U.S. patent application number 13/347859 was filed with the patent office on 2012-10-18 for touch sensor with a conductive line having different widths.
Invention is credited to David Brent Guard, Tsung-Ching Wu, Esat Yilmaz.
Application Number | 20120262412 13/347859 |
Document ID | / |
Family ID | 47005588 |
Filed Date | 2012-10-18 |
United States Patent
Application |
20120262412 |
Kind Code |
A1 |
Guard; David Brent ; et
al. |
October 18, 2012 |
Touch Sensor with a Conductive Line Having Different Widths
Abstract
In one embodiment, a touch sensor includes one or more meshes of
conductive material. Each of the meshes includes a plurality of
conductive lines. A first one of the conductive lines has a first
portion and a second portion. The first portion is wider than the
second portion.
Inventors: |
Guard; David Brent;
(Southampton, GB) ; Yilmaz; Esat; (Santa Cruz,
CA) ; Wu; Tsung-Ching; (Saratoga, CA) |
Family ID: |
47005588 |
Appl. No.: |
13/347859 |
Filed: |
January 11, 2012 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
|
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13089061 |
Apr 18, 2011 |
|
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13347859 |
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Current U.S.
Class: |
345/174 ;
200/512 |
Current CPC
Class: |
Y10T 29/49155 20150115;
G06F 3/0446 20190501; G06F 2203/04112 20130101; G06F 3/0445
20190501; G06F 2203/04103 20130101 |
Class at
Publication: |
345/174 ;
200/512 |
International
Class: |
G06F 3/044 20060101
G06F003/044; H01H 1/10 20060101 H01H001/10 |
Claims
1. An apparatus comprising: a touch sensor comprising a first mesh
of conductive material and a second mesh of conductive material,
each of the meshes comprising a plurality of conductive lines, a
first one of the conductive lines having a first portion and a
second portion, the first portion being wider than the second
portion, the first one of the conductive lines being coupled to a
second one of the conductive lines, the second one of the
conductive lines having a third portion and a fourth portion, the
third portion being wider than the fourth portion; and one or more
computer-readable non-transitory storage media coupled to the touch
sensor and embodying logic that is configured when executed to
control the touch sensor.
2. The apparatus of claim 1, wherein each of one or more of the
conductive lines is a substantially straight line.
3. The apparatus of claim 1, wherein each of one or more of the
conductive lines is substantially curved.
4. The apparatus of claim 1, wherein each of one or more of the
conductive lines is substantially sinusoidal.
5. An apparatus comprising: a touch sensor comprising one or more
meshes of conductive material, each of the meshes comprising a
plurality of conductive lines, a first one of the conductive lines
having a first portion and a second portion, the first portion
being wider than the second portion; and one or more
computer-readable non-transitory storage media coupled to the touch
sensor and embodying logic that is configured when executed to
control the touch sensor.
6. The apparatus of claim 5, wherein the one or more meshes of
conductive material comprise a first mesh and a second mesh, the
first mesh being disposed on a first surface of a substrate and the
second mesh being disposed on a second surface of the substrate
opposite the first surface.
7. The apparatus of claim 5, wherein the one or more meshes of
conductive material comprise a first mesh and a second mesh, the
first mesh being disposed on a surface of a first substrate and the
second mesh being disposed on a surface of a second substrate.
8. The apparatus of claim 5, wherein each of one or more of the
conductive lines is a substantially straight line.
9. The apparatus of claim 5, wherein each of one or more of the
conductive lines is substantially curved.
10. The apparatus of claim 5, wherein each of one or more of the
conductive lines is substantially sinusoidal.
11. The apparatus of claim 5, wherein the first one of the
conductive lines is coupled to a second one of the conductive
lines, the second one of the conductive lines having a third
portion and a fourth portion, the third portion being wider than
the fourth portion.
12. The apparatus of claim 5, wherein the first one of the
conductive lines has a third portion connected to the first portion
and the second portion, wherein a width of the third portion tapers
from the width of the first portion to the width of the second
portion.
13. A touch sensor comprising: one or more meshes of conductive
material; and each of the meshes comprising a plurality of
conductive lines, a first one of the conductive lines having a
first portion and a second portion, the first portion being wider
than the second portion.
14. The touch sensor of claim 13, wherein the one or more meshes of
conductive material comprise a first mesh and a second mesh, the
first mesh being disposed on a first surface of a substrate and the
second mesh being disposed on a second surface of the substrate
opposite the first surface.
15. The touch sensor of claim 13, wherein the one or more meshes of
conductive material comprise a first mesh and a second mesh, the
first mesh being disposed on a surface of a first substrate and the
second mesh being disposed on a surface of a second substrate.
16. The touch sensor of claim 13, wherein each of one or more of
the conductive lines is a substantially straight line.
17. The touch sensor of claim 13, wherein each of one or more of
the conductive lines is substantially curved.
18. The touch sensor of claim 13, wherein each of one or more of
the conductive lines is substantially sinusoidal.
19. The touch sensor of claim 13, wherein the first one of the
conductive lines is coupled to a second one of the conductive
lines, the second one of the conductive lines having a third
portion and a fourth portion, the third portion being wider than
the fourth portion.
20. The touch sensor of claim 13, wherein the first one of the
conductive lines has a third portion connected to the first portion
and the second portion, wherein a width of the third portion tapers
from the width of the first portion to the width of the second
portion.
Description
RELATED APPLICATION
[0001] This application is a continuation under 35 U.S.C. .sctn.120
of U.S. patent application Ser. No. 13/089,061, filed 18 Apr.
2011.
TECHNICAL FIELD
[0002] This disclosure generally relates to touch sensors.
BACKGROUND
[0003] A position sensor can detect the presence and location of a
touch by a finger or by an object, such as a stylus, within an area
of an external interface of the position sensor. In a touch
sensitive display application, the position sensor enables, in some
circumstances, direct interaction with information displayed on the
screen, rather than indirectly via a mouse or touchpad. Position
sensors can be attached to or provided as part of devices with a
display. Examples of devices with displays include, but are not
limited to, computers, personal digital assistants, satellite
navigation devices, mobile telephones, portable media players,
portable game consoles, public information kiosks, and point of
sale systems. Position sensors have also been used as control
panels on various appliances.
