US 7,631,811 B1
`(10) Patent No.:
`a2) United States Patent
`Brown
`(45) Date of Patent:
`Dec. 15, 2009
`
`
`US007631811B1
`
`(54) OPTICAL HEADSET USER INTERFACE
`
`(75)
`
`Inventor: William Owen Brown, Santa Cruz, CA
`(US)
`
`(73) Assignee: Plantronics, Inc., Santa Cruz, CA (US)
`
`(*) Notice:
`
`Subject to any disclaimer, the term ofthis
`patent is extended or adjusted under 35
`U.S.C. 154(b) by 103 days.
`
`(21) Appl. No.: 11/906,803
`
`(22)
`
`Filed:
`
`Oct. 4, 2007
`
`(51)
`
`Int. Cl.
`(2006.01)
`GO6K 7/14
`(52) U.S.Coe 235/454; 379/428 .02; 455/73
`(58) Field of Classification Search ................. 235/454;
`.
`3791428.02
`See applicationfile for complete search history.
`References Cited
`
`(56)
`
`2007/0274530 Al* 11/2007 Builetal.0... 381/74
`2008/0130910 Al
`6/2008 Jobling et al.
`2008/0284734 AL* 11/2008 Visser... eee 345/166
`OTHER PUBLICATIONS
`
`Gregory, Peter; Doria, Tom; Stegh, Chris; Su, Jim; SIP Communica-
`tions For Dummies, Avaya Custom Edition, 2006, Wiley Publishing,
`Inc., Hoboken, NJ, USA.
`* cited by examiner
`.
`.
`.
`Primary Examiner—Daniel A Hess
`Assistant Examiner—Laura Gudorf
`(74) Attorney, Agent, or Firm—Intellectual Property Law
`Office of Thomas Chuang
`
`ABSTRACT
`(57)
`A headset includes a finger pad on an exterior ofthe headset
`on which a finger of a headset weareris placed. The headset
`includes an optical line scanner which scans the finger pad
`and outputs a series of successive imagesofthe finger placed
`on the finger pad. A headset processor processesthe output of
`the optical line scanner to detect relative motion ofthe finger
`on the finger pad or detect tapping of the finger on the finger
`pad.
`
`U.S. PATENT DOCUMENTS
`6,980,673 B2* 12/2005 Funahashi .......0..00.... 382/124
`2001/0017934 A1l*
`8/2001 Paloniemiet al.
`........... 382/107
`
`20 Claims, 5 Drawing Sheets
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`1
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`APPLE 1008
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`1
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`APPLE 1008
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`U.S. Patent
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`US 7,631,811 B1
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`Dec. 15, 2009
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`Sheet 1 of 5
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`FIG. 1
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`2
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`U.S. Patent
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`Dec. 15, 2009
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`Sheet 2 of 5
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`US 7,631,811 B1
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`2 oS
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`Processor
`10
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`50
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`Power Source
`—_ —
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`Memory
`= NO
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`Microphone
`—_ BAS
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`Speaker
`= Oo)
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`User Interface 18
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`Line
`Scanner 20
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`Light Source 22
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`Input Keys 6
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`-
`Optical Sensor 26
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`Finger Pad 4
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`FIG. 2
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`3
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`U.S. Patent
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`Dec. 15, 2009
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`Sheet 3 of 5
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`US 7,631,811 B1
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`FIG. 3
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`4
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`U.S. Patent
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`Dec. 15, 2009
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`Sheet 4 of 5
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`US 7,631,811 B1
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`Line Scannerfor Scrolling
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`FIG. 4A
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`FIG. 4B
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`32
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`eeee
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`ANS
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`FIG. 4C
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`FIG. 4D
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`U.S. Patent
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`Dec. 15, 2009
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`Sheet 5 of 5
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`US 7,631,811 B1
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`Line Scannerfor Selecting
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`——
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`Figure 5A
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`4
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`4
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`Figure 5B
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`4
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`So
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`Figure 5C
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`6
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`6
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`2
`This invention relates generally to the field of headset user
`interfaces andspecifically to the field ofheadset userinterface
`input mechanisms. In one example, this description describes
`a method and apparatus for a headset with an optical line
`scamneronalightweight headset, wherethe opticalline scan-
`Recent developmentsin the telecommunications industries
`ner detects finger movements, such as tapping, sliding for-
`have produced telecommunications devices with increased
`ward and sliding backward to be translated into various
`capabilities. As a result, the complexity of interacting with
`inputs, such as volume up and down, menuscrolling, and
`these devices has increased. Headsets are now capable of
`other headset user interface options knownintheart.
