U.S. patent application number 14/232460 was filed with the patent office on 2014-06-19 for touch panel comprising conductive pattern.
The applicant listed for this patent is LG CHEM, LTD.. Invention is credited to Hyeon Choi, In-Seok Hwang, Ji Young Hwang, Seung Heon Lee.
Application Number | 20140168543 14/232460 |
Document ID | / |
Family ID | 47996622 |
Filed Date | 2014-06-19 |
United States Patent
Application |
20140168543 |
Kind Code |
A1 |
Hwang; Ji Young ; et
al. |
June 19, 2014 |
TOUCH PANEL COMPRISING CONDUCTIVE PATTERN
Abstract
The present invention relates to a touch panel comprising a
conductive pattern having improved transmittance and concealing
property, and the touch panel according to the present invention
can have an effect of improvement in transmittance, a concealing
property, and uniformity, and a reduction in strength of a
diffraction pattern by reflection light in a conductive pattern by
providing the conductive patterns comprising regions having
different aperture ratios on both surfaces of a transparent
substrate at predetermined positions, or laminating the transparent
substrate having the conductive patterns comprising the regions
having different aperture ratios.
Inventors: |
Hwang; Ji Young; (Daejeon,
KR) ; Hwang; In-Seok; (Daejeon, KR) ; Choi;
Hyeon; (Daejeon, KR) ; Lee; Seung Heon;
(Daejeon, KR) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
LG CHEM, LTD. |
Seoul |
|
KR |
|
|
Family ID: |
47996622 |
Appl. No.: |
14/232460 |
Filed: |
September 27, 2012 |
PCT Filed: |
September 27, 2012 |
PCT NO: |
PCT/KR2012/007800 |
371 Date: |
January 13, 2014 |
Current U.S.
Class: |
349/12 |
Current CPC
Class: |
G06F 3/041 20130101;
G06F 2203/04111 20130101; G06F 2203/04103 20130101 |
Class at
Publication: |
349/12 |
International
Class: |
G06F 3/041 20060101
G06F003/041 |
Foreign Application Data
Date |
Code |
Application Number |
Sep 27, 2011 |
KR |
10-2011-0097753 |
Claims
1. A touch panel comprising: a first conductive substrate
comprising a first transparent substrate and a first conductive
pattern provided on the first transparent substrate, and a second
conductive substrate comprising a second transparent substrate and
a second conductive pattern provided on the second transparent
substrate in a laminate form, wherein the first conductive pattern
comprises regions A and B having different aperture ratios having a
difference of 0.5% or more therebetween, the second conductive
pattern comprises region C overlapping the region A and region D
overlapping the region B, and a difference between a product of the
aperture ratio of the region A and the aperture ratio of the region
C and a product of the aperture ratio of the region B and the
aperture ratio of the region D is 2% or less.
2. A touch panel comprising: a transparent substrate, a first
conductive pattern provided on one surface of the transparent
substrate, and a second conductive pattern provided on the other
surface of the transparent substrate, wherein the first conductive
pattern comprises regions A and B having different aperture ratios
having a difference of 0.5% or more therebetween, the second
conductive pattern comprises region C overlapping the region A and
region D overlapping the region B, and a difference between a
product of the aperture ratio of the region A and the aperture
ratio of the region C and a product of the aperture ratio of the
region B and the aperture ratio of the region D is 2% or less.
3. The touch panel of claim 1, wherein the aperture ratios of the
region A and the region B are different from each other by 1.5% or
more, and the difference between the product of the aperture ratio
of the region A and the aperture ratio of the region C and the
product of the aperture ratio of the region B and the aperture
ratio of the region D is 0.5% or less.
4. The touch panel of claim 1, wherein the first conductive pattern
further comprises region AB, and the region AB is provided between
the region A and the region B, and has an aperture ratio between
the aperture ratio of the region A and the aperture ratio of the
region B.
5. The touch panel of claim 4, wherein the second conductive
pattern further comprises region CD, and the region CD is provided
between the region C and the region D, overlaps the region AB, and
has an aperture ratio between the aperture ratio of the region C
and the aperture ratio of the region D.
6. The touch panel of claim 4, wherein the difference between the
product of the aperture ratio of the region AB and the aperture
ratio of the region CD and the product of the aperture ratio of the
region A and the aperture ratio of the region C is 1% or less.
7. The touch panel of claim 4, wherein the difference between the
product of the aperture ratio of the region AB and the aperture
ratio of the region CD and the product of the aperture ratio of the
region B and the aperture ratio of the region D is 1% or less.
8. The touch panel of claim 1, wherein the region A and the region
B of the first conductive pattern and the region C and the region D
of the second conductive pattern each comprise an effective screen
portion of the touch panel, and 90% or more of the effective screen
portion of the touch panel has an aperture ratio deviation of 1% or
less.
9. The touch panel of claim 4, wherein the region A, the region B,
and the region AB of the first conductive pattern and the region C,
the region D, and the region CD of the second conductive pattern
each comprise the effective screen portion of the touch panel, and
90% or more of the effective screen portion of the touch panel has
the aperture ratio deviation of 1% or less.
10. The touch panel of claim 1, wherein a surface resistance
difference between the region A and the region B of the first
conductive pattern is 20% or less.
11. The touch panel of claim 1, wherein the surface resistance
difference between the region C and the region D of the second
conductive pattern is 20% or less.
12. The touch panel of claim 1, wherein the first conductive
pattern and the second conductive pattern comprise a pattern formed
of a conductive metal line.
