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`US 20(140252109A1
`
`(19} United States
`(12) Patent Application Publication (10) Pub. No.: US 2004/0252109 A1
`
`Trent, JR. ct al. Dec. 16, 2004 (43) Pub. Date:
`
`
`(54} ClDSED-LOOP SENSOR ON A SOLID-STATE
`OBJECT POSITION DETECTOR
`
`Related [1.8. Application Data
`
`(75)
`
`Inventors: Raymond A. Then! JR., San Jose, CA
`(US); Scott J. Shaw, l'I‘ren‘ionl, CA
`(US); David W. Gillespie, Los Gatos.
`(“A {US}; Christopher Heiny, Boulder
`Creek, CA (US); Mark A. Huie, San
`Carlos, CA(US)
`
`Correspondence Address:
`SIERRA l’A'l'ENT GROUP, LTD.
`1: 0 BOX 6149
`S'l'A'l'lCLlNlC, NV 89449 (US)
`
`(73) Assignee: Synaptics, Inc.
`
`(21) App1_N(}_:
`
`101338355
`
`{22
`
`Filed:
`
`Jan. 7, 2003
`
`(6(1) Provisional application No. (Slit-"372,009, filed on Apr.
`11, 2002.
`
`Publication Classification
`
`G09G 5f00
`Int. CL"
`(51}
`(52] U.S. CI. 3451174
`
`‘
`y
`,
`A95] RAL—l
`‘
`(57)
`The present disclosure discloses an object position detector.
`The object position detector comprises a
`touch sensor
`formed as a closed loop and having a physical constraint
`formed on an upper surface of the touch sensor and coex-
`lensive with the closed loop. The touch sensor is configured
`to sense motion of an object proximate lo the closed loop.
`The object position detector also comprises a processor
`coupled to the touch sensor and is programmed to generate
`an action in response to the motion on Ihe touch sensor.
`
`
`
`20
`
`
`22
`
`
`
`26
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`1
`
`CYPRESS 1005
`CYPRESS 1005
`
`1
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`

`

`Patent Application Publication Dec. 16,2004 Sheet 1 of 17
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`US 2004/0252109 A1
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`10
`
`12
`
`
`
`Closed
`LOOP Path
`Decoder
`
`Sensor
`
`14
`
`Mesqagc
`Generator
`
`Fig. l
`
`
`
`
`
`
`
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`20
`
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`22
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`
`
`
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`26
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`
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`2
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`

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`Patent Application Publication Dec. 16,2004 Sheet 2 of 17
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`US 2004/0252109 A1
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`30\
`
`34
`
`/
`
`$90 @w
`
`Fig. 5
`
` Him
`
`3
`
`

`

`Patent Application Publication Dec. 16,2004 Sheet 3 of 17
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`US 2004/0252109 A1
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`OQAU :1
`
`Fig. 11
`
`Fig. 12
`CO
`Fig- 16
`
`Fig. 13 Fig. 14 Fig. 15
`8
`Fig. 17
`
`Fig. 23
`
`Fig. 22
`
`4
`
`

`

`Patent Application Publication Dec. 16,2004 Sheet 4 of 17
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`US 2004/0252109 A1
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`62
`
`/ I
`
`F—-'_-—‘
`
`5
`
`

`

`Patent Application Publication Dec. 16,2004 Sheet 5 of 17
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`US 2004/0252109 A1
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`93
`
`6
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`

`

`
`
`
`
`7
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`

`

`Patent Application Publication Dec. 16,2004 Sheet 7 of 17
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`US 2004/0252109 A1
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`
`
`Fig. 31
`
`8
`
`

`

`Patent Application Publication Dec. 16,2004 Sheet 8 of 17
`
`US 2004/0252109 A1
`
`inCapacitance
`Change
`
`X or Y Axis Sensor Inputs
`
`Fig. 32
`
`9
`
`

`

`Patent Application Publication Dec. 16,2004 Sheet 9 of 17
`
`US 2004/0252109 A1
`
`4._.
`
`110
`
`.\
`
`115
`
`114
`
`112
`
`
`
`10
`
`

`

`Patent Application Publication Dec. 16,2004 Sheet 10 0f 17
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`US 2004/0252109 A1
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`130
`
`142
`
`144
`
`
`
`11
`
`11
`
`

