Power efficient stylus for an electronic device

Systems, methods, and computer-readable media for enabling a power efficient stylus for an electronic device are provided.

FIELD

This generally relates to a stylus and, more particularly, to a power efficient stylus for an electronic device, as well as to systems, methods, and computer-readable media for use thereof.

BACKGROUND

Some systems may include an electronic device with a sensor assembly to facilitate a user's interaction with the device, as well as a stylus for providing a user with a more precise instrument than the user's fingers for interacting with the sensor assembly, such as for generating a graphical object on a display of the electronic device. However, existing systems often require an active stylus that uses power intensive electronics or a passive stylus that is difficult to distinguish from a user's finger.

SUMMARY

Systems, methods, and computer-readable media for enabling a power efficient stylus for an electronic device are provided.

As an example, a stylus for use with an electronic device that includes an input component with an input surface may be provided, the stylus including a housing and stylus circuitry at least partially positioned within the housing, wherein the stylus circuitry includes body circuitry, a front tip interface component, and front tip stylus circuitry positioned between and electrically coupled to each one of the body circuitry and the front tip interface component, the front tip stylus circuitry includes non-linear circuitry that is operative to provide a non-linear load between the body circuitry and the front tip interface component when the stylus circuitry is stimulated by an external stimulation, and the non-linear load is operative to provide a stylus electric field that is detectable by the electronic device when the front tip interface component of the stylus is positioned adjacent the input surface of the input component of the electronic device.

As another example, a stylus for use with an electronic device that includes an input component with an input surface may be provided, the stylus including a tip interface component and tip stylus circuitry electrically coupled to the tip interface component, wherein the stylus is operative to drive a current back and forth through the tip stylus circuitry when the tip stylus circuitry is stimulated by an electrical signal provided by the input component of the electronic device, and the driven current is operative to provide a modulated version of the electrical signal that is detectable by the electronic device when the tip interface component of the stylus is positioned adjacent the input surface of the input component of the electronic device.

As yet another example, a method for using a stylus including non-linear circuitry at an input component of an electronic device may be provided, the method including transmitting an electrical signal from transmitter circuitry of the input component of the electronic device, stimulating the non-linear circuitry of the stylus with the transmitted electrical signal, providing a non-linear load at the stylus based on the stimulating, and creating a harmonic of the transmitted electrical signal at the input component of the electronic device based on the provided non-linear load.

As yet another example, a stylus for use with an electronic device that includes an input component with an input surface may be provided, the stylus including a housing and stylus circuitry at least partially positioned within the housing, wherein the stylus circuitry includes body circuitry, a tip interface component, and tip stylus circuitry, the tip stylus circuitry includes switch circuitry that is operative to alternate according to a pattern between a first state in which the body circuitry and the tip interface component are electrically coupled and a second state in which the body circuitry and the tip interface component are not electrically coupled, and the alternation of the switch circuitry is operative to provide a modulated capacitance at the tip interface component that is detectable by the electronic device when the tip interface component of the stylus is positioned adjacent the input surface of the input component of the electronic device.

As yet another example, a stylus for use with an electronic device that includes an input component with an input surface may be provided, the stylus including a tip interface component and tip stylus circuitry electrically coupled to the tip interface component, wherein the tip stylus circuitry is operative to change a load of the stylus according to a pattern when the tip stylus circuitry is exposed to an electrical signal provided by the input component of the electronic device, and the changed load is operative to provide a modulated version of the electrical signal that is detectable by the electronic device when the tip interface component of the stylus is positioned adjacent the input surface of the input component of the electronic device.

As yet another example, a method for using a stylus including switching circuitry at an input component of an electronic device may be provided, the method including transmitting an electrical signal from transmitter circuitry of the input component of the electronic device, concurrently with the transmitting, switching the switching circuitry according to a pattern, and, based on the switching, modulating the transmitted electrical signal according to the pattern.

As yet another example, a method for detecting an accessory on an input surface of an input component of an electronic device that includes a matrix of a plurality of transmit electrodes and a plurality of receive electrodes, may be provided, the method including transmitting a transmit signal on each transmit electrode of at least a subset of the plurality of transmit electrodes, sensing a receive signal on each receive electrode of at least a subset of the plurality of receive electrodes, extracting, from each sensed receive signal, data indicative of a non-linear aspect of the transmit signal, and estimating a position of the accessory on the input surface based on the extracted data.

As yet another example, an electronic device may be provided that includes an input component including an input surface and a matrix underneath the input surface including a plurality of transmit electrodes and a plurality of receive electrodes, and processing circuitry configured to transmit a transmit signal on each transmit electrode of at least a subset of the plurality of transmit electrodes, sense a receive signal on each receive electrode of at least a subset of the plurality of receive electrodes, extract, from each sensed receive signal, data indicative of a non-linear aspect of the transmit signal, and estimate a position of an accessory on the input surface based on the extracted data.

As yet another example, an electronic device input component may be provided that includes an input surface, a plurality of electrodes, and processing circuitry configured to provide a transmit waveform on each electrode of at least a subset of the plurality of electrodes, detect a receive waveform on each electrode of at least another subset of the plurality of electrodes, extract, from each detected receive waveform, data indicative of asymmetric distortion of the transmit waveform, and determine a location of an accessory on the input surface based on the extracted data.

As yet another example, an electronic device may be provided that includes an input component including an input surface and a matrix underneath the input surface including a plurality of transmit electrodes and a plurality of receive electrodes, and processing circuitry configured to transmit transmit signals on transmit electrodes of at least a subset of the plurality of transmit electrodes, sense a receive signal on each receive electrode of at least a subset of the plurality of receive electrodes, extract, from the sensed receive signals, data indicative of a non-linear response to the transmit signals, and estimate a position of an accessory on the input surface based on the extracted data.

As yet another example, an electronic device input component may be provided that includes an input surface, a plurality of electrodes, and processing circuitry configured to provide transmit waveforms on electrodes of at least a subset of the plurality of electrodes, detect a receive waveform on each electrode of at least another subset of the plurality of electrodes, extract, from the detected receive waveforms, data indicative of a non-linear response to the transmit waveforms, and determine a location of an accessory on the input surface based on the extracted data.

This Summary is provided only to summarize some example embodiments, so as to provide a basic understanding of some aspects of the subject matter described in this document. Accordingly, it will be appreciated that the features described in this Summary are only examples and should not be construed to narrow the scope or spirit of the subject matter described herein in any way. Unless otherwise stated, features described in the context of one example may be combined or used with features described in the context of one or more other examples. Other features, aspects, and advantages of the subject matter described herein will become apparent from the following Detailed Description, Figures, and Claims.

DETAILED DESCRIPTION

In the following detailed description, for purposes of explanation, numerous specific details are set forth to provide a thorough understanding of the various embodiments described herein. Those of ordinary skill in the art will realize that these various embodiments are illustrative only and are not intended to be limiting in any way. Other embodiments will readily suggest themselves to such skilled persons having the benefit of this disclosure.

In addition, for clarity purposes, not all of the routine features of the embodiments described herein are shown or described. One of ordinary skill in the art will readily appreciate that in the development of any such actual embodiment, numerous embodiment-specific decisions may be required to achieve specific design objectives. These design objectives will vary from one embodiment to another and from one developer to another. Moreover, it will be appreciated that such a development effort might be complex and time-consuming, but would nevertheless be a routine engineering undertaking for those of ordinary skill in the art having the benefit of this disclosure.

The present disclosure relates to one or more power efficient styli for interacting with a sensor assembly of an electronic device, such as for generating a graphical object on a display of the electronic device.

Systems, methods, and computer-readable media for enabling a power efficient stylus for an electronic device are provided and described with reference toFIGS. 1-10.

FIG. 1is a schematic view of an illustrative system1with an electronic device100and a stylus400. Stylus400(e.g., a marking tool, smart pen, smart brush, wand, chisel, user-manipulated electronic input device, hand-held input device, and the like, or any other suitable accessory, such as a glove) may be configured to provide input to electronic device100(e.g., a tablet computer, laptop computer, desktop computer, and the like). A system user may manipulate the orientation and position of stylus400relative to an input surface of electronic device100to convey information to electronic device100, such as, but not limited to, writing, sketching, scrolling, gaming, selecting user interface elements, moving user interface elements, and so on. In many embodiments, the input surface of electronic device100may be a multi-touch display screen. However, in other embodiments, the input surface of electronic device100may be a non-display input surface, such as, but not limited to, a trackpad or drawing tablet. The input surface may be a foldable or flexible surface or display. System1may be used to capture free-form user input from stylus400. For example, the user can slide, move, draw, or drag a tip of stylus400across the input surface of electronic device100, which, in response, may render a graphical object (e.g., a line) using a display positioned below the input surface. In such an example, the rendered graphical object may follow or otherwise correspond to the path of stylus400across the input surface of electronic device100. The thickness and/or shape and/or intensity and/or any other suitable rendered characteristic of the rendered graphical object may vary based, at least in part, on one, some, or each of various characteristics, including, but not limited to, a force or speed with which the user moves stylus400across the input surface, an angle of stylus400relative to the input surface (e.g., the inclination of stylus400relative to a plane of the input surface, a writing angle of stylus400relative to a horizontal writing line traversing the input surface, etc.), a variable setting of a variable input component of stylus400, which one of multiple tips of stylus400is interacting with the input surface, a variable setting of an application running on electronic device100(e.g., a virtual drawing space application), and/or a combination thereof. Collectively, stylus400and electronic device100may be referred to herein as a “user input” system1.

Broadly and generally, system1may be operative to determine and/or estimate one or more outputs of stylus400(and/or changes therein over time as a scalar or vector quantity), to interpret the user's manipulation thereof as input to electronic device100. For example, system1may be operative to estimate: the magnitude of force applied by a user's grip to stylus400(e.g., non-binary estimate of magnitude as a scalar or vector quantity); a magnitude (e.g., non-binary estimate of magnitude as a scalar or vector quantity) of force applied (e.g., force applied Fa) by stylus400to the input surface of electronic device100; the location at which or the area over which stylus400may touch or nearly touch the input surface of electronic device100; a polar angle of stylus400relative to a plane of the input surface (e.g., inclination of stylus400(e.g., a polar angle118(θ) (e.g., as may be defined between a vector normal to the plane of input surface110aand a longitudinal axis120of stylus400, such as a zenith))); an azimuthal angle of stylus400relative to an axis of the input surface (e.g., an azimuthal angle122(Φ) (e.g., as may be defined between the polar angle118(θ) and a reference vector within the plane of input surface110a, such as an axis)); a vector or scalar representation of the angular position of stylus400relative to a plane of the input surface; three-dimensional coordinates (e.g., spherical, Cartesian, and so on) of one or more points along the length of stylus400relative to the input surface; and so on. In many embodiments, system1may be operative to monitor such variables over time to estimate rates of change therein as either scalar or vector quantities (e.g., velocity, acceleration, and so on). The operation of estimating or determining two-dimensional position coordinates of stylus400as a point (or area) within or parallel to a plane of the input surface, whether such operation is performed by electronic device100, performed by stylus400, and/or performed, at least in part, as a result of cooperation therebetween (or with one or more other electronic devices), is generally referred to herein as “locating” the stylus.

Electronic device100and/or stylus400can be configured to estimate and/or monitor the location of stylus400over time and compute differential or integral quantities such as, but not limited to, acceleration, velocity, total force applied, path length, and so on. For example, the operation of estimating the velocity and/or acceleration of stylus400relative to the input surface as stylus400is moved across that surface, whether such operation is performed by electronic device100, performed by stylus400, and/or performed, at least in part, as a result of cooperation therebetween (or with one or more other electronic devices), is generally referred to herein as estimating the “planar motion” of the stylus. The operation of estimating the angular velocity and/or acceleration of stylus400relative to a plane of the input surface as it is moved thereacross, whether performed by electronic device100, performed by stylus400, and/or performed, at least in part, as a result of cooperation therebetween (or with one or more other electronic devices), is generally referred to herein as estimating the “angular motion” of the stylus. Additionally or alternatively, electronic device100and/or stylus400can be configured to estimate the distance (e.g., Z-height) of a portion of stylus400(e.g., the tip of the stylus) from the input surface of device100, and such an estimated distance may be used to determine a “make or break” event between the stylus and device, such as for making a determination when a drawn graphical line should start or stop or a stylus lift off event should occur.

Electronic device100may be any portable, mobile, or hand-held electronic device configured to interact with stylus400for changing any suitable characteristic(s) of device100(e.g., any suitable graphical object input tool characteristics that may be utilized to render a graphical object) in response to manipulation of stylus400across an input surface of electronic device100. Alternatively, electronic device100may not be portable at all, but may instead be generally stationary. Electronic device100can include, but is not limited to, a media player, video player, still image player, game player, other media player, music recorder, movie or video camera or recorder, still camera, other media recorder, radio, medical equipment, domestic appliance, transportation vehicle instrument, musical instrument, calculator, cellular telephone, other wireless communication device, personal digital assistant, remote control, pager, computer (e.g., a desktop, laptop, tablet, server, etc.), merchant accessory (e.g., signature pad (e.g., as may be used in a check-out line of a merchant store during payment processing)), monitor, television, stereo equipment, set up box, set-top box, wearable device (e.g., watch, clothing, etc.), boom box, modem, router, printer, and combinations thereof. Electronic device100may include any suitable control circuitry or processor102, memory104, communications component106, power supply108, input component110, and output component112. Electronic device100may also include a bus114that may provide one or more wired or wireless communication links or paths for transferring data and/or power to, from, or between various other components of device100. Device100may also be provided with a housing101that may at least partially enclose one or more of the components of device100for protection from debris and other degrading forces external to device100. In some embodiments, one or more of the components may be provided within its own housing (e.g., input component110may be an independent keyboard or mouse within its own housing that may wirelessly or through a wire communicate with processor102, which may be provided within its own housing). In some embodiments, one or more components of electronic device100may be combined or omitted. Moreover, electronic device100may include other components not combined or included inFIG. 1. For example, device100may include any other suitable components or several instances of the components shown inFIG. 1. For the sake of simplicity, only one of each of the components is shown inFIG. 1.

Memory104may include one or more storage mediums, including for example, a hard-drive, flash memory, permanent memory such as read-only memory (“ROM”), semi-permanent memory such as random access memory (“RAM”), any other suitable type of storage component, or any combination thereof. Memory104may include cache memory, which may be one or more different types of memory used for temporarily storing data for electronic device applications. Memory104may store media data (e.g., music and image files), software (e.g., applications for implementing functions on device100(e.g., virtual drawing space applications, stylus detection applications, etc.)), firmware, preference information (e.g., media playback preferences), lifestyle information (e.g., food preferences), exercise information (e.g., information obtained by exercise monitoring equipment), transaction information (e.g., information such as credit card information), wireless connection information (e.g., information that may enable device100to establish a wireless connection), subscription information (e.g., information that keeps track of podcasts or television shows or other media a user subscribes to), contact information (e.g., telephone numbers and e-mail addresses), calendar information, any other suitable data, or any combination thereof.

Communications component106may be provided to allow device100to communicate with one or more other electronic devices or servers or subsystems (e.g., stylus400) using any suitable communications protocol(s). For example, communications component106may support Wi-Fi (e.g., an 802.11 protocol), Ethernet, Bluetooth™, near field communication (“NFC”), radio-frequency identification (“RIM”), high frequency systems (e.g., 900 MHz, 2.4 GHz, and 5.6 GHz communication systems), infrared, transmission control protocol/internet protocol (“TCP/IP”) (e.g., any of the protocols used in each of the TCP/IP layers), hypertext transfer protocol (“HTTP”), BitTorrent™, file transfer protocol (“FTP”), real-time transport protocol (“RTP”), real-time streaming protocol (“RTSP”), secure shell protocol (“SSH”), any other communications protocol, or any combination thereof. Communications component106may also include circuitry that can enable device100to be electrically coupled to another device or server or subsystem (e.g., stylus400or another user electronic device or server) and communicate with that other device, either wirelessly or via a wired connection.