`doing more than being simple peripherals to legacy phones.
`For example, the headsets may control navigation through
`As a user moveshis or her finger moves across the line
`menusorfiles.
`scamner, relative motionofthe fingerprints ridges and valleys
`However, headset form factors do not lend themselves well
`are scanned. In the same mannerthat an optical mouse inter-
`to traditional user interface technologies like keypads and
`prets the changing images to detect movementof the mouse,
`displays which are suited for complex user man-machine
`motion ofthe userfinger is determined. However,for a head-
`interface interactions. For example, the available space on the
`set user interface, only one axis is neededfor scrolling, allow-
`headset housingis limited. In the priorart, headset userinter-
`ing the possibility of using a line scanner. For tapping, an
`faces typically consist of a small number of multifunction
`algorithm is used to determine the amount of light being
`buttons and a multifunction visual indicator. This limited user
`received by the optoelectronic sensor. In a further example, to
`interface makes access to more complex features and capa-
`reducefalse triggers, such as dueto hair falling in front ofthe
`bilities difficult and non-intuitive, particularly whenthe head-
`sensor, secondary mechanismsare used such as overlaying a
`set is being worn. Visualindicators have limited use while the
`transparent touch sensor such as a capacitance sensor on the
`headset is being worn. Multifunction buttons are non-intui-
`line scanner pad.
`tive and awkwardto use.
`In one example of the invention, a headset includes a
`microphone,a speaker, and a finger pad on an exterior of the
`headset on which a finger of a headset wearer is placed. The
`headset includes an optical line scanner which scansthe fin-
`ger pad and outputs a series of successive imagesofthe finger
`placed on the finger pad. A headset processor processes the
`output of the optical line scanner to detect relative motion of
`the finger on the finger pad or detect tapping of the finger on
`the finger pad. The optical line scanner may include a light
`source, an optical guide for forming a line of light from the
`light source, an imaging sensor, and a lens for directing the
`line of light reflected from the finger pad onto the imaging
`sensor.
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`US 7,631,811 B1
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`1
`OPTICAL HEADSET USER INTERFACE
`
`BACKGROUND OF THE INVENTION
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`10
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`they offer
`As headsets become more “intelligent”,
`advanced features and functionality. With increased features
`and functionality, these headsets require more complex user
`interfaces. However, the limited physical size of headset
`housings makes it desirable to minimize the number of or
`required size of the headset user interface mechanisms.
`As a result, there is a need for improved methods and
`apparatuses for headset user interface input mechanisms.
`
`BRIEF DESCRIPTION OF THE DRAWINGS
`
`The present invention will be readily understood by the
`following detailed description in conjunction with the accom-
`panying drawings, wherein like reference numerals designate
`like structural elements.
`
`FIG.1 illustrates a headset capable ofreceiving user inputs
`utilizing an optical line scanner.
`FIG.2 illustrates a simplified block diagram of the com-
`ponents of the headset shown in FIG.1.
`FIG. 3 illustrates a side view of a headset showing the
`internal arrangementofa line scanner system.
`FIGS. 4A-4Dillustrate sample operation of a line scanner
`to detect user input scrolling as the user “wipes”his finger.
