US009372580B2
`
`(12) United States Patent
`Simmons et al.
`
`(10) Patent No.:
`(45) Date of Patent:
`
`US 9,372,580 B2
`Jun. 21, 2016
`
`(54) ENHANCED TOUCH DETECTION METHODS
`
`(75) Inventors: it,John E. start
`(GB); Darren Golbourn, Southampton
`(GB); Daniel Pickett, Southampton
`(GB); Andrew Hersee, Southampton
`(GB)
`
`(*) Notice:
`
`(73) Assignee: Atmel Corporation, San Jose, CA (US)
`-
`Subject to any disclaimer, the term of this
`patent is extended or adjusted under 35
`U.S.C. 154(b) by 425 days.
`
`8,031,094 B2 10/2011 Hotelling
`8,031,174 B2 10/2011 Hamblin
`8,040.326 B2 10/2011 Hotelling
`8,049,732 B2 11/2011 Hotelling
`8,179,381 B2
`5/2012 Frey
`8.462,135 B1* 6/2013 Xiao et al. .................... 345,174
`8,482.544 B2 * 7/2013 Land et al. .....
`... 345,174
`8,692,795 B1 * 4/2014 Kremin et al. .
`... 345,174
`8,773,146 B1* 7/2014 Hills et al. ...
`... 324f658
`8,810,544 B2 * 8/2014 Liu et al. ....................... 345,174
`2009/0315854 A1 12, 2009 Matt
`2010/0001966 A1
`1/2010 Lii et al. ........................ 345,173
`2012/00498.69 A1
`3/2012 Kremlin et al. .
`... 324f679
`2012/0206407 A1* 8/2012 Taylor et al. .................. 345,174
`(Continued)
`
`(21) Appl. No.: 13/332,945
`
`(22) Filed:
`
`Dec. 21, 2011
`
`FOREIGN PATENT DOCUMENTS
`
`WO WO 2012/1292.47
`
`9, 2012
`
`(65)
`
`Prior Publication Data
`
`OTHER PUBLICATIONS
`
`US 2013/O162583 A1
`
`Jun. 27, 2013
`
`(2006.01)
`(2006.01)
`(2006.01)
`
`(51) Int. Cl.
`G06F 3/045
`G06F 3/044
`G06F 3/04
`(52) U.S. Cl.
`CPC .............. G06F 3/044 (2013.01); G06F 3/04 16
`(2013.01); G06F 3/0418 (2013.01); G06F
`2203/04 104 (2013.01); G06F 2203/041 12
`(2013.01)
`
`(58) Field of Classification Search
`CPC ..... G06F 3/044: G06F 3/0416: G06F 3/0418;
`G06F 2203/04104; G06F 2203/04112
`USPC .......................................................... 34.5/174
`See application file for complete search history.
`
`(56)
`
`References Cited
`U.S. PATENT DOCUMENTS
`
`7,663,607 B2 *
`7,875,814 B2
`7,920,129 B2
`
`2/2010 Hotelling et al. ............. 345,173
`1/2011 Chen
`4/2011 Hotelling
`
`
`
`U.S. Appl. No. 61/454,936, filed Mar. 21, 2011, Myers.
`(Continued)
`
`Primary Examiner — Aneeta Yodichkas
`Assistant Examiner — Joseph Fox
`(74) Attorney, Agent, or Firm — Baker Botts L.L.P.
`(57)
`ABSTRACT
`In one embodiment, a method includes sending a first set of
`signals to a first set of lines of a touch sensor. The method also
`includes receiving a second set of signals on a second set of
`lines of the touch sensor in response to sending the first set of
`signals. The second set of lines are capacitively coupled to the
`first set of lines. The method includes sending a third set of
`signals and receiving a fourth set of signals. The fourth set of
`signals is capacitively generated based on the third set of
`signals. The method also includes determining a fifth set of
`signals by compensating the second set of signals based on
`the fourth set of signals and determining whether a touch
`occurred based on the fifth set of signals.