`

`Patent Application Publication Dec. 16,2004 Sheet 11 0f 17
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`US 2004/0252109 A1
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`150
`
`Capacitance
`
`
`
`Measurement--——-hv
`
`(3(0)
`
`0(1)
`
`0(2)
`
`C(3)
`
`(3(4)
`
`(3(5)
`
`12
`
`12
`
`

`

`Patent Application Publication Dec. 16,2004 Sheet 12 0f 17
`
`US 2004/0252109 A1
`
`Determine which electrode has
`
`the largest capacitance
`
`Measurement
`
`Fit capacitance measurements of
`electrode with largest capacitance
`and its neighboring electrodes to an
`inverted parabola
`
`compensate for non-linearitics
`
`Calculate the center point
`of the parabola
`
`Reduce the calculated center
`point by Module N, if necessary
`
`Pass calculated center point value
`through a non-linear function to
`
`Fig. 39
`
`13
`
`13
`
`

`

`Patent Application Publication Dec. 16,2004 Sheet 13 of 17
`
`US 2004/0252109 A1
`
`
`Locate peak electrode i
`
`
`
`Rotate coordinate system by renumbering
`each electrode j to 0-i+N/2) Modulo N,
`
`thus centering 1'
`
`
`
`
`Reverse rotate X’=(X+i-N/2) Modulo N,
`X ’ is final input object location
`
`Calculate mathematical centroid X
`
`Fig. 41
`
`14
`
`14
`
`

`

`Patent Application Publication Dec. 16,2004 Sheet 14 0f 17
`
`US 2004/0252109 A1
`
`Compute numerator N as
`N= Sum(sin(i *2 pi/N) * C(i))
`
`obtain angular position
`
`Compute denominator D as
`D= Sum(cos(i*2 pi/N) * C(w
`
`Compute atan2(N,D) to
`
`Fig. 42
`
`15
`
`15
`
`

`

`Patent Application Publication Dec. 16,2004 Sheet 15 0f 17
`
`US 2004/0252109 A1
`
`Compute numerator N as
`N: 3
`
`angular position
`
`Compute denominator D as
`D=fc
`
`ComputeQWD) to obtain
`
`Fig. 43
`
`16
`
`16
`
`

`

`Patent Application Publication Dec. 16,2004 Sheet 16 0f 17
`
`US 2004/0252109 A1
`
`Calculate NewPos
`
`
`
`
` Copy NewPos
`
`object previously present
`
`into OidPos
`
`
`on the sensor?
`
`Was an
`
`
`two samples ( Motion = NewPos - OidPos)
`
`
`Determine motion betxveen
`
`
`
`
`
`
`Motion is
`
`
`
`Motion is
`Less than
`
`l 80 0 or
`
`-] 80°
`
`
`more ?
`
`
` Subtract 360 a
`
`from Motion
`
`
`?
`
`Yes
`
`Add 3 60 °
`to Motion
`
`
`
`Fig.44'
`
`17
`
`17
`
`

`

`Patent Application Publication Dec. 16,2004 Sheet 17 0f 17
`
`US 2004/0252109 A1
`
`
`
`
`
`Determine a first point and a
`second point on the closed
`loop sensor
`
`Calculate the distance between
`
`the first and second points
`
`Calculate the angles correSponding
`to the first and second points
`
`indicate direction of motion
`
`Subtract the angle of the second point
`from the angle of the first point to
`get a result
`
`Use the sign of the result to
`
`Fig. 45
`
`18
`
`18
`
`

