be sequentially described.
[0319] First, as illustrated in FIG. 19, a dark color film 237a to
be a first dark color layer of the heat-generating conductor 230
(conductive main thin wire 231 and conductive sub thin wire 232) is
laminated on a copper foil film 236a which is a member to be a
conductive layer of the heat-generating conductor 230 (conductive
main thin wire 231 and conductive sub thin wire 232). A method for
forming the copper foil film 236a is not particularly limited, and
the copper foil film 236a can be formed by a known method. For
example, the copper foil film 236a may be formed by one of or a
combination of two or more of a plating method including
electroplating and electroless plating, a sputtering method, a CVD
method, a PVD method, and an ion plating method. A method for
forming the dark color film 237a is not particularly limited, and
the dark color film 237a can be formed by a known method. For
example, the dark color film 237a can be formed on the copper foil
film 236a by one of or a combination of two or more of a plating
method including electroplating and electroless plating, a
sputtering method, a CVD method, a PVD method, and an ion plating
method. The dark color film 237a can be formed of various known
materials and may be formed of, for example, copper nitride, copper
oxide, or nickel nitride.
[0320] Next, as illustrated in FIG. 20, a transparent supporting
base material 221 is laminated on a surface opposite to the surface
of the dark color film 237a on which the copper foil film 236a is
laminated. The supporting base material 221 and the dark color film
237a may be surely bonded to each other by providing a bonding
layer including an adhesive agent and an adhesive between the
supporting base material 221 and the dark color film 237a. The
supporting base material 221 may be formed of any member as long as
the supporting base material 221 can appropriately support the
heat-generating conductor 230, and for example, a biaxially
stretched polyester resin such as polyethylene terephthalate and
polyethylene naphthalate can be exemplified as a material of the
supporting base material 221. However, in consideration of
retention of the heat-generating conductor 230 and the like, it is
preferable that the thickness of the supporting base material 221
be equal to or more than 30 .mu.m and equal to or less than 150
.mu.m.
[0321] Next, as illustrated in FIG. 21, a resist pattern 239 is
provided on a surface of the copper foil film 236a opposite to the
surface on which the dark color film 237a is laminated. The resist
pattern 239 is arranged on the copper foil film 236a so as to
finally have a shape corresponding to a wiring pattern (wiring
shape) of the heat-generating conductor 230 to be formed on the
supporting base material 221. That is, the resist pattern 239 is
provided only on a portion of the copper foil film 236a that
finally forms the heat-generating conductor 230 (conductive main
thin wire 231 and conductive sub thin wire 232). The resist pattern
239 can be formed by patterning using a known photolithography
technique. For example, in a case of using proximity exposure with
a photomask, when a negative type photoresist is used, a desired
resist pattern 239 can be formed on the copper foil film 236a by
forming a shielding pattern on the photomask and performing
patterning.
[0322] Next, the resist pattern 239 is used as a mask, and the
copper foil film 236a and the dark color film 237a are etched. By
this etching, the copper foil film 236a and the dark color film
237a are patterned to have planar shapes substantially the same as
the resist pattern 239. As a result of the patterning, as
illustrated in FIG. 22, the conductive layer 236 to be a part of
the conductive thin wire (conductive main thin wire 231 and
conductive sub thin wire 232) is formed from the copper foil film
236a, and a first dark color layer 237 to be a part of the
conductive thin wire (conductive main thin wire 231 and conductive
sub thin wire 232) is formed from the dark color film 237a.
[0323] An etching method is not particularly limited, and a known
method can be employed. For example, the copper foil film 236a and
the dark color film 237a can be etched by wet etching using an
etchant such as an aqueous ferric chloride solution or dry etching
such as plasma etching.
[0324] Next, as illustrated in FIG. 23, the resist pattern 239 is
removed by an arbitrary method. Accordingly, the heat-generating
conductor 230 (conductive layer 236 and first dark color layer 237)
wired on the supporting base material 221 in a predetermined
pattern is obtained.
[0325] Next, as illustrated in FIG. 24, a second dark color layer
238 is formed on a surface 235a of the conductive layer 236
opposite to the surface 235b on which the first dark color layer
237 is provided and on side surfaces 35c and 35d of the conductive
layer 236. A method of forming the second dark color layer 238 is
not particularly limited. For example, the dark color layer 238 can
be formed from a part of the material forming the conductive layer
236 by performing darkening processing (blackening processing) on a
part of the conductive layer 236. Since the conductive layer 236
according to the present embodiment is formed of copper (copper
foil film 236a), the second dark color layer 238 formed of, for
example, copper oxide or copper sulfide can be formed as a surface
layer of the conductive layer 236.
[0326] Alternatively, a second dark color layer 238 such as a
coating film of a dark color material, a plating layer of nickel or
chromium, or a sputtered layer of copper oxide (CuO) or copper
nitride may be additionally provided on the surface of the
conductive layer 236. In a case where the second dark color layer
238 is additionally provided, the second dark color layer 238 may
be provided on the conductive layer 236 after at least a part of
the surfaces (surface 235a and side surfaces 235c and 235d) of the
conductive layer 236 is roughened.
[0327] Through the series of processes (refer to FIGS. 19 to 24),
the heat-generating conductor 230 (conductive main thin wire 231
and conductive sub thin wire 232) coated with the conductive layer
236 by the first dark color layer 237 and the second dark color
layer 238 is formed on the supporting base material 221, and the
conductor sheet 220 is produced. In this way, the heat-generating
conductor 230 is formed on the supporting base material 221
separated from the first transparent plate 211 (refer to FIG. 18),
and it is preferable that the supporting base material 221 have an
appropriate thickness as a supporting member at the time when the
heat-generating conductor 230 is formed, and the thickness to apply
rigidity to the heat-generating plate 210 is not required for the
supporting base material 221. Therefore, according to the series of
manufacturing methods illustrated in FIGS. 19 to 24, a large number
of heat-generating conductors 230 used for the plurality of
heat-generating plates 210 can be sequentially formed on a long
supporting base material 221, and the heat-generating conductor 230
can be manufactured at a very low cost than a conventional method
for forming a heat-generating conductor for each heat-generating
plate 210. In addition, according to the manufacturing method
described above, since a part of the pair of bus bars 225 and the
wiring portion 215 illustrated in FIG. 13 can be formed with the
heat-generating conductor 230 by using the same material as the
heat-generating conductor 230, the conductor sheet 220 and the
heat-generating plate 210 can be inexpensively manufactured.
Furthermore, according to the manufacturing method described above,
a part of the pair of bus bars 225 and the wiring portion 215 can
be integrally form with the heat-generating conductor 230 by using
the same material as the heat-generating conductor 230. In this
case, electrical connection from the heat-generating conductor 230
to the wiring portion 215 via the bus bars 225 can be more stably
secured.
[0328] Next, the first transparent plate 211 is laminated on the
surface of the supporting base material 221 on which the
heat-generating conductor 230 (conductive layer 236, first dark
color layer 237, and second dark color layer 238) is provided. FIG.
25 illustrates an example in which the first transparent plate 211
is formed by injection molding and bonded to the supporting base
material 221. In the example illustrated in FIG. 25, the conductor
sheet 220 is arranged in a cavity 241a of a mold 241 for injection
molding. The conductor sheet 220 is arranged in the cavity 241a so
that the surface of the supporting base material 221 on which the
heat-generating conductor 230 is arranged faces inward of the
cavity 241a and a resin supplied from a resin supply port 42 of the
mold 241 to the cavity 241a is laminated on the "surface of the
supporting base material 221 on which the heat-generating conductor
230 is arranged". Then, a resin such as acrylic which is heated and
has fluidity is injected from the resin supply port 42 of the mold
241 to the cavity 241a and laminated on the supporting base
material 221 and the heat-generating conductor 230 (conductive
layer 236, first dark color layer 237, and second dark color layer
238). The resin injected into the cavity 241a is cooled in the
cavity 241a and solidified on the supporting base material 221 and
the heat-generating conductor 230, and finally forms the first
transparent plate 211 to be bonded to the supporting base material
221 and the heat-generating conductor 230. According to the
injection molding described above, even when the first transparent
plate 211 (heat-generating plate 210) has a plate-like shape or
curved plate-like shape, the first transparent plate 211
(heat-generating plate 210) can be easily and inexpensively formed
on the conductor sheet 220 (supporting base material 221 and
heat-generating conductor 230).
[0329] A primer layer to secure adhesiveness may be provided in
advance on a surface of the conductor sheet 220 (supporting base
material 221) on which the heat-generating conductor 230 is formed.
In this case, the primer layer can improve adhesion between the
conductor sheet 220 (supporting base material 221) and the first
transparent plate 211.
[0330] According to the manufacturing method for the
heat-generating plate 210 illustrated in FIGS. 19 to 25, the
heat-generating conductor 230 can be arranged between the first
transparent plate 211 and the supporting base material 221
relatively easily and reliably. In particular, by using the first
transparent plate 211 as a covering member of the heat-generating
conductor 230, it is not necessary to use glass having a large
weight density as a supporting base material of the heat-generating
conductor 230, and the weight of the heat-generating plate 210 can
be largely reduced. In addition, since the heat-generating
conductor 230 is formed on the supporting base material 221 that
functions as a supporting member, the conductor sheet 220 that can
be easily handled can be provided. Therefore, according to the
series of manufacturing methods, based on a photolithography
technique, the conductor sheet 220 can be easily and quickly formed
typically in a role-to-role manner. In this way, according to the
manufacturing method for the heat-generating plate 210 illustrated
in FIGS. 19 to 25, the plurality of heat-generating conductors 230
can be continuously, efficiently and inexpensively manufactured,
and the heat-generating plate 210 of which the weight is finally
reduced can be inexpensively and stably manufactured.
[0331] <Modification>
[0332] The present invention is not limited to the embodiments, and
various changes may be made to the embodiments.
[0333] For example, in the above manufacturing method, as
illustrated in FIG. 25, although the heat-generating plate 210 is
formed in which the supporting base material 221, the
heat-generating conductor 230, and the first transparent plate 211
are sequentially laminated, other layers may be further laminated.
For example, on at least one of "the surface of the first
transparent plate 211 opposite to the surface bonded to the
supporting base material 221" and "the surface of the supporting
base material 221 (conductor sheet 220) opposite to the surface to
be bonded to the first transparent plate 211", the other coating
layer may be laminated.
[0334] FIG. 26 is a cross-sectional view illustrating another
modification of the heat-generating plate 210. In addition of the
supporting base material 221, the heat-generating conductor 230,
and the first transparent plate 211 (refer to FIG. 25), the
heat-generating plate 210 of this example further includes a
transparent coating layer 245 for coating the first transparent
plate 211 from a side opposite to the conductor sheet 220 and a
transparent coating layer 246 for covering the conductor sheet 220
from a side opposite to the first transparent plate 211. The
coating layers 245 and 246 forming a surface layer (outermost
surface) of the heat-generating plate 210 function as a hard
coating layer having scratch resistance and protect the first
transparent plate 211 and the conductor sheet 220 to improve
durability of the heat-generating plate 210. These coating layers
245 and 246 can be formed by using, for example, a known acrylic
ultraviolet curable resin. That is, on each of the first
transparent plate 211 and the conductor sheet 220 (supporting base
material 221), a composition including a monomer of an acrylic
ultraviolet curable resin, a prepolymer, or both of them, and a
photopolymerization initiator is coated in a film-like shape. Then,
by irradiating the coated film with ultraviolet rays and curing the
coated film by crosslinking reaction or polymerization, a cured
resin is obtained. The cured resin layer obtained in this way can
be used as the coating layers 245 and 246 that function as hard
coating layers.
[0335] In the above embodiment (for example, refer to FIG. 25),
although the first transparent plate 211 is laminated on the
conductor sheet 220 (supporting base material 221 and
heat-generating conductor 230) so as to face to the surface of the
conductor sheet 220 on which the heat-generating conductor 230 is
provided, the arranged position of the first transparent plate 211
is not limited to this.
[0336] FIG. 27 is a cross-sectional view illustrating still another
modification of the heat-generating plate 210. In the
heat-generating plate 210 in this example, the first transparent
plate 211 is laminated on the conductor sheet 220 (supporting base
material 221) so as to face to a surface opposite to the surface of
the conductor sheet 220 (supporting base material 221) on which the
heat-generating conductor 230 is provided. In this example, since
the heat-generating conductor 230 is exposed outside without being
coated with the first transparent plate 211, there is a possibility
that an external force such as an impact acts on and disconnects
the heat-generating conductor 230 and the heat-generating conductor
230 rusts due to moisture in the air or the like. Therefore, in a
case where the heat-generating conductor 230 is not coated with the
first transparent plate 211, it is preferable that the
heat-generating conductor 230 is coated with another coating layer
to prevent exposure of the heat-generating conductor 230 to the
outside.
[0337] FIG. 28 is a cross-sectional view illustrating yet another
modification of the heat-generating plate 210. The heat-generating
plate 210 of this example can be obtained by applying the coating
layers 245 and 246 illustrated in FIG. 26 to the heat-generating
plate 210 illustrated in FIG. 27. That is, the coating layer 245 is
provided on the surface of the conductor sheet 220 (supporting base
material 221) on which the heat-generating conductor 230 is
provided, and the heat-generating conductor 230 is coated with the
coating layer 245. With the coating layer 245, the heat-generating
conductor 230 is separated from outside and is protected,
disconnection and rust of the heat-generating conductor 230 can be
prevented. Furthermore, the coating layer 246 is provided on the
surface of the first transparent plate 211 opposite to the surface
on which the supporting base material 221 is provided, and the
first transparent plate 211 is coated with the coating layer 246.
As a result, the first transparent plate 211 is separated from
outside and is protected, and durability of the heat-generating
plate 210 can be improved.
[0338] In addition, at least one of layers of the heat-generating
plate 210 may include ultraviolet ray absorber dispersed therein.
In this case, since the ultraviolet ray absorber absorbs
ultraviolet rays and an amount of ultraviolet rays, entering from
outside, on the inner side of the layer including the ultraviolet
ray absorber is reduced, deterioration such as yellowing caused by
ultraviolet rays caused in a member on the inner side of the layer
including the ultraviolet ray absorber can be effectively
prevented. That is, by including the ultraviolet ray absorber in
the heat-generating plate 210, the light resistance property of the
heat-generating plate 210 can be improved. As an example of the
ultraviolet ray absorber, benzotriazole-based compounds and
benzophenone-based compounds can be exemplified. It is preferable
that a mass ratio of the ultraviolet ray absorber in the layer
including the ultraviolet ray absorber be 0.5 to 5.0 mass %.
[0339] In a case where a coating layer is provided on the
heat-generating plate 210, a moisture permeability of the coating
layer may be lower than that of the supporting base material 221.
By a coating layer with a low moisture permeability, it is possible
to effectively prevent water vapor from reaching the
heat-generating conductor 230 (conductive main thin wire 231 and
conductive sub thin wire 232), and deterioration in the
heat-generating conductor 230 (conductive main thin wire 231 and
conductive sub thin wire 232) due to rust can be prevented.
[0340] The moisture permeability can be measured by a method
specified in JISZ0208.
[0341] Furthermore, the heat-generating plate 210 may have a curved
shape, a plate-like shape, and other shape according to the
application.
[0342] Furthermore, in the above embodiment, an example in which an
acrylic resin is used as a material of the first transparent plate
211 has been described. However, the present invention is not
limited to this example. For example, a polyolefin resin, a
polycarbonate resin, a vinyl chloride resin, or the like may be
used as the material of the first transparent plate 211.
[0343] Furthermore, in the above embodiment, regarding a method for
laminating the first transparent plate 211 and the conductor sheet
220, an example is illustrated in which the first transparent plate
211 and the conductor sheet 220 are laminated and integrated (refer
to FIG. 25) by injection-molding and filling a melt of the resin
forming the first transparent plate 211 into the cavity, after
arranging the conductor sheet 220 in the mold cavity for molding
the first transparent plate 211 in advance. However, the present
invention is not limited to this. For example, the first
transparent plate 211 and the conductor sheet 220 may be laminated
and integrated by preparing the previously molded first transparent
plate 211 and bonding the conductor sheet 220 on one of the
surfaces of the first transparent plate 211 via an adhesive layer.
As a specific example, the heat-generating plate 210 illustrated in
FIG. 24 can be produced by heating and pressurizing the first
transparent plate 211 and the second transparent plate 212 to bond
these plates to the conductor sheet 220 via the first bonding layer
213 and the second bonding layer 214 formed of polyvinyl butyral
(PVB).
[0344] The heat-generating plate 210 may be used not only for a
window of the automobile 201 but also for windows and doors of
vehicles other than the automobile 201 (for example, train,
aircraft, ship and spacecraft).
[0345] In addition, the heat-generating plate 210 can be applied to
anything other than the vehicles and can be appropriately used for
a "place for dividing a space (for example, indoor and outdoor)"
such as windows for buildings such as shops and houses.
[0346] Furthermore, the embodiments and the modifications may be
appropriately combined.
Fourth Embodiment
[0347] In the present specification, terms of "plate", "sheet", and
"film" are not distinguished from each other only based on a
difference in the name. For example, "a sheet with a conductor" is
a concept including a member which can be called as plate and film.
Therefore, the "sheet with a conductor" is not distinguished from
members called as "a plate (substrate) with a conductor" and "a
film with a conductor" only based on only the difference in the
name. The "conductive pattern sheet" is not distinguished from a
member called as a "conductive pattern plate (substrate)" and a
"conductive pattern film" only based on the difference in the
name.
[0348] In addition, in the present specification, a "sheet surface
(plate surface and film surface)" indicates a surface that
coincides with a planar direction of a sheet-like member to be a
target (plate-like member and film-like member) in a case where an
entire sheet-like member to be a target (plate-like and film-like)
is viewed from a large perspective. Furthermore, a normal direction
relative to a sheet-like member (plate-like and film-like)
indicates a normal direction along a sheet surface (film surface
and plate surface) of the sheet-like (plate-like and film-like)
member.
[0349] In addition, terms used herein for specifying shapes and
geometrical conditions and degrees thereof, for example, terms of
"parallel", "perpendicular", "same" and values of lengths and
angles are not limited to strict meanings and are interpreted as a
including a range of terms that can be expected to have a similar
function.
[0350] FIGS. 29 to 43 are views for explaining one embodiment of
the present invention. FIG. 29 is a view schematically illustrating
an automobile including a heat-generating plate, FIG. 30 is a view
of the heat-generating plate viewed from the normal direction of
the plate surface, and FIG. 31 is a cross-sectional view of the
heat-generating plate in FIG. 30.
[0351] As illustrated in FIG. 29, an automobile 301 as an example
of a vehicle includes a window glass such as a front window, a rear
window, and a side window. Here, an example in which a front window
305 is configured by a heat-generating plate 310 will be described.
In addition, the automobile 301 includes a power supply 307 such as
a battery.
[0352] As illustrated in FIGS. 30 and 31, the heat-generating plate
310 according to the present embodiment includes a pair of glasses
311 and 312, a sheet with a conductor 320 arranged between the pair
of glasses 311 and 312, and a pair of bonding layers 313 and 314
for bonding the respective glasses 311 and 312 to the sheet with a
conductor 320. In the examples illustrated in FIGS. 29 and 30, the
heat-generating plate 310 and the glasses 311 and 312 are curved.