`12 Claims, 3 Drawing Sheets
`
`TOUCH 1
`
`
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`DELL EXHIBIT 1001 PAGE 1
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`DELL EXHIBIT 1001 PAGE 1
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`

`

`US 9,372.580 B2
`Page 2
`
`(56)
`
`References Cited
`
`OTHER PUBLICATIONS
`
`U.S. PATENT DOCUMENTS
`
`2012fO242.588 A1
`2012fO242592 A1
`2012fO243151 A1
`2012fO243719 A1
`
`9/2012 Myers
`9/2012 Rothkopf
`9/2012 Lynch
`9, 2012 Franklin
`
`U.S. Appl. No. 61/454,950, filed Mar. 21, 2011, Lynch.
`U.S. Appl. No. 61/454,894, filed Mar. 21, 2011, Rothkopf.
`
`* cited by examiner
`
`DELL EXHIBIT 1001 PAGE 2
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`DELL EXHIBIT 1001 PAGE 2
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`

`

`U.S. Patent
`
`Jun. 21, 2016
`
`Sheet 1 of 3
`
`US 9,372.580 B2
`
`100-
`
`8 *-* CONNECTION
`
`s
`
`CONROER
`
`W X
`
`FIG. A
`
`
`
`DELL EXHIBIT 1001 PAGE 3
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`DELL EXHIBIT 1001 PAGE 3
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`

`

`U.S. Patent
`
`Jun. 21, 2016
`
`Sheet 2 of 3
`
`US 9,372.580 B2
`
`200
`
`210
`
`220
`
`230
`
`240
`
`250
`
`260
`
`START
`
`SEND SIGNALS ON
`FIRST SET OF LINES
`
`MEASURE SIGNALS ON
`SECOND SET OF LINES
`
`SEND SIGNALS ON
`FIRST SET OF LINES
`
`MEASURE SIGNALS ON
`FIRST SET OF LINES
`
`SEND SIGNALS ON
`SECOND SET OF LINES
`
`MEASURE SIGNALS ON
`SECOND SET OF LINES
`
`255
`
`COMPENSATION
`NEEDED?
`
`COMPENSATE USING
`MEASUREMENTS
`
`
`
`TOUCHES
`DETECTED
`
`NO
`
`
`
`
`
`
`
`
`
`280
`
`DETERMINE COORDINATES
`
`DELL EXHIBIT 1001 PAGE 4
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`DELL EXHIBIT 1001 PAGE 4
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`

`

`U.S. Patent
`
`Jun. 21, 2016
`
`Sheet 3 of 3
`
`US 9,372.580 B2
`
`START
`
`SEND SIGNALS WHILE
`FIRST SET OF LINES
`ARE GROUNDED
`
`MEASURE SIGNALS ON
`SECOND SET OF LINES
`
`SEND SIGNALS WHILE
`FIRST SET OF LINES
`ARE FLOATING
`
`MEASURESIGNALS ON
`SECOND SET OF LINES
`
`DO
`MEASUREMENTS
`DIFFER
`
`340
`
`COMPENSATE
`
`300
`
`310
`
`
`
`320
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`330
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`
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`350
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`
`
`
`
`
`
`TOUCHES
`DETECTED?
`
`
`
`
`
`360
`
`370
`
`DETERMINE COORDINATES
`
`SEND SIGNALS ON
`FIRST SET OF LINES
`
`MEASURE SIGNALS ON
`SECOND SET OF LINES
`
`SEND MODIFIED SIGNALS
`TO FIRST SET OF LINES
`
`MEASURE SIGNALS ON
`SECOND SET OF LINES
`
`
`
`
`
`COMPENSATE
`
`TOUCHES
`DETECTED?
`
`NO
`
`
`
`400
`
`410
`
`420
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`430
`
`
`
`450
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`
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`470
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`DELL EXHIBIT 1001 PAGE 5
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`DELL EXHIBIT 1001 PAGE 5
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`

`

`1.