Power supply108may provide power to one or more of the components of device100. In some embodiments, power supply108can be coupled to a power grid (e.g., when device100is not a portable device, such as a desktop computer). In some embodiments, power supply108can include one or more batteries for providing power (e.g., when device100is a portable device, such as a cellular telephone). As another example, power supply108can be configured to generate power from a natural source (e.g., solar power using solar cells).

One or more input components110may be provided to permit a user to interact or interface with device100and/or to sense certain information about the ambient environment. For example, input component110can take a variety of forms, including, but not limited to, a touch pad, trackpad, dial, click wheel, scroll wheel, touch screen, ultrasonic line sensor, ultrasonic imaging array, one or more buttons (e.g., a keyboard), mouse, joy stick, track ball, switch, photocell, force-sensing resistor (“FSR”), encoder (e.g., rotary encoder and/or shaft encoder that may convert an angular position or motion of a shaft or axle to an analog or digital code), microphone, camera, scanner (e.g., a barcode scanner or any other suitable scanner that may obtain product identifying information from a code, such as a linear barcode, a matrix barcode (e.g., a quick response (“QR”) code), or the like), proximity sensor (e.g., capacitive proximity sensor), biometric sensor (e.g., a fingerprint reader or other feature recognition sensor, which may operate in conjunction with a feature-processing application that may be accessible to electronic device100for authenticating or otherwise identifying or detecting a user), line-in connector for data and/or power, force sensor (e.g., any suitable capacitive sensors, pressure sensors, strain gauges, sensing plates (e.g., capacitive and/or strain sensing plates), etc.), temperature sensor (e.g., thermistor, thermocouple, thermometer, silicon bandgap temperature sensor, bimetal sensor, etc.) for detecting the temperature of a portion of electronic device100or an ambient environment thereof, a performance analyzer for detecting an application characteristic related to the current operation of one or more components of electronic device100(e.g., processor102), motion sensor (e.g., single axis or multi axis accelerometers, angular rate or inertial sensors (e.g., optical gyroscopes, vibrating gyroscopes, gas rate gyroscopes, or ring gyroscopes), linear velocity sensors, and/or the like), magnetometer (e.g., scalar or vector magnetometer), pressure sensor, light sensor (e.g., ambient light sensor (“ALS”), infrared (“IR”) sensor, etc.), thermal sensor, acoustic sensor, sonic or sonar sensor, radar sensor, image sensor, video sensor, global positioning system (“GPS”) detector, radio frequency (“RF”) detector, RF or acoustic Doppler detector, RF triangulation detector, electrical charge sensor, peripheral device detector, event counter, and any combinations thereof. Each input component110can be configured to provide one or more dedicated control functions for making selections or issuing commands associated with operating device100.

Electronic device100may also include one or more output components112that may present information (e.g., graphical, audible, and/or tactile information) to a user of device100. An output component of electronic device100may take various forms, including, but not limited to, audio speakers, headphones, data and/or power line-outs, visual displays (e.g., for transmitting data via visible light and/or via invisible light), antennas, infrared ports, flashes (e.g., light sources for providing artificial light for illuminating an environment of the device), tactile/haptic outputs (e.g., rumblers, vibrators, etc.), taptic components (e.g., components that are operative to provide tactile sensations in the form of vibrations), and any combinations thereof.

For example, electronic device100may include a display as output component112. Display112may include any suitable type of display or interface for presenting visual data to a user. In some embodiments, display112may include a display embedded in device100or coupled to device100(e.g., a removable display). Display112may include, for example, a liquid crystal display (“LCD”), a light emitting diode (“LED”) display, an organic light-emitting diode (“OLED”) display, a surface-conduction electron-emitter display (“SED”), a carbon nanotube display, a nanocrystal display, an organic electroluminescence display, electronic ink, or another type of display technology or combination of display technology types. Alternatively, display112can include a movable display or a projecting system for providing a display of content on a surface remote from electronic device100, such as, for example, a video projector, a head-up display, or a three-dimensional (e.g., holographic) display. As another example, display112may include a digital or mechanical viewfinder, such as a viewfinder of the type found in compact digital cameras, reflex cameras, or any other suitable still or video camera. In some embodiments, display112may include display driver circuitry, circuitry for driving display drivers, or both. Display112can be operative to display content (e.g., media playback information, application screens for applications implemented on electronic device100, information regarding ongoing communications operations, information regarding incoming communications requests, device operation screens, etc.) that may be under the direction of processor102. Display112can be associated with any suitable characteristic dimensions defining the size and shape of the display. For example, the display can be rectangular or have any other polygonal shape, or alternatively can be defined by a curved or other non-polygonal shape (e.g., a circular display). Display112can have one or more primary orientations for which an interface can be displayed, or can instead or in addition be operative to display an interface along any orientation selected by a user.

It should be noted that one or more input components110and one or more output components112may sometimes be referred to collectively herein as an input/output (“I/O”) component or I/O interface111(e.g., input component110and display112as I/O component or I/O interface111). For example, input component110and display112may sometimes be a single I/O component111, such as a touch screen, that may receive input information through a user's and/or stylus' touch of a display screen and that may also provide visual information to a user via that same display screen. Input component110of electronic device100may provide an input surface relative to which a system user may manipulate the orientation and position of stylus400to convey information to electronic device100. In many embodiments, such an input surface of input component110of electronic device100may be provided as a portion of a multi-touch display screen assembly (e.g., as a portion of I/O interface111with a display output component112). However, in other embodiments, such an input surface of input component110of electronic device100may be a non-display input surface, such as, but not limited to, a trackpad or drawing tablet, whether or not device100may also include a display output component. The input surface of input component110may be a foldable or flexible surface or display.

Processor102of device100may include any processing circuitry operative to control the operations and performance of one or more components of electronic device100. For example, processor102may be used to run one or more applications, such as an application103. Application103may include, but is not limited to, one or more operating system applications, firmware applications, virtual drawing space applications, stylus or other suitable accessory detection applications, media playback applications, media editing applications, pass applications, calendar applications, state determination applications (e.g., device state determination applications, stylus state determination applications, accessory state determination applications, etc.), biometric feature-processing applications, compass applications, health applications, thermometer applications, weather applications, thermal management applications, force sensing applications, device diagnostic applications, video game applications, or any other suitable applications. For example, processor102may load application103as a user interface program or any other suitable program to determine how instructions or data received via an input component110(e.g., due to interaction with a tip of stylus400) and/or any other component of device100(e.g., stylus data from stylus400via communications component106, etc.) may manipulate the one or more ways in which information may be stored on device100(e.g., in memory104) and/or provided to a user via an output component112and/or to a remote subsystem (e.g., to stylus400and/or to any other electronic device or server via communications component106). Application103may be accessed by processor102from any suitable source, such as from memory104(e.g., via bus114) or from another device or server (e.g., from stylus400via communications component106, and/or from any other suitable remote source via communications component106). Electronic device100(e.g., processor102, memory104, or any other components available to device100) may be configured to process graphical data at various resolutions, frequencies, intensities, and various other characteristics as may be appropriate for the capabilities and resources of device100. Processor102may include a single processor or multiple processors. For example, processor102may include at least one “general purpose” microprocessor, a combination of general and special purpose microprocessors, instruction set processors, graphics processors, video processors, and/or related chips sets, and/or special purpose microprocessors. Processor102also may include on board memory for caching purposes. Processor102may be implemented as any electronic device capable of processing, receiving, or transmitting data or instructions. For example, process102can be a microprocessor, a central processing unit, an application-specific integrated circuit, a field-programmable gate array, a digital signal processor, an analog circuit, a digital circuit, or combination of such devices. Processor102may be a single-thread or multi-thread processor. Processor102may be a single-core or multi-core processor. Accordingly, as described herein, the term “processor” may refer to a hardware-implemented data processing device or circuit physically structured to execute specific transformations of data including data operations represented as code and/or instructions included in a program that can be stored within and accessed from a memory. The term is meant to encompass a single processor or processing unit, multiple processors, multiple processing units, analog or digital circuits, or other suitably configured computing element or combination of elements.

Stylus400may be any suitable accessory, digital input tool, marking tool, smart pen, smart brush, wand, chisel, user-manipulated electronic input device, hand-held input device, and/or the like that may be configured to interact with (e.g., provide input to) electronic device100. Stylus400may include any suitable control circuitry or processor402, which may be similar to any suitable processor102of device100, application403, which may be similar to any suitable application103of device100, memory404, which may be similar to any suitable memory104of device100, communications component406, which may be similar to any suitable communications component106of device100, power supply408, which may be similar to any suitable power supply108of device100, input component410, which may be similar to any suitable input component110of device100, output component412, which may be similar to any suitable output component112of device100, I/O interface411, which may be similar to any suitable I/O interface111of device100, bus414, which may be similar to any suitable bus114of device100, and/or housing401, which may be similar to any suitable housing101of device100. In some embodiments, one or more components of stylus400may be combined or omitted. Moreover, stylus400may include other components not combined or included inFIG. 1. For example, stylus400may include any other suitable components or several instances of the components shown inFIG. 1or only some but not all of the components shown inFIG. 1. For the sake of simplicity, only one of each of the components is shown inFIG. 1.

Moreover, as shown, system1may include one or more additional styli, such as one or more of styli400a,400b, and400c, and/or one or more other types of accessory, such as accessory400d, each of which may include any suitable components, such as a processor, application, memory, communications component, power supply, input component, output component, I/O interface, bus, housing, and/or the like, and may be similar to stylus400. While each stylus of system1may be operative to be used with respect to an input surface of device100(e.g., one at a time (e.g., by a user)), each stylus of system1may differ from one another with respect to one or more physical characteristics (e.g., color, weight, size, shape, material, circuitry, etc.) and/or with respect to one or more device input tool characteristics (e.g., graphical object input tool characteristics) associated with the stylus as may be determined by device100for defining any suitable device characteristic(s) (e.g., rendered characteristic(s) (e.g., color, thickness, shape, intensity, and/or the like) of a graphical object rendered by device100) in response to manipulation of the stylus with respect to an input surface of device100.

Generally and broadly,FIGS. 1A-1Dreference user input system1including electronic device100and stylus400. A user U manipulates the orientation and position of stylus400relative to input surface input component110a(e.g., a particular input component110) of electronic device100in order to convey information to electronic device100. User input system1may be configured to perform or coordinate multiple operations such as, but not limited to, locating stylus400, estimating the angular position of stylus400, estimating the magnitude of force by stylus400to input surface110a, determining a variable setting of a variable input component410of stylus400, determining a variable setting of an application103running on electronic device100(e.g., a virtual drawing space application), and/or a combination thereof. User input system1can perform these and other operations at the same time or at different times. In one non-limiting example, the operation of determining the location of stylus400can be performed simultaneously with the operation of determining the angular position of stylus400, while the operation of estimating the magnitude of force by stylus400to input surface110amay be performed only periodically and/or based on whether electronic device100is configured to accept force input from stylus400given a particular operational mode of electronic device100(or of stylus400) at a particular time.

FIG. 1Adepicts user U gripping a barrel or handle or body portion417of stylus400extending between a front tip portion415of stylus400and a rear tip portion419of stylus400. User U may slide a tip portion, such as tip portion415, of stylus400across input surface110aof electronic device100to interact with a user interface presented or rendered on display output component112aof electronic device100, which may be positioned below at least a portion of input surface110aor integrated with at least a portion of input surface110ato provide I/O interface111aof device100. Although, in other embodiments, it is to be understood that device100may not include a display output component or may not include a display output component co-located with input surface110a. Input surface110amay be a foldable or flexible surface or display. As shown inFIGS. 1A-1D, device100may be presented as a tablet computing device as an example only, while many other electronic devices (with or without displays positioned below a stylus input surface) are envisioned. For example, the electronic device of user input system1can be implemented as a peripheral input device, a trackpad, a drawing tablet, and the like.

Stylus400may take various forms to facilitate use and manipulation by user U. In the illustrated example ofFIGS. 1A-1D, stylus400may have a general form of a writing instrument, such as a pen or a pencil with a cylindrical body417with two ends, such as a first end terminated at front portion415and a second end terminated at rear portion419. Either one or both of portions415and419can be removable, affixed to body417, or an integral part of body417. User U may slide front portion415of stylus400across input surface110ato convey information to electronic device100. Electronic device100can interpret the user's manipulation of stylus400in any implementation-specific and suitable manner.

Body417of stylus400can be formed from any number of suitable materials, such as from plastics, metals, ceramics, laminates, glass, sapphire, wood, leather, synthetic materials, dielectric material, or any other material or combination of materials. Body417can form an outer surface (or partial outer surface) and protective case for one or more internal components of stylus400(e.g., as a portion of housing401). Body417can be formed of one or more components operably connected together, such as a front piece and a back piece or a top clamshell and a bottom clamshell. Alternatively, body417can be formed of a single piece (e.g., uniform body or unibody). In some embodiments, body417may be configured, partially or entirely, as an optical signal diffuser to diffuse an infrared signal or another optical signal such as the light emitted from a multi-color light-emitting diode. In other cases, body417may be configured, entirely or partially, as an antenna window, allowing for wireless communications and/or electric fields to pass therethrough. Body417can be formed from a material doped with an agent configured to provide body417with a selected color, hardness, elasticity, stiffness, reflectivity, refractive pattern, texture, and so on. In other examples, the doping agent can confer other properties to body417including, but not necessarily limited to, electrical conductivity and/or insulating properties, magnetic and/or diamagnetic properties, chemical resistance and/or reactivity properties, infrared and/or ultraviolet light absorption and/or reflectivity properties, visible light absorption and/or reflectivity properties, antimicrobial and/or antiviral properties, oleophobic and/or hydrophobic properties, thermal absorption properties, pest repellant properties, colorfast and/or anti-fade properties, antistatic properties, liquid exposure reactivity properties, and so on.

Body417can exhibit a constant or a variable diameter cross-section. As illustrated, for example, the cylindrical cross-section view of body417may maintain a substantially constant diameter from tip portion415to rear portion419. In other embodiments, body417can include a variable cross-section (e.g., a “profile” of body417can change across the length of body417). In one example, the diameter of body417may be smaller near tip portion415than at rear portion419. In some examples, the diameter of body417may bulge outward in the middle of body417between portions415and419. In some cases, the profile of body417can follow a mathematical function such as a bump function, a Gaussian function, or a step function. Body417may include one or more grip features (not shown) such as embossments or impressions, closely-spaced channels, protrusions, projections, and/or the like. In some cases, a grip feature can be formed from a different material than body417(e.g., grip feature(s) may be formed from a polymer material exhibiting high friction).

Although illustrated as a cylinder, body417need not take a cylindrical shape in all embodiments. Accordingly, as used herein, the term “diameter” may refer to the linear distance that can connect two points of a two-dimensional shape, whether the shape is circular or otherwise. For example, stylus400can include a body417with an n-sided polygonal cross-section (e.g., a vesica piscis cross-section, a triangular cross-section, a square cross-section, a pentagonal cross-section, and so on) that either varies in diameter or is constant in diameter. In some examples, a cross-section of body417may be axially symmetric, although this is not required, as certain styluses in accordance with embodiments described herein may include body417with a cross-section that is reflectionally symmetric along one axis while being reflectionally asymmetric along another. In still further examples, body417can be formed into an ergonomic shape, including grooves, indents, and/or protrusions configured to enhance the comfort of user U. In some cases, body417may include a tapered section that decreases in diameter, linearly or non-linearly, toward tip portion415. The diameter of body417at the interface of body417and tip portion415may be substantially similar to the diameter of tip portion415at that location. In this manner, the external surfaces of portions415and417may form a substantially continuous external surface of housing401of stylus400. Additionally or alternatively, the diameter of body417at the interface of body417and rear portion419may be substantially similar to the diameter of rear portion419at that location. In this manner, the external surfaces of portions417and419may form a substantially continuous external surface of housing401of stylus400.

