(12)
`
`United States Patent
`Philipp et al.
`
`(10) Patent No.:
`(45) Date of Patent:
`
`US 9,632,628 B2
`Apr. 25, 2017
`
`USOO9632628B2
`
`(54) INTERDIGITATED TOUCHSCREEN
`ELECTRODES
`
`O O
`(75) Inventors: Harald Philipp, Hamble (GB); Esat
`Yilmaz, Chandler's Ford (GB)
`(73) Assignee: Atmel Corporation, San Jose, CA (US)
`
`(*) Notice:
`
`Subject to any disclaimer, the term of this
`patent is extended or adjusted under 35
`U.S.C. 154(b) by 437 days.
`(21) Appl. No.: 12/604,944
`
`(22) Filed:
`
`Oct. 23, 2009
`O
`O
`Prior Publication Data
`US 2011 FOO95990 A1
`Apr. 28, 2011
`
`(65)
`
`(2006.01)
`
`(51) Int. Cl.
`G06F 3/044
`(52) U.S. Cl.
`CPC .................................... G06F 3/044 (2013.01)
`(58) Field of Classification Search
`CPC ..................................................... GO6F 3/0488
`USPC .......................................................... 34.5/173
`See application file for complete search history.
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`Primary Examiner — Claire X Pappas
`Assistant Examiner — Robert Stone
`(74) Attorney, Agent, or Firm — Baker Botts L.L.P.
`
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`
`(57)
`
`ABSTRACT
`
`6,222,528 B1 ck
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`4/2011 Hotelling
`8,031,094 B2 10/2011 Hotelling
`
`A device includes a plurality of adjacent electrodes for a
`touch sensitive device. The electrodes run generally in a first
`direction. Adjacent electrodes are interdigitated to provide
`one or more interpolation sections of the electrodes. Touch
`sensitive devices may utilize Such interdigitated electrodes
`as drive electrodes, along with transverse sense electrodes
`formed over a display.
`25 Claims, 13 Drawing Sheets
`
`
`
`3.
`
`3.
`
`Petitioner STMICROELECTRONICS, INC.,
`Ex. 1009, IPR2021-01161 Page 1 of 21
`
`

`

`US 9,632,628 B2
`Page 2
`
`(56)
`
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`cambrios.com/200/DOD Release.htm>, (Apr. 12, 2010), 2 pgs.
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`and OLED Markets', online. retrieved Apr. 20, 2010). Retrieved
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`OOOO65.
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`U.S. Appl. No. 61/454.950, filed Mar. 21, 2011, Lynch.
`U.S. Appl. No. 61/454,894, filed Mar. 21, 2011, Rothkopf.
`First Office Action Issued by State Intellectual Property Office
`(China), regarding patent application 2010/10519970.4 (Chinese
`and English versions). Mar. 26, 2014.
`Second Office Action Issued by State Intellectual Property Office
`(China), regarding patent application 2010/10519970.4; Ref
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`lation), Apr. 17, 2015.
`
`“Cambrios Technologies Corporation Awarded Department of
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`
`* cited by examiner
`
`Petitioner STMICROELECTRONICS, INC.,
`Ex. 1009, IPR2021-01161 Page 2 of 21
`
`

`

`U.S. Patent
`
`Apr. 25, 2017
`
`Sheet 1 of 13
`
`US 9,632,628 B2
`
`Xo
`
`X
`
`6
`X+X N
`2
`\6)
`
`6)
`X+X N
`
`A5)
`
`55
`
`FIG. 1
`(PRIOR ART)
`
`
`
`Petitioner STMICROELECTRONICS, INC.,
`Ex. 1009, IPR2021-01161 Page 3 of 21
`
`