`ENHANCED TOUCH DETECTION METHODS
`
`US 9,372,580 B2
`
`BACKGROUND
`
`A touch sensor may detect the presence and location of a
`touch or the proximity of an object (such as a user's finger or
`a stylus) within a touch-sensitive area of the touch sensor
`overlaid on a display Screen, for example. In a touch sensitive
`display application, the touch position sensor may enable a
`user to interact directly with what is displayed on the screen,
`rather than indirectly with a mouse or touch pad. A touch
`sensor may be attached to or provided as part of a desktop
`computer, laptop computer, tablet computer, personal digital
`assistant (PDA). Smartphone, satellite navigation device, por
`table media player, portable game console, kiosk computer,
`point-of-sale device, or other suitable device. A control panel
`on a household or other appliance may includea touch sensor.
`There are a number of different types of touch position
`sensors, such as (for example) resistive touchscreens, Surface
`acoustic wave touch screens, and capacitive touch screens.
`Herein, reference to a touch sensor may encompass a touch
`screen, and vice versa, where appropriate. When an object
`touches or comes within proximity of the surface of the
`capacitive touch screen, a change in capacitance may occur
`within the touch screen at the location of the touch or prox
`imity. A touch-sensor controller may process the change in
`capacitance to determine its position on the touch screen.
`Poor coupling between a user of a device and the device
`itself may lead to inaccurate measurements and cause actual
`touches to be missed or inaccurately reported. Effects caused
`by poor coupling between the user and the device may be
`referred to as free space effects. One such example is retrans
`mission of drive signal from a drive line on which one touch
`is present to a sense line on which another touch is present (or
`when the same touch is present on multiple sense lines and/or
`multiple drive lines, e.g., when the device is touched by a
`large finger, a palm, or a cheek) when the user is touching two
`or more nodes simultaneously resulting in an unexpected
`amount of drive signal coupled to (and measured on) the
`senseline. The amount may be unexpected when compared to
`the amount of drive signal coupled to the senseline when only
`one node is being touched. This may affect the accuracy of
`touch sensing devices.
`
`5
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`10
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`15
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`25
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`30
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`35
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`40
`
`BRIEF DESCRIPTION OF THE DRAWINGS
`
`Reference is now made to the following description taken
`in conjunction with the accompanying drawings, wherein like
`reference numbers represent like parts and which:
`FIG. 1A illustrates an example touch device that includes
`an example touch sensor with an example controller,
`FIG. 1B illustrates use of a touch sensor of FIG. 1A that
`introduces retransmission effects;
`FIG. 1C illustrates multiple ground paths when using the
`touch device of FIG. 1A:
`FIG. 2 illustrates an example method for detecting touch
`input by comparing the effect of transmitted signals between
`lines of a touch sensor oriented in the same direction;
`FIG. 3 illustrates an example method for detecting touch
`input on a device that includes changing one or more lines of
`a touch sensor to be grounded or floating; and
`FIG. 4 illustrates an example method for detecting touch
`input on a device that includes sending different types of
`signals on one or more lines of a touch sensor.
`
`DESCRIPTION OF EXAMPLE EMBODIMENTS
`
`FIG. 1A illustrates an example touch device 100 that
`includes an example touch sensor 10 with an example touch
`
`45
`
`50
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`55
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`60
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`65
`
`2
`sensor controller 12. Touch sensor 10 and touch-sensor con
`troller 12 may detect the presence and location of a touch or
`the proximity of an object within a touch-sensitive area of
`touch sensor 10. Touch-sensor controller 12 may be config
`ured to accurately detect touches by sending multiple types of
`signals to touch sensor 10 and analyzing signals sent by touch
`sensor 10 in response. This may be advantageous in that
`touch-sensor controller 12 may be able to detect accurate
`touches even in the presence of free space effects Such as
`retransmission and various grounding environments (dis
`cussed further below with respect to FIGS. 1B and 1C).
`Herein, reference to a touch sensor may encompass both
`the touch sensor and its touch-sensor controller, where appro
`priate. Similarly, reference to a touch-sensor controller may
`encompass both the touch-sensor controller and its touch
`sensor, where appropriate. Touch sensor 10 may include one
`or more touch-sensitive areas, where appropriate. Touchsen
`Sor 10 may include an array of electrodes disposed on one or
`more Substrates, which may be made of a dielectric material.