[0004] There are a number of different types of position sensors.
Examples include, but are not limited to resistive touch screens,
surface acoustic wave touch screens, capacitive touch screens, and
the like. A capacitive touch screen, for example, may include an
insulator coated with a transparent conductor in a particular
pattern. When an object, such as a finger or a stylus, touches the
surface of the screen there may be a change in capacitance. This
change in capacitance may be sent to a controller for processing to
determine where the touch occurred on the touch screen.
[0005] In a mutual capacitance configuration, for example, an array
of conductive drive electrodes or lines and conductive sense
electrodes or lines can be used to form a touch screen having
capacitive nodes. A node may be formed where a drive electrode and
a sense electrode overlap. The electrodes may be separated by an
insulator to avoid electrical contact. The sense electrodes may be
capacitively coupled with the drive electrodes at the nodes. A
pulsed or alternating voltage applied on a drive electrode may
therefore induce a charge on the sense electrodes that overlap with
the drive electrode. The amount of induced charge may be
susceptible to external influence, such as from the proximity of a
nearby finger. When an object touches the surface of the screen,
the capacitance change at each node on the grid can be measured to
determine the position of the touch.
[0006] While clear conductors such as ITO may be used for
electrodes, opaque metal electrodes also may be used. The opaque
metal electrodes may be made of a conductive mesh of thin
conductors, which may be of copper, silver or other conductive
materials. The thin conductors may be made very thin as to be
substantially invisible to the naked eye.
SUMMARY
[0007] An electrode pattern for a position sensing panel may have
an array of mesh cells formed by sinusoidaly shaped conductive
lines extending between vertices of the mesh cells.
BRIEF DESCRIPTION OF THE FIGURES
[0008] The figures depict one or more implementations in accordance
with the present disclosure, by way of example, not by way of
limitation. In the figures, like reference numerals refer to the
same or similar elements.
[0009] FIG. 1 is a cross-sectional view of an exemplary touch
sensitive panel and a display;
[0010] FIGS. 2a-b illustrate schematically exemplary electrode
patterns useable in the touch sensitive panel of FIG. 1;
[0011] FIGS. 3A-3C illustrate schematically an arrangement of two
of the electrode patterns of FIG. 2a overlying one another;
[0012] FIG. 4 illustrates schematically another electrode pattern
useable in the touch sensitive panel of FIG. 1;
[0013] FIG. 5 illustrates schematically another electrode pattern
useable in the touch sensitive panel of FIG. 1;
[0014] FIG. 6 illustrates schematically another electrode pattern
useable in the touch sensitive panel of FIG. 1;
[0015] FIG. 7 illustrates schematically another electrode pattern
useable in the touch sensitive panel of FIG. 1;
[0016] FIG. 8 illustrates schematically another electrode pattern
useable in the touch sensitive panel of FIG. 1;
[0017] FIG. 9 illustrates schematically another electrode pattern
useable in the touch sensitive panel of FIG. 1;
[0018] FIG. 10 illustrates schematically another electrode pattern
useable in the touch sensitive panel of FIG. 1;
[0019] FIG. 11 illustrates schematically another electrode pattern
useable in the touch sensitive panel of FIG. 1;
[0020] FIG. 12 illustrates schematically another electrode pattern
useable in the touch sensitive panel of FIG. 1;
[0021] FIG. 13 illustrates schematically another electrode pattern
useable in the touch sensitive panel of FIG. 1; and
[0022] FIG. 14 illustrates schematically another electrode pattern
useable in the touch sensitive panel of FIG. 1.
DETAILED DESCRIPTION
[0023] In the following detailed description, numerous specific
details are set forth by way of examples. In order to avoid
unnecessarily obscuring examples of the present disclosure, those
methods, procedures, components, and/or circuitry that are
well-known to one of ordinary skill in the art have been described
at a relatively high level.
[0024] Reference is now made in detail to the examples illustrated
in the accompanying figures and discussed below.
[0025] A display may be overlaid with a touch position-sensing
panel to implement a touch sensitive display device. Exemplary
displays include liquid crystal displays, active matrix liquid
crystal displays, electroluminescent displays, electrophoretic
displays, plasma displays, cathode-ray displays, OLED displays, or
the like. It will be appreciated that light emitted from the
display may be able to pass through the touch position-sensing
panel with minimal absorption or obstruction.
[0026] FIG. 1 illustrates an exemplary touch position-sensing panel
1 which overlies a display 2. In the illustrated example, the panel
1 includes an insulating substrate 3 having two opposing faces.
Although touch sensors may implement other types of touch sensing,
for discussion purposes, the drawing shows an example of a
structure that may be used to implement a mutual capacitance type
touch sensitive panel.
[0027] The panel 1 includes a number of electrodes 4(X) and a
number of electrodes 5(Y) provided on opposite faces 3a and 3b of
the substrate 3. The electrodes 4(X), which may be on face 3b, may
be arranged in one direction and the electrodes 5(Y), which may be
on face 3a, may be arranged in a direction different than the
direction of electrodes 4(X). Other conductive tracks may also be
provided on the opposing faces 3a and 3b of the substrate 3. Such
other conductive tracks may provide drive and sense connections to
the electrodes 4(X) and 5(Y). The substrate 3 may be provided
adjacent to the display 2 such that electrodes 4(X) are arranged
between the display 2 and the substrate 3. An adhesive layer 6 of
an optically clear adhesive may be between the electrodes 4(X) and
a transparent covering sheet 7. Another adhesive layer 8 of an
optically clear adhesive may be between the electrodes 5(Y) and a
transparent covering sheet 9. A gap may be formed between the
display 2 and the transparent covering sheet 7.
[0028] The transparent covering sheet 7 and the adhesive layer 6 of
optically clear adhesive may encapsulate the electrodes 4(X), and
any other conductive tracks formed on face 3b of the substrate 3.
The transparent covering sheet 9 and the adhesive layer 8 of
optically clear adhesive may encapsulate the electrodes 5(Y), and
any other conductive tracks formed on face 3a of the substrate 3.