`

`US 2004/0252109 A1
`
`Dec. 16, 2004
`
`CLOSED-LOOP SENSOR ON A SOLID-STATE
`OBJECT POSITION DETECTOR
`
`CROSS-REFERENCE T0 REIA'I‘EI)
`APPI .1 CAT] ON
`
`[0001] This application claims the benefit of US. Provi-
`sional Application Serial No. 60t'372,009, filed Apr. ll,
`2002.
`
`BACKGROUND
`
`[0002] User interfaces on digital information processing
`devices often have more information and options than can be
`easily handled with buttons or other physical controls. In
`particular, scrolling of documents and data, selection of
`menu items, and continuous value controls, such as volume
`controls, can be ditticult to control with buttons and general
`purpose pointing devices.
`these buttons and pointing
`devices are inherently limited in how far they can move or
`how many options can be selected. For example, a computer
`mouse. though it can move a pointer or cursor indefinitely,
`has limits to how far it can move without being picked up
`and repositioned, which limits its usability in these situa-
`tions.
`
`[0003] Solutions to this problem have included:
`
`a. Keys, such as "page up" and “page down"
`[0004]
`and arrow keys, that are specifically designated to
`maneuver through or control data;
`
`b. Provisions for scrollbars in a user interface
`[0005]
`which can be used to scroll data long distances by
`using a standard computer pointing device control—
`ling a cursor;
`
`c. Similarly controlled (as in b.) hierarchical
`[0006]
`menus or choices;
`
`d. Graphical user interface elements such as
`[0007]
`"slider bats” and “spin controls" to vary a parameter
`over an arbitrary range;
`
`e. Scrolling “wheels” on standard pointing
`[0008]
`devices;
`
`f. Physical knob controls, which, when used to
`[0009]
`control a user interface are often referred to in the art
`
`as “jog dials". Some knobs and dials output quadra-
`ture signals to indicate direction of motion;
`
`rely on optically or
`that
`g. Trackballs
`[0010]
`mechanically sensed spherical controls to provide
`two-dimensional sensing; and
`
`h. A capacitive two-dimensional object posi-
`[0011]
`tion sensor that can be used for scrolling by provid—
`ing a “scrolling region”, where users can slide their
`lingers to generating scrolling actions.
`
`[0012] The disadvantages of these prior solutions are as
`follows:
`
`a. Designated Keys: These typically require
`[0013]
`designated space on the keyboard as well as sup—
`porting electronics and physical structures. Keys
`usually limit the control they ofi'er to the user over
`the information being scrolled or the function being
`performed to distinct values. For example, page up
`
`19
`
`and page down keys enable the user to increment
`through a document at a constant rate of page by
`page only.
`b. Scroll bars controlled by a pointing device
`[0014]
`and a cursor: These elements require the user to
`move long distances across a display andtor select
`relatively small controls in order to scroll the data.
`Additionally, these scroll bars take up room on the
`display that can be used for other purposes.
`[0015]
`c. Hierarchical menus controlled by a pointing
`device or by key combinations: These have a similar
`problem to scroll bars, in terms ofthe complexity of
`the targeting task that faces the user. First, the user
`must hit a small target near the edge of a screen, and
`then the user must navigate along narrow paths to
`open up additional layers of menu hierarchy. Short-
`cut keys, which usually consist of key combinations,
`are typically non—intuitive and hard to remember.
`d. “Sliders" and "spin controls" controlled by
`[0016]
`a pointing device or by key combinations: These
`have targeting problems similar to scroll bars and
`hierarchical menus (sometimes exacerbated by the
`targets usually being even smaller than in the cases
`of scrollbars and menus).
`[0017]
`e. Physical Scroll Wheels on mice: The user is
`unable to scroll very far with these wheels due to
`mechanical limitations in how far the user can move
`the wheel
`in a single stroke. These mechanical
`limitations are because of the construction of the
`wheel itself or because of interactions between the
`
`wheel and nearby physical features (such as the
`wheel mounting or the device housing}. The limits
`on the practicalfcomfortable length of the basic fin-
`ger motion also severely restrict the ability of the
`user to scroll significant distances in one stroke.
`Additionally, these wheels are mechanically com-
`plex and take up a lot of space.
`E. Physical knobs or “Jog Dial" controls:
`[0013]
`These have the disadvantages of being relatively
`large and mechanically complex. Similar to the
`scroll wheel, the knob or dial requires some amount
`of
`friction to limit accidental activation, which
`increases the ditficulty of line adjustments. Addition-
`ally, it is difficult to use a physical knob or dial with
`a great degree of accuracy, and the knob or dial
`inherently has inertia that may cause overshoot in
`large motions. The physical knobs or dials are often
`mechanically limited in range ofrotation imposed by
`the construction or by the interactions of the knob or
`dial with nearby physical features.
`[0019]
`g. Trackballs: These are similar to the physical
`knobs in that they have the disadvantages of being
`bulky and mechanically complex. The trackball is
`difficult to use with a great degree of accuracy, and
`the trackball inherently has inertia that may cause
`overshoot in large motions. Additionally, the track-
`ball presents additional complexity in that it presents
`control of two dimensions of motion in a way that
`makes it difficult for users to limit their inputs to a
`single dimension. Finally, the input is limited either
`by the construction of the trackball and its housing,
`or by natural limits on comfortablerpractical finger
`motion, or both.
`
`19
`
`

