(19) United States
`(12) Patent Application Publication (10) Pub. No.: US 2006/0097991 A1
`(43) Pub. Date:
`May 11, 2006
`Hotelling et al.
`
`US 20060097991Al
`
`(54) MULTIPOINT TOUCHSCREEN
`
`(22) Filed:
`
`May 6, 2004
`
`(75) Inventors: Steve Hotelling, San Jose, CA (US);
`Joshua A. Strickon, San Jose, CA
`(US); Brian Q. Huppi, San Francisco,
`CA (US)
`
`Correspondence Address:
`WONG, CABELLO, LUTSCH, RUTHERFORD
`& BRUCCULERI,
`P.C.
`20333 SH 249
`SUITE 600
`HOUSTON, TX 77070 (US)
`
`(73) Assignee: Apple Computer, Inc.
`
`(21) Appl. No.:
`
`10/840,862
`
`Publication Classi?cation
`
`(51) Int. Cl.
`(2006.01)
`G09G 5/00
`(52) U.S. Cl. ............................................................ .. 345/173
`
`(57)
`
`ABSTRACT
`
`A touch panel having a transparent capacitive sensing
`medium con?gured to detect multiple touches or near
`touches that occur at the same time and at distinct locations
`in the plane of the touch panel and to produce distinct signals
`representative of the location of the touches on the plane of
`the touch panel for each of the multiple touches is disclosed.
`
`1
`
`Petitioner Samsung 1010
`
`

`

`Patent Application Publication May 11, 2006 Sheet 1 0f 14
`
`US 2006/0097991 A1
`
`FIG. 1A
`
`\%5
`
`FIG 18
`
`Row projectlon
`V slgnal
`
`Column projection
`signal
`
`[or
`
`2
`
`

`

`Patent Application Publication May 11, 2006 Sheet 2 0f 14
`
`US 2006/0097991 A1
`
`/
`
`s2
`
`S1
`
`38
`
`3
`
`

`

`Patent Application Publication May 11, 2006 Sheet 3 0f 14
`
`US 2006/0097991 A1
`
`38
`
`44
`
`44
`
`44
`
`42A
`
`44
`
`42A
`
`42
`
`FIG. 3
`
`4
`
`

`

`Patent Application Publication May 11, 2006 Sheet 4 0f 14
`
`US 2006/0097991 A1
`
`RECEIVE MULTIPLE J
`TOUCHES ON
`SURFACE OF TOUCH
`SCREEN
`
`I
`
`47
`RECOGNIZE EACH OF _/
`THE MULTIPLE
`TOUCHES
`
`48
`I
`REPORT TOUCH DATA j
`BASED ON MULTIPLE
`TOUCHES
`
`FIG. 4
`
`FIG. 5
`
`5
`
`

`

`Patent Application Publication May 11, 2006 Sheet 5 0f 14
`
`US 2006/0097991 A1
`
`104
`
`110
`
`116{
`
`110
`
`102
`
`100
`108 f
`
`110
`}116
`
`110
`110
`
`104
`112
`
`SERIAL DATA
`BUS
`
`106
`
`FIG. 6B
`
`6
`
`

`

`Patent Application Publication May 11, 2006 Sheet 6 0f 14
`
`US 2006/0097991 A1
`
`‘I’
`
`09K
`
`mm?
`
`
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`MQNF Mow?
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`7
`
`

`

`Patent Application Publication May 11, 2006 Sheet 7 0f 14
`
`US 2006/0097991 A1
`
`150
`
`156
`
`1588
`
`1528
`
`152A
`
`158A
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`154
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`190
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`170
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`192
`182
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`180
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`178
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`8
`
`

`

`Patent Application Publication May 11, 2006 Sheet 8 0f 14
`
`US 2006/0097991 A1
`
`f 200
`
`@@@@@@©
`
`206
`
`204
`
`206
`
`204
`
`FIG. 11A
`
`f 202
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`9
`
`