The encapsulation of the electrodes 4(X) and 5(Y), and any other
conductive tracks, may provide protection from physical and
environmental damage. In some examples, portions of the conductive
tracks may be exposed to provide connection points for connection
to external drive circuitry.
[0029] In the mutual capacitance example, electrodes 4(X) may be
drive electrodes provided on face 3b of the substrate 3, and
electrodes 5(Y) may be sense electrodes provided on the opposing
face 3a of the substrate 3. Capacitive sensing channels may be
formed by capacitive coupling nodes in the localized regions at an
around where electrodes 4(X) and 5(Y) cross over each other and are
separated by the substrate 3.
[0030] One or both of the sets of electrodes 4(X) and 5(Y) may be
formed from a conductive material, such as a metal. Suitable metals
include copper, silver, gold, aluminum, tin and other metals used
in conductive wiring. In some examples, the sense electrodes may be
patterned in narrow lines to allow most of the light emitted from
the display and incident on the sense electrode layer to pass
through the electrode layer between the narrow metal lines. The
narrow lines may be no more than 20 microns wide. An exemplary
range may be 1-5 microns. Narrower lines have reduced visibility to
the naked eye. By forming electrodes 4(X) or 5(Y) from narrow
conductive lines, the position-sensing panel may be formed such
that no more than about 10% of the active area is covered by the
metal lines of the electrodes. Less coverage of the active area
allows for greater transparency of the position-sensing panel
reduces visibility of the electrodes to the human eye and reduces
perceptible darkening or other loss of display quality. An
exemplary coverage may be less than 5%.
[0031] In some examples, the electrodes 4(X) may be formed from a
clear conductive material and the electrodes 5(Y) may be formed
from narrow conductive lines. In other examples, the electrodes
4(X) may be formed from narrow conductive lines and the electrodes
5(Y) may be formed from a clear conductive material.
[0032] In an example where other conductive tracks in addition to
the electrodes 4(X) and 5(Y) are provided on the substrate 3, the
other conductive tracks may also be formed from a clear conductive
material or narrow conductive lines, in a manner similar to the
electrode layers 4(X) and 5(Y). In an example where the other
conductive tracks, or parts of the other conductive tracks, lie
outside a visible region of the display 2, the
light-transmissibility of the other conductive tracks is of no
concern.
[0033] FIG. 2a illustrates an exemplary electrode pattern 10 which
may be used in the touch position-sensing panel 1. The exemplary
electrode pattern may be used to form any one electrode of either
set of the electrodes 4(X) and 5(Y). The electrode pattern 10 may
be formed by a number of straight conductive lines 11 arranged to
interconnect at connection points to define a conductive grid or
mesh pattern made up of an array of square shaped mesh cells 13
arranged in a layer. The connection points of the conductive lines
11 are the vertices 12 of the square shaped mesh cells 13. The
conductive lines may be formed of copper with a width in the range
approximately 1 .mu.m to approximately 10 .mu.m and size of the
mesh pattern, that is, the spacing of the vertices, may be in the
range approximately 500 .mu.m to approximately 10 mm. In one
example, the electrode pattern 10 may be arranged so that no more
than approximately 5% of the surface of the touch position-sensing
panel is covered by the conductive lines 11. Thus, the contribution
of the conductive lines to the attenuation of light through a
sensor should not be more than approximately 5%. Accordingly,
although the conductive lines 11 may be opaque, in this example,
the combined optical transmissivity of the electrode pattern 10 and
all other electrode patterns on the panel may be 90% or more,
allowing any display below the touch position-sensing panel 1 to be
visible with little perceptible darkening or other loss of display
quality.
[0034] In other examples, the electrode pattern may be formed by a
number of square shaped mesh cells 13a that do not have four metal
lines meet at vertices. Instead of the connection points of the
conductive lines being the vertices of the square shaped mesh cells
as shown in FIG. 2a, in FIG. 2b, each of the square shaped mesh
cells 13a may be separated from adjacent cells by a connecting
segment 14. This arrangement may result in reduced line density on
the vertices 12 by reducing the number of converging metal lines
11a from 4 to 3. While the connecting segments 14 in FIG. 2b are
straight, in other examples, the connecting segments may be
sinusoidal or non-linear, and may be at any angle relative to the
vertices 12a.
[0035] FIGS. 3A-3C illustrate an example of electrode patterns 10a
and 10b formed so that the two electrode patterns 10a and 10b
overlay one another. The two electrode patterns 10a and 10b may be
offset so that the vertices 12a, 12b of each one of the electrode
patterns 10a and 10b are located at, or near to, the centers of the
square shapes 13a, 13b of the other one of the electrode patterns
10a and 10b. As a result of this offsetting of the two electrode
patterns 10a and 10b, the conductive lines 11a and 11b of the two
electrode patterns 10a and 10b may be distributed evenly across the
touch position-sensing panel 1.
[0036] In other examples, the mesh pattern may be made up of an
array of other regular trapezoid shaped mesh cells. In one example,
the mesh pattern may be made up of an array of two different
diamond shaped mesh cells which tessellate to form the mesh
pattern.
[0037] An example of a portion of an electrode pattern 14 is shown
in FIG. 4. In this illustrated example, the electrode pattern 14
may be formed of conductive lines 15 arranged to interconnect at
connection points to define a conductive grid or mesh pattern made
up of an array of substantially square shaped mesh cells 17
arranged in a layer. The connection points of the conductive lines
15 form vertices 16 of the square shaped mesh cells 17. In FIG. 4,
a single substantially square shaped mesh cell 17 is shown together
with parts of the conductive lines 15 defining adjacent
substantially square shaped mesh cells 17.
[0038] In the illustrated example of FIG. 4, the conductive lines
15 extending between the vertices 16 are not straight. As can be
seen in the illustrated example, each of the conductive lines 15
may have a sinusoidal shape. Each conductive metal line 15 may be
arranged as a sinusoidal line centered on a path that would be
taken by a straight line between the vertices 16 linked by the
conductive metal line 15. Thus, comparing the examples illustrated
in FIG. 2 and FIG. 4, each sinusoidal conductive metal line 15
illustrated in FIG. 4 may be centered about, and may extend to
either side of, one of the straight conductive lines 11 illustrated
in FIG. 2, shown as dotted lines in FIG. 4. The mesh cells 17 shown
in FIG. 4 may be described as substantially square because,
although the vertices 16 are arranged in a square, the sinusoidal
shape of the conductive lines 15 may result in mesh cells 17 that
are substantially, but not precisely, square shaped.