One or more of portions415-419of stylus400can define one or more apertures416in which one or more input components410and/or one or more output components412of stylus400, such as a button, a dial, a slide, a force pad, a touch pad, audio component, haptic component, and the like, may at least partially reside. The apertures (and, correspondingly, the input/output components associated therewith) can be defined at a lower end of body417nearby tip portion415, such that the input/output components may be conveniently located near where user U may rest the user's forefinger when grasping stylus400. As one example, an aperture416may expose at least a portion of a simple mechanical switch or button input component410that may be manipulated by user U for adjusting a variable setting of stylus400(e.g., stylus400may be configured to operate in a first mode when such an input component is manipulated in a first manner and in a second mode when such an input component is manipulated in a second manner (e.g., to select different patterns of stylus400bdescribed herein)).

Rear portion419of stylus400, or more generally, a “cap” of stylus400, may be configured to provide a cosmetic end to body417. In some cases, rear portion419may be formed integrally with body417. In some cases, rear portion419may be formed similarly to front portion415for providing another tip feature for interacting with an input surface of device100(e.g., stylus400may be flipped over by user U to drag portion419across input surface input component110aof electronic device100rather than to drag portion415across input surface input component110aof electronic device100, which may enable different user-selectable interactions with device100). Any portion or the entirety of rear portion419may expose or provide at least a portion of a simple mechanical switch or button or any other suitable input component410that may be manipulated by user U for adjusting a variable setting of stylus400(e.g., stylus400may be configured to operate in a first mode when such an input component is manipulated in a first manner and in a second mode when such an input component is manipulated in a second manner (e.g., to select different patterns of stylus400bdescribed herein)).

Tip portion415of stylus400, or more generally the “tip,” may be configured to contact or nearly contact input surface110aof device100in order to facilitate interaction between user U and device100. Tip415may taper to a point, similar to a pen, so that user U may control stylus400with precision in a familiar form factor. In some examples, tip415may be blunt or rounded, as opposed to pointed, or may take the form of a rotatable or fixed ball. Tip415may be formed from a softer material than input surface110a. For example, tip415can be formed from a silicone, a rubber, a fluoro-elastomer, a plastic, a nylon, conductive or dielectric foam, a brass or metal ball with a polymer coating or dielectric coating (e.g., a thin coating with a high dielectric constant) or any other suitable coating, or any other suitable material or combination of materials. In this manner, drawing of tip415across input surface110amay not cause damage to input surface110aor layers applied to input surface110a, such as, but not limited to, anti-reflective coatings, oleophobic coatings, hydrophobic coatings, cosmetic coatings, ink layers, and the like. Tip415can be configured to be removably attached to body417, such as via threadings/screws, detents and/or recesses, interference-fit or snap-fit, and/or magnetic attraction, and/or the like.

Electronic device100may locate and/or estimate the angular position of stylus400substantially in real time. Device100can perform these operations with and/or without communications from stylus400. As shown inFIGS. 1A-1D, device100may be depicted as a tablet computing device, although this form-factor is not required of all embodiments (as noted above). For example, device100can be any suitable device, such as a desktop computer, laptop computer, cellular phone, an industrial or commercial computing terminal, a medical device, a peripheral or integrated input device, a hand-held or battery powered portable electronic device, a navigation device, a wearable device, and so on. Display output component112amay be positioned below input surface110aor may be integrated with input surface110a.

The communication interfaces, whether between electronic device100and stylus400or between device100and another device or server, or otherwise, can be implemented as capacitive coupling interfaces (e.g., via I/O interfaces111and411(e.g., as capacitive coupling interface data51(e.g., signal(s) received by or adjusted by or made available by one of the interfaces to the other interface))), inductive interfaces, resonant interfaces, optical interfaces, acoustic interfaces, magnetic interfaces, wireless interfaces, Bluetooth interfaces (e.g., via communication components106and406(e.g., as wired/wireless communication interface data56)), universal serial bus interfaces, Wi-Fi interfaces, TCP/IP interfaces, network communications interfaces, or any other suitable communication interfaces. In some embodiments, stylus400may not be configured to communicate with device100via any communication component interfaces (e.g., stylus400may not be provided with any communications component (e.g., no communications component406) but may still communicate with device100using any suitable I/O interface411(e.g., via I/O interfaces111and411(e.g., as capacitive coupling interface data51)))). Electronic device100may provide information related to externally connected or communicating devices and/or software executing on such devices, messages, video, operating commands, and so forth (and may receive any of the foregoing from an external device), in addition to communications. Input surface110amay cooperate with housing101of device100to form an external surface thereof. In some cases, a front surface of input surface110acan be flush with an external surface of housing101, although this is not required of all embodiments. In some examples, input surface110amay stand proud of at least a portion of housing101. Input surface110amay be formed from glass or another suitable material, such as plastic, sapphire, metal, ceramic, ion-implanted glass, and so on. In some cases, input surface110amay be a solid material, whereas in other cases, input surface110amay be formed by laminating or adhering several materials together. Display component112amay be positioned below, or integrated with, input surface110a, where device100may utilize display112ato render images to convey information to the user. Display112acan be configured to show text, colors, line drawings, photographs, animations, video, and the like. Input surface110aand/or display112amay provide a foldable or flexible surface or display.

Device100can also include a sensor layer input component110bpositioned below, or integrated with, input surface110aand/or display112a, where device100may utilize the sensor layer to, among other purposes, detect the presence and/or location of stylus400on input surface110a. In other examples, device100may utilize sensor layer110bto detect the presence of another object on input surface110a, such as a finger of the user. In still further examples, device100may utilize sensor layer110bto detect the force with which an object, such as stylus400, presses on input surface110a. Such a sensor layer110b(e.g., of input surface input component110a) can be optically transparent or opaque. If sensor layer110bof a particular embodiment is disposed within display112a, sensor layer110bmay be optically transparent so as to not impact the clarity of the display. In another example, sensor layer110bmay be disposed around the perimeter of the display, positioned below a bezel surrounding the display, and/or the like. In this embodiment, sensor layer110bneed not be optically transparent. Input surface110aand/or sensor layer110bmay provide at least a portion of a foldable or flexible surface or display. Sensor layer110bmay be a metallic grid that may be positioned between and not blocking one or more light-emissive elements of I/O interface111a(e.g., for providing on-cell or in-cell electrodes). Additionally or alternatively, electrodes of sensor layer110bcould be shared with display electronics of I/O interface Ilia (e.g., for providing in-cell electrodes).

Next, reference is made to the operation of locating stylus400on input surface110aof device100using sensor layer110bof device100. Device100can locate an interface portion, such as tip415, of stylus400, and estimate the Cartesian coordinates thereof, in a number of suitable ways. In typical embodiments, stylus400is located as a result of cooperation between stylus400and device100. Generally and broadly, stylus400may be operative to generate and/or adjust (e.g., using any suitable I/O interface or I/O component or I/O circuitry411) an electric field (e.g., an electric field having a small effective diameter along input surface110a, or an electric field where potential lines may be nearly spheres but where the electric field lines may be strongly curved but not circular). This “stylus electric field” (e.g., as adjusted and/or generated (e.g., caused) by stylus400) may be provided by a stylus interface portion (e.g., tip415) and may intersect input surface110awhen the stylus interface portion of stylus400is placed on or near surface110a. Device100may detect the stylus electric field and estimate the location of stylus400(e.g., of the stylus interface portion (e.g., tip415) based on the location (and/or area) at which the stylus electric field is detected). Sensor layer110bmay be configured to detect stylus electric fields caused by stylus400, where layer110bmay include a number of capacitance sensing nodes that can be located on or between any suitable layer on or within display112aand/or on or within input surface110a. The capacitive sensing nodes may be formed, at least in part, from an optically transparent conductor, such as, but not limited to, metal oxides such as indium-tin oxide and antimony-tin oxide, nanowire patterns formed from silver nanowire, carbon nanotubes, platinum nanowire, gold nanowire, and so on, thin deposits of metal, and the like. The capacitive sensing nodes may be configured to operate in any suitable capacitance mode or projected capacitance touch (“PCT”) mode, such as a self-capacitance mode, a mutual capacitance mode, or any other suitable capacitance mode or combination thereof, thereby capacitively coupling to stylus400and detecting signals and fields caused by stylus400.

Stylus400may cause a substantially-spherical or hemispherical or any other suitably shaped stylus electric field to be provided thereby (e.g., from tip415by I/O circuitry411). This stylus field may affect the capacitance (e.g., mutual capacitance or self-capacitance) of each capacitive sensing node nearby the stylus interface portion. Device100may locate stylus400on input surface110aby monitoring each capacitive sensing node or an appropriate set of capacitive sensing nodes for these capacitive changes and estimating the location at which such changes (if any) have occurred. As used herein, the term “tip signal” may generally refer to an electrical signal provided by or received by stylus400at the stylus interface portion (e.g., tip415). As used herein, the term “tip field” may generally refer to the stylus electric field provided by the stylus interface portion (e.g., tip415) in response to the tip signal. The tip field may take any suitable shape, but in many embodiments, the tip field takes a substantially spherical (or hemispherical) shape and may be modeled as a point source monopole electric field. The area of input surface110a(or a plane parallel to input surface110a) intersected by the tip field may be generally referred to herein as the “tip field intersection area,” which may be any suitable shape, such as substantially circular. A perimeter of the tip field intersection area may be defined as the boundary after which the power density (e.g., magnitude) of the tip field received by electronic device100may be below a selected threshold. In one example, the circumference of the tip field intersection area may be defined at the half-power point of the tip field. In other words, in this example, the tip field intersection area may be defined as a portion of input surface110aintersected by the tip field with a magnitude at least greater than half of the power at which that field was provided. A charge footprint (e.g., charge profile) may be counted out as far as it is above a noise floor.

The tip signal can have at least one alternating current component that, via capacitive coupling or another suitable sensing technique, may be received (e.g., as the tip field) by the sensor layer of the electronic device. Many embodiments are described herein with reference to a sensor layer110bof electronic device100that may be configured to detect the tip signal by monitoring mutual capacitance. However, it may be appreciated that electronic device100can be appropriately configured in any implementation-specific manner to detect the tip field. For example, electronic devices can include a sensor layer configured to monitor for changes in the self-capacitance of one or more capacitive sensor nodes. In other examples, an electronic device can be configured to operate in both a self-capacitance mode and a mutual capacitance mode. In other embodiments, other sensing techniques can be used to determine the location and relative position of the tip field. As noted above, sensor layer110bcan also be used to detect one or more fingers of user U while simultaneously detecting the tip field. In these cases, electronic device100can accept both touch input and stylus input.

In many cases, processor102of device100may be configured to detect the tip signal received through sensor layer110bfrom stylus400via capacitive coupling. Processor102may be configured to demodulate, decode, or otherwise filter one or more raw signals received from sensor layer110band/or from any other sensor/input component in order to obtain the tip signal, and/or data that may be modulated therewith and/or any other suitable data. The operation of obtaining the tip signal, as performed by processor102(or another component communicably coupled to sensor layer110b), can be accomplished in a number of implementation-specific ways, suitable for any number of embodiments.

Processor102may perform (or assist with the performance op the operation of locating stylus400on input surface110aemploying any suitable techniques once the tip signal is obtained, and the tip field intersection area is determined. Processor102can further use such information for further processing and interpretation once the location of stylus400is estimated.

In many embodiments, processor102may be configured to obtain estimations of the location of stylus400within certain statistical bounds (e.g., within an error of 100 micrometers, within 50 micrometers, within 10 micrometers, or any other suitable bounds). One may appreciate that the accuracy and/or precision of the operation of locating stylus400by device100may differ from embodiment to embodiment. In some cases, the accuracy and/or precision of the operation(s) may be substantially fixed, whereas in other cases, the accuracy and/or precision of the operation(s) may be variable depending upon, among other variables, a user setting, a user preference, a speed of the stylus, an acceleration of the stylus, a setting of a program103operating on electronic device100, a setting of electronic device100, an operational mode of electronic device100, a power state of device100, a power state of stylus400, an identification of a setting or characteristic of stylus400, and so on.

The tip signal can include certain information and/or data that may be configured to identify stylus400to electronic device100. Such information may generally be referred to herein as “stylus identity” information (e.g., information indicative of a particular stylus tip of stylus400awith a particular harmonic and/or phase as described herein). This information and/or data may be received by sensor layer110band interpreted, decoded, and/or demodulated by processor100of device100. Processor102may utilize stylus identity information (or an absence thereof) in any suitable manner including, but not limited to, accepting or rejecting input from a particular stylus, accepting input from multiple styli and/or from a single stylus, permitting or denying access to a particular functionality of the electronic device, applying a particular stylus profile, restoring one or more settings of the electronic device, notifying a third party that the stylus is in use, applying a setting to the electronic device, applying a setting to a program operating on the electronic device (e.g., which may include updating a user interface on display112aor otherwise of device100), changing a line thickness, color, pattern, erasure, and so on of a graphical object to be rendered by a graphics program of the electronic device, changing a setting of a video game operating on the electronic device, and so on. Processor102may be operative to receive stylus identity information for stylus400. Additionally or alternatively, processor102may be operative to receive stylus identity information from each one of two different styluses that may be interacting with device100. For example, processor102may be operative to determine that a first detected stylus is positioned 3 centimeters away from a second detected stylus, which may be communicated via display112ato the user(s) in any suitable manner Additionally or alternatively, any suitable data communicated from stylus400may be operative to include certain information and/or data that may serve to identify a particular setting or preference of the user or of the stylus (e.g., a current setting of a variable input component or other suitable reconfigurable characteristic of the stylus (e.g., data indicative of a particular property of an input component410of stylus400)), where such information may generally be referred to herein as “stylus setting” information (e.g., information indicative of a particular pattern of stylus400bas described herein). Processor102may be operative to use stylus setting information (or an absence thereof) in any suitable manner including, but not limited to, applying a setting to the electronic device, applying a setting to a program operating on the electronic device (e.g., which may include updating a user interface on display112aor otherwise of device100), changing a line thickness, color, pattern, erasure, and so on of a graphical object to be rendered by a graphics program of the electronic device, changing a setting of a video game operating on the electronic device, and so on.

A stylus of system1may not be provided with any power supply (e.g., no battery or any other suitable power supply like power supply400), such that the stylus may not be operative to generate any stylus electric field independently (e.g., without being stimulated by an external stimulus). Instead, a stylus may be provided with limited stylus I/O circuitry that may be operative to be stimulated by an external stimulus, such as a device stimulus that may be generated by device I/O circuitry of device I/O interface111aof electronic device100and that may be operative to stimulate the stylus I/O circuitry when located proximate to device I/O interface111aand/or by user U when holding stylus400, whereby that stimulation of the stylus I/O circuitry may be operative to enable the stylus I/O circuitry to provide any suitable stylus electric field that may then be detected by device100for estimating the location of the stylus. Not only may such stylus I/O circuitry be configured to require no internal power supply for providing a unique stylus electric field, but also such stylus I/O circuitry, when stimulated, may be configured to provide a stylus electric field that may be distinguishable by device100from an electric field that may be provided by a user's direct contact with device I/O interface111a.