`

`Patent Application Publication May 11, 2006 Sheet 9 0f 14
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`US 2006/0097991 A1
`
`232
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`.
`
`220\‘
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`222
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`s
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`a
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`FIG. 13
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`
`

`

`Patent Application Publication May 11, 2006 Sheet 10 0f 14
`
`US 2006/0097991 A1
`
`272
`
`DSP
`
`HOST
`
`274
`
`ND 2 \—'27O
`
`260
`
`268
`
`262
`
`262
`
`11
`
`

`

`Patent Application Publication May 11, 2006 Sheet 11 0f 14
`
`US 2006/0097991 A1
`
`280 \
`
`DRIVE SENSING POINTS
`
`I
`
`READ OUTPUT FROM SENSING
`POINTS
`
`I
`
`PRODUCE AND ANALYZE
`TOUCHSCREEN DATA
`
`V
`
`COMPARE CURRENT DATA TO PAST
`DATA
`
`KN 00 N
`
`KN m .b.
`
`KM \N O0 oo oo 0)
`
`I
`COMPARISON K
`
`290
`
`PERFORM ACTION BASED ON
`
`FIG. 15
`
`12
`
`

`

`Patent Application Publication May 11, 2006 Sheet 12 0f 14
`
`US 2006/0097991 A1
`
`RECEIVE RAW DATA
`
`I
`
`FILTER RAW DATA
`
`I
`
`\00 O N
`
`306
`
`GENERATE GRADIENT DATA J
`
`y
`308
`CALCULATE BOUNDARIES FOR TOUCH J
`REGIONS
`
`I
`
`CALCULATE COORDINATES FOR EACH
`TOUCH REGION
`
`I
`
`PERFORM MULTIPOINT TRACKING
`
`O
`
`N
`
`FIG. 16
`
`13
`
`

`

`Patent Application Publication May 11, 2006 Sheet 13 0f 14
`
`US 2006/0097991 A1
`
`RAW DATA INCLUDING NOISE
`
`I
`
`II
`
`L4,II.I.._U LA
`
`TOUCH REGIONS
`
`G
`
`I:
`
`u
`
`E]
`
`FIG. 17D
`
`COORDINATES OF TOUCH REGIONS
`
`E
`
`I
`a=33_00 p=133.97
`x=707.07.04, y=331.323230
`
`@
`a=9.00 p= 3.33
`x=417.29, y=333.666667
`
`,
`
`,_
`
`a=35.00 p=133.74
`X=290.16, y=570.155950
`
`FIG. 17E
`
`FIG. 17B
`GRADIENT DATA
`
`FIG. 17C
`
`14
`
`

`

`Patent Application Publication May 11, 2006 Sheet 14 0f 14
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`US 2006/0097991 A1
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`356 358
`
`\ \
`
`\l
`
`)
`
`(- 350
`
`370
`
`2
`
`354
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`366
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`372
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`380
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`376
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`373
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`356
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`358
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`372
`
`350 f
`
`362
`
`FIG. 19
`
`15
`
`