However, in other drawings, for easy understanding, the
heat-generating plate 310 and the glasses 311 and 312 having
plate-like shapes are illustrated.
[0353] The sheet with a conductor 320 includes a base film 321, a
bus bar 325, and a heat-generating conductor 330 provided on a
surface of the base film 321 facing to the glass 311 and including
a conductive thin wire 331.
[0354] As illustrated in FIG. 30, the heat-generating plate 310
includes a wiring portion 315 for energizing the heat-generating
conductor 330 of the sheet with a conductor 320 via the bus bar
325. In the illustrated example, the power supply 307 such as a
battery supplies power to the heat-generating conductor 330 via the
wiring portion 315 and the bus bar 325, and the conductive thin
wire 331 of the heat-generating conductor 330 are heated by
resistance heating. Heat generated by the heat-generating conductor
330 is transmitted to the glasses 311 and 312 and heat the glasses
311 and 312. As a result, fogging due to dew condensation attached
on the glasses 311 and 312 can be removed. In a case where snow or
ice is attached on the glasses 311 and 312, snow and ice can be
melted. Therefore, a passenger's visibility is preferably
secured.
[0355] Each component of the heat-generating plate 310 will be
described below.
[0356] First, the glasses 311 and 312 will be described. When the
glasses 311 and 312 are used for a front window of an automobile as
in the example illustrated in FIG. 29, it is preferable to use a
glass with a high visible light transmittance so as not to
interfere the field of view of a passenger. As a material of the
glasses 311 and 312, soda-lime glass and blue plate glass can be
used. It is preferable that a transmittance of the glasses 311 and
312 in a visible light region be equal to or higher than 90%. Here,
the visible light transmittance of the glasses 311 and 312 are
specified as an average value of transmittances in respective
wavelength when the transmittance is measured by a
spectrophotometer ("UV-3100PC" manufactured by SHIMADZU
CORPORATION, conforming to JIS K 0115) within a measurement
wavelength range of 380 nm to 780 nm. The visible light
transmittance may be lowered by coloring a part of or all of the
glasses 311 and 312. In this case, direct sunlight can be shielded,
and it is possible to make it difficult to visually recognize an
interior of the vehicle from the outside of the vehicle.
[0357] Furthermore, it is preferable that the glasses 311 and 312
have a thickness of equal to or more than 1 mm and equal to or less
than 5 mm. With such a thickness, the glasses 311 and 312 having
excellent strength and optical characteristics can be obtained. The
pair of glasses 311 and 312 may be formed of the same material and
with the same structure, or at least one of the material and the
structure may be different.
[0358] Next, the bonding layers 313 and 314 will be described. The
first bonding layer 313 is arranged between the first glass 311 and
the sheet with a conductor 320 and bonds the glass 311 to the sheet
with a conductor 320. The second bonding layer 314 is arranged
between the second glass 312 and the sheet with a conductor 320 and
bonds the glass 312 to the sheet with a conductor 320.
[0359] As such bonding layers 313 and 314, a layer formed of a
material having various adhesiveness and viscosity can be used.
Furthermore, it is preferable to use a material having a high
visible light transmittance for the bonding layers 313 and 314.
[0360] As a typical bonding layer, a layer formed of polyvinyl
butyral (PVB) can be exemplified. It is preferable that the
thickness of each of the bonding layers 313 and 314 be equal to or
more than 0.15 mm and equal to or less than 1 mm. The pair of
bonding layers 313 and 314 may be formed of the same material and
with the same structure, or at least one of the material and the
structure may be different.
[0361] The heat-generating plate 310 is not limited to the
illustrated example, and other function layer that is expected to
perform a specific function may be provided. Furthermore, one
function layer may perform two or more functions, and for example,
some function may be added to at least one of the glasses 311 and
312 of the heat-generating plate 310, the bonding layers 313 and
314, and the base film 321 of the sheet with a conductor 320 to be
described later. As an example of the function that can be applied
to the heat-generating plate 310, an anti-reflection (AR) function,
a hard coating (HC) function having scratch resistance, an infrared
ray shielding (reflection) function, an ultraviolet ray shielding
(reflection) function, and an antifouling function can be
exemplified.
[0362] Next, the sheet with a conductor 320 will be described. The
sheet with a conductor 320 includes a base film 321, a bus bar 325,
and a heat-generating conductor 330 provided on a surface of the
base film 321 facing to the glass 311 and including a conductive
thin wire 331. The sheet with a conductor 320 may have
substantially the same planer dimensions as the glasses 311 and 312
and be arranged across the entire heat-generating plate 310 and may
be arranged on a part of the heat-generating plate 310 such as a
front portion of a driver's seat in the example in FIG. 29.
[0363] The base film 321 functions as a base material for
supporting the heat-generating conductor 330. The base film 321 is
a so-called transparent electrically insulating substrate for
transmitting light with a wavelength in a visible light wavelength
band (380 nm to 780 nm). As the base film 321, any material can be
used as long as the material can transmit visible light and
appropriately support the heat-generating conductor 330. For
example, polyethylene terephthalate, polyethylene naphthalate,
polycarbonate, polystyrene, and cyclic polyolefine can be
exemplified. In consideration of light transmittance and
appropriate supporting property of the heat-generating conductor
330, it is preferable that the thickness of the base film 321 be
equal to or more than 0.03 mm and equal to or less than 0.20
mm.
[0364] Next, the heat-generating conductor 330 will be described
with reference to FIG. 32. FIG. 32 is a plan view illustrating the
heat-generating conductor 330 from the normal direction of the
sheet surface. FIG. 32 is a view illustrating an exemplary
arrangement of the heat-generating conductor 330.
[0365] As illustrated in FIG. 32, the heat-generating conductor 330
includes a plurality of linear conductive thin wires 331 for
coupling the pair of bus bars 325. The conductive thin wire 331 is
energized from the power supply 307 such as a battery via the
wiring portion 315 and the bus bars 325 and generates heat by
resistance heating. Then, the heat is transmitted to the glasses
311 and 312 via the bonding layers 313 and 314 so as to heat the
glasses 311 and 312.
[0366] In the example illustrated in FIG. 32, the plurality of
conductive thin wires 331 extends from one of the bus bars 325 to
the other bus bar 325. The plurality of conductive thin wires 331
is arranged separated from each other. In particular, the plurality
of conductive thin wires 331 is arranged along a direction
perpendicular to the extending direction of the conductive thin
wires 331. A gap 335 is formed between two adjacent conductive thin
wires 331.
[0367] As a material forming the heat-generating conductor 330, for
example, one or more alloys of two or more kinds of metals selected
from among metals including gold, silver, copper, platinum,
aluminum, chromium, molybdenum, nickel, titanium, palladium,
indium, and tungsten and nickel-chromium alloy, and bronze can be
exemplified.
[0368] The heat-generating conductor 330 may be formed by using an
opaque metal material as described above. On the other hand, the
conductive thin wire 331 of the heat-generating conductor 330 is
formed with a high uncoating ratio of about equal to or higher than
70% and equal to or lower than 99.8%. Therefore, an entire region,
in which the conductive thin wire 331 and the coupling conductive
thin wire 332 of the heat-generating conductor 330 are formed, is
transparent and does not impair visibility.
[0369] In the example illustrated in FIG. 31, the conductive thin
wire 331 has a substantially trapezoidal cross section as a whole.
More precisely, the side surface of the conductive thin wire 331
has a concave curved shape to be etched in a manufacturing process
to be described later. It is preferable that a width W of a bottom
portion of the conductive thin wire 331, that is, a length along
the plate surface of the heat-generating plate 310 be equal to or
longer than 11 .mu.m and equal to or shorter than 20 .mu.m and a
height (thickness) H, that is, a height (thickness) along a normal
direction to the plate surface of the heat-generating plate 310 be
equal to or more than 1 .mu.m and equal to or less than 60 .mu.m.
According to the conductive thin wire 331 having such a size, since
the conductive thin wire 331 is sufficiently thinned, the
heat-generating conductor 330 can be effectively made
invisible.
[0370] As illustrated in FIG. 31, the conductive thin wire 331
includes a conductive metal layer 336, a first dark color layer 337
that covers the surface of the conductive metal layer 336 facing to
the base film 321, and a second dark color layer 338 that covers
the surface of the conductive metal layer 336 facing to the glass
311 and side surfaces.
[0371] The conductive metal layer 336 formed of a metal material
having excellent conductivity has a relatively high reflectance.
When the conductive metal layer 336 forming the conductive thin
wire 331 of the heat-generating conductor 330 reflects light, the
reflected light is visually recognized, and the light may interfere
a field of view of a passenger. Furthermore, when the conductive
metal layer 336 is visually recognized from outside, design may be
deteriorated. Thus, the first and second dark color layers 337 and
338 are arranged on at least a part of the surface of the
conductive metal layer 336. It is preferable that the first and
second dark color layers 337 and 338 be having lower reflectance of
visible light than the conductive metal layer 336, for example, the
first and second dark color layers 337 and 338 are layers of dark
colors such as black. With the dark color layers 337 and 338, the
conductive metal layer 336 is hardly and visually recognized, and a
passenger's visibility is preferably secured. In addition, the
deterioration in the design when the viewed from outside can be
prevented.
[0372] As described above, the conductive thin wire 331 of the
heat-generating conductor 330 is formed on the base film 321 with a
high uncoating ratio from viewpoint of securing visually
transmitting performance and visibility. Therefore, as illustrated
in FIG. 31, the bonding layer 313 has contact with the base film
321 of the sheet with a conductor 320 via a non-covered portion of
the conductive thin wire 331, that is, a region between the
adjacent conductive thin wires 331. Therefore, the heat-generating
conductor 330 is embedded in the bonding layer 313.
[0373] Incidentally, in FIG. 33, an enlarged view of a part of the
conductive thin wire 331 viewed from the normal direction of the
sheet surface is illustrated. As a result of intensive
investigation by the inventors of the present invention, as
illustrated in FIG. 33, conductive thin wires 331 of a
heat-generating conductor 330 that have been actually produced are
distributed in a line width W along the longitudinal direction.
Such a tendency has remarkably occurred in the heat-generating
conductor 330 of the sheet with a conductor 320 produced by a
manufacturing method to be described later with reference to FIGS.
35 to 43. When the inventors of the present invention have examined
a relationship between a fluctuation of the line width W and
disconnection of the conductive thin wire 331, it has been
confirmed that the fluctuation of the line width W strongly affects
on how easily the conductive thin wire 331 is disconnected. As a
result of confirmation by the inventors of the present invention,
when it is assumed that an average of the width W of the conductive
thin wire 331 be W.sub.ave and a standard deviation be a, in a case
where the width W is distributed so as to satisfy the following
formula (a), the width of the conductive thin wire 331 can be set
within a range in which the conductive thin wire 331 of the
heat-generating conductor 330 is hardly disconnected and the
conductive thin wire 331 is not visually recognized.
0.ltoreq.4.sigma./W.sub.ave.ltoreq.0.3 Formula (a)
[0374] FIG. 34 is an enlarged view of the conductive thin wire 331
on the sheet with a conductor 320 viewed from the cross sectional
area. In FIG. 34, the conductive metal layer and the dark color
layers are omitted. The conductive thin wire 331 illustrated in
FIG. 34 indicates the cross section of the conductive thin wire 331
produced by a manufacturing method to be described later. In the
example illustrated in FIG. 34, the width W of the conductive thin
wire 331 different at each position along the normal direction of
the sheet with a conductor 320. In the example illustrated in FIG.
34, the width W of the conductive thin wire 331 is different at
each position along the normal direction of the sheet with a
conductor 320. In the conductive thin wire 331 of which the width W
fluctuates along the normal direction of the sheet with a conductor
320, the width W of the conductive thin wire 331 indicates the
maximum width of each cross section that easily affects the
disconnection and visualization. That is, in the example
illustrated in FIG. 34, the width W of the conductive thin wire 331
indicates a width of a bottom portion closest to the base film
321.
[0375] Furthermore, as illustrated in FIG. 33, the conductive thin
wire 331 has a curved line portion, and not only the width of the
curved portion but also a curvature is not constant. In particular,
in the illustrated example, the conductive thin wire 331 is formed
by only curved line portions. Since the conductive thin wire 331
has the curved line portions, generation of a strong streaky light
in a specific direction caused by diffraction in the conductive
thin wire 331, that is, a beam of light can be effectively made
inconspicuous.
[0376] As illustrated in FIG. 33, the curvature of the curved line
portion of the conductive thin wire 331 is not constant.
Especially, the conductive thin wire 331 includes a "portion with a
relatively small curvature (small curvature portion, refer to
reference numeral "A" in FIG. 33)" and a "portion with a relatively
large curvature (first large curvature portion, refer to reference
numeral "B" in FIG. 33)" of which respective widths W of the
conductive thin wire 331 are different from each other. The width W
of the conductive thin wire 331 is large in a small curvature
portion A with a relatively small curvature and is small in a large
curvature portion B with a relatively large curvature. As a result
of intensive research by the inventors of the present invention, by
making the width W of the conductive thin wire 331 be large in the
small curvature portion A and be small in the large curvature
portion B, it can be effectively prevented that the small curvature
portion A is visually recognized as dots, and as a result, the
heat-generating conductor 330 can be effectively made
invisible.
[0377] Next, an example of a manufacturing method for the
heat-generating plate 310 will be described with reference to FIGS.
35 to 43. FIGS. 35 to 38 and FIGS. 41 to 43 are cross-sectional
views sequentially illustrating the example of the manufacturing
method for the heat-generating plate 310. FIGS. 39 and 40 are views
for explaining spread of an etchant for etching to be described
later.
[0378] First, as illustrated in FIG. 35, a dark color film 337a
that forms the first dark color layer 337 is formed on the base
film 321. As the base film 321, any material can be used as long as
the material can appropriately hold the heat-generating conductor
330. For example, polyethylene terephthalate, polyethylene
naphthalate, polycarbonate, polystyrene, and cyclic polyolefine can
be exemplified. In consideration of retention of the
heat-generating conductor 330 and the like, it is preferable to use
the base film 321 having the thickness of equal to or more than 30
.mu.m and equal to or less than 150 .mu.m. Furthermore, the dark
color film 337a can be provided, for example, by a plating method
including electroplating and electroless plating, a sputtering
method, a CVD method, a PVD method, and an ion plating method or a
method of combination of two or more methods described above. As a
material of the dark color film 337a, various known materials can
be used. For example, copper nitride, copper oxide, nickel nitride
can be used.
[0379] Next, as illustrated in FIG. 36, a metal film 336a that
forms the conductive metal layer 336 is provided on the dark color
film 337a. As already described as a material forming the
conductive metal layer 336, the metal film 336a may be formed by
using one or more of gold, silver, copper, platinum, aluminum,
chromium, molybdenum, nickel, titanium, palladium, indium, and
tungsten, and an alloy of these metals. The metal film 336a may be
formed by a known method. For example, a method of bonding a metal
foil such as a copper foil, a plating method including
electroplating and electroless plating, a sputtering method, a CVD
method, a PVD method, an ion plating method, or a method of
combination of two or more methods described above can be
employed.
[0380] Next, as illustrated in FIG. 37, a resist pattern 339 is
provided on the metal film 336a, and an etched material (in
illustrated example, sheet-like member to be etched) 340 is
created. The resist pattern 339 has a shape corresponding to the
heat-generating conductor 330 to be formed. In the method described
here, the resist pattern 339 is provided only on a portion finally
forming the heat-generating conductor 330. The resist pattern 339
can be formed by patterning using a known photolithography
technique.
[0381] Next, as illustrated in FIG. 38, the metal film 336a and the
dark color film 337a of the etched material 340 are etched using
the resist pattern 339 as a mask. By this etching, the metal film
336a and the dark color film 337a are patterned to substantially
the same pattern as the resist pattern 339. As a result, the
conductive metal layer 336 that will form a part of the conductive
thin wire 331 is formed from the patterned metal film 336a. The
first dark color layer 337 that will form a part of the conductive
thin wire 331 and coupling conductive thin wire 332 is formed from
the patterned dark color film 337a.
[0382] Here, an etching method will be described with reference to
FIGS. 39 and 40. First, as illustrated in FIG. 39, the etched
material (in illustrated example, sheet-like member to be etched)
340 is moved in a direction of an arrow. At this time, an extending
direction of the resist pattern 339, that is, an extending
direction of the conductive metal layer 336 generated after etching
is corresponded to a traveling direction of the etched material
340. Then, to the moving etched material 340, the etchant is spread
from a spray 350 provided above the etched material 340. At this
time, while the spray 350 is vertically shaken relative to the
traveling direction of the etched material 340, the etchant is
spread. According to this aspect, the etchant can be uniformly
spread in a direction perpendicular to the extending direction of
the resist pattern 339. Furthermore, by adjusting an amount of
spread etchant from the spray 350 and a traveling speed of the
etched material 340, a degree of progress of etching relative to
the entire etched material 340 can be adjusted.
[0383] When the etchant is spread as described above, since the
etchant remains diffused in a portion of the resist pattern 339
with a small curvature as a region A' in FIG. 40, the progress of
etching is relatively slow. Therefore, finally, the width of the
conductive metal layer 336 forming the conductive thin wire 331 is
widened. That is, in the small curvature portion A illustrated in
FIG. 33, the line width W of the conductive thin wire 331 is
relatively wider. On the other hand, since the etchant concentrates
in a portion of the resist pattern 339 with a large curvature as a
region B', the progress of etching is relatively fast. Therefore,
finally, the width of the conductive metal layer 336 forming the
conductive thin wire 331 is narrowed. That is, in the large
curvature portion B illustrated in FIG. 33, the line width W of the
conductive thin wire 331 is relatively thinner. That is, with the
etching method illustrated in FIG. 39, by adjusting the amount of
spread etchant from the spray 350 and the traveling direction of
the etched material 340, the width W of the conductive thin wire
331 can be controlled according to the curvature of the resist
pattern 339, that is, the curvature of the conductive thin wire 331
to be formed.
[0384] In this way, according to the amount of spread etchant of
the resist pattern 339 and the traveling speed of the etched
material 340, the width of the conductive metal layer 336 finally
forming the conductive thin wire 331 can be easily adjusted. The
etching is adjusted so as not to excessively proceeded in a portion
of the resist pattern 339 with a large curvature. As described
above, the etched material 340 is etched, and the conductive metal
layer 336 and the first dark color layer 337 are formed. After
that, as illustrated in FIG. 41, the resist pattern 339 is
removed.
[0385] Next, as illustrated in FIG. 42, a second dark color layer
338 is formed on a surface 331a opposite to a surface 331b of the
conductive metal layer 336 on which the first dark color layer 337
is provided and side surfaces 331c and 331d. By performing
darkening processing (blackening processing) on a part of the
material forming the conductive metal layer 336, the second dark
color layer 338 formed of metal oxide or metal sulfide can be
formed from a part of the conductive metal layer 336. Furthermore,
the second dark color layer 338 may be provided on the surface of
the conductive metal layer 336 as a coating film of a dark color
material and a plating layer of nickel or chromium. In addition,
the second dark color layer 338 may be provided by roughening the
surface of the conductive metal layer 336. According to the above
process, the sheet with a conductor 320 is produced.