For example,FIGS. 2-2Gillustrate stylus400a, alone and/or in combination with device100of system1, that may include stylus I/O circuitry411a, where stylus I/O circuitry411amay be operative to be stimulated only by external stimulus, such as a device stimulus that may be generated by device I/O circuitry of device I/O interface111aof electronic device100and/or by user U when holding stylus400a, whereby that stimulation of stylus I/O circuitry411amay be operative to enable stylus I/O circuitry411ato provide any suitable stylus electric field that may then be detected by device100for estimating the location of stylus400. As shown byFIGS. 2 and 2C, for example, stylus400amay include a barrel or handle or body portion417aextending between a front tip portion415aand a rear tip portion419a, where body portion417amay be configured to be held by user U as the user may slide a tip portion of stylus400across input surface110aof device I/O interface111aof device100.

Stylus I/O circuitry411amay include body stylus circuitry427athat may be electrically coupled to front tip stylus circuitry426aand/or to rear tip stylus circuitry436a. Body stylus circuitry427amay be any suitable circuitry that may be operative to be electrically coupled (e.g., capacitively coupled) to user U when user U is holding stylus400aabout at least a portion of body portion417a. As shown inFIGS. 2 and 2C, for example, body stylus circuitry427amay be at least one conductive wire extending along at least a portion of a length of body portion417aof stylus400a, which may be insulated by any suitable insulation428a. Alternatively, body stylus circuitry427amay be provided by a conductive (e.g., copper) tape along a portion of body417a, where such tape may be positioned under any suitable insulation, such as a finger pad of any suitable material. Any suitable housing401amay be provided to protect body stylus circuitry427a, such as a plastic housing. In some embodiments, such a housing may be operative to provide insulation428a. Additionally or alternatively, at least a portion of body stylus circuitry427amay be at least partially exposed via housing401aand/or insulation428afor enabling direct contact by user U. When user U is holding stylus400aabout and/or along a portion of body417a, a capacitance or user-handle capacitor UHC may be inherently formed (e.g., as shown inFIGS. 2B, 2E, and 2G). The capacitance of user-handle capacitor UHC may be relatively large compared to a panel to tip capacitance (e.g., electric field response capacitances SDC between front tip interface component421aand each one of array trace row111arand array trace column111acof one or more nodes111anproximate front tip interface component421a), but not so large that electrostatic discharges would be likely to damage the device. For example, the capacitance of user-handle capacitor UHC may be any suitable capacitance, such as a capacitance in the range of 1.0 picofarad to 10.0 picofarads, as a panel to tip capacitance may be in the range of 50.0 femtofarads to 200.0 femtofarads. The capacitance of user-handle capacitor UHC may be able to stand off the voltage of typical electrostatic discharge impulses (e.g., 10 kilovolts or so).

Stylus I/O circuitry411amay include a front tip interface component421athat may provide at least a portion of front tip portion415a. Front tip interface component421amay be the portion of stylus400aconfigured to directly interface with device I/O interface111a. For example, front tip interface component421amay be formed from any suitable material, including, but not limited to, silicone, rubber, fluoro-elastomer, plastic, nylon, conductive or dielectric foam, metal (e.g., brass (e.g., a brass ball with a dielectric or polymer coating (e.g., a thin coating with a high dielectric constant))), or any other suitable material or combination of materials. In this manner, drawing of front tip interface component421aacross input surface110amay not cause damage to input surface110aor layers applied to input surface110a, such as, but not limited to, anti-reflective coatings, oleophobic coatings, hydrophobic coatings, cosmetic coatings, ink layers, and the like. Front tip interface component421acan be configured to be removably attached to body417a, such as via threadings/screws, detents and/or recesses, interference-fit or snap-fit, and/or magnetic attraction, and/or the like. Transit of any stylus electric field may be provided from front tip interface component421aand not from other portions of stylus I/O circuitry411a. Front tip interface component421amay be any suitable shape, such as a sphere or hemisphere, of any suitable size. For example, in some particular embodiments, front tip interface component421amay be provided as a ball (e.g., a solder ball and/or brass ball) of any suitable diameter, such as 2 millimeters or 3.6 millimeters in diameter, or in the range of 1.7 millimeters to 2.3 millimeters, or in the range of 3.3 millimeters to 3.9 millimeters, or, as one example, a brass or metal ball with a diameter of 3.6 millimeters and with a coating thereabout of about 0.2 millimeters thickness. Front tip interface component421amay be a metal or brass ball with a coating or a conductive polymer ball shape, with a total diameter of about 3.4 millimeters or 3.0 millimeters or 2.4 millimeters or 2.0 millimeters. Front tip interface component421amay be configured to provide the same footprint area (e.g., tip field intersection area (e.g., of charge)) on input surface110ano matter (e.g., substantially no matter) the angle of axis120with respect to a plane of input surface110a. The size of front tip interface component421amay be made as small as possible to enable precise localization of front tip portion415awith respect to device I/O interface111a.

Front tip stylus circuitry426amay be positioned between and electrically coupled to each one of front tip interface component421aand a portion (e.g., a front end) of body stylus circuitry427a. Front tip stylus circuitry426amay be configured as any suitable circuitry that may be operative to provide a non-linear load between body stylus circuitry427aand front tip interface component421awhen user U is holding body417aof stylus400asuch that front tip interface component421aof stylus400amay be stimulated by a device stimulus that may be generated by device I/O circuitry of device I/O interface111aof electronic device100. For example, front tip stylus circuitry426amay include any suitable non-linear electrical circuitry423athat may be electrically coupled (e.g., in series) between front tip interface component421aand body stylus circuitry427a. Non-linear electrical circuitry423amay include any suitable number of any suitable type(s) of non-linear electrical elements, such as at least one diode422a. Diode422amay be any suitable type of diode, such as a Schottky diode, a transistor in diode configuration (e.g., a diode connected transistor), and/or the like. In some embodiments, non-linear electrical circuitry423amay include any suitable number (e.g., two or three or four or more) of diodes422athat may be coupled together in series (e.g., a cathode of one diode may be coupled to an anode of a next diode and/or the like) or in parallel. Alternatively, as shown, only a single diode422amay be provided by non-linear electrical circuitry423a, where an anode A of diode422amay be electrically coupled to body stylus circuitry427aand where a cathode C of diode422amay be electrically coupled to front tip interface component421a.

Device I/O circuitry of I/O interface111amay be configured in any suitable manner to provide a device stimulus for stimulating front tip interface component421aof stylus400awhen front tip interface component421aof stylus400is positioned on or close to input surface input component110aof I/O interface111aas user U may drag front tip interface component421aacross input surface input component110a. For example, sensor layer110bof the device I/O circuitry of I/O interface111amay be configured to monitor changes in mutual capacitance that may be caused by a stylus electric field provided by stylus400aat one or more capacitive sensing nodes of sensor layer110b. As shown inFIGS. 2A, 2B, 2D, and2E, for example, sensor layer110bmay be configured to provide an array of mutual capacitive sensors or sensing nodes that may be operative to enable mutual capacitance PCT sensing techniques. Sensor layer110bmay provide an array or grid of any suitable number of array trace columns111acand any suitable number of array trace rows111ar, any two of which may intersect to provide a sensing node Wan. A capacitance or mutual node capacitor MNC may be inherently formed at each sensing node111an(e.g., as shown inFIGS. 2A, 2B, 2D, and 2E). When any suitable electrical signal (e.g., transmit signal) TS may be provided along one, some, or each of array trace columns111acby any suitable transmitter circuitry T (e.g., a high frequency driven amplifier and/or a voltage source V controlled by a waveform w (e.g., a sinusoid or trapezoid shaped waveform) of any suitable magnitude (e.g., 6.5 volts amplitude (e.g., peak to peak)) and/or of any suitable frequency (e.g., 150 kHz or 70 kHz or 40 kHz or the like), or any other suitable configuration), any suitable electrical signal (e.g., receive signal) RS may be detected by any suitable receiver circuitry R that may be provided along each one of array trace rows111ar. While signal TS (e.g., a voltage) is applied to an array trace column111ac, bringing a finger or conductive stylus close to the surface of sensor layer110bmay change the local electrostatic field (e.g., in response to signal TS and/or capacitance MNC stimulating front tip interface component421aof stylus400a), which in turn may reduce the mutual capacitance. The capacitance change at every individual point on the array grid can be measured to determine the touch location accurately by measuring and analyzing the signal in the other axis, such as signal RS along each array trace row111ar. Mutual capacitance may allow multi-touch operation where multiple fingers, palms, or styli can be accurately tracked at the same time. For example, as shown inFIGS. 2A and 2B, capacitance MNC and/or signal TS at one or more nodes111anmay be received by front tip interface component421aand may stimulate front tip stylus circuitry426a, which, in turn, may be operative to provide a non-linear load between body stylus circuitry427aand front tip interface component421afor generating a stylus electric field response for changing the electric field local to one or more nodes111an. For example, the reaction of the stimulus and the non-linear load may create harmonics, which may then be received by one or more nodes, such as by node111anofFIGS. 2A and 2Band/or by an associated array trace row111arand/or by an associated array trace column111ac, for example, via electric field response capacitances SDC between front tip interface component421aand each one of array trace row111arand array trace column111acof one or more nodes Wan proximate front tip interface component421a. Such harmonics may then be detected as signal RS along an array trace row111arof one or more nodes Wan on the array grid and then such signals may be analyzed (e.g., using any suitable algorithms or detection applications103of device100(e.g., at processor102or any suitable circuitry (e.g., of I/O interface111a))) to determine the touch location of front tip interface component421aof stylus400aalong input surface input component110aof I/O interface111a. Therefore, signal TS may be adjusted by the non-linearity of front tip stylus circuitry426aat or near a node111anand that adjustment (e.g., as harmonics) may be detected as signal RS by that node111an.

When a frequency may be transmitted through a trace of the mutual capacitance sensor array, such as by signal TS along one or more array trace columns111ac, the signal may drive a current back and forth through non-linear electrical circuitry423aof front tip stylus circuitry426a(e.g., through one or more non-linear electrical elements, such as through at least one diode422a) when user U holding body417aof stylus400apositions front tip interface component421aof stylus400aproximate at least one of the array trace columns. Such driving of current back and forth through non-linear electrical circuitry423amay enable front tip interface component421ato see a modulated version of signal TS rather than a pure version of signal TS because front tip stylus circuitry426amay be loaded by a non-linear bias, such that current may pass through front tip stylus circuitry426amore easily in one direction but may be clipped in the other direction for providing a harmonic. For example, when front tip stylus circuitry426aincludes a single diode422a, a second harmonic of signal TS may be provided by front tip interface component421a. Therefore, when such a stylus400amay be known to be available to a user of device100, device100may be configured (e.g., via any suitable application and/or algorithm(s) or control circuitry for handling I/O interface111a) to look for a second harmonic of signal TS along one or some or each array trace row111ar(e.g., by signal RS) for determining the location of stylus400a, where the amount of second harmonic that may be detected for each row or node111anmay depend on how close that row or node may be to front tip interface component421aof stylus400a. Such a second harmonic may be generated by the rectification by the diode of the transmit voltage signal TS, capacitively divided down. A divider (e.g., capacitor divider) may be provided by system1, as may be made up of a capacitance of front tip interface component421aof stylus400ato the transmit plane of sensor layer110bor otherwise of I/O interface111aversus the impedance of front tip stylus circuitry426a(e.g., of diode422a), which may include its junction capacitance. Front tip interface component421amay be configured to have adequate effective capacitance for passive location using projective capacitance, such as, for example, an effective capacitance of 200 femtofarads or any other suitable magnitude.

Once a charge on a transmit plane of I/O interface111a(e.g., signal TS) may be seen to be modulated at a harmonic (e.g., a second harmonic (e.g., by I/O interface circuitry411aof stylus400a)), I/O interface111amay be configured to act as a transmitter of that harmonic. Such a harmonic of a transmit signal TS, as may be effected by non-linearity of front tip stylus circuitry426a, may be unique compared to any adjustment or effect that may be caused by a direct touch or near touch by user U (e.g., by a finger of user U) at I/O interface111a, such that device100may be configured to distinguish between the two accordingly. For example, while a user's finger touch may be operative to steal some of an electric field generated by a transmit signal, a harmonic generated by front tip stylus circuitry426aof stylus400amay be specifically different and unique, such that device100may be configured to detect and use such passive signal harmonics, for example, and also to reject any detected finger user touches, in order to determine an accurate location of stylus400a. For example, when front tip stylus circuitry426aincludes a single diode422a, a second harmonic of signal TS may be provided by front tip interface component421a, such that when a signal (e.g., signal TS) is transmitted by device100along I/O interface111awith a particular frequency (e.g., 150 kHz or 70 kHz or 40 kHz), device100may be configured to look for a signal (e.g., signal RS) with twice that particular frequency (e.g., 300 kHz or 140 kHz or 80 kHz), where the harmonic may be weaker than the signal at the fundamental frequency (e.g., about 20-25 db down from the signal level from a passive stylus), but unique, and with low background at that frequency. Therefore, when such a stylus400afor providing second harmonics may be known to be available to a user of device100, device100may be configured (e.g., via any suitable application and/or algorithm(s) or control circuitry for handling I/O interface111a) to look for a second harmonic of signal TS by signal RS for determining the location of stylus400a, where the amount of second harmonic that may be detected for each row or node111anmay depend on how close that row or node may be to front tip interface component421aof stylus400a. Signal TS may be transmitted as any suitable signal, such as a sinusoid shaped signal or a trapezoid shaped signal or any other suitably shaped signal whose non-linear distortion or harmonics of any suitable order may be detectable efficiently and/or effectively by any suitable control application(s) and/or algorithm(s) of device100.

Device I/O interface control of I/O interface111afor identifying and locating such a stylus400amay be specifically configured or tuned for that particular type of stylus, such that it may be effectively operative to initially identify and roughly locate the location of such a stylus (e.g., by effectively enabling rejection of other types of touch detection (e.g., user finger touch)), such as through detection of a non-linear distortion of the transmitted signal or one or more second harmonic signals (e.g., to a pixel or node pitch distance), and then the control (e.g., one or more algorithms or applications) may be configured to switch to a mode specific to that type of detected stylus (e.g., across sensor layer110bor within a particular radius of the initially detected position of the stylus (e.g., for better jitter performance)). For example, an algorithm may be configured to sense for a particular harmonic of a stylus for a particular transmitted signal, and once detected, more intense and/or frequent and/or focused scans may be utilized to detect that particular harmonic along the I/O interface (e.g., as part of a normal scan, attempt to detect a particular harmonic of a particular expected stylus, and then when that particular harmonic is detected, ramp up the scan features to track that particular stylus (e.g., a type of signal driving may be updated (e.g., only traces around the initially detected position of the stylus may be driven (e.g., to reduce signal to noise))).

At least one non-linear electrical element or load or rectifier, such as at least one diode422a, of non-linear electrical circuitry423athat may be electrically coupled to front tip interface component421amay enable stylus400ato be identified and distinguished from nearby user touches, dragging fingers, palm rests, and/or the like, due to a non-linear load that may generate a non-linear distortion or harmonics (e.g., a second harmonic) at touch pixels near the stylus tip. Each non-linear electrical element may be configured with any suitable characteristics. For example, diode422amay be provided with any suitable characteristics, such as a low capacitance (e.g., low parasitic capacitance), low reverse leakage, and/or low turn on voltage diode. The junction capacitance of such a diode may be configured to be low (e.g., less than 1.0 picofarad and/or less than 50 femtofarads). A reverse leakage current of such a diode may be controlled to be not too high. A Schottky diode, two or more Schottky diodes in series, or a specifically designed diode may be best suited for such a use. In some embodiments, as shown, circuitry426amay also include (e.g., in parallel with non-linear electrical circuitry423a) any suitable resistance circuitry425a(e.g., at least one resistor424a) for any suitable function, including, but not limited to, controlling reverse leakage current of non-linear electrical circuitry423aand/or preventing direct current (“DC”) positive voltage build up at the diode by effectively draining off any DC while maintaining non-linearity of circuitry426a. The resistance of resistance circuitry425a(e.g., resistor424a) may be selected in any suitable manner, such as by using a model of the panel, including its stimulation voltage and capacitance to the tip, and the non-linear device model, and optimizing the model. For an embodiment using one or more Schottky diodes for non-linear electrical circuitry423a, the optimum may vary, for example, between 4.0-6.0 megohms, or even no additional leakage may be needed.