`

`US 2006/0097991 A1
`
`May 11, 2006
`
`MULTIPOINT TOUCHSCREEN
`
`BACKGROUND OF THE INVENTION
`
`[0001] 1. Field of the Invention
`
`[0002] The present invention relates generally to an elec
`tronic device having a touch screen. More particularly, the
`present invention relates to a touch screen capable of sensing
`multiple points at the same time.
`
`[0003] 2. Description of the Related Art
`
`[0004] There exist today many styles of input devices for
`performing operations in a computer system. The operations
`generally correspond to moving a cursor and/or making
`selections on a display screen. By Way of example, the input
`devices may include buttons or keys, mice, trackballs, touch
`pads, joy sticks, touch screens and the like. Touch screens,
`in particular, are becoming increasingly popular because of
`their ease and versatility of operation as Well as to their
`declining price. Touch screens alloW a user to make selec
`tions and move a cursor by simply touching the display
`screen via a ?nger or stylus. In general, the touch screen
`recogniZes the touch and position of the touch on the display
`screen and the computer system interprets the touch and
`thereafter performs an action based on the touch event.
`
`[0005] Touch screens typically include a touch panel, a
`controller and a softWare driver. The touch panel is a clear
`panel With a touch sensitive surface. The touch panel is
`positioned in front of a display screen so that the touch
`sensitive surface covers the vieWable area of the display
`screen. The touch panel registers touch events and sends
`these signals to the controller. The controller processes these
`signals and sends the data to the computer system. The
`softWare driver translates the touch events into computer
`events.
`
`[0006] There are several types of touch screen technolo
`gies including resistive, capacitive, infrared, surface acous
`tic Wave, electromagnetic, near ?eld imaging, etc. Each of
`these devices has advantages and disadvantages that are
`taken into account When designing or con?guring a touch
`screen. In resistive technologies, the touch panel is coated
`With a thin metallic electrically conductive and resistive
`layer. When the panel is touched, the layers come into
`contact thereby closing a sWitch that registers the position of
`the touch event. This information is sent to the controller for
`further processing. In capacitive technologies, the touch
`panel is coated With a material that stores electrical charge.
`When the panel is touched, a small amount of charge is
`draWn to the point of contact. Circuits located at each corner
`of the panel measure the charge and send the information to
`the controller for processing.
`
`[0007] In surface acoustic Wave technologies, ultrasonic
`Waves are sent horizontally and vertically over the touch
`screen panel as for example by transducers. When the panel
`is touched, the acoustic energy of the Waves are absorbed.
`Sensors located across from the transducers detect this
`change and send the information to the controller for pro
`cessing. In infrared technologies, light beams are sent hori
`Zontally and vertically over the touch panel as for example
`by light emitting diodes. When the panel is touched, some of
`the light beams emanating from the light emitting diodes are
`interrupted. Light detectors located across from the light
`
`emitting diodes detect this change and send this information
`to the controller for processing.
`
`[0008] One problem found in all of these technologies is
`that they are only capable of reporting a single point even
`When multiple objects are placed on the sensing surface.
`That is, they lack the ability to track multiple points of
`contact simultaneously. In resistive and capacitive technolo
`gies, an average of all simultaneously occurring touch points
`are determined and a single point Which falls someWhere
`betWeen the touch points is reported. In surface Wave and
`infrared technologies, it is impossible to discern the exact
`position of multiple touch points that fall on the same
`horiZontal or vertical lines due to masking. In either case,
`faulty results are generated.
`[0009] These problems are particularly problematic in
`tablet PCs Where one hand is used to hold the tablet and the
`other is used to generate touch events. For example, as
`shoWn in FIGS. 1A and 1B, holding a tablet 2 causes the
`thumb 3 to overlap the edge of the touch sensitive surface 4
`of the touch screen 5. As shoWn in FIG. 1A, if the touch
`technology uses averaging, the technique used by resistive
`and capacitive panels, then a single point that falls some
`Where betWeen the thumb 3 of the left hand and the index
`?nger 6 of the right hand Would be reported. As shoWn in
`FIG. 1B, if the technology uses projection scanning, the
`technique used by infra red and SAW panels, it is hard to
`discern the exact vertical position of the index ?nger 6 due
`to the large vertical component of the thumb 3. The tablet 2
`can only resolve the patches shoWn in gray. In essence, the
`thumb 3 masks out the vertical position of the index ?nger
`6.
`
`SUMMARY OF THE INVENTION
`
`[0010] The invention relates, in one embodiment, to a
`touch panel having a transparent capacitive sensing medium
`con?gured to detect multiple touches or near touches that
`occur at the same time and at distinct locations in the plane
`of the touch panel and to produce distinct signals represen
`tative of the location of the touches on the plane of the touch
`panel for each of the multiple touches.
`
`[0011] The invention relates, in another embodiment, to a
`display arrangement. The display arrangement includes a
`display having a screen for displaying a graphical user
`interface. The display arrangement further includes a trans
`parent touch panel alloWing the screen to be vieWed there
`through and capable of recogniZing multiple touch events
`that occur at different locations on the touch sensitive
`surface of the touch screen at the same time and to output
`this information to a host device.
`
`[0012] The invention relates, in another embodiment, to a
`computer implemented method. The method includes
`receiving multiple touches on the surface of a transparent
`touch screen at the same time. The method also includes
`separately recognizing each of the multiple touches. The
`method further includes reporting touch data based on the
`recogniZed multiple touches.
`
`[0013] The invention relates, in another embodiment, to a
`computer system. The computer system includes a processor
`con?gured to execute instructions and to carry out opera
`tions associated With the computer system. The computer
`also includes a display device that is operatively coupled to
`
`16
`
`