[0386] Finally, as illustrated in FIG. 43, the bonding layer 313
and the glass 311 are laminated from the side of the
heat-generating conductor 330 of the sheet with a conductor 320,
and the sheet with a conductor 320 is bonded to the glass 311 by
heating and pressurizing. Similarly, by laminating the bonding
layer 314 and the glass 312 from the side of the base film 321, the
sheet with a conductor 320 is bonded to the glass 312. Accordingly,
the heat-generating plate 310 illustrated in FIG. 31 is
produced.
[0387] As described above, the heat-generating plate 310 according
to the present embodiment is a heat-generating plate that generates
heat when a voltage is applied and includes the pair of glasses 311
and 312, the pair of bus bars 325 to which the voltage is applied,
and the heat-generating conductors 330 for coupling between the
pair of bus bars 325, and the heat-generating conductor 330
includes the plurality of conductive thin wires 331 that linearly
extends between the pair of bus bars 325 and couples the bus bars
325, and the average W.sub.ave of the width W of the bottom portion
of the conductive thin wire 331 is within a range of the following
formula (a) relative to the standard deviation a of the
distribution of the width W.
0.ltoreq.4.sigma./W.sub.ave.ltoreq.0.3 Formula(a)
[0388] According to the heat-generating plate 310, a difference of
the width W of the bottom portion of the conductive thin wire 331
is small as a whole, disconnection of the conductive thin wire 331
of the heat-generating conductor 330 hardly occurs, and the width
of the conductive thin wire 331 can be set within a range in which
the conductive thin wire 331 is not visually recognized. Therefore,
uneven heat hardly occurs in the heat-generating plate 310, and an
excellent visual field through the heat-generating plate 310 can be
obtained.
[0389] In the heat-generating plate 310 according to the present
embodiment, the conductive thin wire 331 includes a large curvature
portion B in which a curvature of a pattern in a plan view is
relatively large and a small curvature portion A in which a
curvature of a pattern in a plan view is relatively small. The
width W of the conductive thin wire 331 is small in the large
curvature portion B and large in the small curvature portion A.
According to the present embodiment, the heat-generating conductor
330 can be effectively made invisible.
[0390] The heat-generating plate 310 may be used for the front
window, the side window, or the sunroof of the automobile 301. In
addition, the heat-generating plate 310 may be used for a window or
a transparent door of a vehicle such as a railway vehicle, an
aircraft, a ship, and a spacecraft other than the automobile.
[0391] Furthermore, other than the vehicle, the heat-generating
plate 310 can be particularly used as a window for a building such
as a window or a transparent door of a place for dividing a space
into indoor and outdoor, for example, a building and a house.
[0392] Noted that various modifications can be made to the
embodiment.
Fifth Embodiment
[0393] FIGS. 44 to 54 are views for explaining one embodiment of
the present invention. FIG. 44 is a view schematically illustrating
an automobile including a heat-generating plate, FIG. 45 is a view
of the heat-generating plate viewed from the normal direction of
the plate surface, and FIG. 46 is a cross-sectional view of the
heat-generating plate in FIG. 45.
[0394] As illustrated in FIG. 44, an automobile 401 as an example
of a vehicle includes a window glass such as a front window, a rear
window, and a side window. Here, an example in which a front window
405 is configured by a heat-generating plate 410 will be described.
In addition, the automobile 401 includes a power supply 407 such as
a battery.
[0395] As illustrated in FIGS. 45 and 46, the heat-generating plate
410 according to the present embodiment includes a pair of glasses
411 and 412, a sheet with a conductor 420 arranged between the pair
of glasses 411 and 412, and a pair of bonding layers 413 and 414
for bonding the respective glasses 411 and 412 to the sheet with a
conductor 420. In the examples illustrated in FIGS. 44 and 45, the
heat-generating plate 410 and the glasses 411 and 412 are curved.
However, in other drawings, for easy understanding, the
heat-generating plate 410 and the glasses 411 and 412 having
plate-like shapes are illustrated.
[0396] The sheet with a conductor 420 includes a base film 421, bus
bars 425, and a heat-generating conductor 430 provided on a surface
facing to the glass 411 of the base film 421. The heat-generating
conductor 430 includes main conductive thin wires 431 and coupling
conductive thin wires 432 for connecting the main conductive thin
wires 431.
[0397] As illustrated in FIG. 45, the heat-generating plate 410
includes a wiring portion 415 for energizing the heat-generating
conductor 430 of the sheet with a conductor 420 via the bus bars
425. In the illustrated example, the power supply 407 such as a
battery supplies power to the heat-generating conductor 430 via the
wiring portion 415 and the bus bars 425, and the main conductive
thin wire 431 and the coupling conductive thin wire 432 of the
heat-generating conductor 430 are heated by resistance heating.
Heat generated by the heat-generating conductor 430 is transmitted
to the glasses 411 and 412 and heat the glasses 411 and 412. As a
result, fogging due to dew condensation attached on the glasses 411
and 412 can be removed. In a case where snow or ice is attached on
the glasses 411 and 412, snow and ice can be melted. Therefore, a
passenger's visibility is preferably secured.
[0398] Each component of the heat-generating plate 410 will be
described below.
[0399] First, the glasses 411 and 412 will be described. When the
glasses 411 and 412 are used for a front window of an automobile as
in the example illustrated in FIG. 44, it is preferable to use a
glass with a high visible light transmittance so as not to
interfere the field of view of a passenger. As a material of the
glasses 411 and 412, soda-lime glass and blue plate glass can be
used. It is preferable that a transmittance of the glasses 411 and
412 in a visible light region be equal to or higher than 90%. Here,
the visible light transmittance of the glasses 411 and 412 is
specified as an average value of transmittances in respective
wavelengths when the transmittance is measured by a
spectrophotometer ("UV-3100PC" manufactured by SHIMADZU
CORPORATION, conforming to JIS K 0115) within a measurement
wavelength range of 380 nm to 780 nm. The visible light
transmittance may be lowered by coloring a part of or all of the
glasses 411 and 412. In this case, direct sunlight can be shielded,
and it is possible to make it difficult to visually recognize an
interior of the vehicle from the outside of the vehicle.
[0400] Furthermore, it is preferable that the glasses 411 and 412
have a thickness of equal to or more than 1 mm and equal to or less
than 5 mm. With such a thickness, the glasses 411 and 412 having
excellent strength and optical characteristics can be obtained. The
pair of glasses 411 and 412 may be formed of the same material and
with the same structure, or at least one of the material and the
structure may be different.
[0401] Next, the bonding layers 413 and 414 will be described. The
bonding layer 413 is arranged between the glass 411 and the sheet
with a conductor 420 and bonds the glass 411 to the sheet with a
conductor 420. The bonding layer 414 is arranged between the glass
412 and the sheet with a conductor 420 and bonds the glass 412 to
the sheet with a conductor 420.
[0402] As such bonding layers 413 and 414, a layer formed of a
material having various adhesiveness and viscosity can be used.
Furthermore, it is preferable to use a material having a high
visible light transmittance for the bonding layers 413 and 414. As
a typical bonding layer, a layer formed of polyvinyl butyral (PVB)
can be exemplified. It is preferable that the thickness of each of
the bonding layers 413 and 414 be equal to or more than 0.15 mm and
equal to or less than 1 mm. The pair of bonding layers 413 and 414
may be formed of the same material and with the same structure, or
at least one of the material and the structure may be
different.
[0403] The heat-generating plate 410 is not limited to the
illustrated example, and other function layer that is expected to
perform a specific function may be provided. Furthermore, one
function layer may perform two or more functions, and for example,
some function may be added to at least one of the glasses 411 and
412 of the heat-generating plate 410, the bonding layers 413 and
414, and the base film 421 of the sheet with a conductor 420 to be
described later. As an example of the function that can be applied
to the heat-generating plate 410, an anti-reflection (AR) function,
a hard coating (HC) function having scratch resistance, an infrared
ray shielding (reflection) function, an ultraviolet ray shielding
(reflection) function, and an antifouling function can be
exemplified.
[0404] Next, the sheet with a conductor 420 will be described. The
sheet with a conductor 420 includes a base film 421, bus bars 425,
and a heat-generating conductor 430 provided on a surface facing to
the glass 411 of the base film 421. The heat-generating conductor
430 includes the main conductive thin wires 431 and the coupling
conductive thin wires 432. The sheet with a conductor 420 may have
substantially the same planer dimensions as the glasses 411 and 412
and be arranged across the entire heat-generating plate 410 and may
be arranged on a part of the heat-generating plate 410 such as a
front portion of a driver's seat in the example in FIG. 44.
[0405] The base film 421 functions as a base material for
supporting the heat-generating conductor 430. The base film 421 is
a so-called transparent electrically insulating substrate for
transmitting light with a wavelength in a visible light wavelength
band (380 nm to 780 nm). As the base film 421, any material can be
used as long as the material can transmit visible light and
appropriately support the heat-generating conductor 430. For
example, polyethylene terephthalate, polyethylene naphthalate,
polycarbonate, polystyrene, and cyclic polyolefine can be
exemplified. In consideration of light transmittance and
appropriate supporting property of the heat-generating conductor
430, it is preferable that the thickness of the base film 421 be
equal to or more than 0.03 mm and equal to or less than 0.20
mm.
[0406] Next, the heat-generating conductor 430 will be described
with reference to FIG. 47. FIG. 47 is a plan view illustrating the
heat-generating conductor 430 from the normal direction of the
sheet surface. FIG. 47 is a view illustrating an exemplary
arrangement of the heat-generating conductor 430.
[0407] As illustrated in FIG. 47, the heat-generating conductor 430
includes a plurality of linear main conductive thin wires 431 for
coupling a pair of bus bars 425 and coupling conductive thin wires
432 for coupling two adjacent main conductive thin wires 431. The
main conductive thin wire 431 and the coupling conductive thin wire
432 are energized from the power supply 407 such as a battery via
the wiring portion 415 and the bus bars 425 and generate heat by
resistance heating. Then, the heat is transmitted to the glasses
411 and 412 via the bonding layers 413 and 414 so as to heat the
glasses 411 and 412.
[0408] In the example illustrated in FIG. 47, each of the plurality
of main conductive thin wires 431 has a regular structure and
extends from one of the bus bars 425 to the other bus bar 425. The
main conductive thin wires 431 are arranged separated from each
other. Accordingly, a gap 435 is formed between the two adjacent
main conductive thin wires 431.
[0409] The arrangement pattern of each main conductive thin wire
431 is not limited to the pattern in FIG. 47 and may be a straight
line, a polygonal line, an irregular curve, or a combination of
these patterns. Furthermore, the main conductive thin wires 431 may
extend from one of the bus bars 425 to the other bus bar 425 in
different patterns.
[0410] As illustrated in FIG. 47, the coupling conductive thin wire
432 is arranged in the gap 435 between the two adjacent main
conductive thin wires 431 so as to couple the two adjacent main
conductive thin wires 431. Therefore, when the coupling conductive
thin wire 432 is arranged, the two adjacent main conductive thin
wires 431 are electrically connected to each other. Therefore, even
if the main conductive thin wire 431 is disconnected, electrical
connection is maintained. The coupling conductive thin wire 432 has
a shape of a straight line, a circular arc, or a combination of a
straight line and a circular arc. Furthermore, each coupling
conductive thin wire 432 has a pattern different from three or more
coupling conductive thin wires 432, or preferably, all the other
coupling conductive thin wires 432. Here, the difference in the
patterns of the coupling conductive thin wires 432 means that at
least one of the shape of the conductive thin wire and a direction
in which both ends of the coupling conductive thin wires are
coupled is different between the compared coupling conductive thin
wires 432. That is, if the directions in which both ends are
coupled of the compared coupling conductive thin wires 432 are
different from each other, even when the shapes of the coupling
conductive thin wires 432 are the same, or if the shapes are
different even when the directions in which both ends are connected
are the same, it is assumed that the patterns of the coupling
conductive thin wires 432 be different from each other.
[0411] As a material forming the heat-generating conductor 430, for
example, one or more alloys of two or more kinds of metals selected
from among metals including gold, silver, copper, platinum,
aluminum, chromium, molybdenum, nickel, titanium, palladium,
indium, and tungsten and nickel-chromium alloy, and bronze can be
exemplified.
[0412] The heat-generating conductor 430 may be formed by using an
opaque metal material as described above. On the other hand, the
main conductive thin wire 431 and the coupling conductive thin wire
432 of the heat-generating conductor 430 are formed with a high
uncoating ratio of about equal to or higher than 70% and equal to
or lower than 99.8%. Therefore, an entire region in which the main
conductive thin wires 431 and the coupling conductive thin wires
432 of the heat-generating conductor 430 are formed is transparent
and does not impair visibility.
[0413] In the example illustrated in FIG. 46, each of the main
conductive thin wire 431 and the coupling conductive thin wire 432
has a rectangular cross section as a whole. It is preferable that
the widths W of the main conductive thin wire 431 and the coupling
conductive thin wire 432, that is, the width W along the plate
surface of the heat-generating plate 410 be equal to or more than 2
.mu.m and equal to or less than 20 .mu.m and that the height
(thickness) H, that is, the height (thickness) H along the normal
direction to the plate surface of the heat-generating plate 410 be
equal to or more than 1 .mu.m and equal to or less than 60 .mu.m.
According to the main conductive thin wire 431 and the coupling
conductive thin wire 432 having such a size, since the main
conductive thin wire 431 and the coupling conductive thin wire 432
are sufficiently thinned, the heat-generating conductor 430 can be
effectively made invisible.
[0414] As illustrated in FIG. 46, each of the main conductive thin
wire 431 and the coupling conductive thin wire 432 includes a
conductive metal layer 436, a first dark color layer 437 that
covers the surface of the conductive metal layer 436 facing to the
base film 421, and a second dark color layer 438 that covers the
surface of the conductive metal layer 436 facing to the glass 411
and both side surfaces.
[0415] The conductive metal layer 436 formed of a metal material
having excellent conductivity has a relatively high reflectance.
When the conductive metal layer 436 forming the main conductive
thin wire 431 and the coupling conductive thin wire 432 of the
heat-generating conductor 430 reflects light, the reflected light
is visually recognized, and the light may interfere a field of view
of a passenger. Furthermore, when the conductive metal layer 436 is
visually recognized from outside, design may be deteriorated. Thus,
the first and second dark color layers 437 and 438 are arranged on
at least a part of the surface of the conductive metal layer 436.
It is preferable that the first and second dark color layers 437
and 438 have a lower reflectance of visible light than the
conductive metal layer 436, for example, the first and second dark
color layers 437 and 438 are layers of dark colors such as black.
With the dark color layers 437 and 438, the conductive metal layer
436 is hardly and visually recognized, and a passenger's visibility
is preferably secured. In addition, the deterioration in the design
when the viewed from outside can be prevented.
[0416] As described above, the main conductive thin wire 431 and
the coupling conductive thin wire 432 of the heat-generating
conductor 430 are formed on the base film 421 with a high uncoating
ratio from viewpoint of securing visually transmitting performance
and visibility. Therefore, as illustrated in FIG. 46, the bonding
layer 413 has contact with the base film 421 of the sheet with a
conductor 420 via a non-covered portion that is not covered with
the main conductive thin wire 431 and the coupling conductive thin
wire 432, that is, regions where the main conductive thin wire 431
and the coupling conductive thin wire 432 are not provided.
Therefore, the heat-generating conductor 430 is embedded in the
bonding layer 413.
[0417] Next, an example of a manufacturing method for the
heat-generating plate 410 will be described with reference to FIGS.
48 to 54. FIGS. 48 to 54 are cross-sectional views sequentially
illustrating the example of the manufacturing method for the
heat-generating plate 410.
[0418] First, as illustrated in FIG. 48, a dark color film 437a
that forms the first dark color layer 437 is formed on the base
film 421. As the base film 421, any material can be used as long as
the material can appropriately hold the heat-generating conductor
430. For example, polyethylene terephthalate, polyethylene
naphthalate, polycarbonate, polystyrene, and cyclic polyolefine can
be exemplified. In consideration of retention of the
heat-generating conductor 430 and the like, it is preferable to use
the base film 421 having the thickness of equal to or more than 30
.mu.m and equal to or less than 150 .mu.m. Furthermore, the dark
color film 437a can be provided by a method, for example, a plating
method including electroplating and electroless plating, a
sputtering method, a CVD method, a PVD method, and an ion plating
method or a method of combination of two or more methods described
above. As a material of the dark color film 437a, various known
materials can be used. For example, copper nitride, copper oxide,
nickel nitride can be used.
[0419] Next, as illustrated in FIG. 49, a metal film 436a that
forms the conductive metal layer 436 is provided on the dark color
film 437a. As already described as a material forming the
conductive metal layer 436, the metal film 436a may be formed by
using one or more of gold, silver, copper, platinum, aluminum,
chromium, molybdenum, nickel, titanium, palladium, indium, and
tungsten, and an alloy of these metals. The metal film 436a may be
formed by a known method. For example, a method of bonding a metal
foil such as a copper foil, a plating method including
electroplating and electroless plating, a sputtering method, a CVD
method, a PVD method, an ion plating method, or a method of
combination of two or more methods described above can be
employed.
[0420] Next, as illustrated in FIG. 50, a resist pattern 439 is
provided on the metal film 436a. The resist pattern 439 has a shape
corresponding to the heat-generating conductor 430 to be formed. In
the method described here, the resist pattern 439 is provided only
on a portion finally forming the heat-generating conductor 430. The
resist pattern 439 can be formed by patterning using a known
photolithography technique.
[0421] Next, as illustrated in FIG. 51, the metal film 436a and the
dark color film 437a are etched using the resist pattern 439 as a
mask. By this etching, the metal film 436a and the dark color film
437a are patterned to substantially the same pattern as the resist
pattern 439. As a result, the conductive metal layer 436 that will
form a part of the main conductive thin wire 431 and the coupling
conductive thin wire 432 is formed from the patterned metal film
436a. The first dark color layer 437 that will form a part of the
main conductive thin wire 431 and the coupling conductive thin wire
432 is formed from the patterned dark color film 437a.
[0422] An etching method is not particularly limited, and a known
method can be employed. As a known method, for example, wet etching
using an etchant and plasma etching can be exemplified.
Particularly, in wet etching in a "role-to-role" manner, existence
of the coupling conductive thin wire 432 can effectively prevent
collapse and peeling of the conductive metal layer 436 and the
first dark color layer 437 caused by being conveyed. After that, as
illustrated in FIG. 52, the resist pattern 439 is removed.
[0423] Next, as illustrated in FIG. 53, a second dark color layer
438 is formed on a surface 431a opposite to a surface 431b of the
conductive metal layer 436 on which the first dark color layer 437
is provided and side surfaces 431c and 431d. By performing
darkening processing (blackening processing), for example, on a
part of the material forming the conductive metal layer 436, the
second dark color layer 438 formed of metal oxide or metal sulfide
can be formed from a part of the conductive metal layer 436.