At least one non-linear electrical element of non-linear electrical circuitry423a, such as diode422a, may be used to modulate and rectify a voltage on front tip interface component421aand may provide a load (e.g., a capacitance of front tip interface component421a(e.g., effectively)) and resistance circuitry425a, such as resistor424a, may be used to discharge the capacitance and/or to prevent capacitance from charging up. A high performance and/or low capacitance and/or low voltage Schottky diode (e.g., on an insulating substrate) may be useful for providing such a diode (e.g., diode422aand/or any other appropriate diode described herein), where such a diode may be made of any suitable material(s), including, but not limited to gallium arsenide and/or titanium nitride, which may have a large reverse leakage, but such leakage may be appropriately handled by resistance circuitry (e.g., resistance circuitry425a). In some embodiments, a diode would be useful if it were configured to have a current-voltage characteristic (e.g., an I-V curve) with certain properties, including, but not limited to, one with an abrupt or substantially abrupt non-linearity at some voltage and one that may maintain that voltage by balancing the forward and reverse characteristics. To produce a certain reverse voltage, the diode may be configured with an I-V curve where current may be sufficient to leak out the current pushed into the diode on the forward voltage and/or to keep an operating point in a region that is non-linear. One or more certain materials may be used to provide such a diode with such performance characteristics. Alternatively or additionally, a particular diode may be radiation damaged such that the diode may be operative to leak during use in a stylus, which may obviate any need for resistance circuitry (e.g., resistance circuitry425a). For example, a diode that has a constant reverse current rather than one that is modulated with a first harmonic may provide a useful result and/or may allow for a stylus without resistance circuitry (e.g., resistance circuitry425a), thereby reducing the number of components of the stylus. Additionally or alternatively to radiation damaging a diode for use in a stylus, the diode may be processed in any other suitable manner(s), including, but not limited to, heat processing or damaging and/or radiation processing or damaging in order to configure the diode to perform in an effective manner, such as to increase or change the reverse leakage of the diode (e.g., increase reverse leakage independently of a reverse voltage).

Resistance circuitry of non-linear electrical circuitry of a stylus (e.g., resistance circuitry425aof non-linear electrical circuitry423aof stylus400a) may include one or more resistors or may not be provided at all (e.g., when a diode with effectively increased reverse leakage is utilized). Alternatively, such resistance circuitry may include or be provided by any suitable current limiting device, which may be seen as a constant current source. This may be accomplished by providing any suitable current limiting field-effect transistor (“FET”) (e.g., an n-type metal-oxide-semiconductor (“NMOS”) device or depletion mode device) rather than a resistor. Such a device may be configured not to have a gate, but may include SiO2 or any other suitable element above a dope channel (e.g., a slightly n-type element), for example, such that the total amount of current that flows therethrough may be about 1 microAmpere. This may provide a flat region, such that when the circuitry goes to a high voltage, the channel may disappear. Therefore, in some embodiments, tip stylus circuitry, such as tip stylus circuitry426a, may be generated as a single chip (e.g., through very-large-scale integration (“VLSI”)) that may include a diode (e.g., Schottky diode) and a current limiting FET (e.g., a diode connected depletion mode device (e.g., a device with a gate connected to the drain of the MOSFET), where a diode connected FET may provide the diode action as well as the constant current backward leakage of the tip stylus circuitry).

Although only one diode422amay be shown as provided by non-linear electrical circuitry423a, it is to be understood that any suitable other number of non-linear electrical elements may be provided by non-linear electrical circuitry423a, which may be of the same type or different type of non-linear electrical element from one another. For example, two diodes may be electrically coupled in series (e.g., an anode of a first diode may be directly electrically coupled to body stylus circuitry427a, while the cathode of that first diode may be directly electrically coupled to an anode of a second diode, while the cathode of that second diode may be directly electrically coupled to front tip interface component421aof stylus400a). For example, two or more diodes (e.g., three diodes as shown inFIG. 6) may be coupled in series (e.g., with the anode of a first diode coupled to the cathode of a second diode, etc.) to create an asymmetric (e.g., top to bottom) waveform, and that may provide a second harmonic. However, compared to only a single diode (see, e.g.,FIG. 2B), multiple diodes provided in series (see, e.g.,FIG. 6) may be operative to reduce the parasitic capacitance across the combination. In other words, two or three diodes in series may look electrically like a single diode (e.g., operative to enable extraction of same harmonic by device100(e.g., second harmonic)), but with lower capacitance across them. The forward voltage drop across the diodes may also increase, but the reduction in parasitic capacitance may be more significant and/or effective. For example, the parasitic capacitance across two diodes in series may be half that of one diode, but with twice the forward voltage drop. If the drive waveform is configured to be symmetric in voltage (e.g., a square wave, sinusoidal wave, or trapezoidal wave), then there may be no second harmonic in the original field, and a single diode or diode pair connected in the same direction (e.g., if two diodes are coupled in series, such as with the anode of the first diode coupled to the cathode of the second diode) may be provided by non-linear electrical circuitry423ato create an asymmetric (e.g., top to bottom) waveform, and that may provide a second harmonic. A square or trapezoidal stimulation may have all of the odd harmonics, including the third harmonic, in the transmitted field, so it may be preferred to generate a second harmonic from the diode or non-linear electrical circuitry423a. A sinusoidal drive may not have any third harmonic, so back to back diodes or other symmetric non-linear electrical circuitry423acould be used, which may generate odd harmonics that could be detected. In some embodiments where back to back diodes or other symmetric non-linear electrical circuitry is used, resistance circuitry of such non-linear electrical circuitry may not be provided or utilized (e.g., as one diode may conduct in a forward direction and one may conduct in a backward direction).

As another example, two or more diodes may be electrically coupled in parallel (e.g., an anode of a first diode may be directly electrically coupled to body stylus circuitry, while the cathode of that first diode may be directly electrically coupled (or via a switch) to a tip interface component, and a cathode of a second diode may be directly electrically coupled to body stylus circuitry, while the anode of that second diode may be directly electrically coupled (or via a switch) to the tip interface component (see, e.g.,FIG. 4)). Such parallel diodes may be operative to configure the tip stylus circuitry (e.g., tip stylus circuitry426cofFIG. 4) to generate third harmonics of the transmitted signal (e.g., as opposed to second harmonics when only one diode is provided within the non-linear electrical circuitry), and device100may be configured to detect and handle such third harmonics in a different manner than other harmonics of other stylus types.

The direction (e.g., forward direction) of a non-linear electrical element, such as at least one diode422a, of non-linear electrical circuitry423awith respect to front tip interface component421aof stylus400amay be any suitable direction. For example, as shown inFIGS. 2-2C, anode A of diode422amay be directly electrically coupled to body stylus circuitry427a, while cathode C of diode422amay be directly electrically coupled to front tip interface component421aof stylus400a. Alternatively, in other embodiments, anode A of diode422amay be directly electrically coupled to front tip interface component421a, while cathode C of diode422amay be directly electrically coupled to body stylus circuitry427a. In either embodiment, the order of the harmonics generated by front tip stylus circuitry426awith only diode422awithin non-linear electrical circuitry423amay be second harmonics, although the phase or polarity of such harmonics may be different between those two embodiments, as may be detected by the projective capacitance circuitry of I/O interface111a. Therefore, both embodiments may be utilized by the same or different stylus to enable two different stylus types to be located by I/O interface111a, where each stylus type may be associated with one or more specific input characteristics. For example, a tip interface component of a stylus that provides second harmonics with a first phase may be determined by device100to have a first stylus identity, while a tip interface component of a stylus that provides second harmonics with a second phase different than the first phase may be determined by device100to have a second stylus identity different than the first stylus identity, and different stylus identities may be handled by device100in any suitable one or more different ways. For example, processor102may utilize a specific detected stylus identity (or an absence thereof) in any suitable manner including, but not limited to, accepting or rejecting input from a particular stylus, accepting input from multiple styli and/or from a single stylus, permitting or denying access to a particular functionality of the electronic device, applying a particular stylus profile, restoring one or more settings of the electronic device, notifying a third party that the stylus is in use, applying a setting to the electronic device, applying a setting to a program operating on the electronic device (e.g., which may include updating a user interface on display112aor otherwise of device100), changing a line thickness, color, pattern, erasure, and so on of a graphical object to be rendered by a graphics program of the electronic device, changing a setting of a video game operating on the electronic device, and so on. As shown inFIG. 2C, for example, single stylus400amay be provided with two different tip interface components for providing two different stylus identities. For example, as shown, anode A of diode422aof non-linear electrical circuitry423aof front tip stylus circuitry426amay be directly electrically coupled to body stylus circuitry427a, while cathode C of diode422amay be directly electrically coupled to front tip interface component421aof stylus400a, and, conversely, an cathode C of a diode432aof non-linear electrical circuitry433aof rear tip stylus circuitry436amay be directly electrically coupled to body stylus circuitry427a, while an anode A of diode432amay be directly electrically coupled to rear tip interface component431aof stylus400a, such that front tip interface component421amay provide second harmonics with a first phase while rear tip interface component431amay provide second harmonics with a second phase. Alternatively, a first number of diodes (e.g., 1) may be provided by non-linear electrical circuitry423aof front tip stylus circuitry426a, while a second, different number of diodes (e.g., 2) may be provided by non-linear electrical circuitry433aof rear tip stylus circuitry436a(e.g.,2diodes in parallel, as shown by circuitry423cofFIG. 4), such that front tip interface component421amay provide second harmonics while rear tip interface component431amay provide different (e.g., third) harmonics. Therefore, device100may be configured to determine whether user U may be moving front tip interface component421aof stylus400aalong I/O interface111a(e.g., atFIGS. 2A and 2B) or rear tip interface component431aof stylus400aalong I/O interface111a(e.g., atFIGS. 2D and 2E), such that device100may be configured to handle the detection of those different tip interface components in different manners. For example, device100may be configured to utilize the detection of front tip interface component421afor enabling generation of a drawing object (e.g., a graphical line) and to utilize the detection of rear tip interface component431afor enabling generation of an erasure object (e.g., removal of any graphical content), such that stylus400amay be utilized within system1similarly to a physical pencil that may have a drawing tool on one end and an erasure tool on another end. Although, it is to be appreciated that device100may be configured to handle different stylus identifies in any suitable different manners. In some embodiments, different tip interface components (e.g., on opposite ends of the same stylus or on different fingers of a glove or on different styli or accessories altogether) may include different bleed resistors (e.g., different resistance circuitries of the different tip interface components). As the bleed resistor is changed, the timing of the second harmonic may change, and may be detectable as a relative phase change of the second harmonic relative to the first harmonic. One use for such phase change detection may be to use a force sensitive resistor to change the resistance, thus, for example, enabling a tip force to be estimated (e.g., as may be described with respect to circuitry426cof stylus400cofFIG. 4).

Therefore, stylus400amay be configured to operate as a semi-passive and/or non-linear stylus. A semi-passive stylus may be a stylus without an active transmitter, such as a stylus that may be configured to react to the incident field but that may not be a simple linear probe like a user's finger or a conductive rod. Stylus400amay be provided at a very low cost, as it may not require any internal power source and may not require any direct coupling or communication of any wired/wireless communication interface data56with device100. Stylus400amay provide improved performance over a passive stylus on a projected capacitance input device by being able to be distinguished from direct user touch events (e.g., unintentional user touch events). Non-linearity of stylus400amay double (or otherwise provide any suitable multiple of) a modulation frequency (e.g., a fundamental frequency) of a transmitted signal TS (e.g., from 200 kHz to 400 kHz (see, e.g.,FIG. 6D, from a first harmonic671to a second harmonic673)) such that many cycles of non-linearity may be detected, such that noise may be reduced by requiring detection of a harmonic multiple times within multiple cycles or just once in a single cycle.

In addition to use with I/O interface111awhen configured to provide mutual capacitance sensing, stylus400amay also be configured to be used with I/O interface111awhen configured to provide self-capacitance sensing. For example, as shown inFIGS. 2F and 2G, when providing self-capacitance sensing, each pixel or pad of an array of I/O interface111a(e.g., first pad111ap1and second pad111ap2) may be driven by its own signal TS of its own transmitter circuitry T and an effected signal RS may be detected by any suitable receiver circuitry R. In the environment of self-capacitive sensing, the current taken to drive the pixels may be a non-linear function of the voltage driven, and can thus be distinguished from linear effects, such as a nearby finger or palm. Self-capacitive sensing may be combined with mutual capacitive sensing, for example, by driving a voltage on an electrode and monitoring both the current into that node and current into nearby nodes that are held at a voltage.

Another stylus400b, as shown inFIGS. 3-3Cmay include stylus I/O circuitry411bthat may include body stylus circuitry427bthat may be electrically coupled to front tip stylus circuitry426band/or to rear tip stylus circuitry (not shown). Body stylus circuitry427bmay be any suitable circuitry that may be operative to be electrically coupled (e.g., capacitively coupled) to user U when user U is holding stylus400babout at least a portion of body portion417b. As shown inFIG. 3, for example, body stylus circuitry427bmay be at least one conductive wire extending along at least a portion of a length of body portion417bof stylus400b, which may be insulated by any suitable insulation428b. Alternatively, body stylus circuitry427bmay be provided by a conductive (e.g., copper) tape along a portion of body417b, where such tape may be positioned under any suitable insulation, such as a finger pad of any suitable material. Any suitable housing401bmay be provided to protect body stylus circuitry427b, such as a plastic housing. In some embodiments, such a housing may be operative to provide insulation428b. Additionally or alternatively, at least a portion of body stylus circuitry417bmay be at least partially exposed via housing401band/or insulation428bfor enabling direct contact by user U. When user U is holding stylus400babout and/or along a portion of body417b, a capacitance or user-handle capacitor UHC may be inherently formed (e.g., as shown inFIG. 3C). The capacitance of user-handle capacitor UHC may be large enough to pass the desired signal from the tip, but not so large as to allow large transients from electrostatic discharge events to pass. For example, the capacitance of user-handle capacitor UHC may be any suitable capacitance, such as a capacitance in the range of 1.0 picofarad to 10.0 picofarads.

Stylus I/O circuitry411bmay include a front tip interface component421bthat may provide at least a portion of front tip portion415b. Front tip interface component421bmay be the portion of stylus400bconfigured to directly interface with device I/O interface111a. For example, front tip interface component421bmay be formed from any suitable material, including, but not limited to, silicone, rubber, fluoro-elastomer, plastic, nylon, conductive or dielectric foam, metal (e.g., brass (e.g., a brass ball with a dielectric coating (e.g., a thin coating with a high dielectric constant))), or any other suitable material or combination of materials. In this manner, drawing of front tip interface component421bacross input surface110amay not cause damage to input surface110aor layers applied to input surface110a, such as, but not limited to, anti-reflective coatings, oleophobic coatings, hydrophobic coatings, cosmetic coatings, ink layers, and the like. Front tip interface component421bcan be configured to be removably attached to body417b, such as via threadings/screws, detents and/or recesses, interference-fit or snap-fit, and/or magnetic attraction, and/or the like, and electrically coupled capacitively, such as through a pogo-pin, spring, and/or the like. Transit of any stylus electric field may be provided from front tip interface component421band not from other portions of stylus I/O circuitry411b. Like component421a, front tip interface component421bmay be any suitable shape, such as a sphere or hemisphere, of any suitable size. For example, in some particular embodiments, front tip interface component421bmay be provided as a ball (e.g., a solder ball and/or brass ball) of any suitable diameter, such as 2 millimeters in diameter. Front tip interface component421bmay be configured to provide the same footprint area (e.g., tip field intersection area (e.g., of charge)) on input surface110ano matter the angle of axis120with respect to a plane of input surface110a. The size of front tip interface component421bmay be made as small as possible to enable precise localization of front tip portion415bwith respect to device I/O interface111a.