`

`U.S. Patent
`U.S. Patent
`
`Apr.25, 2017
`Apr. 25, 2017
`
`Sheet 2 of 13
`Sheet 2 of 13
`
`US 9,632,628 B2
`US 9,632,628 B2
`
`
`
`345 Xe
`
`(Xp +X))/2 ->-
`
`X
`
`x
`
`
`
`GX, +X,)/4--
`(X, + X,)/2--
`
`
`
`
`(X; + 3X,)/4--
`
`Xy
`
`FIG, 4
`FIG. 4
`
`Petitioner STMICROELECTRONICS, INC.,
`Ex. 1009, IPR2021-01161 Page 4 of 21
`
`Petitioner STMICROELECTRONICS, INC.,
`Ex. 1009, IPR2021-01161 Page 4 of 21
`
`

`

`U.S. Patent
`U.S. Patent
`
`Apr.25, 2017
`Apr. 25, 2017
`
`Sheet 3 of 13
`Sheet 3 of 13
`
`US 9,632,628 B2
`US 9,632,628 B2
`
` °
`
`A=B=C=D
`
`
`
`FIG 5
`
`Petitioner STMICROELECTRONICS, INC.,
`Ex. 1009, IPR2021-01161 Page 5 of 21
`
`Petitioner STMICROELECTRONICS, INC.,
`Ex. 1009, IPR2021-01161 Page 5 of 21
`
`

`

`U.S. Patent
`
`Apr. 25, 2017
`
`Sheet 4 of 13
`
`US 9,632,628 B2
`
`
`
`||||||
`U||
`
`'N DIDu
`
`FIG. 6
`
`Petitioner STMICROELECTRONICS, INC.,
`Ex. 1009, IPR2021-01161 Page 6 of 21
`
`

`

`U.S. Patent
`
`Apr. 25, 2017
`
`Sheet S of 13
`
`US 9,632,628 B2
`
`(6
`
`72
`
`2
`
`
`
`
`
`
`
`A.
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`n n n i? n
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`
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`f
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`
`
`
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`f
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`
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`
`
`illupi
`
`
`
`Did
`
`Petitioner STMICROELECTRONICS, INC.,
`Ex. 1009, IPR2021-01161 Page 7 of 21
`
`

`

`U.S. Patent
`U.S. Patent
`
`Apr.25, 2017
`Apr. 25, 2017
`
`Sheet 6 of 13
`Sheet 6 of 13
`
`US 9,632,628 B2
`US 9,632,628 B2
`
`R N
`
`2
`R28
`
`X
`X,
`
`X
`
`X;
`
`5
`81d
`
`2)
`BAO
`
`25
`825
`
`FIG. 8
`FIG. 8
`
`Petitioner STMICROELECTRONICS, INC.,
`Ex. 1009, IPR2021-01161 Page 8 of 21
`
`Petitioner STMICROELECTRONICS, INC.,
`Ex. 1009, IPR2021-01161 Page 8 of 21
`
`

`

`U.S. Patent
`U.S. Patent
`
`Apr.25, 2017
`Apr. 25, 2017
`
`Sheet 7 of 13
`Sheet 7 of 13
`
`US 9,632,628 B2
`US 9,632,628 B2
`
`900 ™“
`9. \
`
`Y
`Yo
`O
`
`Y
`Yy
`1
`
`Y
`Y,
`2
`
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`Y3
`3
`
`Y
`Y4
`4
`
`Y
`Ys;
`S-15
`MND
`92
`920
`
`FIG 9
`FIG. 9
`
`Petitioner STMICROELECTRONICS, INC.,
`Ex. 1009, IPR2021-01161 Page 9 of 21
`
`Petitioner STMICROELECTRONICS, INC.,
`Ex. 1009, IPR2021-01161 Page 9 of 21
`
`

`

`U.S. Patent
`
`
`
`Apr. 25, 2017
`Apr. 25, 2017
`
`U.S. Patent
`
`Sheet 8 of 13
`Sheet 8 of 13
`
`US 9,632,628 B2
`US 9,632,628 B2
`
`Petitioner STMICROELECTRONICS, INC.,
`Ex. 1009, IPR2021-01161 Page 10 of 21
`
`Petitioner STMICROELECTRONICS, INC.,
`Ex. 1009, IPR2021-01161 Page 10 of 21
`
`