`Herein, reference to a touch sensor may encompass both the
`electrodes of the touch sensor and the substrate(s) that they
`are disposed on, where appropriate. Alternatively, where
`appropriate, reference to a touch sensor may encompass the
`electrodes of the touch sensor, but not the substrate(s) that
`they are disposed on.
`An electrode may be an area of conductive material form
`ing a shape, such as for example a disc, square, rectangle, thin
`line, other suitable shape, or suitable combination of these.
`One or more cuts in one or more layers of conductive material
`may (at least in part) create the shape of an electrode, and the
`area of the shape may (at least in part) be bounded by those
`cuts. In particular embodiments, the conductive material of an
`electrode may occupy approximately 100% of the area of its
`shape. As an example and not by way of limitation, an elec
`trode may be made of indium tin oxide (ITO) and the ITO of
`the electrode may occupy approximately 100% of the area of
`its shape (sometimes referred to as 100% fill), where appro
`priate. In particular embodiments, the conductive material of
`an electrode may occupy substantially less than 100% of the
`area of its shape. As an example and not by way of limitation,
`an electrode may be made of fine lines of metal or other
`conductive material (FLM), such as for example copper, sil
`ver, or a copper- or silver-based material, and the fine lines of
`conductive material may occupy approximately 5% of the
`area of its shape in a hatched, mesh, or other Suitable pattern.
`Herein, references to FLM encompasses such material, where
`appropriate. Although this disclosure describes or illustrates
`particular electrodes made of particular conductive material
`forming particular shapes with particular fills having particu
`lar patterns, this disclosure contemplates any suitable elec
`trodes made of any Suitable conductive material forming any
`Suitable shapes with any Suitable fill percentages having any
`suitable patterns. Where appropriate, the shapes of the elec
`trodes (or other elements) of a touch sensor may constitute in
`whole or in part one or more macro-features of the touch
`sensor. One or more characteristics of the implementation of
`those shapes (such as, for example, the conductive materials,
`fills, or patterns within the shapes) may constitute in whole or
`in part one or more micro-features of the touch sensor. One or
`more macro-features of a touch sensor may determine one or
`more characteristics of its functionality, and one or more
`micro-features of the touch sensor may determine one or
`more optical features of the touch sensor, Such as transmit
`tance, refraction, or reflection.
`A mechanical stack may contain the Substrate (or multiple
`Substrates) and the conductive material forming the elec
`trodes of touch sensor 10. As an example and not by way of
`
`DELL EXHIBIT 1001 PAGE 6
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`DELL EXHIBIT 1001 PAGE 6
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`

`

`US 9,372,580 B2
`
`10
`
`15
`
`3
`limitation, the mechanical stack may include a first layer of
`optically clear adhesive (OCA) beneath a cover panel. The
`cover panel may be clear and made of a resilient material
`Suitable for repeated touching, Such as for example glass,
`polycarbonate, or poly(methyl methacrylate) (PMMA). This
`disclosure contemplates any Suitable cover panel made of any
`suitable material. The first layer of OCA may be disposed
`between the cover panel and the substrate with the conductive
`material forming the electrodes. The mechanical stack may
`also include a second layer of OCA and a dielectric layer
`(which may be made of PET or another suitable material,
`similar to the substrate with the conductive material forming
`the electrodes). As an alternative, where appropriate, a thin
`coating of a dielectric material may be applied instead of the
`second layer of OCA and the dielectric layer. The second
`layer of OCA may be disposed between the substrate with the
`conductive material making up the electrodes and the dielec
`tric layer, and the dielectric layer may be disposed between
`the second layer of OCA and an air gap to a display of a device
`including touch sensor 10 and touch-sensor controller 12. As
`an example only and not by way of limitation, the cover panel
`may have a thickness of approximately 1 mm; the first layer of
`OCA may have a thickness of approximately 0.05 mm; the
`substrate with the conductive material forming the electrodes
`may have a thickness of approximately 0.05 mm; the second
`layer of OCA may have a thickness of approximately 0.05
`mm, and the dielectric layer may have a thickness of approxi
`mately 0.05 mm. Although this disclosure describes a par
`ticular mechanical stack with a particular number of particu
`lar layers made of particular materials and having particular
`thicknesses, this disclosure contemplates any Suitable
`mechanical stack with any suitable number of any suitable
`layers made of any Suitable materials and having any suitable
`thicknesses. As an example and not by way of limitation, in
`particular embodiments, a layer of adhesive or dielectric may
`replace the dielectric layer, second layer of OCA, and air gap
`described above, with there being no air gap to the display.