Front tip stylus circuitry426bmay be positioned between and electrically coupled to each one of front tip interface component421band a portion (e.g., a front end) of body stylus circuitry427b. Front tip stylus circuitry426bmay be configured as any suitable circuitry that may be operative to modulate a capacitance (e.g., an effective capacitance) at front tip interface component421bwhen user U is holding body417bof stylus400bsuch that front tip interface component421bof stylus400bmay be stimulated by a device stimulus that may be generated by device I/O circuitry of device I/O interface111aof electronic device100. For example, front tip stylus circuitry426bmay include any suitable switch circuitry423bthat may be electrically coupled (e.g., in series) between front tip interface component421band body stylus circuitry427b. Switch circuitry423bmay include any suitable number of any suitable type(s) of switch element(s)422b, such as a high impedance switch, such as a field-effect transistor (“FET”) (e.g., a metal-oxide-semiconductor field-effect transistor (“MOSFET”)). Additionally, as shown, front tip stylus circuitry426bmay include any suitable microcontroller402bpowered by any suitable power supply408b(e.g., a low frequency, very low power battery operated circuit) for switching switch element(s)422bbetween an open state where front tip interface component421band body stylus circuitry427bare not electrically coupled and a closed state where front tip interface component421band body stylus circuitry427bare electrically coupled by switch element422b. Microcontroller402bmay be configured (e.g., programmed) to switch (e.g., open or close) switch element422baccording to a particular pattern (e.g., a micro application403b) or according to a selected one of two or more patterns that may be implemented by microcontroller402b. Front tip stylus circuitry426bmay be provided as a very low power circuit that may modulate the effective capacitance TC of front tip interface component421bof stylus400baccording to a particular pattern. Front tip interface component421bmay be configured to have adequate effective capacitance for passive location using projective capacitance, such as, for example, an effective capacitance of 200 femtofarads or any other suitable magnitude. In some embodiments, rather than being powered by power supply408blocal to stylus400b, controller402bmay be powered by any suitable external stimulation (e.g., device I/O circuitry and/or a user holding the stylus).

One, some, or each available pattern may be operative to enable device100to distinguish stylus400bfrom a direct user touch event (e.g., by a finger or palm event by user U on I/O interface111a), as a pattern may be detected by receive signal RS at one or more nodes111an(e.g., ofFIG. 3Afor mutual capacitance) or pads Map (e.g., pad111ap3ofFIGS. 3B and 3Cfor self-capacitance) in response to transmitted signal TS being effected by the pattern-modulated effective capacitance of front tip interface component421b, where that pattern may be a pattern that may not be replicated by user U on its own (e.g., without front tip stylus circuitry426b). As an example, an exemplary pattern may be a Barker sequence followed by a digital code, where only the bits in the trailing digital code may change. A reason to have a low frequency pattern may be to minimize the power used by the switching circuit. Therefore, stylus400bmay be provided as a low power, semi-permanent battery, switched stylus. No other circuitry may be provided by stylus400b, such that it may be made at a low cost and with a very low powered battery that may be configured to enable stylus400bto function properly for many years without replacement. In some embodiments, the battery may be configured for any suitable duration of use, such as in a range of 5-50 milliamp hours. In some embodiments, any suitable input component may also be provided by stylus400bto enable user U to select a particular one of many patterns that may be available to front tip stylus circuitry426b, such that a particular pattern may be detected by device100and a particular functionality may be carried out by device100that may be associated with that particular pattern (e.g., device100may be configured to utilize the detection of front tip interface component421bwith a first pattern-modulated effective capacitance for enabling generation of a red drawing object (e.g., a red graphical line) and to utilize the detection of front tip interface component421bwith a second pattern-modulated effective capacitance for enabling generation of a green drawing object (e.g., a green graphical line), such that stylus400bmay be utilized within system1similarly to a physical multi-colored pen that may selectively output one of various ink colors. Although, it is to be appreciated that device100may be configured to handle different patterns as different stylus identifies in any suitable different manners.

Device I/O interface control of I/O interface111afor identifying and locating such a stylus400bmay be specifically configured or tuned for that particular type of stylus and/or one, some, or each pattern available to that stylus, such that it may be effectively operative to initially identify and roughly locate the location of such a stylus (e.g., by effectively enabling rejection of other types of touch detection (e.g., user finger touch or other patterns)), such as through detection of a particular pattern, and then the control (e.g., one or more algorithms or applications) may be configured to switch to a mode specific to that type of detected stylus (e.g., across sensor layer110bor within a particular radius of the initially detected position of the stylus (e.g., for better jitter performance)). For example, an algorithm may be configured to sense for a particular pattern of a stylus for a particular transmitted signal, and once detected, more intense and/or frequent and/or focused scans may be utilized to detect that particular pattern along the I/O interface (e.g., as part of a normal scan, attempt to detect a particular pattern of a particular expected stylus, and then when that particular pattern is detected, ramp up the scan features to track that particular pattern (e.g., a type of signal driving may be updated (e.g., only traces around the initially detected position of the stylus may be driven (e.g., to reduce signal to noise))). In an embodiment where a pattern may be a Barker sequence followed by a digital code, the Barker sequence itself and the detection thereof may not need to change.

Therefore, stylus400bmay be configured to provide a switch that may be modulated at a relatively low frequency, and/or that may be driven by a low power circuit that may be similar to that of an electronic watch, while a projective capacitive input device of I/O interface111amay be configured to seek and/or detect a signal modulated by a changing load of stylus400b(e.g., using a matched filter). Stylus400bmay be a very low-power, semi-permanent battery powered stylus that may be provided at a very low cost, as it may not require a substantial internal power source and may not require any direct coupling or communication of any wired/wireless communication interface data56with device100. Stylus400bmay provide improved performance over a passive stylus on a projected capacitance input device by being able to be distinguished from direct user touch events (e.g., unintentional user touch events). Although not shown, single stylus400bmay be provided with two different tip interface components, like stylus400a, for providing two different stylus identities. For example, switch circuitry423bof front tip stylus circuitry426bmay be operative to generate a first pattern, while switch circuitry of a rear tip stylus circuitry may be operative to generate a second pattern different than the first pattern. Additionally or alternatively, an input component of stylus400bmay be operative to adjust the type of pattern generated by its switch circuitry from a first pattern to a second pattern different than the first pattern.

Yet another stylus400c, as shown inFIG. 4, for example, may be similar to stylus400a, except as described herein. As shown, stylus400cmay include stylus I/O circuitry411cthat may be similar to stylus I/O circuitry411aand may be operative to be stimulated only by external stimulus, such as a device stimulus that may be generated by device I/O circuitry of device I/O interface111aof electronic device100and/or by user U when holding stylus400c, whereby that stimulation of stylus I/O circuitry411cmay be operative to enable stylus I/O circuitry411cto provide any suitable stylus electric field that may then be detected by device100for estimating the location of stylus400c. Stylus400cmay include a barrel or handle or body portion417cextending between a front tip portion415cand a rear tip portion (not shown), where body portion417cmay be configured to be held by user U as the user may slide a tip portion of stylus400cacross input surface110aof device I/O interface111aof device100.

Stylus I/O circuitry411cmay include body stylus circuitry427cthat may be electrically coupled to front tip stylus circuitry426cand/or to rear tip stylus circuitry (not shown). Body stylus circuitry427cmay be any suitable circuitry that may be operative to be electrically coupled (e.g., capacitively coupled) to user U when user U is holding stylus400cabout at least a portion of body portion417c. As shown inFIG. 4, for example, body stylus circuitry427cmay be at least one conductive wire extending along at least a portion of a length of body portion417cof stylus400c, which may be insulated by any suitable insulation428c. Alternatively, body stylus circuitry427cmay be provided by a conductive (e.g., copper) tape along a portion of body417c, where such tape may be positioned under any suitable insulation, such as a finger pad of any suitable material. Any suitable housing401cmay be provided to protect body stylus circuitry427c, such as a plastic housing. In some embodiments, such a housing may be operative to provide insulation428c. Additionally or alternatively, at least a portion of body stylus circuitry427cmay be at least partially exposed via housing401cand/or insulation428cfor enabling direct contact by user U. When user U is holding stylus400cabout and/or along a portion of body417c, a capacitance or user-handle capacitor (e.g., UHC (not shown inFIG. 4)) may be inherently formed. The capacitance of such a user-handle capacitor may be relatively large compared to a panel to tip capacitance (e.g., electric field response capacitances (e.g., capacitances SDC) between front tip interface component421cand each one of array trace row111arand array trace column111acof one or more nodes111anproximate front tip interface component421cwhen stylus400cis used with device100), but not so large that electrostatic discharges would be likely to damage the device. Stylus I/O circuitry411cmay include a front tip interface component421cthat may provide at least a portion of front tip portion415c. Front tip interface component421cmay be the portion of stylus400cconfigured to directly interface with device I/O interface111a. For example, front tip interface component421cof stylus400cmay be similar to front tip component421aof stylus400a.

Front tip stylus circuitry426cmay be positioned between and electrically coupled to each one of front tip interface component421cand a portion (e.g., a front end) of body stylus circuitry427c. Front tip stylus circuitry426cmay be configured as any suitable circuitry that may be operative to provide a non-linear load between body stylus circuitry427cand front tip interface component421cwhen user U is holding body417cof stylus400csuch that front tip interface component421cof stylus400cmay be stimulated by a device stimulus that may be generated by device I/O circuitry of device I/O interface111aof electronic device100. For example, front tip stylus circuitry426cmay include any suitable non-linear electrical circuitry423cthat may be electrically coupled (e.g., in series) between front tip interface component421cand body stylus circuitry427c. Non-linear electrical circuitry423cmay include any suitable number of non-linear electrical sub-circuitries (e.g., in parallel), such as non-linear electrical sub-circuitry422c′ and/or non-linear electrical sub-circuitry432c′, each of which may include any suitable number and type(s) of non-linear electrical elements. For example, as shown, non-linear electrical sub-circuitry422c′ may include at least one diode422c, and non-linear electrical sub-circuitry432c′ may include at least one diode432c. One, some, or each diode of non-linear electrical circuitry423c(e.g., diode422cand/or diode432c) may be any suitable type of diode, such as a Schottky diode, a transistor in diode configuration (e.g., a diode connected transistor), and/or the like. In some embodiments, one or each non-linear electrical sub-circuitry of non-linear electrical circuitry423cmay include any suitable number (e.g., two or three or four or more) of diodes that may be coupled together in series (e.g., a cathode of one diode may be coupled to an anode of a next diode and/or the like). Alternatively, as shown, only a single diode may be provided by each non-linear electrical sub-circuitry, where an anode of diode422cmay be electrically coupled to body stylus circuitry427cand where a cathode of diode422cmay be electrically coupled to front tip interface component421cvia any suitable switch circuitry429c′ that may be electrically coupled (e.g., in series) between front tip interface component421cand non-linear electrical sub-circuitry422c′, and/or where a cathode of diode432cmay be electrically coupled to body stylus circuitry427cand where an anode of diode432cmay be electrically coupled to front tip interface component421cvia any suitable switch circuitry439c′ that may be electrically coupled (e.g., in series) between front tip interface component421cand non-linear electrical sub-circuitry432c′. Switch circuitry429c′ may include any suitable number of any suitable type(s) of switch element(s)429c, and switch circuitry439c′ may include any suitable number of any suitable type(s) of switch element(s)439c, where, for example, one, some, or each switch element may be a high impedance switch, such as a field-effect transistor (“FET”) (e.g., a metal-oxide-semiconductor field-effect transistor (“MOSFET”)) or any other suitable switch that may be controlled in any suitable manner (e.g., by a user input button (e.g., via aperture416) and/or any other suitable pressure or force or the like). Any switch of tip stylus circuitry426cmay be a force or pressure sensitive switch (e.g., a switch may close if more than a certain threshold amount of force is applied to the switch (e.g., switch429cmay be configured to be open unless at least 10 grams of force is applied thereto (e.g., unless a user presses tip interface component421cagainst device100with at least 10 grams of force) and/or switch439cmay be configured to be open unless at least 20 grams of force is applied thereto (e.g., unless a user presses tip interface component421cagainst device100with at least 20 grams of force) and/or the like). Additionally or alternatively, any switch of tip stylus circuitry426cmay be a mechanical switch that may be opened or closed by a user pressing or depressing a user interface button (e.g., via an aperture416) or via any other suitable user action.

Therefore, like stylus400a, stylus400cmay be operative to provide at least two different stylus identities. For example, due to diode422cbeing flipped with respect to diode432c, such that front tip interface component421cmay provide second harmonics with a first phase when switch429cis closed and when switch439cis open whereby diode422cbut not diode432cis electrically coupled between body stylus circuitry427cand front tip interface component421c, and/or such that front tip interface component421cmay provide second harmonics with a second phase different than the first phase when switch429cis open and when switch439cis closed whereby diode432cbut not diode422cis electrically coupled between body stylus circuitry427cand front tip interface component421c, and/or such that front tip interface component421cmay provide no second harmonics when each one of switches429cand439cis open whereby none of diodes422cand432cis electrically coupled between body stylus circuitry427cand front tip interface component421c. Alternatively, front tip interface component421cmay provide second harmonics when only one of switch429cand switch439cis closed and when the other one of switch429cand switch439cis open, whereby only a single one of diode422cand diode432cis electrically coupled between body stylus circuitry427cand front tip interface component421c, or front tip interface component421cmay provide different (e.g., third) harmonics when each one of switch429cand switch439cis closed, whereby each one of diodes422cand432cmay be electrically coupled between body stylus circuitry427cand front tip interface component421c, or front tip interface component421cmay provide no second harmonics or third harmonics when each one of switches429cand439cis open, whereby none of diodes422cand432cis electrically coupled between body stylus circuitry427cand front tip interface component421c. Therefore, device100may be configured to determine whether user U may be moving front tip interface component421cof stylus400calong I/O interface111awith only non-linear electrical sub-circuitry422c′ electrically coupled thereto by switch circuitry429c′, or with only non-linear electrical sub-circuitry432eelectrically coupled thereto by switch circuitry439e, or with each one of non-linear electrical sub-circuitry422c′ and non-linear electrical sub-circuitry432c′ electrically coupled thereto by switch circuitry429c′ and switch circuitry439e, or with no non-linear sub-circuitry electrically coupled thereto by any switch circuitry, such that device100may be configured to handle the detection of those different tip interface components in different manners. Therefore, use of one or more switching circuitries may be utilized to alter the stylus identity of tip interface component421cof stylus400c(e.g., between different harmonics and/or between different phases) rather than utilizing different tip interface components (e.g., as described above with respect to tip interface components421aand431aof stylus400a).

In some embodiments, as shown, circuitry426cmay also include (e.g., in parallel with non-linear electrical circuitry423c) any suitable resistance circuitry425c(e.g., at least one resistor424c(e.g., any suitable force-sensing resistor (e.g., as shown) or any other suitable resistor)) for any suitable function, including, but not limited to, controlling reverse leakage current of non-linear electrical circuitry423cand/or preventing DC positive voltage build up at the diode by effectively draining off any DC while maintaining non-linearity of circuitry426c. In some embodiments, such as similarly to resistance circuitry425aof stylus400a, the resistance of resistance circuitry425c(e.g., resistor424c) may be selected in any suitable manner, such as by using a model of the panel, including its stimulation voltage and capacitance to the tip, and the non-linear device model, and optimizing the model. For an embodiment using one or more Schottky diodes for non-linear electrical circuitry423c, the optimum may vary, for example, between 4.0-6.0 megohms, or even no additional leakage may be needed.