[0039] The sinusoidal shape of the conductive lines 15 as shown in
FIG. 4 may reduce diffraction effects which may be encountered if
straight conductive lines are used. Such diffraction effects may
result in the appearance of "starburst" patterns when a touch
position-sensing panel is subject to bright ambient light. Such
diffraction effects may result in color shifting, changing the
apparent colors of liquid crystal display (LCD) elements of a
display visible through a touch position-sensing panel, and may
obscure the image being displayed.
[0040] The sinusoidal shape of the conductive lines 15 in the
illustrated example may reduce the visibility of reflections from
the conductive lines when a touch position sensing panel is
illuminated by light from a point illumination source, such as the
sun on a clear day. The sinusoidal shape of the conductive lines 15
may tend to distribute or disperse the apparent position on the
touch position sensing panel of such reflections, and so may
minimize the perceived visibility of repetitive reflection
patterns. Such repetitive reflection patterns are readily perceived
by the human eye.
[0041] In FIG. 4, each sinusoidal conductive metal line makes two
complete sinusoidal cycles between two vertices 16. In other
examples, each sinusoidal conductive line may make a different
number of cycles between two vertices 16.
[0042] In some examples, the sinusoidal conductive lines may be
formed as continuous curves. In other examples, the sinusoidal
conductive lines may be formed by a number of short straight line
sections arranged in a triangular waveform shape to approximate a
sinusoidal shape. In other examples, the conductive lines may be
shaped as other types of curves. In some examples, the conductive
lines may be shaped as curves extending from a path that would be
taken by a straight line between the vertices linked by the
conductive metal line.
[0043] Another example of an electrode pattern 18 is shown in FIG.
5. In this example, the electrode pattern 18 may be formed by
conductive lines 20 arranged to interconnect at connection points
to define a conductive grid or mesh pattern made up of an array of
substantially diamond shaped mesh cells 19 arranged in a layer. The
connection points of the conductive lines 20 form vertices 21 of
the diamond shaped mesh cells 19. In FIG. 5 a single substantially
diamond shaped mesh cell 19 is shown, together with parts of the
conductive lines 20 defining adjacent ones of the substantially
diamond shaped mesh cells 19. The mesh cells 19 in FIG. 5 may be
substantially diamond shaped. For example, although the vertices 21
are arranged in a diamond, the sinusoidal shape of the conductive
lines 20 may result in mesh cells 19 that are substantially diamond
shaped, varying from a straight line, as shown by the dotted
lines.
[0044] In other examples, the mesh pattern may be made up of an
array of other substantially regular trapezoid shaped mesh cells.
In one example, the mesh pattern may be made up of a tessellated
array of two different substantially diamond shaped mesh cells.
[0045] In other examples, the amplitude of the sinusoidal shape of
the sinusoidal conductive lines may be varied. For example, the
distance the peaks of the sinusoidal shaped conductive lines extend
away from a path that would be taken by a straight line between the
vertices linked by the sinusoidal conductive lines may be varied.
The amplitude of the sinusoidal shape of the sinusoidal conductive
lines may be varied between the different sinusoidal conductive
lines, and may also be varied at different points along one, some
or all of the sinusoidal conductive lines.
[0046] A portion of another electrode pattern 22 is shown in FIG.
6. In this example, the electrode pattern 22 may be formed by
conductive lines 23 arranged to interconnect at connection points
to define a conductive grid or mesh pattern made up of an array of
substantially square shaped mesh cells 24 arranged in a layer. The
connection points of the conductive lines 23 form vertices 25 of
the corners of the mesh cell 24. In FIG. 6, a single mesh cell 24
is shown, together with parts of the conductive lines 23 defining
adjacent mesh cells 24. Although the vertices 25 may be arranged at
the corners of the mesh cell to form a square shape, the sinusoidal
shape of the conductive lines 23 may vary from a straight line and
results in mesh cells 24 that may be substantially square.
[0047] For example, as shown in FIG. 6, the conductive lines 23
extending between the vertices 25 may have a sinusoidal shape
similar to the example illustrated in FIG. 4. Each conductive metal
line 23 may be arranged as a sinusoidal line centered on a path
that would be taken by a straight line between the vertices 25
linked by the sinusoidal conductive metal line 23.
[0048] In FIG. 6, the sinusoidal conductive lines 23 may have
varying amplitudes. For example, sinusoidal conductive metal line
23a and sinusoidal conductive metal line 23b may have different
amplitudes. The conductive metal line 23a may have a smaller
amplitude than the sinusoidal conductive metal line 23b. Further, a
sinusoidal conductive metal line 23c may have sections 23d and 23e
with different amplitudes. The section 23d of the sinusoidal
conductive metal line 23c may have a larger amplitude than the
sections 23e of the sinusoidal conductive metal line 23c.
[0049] As shown, the sinusoidal conductive lines in FIG. 6 may have
two different amplitudes. In other examples, the sinusoidal
conductive lines may have other number of different amplitudes.
[0050] In an example of an electrode using the cell of FIG. 6, the
mesh pattern may be made up of an array of substantially square
shaped mesh cells, such as an array of other substantially regular
trapezoid shaped mesh cells. In another example, the mesh pattern
may be made up of an array of substantially diamond shaped mesh
cells. In one example, the mesh pattern may be made up of a
tessellated array of two different substantially diamond shaped
mesh cells.
[0051] In other examples, the wavelength of the sinusoidal shape of
the sinusoidal conductive lines may be varied. That is, the
distance between the crossing points where the sinusoidal shaped
conductive lines cross a path that would be taken by a straight
line between the vertices linked by the sinusoidal conductive lines
may be varied. The wavelength of the sinusoidal shape of the
sinusoidal conductive lines may be varied between the different
sinusoidal conductive lines and/or may be varied at different
points along one, some or all of the sinusoidal conductive
lines.
[0052] A portion of another electrode pattern 26 is shown in FIG.