13. The touch panel of claim 12, wherein the pattern formed of the
conductive metal line comprises a closed curve formed of a straight
line, a curved line, or the straight line and the curved line.
14. The touch panel of claim 1, wherein the first conductive
pattern and the second conductive pattern comprise a regular or
irregular pattern.
15. The touch panel of claim 1, wherein the first conductive
pattern and the second conductive pattern comprise a mesh
pattern.
16. The touch panel of claim 15, wherein the region A and the
region D have different mesh rotational angles.
17. The touch panel of claim 1, wherein the first conductive
pattern and the second conductive pattern comprise an edge
structure of continuously connected closed figures, the closed
figures having the same shape are not present in a predetermined
unit area (1 cm.times.1 cm) in the first conductive pattern and the
second conductive pattern, and the number of vertexes of the closed
figures is different from the number of vertexes of quadrangles
having the same number as the closed figures.
18. The touch panel of claim 1, wherein the first conductive
pattern and the second conductive pattern comprise the edge
structure of continuously connected closed figures, the closed
figures having the same shape are not present in a predetermined
unit area (1 cm.times.1 cm) in the first conductive pattern and the
second conductive pattern, and the number of vertexes of the closed
figures is different from the number of vertexes of a polygon
formed by connecting shortest distances between centers of gravity
of the closed figures.
19. The touch panel of claim 1, wherein the first conductive
pattern and the second conductive pattern comprise the edge
structure of continuously connected closed figures, the closed
figures having the same shape are not present in a predetermined
unit area (1 cm.times.1 cm) in the first conductive pattern and the
second conductive pattern, and a value of the following Equation 1
is 50 or more in the closed figures: (Standard deviation of
distances between the vertexes/Average of the distances between the
vertexes).times.100. [Equation 1]
Description
[0001] This application claims priority from Korean Patent
Application No. 10-2011-0097753 filed on Sep. 27, 2011, in the
KIPO, the disclosure of which is incorporated herein by reference
in its entirety.
TECHNICAL FIELD
[0002] The present invention relates to a touch panel comprising a
conductive pattern.
BACKGROUND ART
[0003] In general, a display device refers to monitors for a TV or
a computer as a whole, and comprises a display device forming an
image and a case supporting the display device.
[0004] Examples of the display device may comprise a plasma display
panel (PDP), a liquid crystal display (LCD), an electrophoretic
display, and a cathode-ray tube (CRT). An RGB pixel pattern for
implementing an image and an additional optical filter may be
provided in the display device.
[0005] The optical filter may comprise at least one of a reflection
prevention film preventing the light that is incident from the
outside from being reflected to the outside, a near IR shield film
shielding the near IR generated in the display device in order to
prevent mis-operation of electronic devices such as remote
controllers, a color correction film increasing the color purity by
controlling a color tone by comprising a color control dye, and an
electromagnetic wave shield film shielding the electromagnetic wave
generated in a display device when a display apparatus is driven.
Here, the electromagnetic wave shield film comprises a transparent
substrate and a metal mesh pattern provided on the substrate.
[0006] Meanwhile, with regard to the display apparatus, as the
spread of IPTVs is accelerated, a demand for a touch function that
uses hands as a direct input apparatus without a separate input
apparatus such as remote controllers is growing. In addition, a
multi-touch function for recognizing a specific point and taking
notes is required.
[0007] The touch panel performing the aforementioned function may
be classified into the following types according to detection
manner of a signal.
[0008] That is, examples thereof comprise a resistive type
detecting a position pressed by pressure in a state where a direct
voltage is applied while changing a current or voltage value, a
capacitive type using capacitance coupling in a state where an
alternating voltage is applied, an electromagnetic type detecting a
selected position in a state where a magnetic field is applied as a
change in voltage, and the like.
[0009] Among them, the resistive type and capacitive type touch
panels that are most extensively spread recognize the touch by a
change in electric contact or capacitance by using the transparent
conductive film such as the ITO film. However, since the
transparent conductive film has high resistance of 100 ohms/square
or more, the sensitivity is lowered when the display device is
manufactured in a large scale, and as the size of screen is
increased, the cost of the ITO film is rapidly increased,
accordingly, it is not easy to perform commercialization thereof.
In order to overcome this, there is an effort to implement
enlargement by using a metal pattern having high conductivity.
[0010] In the case of a known transparent conductor comprising ITO
and a transparent conductor comprising a conductive pattern and a
metal line, a dummy pattern for implementing uniform transmittance
on one surface has been introduced, precise alignment and
lamination of a metal line, a metal line between constitutional
elements of each touch panel have been ensured, or the transparent
conductive film on the one surface, in which line breakage is
introduced within a predetermined ratio, has been implemented in
order to overcome a problem of visibility according to a
transmittance difference of a transparent conductive film
constituting a touch panel. However, this method has problems in
that a loss of transmittance occurs due to the presence of an
additional region not providing a large electric affection, it is
difficult to ensure precision of alignment in the case where a fine
line is introduced (10 .mu.m or less and the like), and
transmittance is reduced when two transparent conductive films are
laminated by maintaining a predetermined pitch and closing ratio on
the one surface in order to ensure uniformity of the one
surface.
DISCLOSURE
Technical Problem
[0011] Therefore, the present invention has been made in an effort
to maximize transmittance, a concealing property, uniformity, and
the like of a conductive pattern, thus improving the transmittance,
the concealing property, the uniformity, and the like of a touch
panel comprising the same.