Any switch described herein as may be provided by any stylus or accessory may be provided in a handle portion, such as behind any diodes or resistors or non-linear electrical circuitry or tip stylus circuitry. Such a switch may be operative to break a DC path between them, which may effectively turn off non-linearity because a DC voltage may build up across the diode(s), and the reverse bias may not allow any current to flow. This may be used as a signal to (e.g., detectable by) the sensor circuitry of I/O interface111aof device100, or to “break” or lift the pen. Additionally or alternatively, this may be done with a switch that may turn on only when pressure is applied to the tip of the stylus/accessory, which may enable a “make/break” on force rather than on estimated Z-height (e.g., as mentioned herein).

Yet another accessory400d, as shown inFIG. 5, for example, may be similar to stylus400aor any other stylus of this disclosure, except as described herein. Accessory400dmay be configured with an accessory housing401dof any suitable structure, such as a glove, as shown, or any other accessory wearable or otherwise usable by a user for interacting with electronic device100. Accessory400dinclude accessory I/O circuitry411dthat may be similar to stylus I/O circuitry411aor stylus I/O circuitry411band may be operative to be stimulated by external stimulus, such as a device stimulus that may be generated by device I/O circuitry of device I/O interface111aof electronic device100and/or by user U when using accessory400d(e.g., when a user's hand is wearing glove accessory400d) and/or by a small power supply of accessory400d, whereby that stimulation of accessory I/O circuitry411dmay be operative to enable accessory I/O circuitry411dto provide any suitable accessory electric field that may then be detected by device100for estimating the location of accessory400d. Accessory400dmay include a hollow barrel or finger body portion417d(e.g., of a finger401dfof body401d) extending between a front tip portion415dand a rear tip (or open end) portion, where body portion417dmay be configured to be worn by user U (e.g., by or about or otherwise on a finger of the user) as the user may slide a tip portion of accessory400d(e.g., a fingertip portion that may electrically expose or otherwise be adjacent front tip interface component421dof accessory400d) across input surface110aof device I/O interface111aof device100.

Accessory I/O circuitry411dmay include body accessory circuitry427dthat may be electrically coupled to front tip accessory circuitry426d. Body accessory circuitry427dmay be any suitable circuitry that may be operative to be electrically coupled (e.g., capacitively coupled) to user U when user U is wearing accessory400d(e.g., body portion417dof finger401df) about a portion or against a portion (e.g., finger (e.g., fingertip)) of user U. As shown inFIG. 5, for example, body accessory circuitry427dmay be at least one conductive pad extending across a hollow of body portion417dof finger401dffor being contacted by a user's finger and/or a ring like conductive structure operative to be worn about a user's finger. Any suitable housing401dof any suitable material(s) may be provided to protect body accessory circuitry427d. When user U is wearing accessory400d, a capacitance or user-handling capacitor (e.g., UHC) may be inherently formed. The capacitance of such a user-handling capacitor may be relatively large compared to a panel to tip capacitance (e.g., electric field response capacitances (e.g., capacitances SDC) between front tip interface component421dand each one of array trace row111arand array trace column111acof one or more nodes111anproximate front tip interface component421dwhen accessory400dis used with device100), but not so large that electrostatic discharges would be likely to damage the device. Accessory I/O circuitry411dmay include a front tip interface component421dthat may provide at least a portion of front tip portion415d. Front tip interface component421dmay be the portion of accessory400dconfigured to directly interface with device I/O interface111a. For example, front tip interface component421dof accessory400dmay be similar to front tip component421aof stylus400a.

Front tip accessory circuitry426dmay be positioned between and electrically coupled to each one of front tip interface component421dand a portion (e.g., a front end) of body accessory circuitry427d. Front tip accessory circuitry426dmay be configured as any suitable circuitry (e.g., similar to circuitry426aand/or circuitry426c) that may be operative to provide a non-linear load between body accessory circuitry427dand front tip interface component421dwhen user U is wearing body417dof accessory400dsuch that front tip interface component421dof accessory400dmay be stimulated by a device stimulus that may be generated by device I/O circuitry of device I/O interface111aof electronic device100. Alternatively, front tip accessory circuitry426dmay be configured as any suitable circuitry that may be operative to function similarly to circuitry426band/or any other tip accessory circuitry described herein. Therefore, while the overall structure of accessory400dmay resemble a glove or any other suitable wearable accessory rather than a stylus, accessory400dmay be utilized similar to any stylus described herein.

As mentioned, and as further shown inFIGS. 6 and 6A, sensor layer110bof electronic device100may be configured to provide a matrix or array or grid of any suitable number of array trace columns111acand any suitable number of array trace rows111ar, any two of which may intersect to provide a sensing node. Array trace columns111acmay also be referred to herein as transmit electrodes, while array trace rows111armay also be referred to herein as receive electrodes. In some embodiments, each one of these transmit and receive electrodes may be formed, at least in part, from an optically transparent conductor, such as, but not limited to, metal oxides such as indium-tin oxide and antimony-tin oxide, nanowire patterns formed from silver nanowire, carbon nanotubes, platinum nanowire, gold nanowire, and so on, thin deposits of metal, and the like. Each transmit electrode may provide any suitable capacitance (e.g., Cjxd) and each receive electrode may provide any suitable capacitance (e.g., Cixs). As shown, the transmit electrodes may be provided in an array that may be orthogonal to the receive electrodes (e.g., below the receive electrodes) in a matrix, while the array or matrix of orthogonal transmit electrodes and receive electrodes of sensor layer110bmay be provided below or otherwise adjacent (e.g., etched into or layered on or otherwise positioned against) input surface input component110a(e.g., glass). It is to be understood that although various direction and orientational terms, such as “column” and “row,” and “X−” and “Y−” and “Z,” “up” and “down,” “front” and “back,” “left” and “right,” “upper” and “lower,” “top” and “bottom” and “side,” “above” and “below,” “vertical” and “horizontal” and “diagonal,” “length” and “width” and “thickness” and “diameter” and “cross-section” and “longitudinal,” and/or the like, may be used herein, such references are only for convenience, and that no fixed or absolute directional or orientational limitations are intended by the use of these words. If reoriented, different directional or orientational terms may need to be used in their description, but that will not alter their fundamental nature as within the scope and spirit of the subject matter described herein in any way. For example, while an “X-Y” layout may be referenced with respect to I/O component111a, a diagonal lattice layout, where there may be no dedicated X- or Y-elements, but where each element may be transmitting or sensing at different times during a scan of the touch screen, may be utilized for enabling use of any stylus or accessory described herein. Thus, references to the details of the described embodiments are not intended to limit their scope.

Any suitable electrical signal (e.g., transmit signal) TS, such as any suitable voltage waveforms (e.g., sinusoidal drive or trapezoidal voltages) (e.g., Vjstim), may be emitted or transmitted on one, some, or each transmit electrode by any suitable transmitter circuitry T of I/O interface111a(e.g., of sensor layer110b). Such a transmit signal TS may drive non-linear circuitry of a stylus (e.g., circuitry436a′ of stylus400a) that may be positioned on input surface110a, and such non-linearity may produce harmonics or any other suitable non-linear aspects of transmit signal TS. Any suitable electrical signal (e.g., receive signal) RS, such as any suitable sensed current (e.g., Iisense), may be detected by any suitable receiver circuitry R of I/O interface111a(e.g., of sensor layer110b) that may be provided along each one of the receive electrodes or that may be shared and used serially with two or more receive electrodes. As shown, receiver circuitry R may be any suitable circuitry, such as any suitable operational amplifier circuitry (e.g., a current sense amplifier (e.g., with feedback)) and an analog-to-digital converter (“ADC”) that may be operative to digitize a current or other signal that may be sensed on a receive electrode (e.g., receiver circuitry R may be operative to hold other electrodes at virtual ground and utilize a current to voltage amplifier and then digitize the voltage on the receive electrode). Then, any suitable digital signal processing (“DSP”) may be provided by processor102and any suitable application103running thereon in combination with the circuitry of I/O interface111a(e.g., circuitry T and circuitry R of sensor layer110b) in order to extract any non-linear aspects of the receive signal RS with respect to the transmit signal TS (e.g., to demodulate the second harmonic of a sine wave) and then to estimate a position of the stylus or accessory tip with respect to device100(e.g., X-Y location along the surface of input component110a) based on the extracted non-linear aspects.

For example, graph650ofFIG. 6Bmay be indicative of an exemplary plot over time of an exemplary transmit voltage, such as a voltage transmit signal TS that may be applied by circuitry T to a transmit electrode of sensor layer110bof I/O interface111a. Graph660ofFIG. 6Cmay be indicative of an exemplary plot over time of an exemplary tip voltage, such as a voltage receive signal RS that may be sensed by circuitry R as provided on a receive electrode of sensor layer110bof I/O interface111aby a tip of a stylus (e.g., tip431aof stylus400a(e.g., with non-linear circuitry436a′)) when the tip may be stimulated by the transmit voltage of graph650(if no tip is present, then the transmit electrode may be just a pure capacitance, and the current sensed may be reactively related through the capacitance, and may be out of phase but still similar to the transmit signal (e.g., sinusoidal, not asymmetrically distorted)). Graph670ofFIG. 6Dmay be indicative of an exemplary plot of an exemplary magnitude with respect to frequency of an applied voltage (e.g., voltage transmit signal TS of graph650) as sensed by a receive electrode (e.g., voltage receive signal RS of graph660), for example, as may be determined by the DSP of device100. For example, as shown, graph670may identify a fundamental frequency (e.g., first harmonic)671(e.g., at a frequency of 200 kHz (e.g., a fundamental frequency of transmit signal TS)) and a non-linear aspect (e.g., second harmonic)673(e.g., at a frequency of 400 kHz (e.g., a multiple of the fundamental frequency of transmit signal TS)). Therefore, the non-linearity of stylus400amay double (or otherwise provide any suitable multiple of) a modulation frequency (e.g., a fundamental frequency) of a transmitted signal TS (e.g., from 200 kHz to 400 kHz (see, e.g.,FIG. 6D, from a first harmonic671to a second harmonic673)) such that many cycles of non-linearity may be detected, such that noise may be reduced by requiring detection of a harmonic or any other suitable non-linear aspect multiple times within multiple cycles or just once in a single cycle. Depiction680ofFIG. 6Emay be indicative of any external element(s) determined (e.g., by DSP1 (e.g., DSP1@1×) of any suitable processing of device100) to be sensed on a surface of input component110abased on any fundamental frequency or first harmonic information (e.g., information of frequency671of graph670) for some or each receive electrode of the system, which, as shown, may be indicative of not only a stylus tip by depiction portion681but also a portion of a user's hand by depiction portion683, while depiction690ofFIG. 6Fmay be indicative of any external element(s) determined (e.g., by DSP2 (e.g., DSP2@2×) of any suitable processing of device100) to be sensed on a surface of input component110abased on any non-linear aspect or multiple (e.g., second) harmonic information (e.g., information of frequency673of graph670) for some or each receive electrode of the system, which, as shown, may be indicative of only a stylus tip by depiction portion691and not also a portion of a user's hand. This may create a unique identifier for a stylus with non-linear circuitry that may resolve certain location detection issues, such as disambiguation, merge, and negative pixel.

Therefore, one DSP per receive electrode demodulation path may be set to two-times the stimulation frequency (e.g., the frequency of the stimulation transmitted signal TS) in order to identify the location of a stylus with non-linear circuitry (e.g., circuitry providing a second harmonic), which may be used to only identify the location of the stylus and not a user that may not provide any non-linearity. Therefore, a transmitted signal (e.g., stimulation voltage (e.g., a pure tone or only with odd harmonics)) may be provided on one or more transmit electrodes to drive non-linear circuitry of a stylus that may produce at a stylus tip harmonic(s) or any other suitable non-linear aspect(s) of the transmitted signal (e.g., asymmetrical distortion due to a non-linear load (e.g., rectifier (e.g., diode))) that may be received as receive signal(s) on one or more receive electrodes and used through any suitable processing (e.g., DSP) to diagnose harmonics or non-linearity (e.g., by identifying non-linearity in a sense current spectrum (e.g., identifying that a sense current spectrum contains a second order harmonic)) to determine where a tip of the stylus may be located with respect to the electrodes.

FIG. 7is a flowchart of an illustrative process700for determining a location of a stylus with non-linear circuitry at an input component of an electronic device (e.g., stylus400awith non-linear circuitry423aat an input component110aof electronic device100). Process700may begin at operation710, where any suitable transmit signal or voltage waveform (e.g., transmit signal TS) may be emitted or otherwise provided by the electronic device on one, some, or each transmit electrode (e.g., each transmit electrode serially) in any suitable manner (e.g., in any suitable transmit pattern (e.g., the same stimulation waveform may be provided with one of two alternated phases (e.g., 0° or 180°) or not provided at all to different transmit electrodes in any suitable transmit pattern (e.g., according to any multi-stim matrix)). The transmit signal may include waveforms with little or negligible second harmonic or a known second harmonic. For example, the second harmonic may be low, such as about 50 db below the fundamental of the waveform. The transmit signal may be a sinusoidal waveform or a non-sinusoidal waveform. For example, a trapezoidal waveform may be generated or approximated by adding first harmonic and some amount of third harmonic and/or fifth harmonic, and/or the like to a sinusoidal waveform, which may not add to the voltage (e.g., Vmax) of the transmitted waveform but that may increase the fundamental of the waveform, which may increase the non-linear aspect (e.g., second harmonic) that may be generated and detected via a non-linear stylus (e.g., stylus400awith circuitry426a). Therefore, by adding odd harmonics (e.g., generating a waveform that may only have or may only substantially have odd harmonics), we may essentially drive a trapezoidal waveform that may provide a higher fundamental without a higher Vmax, which may obey certain system constraints while also increasing the non-linear aspect (e.g., second harmonic) of the transmit signal that may be detectable by the system through use of a stylus with non-linear circuitry.

At operation720, process700may include the electronic device holding other electrodes (e.g., receive electrodes) at virtual ground (e.g., with op amp circuitry (e.g., current to voltage amplifier)) and digitize (e.g., with an ADC) any current sensed (e.g., a receive signal RS) on the electrodes (e.g., on one, some, or each receive electrode). For example, any suitable receive circuitry R of sensor layer110bof I/O interface Ilia may be capacitively coupled to a node (e.g., a capacitive sensing node of the array of receive and transmit electrodes) and may use any suitable feedback circuitry to maintain at a constant voltage and/or at virtual ground and may then output a voltage (e.g., tip voltage) to an ADC. While the receive signal(s) RS sensed at operation720may generally be sensed on one or more receive electrodes, device100may additionally or alternatively be configured to monitor the current on the drive electrodes for determining one or more receive signals RS. For example, a current at a drive electrode may be measured that may include a harmonically driven portion or otherwise non-linearly or asymmetrically distorted portion when a stylus with non-linear circuitry is affecting one or more transmit signal(s) on one or more drive electrodes. At operation730, process700may include removing any correlated noise on the measured currents (e.g., the received signal(s) RS of the receive electrode(s) (and/or of the drive electrode(s)) of operation720).