`

`U.S. Patent
`U.S. Patent
`
`Apr.25, 2017
`Apr. 25, 2017
`
`Sheet 9 of 13
`Sheet 9 of 13
`
`US 9,632,628 B2
`US 9,632,628 B2
`
`A3
`(U3
`
`2)
`1120
`
`(WW
`
`>
`
`MLRAARAA S
`N.
`1135 I™OSOXAANAY |.
`
`(132
`
`
`
`X2
`
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`AR
`
`A6
`(06
`
`FIG. 11
`
`Petitioner STMICROELECTRONICS, INC.,
`Ex. 1009, IPR2021-01161 Page 11 of 21
`
`Petitioner STMICROELECTRONICS, INC.,
`Ex. 1009, IPR2021-01161 Page 11 of 21
`
`

`

`U.S. Patent
`
`Apr. 25, 2017
`
`Sheet 10 of 13
`
`US 9,632,628 B2
`
`122
`
`1222
`
`122,
`
`122A
`
`1225
`
`1226
`
`N. N. N
`
`A2
`
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`
`/N
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`
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`
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`
`FIG, 12A
`
`
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`26
`
`229
`
`23
`
`23
`
`22,
`
`233
`
`23A
`
`FIG, 12B
`
`Petitioner STMICROELECTRONICS, INC.,
`Ex. 1009, IPR2021-01161 Page 12 of 21
`
`

`

`U.S. Patent
`
`Apr. 25, 2017
`
`Sheet 11 of 13
`
`US 9,632,628 B2
`
`p1 3)
`
`Y3
`
`YO
`
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`
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`
`Y2
`
`5
`
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`
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`
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`
`FIG, 13
`
`Petitioner STMICROELECTRONICS, INC.,
`Ex. 1009, IPR2021-01161 Page 13 of 21
`
`

`

`U.S. Patent
`
`Apr. 25, 2017
`
`Sheet 12 of 13
`
`US 9,632,628 B2
`
`YO
`
`
`
`Y1
`
`3)
`
`Y2
`
`5
`
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`
`N N N ANN N
`o, N N N N N N
`N N N
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`N N N N N N N
`NNN
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`
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`
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`
`FIG, 14
`
`Petitioner STMICROELECTRONICS, INC.,
`Ex. 1009, IPR2021-01161 Page 14 of 21
`
`

`

`U.S. Patent
`
`Apr. 25, 2017
`
`Sheet 13 of 13
`
`US 9,632,628 B2
`
`N - ,
`152- .
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`
`
`
`Petitioner STMICROELECTRONICS, INC.,
`Ex. 1009, IPR2021-01161 Page 15 of 21
`
`