Technical Solution
[0012] An exemplary embodiment of the present invention provides a
touch panel comprising: a first conductive substrate comprising a
first transparent substrate and a first conductive pattern provided
on the first transparent substrate, and a second conductive
substrate comprising a second transparent substrate and a second
conductive pattern provided on the second transparent substrate in
a laminate form, wherein the first conductive pattern comprises
regions A and B having different aperture ratios having a
difference of 0.5% or more therebetween, the second conductive
pattern comprises region C overlapping the region A and region D
overlapping the region B, and a difference between a product of the
aperture ratio of the region A and the aperture ratio of the region
C and a product of the aperture ratio of the region B and the
aperture ratio of the region D is 2% or less.
[0013] Another exemplary embodiment of the present invention
provides a touch panel comprising: a transparent substrate, a first
conductive pattern provided on one surface of the transparent
substrate, and a second conductive pattern provided on the other
surface of the transparent substrate, wherein the first conductive
pattern comprises regions A and B having different aperture ratios
having a difference of 0.5% or more therebetween, the second
conductive pattern comprises region C overlapping the region A and
region D overlapping the region B, and a difference between a
product of the aperture ratio of the region A and the aperture
ratio of the region C and a product of the aperture ratio of the
region B and the aperture ratio of the region D is 2% or less.
Advantageous Effects
[0014] A touch panel according to the present invention can have an
effect of improvement in transmittance, a concealing property, and
uniformity, and a reduction in strength of a diffraction pattern by
reflection light of a conductive pattern by providing the
conductive patterns comprising regions having different aperture
ratios on both surfaces of a transparent substrate at predetermined
positions, or laminating the transparent substrate having the
conductive patterns comprising the regions having different
aperture ratios.
BRIEF DESCRIPTION OF THE DRAWINGS
[0015] FIG. 1 is an exemplary embodiment of the present invention,
and is a view showing a first conductive substrate, a second
conductive substrate, and a touch panel comprising the first
conductive substrate and the second conductive substrate in a
lamination form.
[0016] FIG. 2 is the exemplary embodiment of the present invention,
and is a view showing conductive patterns in the case where
electric uniformity is not considered and in the case where
electric uniformity is ensured through line breakage of cross
points.
[0017] FIG. 3 is the exemplary embodiment of the present invention,
and is a view showing aperture ratios for positions and a sum of
the aperture ratios in the case where the conductive patterns are
unilaterally divided according to a region and in the case where an
additional region having another aperture ratio between regions
having different aperture ratios is provided.
[0018] FIG. 4 is the exemplary embodiment of the present invention,
and is a view showing the sum of the aperture ratios by lamination
tolerance according to the position in the case where the
conductive patterns are unilaterally divided according to the
region.
[0019] FIG. 5 is the exemplary embodiment of the present invention,
and is a view showing the sum of the aperture ratios by lamination
tolerance according to the position in the case where the
additional region having another aperture ratio between regions
having different aperture ratios in the conductive pattern is
provided.
[0020] FIG. 6 is the exemplary embodiment of the present invention,
and is a view showing the aperture ratio for the shape and the
position of the conductive pattern in the case where the additional
region having another aperture ratio between the regions having the
different aperture ratios in the conductive pattern is
provided.
[0021] FIG. 7 is the exemplary embodiment of the present invention,
and is a view showing the a difference between the areas of the
additional region according to a total reflection condition when
the additional region having another aperture ratio between the
regions having the different aperture ratios in the conductive
pattern is provided in the case where reinforced glass is attached
and in the case where reinforced glass is not attached.
[0022] FIGS. 8 and 9 are the exemplary embodiment of the present
invention, and views showing examples of division of the region of
the conductive pattern.
BEST MODE
[0023] Hereinafter, the present invention will be described in
detail.
[0024] An exemplary embodiment of a touch panel according to the
present invention comprises: a first conductive substrate
comprising a first transparent substrate and a first conductive
pattern provided on the first transparent substrate, and a second
conductive substrate comprising a second transparent substrate and
a second conductive pattern provided on the second transparent
substrate in a laminate form, wherein the first conductive pattern
comprises regions A and B having different aperture ratios having a
difference of 0.5% or more therebetween, the second conductive
pattern comprises region C overlapping the region A and region D
overlapping the region B, and a difference between a product of the
aperture ratio of the region A and the aperture ratio of the region
C and a product of the aperture ratio of the region B and the
aperture ratio of the region D is 2% or less.
[0025] Another exemplary embodiment of a touch panel according to
the present invention comprises: a transparent substrate, a first
conductive pattern provided on one surface of the transparent
substrate, and a second conductive pattern provided on the other
surface of the transparent substrate, wherein the first conductive
pattern comprises regions A and B having different aperture ratios
having a difference of 0.5% or more therebetween, the second
conductive pattern comprises region C overlapping the region A and
region D overlapping the region B, and a difference between a
product of the aperture ratio of the region A and the aperture
ratio of the region C and a product of the aperture ratio of the
region B and the aperture ratio of the region D is 2% or less.
[0026] The present invention has focused uniformity and
transmittance of the touch panel manufactured in practice unlike a
known method in order to solve the aforementioned problems.
