PATENT DOCUMENT

Publication Number: US-10025401-B2
Application Number: US-201514848277-A
Country: US
Kind Code: B2

Title: Active stylus ring electrode

Abstract:
A ring electrode to determine the orientation of the stylus relative to the surface. The stylus can include a ring electrode configuration which can improve capacitive coupling between the ring electrode and the touch panel. The ring electrode configuration can include a ring electrode and ground ring, and ground plate. By varying the lengths of ring electrode, ground ring, ground plate, and the distance between these elements, the electric field emanating from the ring electrode can be tuned to optimize the capacitive coupling between the ring electrode and surface. In some examples, the ring electrode can include multiple sub-rings. In some examples, the ring electrode can comprise a crown shape including projections, each having a width that tapers to a minimum width along the length of the ring electrode.

Claims:
What is claimed is: 
     
       1. An apparatus comprising:
 a base formed of a non-conductive material; 
 a ring electrode formed of a conductive material and encircling the base; 
 a ground ring formed of the conductive material and encircling the base and separated from the ring electrode by a first distance; and 
 a ground plate formed of a second conductive material and separated from the ring electrode by a second distance;
 wherein the ring electrode is connected to a drive circuitry, the ground ring is connected to a reference potential, and the ground plate is connected to the reference potential. 
 
 
     
     
       2. The apparatus of  claim 1 , wherein at least a portion of the ring electrode is a hollow cylindrical shape having a first outer diameter, and wherein at least a portion of the ground electrode is a hollow cylindrical shape having the first outer diameter. 
     
     
       3. The apparatus of  claim 2 , wherein the ring electrode has a length greater than the first outer diameter of the ring electrode. 
     
     
       4. The apparatus of  claim 1 , wherein the ring electrode has a first length and the ground ring has a second length less than the first length. 
     
     
       5. The apparatus of  claim 4 , wherein the first distance between the ring electrode and ground ring is smaller than the first length of the ring electrode. 
     
     
       6. The apparatus of  claim 4  wherein the first length is in a range of 3 mm and 7 mm. 
     
     
       7. The apparatus of  claim 4  wherein the first distance is in a range of 3.5 mm and 6 mm. 
     
     
       8. The apparatus of  claim 4  wherein the second distance is in a range of 2 mm and 4 mm. 
     
     
       9. The apparatus of  claim 1  wherein the apparatus further comprises a first connector configured to couple the apparatus to a tip electrode of a stylus device. 
     
     
       10. The apparatus of  claim 1  wherein the ring electrode is configured to capacitively couple to a touch-sensitive surface, and the ring electrode is also configured to capacitively couple to the ground ring. 
     
     
       11. The apparatus of  claim 1  further comprising one or more first conductive traces coupled to the ring electrode, one or more second conductive traces coupled to the ground ring, wherein the first and second conductive traces are routed through the base. 
     
     
       12. The apparatus of  claim 11  further comprising one or more first vias configured to couple the first conductive traces to the ring electrode and one or more second vias configured to couple the second conductive traces to the ground ring. 
     
     
       13. The apparatus of  claim 12  wherein at least one of the one or more second vias has a circular shape with a second diameter which is larger than a length of the ground ring. 
     
     
       14. The apparatus of  claim 1  wherein the reference potential is a ground voltage. 
     
     
       15. An electrode for an active stylus, comprising:
 a plurality of hollow cylindrical sub-rings positioned parallel to one another along a length of the electrode;
 wherein each of the sub-rings is separated from adjacent sub-rings in a first direction by a respective separation distance and wherein each of the sub-rings is electrically connected to one or more of the adjacent sub-rings via one or more conductive traces disposed between the adjacent sub-rings such that each of the sub-rings of the electrode are at a same electrical potential; and 
 wherein a respective length of each sub-ring increases with each of the hollow cylindrical sub-ring along the length of the electrode in the first direction. 
 
 
     
     
       16. The electrode of  claim 15 , wherein the respective length of each sub-ring along the length of the electrode increases by a scaling factor. 
     
     
       17. The electrode of  claim 16 , wherein the scaling factor is in a range of 1.5 and 2.5. 
     
     
       18. The electrode of  claim 15 , wherein a separation distance between a first sub-ring and a second sub-ring adjacent in a first direction is equal to a length of the first sub-ring. 
     
     
       19. The electrode of  claim 15 , wherein each of the conductive traces in the electrode are formed on a same cylindrical contour and are situated at different angles with respect to a radial axis of the cylindrical contour. 
     
     
       20. The electrode of  claim 15 , wherein
 a surface area of a first half of the electrode is greater than a surface area of a second half of the electrode, wherein the first half of the electrode and second half of the electrode are of equal axial length and are defined by a plane orthogonal to a radial axis of the electrode. 
 
     
     
       21. An electrode for an active stylus, comprising:
 a hollow cylindrical ring portion; 
 a plurality of projections forming a crown shape;
 wherein each of the plurality of projections originates at the hollow cylindrical ring portion and extends from the hollow cylindrical ring portion along a length of the electrode toward a first end, and 
 wherein each of the plurality of projections has a maximum width at the hollow cylindrical ring portion which tapers to a minimum width at the first end of the electrode. 
 
 
     
     
       22. The electrode of  claim 21 , wherein
 each of the plurality of projections has a first length; and 
 the hollow cylindrical ring portion has a second length less than the first length. 
 
     
     
       23. The electrode of  claim 22 , wherein
 a ratio of the first length to the second length is in a range of 2:1 and 3:1. 
 
     
     
       24. The electrode of  claim 22 , wherein
 the first length is in a range of 2.5 mm and 4.5 mm, and 
 the second length is in a range of 0.5 mm and 2.5 mm. 
 
     
     
       25. An input device comprising:
 a body including a shaft portion and a tip portion; 
 a tip electrode at a distal end of the input device and disposed in the tip portion; 
 a ring electrode apparatus disposed in the tip portion distal to the tip electrode, wherein the ring electrode apparatus includes:
 a base formed of a non-conductive material; 
 a ring electrode formed of a conductive material and encircling the base; 
 a ground ring formed of the conductive material and encircling the base and separated from the ring electrode by a first distance; 
 a ground plate formed of a second conductive material and separated from the ring electrode by a second distance; 
 
 stimulation circuitry coupled to the ring electrode and configured to generate one or more stimulation signals.

Description:
FIELD 
     This relates generally to input devices for use with touch-sensitive devices and, more specifically, to the design of a ring electrode of an active stylus. 
     BACKGROUND 
     Many types of input devices are presently available for performing operations in a computing system, such as buttons or keys, mice, trackballs, joysticks, touch panels, touch screens and the like. Touch-sensitive devices, and touch screens in particular, are quite popular because of their ease and versatility of operation as well as their affordable prices. A touch-sensitive device can include a touch panel, which can be a clear panel with a touch-sensitive surface, and a display device such as a liquid crystal display (LCD) that can be positioned partially or fully behind the panel so that the touch-sensitive surface can cover at least a portion of the viewable area of the display device. The touch-sensitive device can allow a user to perform various functions by touching or hovering over the touch panel using a finger, stylus or other object at a location often dictated by a user interface (UI) being displayed by the display device. In general, the touch-sensitive device can recognize a touch or hover event and the position of the event on the touch panel, and the computing system can then interpret the event in accordance with the display appearing at the time of the event, and thereafter can perform one or more actions based on the event. 
     Styli have become popular input devices for touch-sensitive devices. In particular, use of an active stylus capable of generating stylus stimulation signals that can be sensed by the touch-sensitive device can improve the precision and control of the stylus. A stylus can have various orientations (e.g., azimuth angle and tilt angle) as it touches or hovers over a touch panel. Some styli can detect the orientation of the stylus and perform actions based on the stylus orientation. However, detecting the azimuth angle and tilt angle of an active stylus can be difficult (e.g., tilt inaccuracy and tilt jitter can result) when the active stylus is used at certain orientation angles. 
     SUMMARY 
     This relates to detection of an orientation, e.g., the azimuth angle and tilt angle, of a stylus relative to a surface. In an example, the orientation of a stylus relative to a contacting surface, e.g., a touch panel, can be detected by detecting a capacitance at one or more locations on the stylus relative to the surface, and then using the capacitance(s) to determine the orientation of the stylus relative to the surface. In some examples, the stylus can include a ring electrode configuration which can improve capacitive coupling between the ring electrode (used for orientation detection) and the touch panel. In some examples, the ring electrode configuration can include a cylindrical ring electrode connected to control circuitry and a ground ring connected to a reference potential, for example, ground. By varying the lengths of ring electrode, ground ring, and the distance between these elements, the electric field emanating from the ring electrode can be tuned to optimize the capacitive coupling between the ring electrode and surface. For example, the coupling between the cylindrical ring electrode and surface can be more uniform along the ring electrode, which can improve tilt accuracy and decrease tilt jitter, resulting in better stylus performance. In some examples, the ring electrode can include multiple sub-rings, with the respective length of each sub-ring increasing with each sub-ring along the length of the electrode away from the stylus tip. In some examples, the ring electrode can comprise a crown shape including projections, each having a width that tapers to a minimum width along the length of the ring electrode. In some cases, the surface area of the ring electrode at a portion (e.g., half of the ring electrode) proximate to the stylus tip can be less than the surface area of the ring electrode at a portion distal to the stylus tip. In some cases, the ring electrode base can include vias and can route writing from the tip electrode, ring electrode, and ground ring through the ring electrode base to control circuitry in the stylus. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIGS. 1A-1D  illustrate examples of systems with touch screens that can accept input from an active stylus according to examples of the disclosure. 
         FIG. 2  illustrates a block diagram of an example computing system that can receive input from an active stylus according to examples of the disclosure. 
         FIG. 3  illustrates an example touch screen including touch sensing circuitry configured as drive and sense regions or lines according to examples of the disclosure. 
         FIG. 4  illustrates an example touch screen including touch sensing circuitry configured as pixelated electrodes according to examples of the disclosure. 
         FIGS. 5A and 5B  illustrate a side view and a bottom view, respectively, of an exemplary stylus according to various examples of the disclosure. 
         FIG. 6  illustrates an example touch sensor panel configuration operable with the touch ASIC of  FIG. 2  to perform a stylus scan according to examples of the disclosure. 
         FIGS. 7A and 7B  illustrate a perpendicular orientation and a tilted orientation respectively of an exemplary stylus according to various examples of the disclosure. 
         FIGS. 8A and 8B  illustrate an azimuth angle and a tilt angle, respectively, for an example stylus and example touch-sensitive device according to examples of the disclosure. 
         FIG. 9A  illustrates an example stylus including a customary ring electrode according to examples of the disclosure. 
         FIG. 9B  illustrates an example stylus including a cylindrical ring electrode according to examples of the disclosure. 
         FIG. 9C  illustrates an example stylus including a cylindrical ring electrode configured to have a more uniform electric field coupling according to examples of the disclosure. 
         FIGS. 10A and 10B  illustrate a perspective view and side view, respectively, of a ring electrode configuration configured to have a more uniform electric field coupling according to examples of the disclosure. 
         FIGS. 11A and 11B  illustrate a perspective view and side view, respectively, of another ring electrode configuration configured to have a more uniform electric field coupling according to examples of the disclosure. 
         FIGS. 12A and 12B  illustrate a perspective view and side view, respectively, of another ring electrode configuration configured to have a more uniform electric field coupling according to examples of the disclosure. 
         FIGS. 12C and 12D  illustrate cross-sectional views of the ring electrode of  FIGS. 12A-12B  at two reference lines along the length of the ring electrode according to examples of the disclosure. 
         FIGS. 13A and 13B  illustrate a cross-sectional view and side view, respectively, of a ring electrode base including routing wires according to examples of the disclosure. 
     