`

`US 9,632,628 B2
`
`1
`INTERDIGITATED TOUCHSCREEN
`ELECTRODES
`
`BACKGROUND
`
`Touchscreen displays are able to detect a touch such as by
`a finger or stylus within an active or display area. Use of a
`touchscreen as part of a display enables a user to interact
`with an electronic application by touching the touchscreen.
`The display may present images to the user. Such images
`may include user interface constructs such as different
`buttons,
`images, or other regions that can be selected,
`manipulated, or actuated by touch. Touchscreens can there-
`fore provide an effective user interface for cell phones, GPS
`devices, personal digital assistants (PDAs), computers, ATM
`machines, appliances, and other devices.
`Touchscreens use various technologies to sense touch
`from a fingeror stylus, such asresistive, capacitive, infrared,
`and acoustic sensors. In capacitive sensor based touch-
`screens, a touch changes a capacitance at a node in an array
`of electrodes overlaying the display device. Capacitive
`touchscreens often use two separate layers of transverse
`electrodes arranged as an X-Y matrix separated by a dielec-
`tric layer. The regions proximate the intersections of the
`transverse electrodes form sensing nodes, which are indi-
`vidually accessed by a sequential scanning process to deter-
`mine the location of one or more touches. Transparent
`electrodes made from indium tin oxide (ITO) or transparent
`conductive polymers, or fine metal lines may be used to
`form the array of nodes overa liquid crystal display (LCD).
`Images on the LCD display can be seen through the trans-
`parent capacitive touchscreens.
`LCDdisplays may emit alternating electric fields that can
`interfere with touch detection. In some prior touchscreen
`devices, an additional solid ITO layer was used as a shield
`between the electrodes layers and the LCD. This added
`significant expense in materials as well as processing. In
`other prior touchscreen devices, a layer of electrodes closest
`to the LCD,referred to as drive electrodes, was made up of
`wide electrodes that substantially covered the LCD, provid-
`ing a shield for a top layer of electrodes referred to as sense
`electrodes. Some prior devices utilized intermediate drive
`electrodes 150, 155 as shown in FIG. 1, along with a
`network of resistors 160 to couple the intermediate drive
`electrodes from the primary X drive signals as shown. The
`use of intermediate drive electrodes allowed a reduction in
`
`the number of X drive lines directly driven by the control
`circuitry, reducing the complexity and pin count of the
`control circuitry and the number of required connection
`wires. However, the resistors required space, increasedcost,
`and also degraded manufacturing yield.
`It also created
`additional loading on the control circuitry, dissipated more
`power, and degraded the shielding capability of the elec-
`trodes against LCD noise dueto raised effective impedance
`levels of the electrodes caused by the introduction of the
`dividerresistors.
`
`SUMMARY
`
`A device includes a plurality of adjacent electrodes for a
`touch sensitive device. The electrodes run generally in one
`direction. Adjacent electrodes are interdigitated to provide
`one or more interpolated sections of the electrodes. Touch
`sensitive devices mayutilize interdigitated drive electrodes
`along with transverse sense electrodes formed over a dis-
`play.
`
`10
`
`15
`
`20
`
`25
`
`30
`
`35
`
`40
`
`45
`
`50
`
`55
`
`60
`
`65
`
`2
`BRIEF DESCRIPTION OF THE DRAWINGS
`
`FIG.1 illustrates a prior art drive electrode pattern.
`FIG.2 illustrates an interdigitated drive electrode pattern
`with interpolation for a touchscreen according to an example
`embodiment.
`FIG.3 illustrates an interdigitated drive electrode pattern
`with triangular interpolation for a touchscreen according to
`an example embodiment.
`FIG. 4 illustrates a triangular pattern of interdigitated
`drive electrodes having an elongated cross-section with
`multiple interpolative zones, according to an example
`embodiment.
`FIG.5 illustrates an interdigitated drive electrode pattern
`with multiple stepped interpolative zones for a touchscreen
`according to an example embodiment.
`FIG.6 illustrates an interdigitated drive electrode pattern
`on onelayer and sense electrodes with crossbars on a second
`layer according to an example embodiment.
`FIG.7 illustrates an interdigitated drive electrode pattern
`on one layer with multiple stepped interpolation, and sense
`electrodes with crossbars on a second layer, according to an
`example embodiment.
`FIG.8 illustrates an alternative interdigitated drive elec-
`trode pattern with interpolation for a touchscreen according
`to an example embodiment.
`FIG. 9 illustrates a receive electrode pattern for the