Furthermore, the second dark color layer 438 may be provided on the
surface of the conductive metal layer 436 as a coating film of a
dark color material and a plating layer of nickel or chromium. In
addition, the second dark color layer 438 may be provided by
roughening the surface of the conductive metal layer 436. According
to the above process, the sheet with a conductor 420 is
produced.
[0424] Finally, as illustrated in FIG. 54, the bonding layer 413
and the glass 411 are laminated from the side of the
heat-generating conductor 430 of the sheet with a conductor 420,
and the sheet with a conductor 420 is bonded to the glass 411, for
example, by heating and pressurizing. Similarly, by laminating the
bonding layer 414 and the glass 412 from the side of the base film
421, the sheet with a conductor 420 is bonded to the glass 412.
Accordingly, the heat-generating plate 410 illustrated in FIG. 46
is produced.
[0425] As described above, the heat-generating plate 410 according
to the present embodiment is a heat-generating plate that generates
heat when a voltage is applied and includes the pair of glasses 411
and 412, the pair of bus bars 425 to which the voltage is applied,
and the heat-generating conductor 430 for coupling between the pair
of bus bars 425, and the heat-generating conductor 430 includes the
plurality of main conductive thin wires 431 that linearly extends
between the pair of bus bars 425 and couples the bus bars 425 and
the coupling conductive thin wires 432 that couples between the two
adjacent main conductive thin wires 431, and each coupling
conductive thin wire 432 has three or more different patterns.
According to such a heat-generating plate 410, even when a certain
position of the main conductive thin wire 431 is disconnected,
electrical connection of the main conductive thin wire 431 can be
maintained by the coupling conductive thin wire 432. Therefore,
occurrence of uneven heat caused by disconnection can be prevented.
In addition, since the coupling conductive thin wire 432 has three
or more different patterns, the coupling conductive thin wire 432
is unlikely to have directivity in a specific direction. Therefore,
when the entire heat-generating plate 410 is observed, an
orientation direction of the coupling conductive thin wire 432
becomes inconspicuous. In addition, since the coupling conductive
thin wire 432 has three more different patterns, a direction of a
diffraction image generated by the coupling conductive thin wire
432 is different from a direction of a diffraction image generated
by the other coupling conductive thin wire 432. That is, a
direction in which the diffraction image grows stronger is hardly
generated in the whole coupling conductive thin wire 432.
Therefore, strong streaky light, that is, a beam of light does not
occur in a specific direction. Therefore, deterioration in
visibility through the heat-generating plate 410 can be
avoided.
[0426] In addition, in the heat-generating plate 410 according to
the present embodiment, each coupling conductive thin wire 432 has
a pattern different from those of all the other coupling conductive
thin wires 432. According to such a heat-generating plate 410, an
effect such that a beam of light hardly occurs in the specific
direction and an effect such that the coupling conductive thin wire
432 is inconspicuous in a specific arrangement direction can be
more enhanced. Therefore, an effect for avoiding the deterioration
of the visibility through the heat-generating plate 410 can be more
enhanced.
[0427] The heat-generating plate 410 may be used for the front
window, the side window, or the sunroof of the automobile 401. In
addition, the heat-generating plate 410 may be used for a window or
a transparent door of a vehicle such as a railway vehicle, an
aircraft, a ship, and a spacecraft other than the automobile.
[0428] Furthermore, the heat-generating plate 410 can be
particularly used as a window for a building such as a window or a
transparent door of a place for dividing a space into indoor and
outdoor, for example, a building and a house other than a
vehicle.
[0429] Noted that various modifications can be made to the
embodiment.
Sixth Embodiment
[0430] FIG. 55 is a plan view of a conductive heat-generating body
505 according to an embodiment of the present invention. The
conductive heat-generating body 505 in FIG. 55 includes, for
example, a heat-generating body row 533 including a plurality of
curved heat-generating bodies 532 arranged in a range 531 of 80 mm
square. As illustrated in FIG. 56, a plurality of heat-generating
body rows 533 is arranged in each of vertical and horizontal
directions. The length of 80 mm is an example, and the value can be
arbitrarily changed. As will be described later, in the present
embodiment, shapes of the curved heat-generating bodies 532
included in the single heat-generating body row 533 are irregularly
formed. However, when the heat-generating body rows 533 are
arranged in the vertical and horizontal directions, each curved
heat-generating body 532 has a periodic structure in a unit of the
heat-generating body row 533.
[0431] Even when each curved heat-generating body 532 has a
periodic structure, to make a beam of light and flicker be
inconspicuous, it has been known that the size of the
heat-generating body row 533 is increased to a certain degree.
Specifically, when a length of a side of the heat-generating body
row 533 exceeds 50 mm, even when the plurality of heat-generating
body rows 533 is arranged in the vertical and horizontal
directions, a beam of light and flicker are inconspicuous.
Hereinafter, as an example, the vertical and horizontal sizes of
the heat-generating body row 533 are set to 80 mm.
[0432] Each curved heat-generating body 532 included in the
heat-generating body row 533 is a linear heating wire formed of a
conductive material such as tungsten and copper. A line width of
each curved heat-generating body 532 is, for example, 5 to 20
.mu.m, and preferably, 7 to 10 .mu.m. To make it difficult to
visually recognize the plurality of curved heat-generating bodies
532 arranged on a transparent base material, it is desirable that
the line width of the curved heat-generating body 532 be equal to
or less than 15 .mu.m. However, as the line width decreases,
disconnection tends to occur. Therefore, to prevent the
disconnection, it is preferable to secure the line width of equal
to or more than 10 .mu.m.
[0433] The curved heat-generating bodies 532 in FIG. 55 are
arranged separated from each other in a first direction x and
extend in a second direction y intersecting with the first
direction x. In FIG. 55, although an example is illustrated in
which the first direction x and the second direction y are
perpendicular to each other, an angle between the two directions is
not necessarily a right angle.
[0434] Each curved heat-generating body 532 in FIG. 55 is obtained
by sequentially connecting a plurality of periodic curved lines of
which periods and amplitudes are irregular for each period (for
example, sine waves) to each other in the second direction y. In
FIG. 55, an example is illustrated in which the periodic curved
line is a sine wave. However, a plurality of arbitrary periodic
curved lines other than sine waves may be connected to each other.
Although a kind of the periodic curved line is arbitrary, the kinds
of connected periodic curved lines are the same, and the period and
the amplitude are irregular for each period. The sine wave is
referred to as a sinusoidal wave. A general formula expressed in a
coordinate system XY as illustrated in FIG. 55 is X=A
sin{(2.pi./.lamda.)X+.alpha.}. Here, a reference numeral A
indicates an amplitude, a reference numeral .lamda. indicates a
wavelength (or period, and a reference numeral .alpha. indicates a
phase. Furthermore, as a periodic curved line other than a sine
wave, an elliptic function curve, a Bessel function curve, and the
like can be exemplified.
[0435] Here, the term "irregular" means that the period and the
amplitude of the periodic curved line are random for each period,
and the periods and the amplitudes of the periodic curved lines do
not have periodicity in the range 531 of 80 mm square. The periods
and the amplitudes of the curved heat-generating bodies 532
arranged apart from each other in the first direction x are
irregular.
[0436] In this way, the plurality of curved heat-generating bodies
532 arranged in 80 mm square has irregular periods and amplitudes
in the first direction x and the second direction y.
[0437] When it is assumed that a lower left corner in FIG. 55 be an
origin (0, 0) and a start point of each of the curved
heat-generating bodies 532 (head position) be the minimum
coordinate position in the second direction y, the start positions
of the curved heat-generating bodies 532, arranged separated from
each other along the first direction x, in the second direction y
are irregular. This indicates that the phases of the curved
heat-generating bodies 532 are irregularly shifted from each
other.
[0438] The reason for irregularly shifting the phases of the curved
heat-generating bodies 532 is as follows. For example, when it is
assumed that all the start points of the curved heat-generating
bodies 532 be a coordinate position y=0 in the second direction y,
the amplitude of each curved heat-generating body 532 is zero at
the coordinate position y=0. Therefore, when it is assumed that the
plurality of heat-generating body rows 533 of 80 mm square be
arranged in the first direction x and the second direction y, in
each heat-generating body row 533, a position where the amplitudes
of the curved heat-generating bodies 532 are zero periodically
appears, and this position may cause a beam of light and
flicker.
[0439] Therefore, in the present embodiment, by irregularly
shifting the minimum coordinate positions of the curved
heat-generating bodies 532 included in the heat-generating body row
533 of 80 mm square in the second direction y, the phases of the
curved heat-generating bodies 532 are randomized.
[0440] As described above, in the present embodiment, for example,
since the periods and the amplitudes of the curved heat-generating
bodies 532 are formed to be irregular in the first direction x and
the second direction y in the range 531 of 80 mm square, there is
less possibility that reflected light beams reflected by the curved
heat-generating bodies 532 are interfered with each other, and
occurrence of a beam of light can be prevented. In addition, since
each curved heat-generating body 532 meanders and a meandering
sizes are irregular, a traveling direction of the reflected light
reflected by each curved heat-generating body 532 is irregular, and
strong flicker in a specific direction is hardly felt.
[0441] In the present embodiment, uneven heat is prevented, for
example, in each heat-generating body row 533 of 80 mm square.
[0442] Generally, as a curve of the curved heat-generating body 532
is gentler, that is, as the curve is closer to a straight line, a
heat generation efficiency increases. Therefore, from the viewpoint
of improving the heat generation efficiency, it is desirable to
lengthen the period of the curved heat-generating body 532 and
narrow the amplitude. On the other hand, from the viewpoint of
preventing a beam of light and flicker, it is preferable to shorten
the period of the curved heat-generating body 532 and widen the
amplitude. Since both conditions conflict with each other, it is
desirable to set the period and the amplitude of the curved
heat-generating body 532 in consideration of both the heat
generation efficiency and the prevention of a beam of light and
flicker.
[0443] If the periods and the amplitudes of the curved
heat-generating bodies 532 of 80 mm square are set in consideration
of only the prevention of a beam of light and flicker, some places
have a large heating value and some places have a small heating
value in the range 531 of 80 mm square, and uneven heat may
occur.
[0444] Therefore, in the present embodiment, a ratio of the length
of each curved heat-generating body 532 in the second direction y
and a linear distance (=80 mm) of the range 531 of 80 mm square in
the second direction y is within a range between a predetermined
upper limit and a predetermined lower limit. According to the
examination by the inventors, the upper limit of the ratio with
which uneven heat does not occur and a beam of light and flicker
can be prevented to a practically acceptable level is 1.5, and the
lower limit is 1.0.
[0445] From this fact, in the present embodiment, a ratio of the
length of each curved heat-generating body 532 relative to a
shortest distance of each curved heat-generating body 532 in 80 mm
square is set to be larger than 1.0 and set to 1.5. While
maintaining the ratio, by making the periods and the amplitudes of
the curved heat-generating bodies 532 in 80 mm square be irregular
and irregularly setting the start point coordinate positions of the
curved heat-generating bodies 532 in the second direction y, a beam
of light and flicker can be effectively prevented.
[0446] Regarding the length L of the curved heat-generating body
532, when it is assumed that a start point coordinate of the curved
heat-generating body 532 in the second direction y be y0, a
terminate point coordinate be y1, and the shortest distance between
both end points of the curved heat-generating body 532 in the
second direction y be D, it is necessary to set the ratio within a
range indicated by the following expression (1).
[ Expression 1 ] 1.0 < 1 D .intg. y = y 0 y = y 1 1 + ( dx dy )
2 dy .ltoreq. 1.5 ( 1 ) ##EQU00001##
[0447] According to further examination by the inventors, it has
been found that the ratio with which uneven heat does not occur and
a beam of light and flicker can be prevented has a lower limit of
1.01 and an upper limit of 1.15. That is, it has been found that an
optimal range of the ratio is expressed by the following expression
(2).
[ Expression 2 ] 1.01 < 1 D .intg. y = y 0 y = y 1 1 + ( dx dy )
2 dy .ltoreq. 1.15 ( 2 ) ##EQU00002##
[0448] Furthermore, as the line width of the curved heat-generating
body 532 is narrowed, the curved heat-generating body 532 is more
hardly and visually recognized. Therefore, the narrower line width
is preferable when the curved heat-generating body 532 is
incorporated in a window glass and the like. However, the curved
heat-generating body 532 is easily disconnected. Therefore, in the
present embodiment, the two curved heat-generating bodies 532
adjacent to each other in the second direction y may be connected
with a bypass heat-generating body 534. When the bypass
heat-generating bodies 534 are periodically arranged, this may
cause a beam of light and flicker. Therefore, the bypass
heat-generating bodies 534 are irregularly arranged. In addition,
the bypass heat-generating bodies 534 are equally arranged in the
heat-generating body row 533 within the range 531 of 80 mm square
so that the bypass heat-generating body 534 does not cause uneven
heat.
[0449] The periods and the amplitudes of the curved heat-generating
bodies 532 included in the heat-generating body row 533 can be
automatically generated by using a computer. FIG. 57 is a block
diagram illustrating a schematic configuration of a heat-generating
body generating device 541 that automatically generates the
plurality of curved heat-generating bodies 532 included in the
heat-generating body row 533. The heat-generating body generating
device 541 in FIG. 57 includes a parameter acquiring unit 542, a
curved heat-generating body generating unit 543, a normalizing unit
544, a heat unevenness determining unit 545, a curved
heat-generating body storing unit 546, a heat-generating body group
generating unit 547, a phase adjusting unit 548, and a
heat-generating body row storing unit 549.
[0450] The heat-generating body generating device 541 in FIG. 57
can be realized as software that can be executed by a computer.
Alternatively, at least a part of components in the heat-generating
body generating device 541 in FIG. 57 may be realized by hardware.
That is, the heat-generating body generating device 541 in FIG. 57
is not necessarily realized by a single computer.
[0451] The parameter acquiring unit 542 acquires a parameter group
including various parameters representing features of shape of the
curved heat-generating bodies 532. The parameter acquiring unit 542
may store the parameter group in a database and the like in advance
and acquire a necessary parameter from the stored parameter group
or may acquire each parameter that is input or selected by an
operator with a keyboard, a mouse, and the like.
[0452] For example, the following items 1) to 7) are considered as
examples of the parameters included in the parameter group.
[0453] 1) Minimum distance and maximum distance between two curved
heat-generating bodies 532 adjacent to each other in first
direction x.
[0454] 2) Minimum value and maximum value of amplitude of each
curved heat-generating body 532.
[0455] 3) Minimum value and maximum value of period of each curved
heat-generating body 532.
[0456] 4) Minimum value and maximum value of phase of each curved
heat-generating body 532.
[0457] 5) Minimum value and maximum value of ratio of length of
each curved heat-generating body 532 relative to minimum distance
of heat-generating body row 533 in the second direction y.
[0458] 6) Length of heat-generating body row 533 in first direction
x and length in second direction y.
[0459] 7) Number of curved heat-generating bodies 532 included in
heat-generating body row 533.
[0460] The curved heat-generating body generating unit 543
generates a single curved heat-generating body 532 extending in the
second direction y. More specifically, the curved heat-generating
body generating unit 543 connects the plurality of periodic curved
lines, having the periods and the amplitudes that are irregular for
each period, in the second direction y and generates the single
curved heat-generating body 532.
[0461] To match the shortest distance between both ends of the
curved heat-generating body 532 generated by the curved
heat-generating body generating unit 543 in the second direction y
to 80 mm, the normalizing unit 544 adjusts the periods of the
plurality of periodic curved lines included in the curved
heat-generating body 532.
[0462] The heat unevenness determining unit 545 determines whether
a ratio obtained by dividing a total length of the curved
heat-generating body 532 normalized by the normalizing unit 544 in
the second direction y by the shortest distance between the both
ends of the curved heat-generating body 532 is within a
predetermined range. The predetermined range is, for example, a
range in which the ratio is larger than 1.0 and equal to or less
than 1.5.
[0463] When the heat unevenness determining unit 545 determines
that the ratio is not within the predetermined range, the curved
heat-generating body generating unit 543 generates the curved
heat-generating body 532 again. The curved heat-generating body
storing unit 546 stores the curved heat-generating body 532 of
which the ratio is determined to be within the predetermined
range.
[0464] The heat-generating body group generating unit 547 generates
the plurality of curved heat-generating bodies 532 included in the
range 531 of 80 mm square. More specifically, the heat-generating
body group generating unit 547 generates the plurality of curved
heat-generating bodies 532 arranged apart from each other in the
first direction x within the range 531 of 80 mm square in
cooperation with the curved heat-generating body generating unit
543, the heat unevenness determining unit 545, and a unit pressure
heat-generating body storing unit.
[0465] The phase adjusting unit 548 makes the phases of the curved
heat-generating bodies 532 generated by the heat-generating body
group generating unit 547 be irregular. More specifically, the
phase adjusting unit 548 makes the start positions (head position)
of the curved heat-generating bodies 532 in the second direction y
be irregular within the range 531 of 80 mm square. The
heat-generating body row storing unit 549 stores the plurality of
curved heat-generating bodies 532 of which the phase is made to be
irregular by the phase adjusting unit 548.
[0466] FIG. 58 is a flowchart illustrating an example of a
processing procedure of the heat-generating body generating device
541 in FIG. 57. In this flowchart, processing for generating the
plurality of curved heat-generating bodies 532 included in the
heat-generating body row 533 within the range 531 of 80 mm square
is performed. Hereinafter, an example will be described in which
the plurality of periodic curved lines included in the curved
heat-generating body 532 is a sine wave.
[0467] First, the parameter acquiring unit 542 acquires parameters
in 1) to 7) (step S1). Next, the curved heat-generating body
generating unit 543 sets a start point coordinate of the sine wave
in the second direction y to zero (step S2). Next, the curved
heat-generating body generating unit 543 sets the start point
coordinate of the sine wave in the first direction x to zero (step
S3). Then, the curved heat-generating body generating unit 543
randomly sets a period and an amplitude of the sine wave based on
the acquired parameter and generates a sine wave for one period
along the second direction y (step S4).
[0468] Next, the curved heat-generating body generating unit 543
updates a coordinate position in the second direction y by adding
the sine wave for one period set in step S4 (step S5). Next, the
curved heat-generating body generating unit 543 determines whether
the added length in the second direction y exceeds 80 mm (step S6).
If the length does not exceed 80 mm, processing in steps S4 to S6
is repeated.
[0469] When it is determined that the length exceeds 80 mm in step
S6, the normalizing unit 544 adjusts the period of each sine wave
included in the curved heat-generating body 532 so that the
shortest distance between both ends of the curved heat-generating
body 532 in the second direction y is 80 mm (step S7). This
operation is called normalization processing. In the normalization
processing, the period of each sine wave included in the curved
heat-generating body 532 is decreased at the same ratio.
[0470] Next, the heat unevenness determining unit 545 determines
whether a ratio obtained by dividing a total length of the
normalized curved heat-generating body 532 in the second direction
y by the shortest distance between both ends in the second
direction y (for example, 80 mm) is within a predetermined range
(step S8). Here, for example, it is determined whether the ratio is
larger than 1.0 and equal to or less than 1.5 based on the above
expression (1).