    
    
     DETAILED DESCRIPTION 
     In the following description of examples, reference is made to the accompanying drawings in which it is shown by way of illustration specific examples that can be practiced. It is to be understood that other examples can be used and structural changes can be made without departing from the scope of the various examples. 
     This relates to detection of an orientation, e.g., the azimuth angle and tilt angle, of a stylus relative to a surface. In an example, the orientation of a stylus relative to a contacting surface, e.g., a touch panel, can be detected by detecting a capacitance at one or more locations on the stylus relative to the surface, and then using the capacitance(s) to determine the orientation of the stylus relative to the surface. In some examples, the stylus can include a ring electrode configuration which can improve capacitive coupling between the ring electrode (used for orientation detection) and the touch panel. In some examples, the ring electrode configuration can include a cylindrical ring electrode connected to control circuitry and a ground ring connected to a reference potential, for example, ground. By varying the lengths of ring electrode, ground ring, and the distance between these elements, the electric field emanating from the ring electrode can be tuned to optimize the capacitive coupling between the ring electrode and surface. For example, the coupling between the cylindrical ring electrode and surface can be more uniform along the ring electrode, which can improve tilt accuracy and decrease tilt jitter, resulting in better stylus performance. In some examples, the ring electrode can include multiple sub-rings, with the respective length of each sub-ring increasing with each sub-ring along the length of the electrode away from the stylus tip. In some examples, the ring electrode can comprise a crown shape including projections, each having a width that tapers to a minimum width along the length of the ring electrode. In some cases, the surface area of the ring electrode at a portion (e.g., half of the ring electrode) proximate to the stylus tip can be less than the surface area of the ring electrode at a portion distal to the stylus tip. In some cases, the ring electrode base can include vias and can route writing from the tip electrode, ring electrode, and ground ring through the ring electrode base to control circuitry in the stylus. 
       FIGS. 1A-1D  illustrate examples of systems with touch screens that can accept input from an active stylus according to examples of the disclosure.  FIG. 1A  illustrates an exemplary mobile telephone  136  that includes a touch screen  124  that can accept input from an active stylus according to examples of the disclosure.  FIG. 1B  illustrates an example digital media player  140  that includes a touch screen  126  that can accept input from an active stylus according to examples of the disclosure.  FIG. 1C  illustrates an example personal computer  144  that includes a touch screen  128  that can accept input from an active stylus according to examples of the disclosure.  FIG. 1D  illustrates an example tablet computing device  148  that includes a touch screen  130  that can accept input from an active stylus according to examples of the disclosure. Other devices, including wearable devices, can accept input from an active stylus according to examples of the disclosure. 
     Touch screens  124 ,  126 ,  128  and  130  can be based on, for example, self-capacitance or mutual capacitance sensing technology, or another touch sensing technology. For example, in a self-capacitance based touch system, an individual electrode with a self-capacitance to ground can be used to form a touch pixel (touch node) for detecting touch. As an object approaches the touch pixel, an additional capacitance to ground can be formed between the object and the touch pixel. The additional capacitance to ground can result in a net increase in the self-capacitance seen by the touch pixel. This increase in self-capacitance can be detected and measured by a touch sensing system to determine the positions of multiple objects when they touch the touch screen. 
     A mutual capacitance based touch system can include, for example, drive regions and sense regions, such as drive lines and sense lines. For example, drive lines can be formed in rows while sense lines can be formed in columns (i.e., orthogonal). Touch pixels (touch nodes) can be formed at the intersections or adjacencies (in single layer configurations) of the rows and columns. During operation, the rows can be stimulated with an alternating current (AC) waveform and a mutual capacitance can be formed between the row and the column of the touch pixel. As an object approaches the touch pixel, some of the charge being coupled between the row and column of the touch pixel can instead be coupled onto the object. This reduction in charge coupling across the touch pixel can result in a net decrease in the mutual capacitance between the row and the column and a reduction in the AC waveform being coupled across the touch pixel. This reduction in the charge-coupled AC waveform can be detected and measured by the touch sensing system to determine the positions of multiple objects when they touch the touch screen. In some examples, a touch screen can be multi-touch, single touch, projection scan, full-imaging multi-touch, or any capacitive touch. 
       FIG. 2  illustrates a block diagram of an example computing system  200  that can receive input from an active stylus according to examples of the disclosure. Computing system  200  could be included in, for example, mobile telephone  136 , digital media player  140 , personal computer  144 , tablet computing device  148 , wearable device, or any mobile or non-mobile computing device that includes a touch screen. Computing system  200  can include an integrated touch screen  220  to display images and to detect touch and/or proximity (e.g., hover) events from an object (e.g., finger  203  or active or passive stylus  205 ) at or proximate to the surface of the touch screen  220 . Computing system  200  can also include an application specific integrated circuit (“ASIC”) illustrated as touch ASIC  201  to perform touch and/or stylus sensing operations. Touch ASIC  201  can include one or more touch processors  202 , peripherals  204 , and touch controller  206 . Touch ASIC  201  can be coupled to touch sensing circuitry of touch screen  220  to perform touch and/or stylus sensing operations (described in more detail below). Peripherals  204  can include, but are not limited to, random access memory (RAM) or other types of memory or storage, watchdog timers and the like. Touch controller  206  can include, but is not limited to, one or more sense channels in receive section  208 , panel scan engine  210  (which can include channel scan logic) and transmit section  214  (which can include analog or digital driver logic). In some examples, the transmit section  214  and receive section  208  can be reconfigurable by the panel scan engine  210  based the scan event to be executed (e.g., mutual capacitance row-column scan, mutual capacitance row-row scan, mutual capacitance column-column scan, row self-capacitance scan, column self-capacitance scan, touch spectral analysis scan, stylus spectral analysis scan, stylus scan, etc.). Panel scan engine  210  can access RAM  212 , autonomously read data from the sense channels and provide control for the sense channels. The touch controller  206  can also include a scan plan (e.g., stored in RAM  212 ) which can define a sequence of scan events to be performed at the touch screen. The scan plan can include information necessary for configuring or reconfiguring the transmit section and receive section for the specific scan event to be performed. Results (e.g., touch signals or touch data) from the various scans can also be stored in RAM  212 . In addition, panel scan engine  210  can provide control for transmit section  214  to generate stimulation signals at various frequencies and/or phases that can be selectively applied to drive regions of the touch sensing circuitry of touch screen  220 . Touch controller  206  can also include a spectral analyzer to determine low noise frequencies for touch and stylus scanning. The spectral analyzer can perform spectral analysis on the scan results from an unstimulated touch screen. Although illustrated in  FIG. 2  as a single ASIC, the various components and/or functionality of the touch ASIC  201  can be implemented with multiple circuits, elements, chips, and/or discrete components. 
     Computing system  200  can also include an application specific integrated circuit illustrated as display ASIC  216  to perform display operations. Display ASIC  216  can include hardware to process one or more still images and/or one or more video sequences for display on touch screen  220 . Display ASIC  216  can be configured to generate read memory operations to read the data representing the frame/video sequence from a memory (not shown) through a memory controller (not shown), for example. Display ASIC  216  can be configured to perform various processing on the image data (e.g., still images, video sequences, etc.). In some examples, display ASIC  216  can be configured to scale still images and to dither, scale and/or perform color space conversion on the frames of a video sequence. Display ASIC  216  can be configured to blend the still image frames and the video sequence frames to produce output frames for display. Display ASIC  216  can also be more generally referred to as a display controller, display pipe, display control unit, or display pipeline. The display control unit can be generally any hardware and/or firmware configured to prepare a frame for display from one or more sources (e.g., still images and/or video sequences). More particularly, display ASIC  216  can be configured to retrieve source frames from one or more source buffers stored in memory, composite frames from the source buffers, and display the resulting frames on touch screen  220 . Accordingly, display ASIC  216  can be configured to read one or more source buffers and composite the image data to generate the output frame. 
     Display ASIC  216  can provide various control and data signals to the display, including timing signals (e.g., one or more clock signals) and/or vertical blanking period and horizontal blanking interval controls. The timing signals can include a pixel clock that can indicate transmission of a pixel. The data signals can include color signals (e.g., red, green, blue). The display ASIC  216  can control the touch screen  220  in real-time, providing the data indicating the pixels to be displayed as the touch screen is displaying the image indicated by the frame. The interface to such a touch screen  220  can be, for example, a video graphics array (VGA) interface, a high definition multimedia interface (HDMI), a digital video interface (DVI), a LCD interface, a plasma interface, or any other suitable interface. 