7. In this example, the electrode pattern 26 may be formed by
conductive lines 27 arranged to interconnect at connection points
to define a conductive grid or mesh pattern made up of an array of
substantially square shaped mesh cells 28 arranged in a layer,
similar to the electrode pattern 14 illustrated in FIG. 4. The
connection points of the conductive lines 27 form vertices 29 of
the square shaped mesh cells 28. In FIG. 7, a single substantially
square shaped mesh cell 28 is shown, together with parts of the
conductive lines 27 defining adjacent substantially square shaped
mesh cells 28.
[0053] As shown in FIG. 7, the conductive lines 27 extending
between the vertices 29 may have a sinusoidal shape. Each
conductive metal line 27 may be arranged as a sinusoidal line
centered on a path that would be taken by a straight line between
the vertices 29 linked by the sinusoidal conductive metal line
27.
[0054] In this example, the sinusoidal conductive lines 27 may have
varying wavelengths. As is illustrated in FIG. 7, a sinusoidal
conductive metal line 27a, a sinusoidal conductive metal line 27b,
and a sinusoidal conductive metal line 27c may each have different
wavelengths. The conductive metal line 27a may have a smaller
wavelength than the sinusoidal conductive metal line 27b. In turn,
the sinusoidal conductive metal line 27b may have a smaller
wavelength than the sinusoidal conductive metal line 27c. Further,
a sinusoidal conductive metal line 27d may have sections 27e and
27f with different wavelengths. The section 27e of the sinusoidal
conductive metal line 27d may have a shorter wavelength than the
sections 27f of the sinusoidal conductive metal line 27d.
[0055] As shown, the sinusoidal conductive lines of FIG. 7 may have
three different wavelengths. In other examples, the sinusoidal
conductive lines may have any number of different wavelengths.
[0056] In other examples, both the amplitude and the wavelength of
the sinusoidal shape of the sinusoidal conductive lines may be
varied. The amplitude and/or the wavelength of the sinusoidal shape
of the sinusoidal conductive lines may be varied between the
different sinusoidal conductive lines, and may also be varied at
different points along one, some or all of the sinusoidal
conductive lines.
[0057] A portion of another electrode pattern 30 is shown in FIG.
8. In this example, the electrode pattern 30 may be formed by
conductive lines 31 arranged to interconnect at connection points
to define a conductive grid or mesh pattern made up of an array of
substantially square shaped mesh cells 32 arranged in a layer. The
connection points of the conductive lines 31 form vertices 33 of
the square shaped mesh cells 32. In FIG. 8, a single substantially
square shaped mesh cell 32 is shown, together with parts of the
conductive lines 31 defining adjacent substantially square shaped
mesh cells 32. The mesh cells 32 in the example shown in FIG. 8 may
be substantially square.
[0058] In the example of FIG. 8, the conductive lines 31 extending
between the vertices 33 have a varying sinusoidal shape. Each
conductive metal line 31 may be arranged as an irregular sinusoidal
line centered on a path that would be taken by a straight line
between the vertices 33 linked by the sinusoidal conductive metal
line 31.
[0059] In this example, the conductive lines 31 have varying
amplitudes and varying wavelengths of the sinusoids. As is
illustrated in FIG. 8, a sinusoidal conductive metal line 31a and a
sinusoidal conductive metal line 31b have different amplitudes and
wavelengths. The sinusoidal conductive metal line 31a may have a
longer wavelength and a smaller amplitude than the sinusoidal
conductive metal line 31b. A sinusoidal conductive metal line 31c
may have a shorter wavelength than sinusoidal conductive metal line
31b. The sinusoidal conductive metal line 31c may have sections 31e
and 31f with different amplitudes. The sections 31e of the
sinusoidal conductive metal line 31c have a smaller amplitude than
the sections 31f of the sinusoidal conductive metal line 31c. A
sinusoidal conductive metal line 31d may have sections with
different wavelengths and different amplitudes. The sinusoidal
conductive metal line 31d may have sections 31g and 31h with
different wavelengths. Section 31g of the sinusoidal conductive
metal line 31d may have a shorter wavelength than section 31h of
sinusoidal conductive metal line 31d. Further, section 31g of
sinusoidal conductive metal line 31d may have sections 31j and 31k
with different amplitudes. Section 31j may have a smaller amplitude
than section 31k.
[0060] As shown, the sinusoidal conductive lines in FIG. 8 may have
three different wavelengths and two different amplitudes. In other
examples, the sinusoidal conductive lines may have other numbers of
different wavelengths and other numbers of different
amplitudes.
[0061] In other examples, a phase change between the sinusoidal
shapes of the sinusoidal conductive lines where the sinusoidal
conductive lines interconnect at connection points may be
varied.
[0062] A portion of another electrode pattern 34 is shown in FIG.
9. For convenience, the drawing shows one vertex and two sinusoids,
one on either side of the vertex, for the lines connect at the
vertex. In this example, the electrode pattern 34 may be formed by
sinusoidal conductive lines 35a to 35d arranged to interconnect at
a connection point 36 to define a conductive grid or mesh pattern
made up of an array of mesh cells. The connection point 36 of the
sinusoidal conductive lines 35a to 35d form a vertex of four of the
mesh cells. In FIG. 9, a single connection point 36 is shown,
together with parts of the sinusoidal conductive lines 35a to 35d
which interconnect at the connection point 36.
[0063] In the illustrated example, four sinusoidal conductive lines
35a to 35d and the connection point 36 of those four lines 35a to
35d may be part of an electrode pattern 34 defining an array of
substantially square shaped mesh cells arranged in a layer. As
discussed regarding the previous examples, the sinusoidal
conductive lines may be sinusoidal shapes extending to either side
of the path of a straight line extending between adjacent
connection points or vertices of the electrode pattern 34. In the
exemplary orientation, because the electrode pattern 34 may define
an array of substantially square shaped mesh cells, a sinusoidal
conductive metal line 35a and a sinusoidal conductive metal line
35c may extend to either side of the connection point 36 in one
direction and may be aligned with one another. Similarly, a
sinusoidal conductive metal line 35b and a sinusoidal conductive
metal line 35d may extend to either side of the connection point 36
in another direction and may be aligned with one another. The
sinusoidal metal lines 35a and 35c extend perpendicularly to the
sinusoidal metal lines 35b and 35d.