[0471] If the ratio is not within the predetermined range, the
procedure returns to step 2, and the curved heat-generating body
532 is generated again. The reason why the curved heat-generating
body 532 is generated again in a case where the ratio of the curved
heat-generating body 532 is not within the predetermined range is
because uneven heat may occur in unit of the heat-generating body
row 533 of 80 mm square in a case where the value of the ratio is
largely different.
[0472] When it is determined in step S8 that the ratio is within
the predetermined range, the normalized curved heat-generating body
532 is stored in the curved heat-generating body storing unit 546
(step S9).
[0473] Next, the heat-generating body group generating unit 547
sets a coordinate position that is shifted in the first direction x
by one pitch based on the parameter acquired by the parameter
acquiring unit 542 (step S10). The size of one pitch is set by the
parameter acquired in step S1.
[0474] Next, the heat-generating body group generating unit 547
determines whether the length in the first direction x exceeds 80
mm (step S11). If the length does not exceed 80 mm, the processing
in and after step S2 is repeated, and a new curved heat-generating
body 532 is generated.
[0475] When it is determined in step S11 that the length exceeds 80
mm, the phase adjusting unit 548 adjusts to make the phases of the
curved heat-generating bodies 532 included in the heat-generating
body row 533 be irregular (step S12). Next, the plurality of curved
heat-generating bodies 532 of which the phase has been adjusted is
stored in the heat-generating body row storing unit 549 (step
S13).
[0476] An arbitrary number of heat-generating body rows 533 of 80
mm square generated by the processing procedure in FIG. 58 are
aligned in the vertical and horizontal directions as illustrated in
FIG. 56 to produce the conductive heat-generating body 505 with an
arbitrary size and an arbitrary shape. Although the conductive
heat-generating body 505 according to the present embodiment can be
used for various objects and applications, an example will be
described below in which the conductive heat-generating body 505
according to the present embodiment is incorporated into a front
window, a rear window, a side window, or the like of a vehicle.
[0477] Although not illustrated in the flowchart in FIG. 58, as
illustrated in FIG. 59, it is desirable to provide the bypass
heat-generating body 534 for connecting two adjacent curved
heat-generating bodies 532 in the first direction x in the
conductive heat-generating body 505. Even if an arbitrary curved
heat-generating body 532 is disconnected, the bypass
heat-generating body 534 can supply current via the curved
heat-generating body 532 adjacent to the disconnected one. The
bypass heat-generating body 534 may be generated after generating
the plurality of curved heat-generating bodies 532 in the range 531
of 80 mm square, or at the time when the two curved heat-generating
bodies 532 adjacent to each other in the first direction x are
generated, the bypass heat-generating body 534 for connecting these
two curved heat-generating bodies 532 may be generated.
[0478] The bypass heat-generating body 534 has the same line width
(for example, 5 to 20 .mu.m, preferably 7 to 10 .mu.m) as the
curved heat-generating body 532, and the bypass heat-generating
bodies 534 are arranged in the heat-generating body row 533 of 80
mm square at a uniform density. By arranging the bypass
heat-generating bodies 534 with a uniform density, uneven heat in
the heat-generating body row 533 can be prevented. The bypass
heat-generating bodies 534 connected to the respective curved
heat-generating bodies 532 are irregularly arranged.
[0479] FIG. 60 illustrates an example in which the conductive
heat-generating body 505 according to the present embodiment is
incorporated into a front window 502 of a car. The front window 502
is a laminated glass to which the conductive heat-generating body
505 is incorporated.
[0480] The front window 502 in FIG. 60 includes a pair of glass
plates 503 and 504 and the conductive heat-generating body 505
arranged between the pair of glass plates 503 and 504. The
conductive heat-generating body 505 includes two bus bar electrodes
(first and second electrodes) 506 and 507 and a plurality of wavy
line conductors 508 connected to the bus bar electrodes. In FIG.
60, each wavy line conductor 508 is illustrated as a straight line,
the wavy line conductor 508 is actually formed by connecting
periodic curved lines of which a period and an amplitude are
irregular, as illustrated in FIG. 55.
[0481] More specifically, the plurality of wavy line conductors 508
is formed by combining the plurality of heat-generating body rows
533 described above. That is, both ends of each wavy line conductor
508 are respectively connected to the two bus bar electrodes 506
and 507, and each wavy line conductor 508 is formed by connecting
single curved heat-generating bodies 532 in each of the plurality
of heat-generating body rows 533 arranged in the second direction y
as illustrated in FIG. 55.
[0482] In the example in FIG. 60, the two bus bar electrodes 506
and 507 are arranged along both side of the front window 502 in the
longitudinal direction. However, as illustrated in FIG. 61, it is
possible that the two bus bar electrodes 506 and 507 are arranged
along both sides of the front window 502 in the short-side
direction and the plurality of wavy line conductors 508 is arranged
along the longitudinal direction of the front window 502.
[0483] The shapes of the wavy line conductors 508 in FIGS. 60 and
61 are irregular. However, intervals (pitch) between reference
lines (broken line 532a in FIG. 55) of the wavy line conductors 508
are substantially constant, and the reference lines are
substantially parallel. For example, eight or less wavy line
conductors 508 are arranged per cm of the front window 502 in the
longitudinal direction. That is, it is desirable that the pitch of
the wavy line conductors 508 be equal to or more than 0.125 cm.
[0484] The plurality of wavy line conductors 508 and the two bus
bar electrodes 506 and 507 are formed of a common conductive
material and are integrally molded. As the conductive material, for
example, copper which has excellent conductivity and is easily
etched is used. As will be described later, in the present
embodiment, the plurality of wavy line conductors 508 and the two
bus bar electrodes 506 and 507 are integrally formed by
photolithography. A conductive material other than copper may be
used as long as the material has excellent conductivity and can be
easily processed by photolithographic etching.
[0485] By applying a predetermined voltage between the two bus bar
electrodes 506 and 507, a current flows into the plurality of wavy
line conductors 508 between the bus bar electrodes 506 and 507, and
a resistance component of each wavy line conductor 508 heats each
wavy line conductor 508. As a result, the pair of glass plates 503
and 504 is heated, and fogging caused by dew condensation attached
on the glass plates can be removed. In addition, snow or ice
attached on the outer glass plate can be melted. Therefore, a
passenger's visibility in the vehicle is preferably secured. In
this way, the conductive heat-generating body 505 functions as a
defroster electrode.
[0486] Since it is necessary for the bus bar electrodes 506 and 507
to apply voltage to each wavy line conductor 508 without power
loss, the width of each of the bus bar electrodes 506 and 507 in
the short-side direction is larger than the width of each wavy line
conductor 508 in the short-side direction. In the present
embodiment, since the patterns of the bus bar electrodes 506 and
507 and the wavy line conductors 508 are formed by etching a copper
thin film, a width of the pattern for the bus bar electrodes 506
and 507 is formed to be larger than a width of the pattern for the
wavy line conductor 508.
[0487] The voltage to be applied to the two bus bar electrodes 506
and 507 is supplied from the battery 509 mounted on the vehicle, a
battery cell, or the like, for example, as illustrated in FIG.
62.
[0488] As illustrated in FIG. 63, the conductive heat-generating
body 505 in which the plurality of wavy line conductors 508 and the
two bus bar electrodes 506 and 507 are integrally molded is formed
on a transparent base material 511. The transparent base material
511 may be sandwiched between the pair of glass plates 503 and 504
without peeled off, only the conductive heat-generating body 505
from which the transparent base material 511 is peeled off may be
sandwiched between the pair of glass plates 503 and 504. The
transparent base material 511 on which the conductive
heat-generating body 505 is formed is referred to as a heating
element sheet 512 herein.
[0489] The wavy line conductor 508 is formed by connecting a
plurality of sine waves with irregular periods and amplitudes in
the second direction y, and the wavy line conductor 508 is formed
by etching a copper foil or coating conductive ink. For example,
when the wavy line conductor 508 is formed by etching processing,
the side surfaces of the wavy line conductor 508 are arranged in a
direction with an angle close to the right angle with respect to a
top surface and a bottom surface. Therefore, when the side surface
has a planar shape, reflected light from the side surface travels
in a specific direction, and a person in the specific direction
feels strong flicker. However, in the present embodiment, since the
wavy line conductor 508 has an irregularly curved shape, each side
surface has an irregular shape, and strong flicker is not felt in
the specific direction.
[0490] FIG. 63 is a cross-sectional view taken along a line
LXIII-LXIII in FIG. 60 of the front window 502 having the heating
element sheet 512, in which the conductive heat-generating body 505
is formed on the transparent base material 511, sandwiched between
the pair of glass plates 503 and 504. In a case of FIG. 63, the
transparent base material 511 of the heating element sheet 512 is
bonded on the one curved glass plate 503 via a bonding layer (first
bonding layer) 513. On the conductive heat-generating body 505 of
the heating element sheet 512, the other glass plate 504 is bonded
via a bonding layer (second bonding layer) 514.
[0491] Since the transparent base material 511 of the heating
element sheet 512 and the conductive heat-generating body 505 are
sufficiently thin, the heating element sheet 512 has flexibility,
and the glass plates 503 and 504 can be stably bonded to each other
in a state where the heating element sheet 512 is curved along the
curved shapes of the curved glass plates 503 and 504.
[0492] Particularly, when the glass plates 503 and 504 are used for
the front window 502 of a vehicle, it is preferable to use a glass
with a high visible light transmittance so as not to interfere the
field of view of a passenger. As a material of the glass plates 503
and 504, soda-lime glass and blue plate glass can be used. It is
preferable that a transmittance of the glass plates 503 and 504 in
a visible light region be equal to or higher than 90%. Here, the
visible light transmittance of the glass plates 503 and 504 is
specified as an average value of transmittances in respective
wavelengths when the transmittance is measured by a
spectrophotometer (for example, "UV-3100PC" manufactured by
SHIMADZU CORPORATION, conforming to JISK0115) within a measurement
wavelength range of 380 nm to 780 nm. The visible light
transmittance may be lowered by coloring a part of or all of the
glass plates 503 and 504. In this case, direct sunlight can be
shielded, and it is possible to make it difficult to visually
recognize an interior of the vehicle from the outside of the
vehicle.
[0493] Furthermore, it is preferable that the glass plates 503 and
504 have a thickness of equal to or more than 1 mm and equal to or
less than 5 mm. With such a thickness, a glass plate having
excellent strength and optical characteristics can be obtained.
[0494] The glass plates 503 and 504 are bonded to the conductive
heat-generating body 505 formed on the transparent base material
511 via the respective bonding layers 513 and 514. As such bonding
layers 513 and 514, a layer formed of a material having various
adhesiveness and viscosity can be used. Furthermore, it is
preferable to use a material having a high visible light
transmittance for the bonding layers 513 and 514. As typical
bonding layers 513 and 514, a layer formed of polyvinyl butyral
(PVB) can be exemplified. It is preferable that the thickness of
each of the bonding layers 513 and 514 be equal to or more than
0.15 mm and equal to or less than 0.7 mm.
[0495] A laminated glass such as a front window 502 is not limited
to the illustrated example, and other function layer that is
expected to perform a specific function may be provided.
Furthermore, one function layer may perform two or more functions,
and for example, various functions may be applied to at least one
of the glass plates 503 and 504 of a laminated glass 1, the bonding
layers 513 and 514, and the transparent base material 511. For
example, an anti-reflection (AR) function, a hard coating (HC)
function having scratch resistance, an infrared ray shielding
(reflection) function, an ultraviolet ray shielding (reflection)
function, a polarization function, and an antifouling function can
be exemplified.
[0496] The transparent base material 511 functions as a base
material for supporting the conductive heat-generating body 505.
The transparent base material 511 is a so-called transparent
electrically insulating substrate for transmitting light with a
wavelength in a visible light wavelength band (380 nm to 780 nm)
and includes a thermoplastic resin.
[0497] As a thermoplastic resin included in the transparent base
material 511 as a main component, any resin may be used as long as
a thermoplastic resin transmits visible light. For example, an
acrylic resin such as polymethyl methacrylate, a polyolefin resin
such as polypropylene, a polyester resin such as polyethylene
terephthalate and polyethylene naphthalate, a cellulose resin such
as triacetylcellulose (cellulose triacetate), polyvinyl chloride,
polystyrene, a polycarbonate resin, and an AS resin can be
exemplified. Especially, an acrylic resin and polyethylene
terephthalate are preferable because an acrylic resin and
polyethylene terephthalate have excellent optical characteristics
and can be easily molded.
[0498] In consideration of retention and a light transmittance of
the conductive heat-generating body 505 in production, it is
preferable that the thickness of the transparent base material 511
be equal to or more than 0.02 mm and equal to or less than 0.20
mm.
[0499] FIG. 64 is a cross-sectional view illustrating a process for
manufacturing the conductive heat-generating body 505 and
illustrates a cross-sectional structure in a direction of a line
LXIII-LXIII in FIG. 60. First, as illustrated in FIG. 64(a), a
copper thin film 521 is formed on the transparent base material
511. The thin film 521 can be formed by an electric field copper
foil, a rolled copper foil, sputtering, vacuum vapor deposition or
the like.
[0500] Next, as illustrated in FIG. 64(b), a top surface of the
copper thin film 521 is covered with a photoresist 522. The
photoresist 522 is, for example, a resin layer having
photosensitivity relative to light in a specific wavelength range,
for example, ultraviolet light. The resin layer may be formed by
adhering a resin film or may be formed by coating a fluid resin. In
addition, a specific photosensitive characteristics of the
photoresist 522 is not particularly limited. For example, as the
photoresist 522, a photocurable photosensitive material may be
used, or a light dissolving type photosensitive material may be
used.
[0501] Subsequently, as illustrated in FIG. 64(c), the photoresist
522 is patterned to form a resist pattern 523. As a method for
patterning the photoresist 522, various known methods can be
employed. However, in this example, a resin layer having
photosensitivity relative to light in a specific wavelength range,
for example, ultraviolet light is used as the photoresist 522, and
the photoresist 522 is patterned by using known photolithography
technique. First, on the photoresist 522, a mask on which a portion
to be patterned is opened or a mask in which a portion to be
patterned is shielded is arranged. As described above, on the mask,
a pattern in which both end faces extending in the longitudinal
direction of the wavy line conductor 508 meander is illustrated.
Furthermore, in some cases, a pattern in which the entire wavy line
conductor 508 in the longitudinal direction meanders may be drawn
on the mask.
[0502] Next, the photoresist 522 is irradiated with ultraviolet
rays through the mask. Thereafter, a portion where ultraviolet rays
are shielded by the mask or a portion irradiated with ultraviolet
rays is removed by a method such as development. Thus, the
patterned resist pattern 523 can be formed. A laser patterning
method performed without a mask can be used.
[0503] Next, as illustrated in FIG. 64(d), etchant for wet etching
is jet from an upper side of the resist pattern 523, and the copper
thin film 521 which is not covered with the resist pattern 523 is
etched and removed, and only a region of the copper thin film 521
covered with the resist pattern 523 is left. Next, as illustrated
in FIG. 64(e), by peeling off the resist pattern 523, the plurality
of wavy line conductors 508 and the two bus bar electrodes 506 and
507 are produced. Thereafter, the plurality of wavy line conductors
508 and the two bus bar electrodes 506 and 507 formed on the
transparent base material 511 are sandwiched and sealed between the
pair of glass plates 503 and 504.
[0504] A dark color layer to reduce the reflectance of the
conductive heat-generating body 505 may be formed on the patterned
surface of the copper thin film 521 or on a lower surface of the
copper thin film 521. By forming the dark color layer, the
reflected light in a case where external light is irradiated on the
surface of the wavy line conductor 508 can be reduced, and
occurrence of flicker can be prevented.
[0505] In a case where only the plurality of wavy line conductors
508 is formed by photolithography without integrally molding the
bus bar electrodes 506 and 507, when the etchant is jetted in an
etching process in photolithography, etching is further processed
on both ends of the wavy line conductor 508 in the longitudinal
direction than the center part in the longitudinal direction, and a
width between the both ends of the wavy line conductor 508 in the
longitudinal direction is reduced too much, and the wavy line
conductor 508 is not conducted to the bus bar electrodes 506 and
507 or resistances of both ends of the wavy line conductor 508 in
the longitudinal direction are abnormally increased. On the other
hand, in a case where the plurality of wavy line conductors 508 and
the two bus bar electrodes 506 and 507 are integrally molded as in
the present embodiment, since the etchant flowing from the center
of the wavy line conductors 508 in the longitudinal direction to
both ends is stopped by the bus bar electrodes 506 and 507, the
entire wavy line conductor 508 is evenly immersed in the etchant,
and a failure such that the both ends of the wavy line conductor
508 in the longitudinal direction are more etched and removed does
not occur.
[0506] Furthermore, in the present embodiment, since the plurality
of wavy line conductors 508 and the two bus bar electrodes 506 and
507 are integrally molded by photolithography, contact property
between the wavy line conductor 508 and the bus bar electrodes 506
and 507 is enhanced, power loss at bonding portions between the
wavy line conductor 508 and the bus bar electrodes 506 and 507 is
reduced, and a heat generation efficiency is improved than a case
where the plurality of wavy line conductors 508 is formed by
photolithography in advance and the bus bar electrodes 506 and 507
separated from the wavy line conductor 508 are bonded to the wavy
line conductor 508.
[0507] The heating element sheet 512 produced by the manufacturing
process in FIG. 64 is arranged between the pair of curved glass
plates 503 and 504. More specifically, a laminated glass is
produced by laminating the one glass plate 503, the bonding layer
513, the heating element sheet 512, the bonding layer 514, the
glass plate 504 in this order and pressurizing and heating
them.
[0508] In the manufacturing process in FIG. 64 described above, an
example has been described in which the laminated glass is formed
by sealing with the pair of glass plates 503 and 504 after the wavy
line conductor 508 and the like is formed on the transparent base
material 511 by etching and the like. However, in this example. The
transparent base material 511 is included between the pair of glass
plates 503 and 504, and the number of layers between the pair of
glass plates 503 and 504 is increased, and the increase in the
thickness increases the weight, and visibility may be deteriorated
due to a difference between the optical characteristics of the
layers. In addition, by including the transparent base material
511, heat transfer characteristics are deteriorated. In addition,
since the pair of glass plates 503 and 504 is curved as illustrated
in FIG. 63, wrinkles may occur in the transparent base material
511.
[0509] Therefore, as illustrated in FIG. 65, after the heating
element sheet 512 in which the conductive heat-generating body 516
including the bus bar electrodes 506 and 507 and the wavy line
conductor 508 is formed on the transparent base material 511 via
the peeling layer 515 is produced and the heating element sheet 512
is bonded to one glass plate, it is possible that the transparent
base material is peeled off and the other glass plate is bonded
after that. FIGS. 66 to 69 are cross-sectional views illustrating
an example of a process for manufacturing a laminated glass using
the heating element sheet 512 in FIG. 65.