`

`US 2004/0252109 A1
`
`Dec. 16, 2004
`
`h. Scroll Regions: These are limited by the
`[0020]
`physical limitation that a user’s finger will eventually
`reach the end of the scrolling region and the user will
`have to lift their finger, replace it on the sensor inside
`the region, and continue the motion. The user must
`perform many repetitive motions of the same finger
`to scroll long distances with a scroll region.
`
`[0021] The disadvantages of the prior art can be remedied
`by devising a user interface that enables scrolling, selecting,
`and varying controls over a long range of possible positions
`and values.
`
`SUMMARY
`
`[0022] The drawbacks and disadvantages of the prior art
`are overcome by a closed-loop sensor on a solid-state object
`position detector.
`
`[0023] The present disclosure discloses a solid-state object
`position detector. The solid-state object position detector
`comprises a touch sensor formed as a closed loop having a
`physical constraint formed on an upper surface ot'the touch
`sensor and coextensive with the closed loop. The touch
`sensor is configured to sense motion of an object proximate
`to the closed loop. The object position detector also corn-
`prises a processor coupled to the touch sensor and is
`programmed to generate an action in reSponse to the motion
`on the touch sensor.
`
`[0024] The present disclosure also discloses a solid-state
`object position detector, comprising a
`two-dimensional
`touch sensor having a tactile guide formed on an upper
`surface of, and coextensive with, the two—dimensional touch
`sensor. The two—dimensional touch sensor is configured to
`sense motion of an object proximate to the two-dimensional
`touch sensor. The solid-state object position detector also
`comprises a processor coupled to the two-dimensional touch
`sensor and configured to report only one variable indicating
`the position, such as the angular position, of an object
`proximate to the two—dimensional touch sensor. The proccs~
`sor is programmed to generate an action in response to the
`motion on the tWo-dimensional touch sensor.
`
`[0025] The present disclosure also discloses a combina-
`tion comprising a solid-state object position detector, a
`pointing input device, and a processor. The solid-state object
`position detector has a touch sensor formed as a closed loop.
`The solid-state object position detector has a tactile guide
`formed on an upper surface of the touch sensor and coex-
`tensive with the closed loop. The touch sensor is configured
`to sense a first position ot'an object proximate to the closed
`loop. The pointing input device is disposed proximate to the
`solid—state object position detector and is configured to sense
`a first pointing input of a user. The processor is coupled to
`the solid-state object position detector and to the pointing
`input device. The processor is programmed to generate at
`least one action in response to the first position and at least
`one action in response to the first pointing input. The
`pointing inputdevice can be a mouse, a touch pad, a pointing
`stick, a slider, a joystick, a touch screen, a trackball or
`another solid-state object position detector.
`
`[0026] The present disclosure also discloses another
`embodiment of a combination comprising a solid—state
`object position detector, a control input device, and a pro-
`cessor. The solid-state object position detector has a touch
`
`sensor formed as a closed loop. The solid-state object
`position detector has a tactile guide formed on an upper
`surface of the touch sensor and coextensive with the closed
`loop. The touch sensor is configured to sense a first position
`of an object proximate to the closed loop. The control-input
`device is disposed proximate to the solid-state object posi~
`tion detector and is configured to sense a first control input
`of a user. The processor is coupled to the solid-state object
`position detector and to the control input device. The pro-
`cessor is programmed to generate at
`least one action in
`response to the first position and at
`least one action in
`response to the first control input. The control input device
`can be a button, a key, a touch sensitive zone, a scrolling
`region, a scroll wheel, a jog dial, a slider, a touch screen, or
`another solid-state object position detector.
`
`[0027] The present disclosure also discloses a solid-state
`object position detector, comprising a touch sensor having a
`first electrode and a plurality of second electrodes disposed
`in a one—dimensional closed loop and proximate to the first
`electrode. The solid-state object position detector also com-
`prises a processor coupled to the touch sensor. The processor
`generates an action in response to user input on the touch
`sensor. The complexity of the sensing circuitry used in the
`plurality of second electrodes can be reduced, such that
`when only relative positioning is necessary, at least two of
`the plurality of second electrodes are electrically connected
`or wired together.
`
`[0028] The present disclosure also discloses a combina-
`tion comprising a solid-state object position detector, a touch
`pad, and a processor. The solid-state object position detector
`comprises a touch sensor having a first electrode and a
`plurality ofsecond electrodes disposed in a one-dimensional
`closed loop and proximate to the first electrode. The touch
`pad has a plurality of X electrodes and a plurality of Y
`electrodes. The first electrode is electrically coupled to at
`least one of the plurality of X electrodes and the plurality of
`Y electrodes. The processor is coupled to the touch sensor
`and to the input device. The processor generates an action in
`response to user input on at least one of the touch sensor and
`the touch pad. The complexity of the sensing circuitry used
`in the plurality of second electrodes can be reduced, such
`that when only relative positioning is necessary, at least two
`of the plurality of second electrodes are electrically con-
`nected or wired together.
`
`[0029] The present disclosure also discloses a solid—state
`object position detector, comprising a touch sensor having a
`plurality of interleaving electrodes disposed proximate to a
`one-dimensional closed loop; wherein each electrode is
`interdigitated with an adjacent neighboring electrode. The
`solid-state object position detector also comprises a proces-
`sor coupled to the touch sensor. The processor generates an
`action in response to user input on the touch sensor.
`
`[0030] The present disclosure also diScloses a solid-state
`object position detector, comprising a touch sensor having a
`plurality of self-interpolating electrodes disposed proximate
`to a closed loop. The solid-state object position detector also
`comprises a processor coupled to the touch sensor. The
`processor generates an action in response to user input on the
`touch sensor.
`
`[0031] The present disclosure also discloses a method of
`calculating a position of an object on an object position
`detector comprising receiving positional data from the
`
`20
`
`20
`
`