[0064] In the example, the sinusoidal waveform of the conductive
metal line 35a and the sinusoidal conductive metal line 35c may be
in phase where the two conductive lines 35a and 35c meet at the
connection point 36. Similarly, the sinusoidal waveform of the
conductive metal line 35b and the sinusoidal waveform of the
conductive metal line 35d may be in phase where the two conductive
lines 35b and 35d meet at the connection point 36.
[0065] An example of a portion of another electrode pattern 37 is
shown in FIG. 10. In this illustrated example, the electrode
pattern 37 may be formed by a sinusoidal waveform of the conductive
lines 39a to 39d arranged to interconnect at a connection point 38
to define a conductive grid or mesh pattern made up of an array of
substantially square mesh cells. The connection point 38 of the
sinusoidal waveform of the conductive lines 39a to 39d forms a
vertex of four of the substantially square shaped mesh cells. In
FIG. 10, a single connection point 38 is shown, together with parts
of the conductive lines 39a to 39d which interconnect at the
connection point 38.
[0066] In FIG. 10, four sinusoidal waveforms of the conductive
lines 39a to 39d may be interconnected at the connection point 38.
In the illustrated example, a sinusoidal waveform of the conductive
metal line 39a and a sinusoidal waveform of the conductive metal
line 39c may be in phase where the two conductive lines 39a and 39c
meet at the connection point 38. In contrast, a sinusoidal waveform
of the conductive metal line 39b and a sinusoidal waveform of the
conductive metal line 39d may be in anti-phase, or 180.degree. out
of phase, where the two conductive lines 39b and 39d meet at the
connection point 38.
[0067] In FIG. 9, the sinusoidal conductive lines may be arranged
to be in phase where the sinusoidal conductive lines meet at
connection points in the mesh pattern. In FIG. 10, the sinusoidal
conductive lines 39a to 39d may be arranged to be in anti-phase
where the sinusoidal conductive lines meet at some of the
connection points 38 in the mesh pattern. In other examples, the
sinusoidal conductive lines 39a to 39d may be arranged to be in
anti-phase where the sinusoidal conductive lines meet at all of the
connection points in the mesh pattern.
[0068] In other examples, the width of the conductive lines may be
varied along their length.
[0069] A portion of another electrode pattern 40 is shown in FIG.
11. In this example, the electrode pattern 40 may include a
sinusoidal conductive metal line 41. The sinusoidal conductive
metal line 41 may have narrow sections 41a and broader sections
41b. The sinusoidal conductive metal line 41 may have a tapering
width between the narrow sections 41a and broader sections 41b. In
other examples, the width can vary non-linearly along the length of
the sinusoidal conductive metal line 41.
[0070] A portion of another electrode pattern 42 is shown in FIG.
12. In this illustrated example, the electrode pattern 42 may be
formed by sinusoidal conductive lines 43 arranged to interconnect
at a connection point 44 to define a conductive grid or mesh
pattern made up of an array of mesh cells. The connection point 44
of the sinusoidal conductive lines 43 forms a vertex of four of the
shapes. In FIG. 12, a single connection point 44 is shown, together
with parts of the sinusoidal conductive lines 43 which interconnect
at the connection point 44.
[0071] In FIG. 12, each of the four sinusoidal conductive lines 43
may be relatively narrow at the connection point 44, and relatively
broad away from the connection point 44. Each of the sinusoidal
conductive lines 43 may have a tapered section which widens in a
direction extending away from the connection point 44.
[0072] The examples shown in FIG. 11 and FIG. 12 may be combined.
For example, the sinusoidal conductive lines may vary in width
along their length and may be relatively narrow where the
sinusoidal conductive lines interconnect at a connection point.
[0073] In the examples of FIG. 11 and FIG. 12, the conductive lines
may be sinusoidal conductive lines. In other examples, the
conductive lines could have other geometries. In some examples, the
conductive lines which vary in width along their length and/or the
conductive lines which may be narrowed where the conductive lines
interconnect could be straight conductive lines.
[0074] FIG. 13 illustrates a portion of an exemplary electrode
pattern 50 which may be used in the touch position-sensing panel 1.
The exemplary electrode pattern may be used to form either
electrodes 4(X) and 5(Y). In the illustrated example, the electrode
pattern 50 may be formed by a number of conductive lines 51
arranged to interconnect at connection points to define a
conductive grid or mesh pattern made up of an array of mesh cells
52. The connection points of the conductive lines 51 may be the
vertices 53 of the mesh cells 52. In the illustrated example, the
pattern of the conductive lines 51 and mesh cells 52 may be
determined by first arranging all of the vertices 53 of the mesh
cells 52 in a regular square array. When the vertices 53 are in
this square array, the mesh cells 52 may be square and the
electrode pattern 50 may be similar to the illustrated example of
FIG. 2.
[0075] The positions of some of the vertices 53 may vary. In the
example, a vertex 53a may be a short distance to the left from the
location 53b which would represent a regular square array. As is
shown in FIG. 13, this position of the vertex 53a may result in
distorted, non-square shapes of mesh cells 52a to 52d for which
vertex 53a is a vertex. In one example, a vertex 53c may be a short
distance downward and to the left from the location which the
vertex 53c would have occupied in the regular square array. As is
shown in FIG. 13, this displacement of the vertex 53c may further
distort the shape of mesh cell 52d for which vertices 53a and 53c
are both displaced away from positions corresponding to a square
shape. The displacement of vertex 53c also may distort the shape of
the mesh cells 52e to 52g for which the vertex 53c is displaced
from a position corresponding to square shapes for the cells 52e,
52g.
[0076] In another example, the displaced vertex 53a and vertex 53c
may be displaced by a random distance in a random direction, with
the distance constrained to be no more than a predetermined range
of distances. Thus, the vertex 53a may be constrained to be
displaced to a position somewhere inside a circle 54 centered on
the location 53b which the vertex 53a would have occupied in the
regular square array and having a radius substantially equal to the
predetermined maximum distance.