`FIGS. 5A-5Cillustrate sample operation of a line scanner
`to detect user input tapping.
`
`In one example ofthe invention, a headset includesa finger
`receiving means for placement ofa userfinger, and an optical
`line scanning means for scanning the finger receiving means
`on a headset housing exterior and providing an output of
`successive imagesofthe finger receiving means. The process-
`ing meansprocesses the output of successive images on the
`finger pad to determine a relative movementofa user finger
`across the finger pad or to determine a tapping of the user
`finger on the finger pad. The processing means modifies a
`headset control operation responsive to the relative move-
`mentofthe user finger or the tapping.
`In one example of the invention, a method for receiving
`user inputat a headset includes providing a transparentfinger
`pad ona headset housing for receiving a userfinger, providing
`an optical line scanner disposed within the headset housing,
`and scanning the transparent finger pad with the optical line
`scamnerto output a series of successive images. The method
`Methods and apparatuses for a headset user interface is
`further includes processing the successive images to deter-
`disclosed. The following description is presented to enable
`mine a relative movementof a user finger across the finger
`any person skilled in the art to make and use the invention.
`pad, and modifying a headset control operation responsive to
`Descriptions of specific embodiments and applications are
`the relative movementofthe userfinger.
`provided only as examples and various modifications will be
`In one example ofthe invention, a headset includesa finger
`readily apparentto those skilled in the art. The general prin-
`receiving means for placement ofa userfinger, and an optical
`ciples defined herein may be applied to other embodiments
`scanning means for scanning the finger receiving means on a
`and applications without departing from the spirit and scope
`headset housing exterior and providing a sequenceofelectri-
`ofthe invention. Thus, the present invention is to be accorded
`cal signals associated with successive line scan imagesof the
`the widest scope encompassing numerousalternatives, modi-
`finger receiving means. The headset further includes a pro-
`fications and equivalents consistent with the principles and
`cessing means for processing the sequenceofelectrical sig-
`features disclosed herein. For purposeofclarity, details relat-
`65
`nals to determinearelative bi-directional movementofa user
`ing to technical material that is known in the technicalfields
`related to the invention have not been described in detail so as
`finger across the finger pad along a single axis or determine a
`tapping of the user finger on the finger pad. The processing
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`DESCRIPTION OF SPECIFIC EMBODIMENTS
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`not to unnecessarily obscure the present invention.
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`US 7,631,811 B1
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`In one example the line scanner 20 continuously monitors
`means modifies a headset control operation responsive to the
`finger pad 4 to identify whethera user has placed a finger on
`relative movementof the user finger or the tapping.
`finger pad 4 to perform an input action. User interface 18
`In one example of the invention, a method for receiving
`allows for manual communication between the headset user
`user inputat a headset includes providing a transparentfinger
`and the headset. User interface 18 may also include, for
`pad ona headset housingfor receiving a user finger, providing
`example, an audio and/or visual interface such that an audio
`an optical line scanner disposed within the headset housing,
`prompt maybeprovidedto the user’s ear and/or an LED may
`and scanning the transparent finger pad with the optical line
`belit. For example, the prompt may inform the user to place
`scanner to output a sequenceofelectrical signals associated
`his or her finger on the finger pad to perform a fingerprint
`with successive line scan images. The sequenceofelectrical
`scan. Although illustrated in FIG. 2 as separate from line
`signals is processed to determine a relative movement of a
`scanner 20, finger pad 4 may also be considered to be a
`user finger across the finger pad. The headset control opera-
`componentof line scanner 20.
`tion is modified responsive to the relative movement of the
`FIG.3 illustrates a side view of the headset 2 showing the
`userfinger.
`internal arrangementofthe line scanner system. The housing
`FIG. 1 illustrates a headset 2 capable of receiving user
`body ofheadset 2 includes a finger pad 4. Headset 2 may also
`inputs utilizing an optical line scanner. Headset 2 includes a
`include one or more user interface buttons or keys 6 which the
`narrow finger pad 4 serving as a scanning surface on which a
`user may depress.