`

`US 2004/0252109 A1
`
`Dec. 16, 2004
`
`object on a touch sensor having a closed loop and interpo-
`lating the positional data to determine a position of the
`object on the one—dimensional closed loop. The interpolating
`aspect of the method further includes performing a quadratic
`lilting algorithm, a centroid interpolation algorithm, a trigo-
`nometric weighting algorithm, or a quasintrigonorrtetric
`weighting algorithm.
`
`[0032] The present disclosure also discloses a method of
`determining motion of an object on a touch sensor of an
`object position detector. The method comprises receiving
`data of a first position of the object on a closed loop on a
`touch sensor of the object position detector, receiving data of
`a second position of the object on the closed loop, and
`calculating motion from the second position and the first
`position. The method can further comprise determining if
`the motion is equal to or greater than a maximum angle and
`adjusting the motion based on whether the motion is equal
`or greater than the maximum angle. The method of adjusting
`the motion can be subtracting 360° from the motion. The
`method can further comprise determining if the motion is
`less than a minimum angle and adjusting the motion based
`on whether the motion is less than the minimum angle. The
`method of adjusting the motion can be adding 360“ to the
`motion.
`
`BRIEF DESCRIPTION OF FIGURES
`
`[0033] Referring now to the figures, wherein like elements
`are numbered alike:
`
`[0034] FIG. 1 illustrates a block diagram of a solid-state
`closed-loop sensor;
`
`[0035] FIG. 2 illustrates a location of a closed—loop sensor
`on a laptop near a keyboard;
`
`[0036] FIG. 3 illustrates a closed-loop sensor disposed on
`a conventional pointing device;
`
`[0037] FIG. 4 illustrates wedge-shaped electrodes of a
`closed—loop sensor;
`
`[0038] FIG. 5 illustrates lightning-bolt-shaped electrodes
`of a closed-loop sensor;
`
`[0039] FIG. 6 illustrates triangle-shaped electrodes of a
`closed-loop sensor;
`
`[0040] FIG. 7 illustrates rectangular-shaped electrodes
`that may he used in a linear section of a closed-loop sensor;
`
`[0041] FIG. 8 illustrates rectangular—shaped electrodes
`that may be used in a rectangular-shaped closed-loop sensor;
`
`[0042] FIG. 9 illustrates another example of triangle-
`shaped electrodes of a closed-loop sensor;
`
`[0043] FIG. 10 illustrates spiral-shaped electrodes of a
`closed—loop sensor;
`
`FIGS. 11 to 17 illustrate various shapes of the path
`[0044]
`utilized on a closed-loop sensor;
`
`[0047] FIG. 20 illustrates a cross-sectional view of
`U-shaped depressed grooves that define the path on a
`closed—loop sensor;
`
`[0048] FIG. 21 illustrates a cross—sectional view of a bezel
`that defines the path on a closed-loop sensor;
`
`[0049] FIGS. 22 and 23 illustrate the motions of an input
`object on a closed-Imp sensor and the ell’ects on a host
`device;
`
`[0050] FIG. 24 illustrates a motion on a closed-loop
`sensor for navigating menus;
`
`[0051] FIG. 25 illustrates a motion on a closed-loop
`sensor for vertically navigating menus using an additional
`key;
`
`[0052] FIG. 26 illustrates a motion on a closedvloop
`sensor for horizontally navigating within open menus;
`
`[0053] FIG. 27 illustrates a motion on a closed—loop
`sensor for a value setting control;
`
`[0054] FIG. 28 illustrates a closed-loop sensor electrically
`connected to a touch pad;
`
`[0055] FIG. 29 illustrates the potential electrical connec-
`tions of two closed-loop sensors to a touch pad;
`
`[0056] FIG. 30 illustrates several closed-loop sensors
`electrically connected to a touch pad;
`
`[005?] FIG. 31 illustrates two closed-loop sensors with
`indicator electrodes electrically connected to a touch pad;
`
`[0058] FIG. 32 illustrates a graph of the signals from a
`closed—loop sensor with an indicator electrode electrically
`connected to a touch pad;
`
`[0059] FIG. 33 illustrates a top view of an exemplary
`closed-loop sensor;
`
`[0060] FIG. 34 illustrates a side view of the cross-section
`of the exemplary closed-loop sensor of FIG. 33;
`
`[0061] FIG. 35 illustrates the lightning-boll—shaped elec—
`trodes of an exemplary closed-loop sensor having an interior
`opening and four exterior regions;
`
`[0062] FIG. 36 illustrates a plurality of closed-loop sen-
`sors to vary the settings of audio controls;
`
`[0063] FIG. 37 illustrates two sets of two closed-loop
`sensors formed concentrically about a single origin for an
`audio system;
`
`[0064] FIG. 38 illustrates four closed-loop sensors for an
`audio system formed in concentric circles about a single
`origin;
`
`[0065] FIG. 39 is a [low chart of a method of calculating
`a position of an object on a closed-loop sensor by perform-
`ing a quadratic fitting algorithm;
`
`[0045] FIG. 18 illustrates a cross-sectional view of
`V-shaped depressed grooves that define the path on a closed-
`loop sensor;
`
`[0066] FIG. 40 is a graph of the second quadratic fitting
`step in which the three capacitance measurements from the
`three adjacent electrodes are fitted to an inverted parabola;
`
`[0046] FIG. 19 illustrates a cross—sectional view of a
`raised projection that defines the path on a closed-loop
`sensor;
`
`[0067] FIG. 41 is a flow chart of a method of calculating
`a position of an object on a closed-loop sensor by perform-
`ing a centroid interpolation algorithm;
`
`21
`
`21
`
`