`

`US 2006/0097991 Al
`
`May 11, 2006
`
`the processor. The computer system further includes a touch
`screen that is operatively coupled to the processor. The touch
`screen is a substantially transparent panel that is positioned
`in front of the display. The touch screen is con?gured to
`track multiple objects, Which rest on, tap on or move across
`the touch screen at the same time. The touch screen includes
`a capacitive sensing device that is divided into several
`independent and spatially distinct sensing points that are
`positioned throughout the plane of the touch screen. Each
`sensing point is capable of generating a signal at the same
`time. The touch screen also includes a sensing circuit that
`acquires data from the sensing device and that supplies the
`acquired data to the processor.
`
`[0014] The invention relates, in another embodiment, to a
`touch screen method. The method includes driving a plu
`rality of sensing points. The method also includes reading
`the outputs from all the sensing lines connected to the
`sensing points. The method further includes producing and
`analyZing an image of the touch screen plane at one moment
`in time in order to determine Where objects are touching the
`touch screen. The method additionally includes comparing
`the current image to a past image in order to determine a
`change at the objects touching the touch screen.
`
`[0015] The invention relates, in another embodiment, to a
`digital signal processing method. The method includes
`receiving raW data. The raW data includes values for each
`transparent capacitive sensing node of a touch screen. The
`method also includes ?ltering the raW data. The method
`further includes generating gradient data. The method addi
`tionally includes calculating the boundaries for touch
`regions base on the gradient data. Moreover, the method
`includes calculating the coordinates for each touch region.
`
`BRIEF DESCRIPTION OF THE DRAWINGS
`
`[0016] The invention Will be readily understood by the
`folloWing detailed description in conjunction With the
`accompanying draWings, Wherein like reference numerals
`designate like structural elements, and in Which:
`
`[0017] FIGS. 1A and 1B shoW a user holding conven
`tional touch screens.
`
`[0018] FIG. 2 is a perspective vieW of a display arrange
`ment, in accordance With one embodiment of the present
`invention.
`
`[0019] FIG. 3 shoWs an image of the touch screen plane
`at a particular point in time, in accordance With one embodi
`ment of the present invention.
`
`[0020] FIG. 4 is a multipoint touch method, in accordance
`With one embodiment of the present invention.
`
`[0021] FIG. 5 is a block diagram of a computer system, in
`accordance With one embodiment of the present invention.
`
`[0022] FIG. 6 is a partial top vieW of a transparent
`multiple point touch screen, in accordance With one embodi
`ment of the present invention.
`
`[0023] FIG. 7 is a partial top vieW of a transparent multi
`point touch screen, in accordance With one embodiment of
`the present invention.
`
`[0024] FIG. 8 is a front elevation vieW, in cross section of
`a display arrangement, in accordance With one embodiment
`of the present invention.
`
`[0025] FIG. 9 is a top vieW of a transparent multipoint
`touch screen, in accordance With another embodiment of the
`present invention.
`
`[0026] FIG. 10 is a partial front elevation vieW, in cross
`section of a display arrangement, in accordance With one
`embodiment of the present invention.
`
`[0027] FIGS. 11A and 11B are partial top vieW diagrams
`of a driving layer and a sensing layer, in accordance With one
`embodiment.
`
`[0028] FIG. 12 is a simpli?ed diagram of a mutual capaci
`tance circuit, in accordance With one embodiment of the
`present invention.
`
`[0029] FIG. 13 is a diagram of a charge ampli?er, in
`accordance With one embodiment of the present invention.
`
`[0030] FIG. 14 is a block diagram of a capacitive sensing
`circuit, in accordance With one embodiment of the present
`invention.
`
`[0031] FIG. 15 is a How diagram, in accordance With one
`embodiment of the present invention.
`
`[0032] FIG. 16 is a How diagram of a digital signal
`processing method, in accordance With one embodiment of
`the present invention.
`
`[0033] FIGS. 17A-E shoW touch data at several steps, in
`accordance With one embodiment of the present invention
`
`[0034] FIG. 18 is a side elevation vieW of an electronic
`device, in accordance With one embodiments of the present
`invention.
`
`[0035] FIG. 19 is a side elevation vieW of an electronic
`device, in accordance With one embodiments of the present
`invention.
`
`DETAILED DESCRIPTION OF THE
`INVENTION
`
`[0036] Embodiments of the invention are discussed beloW
`With reference to FIGS. 2-19. HoWever, those skilled in the
`art Will readily appreciate that the detailed description given
`herein With respect to these ?gures is for explanatory
`purposes as the invention extends beyond these limited
`embodiments.
`
`[0037] FIG. 2 is a perspective vieW of a display arrange
`ment 30, in accordance With one embodiment of the present
`invention. The display arrangement 30 includes a display 34
`and a transparent touch screen 36 positioned in front of the
`display 34. The display 34 is con?gured to display a
`graphical user interface (GUI) including perhaps a pointer or
`cursor as Well as other information to the user. The trans
`parent touch screen 36, on the other hand, is an input device
`that is sensitive to a user’s touch, alloWing a user to interact
`With the graphical user interface on the display 34. By Way
`of example, the touch screen 36 may alloW a user to move
`an input pointer or make selections on the graphical user
`interface by simply pointing at the GUI on the display 34.
`
`[0038] In general, touch screens 36 recogniZe a touch
`event on the surface 38 of the touch screen 36 and thereafter
`output this information to a ho st device. The ho st device may
`for example correspond to a computer such as a desktop,
`laptop, handheld or tablet computer. The host device inter
`prets the touch event and thereafter performs an action based
`
`17
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`