`user finger is placed and scanned by the user “wiping”his
`The finger pad 4 is optically transparent, allowing light
`finger across the scanning surface. During optical scanning,
`from a light source 22 disposed within the headset housing to
`the user slides his or her finger across the scanning surface,
`20
`exit the headset. For example, finger pad4is a planar surface
`wherebythe line scanner imagesthefinger line byline asit is
`composedofglass or plastic. After light from the light source
`slid across the scanning surface.
`22 is reflected off the finger pad 4, it re-enters the headset
`FIG.2 illustrates a simplified block diagram of the com-
`housing and is focused by a lens 24 on an optical sensor 26.
`ponents of the headset 2 shown in FIG. 1. The headset 2
`For example, optical sensor 26 is a motion sensor integrated
`includes a processor 10 operably coupled via a bus 50 to a
`circuit (IC) having an array ofphotodetectors for capturing an
`memory 12, a microphone 14, power source 11, and user
`image. Optical sensor 26 converts light information into an
`interface 18. User interface 18 includesa line scanner 20 and,
`electrical signal and transmits the signal to a system image
`optionally, one or more input buttons or keys 6. In one
`processing unit. Lens 24 and optical motion sensor 26 are
`example, line scanner 20 includes a light source 22, lens 24,
`disposed within the headset 2. An optical guide may be
`and optical sensor 26. Optical sensor 26 is, for example, a
`arranged to convert light from light source 22 into a line-
`charge coupled device (CCD) such as a CMOSsquare pixel
`shaped light to illuminate a fingerprint in a line-shape. In a
`array. The CCD is an array of light sensitive diodes which
`further example, a scanning component may sweep a beam
`generate an electrical signal in responseto light which hits a
`spot oflight across the finger pad 4 and the optical sensor may
`particular pixel. Line scanner 20 mayalso include a processor
`be a single element.
`for processing scan data. Alternatively, line scanner 20 may
`Thelight reflected off the finger pad 4 forms an imageof a
`utilize processor 10 to process scan data. Line scanner 20 may
`user finger placed on the finger pad 4 on optical sensor 26.
`also include memory separate from memory 12 for storing
`This image is captured by optical sensor 26. For example,
`scan data or firmware/software executable to operate line
`optical sensor 26 has a plurality of line-shaped photoelectric
`scanner 20 and process scan data. The firmware/software may
`converting elements. Successive imagesofa finger placed on
`include a user input
`identifier application for analyzing
`the finger pad 4 are then comparedby a processor. The pro-
`scanned finger motion data to determine user input at the
`cessor may be integrated with the optical sensor 26 or may be
`finger pad 4. Alternatively,
`line scanner 20 may utilize
`a separate processor such as the headset processor 10. The
`memory 12 for such purposes. The line scanner 20 is properly
`successive images are compared to determine the forward or
`aligned and integrated with finger pad 4 within the headset
`backward motion ofthe user finger across finger pad 4. The
`housing. Ina further example, line scanner 20 is replaced with
`successive images are also compared to determine whether
`an alternative optical scanner. Examples of optical scanners
`the useris “tapping”or “double tapping”the finger pad 4, 1.e.,
`include, without limitation, image sensors, planar scanners,
`quickly placing his fingertip on finger pad 4 and then remov-
`CMOSsensors, contact image sensors, or other optical sys-
`ing it. Depending on the current operational state ofthe head-
`tems such as used by optical mouse devices.
`set, the forward or backward motion is translated to a pre-
`Memory 12 mayinclude a variety of memories, and in one
`defined user input, such as scrolling through a menu or
`example includes SDRM, ROM,flash memory, or a combi-
`volumeincrease or decrease. User tapping or double tapping
`nation thereof. Memory 12 may further include separate
`is translated, for example, to a user selected command.