Therefore, in the present invention, in views of a user, when the
patterns like FIG. 1 are introduced on upper and lower surfaces
constituting the touch panel or both surfaces of the transparent
substrate and then laminated, a pattern is designed so that uniform
and high transmittance is exhibited in order to ensure uniformity
and transmittance. The designing and introduction of the pattern of
this method are different from a known invention in that the
patterns are positioned to be separated from each other on
different layers based on transmittance and uniformity of the touch
panel or uniformity of transmittance is adjusted through addition
of the pattern unlike a known method of maintaining constitution
and transmittance of an electric circuit through line breakage of a
pattern.
[0027] FIG. 1 shows a view of the touch panel having a mesh shape,
to which the present invention is applied. The present invention
mainly describes that when the touch panel is constituted,
different layers (different surfaces of a single layer) are
introduced into the mutually reflected pattern like FIG. 1 in order
to improve transmittance, uniformity, and transmittance, and is
advantageous in that when the touch panel is constituted through a
lamination process and the like, a uniform resulting matter having
improved transmittance can be finally obtained. In this case, in
the case where the regular patterns are introduced into different
surfaces, it is preferable that an angle of the mesh be 45.degree.
for both sides in order to avoid a moire.
[0028] That is, in the touch panel according to the present
invention, when the first conductive pattern and the second
conductive pattern are laminated, since one mesh pattern is formed,
the same mesh rotational angle may be ensured.
[0029] The present invention may be applied to areas of various
sizes in any region in the touch panel as well as the form like
FIG. 1, and in this case, overall uniformity and transmittance of
the finally manufactured touch panel may be ensured, and the
present invention does not largely affect any pitch having a
predetermined size.
[0030] Another factor that may be considered in the present
invention is uniformity of resistances. In view of uniformity of
resistances, the pattern having the shape like FIG. 2 can be
designed by more developing the shape like FIG. 1, and in the case
where this method is used, all of the overall resistance
uniformity, pattern uniformity, and transmittance may be satisfied.
To be more specific, FIG. 2 is an example, to which a line breakage
method of an irregular pattern is applied, and is a view showing a
pattern in the case where electric uniformity is not considered and
a pattern in the case where electric uniformity is ensured through
line breakage of cross points.
[0031] In the touch panel according to the present invention, the
difference between the aperture ratios of region A and region B may
be 0.5% or more, 0.75% or more, 1% or more, 1.25% or more, and 1.5%
or more.
[0032] In the touch panel according to the present invention, the
difference between the product of the aperture ratio of region A
and the aperture ratio of region C and the product of the aperture
ratio of region B and the aperture ratio of region D may be 2% or
less, 1% or less, and 0.5% or less.
[0033] Particularly, the aperture ratios of region A and region B
may be different from each other by 1.5% or more, and the
difference between the product of the aperture ratio of region A
and the aperture ratio of region C and the product of the aperture
ratio of region B and the aperture ratio of region D may be 0.5% or
less.
[0034] Another factor that may be considered in the present
invention is that region AB and region CD that are a pattern design
region for maximally concealing a boundary portion of the patterns
when the patterns present on two different surfaces are laminated
may be comprised in different surfaces. To this end, in the present
invention, region AB and region CD that are an additional pattern
region for minimizing a deviation between the aperture ratios like
a lower portion of FIG. 3 may be introduced. FIG. 3 shows a sum of
the aperture ratios when lamination is precisely performed without
an error in the case where the pattern is unilaterally divided
according to the region and in the case where an aperture ratio
gradient is provided by providing region AB and region CD that are
the additional pattern region for concealing the boundary
portion.
[0035] As confirmed from FIG. 3, in the case where the precise
lamination is performed, the case where the additional region is
not provided may exhibit the relatively more uniform aperture
ratio. However, in general, the lamination process is a process
comprising a process error of several to several tens micrometers
between processes, and in the case where lamination tolerance
occurs, as shown in FIGS. 4 and 5 in two aforementioned cases, a
shift of a graph of the aperture ratio for position occurs, thus,
the graph of the sum of the aperture ratios is shown like a right
portion thereof. In the two cases, referring to the graph of the
sum of the aperture ratios, in the case where the aperture ratio
gradient is not provided, a region exhibiting a relatively steep
difference between the aperture ratios is present, thus causing
recognition of the boundary to allow persons to recognize the
boundary region. On the other hand, in the case where the aperture
ratio gradient is provided, since the aperture ratio is gradually
increased and reduced, definition of the boundary is not largely
exhibited, which is a better method in view of concealing of the
boundary.
[0036] That is, in the touch panel according to the present
invention, the aperture ratios of region AB and region CD that are
the region between region A and region B and the region between
region C and region D, respectively, may each have a value between
the aperture ratios of two regions. Further, the aperture ratio of
the interfacial region may have a gradient gradually changed in a
direction from any one region to another region.
[0037] In the touch panel according to the present invention, the
first conductive pattern further comprises region AB, and region AB
may be provided between region A and region B and have an aperture
ratio between the aperture ratio of region A and the aperture ratio
of region B.
[0038] In the touch panel according to the present invention, the
second conductive pattern further comprises region CD, and region
CD may be provided between region C and region D, overlap region
AB, and have an aperture ratio between the aperture ratio of region
C and the aperture ratio of region D.
[0039] A difference between a product of the aperture ratio of
region AB and the aperture ratio of region CD and a product of the
aperture ratio of region A and the aperture ratio of region C may
be 1% or less and is preferably 0.5% or less, but is not limited
thereto.
[0040] A difference between a product of the aperture ratio of
region AB and the aperture ratio of region CD and a product of the
aperture ratio of region B and the aperture ratio of region D may
be 1% or less and is preferably 0.5% or less, but is not limited
thereto.