`alternative interdigitated drive electrode pattern of FIG. 8.
`FIG. 10 illustrates the alternative interdigitated drive
`electrode pattern with interpolation along with sense elec-
`trodes for a touchscreen according to an example embodi-
`ment.
`
`FIG. 11 illustrates a portion of an interdigitated fine line
`drive electrode pattern with interpolation for a touchscreen
`according to an example embodiment.
`FIG. 12A illustrates an interpolated drive region of the
`pattern of FIG. 11 according to an example embodiment.
`FIG. 12B illustrates an alternative interpolated drive
`region of the pattern of FIG. 11 according to an example
`embodiment.
`
`FIG. 13 illustrates a sense electrode pattern according to
`an example embodiment.
`FIG.14 illustrates a fine line drive electrode pattern with
`interpolation including sense electrodes for a touchscreen
`according to an example embodiment.
`FIG. 15 illustrates a touch sensitive device overlaying a
`display panel, according to an example embodiment.
`FIG. 16 illustrates a cellular telephone having a touch-
`screen display, consistent with an example embodiment of
`the invention
`
`DETAILED DESCRIPTION
`
`Multiple embodiments are described. In a first embodi-
`ment, a plurality of adjacent drive electrodes for a touch-
`screen run generally in a first direction. Adjacent drive
`electrodes may have projections that extend towards each
`other. The projections may be interleaved or interdigitated to
`provide one or more interpolated sections of the drive
`electrodes where the projections are interdigitated. The drive
`electrodes may be solid fill conductive areas in one set of
`embodiments, and fine line drive electrodes in anotherset of
`embodiments. In further embodiments, sense electrodes may
`be interdigitated.
`FIG.2 illustrates an interdigitated drive electrode pattern
`200 with interpolation for a touchscreen according to an
`example embodiment. A drive electrode 210 runs longitu-
`
`Petitioner STMICROELECTRONICS, INC.,
`Ex. 1009, IPR2021-01161 Page 16 of 21
`
`Petitioner STMICROELECTRONICS, INC.,
`Ex. 1009, IPR2021-01161 Page 16 of 21
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`US 9,632,628 B2
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`10
`
`15
`
`30
`
`35
`
`40
`
`25
`
`3
`dinally in a first direction. A first portion of the drive
`electrode 210 is continuous for a desired width (shown in
`bracket), and corresponds to an Xo drive line coupled to
`drive circuitry (not shown). A second portion of the drive
`electrode 210 includes a plurality of projections or steps 215
`(shown in bracket). The projections may be substantially the
`same width as the width of the first portion of the drive
`electrode 210, ie, distances shown as A and B may be the
`same in order to provide for equal spacing of the interpo
`lative Zones along the vertical axis of the pattern 200.
`An electrode 225 is adjacent to drive electrode 210 and
`also has a continuous portion for a desired width, which may
`be the same width as the continuous portion of electrode
`210. The continuous portion of electrode 225 corresponds to
`drive line X, shown in bracket, that may be coupled to drive
`circuitry. Second electrode 225 also contains steps or pro
`jections 230 that are interdigitated with projections 215 and
`are separated by a gap 237. Together, the interdigitated
`projections result in an interpolated drive section, which is
`driven by both drive lines X and X, shown in bracket,
`which on average has 50% of its electric field driven by X
`and 50% by X Second electrode 225 in one embodiment
`includes further projections 240 on a second side for inter
`digitation with projections 250 from a further adjacent X
`drive electrode.
`The interdigitated sections shown in brackets between X
`and X, and X and X, designated as (XX)/2 and
`(X+X)/2 respectively emit a mixture of fields driven by the
`respective drive lines with a granularity approximating
`width 260; if this width is smaller than the width of a finger
`print area on an overlaying panel, the response of the merged
`fields can represent a reasonably interpolated signal which
`can be used to locate a touch intermediate the continuous
`electrode strips. This effect is aided by the fact that an
`overlying dielectric panel (not shown) tends to mix or blend
`adjacent fields in boundary regions, thereby smoothing the
`transitional response to a finger. If the width 260 is too wide,
`and the overlying panel too thin, then it would be possible
`that the linearity of the touch panel would be adversely
`affected by localized distortions.
`In one embodiment, there is a near one to one relationship
`between non-interpolated drive sections or simply drive
`sections and interpolated drive sections, with one interpo
