Mesh Designs for Touch Sensors
In one embodiment, an apparatus includes a touch sensor that includes a mesh of conductive material configured to extend across a display that includes multiple pixels. Each of the pixels has a first pixel pitch (PP x ) along a first axis and a second pixel pitch (PP y ) along a second axis that is substantially perpendicular to the first axis. The first pixel pitch is a distance between corresponding features of two adjacent pixels along the first axis, and the second pixel pitch is a distance between corresponding features of two adjacent pixels along the second axis. The mesh includes first lines of conductive material that are substantially parallel to each other and second lines of conductive material that are substantially parallel to each other. The first lines are configured to extend across the display at a first angle relative to the first axis.
1 . An apparatus that comprises:
a touch sensor that comprises a mesh of conductive material configured to extend across a first display, wherein:
the first display comprises a plurality of pixels, wherein:
each of the pixels has a first pixel pitch (PP x ) along a first axis and a second pixel pitch (PP y ) along a second axis that is substantially perpendicular to the first axis;
the first pixel pitch is a distance between corresponding features of two adjacent pixels along the first axis; and
the second pixel pitch is a distance between corresponding features of two adjacent pixels along the second axis;
the mesh comprises first lines of conductive material that are substantially parallel to each other and second lines of conductive material that are substantially parallel to each other;
the first lines are configured to extend across the first display at a first angle relative to the first axis, wherein the first angle is within 1° of the arctangent of
[
3
m
×
PP
y
PP
x
]
,
wherein m is an integer;
the second lines are configured to extend across the first display at a second angle relative to the first axis, wherein the second angle is within 1° of the arctangent of
[
3
n
×
PP
y
PP
x
]
,
wherein n is an integer;
first lines that are adjacent to each other are separated from each other along the first axis by a first-line separation distance that is within 1% of
(
p
3
×
q
×
PP
x
)
,
wherein p and q are integers;
second lines that are adjacent to each other are separated from each other along the first axis by a second-line separation distance that is within 1% of
(
r
3
×
s
×
PP
x
)
,
wherein r and s are integers;
a portion of one or more of the first or second lines comprises a sinusoidal variation with a peak-to-peak amplitude of less than or equal to 30 μm; and
the mesh of conductive material has a metal density of 3% to 5%; 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:
the first pixel pitch is within 2% of the second pixel pitch;
m is equal to 5;
the first angle is within 1° of 30.96°;
n is equal to 2; and
the second angle is within 1° of 56.31°.
3 . The apparatus of claim 1 , wherein:
the first pixel pitch is within 2% of the second pixel pitch;
m is equal to 4;
the first angle is within 1° of 36.87°;
n is equal to 2; and
the second angle is within 1° of 56.31°.
4 . The apparatus of claim 1 , wherein:
p is equal to 12;
q is equal to 1;
the first-line separation distance is within 1% of 4×PP x ;
r is equal to 10;
s is equal to 1; and
the second-line separation distance is within 1% of
10
3
×
PP
x
.
5 . The apparatus of claim 1 , wherein:
p is equal to 9;
q is equal to 1;
the first-line separation distance is within 1% of 3×PP x ;
r is equal to 14;
s is equal to 3; and
the second-line separation distance is within 1% of
14
9
×
PP
x
.
6 . The apparatus of claim 1 , wherein:
p is equal to 31;
q is equal to 2;
the first-line separation distance is within 1% of
31
6
×
PP
x
;
r is equal to 17;
s is equal to 2; and
the second-line separation distance is within 1% of
17
6
×
PP
x
.
7 . The apparatus of claim 1 , wherein:
p is equal to 41;
q is equal to 6;
the first-line separation distance is within 1% of
41
18
×
PP
x
;
r is equal to 14;
s is equal to 3; and
the second-line separation distance is within 1% of
14
9
×
PP
x
.
8 . The apparatus of claim 1 , wherein:
p is equal to 12;
q is equal to 1;
the first-line separation distance is within 1% of 4×PP x ;
r is equal to 8;
s is equal to 1; and
the second-line separation distance is within 1% of
8
4
×
PP
x
.
9 . The apparatus of claim 1 , wherein:
p is equal to 7;
q is equal to 1;
the first-line separation distance is within 1% of
7
3
×
PP
x
;
r is equal to 7;
s is equal to 2; and
the second-line separation distance is within 1% of
7
6
×
PP
x
.
10 . The apparatus of claim 1 , wherein:
p is equal to 19;
q is equal to 3;
the first-line separation distance is within 1% of
19
9
×
PP
x
;
r is equal to 14;
s is equal to 3; and
the second-line separation distance is within 1% of
14
9
×
PP
x
.
11 . The apparatus of claim 1 , wherein:
p is equal to 12;
q is equal to 1;
the first-line separation distance is within 1% of 4×PP x ;
r is equal to 13;
s is equal to 2; and
the second-line separation distance is within 1% of
13
6
×
PP
x
.
12 . The apparatus of claim 1 , wherein the first and second lines of conductive material each have a width between 2.5 μm and 3.5 μm.