`memory structures or a single integrated memory structure. In
`The directional motion of a finger on finger pad 4 along a
`one example, memory 12 may be usedto store passwords,
`single axis (e.g., X or Y) or the presenceofa finger on finger
`network and telecommunications programs, and/or an oper-
`pad 4 is detected optically by optical sensor 26 by directly
`ating system (OS).
`imaging, as an array of pixels, the various particular ridges
`Processor 10, using executable code and applications
`and valleys of the user fingerprint placed on the finger pad 4.
`stored in memory, performs the necessary functions associ-
`The particular features of the fingerprint are illuminated by
`ated with headset operation described herein. Processor 10
`the light source 22. The use of optical sensors to detect direc-
`allows for processing data,
`in particular managing data
`tion and degree ofmovement along an X-Y coordinate system
`between user interface 18 and operation of headset 2 func-
`is described in U.S. Pat. No. 6,233,368 issued May 15, 2001,
`tions. In one example, processor 10 is a high performance,
`entitled “CMOSDigital Optical Navigation Chip”, which is
`highly integrated, and highly flexible system-on-chip (SOC),
`hereby incorporated by referencefor all purposes.
`including signal processing functionality such as echo can-
`The motion ofa finger on finger pad 4 is detected by optical
`cellation/reduction and gain control in another example. Pro-
`sensor 26 by comparing a newly captured image with a pre-
`cessor 10 may include a variety of processors (e.g., digital
`viously captured imageto ascertain the direction and amount
`signal processors), with conventional CPUsbeing applicable.
`ofmovement. The newly captured imageand previously cap-
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`US 7,631,811 B1
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`5
`tured images may be stored in memory on the optical sensor
`26 or stored in headset memory 12. For example, referring to
`FIGS. 4A-4C, sample operation of line scanner 20 to detect
`user input scrolling as the user “wipes”his finger in a direc-
`tion 30 is illustrated. FIG. 4A illustrates a fingerprint 28
`corresponding to a userfinger placed on finger pad 4. Refer-
`ring to FIG. 4C, a fingerprint portion 32 scanned by line
`scanner 20 is captured. At an immediate point in time there-
`after as the user finger is wiped in direction 30, the fingerprint
`28 is at a secondposition onfinger pad 4, as shown in FIG. 4B.
`As a result, a different fingerprint portion 34 scanned by line
`scanner 20 is captured, as shown in FIG. FIG. 4D. The image
`of fingerprint portion 32 is comparedto the imageoffinger-
`print portion 34 to ascertain the direction of movementof the
`user finger across finger pad 4. For example, the ridges and
`valleys of the fingerprint line scans may be pattern matched
`and aligned to determine the direction of movement.
`For example, referring to FIGS. 5A-5C, sample operation
`of line scanner 20 to detect user input tappingis illustrated. In
`this example, line scanner 20 detects user tapping by deter-
`mining whether the user has placed his finger across finger
`pad 4 and removedit immediately thereafter. For example, at
`a first ttme shown in FIG. 5A,the user finger pad 4 does not
`have a finger placed uponit. At a second time shownin FIG.
`5B, the user has placedhis finger upon finger pad 4, which is
`scanned by line scanner 20. At third time illustrated in FIG.
`5C, the finger pad 4 is once again clear as the user has
`removed his finger. In one example, the quantity of light
`detected by the sensoris used to determine a tap. In a further
`example, a time period on which the user finger is placed on
`finger pad 4 to indicate a user tap is empirically determined.
`Double tapping is detected, for example, by detecting user
`tapping twice within a predefined time period.
`The information developed by optical sensor 26 regarding
`the motion ofthe user finger on the finger pad 4 is relayed to
`the headset processor 10, which translates the information to
`correspond to user input actions at the headset. The headset
`processor 10 then implements the desired input action. For
`example, such desired input actions may include volume
`control, power control, call answer, call
`terminate,
`item
`select, next item, and previous item,or other actions typically
`performedat a headset device.