`One or more portions of the substrate of touch sensor 10
`may be made of polyethylene terephthalate (PET) or another
`Suitable material. This disclosure contemplates any suitable
`substrate with any suitable portions made of any suitable
`material. In particular embodiments, the electrodes in touch
`sensor 10 may be made of ITO in whole or in part. In particu
`lar embodiments, the electrodes in touch sensor 10 may be
`made offine lines of metal or other conductive material. As an
`45
`example and not by way of limitation, one or more portions of
`the conductive material may be copper or copper-based and
`have a thickness of approximately 5um or less and a width of
`approximately 10 um or less. As another example, one or
`more portions of the conductive material may be silver or
`silver-based and similarly have a thickness of approximately
`5um or less and a width of approximately 10um or less. This
`disclosure contemplates any suitable electrodes made of any
`suitable material.
`Touch sensor 10 may implement a capacitive form of touch
`sensing. In a mutual-capacitance implementation, touchsen
`Sor 10 may include one or more arrays of electrodes forming
`an array of capacitive nodes. An electrode aligned in a first
`axis (e.g., the X-axis) and an electrode aligned in a second axis
`(e.g., the y-axis) may form a capacitive node. The electrodes
`forming the capacitive node may come near each other, but
`not make electrical contact with each other. Instead, the elec
`trodes may be capacitively coupled to each other across a
`space between them. A pulsed or alternating Voltage applied
`to one electrode (by touch-sensor controller 12) may induce a
`charge on the other electrode, and the amount of charge
`induced may be susceptible to external influence (such as a
`
`55
`
`4
`touch or the proximity of an object). When an object touches
`or comes within proximity of the capacitive node, a change in
`capacitance may occur at the capacitive node and touch
`sensor controller 12 may measure the change in capacitance.
`By measuring changes in capacitance throughout the array,
`touch-sensor controller 12 may determine the position of the
`touch or proximity within the touch-sensitive area(s) of touch
`sensor 10.
`In a self-capacitance implementation, touch sensor 10 may
`include an array of electrodes that may each form a capacitive
`node. When an object touches or comes within proximity of
`the capacitive node, a change in self-capacitance may occurat
`the capacitive node and touch-sensor controller 12 may mea
`Sure the change incapacitance, for example, as a change in the
`amount of charge needed to raise the Voltage at the capacitive
`node by a pre-determined amount. As with a mutual-capaci
`tance implementation, by measuring changes in capacitance
`throughout the array, touch-sensor controller 12 may deter
`mine the position of the touch or proximity within the touch
`sensitive area(s) of touch sensor 10. This disclosure contem
`plates any suitable form of capacitive touch sensing, where
`appropriate.
`In particular embodiments, one or more electrodes may
`together form one or more lines running horizontally, Verti
`cally, and/or in any suitable orientation. In particular embodi
`ments, some lines may run Substantially perpendicular to
`other lines. Herein, reference to a line may encompass one or
`more electrodes making up the line, and vice versa, where
`appropriate.