[0041] Region A and region B of the first conductive pattern, and
region C and region D of the second conductive pattern each
comprise an effective screen portion of the touch panel, and 90% or
more of the effective screen portion of the touch panel may have an
aperture ratio deviation of 1% or less, and has preferably the
aperture ratio deviation of 0.5% or less, but the aperture ratio
deviation is not limited thereto.
[0042] Region A, region B, and region AB of the first conductive
pattern, and region C, region D, and region CD of the second
conductive pattern each comprise the effective screen portion of
the touch panel, and 90% or more of the effective screen portion of
the touch panel may have the aperture ratio deviation of 1% or
less, and has preferably the aperture ratio deviation of 0.5% or
less, but the aperture ratio deviation is not limited thereto.
[0043] A difference between surface resistances of region A and
region B of the first conductive pattern may be 20% or less, 10% or
less, and 5% or less. The surface resistance may be appropriately
adjusted through line breakage of the region having high density of
the conductive pattern among region A and region B.
[0044] Further, a difference between surface resistances of region
C and region D of the second conductive pattern may be 20% or less,
10% or less, and 5% or less. The surface resistance may be
appropriately adjusted through line breakage of the region having
high density of the conductive pattern among region C and region
D.
[0045] Further, in the present invention, since the patterns are
separated on different layers, it is confirmed that widths of
region AB and region CD can be defined. That is, since two
different patterns are spatially separated, even though lamination
is maximally precisely performed in the case where a printing
substrate is thick, in view of the boundary region, an additional
overlapping region is formed due to different spaces where the
patterns are present, which means that the degree of pattern
concealing property depends on a viewing direction (viewing angle).
In order to minimize this portion, in the present invention,
calculation is performed by applying the case where the regions
providing the aperture ratio gradient through the additional region
AB and region CD are different.
[0046] First, considering the case where the touch panel is
attached to reinforced glass through OCA (the same refractive index
as that of PET), in the case of the internal metal pattern, only
light having an angle of 73.3.degree. or more is observed from PET
to reinforced glass by a total reflection condition, and in this
case, the length of the region where overlapping occurs is obtained
by calculation of (OCA+PET) thickness.times.3.33. Therefore, in the
case where the thickness of PET is 125 .mu.m and the thickness of
OCA is 100 .mu.m, the aperture ratio gradient is provided to the
region ranging from the overlapping pattern as the center to both
sides of about 750 .mu.m.
[0047] In the case where the film is used as the touch panel as
another example, since a critical angle is 39.4.degree., the region
ranging from the overlapping pattern as the center to both sides of
about 185 .mu.m (225.times.0.8214) .mu.m is introduced as the
region for providing the aperture ratio gradient. This relationship
is a Relationship Equation under the assumption that the refractive
index of OCA is basically the same as that of PET, and there is a
difference in that in the case where OCA has the different
refractive index, the critical angle is defined at an interface
between PET and OCA according to the refractive index value of the
PET substrate and OCA. However, in the case where the critical
total reflection angle is defined, in the generalized Equation, the
relationship of thickness/tan .theta.c of the substrate is
maintained. FIG. 7 shows a mimetic view for the reason why the
aperture ratio gradient and the additional region are changed in
the case where reinforced glass is attached and in the case where
reinforced glass is not attached when OCA has the same refractive
index as the PET substrate.
[0048] Therefore, to sum it up, in the case where the touch panel
is manufactured through glass and OCA of 100 .mu.m on the substrate
having the thickness of 125 .mu.m, the size of region AB and region
CD that are the region for the additional aperture ratio gradient
is preferably 750 .mu.m or more, but is not limited thereto.
[0049] Further, in the present invention, when the patterns
provided on different layers are laminated in practice, a
recognition property of the pattern by the difference between the
aperture ratios is apprehended by designing the pattern having
various line widths and pitches in order to confirm the difference
between the aperture ratios, which is not visually recognized by
people. As a result, in the case where the aperture ratios are the
same while there is a difference between the line widths, the
difference between the immediately adjacent line widths is not
largely recognized within 1 .mu.m, but it is apprehended that in
the case where the line width is larger than 1 .mu.m, the
difference is easily recognized. When the mesh having the line
width of 3 .mu.m and the pitch of 300 .mu.m is set to a standard as
an example thereof, it is confirmed that in the mesh having the
line width of 2 .mu.m and 4 .mu.m and the pitch of 300, the line
widths are not largely differentiated based on 3 .mu.m, but the
difference is easily seen with regard to 5 .mu.m.
[0050] Therefore, through this, it can be confirmed that in the
present invention, it is more preferable that the line widths of
the patterns positioned on different surfaces be the same as each
other if possible. On the other hand, in the case where the
aperture ratios are different while the line widths are the same,
when the difference between the aperture ratios for each line width
is within 1%, it is difficult to recognize the difference, and when
the difference between the aperture ratios is 0.543 (based on
transmittance of 0.5%) or less, the difference is hardly
recognized. Therefore, it is confirmed that it is very important to
maintain the difference between the products of the aperture ratios
of each region at 1% or less and preferably 0.543% or less.
[0051] FIG. 9 shows the degree of recognition by the person
according to the difference between the aperture ratios with regard
to the line width of 2 .mu.m, 3 .mu.m, and 5 .mu.m. FIG. 9 shows a
region where the difference between the regions corresponding to
the difference in transmittance, which is represented by a color,
is hardly recognized visually, and in the case where the region
moves while maintaining the same difference according to the graph,
the same result is exhibited.