     In some examples, a handoff module  218  can also be included in computing system  200 . Handoff module  218  can be coupled to the touch ASIC  201 , display ASIC  216 , and touch screen  220 , and can be configured to interface the touch ASIC  201  and display ASIC  216  with touch screen  220 . The handoff module  218  can appropriately operate the touch screen  220  according to the scanning/sensing and display instructions from the touch ASIC  201  and the display ASIC  216 . In other examples, the display ASIC  216  can be coupled to display circuitry of touch screen  220  and touch ASIC  201  can be coupled to touch sensing circuitry of touch screen  220  without handoff module  218 . 
     Touch screen  220  can use liquid crystal display (LCD) technology, light emitting polymer display (LPD) technology, organic LED (OLED) technology, or organic electro luminescence (OEL) technology, although other display technologies can be used in other examples. In some examples, the touch sensing circuitry and display circuitry of touch screen  220  can be stacked on top of one another. For example, a touch sensor panel can cover some or all of a surface of the display (e.g., fabricated one on top of the next in a single stack-up or formed from adhering together a touch sensor panel stack-up with a display stack-up). In other examples, the touch sensing circuitry and display circuitry of touch screen  220  can be partially or wholly integrated with one another. The integration can be structural and/or functional. For example, some or all of the touch sensing circuitry can be structurally in between the substrate layers of the display (e.g., between two substrates of a display pixel cell). Portions of the touch sensing circuitry formed outside of the display pixel cell can be referred to as “on-cell” portions or layers, whereas portions of the touch sensing circuitry formed inside of the display pixel cell can be referred to as “in cell” portions or layers. Additionally, some electronic components can be shared, and used at times as touch sensing circuitry and at other times as display circuitry. For example, in some examples, common electrodes can be used for display functions during active display refresh and can be used to perform touch sensing functions during touch sensing periods. A touch screen stack-up sharing components between sensing functions and display functions can be referred to as an in-cell touch screen. 
     Computing system  200  can also include a host processor  228  coupled to the touch ASIC  201 , and can receive outputs from touch ASIC  201  (e.g., from touch processor  202  via a communication bus, such as an serial peripheral interface (SPI) bus, for example) and perform actions based on the outputs. Host processor  228  can also be connected to program storage  232  and display ASIC  216 . Host processor  228  can, for example, communicate with display ASIC  216  to generate an image on touch screen  220 , such as an image of a user interface (UI), and can use touch ASIC  201  (including touch processor  202  and touch controller  206 ) to detect a touch on or near touch screen  220 , such as a touch input to the displayed UI. The touch input can be used by computer programs stored in program storage  232  to perform actions that can include, but are not limited to, moving an object such as a cursor or pointer, scrolling or panning, adjusting control settings, opening a file or document, viewing a menu, making a selection, executing instructions, operating a peripheral device connected to the host device, answering a telephone call, placing a telephone call, terminating a telephone call, changing the volume or audio settings, storing information related to telephone communications such as addresses, frequently dialed numbers, received calls, missed calls, logging onto a computer or a computer network, permitting authorized individuals access to restricted areas of the computer or computer network, loading a user profile associated with a user&#39;s preferred arrangement of the computer desktop, permitting access to web content, launching a particular program, encrypting or decoding a message, and/or the like. Host processor  228  can also perform additional functions that may not be related to touch processing. 
     Computing system  200  can include one or more processors, which can execute software or firmware implementing various functions. Specifically, for integrated touch screens which share components between touch and/or stylus sensing and display functions, the touch ASIC and display ASIC can be synchronized so as to properly share the circuitry of the touch sensor panel. The one or more processors can include one or more of the one or more touch processors  202 , a processor in display ASIC  216 , and/or host processor  228 . In some examples, the display ASIC  216  and host processor  228  can be integrated into a single ASIC, though in other examples, the host processor  228  and display ASIC  216  can be separate circuits coupled together. In some examples, host processor  228  can act as a master circuit and can generate synchronization signals that can be used by one or more of the display ASIC  216 , touch ASIC  201  and handoff module  218  to properly perform sensing and display functions for an in-cell touch screen. The synchronization signals can be communicated directly from the host processor  228  to one or more of the display ASIC  216 , touch ASIC  201  and handoff module  218 . Alternatively, the synchronization signals can be communicated indirectly (e.g., touch ASIC  201  or handoff module  218  can receive the synchronization signals via the display ASIC  216 ). 
     Computing system  200  can also include a wireless module (not shown). The wireless module can implement a wireless communication standard such as a WiFi®, BLUETOOTH™ or the like. The wireless module can be coupled to the touch ASIC  201  and/or host processor  228 . The touch ASIC  201  and/or host processor  228  can, for example, transmit scan plan information, timing information, and/or frequency information to the wireless module to enable the wireless module to transmit the information to an active stylus, for example (i.e., a stylus capable generating and injecting a stimulation signal into a touch sensor panel). For example, the computing system  200  can transmit frequency information indicative of one or more low noise frequencies the stylus can use to generate a stimulation signals. Additionally or alternatively, timing information can be used to synchronize the stylus  205  with the computing system  200 , and the scan plan information can be used to indicate to the stylus  205  when the computing system  200  performs a stylus scan and expects stylus stimulation signals (e.g., to save power by generating a stimulus only during a stylus scan period). In some examples, the wireless module can also receive information from peripheral devices, such as an active stylus  205 , which can be transmitted to the touch ASIC  201  and/or host processor  228 . In other examples, the wireless communication functionality can be incorporated in other components of computing system  200 , rather than in a dedicated chip. 
     Note that one or more of the functions described herein can be performed by firmware stored in memory and executed by the touch processor in touch ASIC  201 , or stored in program storage and executed by host processor  228 . The firmware can also be stored and/or transported within any non-transitory computer-readable storage medium for use by or in connection with an instruction execution system, apparatus, or device, such as a computer-based system, processor-containing system, or other system that can fetch the instructions from the instruction execution system, apparatus, or device and execute the instructions. In the context of this document, a “non-transitory computer-readable storage medium” can be any medium (excluding a signal) that can contain or store the program for use by or in connection with the instruction execution system, apparatus, or device. The non-transitory computer readable medium storage can include, but is not limited to, an electronic, magnetic, optical, electromagnetic, infrared, or semiconductor system, apparatus or device, a portable computer diskette (magnetic), a random access memory (RAM) (magnetic), a read-only memory (ROM) (magnetic), an erasable programmable read-only memory (EPROM) (magnetic), a portable optical disc such a CD, CD-R, CD-RW, DVD, DVD-R, or DVD-RW, or flash memory such as compact flash cards, secured digital cards, USB memory devices, memory sticks, and the like. 
     The firmware can also be propagated within any transport medium for use by or in connection with an instruction execution system, apparatus, or device, such as a computer-based system, processor-containing system, or other system that can fetch the instructions from the instruction execution system, apparatus, or device and execute the instructions. In the context of this document, a “transport medium” can be any medium that can communicate, propagate or transport the program for use by or in connection with the instruction execution system, apparatus, or device. The transport readable medium can include, but is not limited to, an electronic, magnetic, optical, electromagnetic or infrared wired or wireless propagation medium. 
     It is to be understood that the computing system  200  is not limited to the components and configuration of  FIG. 2 , but can include other or additional components in multiple configurations according to various examples. Additionally, the components of computing system  200  can be included within a single device, or can be distributed between multiple devices. 