`Touch sensor 10 may have electrodes disposed in a pattern
`on one side of a single Substrate. In such a configuration, a
`pair of electrodes capacitively coupled to each other across a
`space between them may form a capacitive node. For a self
`capacitance implementation, electrodes may be disposed in a
`pattern on a single Substrate. In addition or as an alternative to
`having electrodes disposed in a pattern on one side of a single
`Substrate, touch sensor 10 may have some electrodes (e.g.,
`electrodes aligned in the X-axis) disposed in a pattern on one
`side of a Substrate and other electrodes (e.g., electrodes
`aligned in the y-axis) disposed in a pattern on another side of
`the substrate. Moreover, touch sensor 10 may have some
`electrodes (e.g., electrodes aligned in the X-axis) disposed in
`a pattern on one side of one substrate and other electrodes
`(e.g., electrodes aligned in the y-axis) disposed in a pattern on
`one side of another Substrate. In Such configurations, an inter
`section of electrodes may form a capacitive node. Such an
`intersection may be a location where the electrodes “cross' or
`come nearest each other in their respective planes. The elec
`trodes do not make electrical contact with each other in
`stead they are capacitively coupled to each other across a
`dielectric at the intersection. Although this disclosure
`describes particular configurations of particular electrodes
`forming particular nodes, this disclosure contemplates any
`Suitable configuration of any suitable electrodes forming any
`Suitable nodes. Moreover, this disclosure contemplates any
`Suitable electrodes disposed on any Suitable number of any
`Suitable Substrates in any Suitable patterns.
`As described above, a change in capacitance at a capacitive
`node of touch sensor 10 may indicate a touch or proximity
`input at the position of the capacitive node. Touch-sensor
`controller 12 may detect and process the change in capaci
`tance to determine the presence and location of the touch or
`proximity input. Touch-sensor controller 12 may then com
`municate information about the touch or proximity input to
`one or more other components (such one or more central
`processing units (CPUs)) of a device that includes touch
`sensor 10 and touch-sensor controller 12, which may respond
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`DELL EXHIBIT 1001 PAGE 7
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`US 9,372,580 B2
`
`5
`to the touch or proximity input by initiating a function of the
`device (or an application running on the device). Although
`this disclosure describes a particular touch-sensor controller
`having particular functionality with respect to a particular
`device and a particular touch sensor, this disclosure contem
`plates any Suitable touch-sensor controller having any Suit
`able functionality with respect to any suitable device and any
`Suitable touch sensor.
`Touch-sensor controller 12 may be one or more integrated
`circuits (ICs). Such as for example general-purpose micropro
`cessors, microcontrollers, programmable logic devices or
`arrays, application-specific ICs (ASICs). In particular
`embodiments, touch-sensor controller 12 comprises analog
`circuitry, digital logic, and digital non-volatile memory. In
`particular embodiments, touch-sensor controller 12 is dis
`posed on a flexible printed circuit (FPC) bonded to the sub
`strate of touch sensor 10, as described below. The FPC may be
`active or passive, where appropriate. In particular embodi
`ments, multiple touch-sensor controllers 12 are disposed on
`the FPC. Touch-sensor controller 12 may include a processor
`unit, a drive unit, a sense unit, and a storage unit. The drive
`unit may supply drive signals to electrodes of touch sensor 10.
`The sense unit may sense charge at the capacitive nodes of
`touch sensor 10 and provide measurement signals to the pro
`cessor unit representing capacitances at the capacitive nodes.
`The processor unit may control the Supply of drive signals to
`the electrodes by the drive unit and process measurement
`signals from the sense unit to detect and process the presence
`and location of a touch or proximity input within the touch
`sensitive area(s) of touch sensor 10. The processor unit may
`also track changes in the position of a touch or proximity
`input within the touch-sensitive area(s) of touch sensor 10. In
`Some embodiments, touch-sensor controller 12 may be con
`figured to drive signals to and receive signals from all elec
`trodes (whether they are considered “drive' or “sense' elec
`trodes) of touch sensor 10. Touch-sensor controller 12 may be
`configured to cause any electrode of touch sensor 10 to be
`grounded or to be floating with respect to device 100. The
`storage unit may store programming for execution by the
`processor unit, including programming for controlling the
`drive unit to Supply drive signals to the electrodes, program
`ming for processing measurement signals from the sense unit,
`and other Suitable programming, where appropriate.
`Although this disclosure describes a particular touch-sensor
`controller having a particular implementation with particular
`components, this disclosure contemplates any Suitable touch
`sensor controller having any suitable implementation with
`any Suitable components.
`Tracks 14 of conductive material disposed on the substrate
`of touch sensor 10 may couple the electrodes of touch sensor
`10 to connection pads 16, also disposed on the substrate of
`touch sensor 10. As described below, connection pads 16
`facilitate coupling of tracks 14 to touch-sensor controller 12.