[0052] Therefore, to sum it up, since the present invention mainly
describes that uniformity of the aperture ratios is basically
ensured in view of the touch panel, in the case where the region is
divided like FIG. 8 (the case of the aperture ratio gradient region
may be divided, but for the convenience of understanding, the
region having a very large difference between the aperture ratios
is first divided), the case satisfying all of the following
Relationship Equations 1 to 3 is most preferable.
(Aperture ratio of region A.times.aperture ratio of region
C)-(Aperture ratio of region B.times.aperture ratio of region
D)<1 [Relationship Equation 1]
(Aperture ratio of region A.times.aperture ratio of region
C)-(Aperture ratio of region AB.times.aperture ratio of region
CD)<1 [Relationship Equation 2]
(Aperture ratio of region C.times.aperture ratio of region
D)-(Aperture ratio of region AB.times.aperture ratio of region
CD)<1 [Relationship Equation 3]
[0053] In Relationship Equations 1 to 3, the aperture ratio
represents a % value as a ratio of the opened region to the entire
region.
[0054] The first conductive pattern and the second conductive
pattern may comprise the pattern formed of a conductive metal line.
The pattern formed of the conductive metal line may comprise a
closed curve formed of a straight line, a curved line, or the
straight line and the curved line.
[0055] The first conductive pattern and the second conductive
pattern may be a regular pattern or an irregular pattern.
[0056] A pattern shape of the art, such as a mesh pattern, may be
used as the regular pattern. The mesh pattern may comprise a
regular polygonal pattern comprising one or more shapes of a
triangle, a quadrangle, a pentagon, a hexagon, and an octagon.
[0057] In the exemplary embodiment of the present invention, the
first conductive pattern and the second conductive pattern are a
regular pattern and comprise cross points formed by crossing a
plurality of predetermined lines among lines constituting the
conductive pattern, and in this case, the number of cross points
may be 3,000 to 122,500, 13,611 to 30,625, and 19,600 to 30,625 in
an area of 3.5 cm.times.3.5 cm. Further, according to the exemplary
embodiment of the present invention, when the pattern is provided
in a display, it is confirmed that an optical property of the
display is not largely spoiled in the case where the number of
cross points is 4,000 to 123,000.
[0058] Further, in the exemplary embodiment of the present
invention, the first conductive pattern and the second conductive
pattern are the irregular pattern and comprise cross points formed
by crossing a plurality of predetermined lines among the lines
constituting the conductive pattern, and in this case, the number
of cross points may be 6,000 to 245,000, 3,000 to 122,500, 13,611
to 30,625, and 19,600 to 30,625 in an area of 3.5 cm.times.3.5 cm.
Further, according to the exemplary embodiment of the present
invention, when the pattern is provided in the display, it is
confirmed that the optical property of the display is not largely
spoiled in the case where the number of cross points is 4,000 to
123,000.
[0059] The pitches of the first conductive pattern and the second
conductive pattern may be 600 .mu.m or less and 250 .mu.m or less,
but the pitch may be adjusted according to transmittance and
conductivity required by the person with ordinary skill in the
art.
[0060] The first conductive pattern and the second conductive
pattern used in the present invention are appropriately a material
having specific resistance of 1.times.10.sup.6 to 30.times.10.sup.6
ohmcm, and more preferably 7.times.10.sup.6 ohmcm or less.
[0061] In the present invention, the first conductive pattern and
the second conductive pattern may be the irregular pattern.
[0062] The irregular pattern comprises an edge structure of
continuously connected closed figures, the closed figures having
the same shape are not present in a predetermined irregular unit
area (1 cm.times.1 cm), and the number of vertexes of the closed
figures may be different from the number of vertexes of the
quadrangles having the same number as the closed figures. More
specifically, the number of vertexes of the closed figures may be
larger than or 1.9 to 2.1 times larger than the number of vertexes
of the quadrangles having the same number as the closed figures,
but is not limited thereto.
[0063] The closed figures are continuously connected to each other,
and for example, in the case where the closed figures are polygons,
the adjacent closed figures may have a shape sharing at least one
side.
[0064] The irregular pattern comprises the edge structure of
continuously connected closed figures, the closed figures having
the same shape are not present in a predetermined unit area (1
cm.times.1 cm) in the irregular pattern, and the number of vertexes
of the closed figures may be different from the number of vertexes
of the polygon formed by connecting shortest distances between
centers of gravity of the closed figures. More specifically, the
number of vertexes of the closed figures may be larger than or 1.9
to 2.1 times larger than the number of vertexes of the polygons
formed by connecting the shortest distances between centers of
gravity of the closed figures, but is not limited thereto.
[0065] The irregular pattern comprises the edge structure of the
continuously connected closed figures, the closed figures having
the same shape are not present in a predetermined unit area (1
cm.times.1 cm) in the irregular pattern, and a value of the
following Equation 1 may be 50 or more in the closed figures.
(Standard deviation of distances between the vertexes/Average of
the distances between the vertexes).times.100 [Equation 1]
[0066] The value of Equation 1 may be calculated in the unit area
of the conductive pattern. The unit area may be an area where the
conductive pattern is formed, and, for example, 3.5 cm.times.3.5 cm
and the like, but is not limited thereto.
[0067] In the present invention, the vertex means a point at which
the lines constituting the edge of the closed figures of the
conductive pattern cross each other.