     As discussed above, the touch screen  220  can include touch sensing circuitry.  FIG. 3  illustrates an example touch screen including touch sensing circuitry configured as drive and sense regions or lines according to examples of the disclosure. Touch screen  320  can include touch sensing circuitry that can include a capacitive sensing medium having a plurality of drive lines  322  and a plurality of sense lines  323 . It should be noted that the term “lines” is sometimes used herein to mean simply conductive pathways, as one skilled in the art will readily understand, and is not limited to elements that are strictly linear, but includes pathways that change direction, and includes pathways of different size, shape, materials, etc. Additionally, the drive lines  322  and sense lines  323  can be formed from smaller electrodes coupled together to form drive lines and sense lines. Drive lines  322  can be driven by stimulation signals from the transmit section  214  through a drive interface  324 , and resulting sense signals generated in sense lines  323  can be transmitted through a sense interface  325  to sense channels in receive section  208  (also referred to as an event detection and demodulation circuit) in touch controller  206 . In this way, drive lines and sense lines can be part of the touch sensing circuitry that can interact to form capacitive sensing nodes, which can be thought of as touch picture elements (touch pixels), such as touch pixels  326  and  327 . This way of understanding can be particularly useful when touch screen  320  is viewed as capturing an “image” of touch. In other words, after touch controller  206  has determined whether a touch has been detected at each touch pixel in the touch screen, the pattern of touch pixels in the touch screen at which a touch occurred can be thought of as an “image” of touch (e.g., a pattern of fingers or other objects touching the touch screen). 
     It should be understood that the row/drive and column/sense associations can be exemplary, and in other examples, columns can be drive lines and rows can be sense lines. In some examples, row and column electrodes can be perpendicular such that touch nodes can have x and y coordinates, though other coordinate systems can also be used, and the coordinates of the touch nodes can be defined differently. It should be understood that touch screen  220  can include any number of row electrodes and column electrodes to form the desired number and pattern of touch nodes. The electrodes of the touch sensor panel can be configured to perform various scans including some or all of row-column and/or column-row mutual capacitance scans, self-capacitance row and/or column scans, row-row mutual capacitance scans, column-column mutual capacitance scans, and stylus scans. 
     Additionally or alternatively, the touch screen can include touch/hover sensing circuitry including an array of pixelated electrodes.  FIG. 4  illustrates an example touch screen including touch sensing circuitry configured as pixelated electrodes according to examples of the disclosure. Touch screen  420  can include touch sensing circuitry that can include a capacitive sensing medium having a plurality of electrically isolated touch pixel electrodes  422  (e.g., a pixelated touch screen). For example, in a self-capacitance configuration, touch pixel electrodes  422  can be coupled to sense channels in receive section  208  in touch controller  206 , can be driven by stimulation signals from the sense channels (or transmit section  214 ) through drive/sense interface  425 , and can be sensed by the sense channels through the drive/sense interface as well, as described above. Labeling the conductive plates used to detect touch (i.e., touch pixel electrodes  422 ) as “touch pixel” electrodes can be particularly useful when touch screen  420  is viewed as capturing an “image” of touch. In other words, after touch controller  206  has determined an amount of touch detected at each touch pixel electrode  422  in touch screen  420 , the pattern of touch pixel electrodes in the touch screen at which a touch occurred can be thought of as an “image” of touch (e.g., a pattern of fingers or other objects touching the touch screen). The pixelated touch screen can be used to sense mutual capacitance and/or self-capacitance. 
     As discussed herein, in addition to performing touch scans to detect an object such as a finger or a passive stylus, computing system  200  can also perform stylus scans to detect an active stylus and communicate with a stylus. For example, an active stylus can be used as an input device on the surface of a touch screen of touch-sensitive device.  FIG. 5A  illustrates a side view of an exemplary stylus according to various examples. In the example of  FIG. 5A , stylus  500  can include shaft  518  and tip  512 . The tip  512  can include electrode  501  at the distal end of the tip for contacting a surface and ring electrode  503  proximate to the distal end and forming a ring around the tip. The electrodes  501 ,  503  can be any suitable conductive material, such as metal, paint, ink, and the like. In some examples, the tip can be replaceable. The shaft  518  can similarly be any suitable conductive material or any suitable insulating material, depending on the requirements of the stylus  500 . The shaft  518  can house stylus control circuitry  504 , e.g., signal transmitting and receiving elements, signal processing elements, and the like, depending on the requirements of the stylus  500 . 
     Stylus  500  can also include control circuitry  504 . Control circuitry  504  can be configured to generate one or more stylus stimulation signals at the one or more electrodes  501 ,  503  to stimulate a touch-sensitive device. For example, stylus stimulation signals can be coupled from stylus  500  to the touch sensing circuitry of touch screen  220 , and the received signals can be processed by the touch ASIC  201 . The received signals can be used to determine a location of active stylus  500  at the surface of touch screen  220 . In some examples control circuitry  504  can include one or more processors. In some examples, one or more of the stylus functions described herein can be performed by firmware stored in memory or in program storage (not shown) and executed a processor in control circuitry  504 . 
       FIG. 5B  illustrates a bottom view of the exemplary stylus of  FIG. 5A  according to various examples. In the example of  FIG. 5B , stylus  500  can have a conical shaped tip  512  with electrode  501  at the distal end of the tip and ring electrode  503  proximate to the distal end and forming a ring around the tip. 
       FIG. 6  illustrates an example touch sensor panel configuration operable with the touch ASIC of  FIG. 2  to perform a stylus scan according to examples of the disclosure. During a stylus scan, one or more stimulation signals can be injected by stylus  604  proximate to one or more touch nodes  606 . The stimulation signals injected by stylus  604  can create capacitive coupling Cxr between the stylus  604  and one or more row traces  601  and capacitive coupling Cxc between the stylus  604  and one or more column traces  602  corresponding to the one or more proximate touch nodes  606 . The capacitive coupling Cxr and Cxc between the stylus  604  and the one or more touch nodes  606  can vary based on the proximity of stylus  604  to the one or more touch nodes  606 . During the stylus scan, the transmit section  214  can be disabled, i.e., no stimulation signals Vstim from the touch controller are sent to touch sensor panel  600 . The capacitive coupling (e.g., mutual capacitance) can be received by the receive section  208  from the row and column traces of the one or more touch nodes  606  for processing. As described herein, in some examples the one or more stylus stimulation signals can have one or more frequencies. The one or more frequencies can be selected by the touch ASIC  201  using information from a stylus spectral analysis scan (described below in more detail). This frequency information can be wirelessly communicated to the stylus  604  so that the stylus  604  can generate stimulation signals at the appropriate frequencies. 
     In some examples, one or more multiplexers can be used to couple row and/or column electrodes to the receive section and/or transmit section. For example, during a mutual capacitance touch sensing scan, row traces can be coupled to the transmit section and column traces can be coupled to the receive section. During a stylus sensing scan, column traces (or row traces) can be coupled via the one or more multiplexers to the receive section to detect input from a stylus or other input device along one axis of the touch screen, and then the row traces (or column traces) can be coupled via the one or more multiplexers to the receive section to detect input from a stylus or other input device along a second axis of the touch screen. In some examples, the row and column traces can be sensed simultaneously. In some examples, the stylus can be detected on the column traces concurrently with the mutual capacitance scan touch sensing scan. The touch and stylus signals can be differentiated by filtering and demodulating the received response signals at different frequencies. 
     A stylus can have various orientations (e.g., azimuth angle and tilt angle) as it touches or hovers over a touch panel. In some examples, an electronic device can perform an action based on stylus orientation. Accordingly, detecting the stylus orientation can be helpful in device operation. 
       FIGS. 7A and 7B  illustrate various orientations of the exemplary stylus of  FIGS. 5A and 5B  as it touches a touch panel according to various examples. In the example of  FIG. 7A , stylus  700  can have a perpendicular orientation as it touches touch panel  720 . As the stylus  700  touches the panel  720 , tip electrode  701  can form capacitance C 1  with a proximate conductive element, e.g., row(s) and/or column(s), (not shown) of the panel. Similarly, ring electrode  703  can form capacitance C 2  with a proximate conductive element, e.g., row(s) and/or column(s), of the panel  720 . Image  730  captured at the panel  720  shows example touch or hover images resulting from the two capacitances C 1 , C 2 . Because the stylus  700  is perpendicular to the panel  720 , the image  730  can show the tip capacitance C 1  image surrounded by the ring capacitance C 2  image. 
     In the example of  FIG. 7B , the stylus  700  can have a tilted orientation as it touches the panel  720 . As a result, the image  730  captured at the panel  720  can show a shift in the positions of the touch or hover images resulting from two capacitances C 1 , C 2  relative to each other. Here, the ring capacitance C 2  image has shifted to the right of the tip capacitance C 1  image. The amount of the shift can be a function of the amount of stylus tilt. For example, the greater the tilt, the further the ring capacitance C 2  image is from the tip capacitance C 1  image. Conversely, the lesser the tilt, the more the ring capacitance C 2  image overlaps and becomes centered over the tip capacitance C 1  image. Therefore, by determining the proximity of the two capacitances C 1 , C 2  images in the captured image, the amount of stylus tilt can be determined. 