`Ina further example, line scanner 20 is used to authenticate
`the identity of the headset user by scanning the fingerprint of
`the user and comparing it to a previously stored authorized
`fingerprint. During optical scanning,the user slides his or her
`finger across the scanning surface, whereby the line scanner
`imagesthe finger line by lineasit is slid across the scanning
`surface. In this manner, the fingerprint of the user is gener-
`ated. In this example, the headset memory includesprevi-
`ously storedfingerprint data correspondingto validated users,
`a feature identifier application for analyzing scanned finger-
`print scan data, and a fingerprint match application for com-
`paring the analyzed scanned fingerprint scan data to previ-
`ously stored fingerprint data. In one example, headset user
`authentication is required prior to allowingthe userto operate
`the headset. In this example, the line scanner 20 serves the
`dual function of being a user interface input device and an
`authentication device.
`
`The various examples described above are provided by
`wayof illustration only and should not be construed to limit
`the invention. Based on the above discussion andillustrations,
`those skilled in the art will readily recognize that various
`modifications and changes may be madeto the present inven-
`tion without strictly following the exemplary embodiments
`and applications
`illustrated and described herein. For
`example, the methods and systems described herein may be
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`applied to other body worn devices in addition to headsets.
`Furthermore, the functionality associated with any blocks
`described above may be centralized or distributed. It is also
`understood that one or more blocks of the headset may be
`performed by hardware, firmware or software, or some com-
`binations thereof. Such modifications and changes do not
`depart from the true spirit and scopeof the present invention
`that is set forth in the following claims.
`While the exemplary embodiments ofthe present invention
`are described andillustrated herein, it will be appreciated that
`they are merely illustrative and that modifications can be
`made to these embodiments without departing from the spirit
`and scopeof the invention. Thus, the scopeof the invention is
`intended to be defined only in terms ofthe following claims as
`may be amended, with each claim being expressly incorpo-
`rated into this Description of Specific Embodiments as an
`embodimentofthe invention.
`
`Whatis claimedis:
`
`1. A headset comprising:
`a microphone;
`a speaker;
`a finger pad on an exterior of the headset on which a finger
`of a headset wearer is placed;
`an optical line scanner, wherein the optical line scanner
`scans the finger pad and outputs a series of successive
`imagesofthe finger placed on the finger pad; and
`a processor, wherein the processor processesthe series of
`successive imagesto detect relative motion of the finger
`on the finger pad or detect tapping of the finger on the
`finger pad.
`2. The headset of claim 1, wherein the optical line scanner
`comprises:
`a light source;
`an optical guide for forminga line of light from the light
`source an imaging sensor; and
`alens for directing the line of light reflected from the finger
`pad onto the imaging sensor.
`3. The headset of claim 2, wherein the light source com-
`prises a light emitting diode.
`4. The headset of claim 2, wherein the imaging sensor
`comprises an integrated circuit sensor.
`5. The headset of claim 1, wherein the optical line scanner
`detects relative motion of the finger on the finger pad along a
`single axis.
`6. The headset of claim 1, wherein the finger pad comprises
`a glass planar surface.
`7. A headset comprising:
`a finger receiving meansfor placementofa userfinger;
`an optical line scanning means for scanning the finger
`receiving means on a headset housing exterior and pro-
`viding an output of successive images of the finger
`receiving means;
`a capacitive sensing means overlaid on thefinger receiving
`meansfor sensing placementof a userfinger to detect a
`false trigger of the optical line scanning means; and
`a processing meansfor processing the output of successive
`images of the finger receiving means to determine a
`relative movement of a user finger across the finger
`receiving meansor determine a tapping ofthe user finger
`on the finger receiving means, wherein the processing
`means modifies a headset control operation responsive
`to the relative movementofthe user finger or the tap-
`ping;
`a first transducer meansfor receiving a user speech signal;
`and
`
`a second transducer means for outputting an audiosignal.