[0068] The irregular pattern may have a shape of the edge structure
of the closed figures obtained by after disposing predetermined
points in regularly arranged unit cells, connecting the points to
the closest points thereto as compared to the distances from other
points.
[0069] In this case, in the case where randomness is introduced
into a manner where predetermined points are disposed in the
regularly arranged unit cells, the irregular pattern may be formed.
For example, in the case where randomness is provided as 0, if the
unit cell is a square, the conductive pattern has a square mesh
structure, and if the unit cell is a regular hexagon, the
conductive pattern has a honeycomb structure. That is, the
irregular pattern means a pattern where randomness is not 0.
[0070] A leaning phenomenon and the like of lines constituting the
pattern may be suppressed, uniform transmittance may be obtained
from the display, the linear density to the unit area may be
maintained as the same value, and uniform conductivity may be
ensured by the conductive pattern having the irregular pattern
shape according to the present invention.
[0071] In the present invention, the materials of the first
conductive pattern and the second conductive pattern are not
particularly limited, but are preferably metal. It is preferable
that the materials of the first conductive pattern and the second
conductive pattern have excellent conductivity and be easily
etched.
[0072] In the present invention, even though the material having
the total reflectance of 70 to 80% or more is used, it is possible
to decrease the total reflectance, decrease visibility of the
electric conductive pattern, and maintain or improve a contrast
property.
[0073] Specific examples of the materials of the first conductive
pattern and the second conductive pattern preferably comprise a
single film or a multilayered film comprising gold, silver,
aluminum, copper, neodymium, molybdenum, nickel, or an alloy
thereof. Herein, the thickness of a first conductive pattern and a
second conductive pattern is not particularly limited, but is
preferably 0.01 to 10 .mu.m in terms of conductivity of the
conductive pattern and economic efficiency of the forming process
thereof.
[0074] The forming of the first conductive pattern and the second
conductive pattern may adopt a method using an etching resist
pattern. The etching resist pattern may be formed by using a
printing method, a photolithography method, a photography method, a
method using a mask, or laser transferring, for example, thermal
transfer imaging, and the printing method or photolithography
method is more preferable. The electric conductive pattern may be
etched by using the etching resist pattern, and the etching resist
pattern may be removed.
[0075] In the present invention, the line widths of the first
conductive pattern and the second conductive pattern may be 10
.mu.m or less, 7 .mu.m or less, 5 .mu.m or less, 4 .mu.m or less, 2
.mu.m or less, or 0.1 .mu.m or more. To be more specific, the line
widths of the first conductive pattern and the second conductive
pattern may be 0.1 to 1 .mu.m, 1 to 2 .mu.m, 2 to 4 .mu.m, 4 to 5
.mu.m, 5 to 7 .mu.m, or the like, but are not limited thereto.
[0076] Further, the line widths of the first conductive pattern and
the second conductive pattern may be 10 .mu.m or less and the
thicknesses thereof may be 10 .mu.m or less, the line widths of the
first conductive pattern and the second conductive pattern may be 7
.mu.m or less and the thicknesses thereof may be 1 .mu.m or less,
or the line widths of the first conductive pattern and the second
conductive pattern may be 5 .mu.m or less and the thicknesses
thereof may be 0.5 .mu.m or less.
[0077] To be more specific, in the present invention, the line
widths of the first conductive pattern and the second conductive
pattern may be 10 .mu.m or less, and in the first conductive
pattern and the second conductive pattern, the number of vertexes
of the closed figures in the area of 3.5 cm.times.3.5 cm may be
6,000 to 245,000. Further, the line widths of the first conductive
pattern and the second conductive pattern may be 7 .mu.m or less,
and in the first conductive pattern and the second conductive
pattern, the number of vertexes of the closed figures in the area
of 3.5 cm.times.3.5 cm may be 7,000 to 62,000. Further, the line
widths of the first conductive pattern and the second conductive
pattern may be 5 .mu.m or less, and in the first conductive pattern
and the second conductive pattern, the number of vertexes of the
closed figures in the area of 3.5 cm.times.3.5 cm may be 15,000 to
62,000.
[0078] The aperture ratio of the first conductive pattern and the
second conductive pattern, that is, the ratio of the area not
covered by the pattern, may be 70% or more, 85% or more, and 95% or
more. In addition, the aperture ratios of the first conductive
pattern and the second conductive pattern may be 90 to 99.9%, but
are not limited thereto.
[0079] The first conductive pattern and the second conductive
pattern used in the present invention are appropriately a material
having specific resistance of 1.times.10.sup.6 to 30.times.10.sup.6
ohmcm, and more preferably 7.times.10.sup.6 ohmcm or less.
[0080] The first conductive pattern and the second conductive
pattern may comprise the mesh pattern, and region A and region D
may have different mesh rotational angles.
[0081] In the present invention, the transparent substrate is not
particularly limited, but it is preferable to use the substrate
where the light transmittance is 50% or more, and preferably 75% or
more. Specifically, glass may be used as the transparent substrate,
and the plastic substrate or the plastic film may be used. A
material known in the art may be used as the plastic substrate or
film, and for example, a material formed of one or more resins
selected from polyacryls, polyurethanes, polyesters, polyepoxys,
polyolefines, polycarbonates, and celluloses may be used. To be
more specific, it is preferable to use the film having the visible
ray transmittance of 80% or more, such as PET (polyethylene
terephthalate), PVB (polyvinylbutyral), PEN (polyethylene
naphthalate), PES (polyethersulfone), PC (polycarbonate), and
acetyl celluloid. The thickness of the plastic film is preferably
12.5 to 500 .mu.m, more preferably 50 to 450 .mu.m, and even more
preferably 50 to 250 .mu.m. The plastic substrate may be a
substrate having a structure in which various functional layers
such as a gas barrier layer for blocking moisture and gas on one
surface or both surfaces of the plastic film, a hard coat layer for
compensating strength, and a low reflection layer for improving
reflectance are laminated. The functional layer that can be
comprised in the plastic substrate is not limited thereto, and
various functional layers may be provided.