     The image can also be used to determine the direction of the stylus tilt, e.g., upward, downward, right, left, and so on, relative to the touch panel  720 . For example, in the image  730  of  FIG. 7B , the ring capacitance C 2  image is to the right of the tip capacitance C 1  image. This can indicate that the stylus  700  is tilted to the right. If the ring capacitance C 2  image is at the left of the tip capacitance C 1  image, this can indicate that the stylus  700  is tilted to the left. If the ring capacitance C 2  image is above the tip capacitance C 1  image, this can indicate that the stylus  700  is tilted upward. If the ring capacitance C 2  image is below the tip capacitance C 1  image, this can indicate that the stylus  700  is tilted downward. Other tilt directions, e.g., upper left, lower right, etc., can also be determined according to the relative positions of the capacitance C 1 , C 2  images. 
     By determining the proximity of the two capacitances C 1 , C 2  to each other and their relative positions in an image, the stylus orientation can be detected. It should be understood that although the capacitance C 1  image and capacitance C 2  image are illustrated here as circular, the capacitance image can be of other shapes, including linear shapes. 
       FIGS. 8A and 8B  illustrate an azimuth angle and a tilt angle, respectively, for an example stylus and example touch-sensitive device according to examples of the disclosure.  FIG. 8A  illustrates an example stylus  802  contacting an example touch sensor panel  800  at point  801 . Line  804  illustrated in  FIG. 8A  can represent a reference vector in the plane of touch sensor panel  800  and passing through point  801 . Line  806  can represent a projection vector projecting the stylus onto the plane of the touch sensor panel  800 . The angle  808  formed between the projection vector (line  806 ) and reference vector (line  804 ) can be referred to as the azimuth angle.  FIG. 8B  illustrates the example stylus  802  contacting the example touch sensor panel  800  at point  810 . Line  812  illustrated in  FIG. 8B  can represent a perpendicular reference vector perpendicular to the plane of touch sensor panel  800  and passing through point  810 . The angle  814  formed between the reference vector (line  812 ) and stylus  802  can be referred to as the tilt angle. 
     Tilt accuracy and tilt jitter can be useful metrics to evaluate the performance of a tilt sensor in a stylus. Tilt accuracy represents the difference between the detected tilt angle and the actual tilt angle of the stylus. Tilt jitter represents the stability of the detected tilt angle. For example, when a stylus is held at a certain tilt angle, the detected tilt angle should be stationary. However, in the presence of noise, the detected tilt angle may vary (jitter) over time, even though the stylus is stationary. Because styli can be used at varying angles (e.g., typically between 20° and 70°), orientation or tilt-dependent performance can limit the effectiveness of the stylus as an input device. In some cases, the tilt accuracy and tilt jitter of a stylus can depend, at least in part, on the geometry of the tilt sensor and its corresponding electric field (e.g., the electric field of the ring electrode). Accordingly, it can be beneficial to utilize a tilt sensor with geometry that improves the tilt accuracy and tilt jitter performance of a stylus. 
       FIG. 9A  illustrates a stylus  900  including a tip electrode  901  and a customary ring electrode  903   a , where the stylus is in contact with a surface  920  of a touch sensitive device. As shown, the customary ring electrode  903   a  can be positioned distal to the tip electrode and can have a relatively short length. For example, the length of ring electrode  903   a  can be less than the cross-sectional diameter of the ring electrode. The electric field  931  coupling (e.g., capacitive coupling) of ring electrode  903   a  is also symbolically illustrated as arrows extending from the ring electrode, where dense clustering of arrows represents a stronger electric field coupling. As shown, the coupling of electric field  931  to the surface  920  can be limited to a small region below the ring electrode. In some cases (e.g., when stylus  900  is held at a high angle), the coupling between the customary ring electrode  903   a  and surface  920  can be weak due to the distance between the electrode and surface, which can result in decreased tilt angle accuracy and increased tilt jitter for the stylus. 
       FIG. 9B  illustrates a stylus including a tip electrode  901  and a cylindrical ring electrode  903   b , where the stylus is in contact with a surface  920  of a touch sensitive device. Unlike the customary ring electrode  903   a  shown in  FIG. 9A , the ring electrode  903   b  can have a longer length; for example, the length of the ring electrode can be 3 mm-7 mm, which can be greater than the cross-sectional diameter of the ring electrode. The electric field coupling  932  of ring electrode  903   b  is symbolically illustrated as arrows extending from the ring electrode, where dense clustering of arrows represents a stronger electric field coupling (e.g., capacitive coupling). As shown, coupling generally occurs between points along an electrode (e.g., between points  943  and  944  shown) and points along a corresponding line projecting the electrode onto the surface  920  (e.g., the plane of the touch sensor panel as shown in  FIG. 8B ). Because of the longer length of the cylindrical ring electrode, more electric field can couple (i.e., capacitively couple) between the cylindrical ring electrode and surface  920 . However, as shown in  FIG. 9B , in some cases (e.g., when stylus is held at an angle), the electric field coupling  932  can be uneven, that is, the coupling can be much stronger where the ring electrode  903   b  is nearest the surface  920  (e.g., coupling originating at point  943 ), and can decrease sharply as the distance between the electrode and surface increases (e.g., coupling originating at point  944 ). In other words, the coupling can decrease sharply along the length of the electrode in a direction away from the stylus tip. In some cases, this can result in less tilt angle accuracy and increased tilt jitter. 
     As illustrated in the examples set forth above, it can be beneficial for a stylus to utilize a ring electrode wherein the electric field coupling (i.e., capacitive coupling) with a touch sensitive surface is more uniform along the length of the ring electrode when the stylus is held at an angle.  FIG. 9C  illustrates an example ring electrode  903   c  configured to have a more uniform electric field coupling when a stylus is held at an angle. Specific examples of ring electrodes will be discussed in more detail below with reference to  FIGS. 10-13 . The electric field coupling  933  of ring electrode  903   c  is symbolically illustrated as arrows extending from the ring electrode, where dense clustering of arrows represent a stronger electric field coupling. As in the example shown in  FIG. 9B , coupling generally occurs between points along the electrode and points along a corresponding line projecting the electrode onto the surface  920 . However, unlike the example of  FIG. 9B , the coupling can be more uniform along the length of the electrode  903   c  as the stylus  900  is held at an angle. In some examples, this more uniform coupling can coincide with an electric field of the electrode which is stronger at points distal to the stylus tip (e.g., point  941 ) than at points nearer to the stylus tip (e.g., point  942 ). In other words, ring electrode  903   c  can produce an electric field which increases in strength along the length of the electrode such that the electric field coupling (i.e., capacitive coupling) with surface  920  is more uniform when a stylus is held at an angle. Accordingly, as shown in the example of  FIG. 9C , when stylus  900  is held at an angle, the electric field coupling originating from point  941  can be similar (at a larger distance from surface  920 ) to the electric field coupling originating from point  942  (at a smaller distance from the surface). 
       FIGS. 10-12  below discuss examples of ring electrodes characterized by a more uniform capacitive coupling (e.g., resulting from an electric field which is stronger at points distal to the stylus tip). In some of the examples shown in  FIGS. 10-12 , ring electrode can correspond, for example, to ring electrode  503  shown in the example of  FIG. 5A . For clarity, additional elements which can be present in a stylus (e.g., tip electrode, shaft, etc.) are omitted in  FIGS. 10-12 . In each of the examples shown, the ring electrode can be any suitable conductive material, such as metal, conductive paint, conductive ink, and the like. In some configurations, the ring electrode can be cylindrical in shape and partially or fully encompass a ring electrode base, wherein the ring electrode base is formed, at least in part, of a non-conductive material. In the examples shown here, the electrode base is cylindrical in shape, though the scope of this disclosure is not so limited. The configuration of the electrode base, including the routing of the electrical components in the ring electrode configuration, will be discussed in more detail below with reference to  FIGS. 13A-13B . 
       FIGS. 10A-10B  illustrate an exemplary ring electrode configuration  1010  according to examples of the disclosure.  FIG. 10A  illustrates a perspective view of an exemplary ring electrode configuration including a single cylindrical ring electrode  1015 . In the example shown, ring electrode base  1050  (e.g., the non-conductive support for conductive elements) can be cylindrical in shape and can be formed of any suitable non-conductive material. Ring electrode configuration  1010  can include a ground ring  1013  formed of any suitable conductive material. In some examples, the ring electrode configuration can include a proximate end piece  1012  proximate to the stylus tip. The proximate end piece  1012  can include a connector  1031  which can connect to the stylus tip electrode (not shown). In some configurations, a distal end piece can be formed of a conductive material, and in some cases, the distal end piece can be electrically grounded and operate as a ground plate  1017 . 
       FIG. 10B  illustrates a side view of the ring electrode configuration  1010 . As shown, ring electrode configuration  1010  can have a total length L 1 . The proximate end piece  1012  can have a length L 2 . Ground ring  1013  can have a length L 3 . Ring electrode  1015  can be separated on one side from ground ring  1013  by a portion of non-conductive material portion  1014  (shown in shaded area) having a distance L 4 , and can be separated on an opposite side by another portion of non-conductive material  1016  (shown in shaded area) having a distance L 6 . Ring electrode  1015  can have a length of L 5  and a diameter of D 1 . Ground plate  1017  can have a length L 7 . Ring electrode  1015  can be separated from the distal end of the ring electrode configuration  1010  by a length L 9  (i.e., the combined length of L 6  and L 7 ) and separated from proximate end of the ring electrode configuration  1010  by a length L 8  (i.e., the combined length of L 2 , L 3 , and L 4 ). As set forth above with reference to  FIG. 5A , ring electrode  1015  can electrically couple to control circuitry  504  or other stylus circuitry for transmitting and receiving signals. In configurations like that shown in  FIGS. 10A-10B , the shape of the electric field emanating from ring electrode  1015  can be influenced by ground ring  1013  and ground plate  1017 . Specifically, some of the electric field emanating from the ring electrode  1015  near the ground ring can be coupled to ground ring  1013 . Similarly, some of the electric field emanating from ring electrode  1015  near the ground plate  1017  can be coupled to ground plate  1017 . Consequently, the shape of the electric field emanating from ring electrode  1015  can be tuned by varying the lengths L 1 , L 3 , L 4 , L 5  and L 6 . 