[0510] First, the bonding layer 514 and the glass plate 504 are
laminated on the heating element sheet 512 from a surface on which
a heating element is formed (upper side in FIG. 66), and
subsequently, the heating element sheet 512, the bonding layer 514,
and the glass plate 504 are bonded to form a first intermediate
member 517. For example, it is possible that a laminate in which
the bonding layer 514 and the glass plate 504 are laminated on the
heating element sheet 512 is conveyed into an autoclave apparatus,
the heating element sheet 512, the bonding layer 514, and the glass
plate 504 are heated and pressurized, and the laminate is taken out
from the autoclave apparatus. In this case, if a pressure in the
autoclave apparatus is reduced before the heating element sheet
512, the bonding layer 514, and the glass plate 504 are heated and
pressurized, it is possible to prevent bubbles from remaining in
the bonding layer 514, in an interface between the bonding layer
514 and the heating element sheet 512, and an interface between the
bonding layer 514 and the glass plate 503.
[0511] As a result, as illustrated in FIG. 66, the first
intermediate member 517 in which the transparent base material 511,
the peeling layer 515, the conductive heat-generating body 516, the
bonding layer 514, and the glass plate 504 are laminated is
obtained. The bonding layer 514 of the first intermediate member
517 has a first surface 514a and a second surface 514b, and at
least a part of the conductive heat-generating body 516 is embedded
in the first surface 514a of the bonding layer 514. In the
illustrated example, the conductive heat-generating body 516 is
completely embedded in the bonding layer 514 from the side of the
first surface 514a of the bonding layer 514. As a result, the
bonding layer 514 is in surface contact with the peeling layer 515
via a gap between the conductive heat-generating bodies 516.
Furthermore, the bonding layer 514 is in surface contact with the
entire peeling layer 515 exposed in the heat-generating body row
533.
[0512] In the examples illustrated in FIGS. 66 to 70, for simple
illustration, the flat glass plates 503 and 504 are
illustrated.
[0513] However, actually, the glass plates are curved as in FIG.
63. Since the first intermediate member 517 is bonded to the glass
plate 504, the first intermediate member 517 is curved in
correspondence with the shape of the glass plate 504. Next, as
illustrated in FIG. 67, the transparent base material 511 of the
heating element sheet 512 of the first intermediate member 517 is
removed to produce a second intermediate member 518 (intermediate
member for laminated glass). In the example illustrated in FIG. 67,
the transparent base material 511 of the heating element sheet 512
is peeled off from the first intermediate member 517 using the
peeling layer 515 and is removed from the first intermediate member
517. In a case where an interface peeling type peeling layer 515
having a layer with relatively low adhesion with the bonding layer
514 and the conductive heat-generating body 516 than the adhesion
with the transparent base material 511 is used as a peeling layer
515, the peeling layer 515 is peeled off from the bonding layer 514
and the conductive heat-generating body 516. In this case, it is
possible that the peeling layer 515 does not remain on the side of
the bonding layer 514 and the conductive heat-generating body 516.
That is, the transparent base material 511 together with the
peeling layer 515 are removed from the first intermediate member
517. In the first intermediate member 517 from which the
transparent base material 511 and the peeling layer 515 are removed
in this way, the bonding layer 514 is exposed in the gap between
the conductive heat-generating bodies 516.
[0514] On the other hand, in a case where an interface peeling type
peeling layer 515 having relatively low adhesion with the
transparent base material 511 than the adhesion with the bonding
layer 514 and the conductive heat-generating body 516 is used as a
peeling layer 515, the peeling layer 515 and the transparent base
material 511 are peeled off from each other. In a case where an
interlayer peeling type peeling layer 515 that includes a plurality
of layers of films and has relatively lower adhesion between the
plurality of layers than the adhesion with the bonding layer 514,
the conductive heat-generating body 516, and the transparent base
material 511 is used as a peeling layer 515, the plurality of
layers is peeled off from each other. On the other hand, an
aggregation peeling type peeling layer 515 in which a filler as a
dispersed phase is dispersed in a base resin as a continuous phase
is used as a peeling layer 515, peeling phenomenon due to cohesive
failure in the peeling layer 515 occurs.
[0515] The bonding layer 514 of the second intermediate member 518
has a first surface 514a and a second surface 514b, and at least a
part of the conductive heat-generating body 516 is embedded in the
first surface 514a of the bonding layer 514.
[0516] A laminated glass 510 manufactured as described above is
illustrated in FIG. 68. The laminated glass 510 includes the pair
of glass plates 503 and 504, the bonding layer 514 arranged between
the pair of glass plates 503 and 504 and bonding the pair of glass
plates 503 and 504 to each other, and the conductive
heat-generating bodies 516 arranged between the bonding layer 514
and one of the pair of glass plates 503 and 504. The laminated
glass 510 can be manufactured using the heating element sheet 512
as described above. The conductive heat-generating body 516 of the
heating element sheet 512 can be produced on the transparent base
material 511 by using various materials and various methods, and in
addition, a desired pattern can be applied with high accuracy.
Therefore, it is possible to reduce adverse effects on visibility
caused by light diffusion and light diffraction in the wavy line
conductor 508 included in the conductive heat-generating body 516.
In addition, since the conductive heat-generating body 516 has
contact with one of the pair of glass plates 503 and 504, a heating
efficiency of the glass plates 503 and 504 by the conductive
heat-generating body 516 can be increased. In addition, the number
of interfaces in the laminated glass 510 can be reduced, and the
thickness of the entire laminated glass 510 can be reduced.
Therefore, deterioration in optical characteristics, that is,
deterioration in visibility can be prevented. In addition, the
weight of the entire laminated glass 510 can be reduced, and this
contributes to improve fuel consumption of a vehicle.
[0517] Furthermore, the illustrated heating element sheet 512 is in
surface contact with the glass plates 503 and 504. In such a
laminated glass 510, a heating efficiency of the glass plate by the
heating element sheet 512 can be more increased.
[0518] Furthermore, in the laminated glass 510 in FIG. 68, since
the transparent base material 511 does not exist between the curved
glass plates 503 and 504 and the heating element sheet 512, even
when the pair of glass plates 503 and 504 are curved, the bonding
layer 514 and the conductive heat-generating body 516 are easily
curved in corresponding with the curve of the glass plates 503 and
504. That is, a disadvantage such that the transparent base
material 511 causes wrinkles between the pair of glass plates 503
and 504 can be eliminated.
[0519] Furthermore, a manufacturing method illustrated in FIGS. 66
to 68 includes a process for bonding the glass plate 504 to the
heating element sheet 512 including the transparent base material
511, the peeling layer 515 provided on the transparent base
material 511, and the conductive heat-generating body 516 provided
on the peeling layer 515 from the side of the conductive
heat-generating body 516 via the bonding layer 514, a process for
removing the transparent base material 511, and a process for
bonding the other glass plate 503 to the bonding layer 514 from a
side opposite to the side facing to the glass plate 504. In this
example, since the bonding layer 514 and the conductive
heat-generating body 516 are held by the glass plate 504 when the
transparent base material 511 is peeled off from the first
intermediate member 517, the transparent base material 511 is
easily peeled off. Furthermore, since the bonding layer 514 and the
glass plate 504 are bonded to the heating element sheet 512 at a
time, there is an advantage such that the number of processes can
be reduced.
[0520] As described above, in a case where an interface peeling
type peeling layer 515 having relatively low adhesion with the
transparent base material 511 than the adhesion with the bonding
layer 514 and the heating element sheet 512 is used as a peeling
layer 515, the peeling layer 515 and the transparent base material
511 are peeled off from each other. In a case where an interlayer
peeling type peeling layer that includes a plurality of layers of
films and has relatively low adhesion between the plurality of
layers than the adhesion with the bonding layer 514, the heating
element sheet 512, and the transparent base material 511 is used as
a peeling layer 515, the plurality of layers is peeled off from
each other. In a case where an aggregation peeling type peeling
layer in which a filler as a dispersed phase is dispersed in a base
resin as a continuous phase is used as the peeling layer 515,
peeling due to cohesive failure in the peeling layer 515 occurs. In
a case where these peeling layers 515 are used, in the second
intermediate member 518 from which the transparent base material
511 is removed by using the peeling layer 515, at least a part of
the peeling layer 515 remains on the side of the bonding layer 514
and the heating element sheet 512. Therefore, a state where the
bonding layer 514 is not exposed in the gap between the wavy line
conductors 508 occurs. In this case, when the glass plate 503 is
laminated on the second intermediate member 518, it is preferable
to further provide the bonding layer 513 between the second
intermediate member 518 and the glass plate 503 to reliably bond
the glass plate 503. In this case, the peeling layer 515 remained
on the side of the bonding layer 514 and the heating element sheet
512 is a supporting layer 519 for supporting the heating element
sheet 512. As illustrated in FIG. 69, the laminated glass 510
obtained as a result of the above includes the pair of glass plates
503 and 504, the pair of bonding layers 514 and 513 arranged
between the pair of glass plates 503 and 504, the supporting layer
519 arranged between the pair of bonding layers 514 and 513, and
the heating element sheet 512 arranged between one of the pair of
bonding layers 514 and 513 and the supporting layer 519 and
supported by the supporting layer 519.
[0521] In this way, in the present embodiment, a ratio obtained by
dividing the total length of each curved heat-generating body 532
of the conductive heat-generating body 516 in the second direction
y by the shortest distance between both ends of each curved
heat-generating body 532 is set to be larger than 1.0 and equal to
or less than 1.5. With this setting, uneven heat can be surely
prevented within the range of the heat-generating body row 533
including the plurality of curved heat-generating bodies 532.
[0522] Furthermore, in the present embodiment, since the period and
the amplitude of the plurality of periodic curved lines included in
each curved heat-generating body 532 are irregular for each period,
a beam of light and flicker are not conspicuous. Furthermore, since
the start position coordinates of the curved heat-generating bodies
532 in the second direction y are irregularly shifted from each
other, even when the plurality of heat-generating body rows 533
including the plurality of curved heat-generating bodies 532 is
aligned, a beam of light and flicker are inconspicuous.
[0523] Aspects of the present invention are not limited to the
above embodiments and include various modifications that can be
conceived by those skilled in the art, and the effects of the
present invention is not limited to the contents described above.
In other words, various additions, modifications, and partial
deletion can be made without departing from the conceptual idea and
the gist of the present invention derived from the contents defined
in the claims and equivalents thereof.
Seventh Embodiment
[0524] Here, "bonding" includes not only "complete bonding" in
which bonding is completed but also so-called "temporarily bonding"
for temporarily bonding before "complete bonding".
[0525] FIGS. 70 and 71 are views for explaining one embodiment of
the present invention. FIG. 70 is a view schematically illustrating
an automobile including a heat-generating plate, FIG. 71 is a view
of the heat-generating plate viewed from the normal direction of
the plate surface, and FIG. 72 is a cross-sectional view of the
heat-generating plate in FIG. 71. Note that the heat-generating
plate according to the present embodiment may be referred to as a
laminated glass.
[0526] As illustrated in FIG. 70, an automobile 601 as an example
of a vehicle includes a window glass such as a front window, a rear
window, and a side window. Here, a front window 605 configured by a
heat-generating plate 610 is exemplified. In addition, the
automobile 601 includes a power supply 607 such as a battery.
[0527] The heat-generating plate 610 viewed from a normal direction
of a plate surface is illustrated in FIG. 71. A cross-sectional
view of the heat-generating plate 610 corresponding to a line
LXXII-LXXII in FIG. 71 is illustrated in FIG. 72. In the example
illustrated in FIG. 72, the heat-generating plate 610 includes a
pair of glass plates 611 and 612, a conductive pattern sheet
(pattern sheet) 620 arranged between the pair of glass plates 611
and 612, and bonding layers 613 and 614 for respectively bonding
the glass plates 611 and 612 to the conductive pattern sheet 620.
In the examples illustrated in FIGS. 70 and 71, the heat-generating
plate 610 is curved. However, in FIGS. 72 and 82 to 89, for simple
illustration and easy understanding, the heat-generating plate 610
and the glass plates 611 and 612 having plate-like shapes are
illustrated.
[0528] The conductive pattern sheet 620 includes a sheet-like base
material 630, a conductive pattern 640 formed on the base material
630, a wiring portion 615 for energizing the conductive pattern
640, and a connecting portion 616 for connecting the conductive
pattern 640 to the wiring portion 615.
[0529] In the examples illustrated in FIGS. 71 and 72, the power
supply 607 such as a battery including a lead storage battery and a
lithium ion storage battery, a solar battery, and a commercial AC
power supply supplies power to the conductive pattern 640 via the
wiring portion 615 and the connecting portion 616 and heats the
conductive pattern 640 by resistance heating. Heat generated by the
conductive pattern 640 is transmitted to the glass plates 611 and
612 via the bonding layers 613 and 614 and heats the glass plates
611 and 612. As a result, fogging due to dew condensation attached
on the glass plates 611 and 612 can be removed. In a case where
snow or ice is attached on the glass plates 611 and 612, snow and
ice can be melted. Therefore, a passenger's visibility is
preferably secured.
[0530] Particularly, when the glass plates 611 and 612 are used for
the front window of an automobile, it is preferable to use a glass
with a high visible light transmittance so as not to interfere the
field of view of a passenger. As a material of the glass plates 611
and 612, soda-lime glass and blue plate glass can be used. It is
preferable that a transmittance of the glass plates 611 and 612 in
a visible light region be equal to or higher than 90%. Here, the
visible light transmittance of the glass plates 611 and 612 is
specified as an average value of transmittances in respective
wavelengths when the transmittance is measured by a
spectrophotometer ("UV-3100PC" manufactured by SHIMADZU
CORPORATION, conforming to JIS K 0115) within a measurement
wavelength range of 380 nm to 780 nm. The visible light
transmittance may be lowered by coloring a part of or all of the
glass plates 611 and 612. In this case, direct sunlight can be
shielded, and it is possible to make it difficult to visually
recognize an interior of the vehicle from the outside of the
vehicle.
[0531] Furthermore, it is preferable that the glass plates 611 and
612 have a thickness of equal to or more than 1 mm and equal to or
less than 5 mm. With such a thickness, the glass plates 611 and 612
having excellent strength and optical characteristics can be
obtained.
[0532] The glass plates 611 and 612 and the conductive pattern
sheet 620 are bonded to each other via the respective bonding
layers 613 and 614. As such bonding layers 613 and 614, a layer
formed of a material having various adhesiveness and viscosity can
be used. Furthermore, it is preferable to use a material having a
high visible light transmittance for the bonding layers 613 and
614. As a typical bonding layer, a layer formed of polyvinyl
butyral (PVB) can be exemplified. It is preferable that the
thickness of each of the bonding layers 613 and 614 be equal to or
more than 0.15 mm and equal to or less than 0.7 mm.
[0533] The heat-generating plate 610 is not limited to the
illustrated example, and other function layer that is expected to
perform a specific function may be provided. Furthermore, one
functional layer may perform two or more functions, and for
example, a function may be applied to at least one of the glass
plates 611 and 612 and the bonding layers 613 and 614 of the
heat-generating plate 610 and the base material 630 of the
conductive pattern sheet 620 to be described later. As an example
of the function that can be applied to the heat-generating plate
610, an anti-reflection (AR) function, a hard coating (HC) function
having scratch resistance, an infrared ray shielding (reflection)
function, an ultraviolet ray shielding (reflection) function, a
polarization function, and an antifouling function can be
exemplified.
[0534] Next, the conductive pattern sheet 620 will be described.
The conductive pattern sheet 620 includes a sheet-like base
material 630, a conductive pattern 640 provided on the base
material 630, a wiring portion 615 for energizing the conductive
pattern 640, and a connecting portion 616 for connecting the
conductive pattern 640 to the wiring portion 615. The conductive
pattern 640 is formed by arranging conductive thin wires, formed of
metals and the like, in a predetermined pattern. The conductive
pattern sheet 620 may have substantially the same planer dimensions
as the glass plates 611 and 612 and be arranged across the entire
heat-generating plate 610 and may be arranged on a part of the
heat-generating plate 610 such as a front portion of a driver's
seat.
[0535] The sheet-like base material 630 functions as a base
material for supporting the conductive pattern 640. The base
material 630 is a so-called transparent electrically insulating
substrate for transmitting light with a wavelength in a visible
light wavelength band (380 nm to 780 nm).
[0536] Although the resin included in the base material 630 may be
any resin as long as the resin transmits visible light, a
thermoplastic resin can be preferably used. As a thermoplastic
resin, for example, an acrylic resin such as polymethyl
methacrylate, a polyester resin such as polyvinyl chloride,
polyethylene terephthalate, and amorphous polyethylene
terephthalate (A-PET), a polyethylene resin, a polyolefin resin
such as polypropylene, a cellulose resin such as triacetylcellulose
(cellulose triacetate), polystyrene, a polycarbonate resin, and an
AS resin can be exemplified. In particular, an acrylic resin and
polyvinyl chloride are preferable since an acrylic resin and
polyvinyl chloride are excellent in etching resistance, weather
resistance property, and light resistance property.
[0537] In consideration of retention and a light transmittance of
the conductive pattern 640, it is preferable that the thickness of
the base material 630 be equal to or more than 0.03 mm and equal to
or less than 0.3 mm.
[0538] With reference to FIGS. 73 to 75, the conductive pattern 640
will be described. The conductive pattern 640 is energized from the
power supply 607 such as a battery via the wiring portion 615 and
the connecting portion 616 and generates heat by resistance
heating. Then, the heat is transmitted to the glass plates 611 and
612 via the bonding layers 613 and 614 so as to heat the glass
plates 611 and 612.
[0539] Regarding the conductive pattern 640 according to the
present embodiment, a reference pattern 650 is determined which
includes a plurality of line segments 654 extending between two
branch points 652 and defining an opening region 653, and
subsequently, positions of branch points 642 of the conductive
pattern 640 are determined based on the branch points 652 of the
reference pattern 650, and after that, positions of connection
elements 644 of the conductive pattern 640 are determined based on
the determined branch points 642 of the conductive pattern 640 and
the line segments 654 of the reference pattern 650.
[0540] FIG. 73 is a plan view illustrating the reference pattern
650. As illustrated in FIG. 73, the reference pattern 650 is a mesh
pattern defining a large number of opening regions 653. The
reference pattern 650 includes the plurality of line segments 654
extending between the two branch points 652 and defining the
opening region 653. That is, the reference pattern 650 is formed as
a group of a large number of line segments 654 having the branch
points 652 formed at both ends.
[0541] In the example illustrated in FIG. 73, a large number of
opening regions 653 of the reference pattern 650 are arranged with
a shape and a pitch having no repeating regularity (periodic
regularity). In particular, in the illustrated example, a large
number of opening regions 653 are arranged so as to coincide with
Voronoi regions in the Voronoi diagram generated from virtual
points, that is, sites in which distances between adjacent points
are randomly distributed between a predetermined upper limit and a
predetermined lower limit in a planar view. In other words, each
line segment 654 of the reference pattern 650 coincides with each
boundary between the Voronoi regions in the Voronoi diagram. In
addition, each branch point 652 of the reference pattern 650
coincides with a Voronoi point in the Voronoi diagram.
[0542] The Voronoi diagram can be obtained by a known method as
disclosed in, for example, JP 2012-178556 A, JP 2011-216378 A, and
JP 2012-151116 A. Therefore, detailed description on a method for
creating the Voronoi diagram will be omitted.