`

`US 2004/0252109 A1
`
`Dec. 16, 2004
`
`[0068] FIG. 42 is a flow chart of a method ot'calculating
`a position of an object on a closed-loop sensor by perform-
`ing a trigonometric weighting algorithm;
`
`[0069] FIG. 43 is a flow chart of a method of calculating
`a position of an object on a closcddoop sensor by perform-
`ing a quasi-trigonometric weighting algorithm;
`
`[0070] FIG. 44 is a flow chart of a method of determining
`relative motion of an object on a closed-loop sensor; and
`
`[0071] FIG. 45 is a flow chart of a method of ttsing the
`angular component to determine the sign of the traversal
`along the closed—loop path.
`
`DETAILED DESCRIPTION
`
`[0072] Those of ordinary skill in the art will realize that
`the following description of the present invention is illus-
`trative only and not in any way limiting. Other embodiments
`of the present invention will readily suggest themselves to
`such skilled persons.
`
`[0073] An object position detector is disclosed comprising
`a touch (or proximity) sensor (or touch pad or touch screen
`or tablet), such as a capacitive, resistive, or inductive sensor
`designed to sense motions along a substantially closed loop,
`and referred to herein as a closed~loop sensor. This closed—
`loop sensor can be used to enhance the user interface of an
`information-processing device. A loop area on a closed-loop
`sensor can be defined by a tactile guide. Preferably,
`the
`closed-loop sensor is defined by a physical constraint. The
`position of an input object (or finger or pointer or pen or
`stylus or implement) is measured along this loop. When the
`input object moves along this loop, a signal is generated that
`Causes an action at the host device. For example, when the
`input object moves in the clockwise direction along this
`loop, a signal is generated that can cause the data, menu
`option, three dimensional model, or value of a setting to
`traverse in a particular direction; and when the input object
`moves in the counter-clockwise direction, a signal is gen-
`erated that can cause traversal in an opposite direction. This
`looping motion of the input object within the loop area need
`only be partially along the loop, or if the looping motion
`completes one or more loops, be approximate and notional.
`A strict loop can imply that the input object would eventu-
`ally return to exactly the same position on the sensor at some
`point. However, the sensor may report the input object’s
`position with greater accuracy than the input object can
`actually repeatably indicate a position. Ilence, enabling the
`sensor to accept a close approximation to a loop as a
`completed loop is desirable.
`
`[0074] Aelosed-loop sensor can be physically designed or
`electrically laid out in such a way as to naturally report in
`only one coordinate. This single coordinate design, which
`will be referred to as “one—dimensional” within this doetb
`
`the closed—loop sensor
`in that
`is one—dimensional
`ment,
`inherently outputs information only in one variable;
`the
`closed-loop sensor itself may physically span two or more
`dimensions. For example, a closed-loop sensor can consist
`of a loop of capacitive electrodes arranged along the perim-
`eter of a closed loop of any shape herein described. The
`absolute position of the input object on a one-dimensional
`closed-loop sensor can be reported in a single coordinate,
`such as an angular (0) coordinate, and the relative positions
`(or motions) of the input object can he reported in the same
`(such as angular) units as well.
`