     In some examples, as the length L 3  of ground ring  1013  increases or as the separation L 4  between ground ring  1013  and ring electrode  1015  decreases, the electric field strength emanating from the end of ring electrode  1015  proximate to the stylus tip is reduced. Similarly, the electric field strength emanating from the end of ring electrode distal to the stylus tip can be reduced as the length L 7  of ground plate  1017  is increased or as the separation L 6  between ring electrode  1015  and ground plate  1017  is decreased. In some examples, the variables L 1 , L 3 , L 4 , L 5  and L 6  can be selected such that the electric field emanating from the end of ring electrode  1015  proximate to a stylus tip is weaker than the electric field emanating from the end of ring electrode  1015  distal to the stylus tip. Consequently, when a stylus having ring electrode configuration  1010  is held at an angle above a touch sensitive surface, the electric field coupling to the surface can be more uniform, as discussed above with reference to  FIG. 9C . This can result in improved tilt accuracy and decreased tilt jitter. In some example configurations like that shown in  FIG. 10B , to achieve a desired electric field shape, the length L 5  of the ring electrode  1015  can be in a range of 3 mm and 7 mm. In some examples, the length L 4  separating ground ring  1013  from ring electrode  1015  can be in a range of 3.5 mm and 6 mm. In some examples, the distance L 6  between ring electrode  1015  and ground plate  1017  can be in a range of 2 mm and 4 mm. In some examples, the diameter D 1  of ring electrode  1015  can be in a range of 1 mm and 3 mm. More generally, in some examples, the length L 5  can be less than L 4 , and the length L 6  can be less than the length L 5 . 
       FIGS. 11A-11B  illustrate another exemplary ring electrode configuration  1110  according to examples of the disclosure.  FIG. 11A  illustrates a perspective view of an exemplary ring electrode configuration in which ring electrode  1115  comprises a plurality of electrically connected sub-rings  1119 ,  1121 ,  1123 , each having a cylindrical shape. As in the previous example of  FIGS. 10A-10B , ring electrode configuration  1110  can also include a ground ring  1113  formed of any suitable conductive material. In this example, the ring electrode configuration can include a proximate end piece  1112  and ground plate  1117 , which can be similar to the proximate end piece  1012  and ground plate  1017  described with reference to  FIGS. 10A-10B  above. In some examples, adjacent sub-rings  1119 ,  1121 ,  1123  can be electrically connected via connecting traces  1140 ,  1142  of conductive material (e.g., the same material forming ring electrode  1115 ) formed outside of the electrode base  1150 . In the example shown here, connecting traces  1140 ,  1142  can be formed at different positions along the circumference of electrode base  1150 . For example, a first trace  1140  connecting sub-rings  1119  and  1121  can be formed at a different angle orthogonal to the radial axis of the ring electrode than second trace  1142 . In other examples, the second trace  1142  can be formed at the same angle. In some configurations not shown, more than one connecting trace can connect two adjacent sub-rings. In other examples not shown, the sub-rings may be electrically connected to one another using wiring routed, for example, through the electrode base  1150 . 
       FIG. 11B  illustrates a side view of the ring electrode configuration  1110 . As shown, ring electrode configuration  1110  can have a total length L 1 . The proximate end piece  1112  can have a length L 2 . Ground ring  1113  can have a length L 3 . Ring electrode  1115  can be separated on one side from ground ring  1113  by a portion of non-conductive material  1114  (shown shaded) having a distance L 4 , and can be separated on an opposite side by another portion of non-conductive material  1116  (shown shaded) having a distance L 6 . Ring electrode  1115  can have a length of L 5  and a diameter of D 1 . Ground plate  1117  can have a length L 7 . Ring electrode  1115  can be separated from the distal end of the ring electrode configuration  1110  by a length L 9  (i.e., the combined length of L 6  and L 7 ) and separated from proximate end of the ring electrode configuration  1110  by a length L 8  (i.e., the combined length of L 2 , L 3 , and L 4 ). Ring electrode  1115  can be comprised of three sub-rings  1119 ,  1121 ,  1123 . A first sub-ring  1119  can have a length L 9  and can be separated from a second sub-ring  1121  by a portion of non-conductive material  1120  having a length L 10 . The second sub-ring  1121  can have a length L 11  and can be separated from a third sub-ring  1123  by a another portion of non-conductive material  1122  having a length L 12 . The third sub-ring  1123  can have a length of L 13 . Each of the connecting traces  1140 ,  1142  can have the same width W 1 , though in other cases the width may vary between connecting traces. 
     Like the example explained with reference to  FIGS. 10A-10B  above, the shape of the electric field emanating from ring electrode  1115  can be influenced by ground ring  1113  and ground plate  1117 . Specifically, some of the electric field emanating from the ring electrode  1115  near the ground ring can be coupled to ground ring  1113 . Similarly, some of the electric field emanating from ring electrode  1115  near the ground plate  1117  can be coupled to ground plate  1117 . Also like the example of  FIGS. 10A-10B , the shape of the electric field emanating from ring electrode  1115  can be tuned, at least in part, by varying the lengths L 1 , L 3 , L 4 , L 5  and L 6 . In addition, the shape of the electric field emanating from ring electrode  1115  can be tuned, in part, by the lengths L 9 , L 11 , and L 13  of sub-rings  1119 ,  1121 , and  1123 , respectively, and the lengths L 10  and L 12  separating the sub-rings. It should be noted that although this example discloses a ring electrode comprising three sub-rings, ring electrodes can include any multitude of sub-rings in order to achieve a desired tilt accuracy and tilt jitter performance. Further, one skilled in the art would recognize that the lengths and separation lengths of the additional sub-rings can be likewise tuned to achieve a desired result. 
     As in the example discussed with reference to  FIGS. 10A-10B  above, as the length L 3  of ground ring  1113  increases or as the separation L 4  between ground ring  1113  and ring electrode  1115  decreases, the electric field strength emanating from the end of ring electrode  1115  proximate to the stylus tip is reduced. Similarly, the electric field strength emanating from the end of ring electrode distal to the stylus tip can be reduced as the length L 7  of ground plate  1117  is increased or as the separation L 6  between ring electrode  1115  and ground plate  1117  is decreased. In addition, dimensions can be selected such that when the sub-ring lengths on the end proximate to the stylus tip (e.g., L 9 , L 11 ) are larger than the sub-ring lengths on the end distal to the stylus tip (e.g., L 13 ), the electric field strength can further be shaped to be stronger on the end distal to the stylus tip. 
     In some examples, the electric field shape of ring electrode  1115  can be approximated based on the surface area of portions of the ring electrode. Specifically, ring electrode  1115  can be conceptually divided in a cross-sectional plane orthogonal to the radial axis at a length L 5 /2 to form two conceptual portions. When the surface area of ring electrode  1115  (i.e., the total surface area of the conductive material forming the ring electrode) at the first portion proximate to stylus tip is less than the surface area of ring electrode  1115  at the second portion distal to the stylus tip, the electric field corresponding to the first portion can be weaker than the electric field corresponding to the second portion. That is, the electric field can be weaker proximate to the stylus tip and stronger distal to the stylus tip. Accordingly, in some examples, the total surface area of a first half of ring electrode  1115  that is proximate to the stylus tip can be less than the total surface than a second half of ring electrode that is distal to the stylus tip. One skilled in the art would understand that the conceptual division of ring electrode  1115  need not be an equal division (e.g., a division at L 5 /2). Moreover, ring electrode  1115  can be conceptually divided into greater portions (e.g., three portions each of a length L 5 /3), and the surface area of each portion can be progressively greater along the length of the ring electrode in a direction away from the stylus tip. 
     Some example dimensions for the ring electrode configuration  1110  shown in  FIGS. 11A-11B  will now be discussed. In some examples, sub-rings  1119 ,  1121 ,  1123  can increase in length along the length of ring electrode  1115 . For example, length L 11  of sub-ring  1121  can be greater than length L 9  of sub-ring  1119 , and length L 13  of sub-ring  1123  can be greater than length L 11  of sub-ring  1121 . In some configurations, the length of a non-conductive separation adjacent to a sub-ring and distal from the stylus tip can be the same as the length of the sub-ring. For example, the length L 10  of non-conductive separation  1120  adjacent to sub-ring  1119  and distal to the stylus tip can be the same as the length L 9  of sub-ring  1119 . Similarly, the length L 12  of non-conductive separation  1122  adjacent to sub-ring  1121  and distal to the stylus tip can be the same as the length L 11  of sub-ring  1121 . In some configurations, each progressive sub-ring along the length of a ring electrode can increase in length by a scaling factor. For example, if a ring electrode includes N sub-rings, the length of the sub-rings can be defined as shown in Equation (1) below:
 