[0082] In the present invention, it is preferable to use the metal
having excellent electric conductivity as the material of the
conductive pattern. In addition, the specific resistance value of
the conductive pattern material is preferably 1 microOhm cm or more
and 100 microOhm cm or less. Copper, silver, gold, iron, nickel,
aluminum, titanium, oxides and nitrides thereof, and the like may
be used while being mixed as specific examples of the conductive
pattern material, and it is preferable to use aluminum, and oxides
and nitrides thereof together in terms of cost.
[0083] Particularly, in the present invention, metal having
excellent electric conductivity may be used as the conductive
pattern material to implement excellent sensitivity of the touch
panel, low power driving caused by a rapid response speed, and
flexible touch due to high softness of metal.
[0084] In the present invention, in order to form a desired pattern
on each layer, it is possible to form the precise electric
conductive pattern having the small line width on the transparent
substrate by using a printing method, a photolithography method, a
photography method, a method using a mask and the like. The
printing method may be performed by using a method in which the
paste or ink comprising the electric conductive pattern material is
transferred on the transparent substrate in the desired pattern
form and then sintered. The printing method is not particularly
limited, and a printing method such as offset printing, screen
printing, gravure printing, flexo printing, inkjet printing, and
nano imprint may be used, and one or more complex methods among the
methods may be used. The printing method may adopt a roll to roll
method, roll to plate, plate to roll, or plate to plate method.
[0085] In the present invention, it is preferable to apply a
reverse offset printing method in order to implement the precise
electric conductive pattern. To this end, in the present invention,
a method where ink that can be used as a resist during etching is
applied on an entire surface of a silicon-based rubber called a
blanket, an unnecessary portion is removed through an intaglio on
which a pattern called a first cliche is formed, a printing pattern
remaining on the blanket is secondly transferred on a film or a
substrate such as glass on which metal and the like are deposited,
and a desired pattern is formed through sintering and etching
processes may be performed. In the case where this method is used,
there is a merit in that resistance in a thickness direction can be
uniformly maintained because uniformity of line heights is ensured
over the entire region by using the substrate on which metal is
deposited. In addition to this, the present invention may comprise
a direct printing method where conductive ink such as Ag ink is
directly printed by using the aforementioned reverse offset
printing method and then sintered to form a desired pattern. In
this case, the line heights of the pattern may be made uniform by
printing pressure, and conductivity may be provided by a heat
sintering process for the purpose of connecting Ag nanoparticles
due to inter-surface fusion, a microwave sintering process/a laser
partial sintering process, or the like.
[0086] In the present invention, it is not limited to the
aforementioned printing method, and the photolithography process
may be used. For example, the photolithography process may be
performed by using the method in which the electric conductive
pattern material layer is formed on the entire surface of the
transparent substrate, the photoresist layer is formed thereon, the
photoresist layer is patterned by the selective exposure and
developing processes, the electric conductive pattern is patterned
by using the patterned photoresist layer as the etching resist, and
the photoresist layer is removed.
[0087] The present invention may adopt the photolithography method.
For example, after the picture photosensitive material comprising
silver halide is applied on the transparent substrate, the pattern
may be formed by selective exposing and developing processes of the
photosensitive material. A detailed example will be described
below. First, the photosensitive material for negative is applied
on the substrate on which the pattern will be formed. In this case,
a polymer film such as PET and acetyl celluloide may be used as the
substrate. The polymer film material on which the photosensitive
material is applied is called the film herein. The photosensitive
material for negative may be formed of silver halide in which AgBr
that is very sensitive to light and regularly reacted therewith and
a small amount of AgI were mixed with each other. Since the image
developed by picturing the general photosensitive material for
negative is a negative picture that is opposite to the subject in
terms of light and shade, the picturing may be performed by using
the mask having the pattern form that will be formed and preferably
an irregular pattern form.
[0088] Plating treatment may be further performed in order to
increase conductivity of the conductive pattern formed by using the
photolithography and photography processes. The plating may adopt
an electroless plating method, copper or nickel may be used as the
plating material, and after copper plating is performed, nickel
plating may be performed thereon, but the scope of the present
invention is not limited thereto.
[0089] The present invention may adopt the method using the mask.
For example, patterning may be performed by depositing the
conductive pattern material on the substrate after the mask having
the desired conductive pattern form is disposed to be close to the
substrate.
[0090] In this case, the depositing method may adopt a heat
deposition method by heat or electron beam, a PVD (physical vapor
deposition) method such as sputter, and a CVD (chemical vapor
deposition) method using an organometal material.
[0091] As described above, a touch panel according to the present
invention can improve transmittance, a concealing property,
uniformity, and the like of a conductive pattern by providing the
conductive patterns comprising regions having different aperture
ratios on both surfaces of a transparent substrate at predetermined
positions, or laminating the transparent substrate having the
conductive patterns comprising the regions having different
aperture ratios.
* * * * *