`[0075] The operation of the present invention with a host
`device is illustrated in the block diagram of FIG. 1. Asignal
`is generated at the closedvloop sensor 10 and is then decoded
`by the closed-loop path decoder 12. A message is generated
`by the message generator 14 and the message is transmitted
`to the host device 16. The host device 16 then interprets the
`message and causes the appropriate action on a display (not
`shown).
`
`[0076] The closed-loop sensor (or several closed-loop
`sensors) can be disposed in an)r location that is convenient
`for its use with a host device, and optional other input
`devices. A host system can be a computer. a
`laptop or
`handheld computer, a keyboard, a pointing device, an input
`device, a game device, an audio or video system, a thermo-
`stat, a knob or dial, a telephone, a cellular telephone, or any
`other similar device. For example, the closed-loop sensor
`can be positioned on a laptop near the keyboard as illustrated
`in FIG. 2. The base 20 of the laptop is illustrated having a
`keyboard 22,
`a
`touch pad (or
`touch screen) 24, and a
`closed-loop sensor 26. Alternative positions include posi-
`tioning the closed-loop sensor on or connecting it
`to a
`conventional computer or keyboard. FIG. 3 illustrates the
`closed-loop sensor 26 disposed on a conventional pointing
`device 28. Conventional pointing device 28 may have other
`features, such as left click or right click buttons, which are
`not shown.
`
`[0077] The closed-loop sensor of the present invention can
`also be implemented as a stand-alone device, or as a separate
`device to be used with another pointing input device such as
`a touch pad or a pointing stick. The closed-loop sensor ofthe
`present invention can either use its own resources, such as
`a processor and sensors, or share its resources with another
`device. The closed-loop sensor can be a capacitive, resistive,
`or inductive touch or proximity (pen or stylus) sensor. A
`capacitive sensor is preferred, and is illustrated herein.
`
`[0078] The closed-loop sensor can be implemented as a
`stand-alone sensor, which can then he used as a replacement
`for one or more knobs, sliders, or switches on any piece of
`electronic equipment. In some cases, it might be desirable to
`provide visual feedback indicating the “current" setting of
`the virtual knob, such as a ring of light emitting diodes
`(LEDs) surrounding the closed-loop region. An Etch-a-
`SketchT'“ type of electronic toy can be implemented using a
`single position detector with two closed-loop sensors or two
`position detectors with one closed~loop sensor each. Many
`other toys and consumer appliances currently have knobs
`used in similar ways that can benefit from the present
`invention.
`
`[0079] The closed-loop sensor can have electrodes (or
`sensor pads) that are of various shapes and designs (e.g., a
`simple wedge or pie-shape, a lightning—bolt or zigzag
`design, triangles, outward spirals, or the like} configured in
`a Closed-loop path. A Closed-loop sensor 30 having wedge-
`shaped electrodes is illustrated in FIG. 4, while a closed-
`loop sensor 34 having lightning-bolt-shaped electrodes is
`illustrated in FIG. 5. The sensor pattern can be designed so
`that it can have continuous interpolation between the elec-
`trodes. Thc sensor pattern can also be designed so that the
`electrodes interleave between each other to help spread the
`user’s input signal over several electrodes.
`
`[0080] FIG. 4 illustrates the wedge- (or pie-) shaped
`electrodes in a closed-loop capacitive sensor 30. When an
`
`22
`
`22
`
`