`Tracks 14 may extend into or around (e.g. at the edges of) the
`touch-sensitive area(s) of touch sensor 10. Particular tracks
`14 may provide drive connections for coupling touch-sensor
`controller 12 to electrodes of touch sensor 10, through which
`the drive unit of touch-sensor controller 12 may supply drive
`signals to the electrodes. Other tracks 14 may provide sense
`connections for coupling touch-sensor controller 12 to elec
`trodes of touch sensor 10, through which the sense unit of
`touch-sensor controller 12 may sense charge at the capacitive
`nodes of touch sensor 10. Tracks 14 may be made offine lines
`of metal or other conductive material. As an example and not
`by way of limitation, the conductive material of tracks 14 may
`be copper or copper-based and have a width of approximately
`100 um or less. As another example, the conductive material
`
`40
`
`45
`
`6
`of tracks 14 may be silver or silver-based and have a width of
`approximately 100 um or less. In particular embodiments,
`tracks 14 may be made of ITO in whole or in part in addition
`or as an alternative to fine lines of metal or other conductive
`material. Although this disclosure describes particular tracks
`made of particular materials with particular widths, this dis
`closure contemplates any suitable tracks made of any Suitable
`materials with any suitable widths. In addition to tracks 14,
`touch sensor 10 may include one or more ground lines termi
`nating at a ground connector (which may be a connection pad
`16) at an edge of the substrate of touch sensor 10 (similar to
`tracks 14).
`Connection pads 16 may be located along one or more
`edges of the Substrate, outside the touch-sensitive area(s) of
`touch sensor 10. As described above, touch-sensor controller
`12 may be on an FPC. Connection pads 16 may be made of the
`same material as tracks 14 and may be bonded to the FPC
`using an anisotropic conductive film (ACF). Connection 18
`may include conductive lines on the FPC coupling touch
`sensor controller 12 to connection pads 16, in turn coupling
`touch-sensor controller 12 to tracks 14 and to the electrodes of
`touch sensor 10. In another embodiment, connection pads 16
`may be connected to an electro-mechanical connector (Such
`as a Zero insertion force wire-to-board connector); in this
`embodiment, connection 18 may not need to include an FPC.
`This disclosure contemplates any suitable connection 18
`between touch-sensor controller 12 and touch sensor 10.
`FIG. 1B illustrates use of touch sensor 10 that introduces
`retransmission effects. Such effects may occur due to a touch
`on touch sensor 10 by one or more objects (e.g., a stylus
`and/or a human finger) that are weakly coupled to the ground
`of touch sensor 10. As discussed above, when touch-sensor
`controller 12 detects touches using mutual capacitance,
`touch-sensor controller 12 may sequentially send signals on
`lines in one axis (e.g., lines X1 and X4) and receive signals on
`lines in another axis (e.g., lines Y1 and Y5). Touch-sensor
`controller 12 may use the timing of the sequentially driven
`lines to determine coordinates of a touch. For example, when
`line X4 is driven, touch-sensor controller 12 may receive
`signals indicating a touch on line Y5. Because touch-sensor
`controller 12 knows when line X4 is driven, touch-sensor
`controller 12 may determine the coordinates of the touch
`sensed on line Y5 by examining the time when signals were
`received from line Y5. A retransmission effect may occur,
`though, as depicted in FIG. 1B. For example, a user may
`touch touch sensor 10 in two locations such that one finger is
`onlines X4 and Y5 and another finger onlines X1 and Y1. As
`another example, a touch by an object with a relatively large
`Surface area (e.g., the palm of a human hand) may cause a
`touch at multiple locations. A drive signal sent onlineX1 may
`be transmitted to line Y5 through the user's hand. This may
`result in line Y5 receiving more charge as a result of line X1
`being driven than would have otherwise occurred. If a touch
`was present at the intersection of lines X1 and Y5 as well
`(which is not depicted in FIG. 1B), touch-sensor controller 12
`may not detect Such a touch as a result of the extra charge line
`Y5 received through the user's hand while line X1 was driven.