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`US 7,631,811 B1
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`8. The headset of claim 7, wherein the headset control
`mentof a user finger across the finger receiving means
`along a single axis or determine a tapping of the user
`operation comprises one or moreselected from the following
`finger on the finger receiving means, wherein the pro-
`group: volume control, powercontrol, call answer, call ter-
`cessing means modifies a headset control operation
`minate, item select, next item, and previous item.
`responsiveto therelative bi-directional movementofthe
`9. A methodfor receiving user input at a headset compris-
`user finger or the tapping;
`ing:
`a first transducer means for receiving user speech; and
`providing a transparentfinger pad on a headset housing for
`a second transducer means for outputting an audiosignal.
`receiving a user finger;
`15. The headset of claim 14, wherein the headset control
`providing an optical line scanner disposed within the head-
`operation comprises one or moreselected from the following
`set housing;
`group: volume control, power control, call answer, call ter-
`scanning the transparent finger pad with the optical line
`minate, item select, next item, and previous item.
`scamnerto output a series of successive images;
`16. Amethodfor receiving user inputat a headset compris-
`processing the series of successive images to determine a
`ing:
`relative movementof a userfinger across the transparent
`providing a transparentfinger pad on a headset housing for
`finger pad; and
`receiving a user finger;
`modifying a headset control operation responsive to the
`providing an optical line scanner disposed within the head-
`relative movementof the user finger.
`set housing;
`10. The method of claim 9, wherein processing the succes-
`scanning the transparent finger pad with the optical line
`sive images to determine a relative movementofa user finger
`scamnerto output a sequenceofelectrical signals asso-
`across the finger pad comprising determining whether the
`ciated with successive line scan images;
`user finger is moving inafirst direction along an axis or ina
`processing the sequenceofelectrical signals to determine a
`second direction oppositethe first direction along the axis.
`relative movementofa user finger across the transparent
`11. The methodof claim 9, further comprising processing
`finger pad; and
`the successive images to determinea tap ofthe userfinger on
`modifying a headset control operation responsive to the
`the finger pad.
`relative movementofthe userfinger.
`12. The method of claim 11, wherein processing the suc-
`17. The method of claim 16, wherein processing the
`cessive images to determine a tap of the user finger on the
`sequence of electrical signals comprises pattern matching
`finger pad comprises measuring a quantity oflight received at
`fingerprint ridges and valleys.
`the optical line scanner.
`18. The method of claim 16, wherein processing the
`13. The method of claim 9, wherein processing the succes-
`sequence ofelectrical signals to determine a relative move-
`sive images comprises identifying and comparing fingerprint
`mentofauserfinger across the finger pad comprising deter-
`ridges andvalleys.
`mining whetherthe user finger is moving inafirst direction
`14. A headset comprising:
`along an axis or in a seconddirection oppositethefirst direc-
`a finger receiving means for placementofa user finger;
`tion along the axis.
`an optical scanning meansfor scanningthe finger receiving
`19. The methodof claim 16, further comprising processing
`means on a headset housing exterior and providing a
`the sequence ofelectrical signals to determine a tap ofthe user
`sequenceof electrical signals associated with successive
`finger on the finger pad.
`line scan imagesof the finger receiving means;
`20. The method of claim 19, wherein processing the
`acapacitive sensing meansoverlaid on the finger receiving
`sequence ofelectrical signals to determine a tap of the user
`meansfor sensing placementof a userfinger to detect a
`finger on the finger pad comprises measuring a quantity of
`false trigger of the optical line scanning means; and
`light received at the optical line scanner.
`a processing meansfor processing the sequenceofelectri-
`*
`*
`*
`*
`*
`cal signals to determinea relative bi-directional move-
`
`20
`
`35
`
`10
`
`10
`
`