 L   SN   =L   B ( s   N−1 )  (1)
 
where L SN  is the length of an N th  sub-ring S N , L B  is the baseline length (i.e., the length of the smallest subring), and s is the scaling factor. In some examples, the scaling factor s can be 2. In this case, to find the length of a third sub-ring (i.e., where N=3), Equation (1) can reduce as shown in Equation (2) below:
 
 L   S3   =L   B (2 3−1 )=4 L   B   (2)
 
where L B  is the baseline length (i.e., the length of the smallest sub-ring). In some examples, ring electrode  1115  can have a baseline length in a range of 0.25 mm to 1 mm, the number of sub-rings can be 3, and the scaling factor s can be in a range of 1.5 and 2.5.
 
     It should be noted that, as in the examples discussed above with reference to  FIGS. 10A-10B , ground ring  1113  and ground plate  1117  can influence the shape of the electric field emanated from ring electrode  1115 . As such, sub-rings  1119 ,  1121 ,  1123  need not necessarily be of increasing length in order to achieve a desired shape of the electric field. Similarly, in some examples, the lengths of sub-rings  1119 ,  1121 ,  1123  need not follow the formula set forth in Equation (1) in order to yield desired results. In some cases, the dimensions of ground ring  1113 , ground plate  1117 , and the separations between these elements and ring electrode  1115  can be similar to those discussed above with reference to  FIGS. 10A-10B . Specifically, in some example configurations like that shown in  FIG. 11B , to achieve a desired electric field shape, the length L 5  of the ring electrode  1115  can be in a range of 3 mm and 7 mm. In some examples, the length L 4  separating ground ring  1113  from ring electrode  1115  can be in a range of 3.5 mm and 6 mm. In some examples, the distance L 6  between ring electrode  1115  and ground plate  1117  can be in a range of 2 mm and 4 mm. In some examples, the diameter D 1  of ring electrode  1115  can be in a range of 1 mm and 3 mm. Moreover, in some examples, sub-ring  1119  length L 9  can be in a range of 0.25 mm and 1 mm. The non-conductive separation  1120  length L 10  between sub-ring  1119  and sub-ring  1121  can be in a range of 0.25 mm and 1 mm. Sub-ring  1121  length L 11  can be in a range of 0.5 mm and 2 mm. The non-conductive separation  1122  length L 12  between sub-ring  1121  and sub-ring  1123  can be in a range of 0.5 mm and 2 mm. Sub-ring  1123  length L 13  can be in a range of 1 mm and 3 mm. 
       FIGS. 12A-12D  illustrate another exemplary ring electrode configuration  1210  according to examples of the disclosure.  FIG. 12A  illustrates a perspective view of an exemplary ring electrode configuration in which ring electrode  1215  can comprise a cylindrical crown-shaped electrode having a plurality of projections  1240  that decrease in width along the length of the ring electrode toward the stylus tip. As in the previous example of  FIGS. 10A-10B , ring electrode configuration  1210  can also include a ground ring  1213  formed of any suitable conductive material. In this example, the ring electrode configuration can include a proximate end piece and ground plate  1217 , which can be similar to the proximate end piece  1212  and ground plate  1217  described with reference to  FIGS. 10A-10B  above. 
       FIG. 12B  illustrates a side view of the ring electrode configuration  1210 . As shown, ring electrode configuration  1210  can have a total length L 1 . The proximate end piece  1212  can have a length L 2 . Ground ring  1213  can have a length L 3 . Ring electrode  1215  can be separated on one side from ground ring  1213  by a portion of non-conductive material  1242  (shown shaded) having a distance L 4 , and can be separated on an opposite side by another portion of non-conductive material  1216  (shown shaded) having a distance L 6 . Ring electrode  1215  can have a length of L 5  and a diameter of D 1 . Ground plate  1217  can have a length L 7 . Ring electrode  1215  can be separated from the distal end of the ring electrode configuration  1210  by a length L 9  (i.e., the combined length of L 6  and L 7 ) and separated from proximate end of the ring electrode configuration  1210  by a length L 8  (i.e., the combined length of L 2 , L 3 , and L 4 ). 
     Ring electrode  1215  can comprise a cylindrical crown shape wherein projections  1240  each can have a uniform length L 9  and a width that tapers to a minimum width along the length of the ring electrode. Each of the projections  1240  can originate from a solid cylindrical portion  1241  having a length L 10  and extend along the length of the ring electrode. In some examples, each of the projections  1240  can have a width that tapers (i.e., decreases linearly) to a minimum width along the length of the ring electrode  1215  in the direction of the stylus tip (e.g., the direction of connector  1231 ). For example, at a reference line B shown in  FIG. 12B , a projection can have a width W 2 , while at a reference line A, nearer to the stylus tip than reference line B, the projection can have a width W 1 , smaller than W 2 . 
     As similarly explained with reference to  FIGS. 10A-10B  above, the shape of the electric field emanating from ring electrode  1215  can be influenced by ground ring  1213  and ground plate  1217 . Specifically, some of the electric field emanating from the ring electrode  1215  near the ground ring can be coupled to ground ring  1213 . Similarly, some of the electric field emanating from ring electrode  1215  near the ground plate  1217  can be coupled to ground plate  1217 . Also as in the example of  FIGS. 10A-10B , the shape of the electric field emanating from ring electrode  1215  can be tuned, at least in part, by varying the lengths L 1 , L 3 , L 4 , L 5  and L 6 . In addition, the shape of the electric field emanating from ring electrode  1215  can be tuned, in part, by the length L 10  of solid cylindrical portion  1241 , the number of projections  1240  extending from the solid cylindrical portion, and the shape of the projections, including the projection lengths L 9 . For example, where the length of solid cylindrical portion  1241  is larger, the electric field can be stronger at the end of the ring electrode  1215  distal to the stylus tip. In addition, as the width of projections  1240  tapers to a minimum width, the electric field emanating from the ring electrode  1215  at these points can also decrease. Thus, these variables can be tuned in order to achieve a desired electric field coupling (i.e., capacitive coupling) between the ring electrode and a touch-sensitive surface, which can lead to better tilt accuracy and less tilt jitter. 
       FIGS. 12C-12D  illustrate a cross-sectional view of ring electrode  1215  at two positions along the length of the ring electrode corresponding to reference lines A and B respectively in  FIG. 12B . As shown, projections  1240  can be equidistantly spaced around the circumference of the ring electrode base  1250  (not shown) about a center point  1243  and can conform to the cylindrical shape of the ring electrode base. In the example shown here, ring electrode  1215  can include eight projections  1240 . As indicated in both  FIGS. 12B and 12C , at the reference line A nearer to the stylus tip, the projections can each have a width W 3 . As shown in both  FIGS. 12B and 12D , at the reference line B distal to the stylus tip, the projections can each have a width W 4 , greater than W 3 . In general, the width of a projection in the configuration shown in  FIGS. 12A-12D  can be defined according to Equation (3) below: 
                     W   d     =         (       L   ⁢           ⁢   5     -   d     )     ⁢     (   c   )           (   N   )     ⁢     (     L   9     )                 (   3   )               
where d represents a distance from the ring electrode end distal to the stylus tip, L 5  represents the length of the ring electrode as shown in  FIG. 12B , W d  represents the width of a projection at a distance d, c represents the circumference of the circle formed by a cross-section of the cylinder at the distance d, N represents the number of projections in the ring electrode, and L 9  represents the length of the projections as indicated in  FIG. 12B . In some configurations, the strength of the electric field emanating from an area of ring electrode  1215  can correspond to the width of the projections  1240  at that area.
 