[0543] FIG. 74 illustrates an enlarged view of a part of the
conductive pattern 640 with the reference pattern 650 illustrated
in FIG. 73. First, each branch point 642 of the conductive pattern
640 is arranged on each branch point 652 of the reference pattern
650. Next, each connection element 644 of the conductive pattern
640 is arranged to connect between the two branch points 642
respectively corresponding to the two branch points 652 that are
both ends of the line segment 654 of the reference pattern 650.
Each connection element 644 may be a straight line segment which is
a part of a straight line, a curved line segment which is a part of
a curved line, or a combination thereof. For example, each
connection element 644 may have a shape of a straight line segment,
a polygonal line, a curved line segment, or the like. Here, less
than 20% of the plurality of connection elements 644 is the
connection elements 644 for connecting the two branch points 642 as
a straight line segment. That is, equal to or more than 80% of the
plurality of connection elements 644 have a shape of a polygonal
line or a curved line segment other than a straight line segment. A
curved line forming the curved line segment is not particularly
limited. For example, the curved line can be appropriately selected
from among a circle, an ellipse, a cardioid, a sinusoidal curve, a
Jacobi elliptic functional curve, a hyperbolic sine function curve,
a Bessel function curve, an involute curve, a function curve of
degree of n (n is an integral of two or more) other than a circle
and an ellipse.
[0544] In the example illustrated in FIG. 74, the conductive
pattern 640 includes the plurality of branch points 642 arranged on
each branch point 652 of the reference pattern 650, and the
plurality of connection elements 644 extending between the two
branch points 642 and defining the opening region 643, and the
connection elements 644 for connecting two branch points 642 as a
straight line segment are less than 20% of the plurality of
connection elements 644. The conductive pattern 640 has a mesh
pattern in which the connection elements 644 are arranged in
correspondence with the respective line segments 654 of the
reference pattern 650.
[0545] It is not necessary to calculate and specify the ratio of
the connection elements 644 for connecting between the two branch
points 642 as a straight line segment relative to the plurality of
connection elements 644 by examining the entire region of the
conductive pattern 640. In actual, in one section having an area
expected to reflect overall tendencies of the ratio of the
connection elements 644 for connecting the two branch points 642 as
a straight line segment relative to the plurality of connection
elements 644, the ratio can be calculated and specified by
examining an appropriate number of targets in consideration of
variation in the numbers to be examined. The value specified in
this way can be used as a ratio of the connection elements 644 for
connecting the two branch points 642 as a straight line segment
relative to the plurality of connection elements 644. In the
conductive pattern 640 according to the present embodiment, by
observing 100 points included in a region of 300 mm.times.300 mm by
an optical microscope or an electron microscope, the ratio of the
connection elements 644 for connecting two branch points 642 as a
straight line segment relative to the plurality of connection
elements 644 can be specified.
[0546] As a material of such a conductive pattern 640, for example,
one or more of gold, silver, copper, platinum, aluminum, chromium,
molybdenum, nickel, titanium, palladium, indium, tungsten, and an
alloy thereof can be exemplified.
[0547] In the example illustrated in FIG. 72, the connection
element 644 includes a surface 644a on the side of the base
material 630, a surface 644b opposite to the base material 630, and
side surfaces 644c and 644d, and has a substantially rectangular
cross section as a whole. It is preferable that a width W of the
connection element 644, that is, a width W of the base material 630
along the sheet surface be equal to or more than 1 .mu.m and equal
to or less than 15 .mu.m. It is preferable that the width W of the
base material 630 along the sheet surface be equal to or more than
1 .mu.m and equal to or less than 7 .mu.m. According to the
connection element 644 having such a width W, since the connection
element 644 is sufficiently thinned, the conductive pattern 640 can
be effectively made invisible. In addition, since a sufficient
width W of the connection element 644, that is, mechanical strength
and an electric conductivity (reciprocal of electric resistance)
are ensured, the connection element 644 is hardly disconnected
during a manufacturing process and during usage of the connection
element 644 as a heat-generating plate, and a sufficient heating
value can be secured. In addition, it is preferable that a height
(thickness) H of the connection element 644, that is, the height
(thickness) H along the normal direction to the sheet surface of
the base material 630 be equal to or more than 1 .mu.m and equal to
or less than 20 .mu.m. In addition, it is more preferable that the
height H of the connection element 644 be equal to or more than 2
.mu.m and equal to or less than 14 .mu.m. The height (thickness) H
of the connection element 644 can be the height (thickness) of the
conductive pattern 640. According to the connection element 644
having such a height (thickness) H, sufficient conductivity can be
secured while having an appropriate resistance value.
[0548] According to the conductive pattern 640 as described above,
as illustrated in FIG. 75, light entering the side surface of the
connection element 644 having the shape of a curved line segment, a
polygonal line, and the like other than a straight line segment is
diffusely reflected by the side surface. As a result, the light
entering the side surface of the connection element 644 from a
certain direction can be prevented from being reflected by the side
surface in a certain direction in correspondence with the incident
direction. Therefore, it is possible to prevent that the reflected
light is observed by an observer and the conductive pattern 640
having the connection element 644 is visually recognized by the
observer. In particular, in a case where the connection elements
644 for connecting between the two branch points 642 as a straight
line segment are less than 20% of the plurality of connection
elements 644, that is, in a case where more than 80% of the
plurality of connection elements 644 have shapes such as a curved
line segment or a polygonal line other than a straight line
segment, it can be more effectively prevented that the light
reflected by the side surface of the connection element 644 is
visually recognized by the observer and the conductive pattern 640
including the connection element 644 is visually recognized by the
observer.
[0549] In a case where the height (thickness) H of the connection
element 644 is equal to or more than 1 .mu.m, in particular, in a
case where the height H of the connection element 644 is equal to
or more than 2 .mu.m, a possibility such that the light reflected
by the side surface of the connection element 644 is observed by
the observer is increased. Therefore, in this case, to prevent that
the light reflected by the side surface of the connection element
644 is visually recognized by the observer, it is especially more
effective that the connection elements for connecting the two
branch points 642 as a straight line segment are less than 20% of
the plurality of connection elements 644.
[0550] In addition, when the distribution of the opening regions
643 is coarse and an average distance D.sub.ave between median
points of the two adjacent opening regions 643 becomes longer, each
connection element 644 is lengthened. When each connection element
644 is lengthened, the light reflected by the side surface of the
connection element 644 in a predetermined direction is easily and
visually recognized. As a result of examination by the inventors of
the present invention, in a case where the average distance
D.sub.ave between the median points of the two adjacent opening
regions 643 is equal to or longer than 50 .mu.m, and especially, in
a case where the average distance D.sub.ave is equal to or longer
than 70 .mu.m, the light reflected by the side surface of the
connection element 644 is visually recognized by the observer with
high possibility. Therefore, in this case, to prevent that the
light reflected by the side surface of the connection element 644
is visually recognized by the observer, it is especially more
effective that the connection elements for connecting the two
branch points 642 as a straight line segment are less than 20% of
the plurality of connection elements 644. Here, the two adjacent
opening regions 643 are two adjacent opening regions 643 that share
a single connection element 644. As illustrated in FIG. 75, a
distance D between median points G.sub.1 and G.sub.2 is a linear
distance D between the median points G.sub.1 and G.sub.2.
[0551] It is preferable that the average distance D.sub.ave between
the median points of the two adjacent opening regions 643 of the
conductive pattern 640 be equal to or shorter than 800 .mu.m. When
the distance D.sub.ave is equal to or shorter than 800 .mu.m, the
conductive pattern 640 can be effectively made invisible. When the
distance D.sub.ave is equal to or shorter than 300 .mu.m, the
conductive pattern 640 can be more effectively made invisible. It
is considered that human eyes hardly separate and resolve the
opening region 643 of the conductive pattern 640 with such a small
D.sub.ave from the adjacent opening region 643. On the other hand,
it is preferable that the distance D.sub.ave be equal to or longer
than 50 .mu.m. When the distance D.sub.ave is equal to or longer
than 50 .mu.m, an opening rate sufficient for allowing light
passing through the region where the conductive pattern 640 is
arranged can be ensured, and an excellent light transmittance can
be applied to the conductive pattern 640 and the heat-generating
plate 610. When the D.sub.ave is equal to or longer than 50 .mu.m,
for example, when the width W of the connection element is equal to
or less than 5 .mu.m, the light transmission rate of the
heat-generating plate 610 can be equal to or more than 70% as an
example.
[0552] In a case where the average distance D.sub.ave between the
median points of the two adjacent opening regions 643 of the
conductive pattern 640 is equal to or longer than 50 .mu.m and
equal to or shorter than 800 .mu.m, an excellent light
transmittance can be applied to the conductive pattern 640 and the
heat-generating plate 610, and the conductive pattern 640 can be
effectively made invisible. In a case where the average distance
D.sub.ave between the median points of the two adjacent opening
regions 643 of the conductive pattern 640 is equal to or longer
than 50 .mu.m and equal to or shorter than 800 .mu.m, and
especially, in a case where the average distance D.sub.ave is equal
to or longer than 70 .mu.m and equal to or shorter than 800 .mu.m,
by setting the connection elements for connecting two branch points
642 as a straight line segment to be less than 20% of the plurality
of connection elements 644, it can be effectively prevented that
the light reflected by the side surface of the connection element
644 is visually recognized by an observer, and the conductive
pattern 640 can be effectively made invisible. Furthermore, in a
case where the average distance D.sub.ave between the median points
of the two adjacent opening regions 643 of the conductive pattern
640 is equal to or longer than 50 .mu.m and equal to or shorter
than 300 .mu.m, an excellent light transmittance can be applied to
the conductive pattern 640 and the heat-generating plate 610, and
the conductive pattern 640 can be more effectively made invisible.
In addition, in a case where the average distance D.sub.ave between
the median points of the two adjacent opening regions 643 of the
conductive pattern 640 is equal to or longer than 50 .mu.m and
equal to or shorter than 300 .mu.m, and especially, in a case where
the average distance D.sub.ave is equal to or longer than 70 .mu.m
and equal to or shorter than 800 .mu.m, by setting the connection
elements for connecting two branch points 642 as a straight line
segment to be less than 20% of the plurality of connection elements
644, it can be effectively prevented that the light reflected by
the side surface of the connection element 644 is visually
recognized by an observer, and the conductive pattern 640 can be
more effectively made invisible.
[0553] In the example illustrated in FIG. 72, the connection
element 644 includes the first dark color layer 663 provided on the
base material 630, the conductive metal layer 661 provided on the
first dark color layer 663, and the second dark color layer 664
provided on the conductive metal layer 661. In other words, a
surface of the conductive metal layer 661 on the side of the base
material 630 is covered with the first dark color layer 663, and a
surface of the conductive metal layer 661 opposite to the base
material 630 and both side surfaces are covered with the second
dark color layer 664. It is preferable that the dark color layers
663 and 664 be layers having lower reflectance of visible light
than the conductive metal layer 661, for example, the dark color
layers 663 and 664 are layers of dark colors such as black. With
the dark color layers 663 and 664, the conductive metal layer 661
is hardly and visually recognized, and a passenger's visibility is
more preferably secured.
[0554] Next, an example of a manufacturing method for the
heat-generating plate 610 will be described with reference to FIGS.
76 to 82. FIGS. 76 to 82 are cross-sectional views sequentially
illustrating the example of the manufacturing method for the
heat-generating plate 610.
[0555] First, a sheet-like base material 630 is prepared. The base
material 630 is a so-called transparent electrically insulating
resin base material for transmitting light with a wavelength in a
visible light wavelength band (380 nm to 780 nm).
[0556] Next, as illustrated in FIG. 76, a first dark color layer
663 is provided on the base material 630. For example, the first
dark color layer 663 can be provided on the base material 630 by a
plating method including electroplating and electroless plating, a
sputtering method, a CVD method, a PVD method, and an ion plating
method or a method of combination of two or more methods described
above. As a material of the first dark color layer 663, various
known materials can be used. For example, copper nitride, copper
oxide, copper oxynitride, and nickel nitride can be
exemplified.
[0557] Next, as illustrated in FIG. 77, a conductive metal layer
(conductive layer) 61 is provided on the first dark color layer
663. As described above, the conductive metal layer 661 is a layer
formed of one or more of gold, silver, copper, platinum, aluminum,
chromium, molybdenum, nickel, titanium, palladium, indium,
tungsten, and alloys thereof. The conductive metal layer 661 may be
formed by a known method. For example, a method of bonding a metal
foil such as a copper foil with an adhesive having weather
resistance property, a plating method including electroplating and
electroless plating, a sputtering method, a CVD method, a PVD
method, an ion plating method, or a method of combination of two or
more methods described above can be employed.
[0558] In a case where the conductive metal layer 661 is formed of
a metal foil such as a copper foil, the first dark color layer 663
is formed on one surface of the metal foil in advance, and the
metal foil on which the first dark color layer 663 is formed may be
laminated on the base material 630, for example, via an adhesive
layer or a viscosity layer so that the first dark color layer 663
faces to the base material 630. In this case, for example, by
performing darkening processing (blackening processing) on a part
of the material forming the metal foil, the first dark color layer
663 formed of metal oxide or metal sulfide can be formed from a
part of the material that has formed the metal foil Furthermore,
the first dark color layer 663 may be provided on the surface of
the metal foil such as a coating film of a dark color material and
a plating layer of nickel or chromium. In addition, the first dark
color layer 663 may be provided by roughening the surface of the
metal foil.
[0559] Next, as illustrated in FIG. 78, a resist pattern 662 is
provided on the conductive metal layer 661. The resist pattern 662
is a pattern corresponding to the pattern of the conductive pattern
640 to be formed. In the method described here, the resist pattern
662 is provided only on a portion finally forming the conductive
pattern 640. The resist pattern 662 can be formed by patterning
using a known photolithography technique.
[0560] Next, as illustrated in FIG. 79, the conductive metal layer
661 and the first dark color layer 663 are etched using the resist
pattern 662 as a mask. By this etching, the conductive metal layer
661 and the first dark color layer 663 are patterned to
substantially the same pattern as the resist pattern 662. An
etching method is not particularly limited, and a known method can
be employed. As a known method, for example, wet etching using an
etchant and plasma etching can be exemplified. After that, as
illustrated in FIG. 80, the resist pattern 662 is removed.
[0561] Thereafter, as illustrated in FIG. 81, the second dark color
layer 664 is formed on the surface 644b of the conductive metal
layer 661 opposite to the base material 630 and the side surfaces
644c and 644d. For example, by performing darkening processing
(blackening processing) on a part of the material forming the
conductive metal layer 661, the second dark color layer 664 formed
of metal oxide or metal sulfide can be formed from a part of the
conductive metal layer 661. Furthermore, the second dark color
layer 664 may be provided on the surface of the conductive metal
layer 661 as a coating film of a dark color material and a plating
layer of nickel or chromium. In addition, the second dark color
layer 664 may be provided by roughening the surface of the
conductive metal layer 661.
[0562] As described above, the conductive pattern sheet 620
illustrated in FIG. 81 is produced.
[0563] Finally, the glass plate 611, the bonding layer 613, the
conductive pattern sheet 620, the bonding layer 614, and the glass
plate 612 are laminated in this order and heated and pressurized.
In the example illustrated in FIG. 82, first, the bonding layer 613
is temporarily bonded to the glass plate 611, and the bonding layer
614 is temporarily bonded to the glass plate 612. Next, the glass
plate 611 to which the bonding layer 613 is temporarily bonded, the
conductive pattern sheet 620, and the glass plate 612 to which the
bonding layer 614 is temporarily bonded are laminated in this order
and heated and pressurized so that the sides of the glass plates
611 and 612 to which the bonding layers 613 and 614 are
respectively and temporarily bonded face to the conductive pattern
sheet 620. With this structure, the glass plate 611, the conductive
pattern sheet 620, and the glass plate 612 are bonded via the
bonding layers 613 and 614, and the heat-generating plate 610
illustrated in FIG. 72 is manufactured.
[0564] The heat-generating plate 610 according to the present
embodiment described above includes the pair of glass plates 611
and 612, the conductive pattern 640 arranged between the pair of
glass plates 611 and 612 and defining the plurality of opening
regions 643, and the bonding layers 613 and 614 arranged between
the conductive pattern 640 and at least one of the pair of glass
plates 611 and 612, and the conductive pattern 640 includes the
plurality of connection elements 644 extending between the two
branch points 642 and defining the opening region 643, and the
connection elements for connecting the two branch points 642 as a
straight line segment are less than 20% of the plurality of
connection elements 644.
[0565] According to such a heat-generating plate 610, as
illustrated in FIG. 75, light entering the side surface of the
connection element 644 having the shape of a polygonal line, a
curved line segment, and the like other than a straight line
segment is diffusely reflected by the side surface. As a result,
the light entering each point in the side surface of the connection
element 644 from a certain direction can be prevented from being
reflected by the side surface in a certain direction in
correspondence with the incident direction. Therefore, it is
possible to prevent that the reflected light is observed by an
observer and the conductive pattern 640 having the connection
element 644 is visually recognized by the observer.
[0566] Note that various modifications can be made to the
embodiment. Hereinafter, modifications will be described as
appropriately referring to the drawings. In the following
description and the drawings used in the following description,
parts which are similarly formed to those in the embodiments are
denoted with the same reference numerals as those used for
corresponding parts of the embodiment, and overlapped description
will be omitted.
[0567] A modification of a manufacturing method for a
heat-generating plate 610 will be described with reference FIGS. 83
to 87. FIGS. 83 to 87 are cross-sectional views sequentially
illustrating the modification of the manufacturing method for the
heat-generating plate 610.
[0568] First, a conductive pattern sheet 620 is produced. The
conductive pattern sheet 620 can be manufactured by the method
described in the example of the manufacturing method for the
heat-generating plate 610 described above.
[0569] Next, a glass plate 611, a bonding layer 613, and the
conductive pattern sheet 620 are laminated in this order and heated
and pressurized. In the example illustrated in FIG. 83, first, the
bonding layer 613 is temporarily bonded to the glass plate 611.
Next, the glass plate 611 to which the bonding layer 613 is
temporarily bonded is laminated from the side of the conductive
pattern sheet 620 of the conductive pattern 640 and heated and
pressurized so that the side of the glass plate 611 to which the
bonding layer 613 is temporarily bonded faces to the conductive
pattern sheet 620. With this structure, as illustrated in FIG. 84,
the glass plate 611 and the conductive pattern sheet 620 are bonded
to each other (temporarily bonded or completely bonded) via the
bonding layer 613.
[0570] Next, as illustrated in FIG. 85, a base material 630 of the
conductive pattern sheet 620 is removed. For example, when the
conductive pattern sheet 620 is produced, a peeling layer is formed
on the base material 630 in advance, and the conductive pattern 640
is formed on the peeling layer. It is preferable that the peeling
layer be not removed in a process for etching the conductive metal
layer 661 and the first dark color layer 663. In this case, the
base material 630 is bonded to the conductive pattern 640 and the
bonding layer 613 via the peeling layer. Then, in a process for
removing the base material 630 of the conductive pattern sheet 620,
the base material 630 of the conductive pattern sheet 620 is peeled
off from the conductive pattern 640 and the bonding layer 613 by
using the peeling layer.