`

`US 2006/0097991 Al
`
`May 11, 2006
`
`on the touch event. Conventionally, touch screens have only
`been capable of recognizing a single touch event even When
`the touch screen is touched at multiple points at the same
`time (e.g., averaging, masking, etc.). Unlike conventional
`touch screens, hoWever, the touch screen 36 shoWn herein is
`con?gured to recognize multiple touch events that occur at
`different locations on the touch sensitive surface 38 of the
`touch screen 36 at the same time. That is, the touch screen
`36 alloWs for multiple contact points T1-T4 to be tracked
`simultaneously, i.e., if four objects are touching the touch
`screen, then the touch screen tracks all four objects. As
`shoWn, the touch screen 36 generates separate tracking
`signals 81-84 for each touch point T1-T4 that occurs on the
`surface of the touch screen 36 at the same time. The number
`of recognizable touches may be about 15. 15 touch points
`alloWs for all 10 ?ngers, tWo palms and 3 others.
`[0039] The multiple touch events can be used separately or
`together to perform singular or multiple actions in the host
`device. When used separately, a ?rst touch event may be
`used to perform a ?rst action While a second touch event
`may be used to perform a second action that is different than
`the ?rst action. The actions may for example include moving
`an object such as a cursor or pointer, scrolling or panning,
`adjusting control settings, opening a ?le or document, vieW
`ing a menu, making a selection, executing instructions,
`operating a peripheral device connected to the host device
`etc. When used together, ?rst and second touch events may
`be used for performing one particular action. The particular
`action may for example include logging onto a computer or
`a computer netWork, permitting authorized individuals
`access to restricted areas of the computer or computer
`netWork, loading a user pro?le associated With a user’s
`preferred arrangement of the computer desktop, permitting
`access to Web content, launching a particular program,
`encrypting or decoding a message, and/or the like.
`[0040] Recognizing multiple touch events is generally
`accomplished With a multipoint sensing arrangement. The
`multipoint sensing arrangement is capable of simultaneously
`detecting and monitoring touches and the magnitude of
`those touches at distinct points across the touch sensitive
`surface 38 of the touch screen 36. The multipoint sensing
`arrangement generally provides a plurality of transparent
`sensor coordinates or nodes 42 that Work independent of one
`another and that represent different points on the touch
`screen 36. When plural objects are pressed against the touch
`screen 36, one or more sensor coordinates are activated for
`each touch point as for example touch points Ti -T4. The
`sensor coordinates 42 associated With each touch point
`T1-T4 produce the tracking signals 81-84.
`
`[0041] In one embodiment, the touch screen 36 includes a
`plurality of capacitance sensing nodes 42. The capacitive
`sensing nodes may be Widely varied. For example, the
`capacitive sensing nodes may be based on self capacitance
`or mutual capacitance. In self capacitance, the “self ’ capaci
`tance of a single electrode is measured as for example
`relative to ground. In mutual capacitance, the mutual capci
`tance betWeen at least ?rst and second electrodes is mea
`sured. In either cases, each of the nodes 42 Works indepen
`dent of the other nodes 42 so as to produce simultaneously
`occurring signals representative of different points on the
`touch screen 36.
`
`[0042] In order to produce a transparent touch screen 36,
`the capacitance sensing nodes 42 are formed With a trans
`
`parent conductive medium such as indium tin oxide (ITO).