13 . The apparatus of claim 1 , wherein the first and second lines of conductive material each have a width between 4.5 μm and 5.5 μm.
14 . The apparatus of claim 1 , wherein the first and second lines of conductive material form a plurality of mesh cells, each mesh cell having a diagonal length between 265 μm and 340 μm.
15 . The apparatus of claim 1 , wherein:
the first axis is horizontal;
the second axis is vertical;
the first pixel pitch along the first axis is a pixel width; and
the second pixel pitch along the second axis is a pixel height.
16 . A touch sensor that comprises:
a mesh of conductive material configured to extend across a first display, wherein:
the first display comprises a plurality of pixels, wherein:
each of the pixels has a first pixel pitch (PP x ) along a first axis and a second pixel pitch (PP y ) along a second axis that is substantially perpendicular to the first axis;
the first pixel pitch is a distance between corresponding features of two adjacent pixels along the first axis; and
the second pixel pitch is a distance between corresponding features of two adjacent pixels along the second axis;
the mesh comprises first lines of conductive material that are substantially parallel to each other and second lines of conductive material that are substantially parallel to each other;
the first lines are configured to extend across the display at a first angle relative to the first axis, wherein the first angle is within 1° of the arctangent of
[
3
m
×
PP
y
PP
x
]
,
wherein m is an integer;
the second lines are configured to extend across the display at a second angle relative to the first axis, wherein the second angle is within 1° of the arctangent of
[
3
n
×
PP
y
PP
x
]
,
wherein n is an integer;
first lines that are adjacent to each other are separated from each other along the first axis by a first-line separation distance that is within 1% of
(
p
3
×
q
×
PP
x
)
,
wherein p and q are integers;
second lines that are adjacent to each other are separated from each other along the first axis by a second-line separation distance that is within 1% of
(
r
3
×
s
×
PP
x
)
,
wherein r and s are integers;
a portion of one or more of the first or second lines comprises a sinusoidal variation with a peak-to-peak amplitude of less than or equal to 30 μm; and
the mesh of conductive material has a metal density of 3% to 5%.
17 . The touch sensor of claim 16 , wherein:
the first pixel pitch is within 2% of the second pixel pitch;
m is equal to 5;
the first angle is within 1° of 30.96°;
n is equal to 2; and
the second angle is within 1° of 56.31°.
18 . The touch sensor of claim 16 , wherein:
the first pixel pitch is within 2% of the second pixel pitch;
m is equal to 4;
the first angle is within 1° of 36.87°;
n is equal to 2; and
the second angle is within 1° of 56.31°.
19 . The touch sensor of claim 16 , wherein the first and second lines of conductive material each have a width between 2.5 μm and 3.5 μm.
20 . A method comprising:
identifying, with respect to a first display, a first pixel pitch (PP x ) along a first axis and a second pixel pitch (PP y ) along a second axis that is substantially perpendicular to the first axis;
calculating a first angle to be within 1° of
[
3
m
×
PP
y
PP
x
]
,
the arctangent of wherein m is an integer;
calculating a second angle to be within 1° of the arctangent of
[
3
n
×
PP
y
PP
x
]
,
wherein n is an integer;
calculating a first-line separation distance to be within 1% of
(
p
3
×
q
×
PP
x
)
,
wherein p and q are integers;
calculating a second-line separation distance to be within 1% of
(
r
3
×
s
×
PP
x
)
,
wherein r and s are integers;
depositing on a substrate a mesh of conductive material configured to extend across the first display, wherein:
the first display comprises a plurality of pixels, wherein:
each of the pixels has the first pixel pitch (PP x ) along the first axis and the second pixel pitch (PP y ) along the second axis;
the first pixel pitch is a distance between corresponding features of two adjacent pixels along the first axis; and
the second pixel pitch is a distance between corresponding features of two adjacent pixels along the second axis;
the mesh comprises first lines of conductive material that are substantially parallel to each other and second lines of conductive material that are substantially parallel to each other;
the first lines are configured to extend across the display at the first angle relative to the first axis;
the second lines are configured to extend across the display at the second angle relative to the first axis;
first lines that are adjacent to each other are separated from each other along the first axis by the first-line separation distance;
second lines that are adjacent to each other are separated from each other along the first axis by the second-line separation distance;
a portion of one or more of the first or second lines comprises a sinusoidal variation with a peak-to-peak amplitude of less than or equal to 30 μm; and
the mesh of conductive material has a metal density of 3% to 5%; and
forming one or more electrodes of a touch sensor from the mesh of conductive material.
21 . The apparatus of claim 1 , wherein an optical transmission loss of the mesh is less than or equal to 5%.
22 . The apparatus of claim 1 , wherein the conductive material comprises copper or silver.
23 . The apparatus of claim 1 , wherein PP x and PP y are each between 50 μm and 300 μm.
24 . The apparatus of claim 1 , wherein the mesh of conductive material is further configured to extend across a second display, wherein the second display comprises pixels having pixel pitches within 2% of the corresponding first and second pixel pitches of the first display and each pixel of the second display comprises one or more sub-pixels having a sub-pixel height that is different from a sub-pixel height of sub-pixels of the first display.