`A drive signal may be sent online X4 at a different time then
`was sent on line X1. Charge may be transferred to line Y1
`through the user's hand as a result of line X4 being driven.
`This may result in line Y1 receiving more charge as a result of
`line X4 being driven than would have otherwise occurred. If
`a touch was present at the intersection of lines X4 and Y1 as
`well (which is not depicted in FIG. 1B), touch-sensor con
`troller 12 may not detect such a touch as a result of the extra
`charge line Y1 received through the user's hand while lineX4
`was driven. To prevent problems that occur with retransmis
`
`10
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`15
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`25
`
`30
`
`35
`
`50
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`55
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`60
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`65
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`DELL EXHIBIT 1001 PAGE 8
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`DELL EXHIBIT 1001 PAGE 8
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`

`

`US 9,372,580 B2
`
`10
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`15
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`7
`Sion, touch-sensor controller 12 may be configured to per
`form one or more of the techniques discussed below with
`respect to FIGS. 2-4.
`FIG. 1C illustrates multiple ground paths when using
`device 100. Capacitance Cfb may be the capacitance between
`the user and Earth ground. Capacitance Cfd may be the
`capacitance between device 100 and Earth ground. Capaci
`tance Ct may be the capacitance between the user and device
`100. When device 100 is touched by a user that is weakly
`coupled to the ground of device 100, capacitances Cfb and/or
`Cfd may be relatively small. As a result, for example, the
`magnitude of changes detected by touch sensor 10 as a result
`of one or more touches may be substantially weakened lead
`ing to inaccurate touch detection. To prevent problems that
`occur with a user being poorly coupled to the electrical
`ground of device 100, touch-sensor controller 12 may be
`configured to perform one or more of the techniques dis
`cussed below with respect to FIGS. 2-4.
`FIGS. 2-4 illustrate example methods for touch detection
`techniques that may be employed by a controller (and/or one
`or more other Suitable components) such as touch-sensor
`controller 12 of FIG. 1. Some embodiments may repeat the
`steps of the methods of FIGS. 2-4, where appropriate. More
`over, although this disclosure describes and illustrates par
`ticular steps of the methods of FIGS. 2-4 as occurring in a
`particular order, this disclosure contemplates any suitable
`steps of the methods of FIGS. 2-4 occurring in any suitable
`order. Furthermore, although this disclosure describes and
`illustrates particular components, devices, or systems carry
`ing out particular steps of the methods of FIGS. 2-4, this
`disclosure contemplates any suitable combination of any Suit
`able components, devices, or systems carrying out any suit
`able steps of any of the methods of FIGS. 2-4.
`FIG. 2 illustrates an example method for detecting touch
`input by comparing the effect of transmitted signals between
`lines of a touch sensor oriented in the same direction. The
`method may start at step 200, where signals are transmitted to
`a first set of lines (e.g., lines oriented along the X-axis). For
`example, at this step a drive signal may be sent to a set of lines
`sequentially. Any suitable signal may be sent at this step. Such
`as a step function or a periodic signal. This step may be
`performed by a controller such as a touch-sensor controller 12
`of FIG.1. The signals and lines mentioned in this step may be
`implemented using the description above with respect to
`touch sensor 10 of FIG. 1.
`45
`At step 210, in Some embodiments, signals may be mea
`Sured on a second set of lines (e.g., lines oriented along the
`y-axis). As an example, lines discussed above with respect to
`touch sensor 10 of FIG.1 may provide signals to a controller
`(such as touch-sensor controller 12). The signals measured on
`the second set of lines may result from the signals sent at Step
`200 because, for example, the first set of lines may be capaci
`tively coupled to the second set of lines. The signals received
`at this step may indicate that at least one touch is present on
`the touch screen because the touch may affect or disturb the
`capacitive relationship between the first set of lines and the
`second set of lines.
`At step 220, in Some embodiments, signals may be sent on
`the first set of lines (e.g., lines oriented along the X-axis). In
`some embodiments, each of the first set of lines may be driven
`sequentially. The same or different signal patterns may be
`used at this step as in step 200. As an example, the controller
`may perform this step. In some embodiments, only