`lated drive section formed by the interdigitated steps or
`projections between adjacent drive sections. The drive and
`interpolated drive sections in one embodiment, may be made
`of filled areas of metal, conductive plastic, ITO or other form
`of conductive material. If the touchscreen is to be positioned
`over a display, the conductive material may be substantially
`transparent to allow visibility of the display beneath the
`touchscreen. When the electrodes are formed of filled areas
`of conductive material, they may act as an electric field
`shield between a display and sense electrodes.
`In one embodiment, a 50/50 proportional mixture of
`adjacent X drive lines create an intermediate section to
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`increase the X section count without adding additional drive
`lines. Given N. X lines directly driving N electrodes, the
`50/50 proportional mixture provides an additional N-1
`intermediate sections without increasing beyond N actual
`connections to drive circuitry. In one embodiment, resistors
`previously used to provide intermediate drive electrodes
`may be eliminated, resulting in an improved layout effi
`ciency as well as a reduction in space requirements.
`FIG. 3 illustrates an interdigitated drive electrode pattern
`300 with triangularly interpolated regions for a touchscreen
`according to an example embodiment. Pattern 300 includes
`a drive electrode 310 running in a first direction. Drive
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`electrode 310 is driven by a drive line X (not shown) and
`includes triangular projections indicated at 315. An adjacent
`electrode 330 includes triangular projections indicated at
`335 that are interdigitated with triangular projections 315,
`and are separated by a gap 237. The area of interdigitation
`of drive electrodes 310 and 330 provide an interpolated or
`intermediate drive section as represented by broken line 345
`and the description of the signal at the interpolated drive
`section: (X+X)/2 signifying that the interpolated drive
`section is effectively driven with one half the signal from
`each of the adjacent drive lines when such drive electrodes
`are driven.
`Layout 300 provides a near one to one relationship
`between drive sections and interpolated drive sections. In
`one embodiment, the drive sections and interpolated drive
`sections run in the first direction, and are substantially the
`same width. The gap 237 in one embodiment, is narrow
`enough to provide Substantial coverage by the conductive
`material of the electrodes, but wide enough to provide
`consistent electrical isolation between the adjacent elec
`trodes. In some embodiments, an electrode layout may
`contain more than one interdigitated electrode shape, Such as
`a combination of stepped, triangular, saw toothed, or other
`shapes having one or more sloped sides.
`FIG. 4 is an illustration of an alternative interdigitated
`drive electrode layout 400. In one embodiment, the drive
`electrodes are formed with interdigitated triangular areas of
`the drive electrodes to create interpolated drive sections. The
`triangular areas may be used to create a near one to one
`relationship between drive sections and interpolated drive
`sections. In further embodiments, the triangular projections
`may extend farther than the width of a single drive section,
`such that two or more interpolated drive sections may be
`obtained between each driven section. The triangular por
`tions in one embodiment may extend an integer number of
`widths of a drive section to provide the same integer number
`of interpolated drive sections between each drive section. As
`one possible example, FIG. 4 shows three latitudinal lines of
`interpolation which may be employed to stretch the elec
`trode spacing between the primary drive sections. The
`mixture of fields from the primary drive sections is shown in
`the 6 equations of the drawing.
`FIG. 5 is an illustration of an interdigitated drive electrode
`pattern 500 with multiple stepped interpolation for a touch
`screen according to an example embodiment. Pattern 500
`includes a drive electrode 510 running in a first direction.
`Drive electrode 510 is driven by a drive line X, not shown,
`and includes multiple stepped projections indicated at 515,
`520, and 530. An adjacent electrode 535 includes multiple
`stepped projections indicated at 540, 545, and 550 that are
`interdigitated with the stepped projections of the first drive
`electrode 510. The non-interdigitated electrode sections or
`Zones labeled Xo and X provide primary field emission,
`while the interdigitated sections labeled (3X+X)/4, (X+
`X)/2, and (X+3X)/4 provide three intermediate field
`mixtures in order to provide interpolation between Zones X