[0571] As a peeling layer, for example, an interface peeling type
peeling layer, an interlayer peeling type peeling layer, and an
aggregation peeling type peeling layer can be used. As an interface
peeling type peeling layer, a peeling layer having relatively lower
adhesion with the conductive pattern 640 and the bonding layer 613
than the adhesion with the base material 630 can be preferably
used. As such a layer, a silicone resin layer, a fluororesin layer,
and a polyolefin resin layer, and the like can be exemplified. A
peeling layer having relatively lower adhesion with the base
material 630 than the adhesion with the conductive pattern 640 and
the bonding layer 613 can be used. As an interlayer peeling type
peeling layer, a peeling layer including a plurality of layers and
having relatively lower adhesion between the plurality of layers
than the adhesion with the conductive pattern 640, the bonding
layer 613, and the base material 630 can be exemplified. As an
aggregation peeling type peeling layer, a peeling layer in which a
filler as a dispersed phase is dispersed in a base resin as a
continuous phase can be exemplified.
[0572] In a case where an interface peeling type peeling layer
having relatively lower adhesion with the conductive pattern 640
and the bonding layer 613 than the adhesion with the base material
630 is used, the peeling layer is peeled off from the conductive
pattern 640 and the bonding layer 613. In this case, it is possible
to prevent the peeling layer from remaining on the side of the
conductive pattern 640 and the bonding layer 613. That is, the base
material 630 and the peeling layer are removed. When the base
material 630 and the peeling layer are removed, the bonding layer
613 is exposed in an opening region 643 of the conductive pattern
640.
[0573] On the other hand, in a case where an interface peeling type
peeling layer having relatively lower adhesion with the base
material 630 than the adhesion with the conductive pattern 640 and
the bonding layer 613 is used as a peeling layer, the peeling layer
is peeled off from the base material 630. In a case where an
interlayer peeling type peeling layer including a plurality of
layers of films and having relatively lower adhesion between the
plurality of layers than the adhesion with the conductive pattern
640, the bonding layer 613, and the base material 630 is used as a
peeling layer, the plurality of layers is peeled off from each
other. In a case where an aggregation peeling type peeling layer in
which a filler as a dispersed phase is dispersed in a base resin as
a continuous phase is used as a peeling layer, peeling phenomenon
due to cohesive failure in the peeling layer occurs.
[0574] Finally, the glass plate 611, the bonding layer 613, the
conductive pattern 640, the bonding layer 614, and the glass plate
612 are laminated in this order and heated and pressurized. In the
example illustrated in FIG. 86, first, the bonding layer 614 is
temporarily bonded to the glass plate 612. Next, the glass plate
611, the conductive pattern 640, the bonding layer 613, and the
glass plate 612 to which the bonding layer 614 is temporarily
bonded are laminated in this order and heated and pressurized so
that the side of the glass plate 612 to which the bonding layer 614
is temporarily bonded faces to the conductive pattern 640 and the
bonding layer 613. With this structure, the glass plate 611, the
conductive pattern 640, and the glass plate 612 are bonded
(completely bonded) via the bonding layers 613 and 614, and the
heat-generating plate 610 illustrated in FIG. 87 is
manufactured.
[0575] According to the heat-generating plate 610 illustrated in
FIG. 87, it is possible that the heat-generating plate 610 does not
include the base material 630. With this structure, the thickness
of the entire heat-generating plate 610 can be reduced. In
addition, the number of interfaces in the heat-generating plate 610
can be reduced. Therefore, deterioration in optical
characteristics, that is, deterioration in visibility can be
prevented.
[0576] Next, another modification of a manufacturing method for the
heat-generating plate 610 will be described with reference to FIGS.
88 and 89. FIGS. 88 and 89 are cross-sectional views sequentially
illustrating another modification of the manufacturing method for
the heat-generating plate 610.
[0577] First, according to a process similar to that in the
modification of the manufacturing method for the heat-generating
plate 610, a structure in which a glass plate 611 and a conductive
pattern sheet 620 are bonded (temporarily bonded) via a bonding
layer 613 is produced, and a base material 630 is removed from the
structure. That is, a laminate, in which the glass plate 611, the
conductive pattern 640, and the bonding layer 613 are laminated,
described in the modification of the manufacturing method for the
heat-generating plate 610 with reference to FIG. 85 is
obtained.
[0578] Next, as illustrated in FIG. 88, the glass plate 611, the
bonding layer 613, the conductive pattern 640, and the glass plate
612 are laminated in this order and heated and pressurized. As a
result, the glass plate 611 is bonded (completely bonded) to the
conductive pattern 640 via the bonding layer 613, and the glass
plate 611 is bonded (completely bonded) to the glass plate 612 via
the bonding layer 613. Then, the heat-generating plate 610
illustrated in FIG. 89 is manufactured.
[0579] According to the heat-generating plate 610 illustrated in
FIG. 89, it is possible that the heat-generating plate 610 does not
include the base material 630 and the bonding layer 614. With this
structure, the thickness of the entire heat-generating plate 610
can be more reduced. In addition, the number of interfaces in the
heat-generating plate 610 can be more reduced. Therefore,
deterioration in optical characteristics, that is, deterioration in
visibility can be more effectively prevented. In addition, since
the conductive pattern 640 has contact with the glass plate 612, a
heating efficiency of the glass plate 612 by the conductive pattern
640 can be enhanced.
[0580] As another modification, FIG. 90 illustrates a modification
of a reference pattern. As illustrated in FIG. 90, a reference
pattern 750 is a mesh pattern defining a large number of opening
regions 753. The reference pattern 750 includes a plurality of line
segments 754 extending between the two branch points 752 and
defining the opening regions 753. That is, the reference pattern
750 is formed as a group of a large number of line segments 754
forming the branch points 752 at both ends. Especially, in the
illustrated example, the reference pattern 750 has a shape obtained
by extending the reference pattern 650 illustrated in FIG. 73 along
a first direction (X), in other words, a shape obtained by
compressing the reference pattern 650 illustrated in FIG. 73 along
a second direction (Y) perpendicular to the first direction
(X).
[0581] A part of the conductive pattern 740 determined by the
method described with reference to FIG. 74 based on the reference
pattern 750 is enlarged and illustrated in FIG. 91 together with a
part of the corresponding reference pattern 750. In the example
illustrated in FIG. 91, the conductive pattern 740 includes the
plurality of branch points 742 arranged on each branch point 752 of
the reference pattern 750, and the plurality of connection elements
744 extending between the two branch points 742 and defining the
opening region 743, and the connection elements for connecting two
branch points 742 as straight line segments are less than 20% of
the plurality of connection elements 744. The conductive pattern
740 has a mesh pattern in which the connection elements 744 are
arranged in correspondence with the respective line segments 754 of
the reference pattern 750.
[0582] In the example illustrated in FIG. 91, an average of a ratio
(L.sub.1/L.sub.2) of a length L.sub.1 of each opening region 743 of
the conductive pattern 740 along the first direction (X) relative
to a length L.sub.2 of the opening region 743 along the second
direction (Y) perpendicular to the first direction (X) is equal to
or more than 1.3 and equal to or less than 1.8. In a case where the
conductive pattern 740 includes the opening region 743 having such
a size, a possibility such that light reflected by the side surface
of the connection element 744 is visually recognized by an observer
is increased. Therefore, in this case, to prevent that the light
reflected by the side surface of the connection element 744 is
visually recognized by the observer, it is especially more
effective that the connection elements for connecting the two
branch points 742 as a straight line segment are less than 20% of
the plurality of connection elements 744.
[0583] Each size of the conductive patterns 640 and 740 such as the
average distance D.sub.ave between the median points of the two
adjacent opening regions 643 and the average of the ratio
(L.sub.1/L.sub.2) of the length L.sub.1 of each opening region 743
of the conductive pattern 740 along the first direction (X)
relative to the length L.sub.2 of the opening region 743 along the
second direction (Y) perpendicular to the first direction (X) are
not necessarily specified by examining the entire regions of the
conductive patterns 640 and 740 and calculating average values. In
actual, in a single section having an area which is expected to
reflect overall tendencies of values to be examined (the average
distance D.sub.ave between the median points of the two adjacent
opening regions 643 and the average of the ratio (L.sub.1/L.sub.2)
of the length L.sub.1 of each opening region 743 of the conductive
pattern 740 along the first direction (X) relative to the length
L.sub.2 of the opening region 743 along the second direction (Y)
perpendicular to the first direction (X)), each size can be
calculated and specified by examining an appropriate number of
targets in consideration of variation in the numbers to be
examined. The values specified in this way are respectively used as
the average distance D.sub.ave between the median points of the two
adjacent opening regions 643 and the average of the ratio
(L.sub.1/L.sub.2) of the length L.sub.1 of each opening region 743
of the conductive pattern 740 along the first direction (X)
relative to the length L.sub.2 of the opening region 743 along the
second direction (Y) perpendicular to the first direction (X). In
the conductive patterns 640 and 740 according to the present
embodiment, by measuring 100 points included in the region of 300
mm.times.300 mm by an optical microscope or an electron microscope
and calculating an average, the sizes of the conductive patterns
640 and 740 can be specified.
[0584] As another modification, in the embodiment described above,
the conductive patterns 640 and 740 have a pattern determined based
on the Voronoi diagram generated from sites randomly distributed in
a planar surface, that is, in which a large number of opening
regions 653 and 753 are arranged with shapes and pitches with no
repeating regularity (periodic regularity). However, the pattern is
not limited to this, and patterns such as a pattern in which
opening regions having the same shapes such as a triangle, a
rectangle, and a hexagon are regularly arranged, a pattern in which
opening region having different shapes are regularly arranged may
be used.
[0585] In the examples illustrated in FIGS. 76 to 89, the second
dark color layer 664 forms the surface 644b opposite to the base
material 630 of the connection element 644 and the side surfaces
644c and 644d. However, the modification is not limited to this,
and the second dark color layer 664 may form only the surface 644b
opposite to the base material 630 of the connection element 644 or
only the side surfaces 644c and 644d of the connection element 644.
In a case where the second dark color layer 664 forms only the
surface 644b opposite to the base material 630 of the connection
element 644, for example, after the process illustrated in FIG. 77,
the second dark color layer 664 and the resist pattern 662 are
provided on the conductive metal layer (conductive layer) 661 in
this order. Thereafter, it is preferable that the second dark color
layer 664, the conductive metal layer 661, and the first dark color
layer 663 be etched by using the resist pattern 662 as a mask. In a
case where the second dark color layer 664 forms only the side
surfaces 644c and 644d of the connection element 644, for example,
after the process illustrated in FIG. 79, the second dark color
layer 664 is formed without removing the resist pattern 662, and
the resist pattern 662 may be removed after that. In a case where
it is not necessary to provide the first dark color layer 663, the
process for providing the first dark color layer 663 on the base
material 630 illustrated in FIG. 76 may be omitted.
[0586] The heat-generating plate 610 may be used for a rear window,
a side window, or a sunroof of an automobile 601. In addition, the
heat-generating plate 610 may be used for a window or a door of a
vehicle, such as a railway vehicle, an aircraft, a ship, and a
spacecraft, other than an automobile.
[0587] In addition to vehicles, the heat-generating plate 610 can
be used for a window or a door of a building such as a shop and a
house, especially in a place where indoor and outdoor is divided, a
window material (cover or protection glass plate) of various
traffic lights, a window material of a headlamp of various
vehicles, and the like.
[0588] Although some modifications regarding the embodiment have
been described above, naturally, a plurality of modifications can
be appropriately combined and applied.
EXAMPLES
[0589] Hereinafter, although the present invention will be
described in more detail with reference to examples, the present
invention is not limited to the examples.
Example 4
[0590] A laminated glass in Example 4 is produced as follows.
First, as a base material 630, a biaxially stretched polyethylene
terephthalate (PET) film (manufactured by TOYOBO CO., LTD. A4300)
with the thickness of 100 .mu.m, the width of 98 cm, and the length
of 100 m is prepared. A two-liquid mixed curable type urethane
ester type adhesive is laminated on the base material 630 by a
gravure coater so that a dried thickness of the laminate at the
time when the laminate is cured is 7 .mu.m. Then, an electrolytic
copper foil with the thickness of 3 .mu.m, the width of 97 cm, and
the length of 80 m is laminated as the conductive metal layer 661
on the base material 630 via adhesive, and this state is maintained
for four days under an environment with an ambient temperature of
50.degree. C., and the electrolytic copper foil is fixed to the
base material 630.
[0591] Thereafter, a layer of a photosensitivity resist material is
laminated on the electrolytic copper foil (conductive metal layer
661) with a mercury lamp via a photomask having a pattern including
the plurality of connection elements determined based on the
reference pattern 650 having a large number of opening regions 653
arranged so as to coincide with the Voronoi regions in the Voronoi
diagram generated from the sites of which the distance between the
adjacent sites are randomly distributed between the predetermined
upper limit and the predetermined lower limit in the planar surface
described with reference to FIGS. 73 and 74. Then, the resist
pattern 662 is formed by cleaning (removing) an extra
photosensitivity resist material, and the electrolytic copper foil
is etched by using corrosive liquid of aqueous ferric chloride
solution using the resist pattern 662 as a mask. Then, the resist
pattern 662 is cleaned with pure water and the remaining resist
pattern 662 is removed so as to obtain the conductive pattern sheet
620 having the conductive pattern 640 including the plurality of
connection elements 644 determined based on the reference pattern
650 having a large number of opening regions 653 arranged so as to
coincide with the Voronoi regions in the Voronoi diagram. In the
conductive pattern sheet 620, the width W of the connection element
644 of the conductive pattern 640 is 7 .mu.m, and the height
(thickness) of the connection element 644, that is, the height
(thickness) H of the conductive pattern 640 is 3 .mu.m. The ratio
of the connection elements 644 for connecting the two branch points
642 of the conductive pattern 640 as a straight line segment
relative to the all of the connection elements 644 is 15%. The
average distance D.sub.ave between the median points of the two
adjacent opening regions 643 of the conductive pattern 640 is 50
.mu.m. The ratio of the connection elements 644 for connecting the
two branch points 642 of the conductive pattern 640 as a straight
line segment relative to all the connection elements 644 is
specified by observing 100 points in the region of 300 mm.times.300
mm in the conductive pattern 640 with an optical microscope.
[0592] Then, the conductive pattern sheet 620 obtained as described
above is cut into a substantially trapezoidal shape having an upper
base of 125 cm, a bottom base of 155 cm, and a height of 96 cm.
Then, the conductive pattern sheet 620 is arranged between the
substantially trapezoidal glass plates 611 and 612 having the shape
and the size with the upper base of 120 cm, and the lower base of
150 cm, and the height of 95 cm in a case of being observed from
the normal direction of the surfaces (pair of surface having the
largest area) via the bonding layers 613 and 614 including a PVB
adhesive sheet having the same as the glass plates 611 and 612.
Then, the laminate is heated and pressurized (vacuum lamination).
Then, the bonding layers 613 and 614 and the conductive pattern
sheet 620 protruding from the peripheries of the glass plates 611
and 612 are trimmed, and the heat-generating plate 610 in Example 4
is obtained.
[0593] When the heat-generating plate 610 according to Example 4 is
visually checked, the conductive pattern 640 is not visually
recognized at a distance of 60 cm from the heat-generating plate
610. Furthermore, the conductive pattern 640 cannot be visually
recognized at a distance equal to or more than 60 cm. As a result,
it can be confirmed that the conductive pattern 640 of the
heat-generating plate 610 according to Example 4 is sufficiently
invisible. A light transmittance of the heat-generating plate 610
according to Example 4 is evaluated as an average value of a light
transmittance rate in a measurement wavelength of 380 nm to 780 nm.
When the light transmittance is measured by a spectrophotometer
("UV-3100PC" manufactured by SHIMADZU CORPORATION, conforming to
JIS K 0115), the light transmission rate is 71%. As a result, it is
confirmed that the heat-generating plate 610 of Example 4 has a
sufficient light transmittance.
(Example 5) to (Example 9) and (Comparative Example
[0594] 3) to (Comparative Example 5)
[0595] A heat-generating plates 610 according to Examples 5 to 9
and Comparative Examples 3 to 5 are produced by a process similar
to that of the heat-generating plate 610 of Example 4, and the
obtained heat-generating plate 610 is similar to the
heat-generating plate 610 according to Example 4 except that the
average distance D.sub.ave between the median points of the two
adjacent opening regions 643 of the conductive pattern 640 and the
width W of the connection element 644 are changed as indicated in
Table 2.
[0596] Table 2 collectively indicates the average distance
D.sub.ave between the median points of the two adjacent opening
regions 643 of the conductive pattern 640, the width W of the
connection element 644 of the conductive pattern 640, invisibility
of the conductive pattern 640 in visual recognition, the light
transmittance of the heat-generating plate 610, and the light
transmittance rate of the heat-generating plate 610 in Examples 4
to 9 and Comparative Examples 3 to 5. The invisibility of the
conductive pattern 640 in visual recognition is indicated in a
column of "invisibility" in Table 2 as A, B, and C. In the column
of "invisibility", A indicates that the conductive pattern 640 is
not visually recognized at a distance of 60 cm from the
heat-generating plate 610, B indicates that the conductive pattern
640 is visually recognized at a distance of 60 cm from the
heat-generating plate 610 and is not visually recognized at a
distance of 80 cm from the heat-generating plate 610, and C
indicates that the conductive pattern 640 is visually recognized at
a distance of 80 cm from the heat-generating plate 610. The light
transmittance of the heat-generating plate 610 is indicated by B
and C in the column of "light transmittance" in Table 2. B
indicates that the light transmittance of the heat-generating plate
610 is equal to or more than 70%, and C indicates that the light
transmittance of the heat-generating plate 610 is less than
70%.
[0597] From Table 2, it is found that excellent invisibility of the
conductive pattern 640 and an excellent light transmittance of the
heat-generating plate 610 can be both achieved in a case where the
width W of the connection element 644 is equal to or more than 1
.mu.m and equal to or less than 7 .mu.m in Examples 4 to 9 in which
the average distance D.sub.ave is equal to or more than 50 .mu.m
and equal to or less than 800 .mu.m in comparison with Comparative
Examples 3 to 5 in which the average distance D.sub.ave is equal to
or more than 50 .mu.m and equal to or less than 800 .mu.m.
Furthermore, it can be found that more excellent invisibility of
the conductive pattern 640 and more excellent light transmittance
of the heat-generating plate 610 can be both achieved in Examples 4
to 7 in which the average distance D.sub.ave is equal to or more
than 50 .mu.m and equal to or less than 150 .mu.m in comparison
with Examples 8 and 9.
TABLE-US-00002 TABLE 2 COMPAR- COMPAR- COMPAR- ATIVE ATIVE ATIVE
EXAMPLE EXAMPLE EXAMPLE EXAMPLE EXAMPLE EXAMPLE EXAMPLE EXAMPLE
EXAMPLE 4 5 6 7 8 9 3 4 5 D.sub.ave 50 50 100 300 600 600 30 1000
1000 (.mu.m) W 7 1 5 5 1 7 7 1 7 (.mu.m) INVISI- A A A A B B B C C
BILITY LIGHT 71 86 81 84 89 86 53 90 88 TRANS- MISSION RATE (%)
LIGHT B B B B B B C B B TRANS- MITTANCE
* * * * *