[0077] In some examples, the maximum displacement distance can be
selected as a proportion of the distance between the vertices 53 in
the regular square array. For example, the maximum displacement
distance may be less than 0.5 times the distance between the
vertices 53 in the regular square array. In one example, the
displacement distance may be 0.1 times the distance between the
vertices 53.
[0078] FIG. 13 shows vertices 53a and 53c displaced from positions
that would otherwise produce the regular square array. In other
examples, some or all of the vertices in an electrode pattern may
be displaced.
[0079] Both the distance and direction of displacement of a vertex
may be randomly selected. In some examples, the direction of
displacement may be randomly selected while the distance of
displacement may be a fixed distance. In one example, this fixed
distance of displacement may be approximately 0.1 times the spacing
of the vertices.
[0080] In some examples, the distance of displacement may be varied
in relation to the direction of displacement. In other examples,
the amount of the variation may be varied based on the geometry of
the array of vertices.
[0081] In some examples, the direction of displacement may be
constrained so that the vertices can be displaced from positions
corresponding to regular square shapes.
[0082] Although the lines appear as straight lines in the
illustration, between vertices, the lines may have any of the
sinusoidal shapes as discussed above relative to FIGS. 4-12.
[0083] Displacing the vertices of the electrode pattern away from
positions in a regular geometric array may reduce the visibility of
moire effects. Such moire effects may arise from interactions
between the repeat length or cell size of an electrode pattern
having vertices in a regular array and an element size of elements
in a display visible through the touch position sensing panel. Such
moire effects may arise from interactions between the repeat length
or cell size of an electrode pattern and a cell size of an LCD
display visible through the touch position sensing panel. Moire
effects may produce a repeated pattern across the touch position
sensing panel. Such repetitive interference patterns are readily
perceived by the human eye.
[0084] As the deviation from regularity of a pattern of electrodes
increases, the scattering of light increases. For example, Table 1
shows data from a Fast Fourier Transform (FFT) analysis of a mesh
having a certain geometry. The FFT determines the number of angles
formed by the reflection of light on a cell. As can be seen in the
Table, as the randomness of the shape increases, a corresponding
increase in angles occurs.
TABLE-US-00001 TABLE 1 FFT analysis of geometric shapes Shape
Number of angles One pixel 2 Equilateral Diamond 4 2 Diamonds of
unequal height 8 4 diamonds with randomized 32 vertices one diamond
with curved lines >32 four diamonds with randomized >>32
curves
[0085] However, the randomization of the lines should be balanced
by the increase of the amount of wiring in the electrode due. The
increased amount of wiring may cause for less transmittance of
light through the panel.
[0086] FIG. 14 illustrates a portion of an exemplary electrode
pattern 55 which may be used in the touch position-sensing panel 1.
The exemplary electrode pattern may be used to form either
electrodes 4(X) and 5(Y). In the illustrated example, the electrode
pattern 55 may be formed by a number of conductive lines 56
arranged to interconnect at connection points to define a
conductive grid or mesh pattern made up of an array of mesh cells
57. The connection points of the conductive lines 56 may be the
vertices 58a to 58d of the mesh cells 57. In the example, the
pattern of the conductive lines 56 and mesh cells 57 may be
determined by selecting locations of a first group of vertices 58a.
As is shown, the first group of vertices 58a may be uniformly
spaced in a straight line. A second group of vertices 58b may then
be selected at locations derived from the locations of the first
group of vertices in a random manner.
[0087] As is shown in FIG. 14, this random selection may be carried
out by randomly selecting a distance between each one of the
vertices 58a and vertices 58b. Each of vertices 58b may be
connected to one of vertices 58a by a conductive metal line 56.
Thus, the distances between each one of the vertices 58a and each
of the vertices 58b may be random.
[0088] The locations of vertices 58c may then be selected by
repeating the random selection process based on the locations of
vertices 58b. In some examples, the random selection process may be
carried out by randomly selecting a distance between each one of
the vertices 58b and each of the vertices 58c. Each vertex 58c may
be connected to one of the vertices 58b by a conductive metal line
56. Thus, the distances between each one of the vertices 58b and
vertices 58c may be random.
[0089] This selection process may then be repeated in an iterative
manner until all of the selected area of the exemplary electrode
pattern 55 has been populated with vertices 58a to 58d
interconnected by conductive lines 56.
[0090] As a result of this iterative process of selecting locations
of the vertices 58a to 58d the mesh cells 57 making up the
electrode pattern 55 have random shapes and sizes. In some
examples, while the shapes comprising the mesh cells 57 may be
random, the variations in the areas of the mesh cells 57 are
minimized. For example, the variations in the areas of the mesh
cells 57 from a mean mesh cell area of electrode pattern 55 are
within 50%.
[0091] The randomly selected distances between vertices may be
selected from a range having predetermined upper and lower limits.
The predetermined upper and lower limits may be set at least in
part based on the distances between the already located
vertices.
[0092] In the illustrated example, the locations of the vertices
and the conductive lines may be selected before the conductive
lines are formed on the substrate.
[0093] In some examples, the conductive lines may be formed of
copper with a width in the range approximately 1 .mu.m to
approximately 10 .mu.m. In one example, the electrode pattern 10 is
arranged so that no more than approximately 5% of the surface of
the touch position-sensing panel may be covered by the conductive
lines 56.
[0094] In FIG. 14, the vertices 58a to 58c may be arranged in a
mesh pattern such that each vertex may be connected to four other
vertices by four conductive lines 56. The vertices 58a to 58c may
be initially arranged in an array of other regular trapezoid
shapes. In one example, the vertices 58a to 58c may be arranged to
define a mesh pattern such that each vertex is connected to another
number of other vertices.
[0095] In other examples, different methods of randomly selecting
the locations of the vertices may be used.
[0096] In some examples, the vertex locations determined by the
iterative random selection of vertex locations may be checked to
prevent conflicting vertex locations to occur. In some examples,
when vertex locations conflict, the random selection process may be
repeated until the vertex locations do not conflict. Examples of
conflicting vertex locations include two or more vertices having
one location, or vertex locations in which the conductive lines
linking the vertices cross one another.
[0097] In some examples, the electrode pattern 55 may be
iteratively defined by starting from one edge of a display or an
electrode area and iteratively defining the positions of vertices
until another edge of the display or electrode area is reached.