`In self capacitance sensing arrangements, the transparent
`conductive medium is patterned into spatially separated
`electrodes and traces. Each of the electrodes represents a
`different coordinate and the traces connect the electrodes to
`a capacitive sensing circuit. The coordinates may be asso
`ciated With Cartesian coordinate system (x and y), Polar
`coordinate system (r, 6) or some other coordinate system. In
`a Cartesian coordinate system, the electrodes may be posi
`tioned in columns and roWs so as to form a grid array With
`each electrode representing a different x, y coordinate.
`During operation, the capacitive sensing circuit monitors
`changes in capacitance that occur at each of the electrodes.
`The positions Where changes occur and the magnitude of
`those changes are used to help recognize the multiple touch
`events. A change in capacitance typically occurs at an
`electrode When a user places an object such as a ?nger in
`close proximity to the electrode, i.e., the object steals charge
`thereby affecting the capacitance.
`[0043] In mutual capacitance, the transparent conductive
`medium is patterned into a group of spatially separated lines
`formed on tWo different layers. Driving lines are formed on
`a ?rst layer and sensing lines are formed on a second layer.
`Although separated by being on different layers, the sensing
`lines traverse, intersect or cut across the driving lines
`thereby forming a capacitive coupling node. The manner in
`Which the sensing lines cut across the driving lines generally
`depends on the coordinate system used. For example, in a
`Cartesian coordinate system, the sensing lines are perpen
`dicular to the driving lines thereby forming nodes With
`distinct x and y coordinates. Alternatively, in a polar coor
`dinate system, the sensing lines may be concentric circles
`and the driving lines may be radially extending lines (or vice
`versa). The driving lines are connected to a voltage source
`and the sensing lines are connected to capacitive sensing
`circuit. During operation, a current is driven through one
`driving line at a time, and because of capacitive coupling,
`the current is carried through to the sensing lines at each of
`the nodes (e.g., intersection points). Furthermore, the sens
`ing circuit monitors changes in capacitance that occurs at
`each of the nodes. The positions Where changes occur and
`the magnitude of those changes are used to help recognize
`the multiple touch events. A change in capacitance typically
`occurs at a capacitive coupling node When a user places an
`object such as a ?nger in close proximity to the capacitive
`coupling node, i.e., the object steals charge thereby affecting
`the capacitance.
`[0044] By Way of example, the signals generated at the
`nodes 42 of the touch screen 36 may be used to produce an
`image of the touch screen plane at a particular point in time.
`Referring to FIG. 3, each object in contact With a touch
`sensitive surface 38 of the touch screen 36 produces a
`contact patch area 44. Each of the contact patch areas 44
`covers several nodes 42. The covered nodes 42 detect
`surface contact While the remaining nodes 42 do not detect
`surface contact. As a result, a pixilated image of the touch
`screen plane can be formed. The signals for each contact
`patch area 44 may be grouped together to form individual
`images representative of the contact patch area 44. The
`image of each contact patch area 44 may include high and
`loW points based on the pressure at each point. The shape of
`the image as Well as the high and loW points Within the
`image may be used to differentiate contact patch areas 44
`that are in close proximity to one another. Furthermore, the
`
`18
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`