At operation740, process700may include extracting (e.g., with the electronic device (e.g., using any suitable DSP) any suitable non-linear aspects of the measured current with respect to the transmitted waveforms. For example, operation740may include demodulating a second harmonic of a sinusoidal transmit signal TS of operation710from a current receive signal RS sensed at operation720. Operation740may include carrying out any suitable comparison of a sensed output current on a receive electrode with respect to an input voltage provided on a transmit electrode in order to identify a non-linear aspect (e.g., a second or third or other suitable harmonic or asymmetric distortion or non-linear distortion of the fundamental (e.g., of the transmit signal at the receive signal)). At operation750, it may be determined if all transmit patterns for a current time step have been carried out, and, if not, process700may return to operation710and once again carry out operations710-740for another transmit pattern for the current time step. However, if all transmit patterns for a current time step have been carried out, process700may proceed from operation750to operation760. In some embodiments, for a particular time step of device100, one, some, or each transmit electrode may be modulated (e.g., provided with a transmit waveform TS) one at a time and an output on one, some, or each receive electrode may be measured at operations710-750. Alternatively, to be more efficient, for a particular time step of device100, a correlated pattern (e.g., invertible Hadamard matrix) of transmit electrodes may be modulated (e.g., provided with a transmit waveform TS) and an output on one, some, or each receive electrode may be measured at operations710-750. However, generally, for a particular time step of device100, one or more transmit electrodes may be stimulated (e.g., serially or in various patterns) and receive signal data may be extracted from one or more receive electrodes (and/or drive electrodes) for use in identifying non-linear aspects for determining a location of a non-linear accessory or stylus during that particular time step. At operation760, process700may include estimating (e.g., using any suitable processing of device100) a position of a tip of an accessory on an input surface of the electronic device for a particular time step of the device using the measurements of operations710-740for the particular time step. At operation770, process700may include outputting (e.g., using any suitable processing of device100) an X-Y location estimation for the tip of the accessory for the particular time step, while process700may also return to operation710and repeat the process for a next time step of the device. Such an output X-Y location estimation for the accessory tip may be utilized (e.g., using any suitable processing and/or other component(s) of device100) in any suitable manner for carrying out or adjusting any suitable functionality of the system, such as for adding graphical object data to a presented display on device100or adjusting the position of a cursor on device100or selecting an option associated with a graphical object displayed by device100at that X-Y location and/or the like.

As just one example, operation760may include one or more sub-operations, such as operations761,763,765,767, and/or769. For example, operation761may include removing any suitable correlated noise across the receive electrodes (e.g., in addition to or as an alternative to the removal at operation730). For example, in a given time step, multiple receive electrodes may be receiving current or any other signal(s) that may be sensed at operation720, such that any or all noise that may be common mode or linearly related between those receive electrodes may be removed (e.g., as an effective procedure to improve signal to noise ratio). At operation763, any suitable non-linear residual may be estimated and removed from any suitable electronics of device100(e.g., any second harmonic of the fundamental that may be emitted by any electronics of device100that may interfere with the accuracy of process700). At operation765, the most likely position (e.g., X-Y location) of the tip from the given observed data (e.g., as observed earlier in process700for the particular time step (e.g., as may have been adjusted through removal of noise and residuals)) may then be estimated. At operation767, a signal strength of any signals of process700(e.g., the signal strength of any receive signals RS of operation720) may be extracted to determine the height of the tip from the surface of input surface110a. Such a determined height may be used by device100to determine whether or not the stylus is touching input surface110aor otherwise determine whether the position of the tip being estimated is a position intended to be identified as an intentional stylus input event (e.g., to determine if the stylus is intended to be used as an input device for drawing a line or if the stylus is not intended to be used as an input device but is rather lifted off the input surface and is being moved to a new location for a new input event). At operation769, the estimated position for the particular time step of operation765(e.g., if not to be disregarded due to an insufficient signal strength of operation767) may be temporally filtered using any suitable estimated positions from previous iterations of process700for previous time steps. For example, any suitable temporal filter may be configured to provide estimates for where a tip is for a particular time step that may be smoothed out based on earlier estimates for earlier time steps before presenting an estimated location for the current time step for use at operation770(e.g., before the estimate is presented to an operating system or specific stylus-position dependent application that may be running on device100).

Any suitable process(es) may be carried out (e.g., automatically by any suitable processing/application(s) of device100) in order to estimate the most likely position of the tip of the stylus. For example, the non-linear aspects and/or any other determined information from operations710-763for a particular time step may be compared to outputs of any suitable model for an array of various possible X-Y locations and then find the model output that compares most favorably to the data determined for the current time step (e.g., using best fit via a least squares method) and then using the X-Y location of that model output as the estimated location of the stylus tip for the current time step. Such a model may be generated in any suitable manner. For example, such a model may be a mathematical model built based on a physics model of capacitance to the tip of the stylus and based on a circuit simulator model (e.g., simulation program with integrated circuit emphasis (“SPICE”) model) of the electronic device. For example, such a physics model may utilize finite element analysis (“FEA”) to physically diagram the interaction between the stylus and the device in order to calculate the expected fields (e.g., location of tip to location of capacitance), which may include a calculation of capacitance between transmit and receive electrodes for every possible position of the stylus tip with respect to the device's input surface, while such a circuit simulator model may utilize circuitry information about the circuitry (e.g., any suitable non-linear elements) of device100and/or of the stylus. The combined mathematical model may then be utilized to generate various sets of outputs, where each set may be indicative of the receive signal RS expected to be received at each device electrode when the tip is at a respective one of the various possible X-Y locations along the device's input surface. Such sets of model outputs may then be compared to an actual set of outputs by the device as determined at operations710-763for a particular time step in order to determine the best fit model output set in order to use the X-Y position associated with that best fit model output set as the estimated most likely position of the stylus with respect to device100for that particular time step.

In some embodiments, a magnitude of the force or pressure exerted by the accessory tip on the input surface may be determined by the electronic device. For example, a phase angle between the fundamental of a transmit signal and a non-linear aspect of a sensed receive signal may be identified and used to determine an amount of pressure exerted by the stylus (e.g., when a signal is demodulated to extract a second harmonic, the in-phase and quadrature (“I&Q”) components and phase angle may be realized by such processing). For example, the resistance of resistance circuitry425cmay be selectively adjusted by a user during use of stylus400c, which may adjust voltage of tip voltage and/or the phase angle between the fundamental of the transmit signal and the non-linear aspect of the detected receive signal. For example, a strain sensitive or force-sensing or any other suitable resistor424cmay be provided by resistance circuitry425cthat may adjust the resistance of resistor424cbased on how much force or pressure is applied thereto. Therefore, a stylus may be configured such that an amount of force used by the user to press the stylus tip against an input surface of an electronic device may adjust the amount of resistance provided by resistance circuitry (e.g., resistance circuitry in parallel with non-linear circuitry of that stylus). Such resistance adjustment may adjust the voltage of a receive signal and/or the phase angle detected by the electronic device and may be used to estimate the amount of force used by the user and stylus, which may provide yet another input for affecting the functionality of device100(e.g., in addition to an estimated location of the stylus (e.g., such that location and force of the stylus may together be used to determine how the device adjusts a device functionality (e.g., draw a light green line at a location or draw a dark green line at the location))). As just one example, an output of the model described with respect to operation765may include a phase angle output that may then be associated with a force output or the model may include a force output based on a determined phase angle.

In some embodiments, selective or dynamic scanning may be utilized to make process700more effective and/or efficient. For example, from one or more previous iterations of process700for one or more previous time steps, a previous location of a stylus may be estimated, and such an estimated location may be used to selectively or dynamically limit the electrodes that may be used in a current iteration of process700for a current time step (e.g., to only transmit signal(s) on certain transmit electrodes that may be proximate to the earlier estimated location and/or to only sense receive signal(s) on certain receive and/or transmit electrodes that may be proximate to the earlier estimated location), which may speed up processing and/or reduce power consumption for such a process. Different modes of location detection may be used for different types of external inputs, such as direct user touch, stylus with non-linear circuitry (e.g., stylus400a), stylus with pattern generating circuitry (e.g., stylus400b), and/or the like. For example, as shown byFIG. 6, a first DSP1 may be used to detect fundamental information of any external element(s) that may be used to determine the location of a user and/or any stylus or accessory (see, e.g., depiction680ofFIG. 6E), while a second DSP2 may be used to detect non-linear information of any external element(s) that may be used to determine the location of a stylus or accessory with non-linear circuitry (see, e.g., depiction690ofFIG. 6F). Such different modes may be switched temporally such that each mode may be carried out for a single time step (e.g., in a time slice fashion). The detected location data for external element(s) that may be generated by each mode for a single time step (e.g., data of depiction680and data of depiction690) may be utilized together to provide one or more improved location estimates (e.g., for a stylus with non-linear circuitry) and/or to provide a more effective and/or efficient localization process. Additionally or alternatively, such temporally switched modes may allow for the concurrent detection of different styli during a single time step, such as by using a first mode to detect a first non-linear aspect (e.g., a second harmonic or a harmonic with a first phase) and by using a second mode to detect a second non-linear aspect (e.g., a third harmonic or a harmonic with a second phase).

It is understood that the operations shown in process700ofFIG. 7are only illustrative and that existing operations may be modified or omitted, additional operations may be added, and the order of certain operations may be altered. WhileFIGS. 6, 6A-6F, and7may be discussed generally with respect to second order harmonic extraction as a particular type of non-linear aspect that may be utilized for stylus localization, it is to be understood that any other suitable type of non-linear aspect may be detected and utilized according to process700, such as third order harmonic with respect to a stylus with non-linear circuitry providing two diodes in parallel, for example.

FIG. 8is a flowchart of an illustrative process800for using a stylus that may include non-linear circuitry at an input component of an electronic device (e.g., stylus400awith non-linear circuitry423aat an input component110aof electronic device100). Process800may begin at operation802, where an electrical signal may be transmitted from transmitter circuitry of the input component of the electronic device (e.g., signal TS). At operation804, the non-linear circuitry of the stylus may be stimulated with the transmitted electrical signal. At operation806, a non-linear load may be provided at the stylus based on the stimulating of operation804. At operation808, a harmonic of the transmitted electrical signal may be created at the input component of the electronic device based on the non-linear load provided at operation806. Then, for example, the created harmonic may be detected with the electronic device and, based on the detecting, a position of the stylus with respect to the input component may be determined.

It is understood that the operations shown in process800ofFIG. 8are only illustrative and that existing operations may be modified or omitted, additional operations may be added, and the order of certain operations may be altered.

FIG. 9is a flowchart of an illustrative process900for using a stylus that may include switching circuitry at an input component of an electronic device (e.g., stylus400bwith switching circuitry423bat an input component110aof electronic device100). Process900may begin at operation902, where an electrical signal may be transmitted from transmitter circuitry of the input component of the electronic device (e.g., signal TS). At operation904, the switching circuitry may be switched according to a pattern (e.g., concurrently with operation902). At operation906, based on the switching of operation904, the transmitted electrical signal may be modulated according to the pattern. Then, for example, the modulated electrical signal may be detected with the electronic device and, based on the detecting, a position of the stylus with respect to the input component may be determined.

It is understood that the operations shown in process900ofFIG. 9are only illustrative and that existing operations may be modified or omitted, additional operations may be added, and the order of certain operations may be altered.

FIG. 10is a flowchart of an illustrative process1000for detecting an accessory on an input surface of an input component of an electronic device that includes a matrix of a plurality of transmit electrodes and a plurality of receive electrodes (e.g., for detecting any accessory or stylus400-400don input surface110aof I/O component111athat includes an array of electrodes). Process1000may begin at operation1002, where a transmit signal may be transmitted on each transmit electrode of at least a subset of the plurality of transmit electrodes (e.g., a transmit signal TS may be transmitted by transmitter circuitry T of device100). At operation1004, a receive signal may be sensed on each receive electrode of at least a subset of the plurality of receive electrodes (e.g., a receive signal RS may be sensed by receiver circuitry R of device100). At operation1006, data indicative of a non-linear aspect of the transmit signal may be extracted from each sensed receive signal (e.g., as described with respect to operation740of process700), and, at operation1008, a position of the accessory on the input surface may be estimated based on the extracted data (e.g., as described with respect to operation760of process700).

It is understood that the operations shown in process1000ofFIG. 10are only illustrative and that existing operations may be modified or omitted, additional operations may be added, and the order of certain operations may be altered. Different transmit signals may be transmitted on different transmit electrodes of at least the subset at operation1002(e.g., at the same time or at different times), and data indicative of a non-linear aspect of those transmit signals may be extracted at operation1006from the sensed receive signals.

Moreover, the processes described with respect toFIGS. 1-10(e.g., any control applications and/or algorithms), as well as any other aspects of the disclosure, may each be implemented by software, but may also be implemented in hardware, firmware, or any combination of software, hardware, and firmware. They each may also be embodied as computer-readable code recorded on a computer-readable medium. The computer-readable medium may be any data storage device that can store data or instructions which can thereafter be read by a computer system. Examples of the computer-readable medium may include, but are not limited to, read-only memory, random-access memory, flash memory, CD-ROMs, DVDs, magnetic tape, and optical data storage devices (e.g., memory104ofFIG. 1). The computer-readable medium can also be distributed over network-coupled computer systems so that the computer readable code is stored and executed in a distributed fashion. For example, the computer-readable medium may be communicated from one electronic device to another electronic device using any suitable communications protocol. The computer-readable medium may embody computer-readable code, instructions, data structures, program modules, or other data in a modulated data signal, such as a carrier wave or other transport mechanism, and may include any information delivery media. A modulated data signal may be a signal that has one or more of its characteristics set or changed in such a manner as to encode information in the signal.

As mentioned, electronic device100may drive a display (e.g., display112a) with graphical data to display a graphical user interface (“GUI”). The GUI may be configured to receive touch input via input component(s)110aand/or110b. Embodied as a touch screen (e.g., with display112aas I/O component111a), I/O component111amay display the GUI. Alternatively, the GUI may be displayed on a display (e.g., display112a) separate from touch input component110. The GUI may include graphical elements displayed at particular locations within the interface. Graphical elements may include, but are not limited to, a variety of displayed virtual input devices, including virtual scroll wheels, a virtual keyboard, virtual knobs, virtual buttons, any virtual UI, and the like. A user may perform gestures (e.g., user fingers and/or with stylus400) at one or more particular locations on input component(s)110aand/or110b, which may be associated with the graphical elements of the GUI. In other embodiments, the user may perform gestures at one or more locations that are independent of the locations of graphical elements of the GUI. Gestures performed on input component(s)110aand/or110bmay directly or indirectly manipulate, control, modify, move, actuate, initiate, or generally affect graphical elements, such as cursors, icons, media files, lists, text, all or portions of images, or the like within the GUI. For instance, in the case of a touch screen, a user may directly interact with a graphical element by performing a gesture over the graphical element on the touch screen. Alternatively, a touch pad may generally provide indirect interaction. Gestures may also affect non-displayed GUI elements (e.g., causing user interfaces to appear) or may affect other actions of device100(e.g., affect a state or mode of a GUI, application, or operating system). Gestures may or may not be performed on input component(s)110aand/or110bin conjunction with a displayed cursor. For instance, in the case in which gestures are performed on a touchpad, a cursor (or pointer) may be displayed on a display screen or touch screen and the cursor may be controlled via touch input on the touchpad to interact with graphical objects on the display screen. In other embodiments, in which gestures are performed directly on a touch screen, a user may interact directly with objects on the touch screen, with or without a cursor or pointer being displayed on the touch screen.

Feedback may be provided to the user via bus114in response to or based on the touch or near touches on a touch input component110. Feedback may be transmitted optically, mechanically, electrically, via olfactory, acoustically, or the like or any combination thereof and in a variable or non-variable manner.

Many alterations and modifications of the preferred embodiments will no doubt become apparent to a person of ordinary skill in the art after having read the foregoing description, it is to be understood that the particular embodiments shown and described by way of illustration are in no way intended to be considered limiting. Thus, references to the details of the described embodiments are not intended to limit their scope.