[0098] In FIG. 14, the conductive lines defining the electrode
pattern may be shown as straight lines for simplicity and to allow
easy understanding of the illustrated examples. In other examples,
the conductive lines may be shaped according to any of the
illustrated examples of FIGS. 4 to 12, either singly or in
combination.
[0099] In some examples, the electrode patterns produced according
to the illustrated examples of FIGS. 13 and 14 may be checked to
ensure that the random selection of the vertex locations has not
inadvertently resulted in an electrode pattern having linear or
periodically repeating elements in the electrode pattern,
particularly linear elements extending in a direction which may be
horizontal, vertical, or at 45.degree. with respect to an
orientation of a display which is to be visible through the touch
position sensing panel, and vertices or conductive lines which are
too closely spaced. This randomization may prevent interference
resulting from positioning of the vertices in relation to the
pixels of an LCD.
[0100] As discussed regarding the example shown in FIG. 3, a touch
position sensing panel may have two electrode layers with
respective electrode patterns so that the electrode patterns
overlay one another. Any of the examples shown in FIGS. 4 to 14 may
be used for either one or both of the electrode layers that may be
implemented using narrow metal conductive lines.
[0101] In some examples using mesh metal patterns for both
electrode layers, the respective electrode patterns of the two
electrode layers may be arranged so that the vertices of one of the
electrode patterns are positioned at locations substantially
corresponding to centers of mesh cells of the other electrode
pattern. As a result of this arrangement of the two electrode
patterns, the conductive lines of the two electrode patterns may be
distributed more evenly across the touch position-sensing panel. In
FIGS. 13 and 14, one of the electrode patterns may have vertex
locations determined randomly according to the illustrated examples
of FIG. 13 or 14. The centroids of area of the mesh cells defined
by the randomly determined vertex locations of this one of the
electrode patterns may define the locations of the vertices of the
other electrode patterns.
[0102] For example, the pattern in FIG. 3a may be overlayed with
the pattern of FIG. 14, to create a pattern consisting of rhomboid
shapes of FIG. 3, the centroids of which are connected by the
vertices of the pattern of FIG. 14. Since the connecting lines of
FIG. 14 may be generated at the mid point of the lines of FIG. 3,
all lines of FIG. 3 run equidistant or in parallel between the
lines of FIG. 14 to minimize capacitance. They also intersect at 90
degrees. However, the vertex locations of other electrode patterns
may nevertheless be randomly determined, albeit indirectly.
[0103] Arranging for vertices of one of the electrode patterns to
be positioned at locations substantially corresponding to centers
of mesh cells of the other electrode pattern may spread the
conductive lines more evenly across the touch position sensing
panel, and may reduce visible reductions in display brightness.
[0104] In some examples, the respective electrode patterns of the
two electrode layers may be arranged so that where conductive lines
in the two respective electrode patterns of the two electrode
layers cross over one another, the conductive lines cross at an
approximately 90.degree. angle. In some examples, it may not be
possible to arrange for some conductive lines to cross at a
90.degree. angle and the conductive lines may be arranged to cross
at as close to a 90.degree. angle as is practicable. The conductive
lines are arranged in curved shapes according to the examples shown
in FIGS. 4 to 12. The angle at which conductive lines in the two
respective electrode patterns of the two electrode layers cross
over may be controlled by adjusting one or more of the wavelength,
amplitude and phase of the curved shapes of one or both of the
conductive lines.
[0105] Arranging for conductive lines in the two respective
electrode patterns of the two electrode layers to cross over one
another at, or close to, an approximately 90.degree. angle may
reduce mutual capacitance between the conductive lines. Arranging
for conductive lines in the two respective electrode patterns of
the two electrode layers to cross over one another at, or close to,
an approximately 90.degree. angle may prevent two closely spaced
parallel or oblique lines to be perceived as a single thicker line.
Arranging for conductive lines in the two respective electrode
patterns of the two electrode layers to cross over one another at,
or close to, an approximately 90.degree. angle may spread the
conductive lines more evenly across the touch position sensing
panel, and may reduce visible reductions in display brightness.
[0106] In some examples, the respective electrode patterns of the
two electrode layers may be arranged so that where conductive lines
in the two respective electrode patterns of the two electrode
layers cross over one another the phase and/or width of the
conductive lines may be controlled according to the examples shown
in FIGS. 9 to 12. The cross over point of conductive lines in the
respective electrode patterns of the different electrode layers may
be treated in a similar way as a connection point in the examples
shown in FIGS. 9 to 12.
[0107] Reducing the width of the conductive lines in the respective
electrode patterns in the two electrode layers where the conductive
lines cross over may reduce visible reductions in display
brightness at the interconnections. Such reductions in display
brightness may be visible where constant width conductive lines
cross over as there may be a concentration of conductive metal at
the cross over point. Reducing the width of the sinusoidal
conductive lines where the sinusoidal conductive lines cross over
makes the distribution of the conductive metal across a touch
position sensing panel more even, reducing the visibility of
differences in display brightness.
[0108] The above examples refer to two electrode layers. The above
examples could be extended to only one layer, or to three or more
electrode layers. If three or more electrode layers are present,
the vertices of the electrode patterns of the different layers may
be arranged to spread the vertices approximately evenly across the
touch position-sensing panel. Placing the vertices of some of the
electrode patterns at locations corresponding to centers of mesh
cells of other electrode patterns may not be effective for three or
more electrode layers.
[0109] In some examples where a touch position sensing panel is
intended to overlay a display having a set display cell size such
as an LCD or LED display, the dimensions of the electrode pattern
or patterns used may be selected, at least in part, based upon this
set cell size of the display. This may allow visual interactions
between the display and the touch position sensing panel to be
minimized.
[0110] The illustrated examples described above relate to conductor
elements and patterns of copper. However, other material may be
used. For example, other metals suitable for use as wire pattern
material.
[0111] The electrodes discussed above may also be incorporated into
devices using a self-capacitance drive approach.
[0112] Various modifications may be made to the examples described
in the foregoing, and any related examples may be applied in
numerous applications, some of which have been described herein. It
is intended by the following claims to claim any and all
applications, modifications and variations that fall within the
true scope of the present disclosure.
* * * * *