`US 2006/0097991 A1
`
`May 11, 2006
`
`current image, and more particularly the image of each
`contact patch area 44 can be compared to previous images
`to determine What action to perform in a host device.
`[0045] Referring back to FIG. 2, the display arrangement
`30 may be a stand alone unit or it may integrated With other
`devices. When stand alone, the display arrangement 32 (or
`each of its components) acts like a peripheral device (moni
`tor) that includes its oWn housing and that can be coupled to
`a host device through Wired or Wireless connections. When
`integrated, the display arrangement 30 shares a housing and
`is hard Wired into the host device thereby forming a single
`unit. By Way of example, the display arrangement 30 may be
`disposed inside a variety of host devices including but not
`limited to general purpose computers such as a desktop,
`laptop or tablet computers, handhelds such as PDAs and
`media players such as music players, or peripheral devices
`such as cameras, printers and/or the like.
`
`[0046] FIG. 4 is a multipoint touch method 45, in accor
`dance With one embodiment of the present invention. The
`method generally begins at block 46 Where multiple touches
`are received on the surface of the touch screen at the same
`time. This may for example be accomplished by placing
`multiple ?ngers on the surface of the touch screen. FolloW
`ing block 46, the process How proceeds to block 47 Where
`each of the multiple touches is separately recogniZed by the
`touch screen. This may for example be accomplished by
`multipoint capacitance sensors located Within the touch
`screen. Following block 47, the process How proceeds to
`block 48 Where the touch data based on multiple touches is
`reported. The touch data may for example be reported to a
`host device such as a general purpose computer.
`
`[0047] FIG. 5 is a block diagram of a computer system 50,
`in accordance With one embodiment of the present inven
`tion. The computer system 50 may correspond to personal
`computer systems such as desktops, laptops, tablets or
`handhelds. By Way of example, the computer system may
`correspond to any Apple or PC based computer system. The
`computer system may also correspond to public computer
`systems such as information kiosks, automated teller
`machines (ATM), point of sale machines (POS), industrial
`machines, gaming machines, arcade machines, vending
`machines, airline e-ticket terminals, restaurant reservation
`terminals, customer service stations, library terminals, leam
`ing devices, and the like.
`
`[0048] As shoWn, the computer system 50 includes a
`processor 56 con?gured to execute instructions and to carry
`out operations associated With the computer system 50. For
`example, using instructions retrieved for example from
`memory, the processor 56 may control the reception and
`manipulation of input and output data betWeen components
`of the computing system 50. The processor 56 can be a
`single-chip processor or can be implemented With multiple
`components.
`
`[0049] In most cases, the processor 56 together With an
`operating system operates to execute computer code and
`produce and use data. The computer code and data may
`reside Within a program storage block 58 that is operatively
`coupled to the processor 56. Program storage block 58
`generally provides a place to hold data that is being used by
`the computer system 50. By Way of example, the program
`storage block may include Read-Only Memory (ROM) 60,
`Random-Access Memory (RAM) 62, hard disk drive 64
`
`and/or the like. The computer code and data could also
`reside on a removable storage medium and loaded or
`installed onto the computer system When needed. Remov
`able storage mediums include, for example, CD-ROM,
`PC-CARD, ?oppy disk, magnetic tape, and a netWork com
`ponent.
`
`[0050] The computer system 50 also includes an input/
`output (I/O) controller 66 that is operatively coupled to the
`processor 56. The (U0) controller 66 may be integrated With
`the processor 56 or it may be a separate component as
`shoWn. The U0 controller 66 is generally con?gured to
`control interactions With one or more I/O devices. The U0