`

`US 2004/0252109 A1
`
`Dec. 16, 2004
`
`input object (or finger or pointer or stylus or pen or imple-
`ment) is over first electrode 31, only the first electrode 31
`senses the largest change in capacitance. As the input object
`moves clockwise toward electrodes 32 and 33, the signal
`registered by first electrode 31 gradually decreases as the
`signal registered by the second electrode 32 increases; as the
`input object continues to move further clockwise toward
`third electrode 33, the lirst electrode 31 signal drops 01? and
`the third electrode 33 starts picking up the input object, and
`so on. By processing the electrode signals in largely the
`same way as for a standard linear sensor, and taking into
`account
`that
`there is no true beginning or end to the
`closed-loop sensor, the object position detector having the
`wedge sensor can interpolate the input object’s position
`accurately.
`[0081] FIG. 5 illustrates the lightning-bolt-shaped elec-
`trodes in a closed—loop sensor 34. The lightningwbolt design
`helps spread out the signal associated with an input object
`across many electrodes by interleaving adjacent electrodes.
`The signals on a closed-loop sensor with lightning-bolt
`shaped electrodes are spread out in such a way that the
`electrode closest to the actual position of the input object has
`the largest signal. the nearby electrodes have the next largest
`signal, and the farther electrodes have small or negligible
`signals. However, comparing a lighting—bolt sensor with a
`wedge sensor with a similar size and number of electrodes,
`an input object on the lightning-bolt sensor will typically
`couple to more electrodes than in the wedge sensor. This
`means that the lighting-bolt sensor will have more informa-
`tion about the input object’s position than a wedge sensor,
`and this elfect helps increase sensor resolution and accuracy
`in sensing the input object’s position. For best results, the
`electrodes of the lightning bolt sensor need to be sufficiently
`jagged in shape such that the input object on the sensor will
`always cover more than one electrode. The interleaving
`nature of this electrode design means that the spacing from
`one electrode to the next can be larger than in the wedge
`sensor while still providing similar resolution and accuracy.
`The spacing from one electrode to the next with such an
`interdigitated electrode design may even be considerably
`larger than the expected input object.
`[0082] Another example is a closed-loop sensor 35 having
`triangle-shaped electrodes, as illustrated in FIG. 6. In this
`case, the odd-numbered triangle-shaped electrodes (eg. 37,
`39) are wider toward the outer edge of the closed-loop area
`and narrower toward the inner edge of the closed~loop area,
`while the even—numbered triangle—shaped electrodes (cg.
`36, 38) have the opposite positioning. To compute the input
`object's a