`and X, according to the ratio of Surface areas of X and X
`in these respective Zones. In this example, the touch panel
`can be driven by approximately 4 the number of drive lines
`that would otherwise be required without the use of inter
`digitation. Pattern 500 provides an almost one to three
`relationship between drive sections and interpolated drive
`sections. In one embodiment, the drive sections and inter
`polated drive sections run in the first direction, and are
`substantially the same width. The distance between the
`projections in one embodiment, is Small enough to provide
`substantial coverage by the conductive material of the
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`Petitioner STMICROELECTRONICS, INC.,
`Ex. 1009, IPR2021-01161 Page 17 of 21
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`electrodes, and large enough to provide consistent electrical
`isolation between the adjacent electrodes.
`FIG. 6 is an example 2-layer electrode pattern 600. In one
`embodiment, drive electrodes are on an underlying layer and
`receive electrodes are on an upper layer as shown. The drive
`electrodes may be formed over a display, such as an LED
`(light emitting diode), LCD (liquid crystal display), OLED
`(organic LED), CRT (cathode ray tope), or other type of
`display device. One drive electrode is identified at 610.
`Between each set of adjacent drive sections are interdigi
`tated drive sections, referred to as interpolated drive sec
`tions. One such interdigitated section is indicated at 620. It
`is driven by the corresponding drive lines of adjacent drive
`sections.
`Also visible in FIG. 6 are a plurality of sense electrodes,
`also referred to as Y electrodes. The Y electrodes in one
`embodiment are separated from the X drive electrodes by a
`dielectric layer and run generally in a second direction. An
`example Y electrode includes a spine as indicated at 625
`having crossbars extending from both sides of the spine at
`630 and 635. The spines 625 generally run transverse to the
`drive electrodes, crossing both drive sections and interpo
`lated drive sections. The crossbars generally extend from the
`spines 625 in the same direction as the drive electrodes. In
`one embodiment, the crossbars of adjacent spines overlap
`for about 50% of the distance between the spines. Thus, each
`crossbar extends about 75% of the distance between spines.
`Additional sense electrodes and drive electrodes may be
`included in layout 600 as indicated by the dots. In further
`embodiments, the spines do not have crossbars.
`FIG. 6 also includes a blown up portion of the electrode
`layout at 640. The blown up portion shows that the drive
`electrodes are separated from each other by a gap Such that
`they are not in direct electrical contact with each other.
`Further, the crossbars are also separated by a gap.
`FIG. 7 is an illustration of an interdigitated drive electrode
`layout 700 with multiple stepped interpolation, and sense
`electrodes 705 with crossbars 706. In one embodiment, drive
`electrodes 710, 711, 712, 713, and 714 are illustrated.
`Additional sense electrodes and drive electrodes may be
`included in layout 700 as indicated by the dots. Note that the
`reference numbers are meant to identify the drive electrodes,
`not the crossbars of corresponding sense electrodes. The
`drive electrodes may be driven by corresponding drive lines.
`Three interpolated drive sections may be formed between
`the drive sections using three steps to provide an interdigi
`tated area such as indicated at 720,721, and 722. Layout 700
`thus provides many interpolated drive sections with only a
`few drive lines.
`FIG. 7 also includes a blown up portion of the electrode
`layout at 740. The blown up portion shows that the drive
`electrodes are separated from each other by a gap Such that
`they are not in direct electrical contact with each other.
`Further, the crossbars are also separated by a gap.
`FIG. 8 illustrates an alternative interdigitated drive elec
`trode layout 800 with interpolated sections for a touchscreen
`according to an example embodiment. In this embodiment,
`filled drive electrodes, such as drive electrode 810 has
`repeating saw tooth projections 815 that interdigitate with
`corresponding saw tooth projections 820 of an adjacent
`drive electrode 825. The interdigitated saw tooth projections
`815 and 820 form an interpolated section 823 that is effec
`tively driven via drive electrodes 810 and 825. In one
`embodiment, the saw tooth projections are in the shape of an
`isosceles triangle. Further triangular shapes may be used in
`further embodiments, to obtain an interpolated section that
`includes electrode projections equally from each drive elec