`controller 66 generally operates by exchanging data betWeen
`the processor and the I/O devices that desire to communicate
`With the processor. The I/O devices and the I/O controller
`typically communicate through a data link 67. The data link
`67 may be a one Way link or tWo Way link. In some cases,
`the I/O devices may be connected to the I/O controller 66
`through Wired connections. In other cases, the I/O devices
`may be connected to the I/O controller 66 through Wireless
`connections. By Way of example, the data link 67 may
`correspond to PS/2, USB, FireWire, IR, RF, Bluetooth or the
`like.
`
`[0051] The computer system 50 also includes a display
`device 68 that is operatively coupled to the processor 56.
`The display device 68 may be a separate component (periph
`eral device) or it may be integrated With the processor and
`program storage to form a desktop computer (all in one
`machine), a laptop, handheld or tablet or the like. The
`display device 68 is con?gured to display a graphical user
`interface (GUI) including perhaps a pointer or cursor as Well
`as other information to the user. By Way of example, the
`display device 68 may be a monochrome display, color
`graphics adapter (CGA) display, enhanced graphics adapter
`(EGA) display, variable-graphics-array (VGA) display,
`super VGA display, liquid crystal display (e.g., active
`matrix, passive matrix and the like), cathode ray tube (CRT),
`plasma displays and the like.
`
`[0052] The computer system 50 also includes a touch
`screen 70 that is operatively coupled to the processor 56. The
`touch screen 70 is a transparent panel that is positioned in
`front of the display device 68. The touch screen 70 may be
`integrated With the display device 68 or it may be a separate
`component. The touch screen 70 is con?gured to receive
`input from a user’s touch and to send this information to the
`processor 56. In most cases, the touch screen 70 recogniZes
`touches and the position and magnitude of touches on its
`surface. The touch screen 70 reports the touches to the
`processor 56 and the processor 56 interprets the touches in
`accordance With its programming. For example, the proces
`sor 56 may initiate a task in accordance With a particular
`touch.
`
`[0053] In accordance With one embodiment, the touch
`screen 70 is capable of tracking multiple objects, Which rest
`on, tap on, or move across the touch sensitive surface of the
`touch screen at the same time. The multiple objects may for
`example correspond to ?ngers and palms. Because the touch
`screen is capable of tracking multiple objects, a user may
`perform several touch initiated tasks at the same time. For
`example, the user may select an onscreen button With one
`?nger, While moving a cursor With another ?nger. In addi
`tion, a user may move a scroll bar With one ?nger While
`
`19
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`US 2006/0097991 A1
`
`May 11, 2006
`
`selecting an item from a menu With another ?nger. Further
`more, a ?rst object may be dragged With one ?nger While a
`second object may be dragged With another ?nger. More
`over, gesturing may be performed With more than one ?nger.
`
`[0054] To elaborate, the touch screen 70 generally
`includes a sensing device 72 con?gured to detect an object
`in close proximity thereto and/or the pressure exerted
`thereon. The sensing device 72 may be Widely varied. In one
`particular embodiment, the sensing device 72 is divided into
`several independent and spatially distinct sensing points,
`nodes or regions 74 that are positioned throughout the touch
`screen 70. The sensing points 74, Which are typically hidden
`from vieW, are dispersed about the touch screen 70 With each
`sensing point 74 representing a different position on the
`surface of the touch screen 70 (or touch screen plane). The
`sensing points 74 may be positioned in a grid or a pixel array
`Where each pixilated sensing point 74 is capable of gener
`ating a signal at the same time. In the simplest case, a signal
`is produced each time an object is positioned over a sensing
`point 74. When an object is placed over multiple sensing
`points 74 or When the object is moved betWeen or over
`multiple sensing point 74