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`trode. A near one to one correspondence between drive
`sections and interpolated sections is obtained in this manner.
`In further embodiments, the triangular projections may
`extend longer than the width of a single drive electrode, such
`that two or more interpolated sections may be obtained
`between each driven electrode.
`FIG. 9 illustrates a receive electrode pattern 900 for the
`alternative interdigitated drive electrode pattern of FIG. 8.
`Several receive electrodes labeled Yo-Ys are illustrated and
`have spines 915 and crossbars 920 in one embodiment.
`FIG. 10 illustrates the electrode pattern of FIG. 8 with
`interpolation, along with sense electrodes generally at 1000.
`In addition to the drive electrodes with interdigitated trian
`gular projections to form interpolated drive electrodes
`between drive electrodes, receive electrodes Yo-Ys having
`spines 915 and crossbars 920 are aligned with the drive
`electrodes in two separate layers and are separated by a
`dielectric. The crossbars 920, one of which is identified by
`a reference number, align with and run in the same general
`direction as both the drive electrode and interpolated drive
`electrodes.
`In the embodiment shown, six drive electrodes X-Xs and
`six sense electrodes Yo-Ys may be coupled to a controller
`(not shown). An additional five interpolated drive electrode
`sections may be derived from the interdigitation of the
`projections of the drive electrodes. In one embodiment, each
`intersection of the Y electrode spines with the drive elec
`trodes and interpolated drive electrode sections forms a node
`from which touch information may be derived. The cross
`bars of the spines as well as the interpolated drive electrode
`sections both contribute to sensing touch, facilitating an
`interpolation of signals via adjacent nodes.
`FIG. 11 is an illustration of an alternative drive electrode
`layout 1100 for a portion of a touchscreen having interpo
`lated fine line drive electrodes, for example made of metal
`using line widths narrow enough and sparse enough so as not
`to be easily visible when placed over a display screen. In one
`embodiment, layout 1100 has primary boxed-in drive sec
`tions indicated at 1106, 1108 and 1110. Drive section 1110
`includes a primary drive line 1111 running through the
`center of the boxed-in drive section, and adjacent box lines
`1113 and 1115, along with a plurality of intersecting cross
`lines 1120, three of which are identified by reference num
`ber. In one embodiment, the lines bounded by box lines 1113
`and 1115 are all electrically coupled to each other, forming
`a box like drive electrode whose length spans one dimension
`of the touch panel and whose width spans a dimension
`similar to that of a solid electrode shape such as shown as Xo,
`in FIG. 2. The box geometry shown in section 1110 provides
`for multiple electrical pathways which act to improve manu
`facturing yields which could otherwise be negatively
`impacted due to breaks or fractures in the fine lines caused
`by process imperfections and material handling. The three
`longitudinal pathways formed by 1115, 1111, and 1113 act to
`shunt current flow around single-point or even two-point
`failures in most cases, thereby preventing Small defects from
`causing dead regions in the touch panel's response.
`The fine lines in one embodiment of FIG. 11 have a width
`of 10 um or less, along with an average density of 5% or less
`over the display area. The density may be higher or lower in
`further embodiments. The line widths and density may be
`selected such that a display beneath the electrodes remains
`substantially visible to a user of the touchscreen without
`observable optical interference. In one embodiment, the
`cross lines 1120 may be at a diagonal from the lines 1111,
`1113 and 1115 to reduce optical moiré effects. In a further
`embodiment, the spine and box lines 1111, 1113 and 1115
`
`Petitioner STMICROELECTRONICS, INC.,
`Ex. 1009, IPR2021-01161 Page 18 of 21
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`may also be formed of curves or Zig-Zag line segments to
`further reduce optical interference with the display pixels
`under the electrode array. All comments related to section
`1110 as noted above apply equally to other similar sections
`for example 1106 and 1108.
`Interpolated sections 1130, 1132 reside between the pri
`mary drive sections 1106, 1108 and 1110. These interpolated
`sections include box line replicators as indicated at 1135 and
`cross lines 1140 that alternately couple to box lines 1115 and
`a box line 1142 of neighboring primary drive section 1108.
`Only two of the box line replicators 1135 and cross lines
`1140 are identified by reference number. The purpose of the
`box line replicators