     As similarly discussed with reference to  FIGS. 11A-11B  above, the electric field shape of ring electrode  1215  can be approximated based on the surface area of portions of the ring electrode. Here, if ring electrode  1215  is conceptually divided in a cross-sectional plane perpendicular to the radial axis of the ring electrode at a length L 5 /2 to form two conceptual portions, the surface area of ring electrode  1215  at the first portion proximate to stylus tip (e.g., the portion having the more tapered end of projections  1240 ) is less than the surface area of ring electrode  1215  at the second portion distal to the stylus tip (e.g., the portion having the solid cylindrical portion  1241  and the wider ends of the projections). Therefore, the electric field can be weaker proximate to the stylus tip and stronger distal to the stylus tip. One skilled in the art would understand that the conceptual division of ring electrode  1215  need not be an equal division (e.g., a division at L 5 /2). Moreover, ring electrode  1215  can be conceptually divided into greater portions (e.g., three portions each of a length L 5 /3), and the surface area of each portion can be progressively greater along the length of the ring electrode in a direction away from the stylus tip. 
     Some example dimensions for the ring electrode configuration  1210  shown in  FIGS. 12A-12D  will now be discussed. As in previous examples, the length L 5  of the ring electrode can be in a range of 3 mm to 7 mm. In some examples, the length L 9  of projections  1240  can be greater than the length L 10  of the solid cylindrical portion  1241 . In some examples, a ratio of the length L 9  of projections  1240  to the length L 10  of solid cylindrical portion  1241  can be in a range of 2:1 and 3:1. In some examples like those shown in  FIGS. 12A-12D , the length L 9  of projections  1240  can be in a range of 2.5 mm and 4.5 mm, and the length L 10  of the solid cylindrical portion  1241  can be in a range of 0.5 mm and 2.5 mm. 
     It should be noted that, as in the examples discussed above with reference to  FIGS. 10A-10B , ground ring  1213  and ground plate  1217  can influence the shape of the electric field emanated from ring electrode  1215 . In some cases, the dimensions of ground ring  1213 , ground plate  1217 , and the separations between these elements and ring electrode  1215  can be similar to those discussed above with reference to  FIGS. 10A-10B . Specifically, in some example configurations like that shown in  FIGS. 12A-12D , to achieve a desired electric field shape, the length L 5  of the ring electrode  1215  can be in a range of 3 mm and 7 mm. In some examples, the length L 4  separating ground ring  1213  from ring electrode  1215  can be in a range of 3.5 mm and 6 mm. In some examples, the distance L 6  between ring electrode  1215  and ground plate  1217  can be in a range of 2 mm and 4 mm. In some examples, the diameter D 1  of ring electrode  1215  can be in a range of 1 mm and 3 mm. It should be understood that the ring electrodes including projections illustrated in  FIGS. 12A-12D  are exemplary only. The scope of this disclosure contemplates additional configurations in which the projections are of a different shape, including projections having a width that tapers non-linearly. 
     Although the example configurations discussed herein with reference to  FIGS. 10-12  have been discussed as separate configurations, in some examples, different configurations may be combined such that the ring electrode electric field coupling with the touch sensitive surface results in improved stylus performance (e.g., increased tilt accuracy and decreased tilt jitter). For example, the sub-rings of the configurations discussed with reference to  FIGS. 11A-11B  can be combined with the tapered projections discussed with reference to  FIGS. 12A-12D . 
       FIG. 13A  illustrates an exemplary cross-sectional view of a ring electrode base  1350  including a simplified circuit diagram of routing wires  1343 - 1345  according to examples of the disclosure. The ring electrode base  1350  can correspond, for example, to the ring electrode base  1050  discussed with reference to  FIGS. 10A-10B  above. For reference, the locations of tip electrode  1301 , ground ring  1313 , ring electrode  1315 , and non-conductive portions  1314  and  1316  are illustrated in dashed lines. In some examples, ring electrode base  1350  can include a first connector  1331  configured to electrically couple to a tip electrode  1301  (illustrated in dashed line) as discussed above with reference to  FIGS. 5A-5B . Signals from tip electrode  1301  can be routed through the ring electrode base via one or more tip electrode routing wires  1343 . Additionally, ring electrode base  1350  can include a second connector  1332  distal to the stylus tip and configured to electrically couple to control circuitry  504  (not shown) as discussed above with reference to  FIG. 5A . In some examples, ground ring  1313  can include a ground via  1341  coupled to one or more ground routing wires  1344 . Similarly, ring electrode  1315  can include an electrode via  1342  coupled to one or more ring electrode routing wires  1345 . Though not shown here, ring electrode base  1350  can include additional vias, for example, vias corresponding to ground via  1341  and electrode via  1342  on a side opposite vias  1341  and  1342 . Tip electrode routing wires  1343 , ground routing wires  1344 , and ring electrode routing wires  1345  can be routed through the ring electrode base  1350  to the second connector  1332 . From the second connector, the signals on the routing wires can be routed to the control circuitry  504 . 
       FIG. 13B  illustrates a top view of the ring electrode base  1350 . In some configurations ground via  1341  and electrode via  1342  can be necessary to couple the ground ring  1313  and ring electrode  1315  to routing wires  1344  and  1345 , respectively. Due to manufacturing constraints, vias  1341  and  1342  may need to be of a minimum diameter D 2  in order to be properly coupled to routing wires. Additionally, vias  1341  and  1342  may need to be separated from adjacent components by at least length L 14  to satisfy manufacturing constraints. As discussed with reference to at least  FIGS. 10A-10B  above, length L 3  of ground ring  1313  can be tuned in order to achieve a desired electric field coupling (i.e., capacitive coupling) between ring electrode  1315  and a touch sensitive surface. In some examples, the length L 3  of ground ring  1313  may be less than the combined length of the minimum separation length L 14  and via diameter D 2 . Accordingly, as shown in  FIG. 13B , a portion of ground via  1341  can extend outside of ground ring  1313  in the area of the non-conductive separation  1314 . In some examples, half of ground via  1341  associated with ground ring  1313  can be positioned on the ground ring  1313  and half of the via can protrude into the non-conductive separation area  1314 . 
     It should be noted that although often described in the context of a stylus, the examples herein can be applied to other input devices interacting with touch-sensitive surfaces. Additionally, although often described with regard to a touch screen, the input devices can be used with touch-sensitive devices that do not include a touch screen. Finally, it should be noted that elements of the examples described herein can be combined in different ways, including adding or omitting various elements illustrated or described herein. 
     Some examples of the disclosure are directed to an apparatus comprising: a base formed of a non-conductive material; a ring electrode formed of a conductive material and encircling the base; a ground ring formed of the conductive material and encircling the base and separated from the ring electrode by a first distance; and a ground plate formed of a second conductive material and separated from the ring electrode by a second distance; wherein the ring electrode is connected to a drive circuitry, the ground ring is connected to a reference potential, and the ground plate is connected to the reference potential. Additionally or alternatively to one or more of the examples disclosed above, in some examples, at least a portion of the ring electrode is a hollow cylindrical shape having a first outer diameter, and wherein at least a portion of the ground electrode is a hollow cylindrical shape having the first outer diameter. Additionally or alternatively to one or more of the examples disclosed above, in some examples, the ring electrode has a length greater than the first outer diameter of the ring electrode. 
     Additionally or alternatively to one or more of the examples disclosed above, in some examples, the ring electrode has a first length and the ground ring has a second length less than the first length; Additionally or alternatively to one or more of the examples disclosed above, in some examples, the first distance between the ring electrode and ground ring is smaller than the first length of the ground ring. Additionally or alternatively to one or more of the examples disclosed above, in some examples, the first length is in a range of 3 mm and 7 mm. Additionally or alternatively to one or more of the examples disclosed above, in some examples, the first distance is in a range of 3.5 mm and 6 mm. Additionally or alternatively to one or more of the examples disclosed above, in some examples, the second distance is in a range of 2 mm and 4 mm. Additionally or alternatively to one or more of the examples disclosed above, in some examples, the apparatus further comprises a first connector configured to couple the apparatus to a tip electrode of a stylus device. Additionally or alternatively to one or more of the examples disclosed above, in some examples, the ring electrode is configured to capacitively couple to a touch-sensitive surface, and the ring electrode is also configured to capacitively couple to the ground ring. Additionally or alternatively to one or more of the examples disclosed above, in some examples, the apparatus further comprises one or more first conductive traces coupled to the ring electrode, one or more second conductive traces coupled to the ground ring, wherein the first and second conductive traces are routed through the base. Additionally or alternatively to one or more of the examples disclosed above, in some examples, the apparatus further comprises one or more first vias configured to couple the first conductive traces to the ring electrode and one or more second vias configured to couple the second conductive traces to the ground ring. Additionally or alternatively to one or more of the examples disclosed above, in some examples, at least one of the one or more second vias has a circular shape with a second diameter which is larger than a length of the ground ring. Additionally or alternatively to one or more of the examples disclosed above, in some examples, the reference potential is a ground voltage. 
     Some examples of the disclosure are directed to an electrode for an active stylus, comprising: a plurality of hollow cylindrical sub-rings positioned parallel to one another along a length of the electrode; wherein each of the sub-rings is separated from adjacent sub-rings in a first direction by a respective separation distance; and wherein a respective length of each sub-ring increases with each of the hollow cylindrical sub-ring along the length of the electrode in the first direction. Additionally or alternatively to one or more of the examples disclosed above, in some examples, the respective length of each sub-ring along the length of the electrode increases by a scaling factor. Additionally or alternatively to one or more of the examples disclosed above, in some examples, the scaling factor is in a range of 1.5 and 2.5. Additionally or alternatively to one or more of the examples disclosed above, in some examples, a separation distance between a first sub-ring and a second sub-ring adjacent in a first direction is equal to a length of the first sub-ring. Additionally or alternatively to one or more of the examples disclosed above, in some examples, each of the sub-rings are electrically connected via one or more conductive traces. 
     Additionally or alternatively to one or more of the examples disclosed above, in some examples, each of the conductive traces in the electrode are formed on a same cylindrical contour and are situated at different angles with respect to a radial axis of the cylindrical contour. Additionally or alternatively to one or more of the examples disclosed above, in some examples, if the electrode is conceptually divided into a first and second half of equal axial length by a plane orthogonal to a radial axis of the electrode, the first half has a surface area greater than a surface area of the second half. 
     Some examples of the disclosure are directed to an electrode for an active stylus, comprising: a hollow cylindrical ring portion; a plurality of projections forming a crown shape; wherein each of the plurality of projections originates at the hollow cylindrical ring portion and extends from the hollow cylindrical ring portion along a length of the electrode toward a first end, and wherein each of the plurality of projections has a maximum width at the hollow cylindrical ring portion which tapers to a minimum width at the first end of the electrode. Additionally or alternatively to one or more of the examples disclosed above, in some examples, each of the plurality of projections has a first length; and the hollow cylindrical ring portion has a second length less than the first length. Additionally or alternatively to one or more of the examples disclosed above, in some examples, a ratio of the first length to the second length is in a range of 2:1 and 3:1. Additionally or alternatively to one or more of the examples disclosed above, in some examples, the first length is in a range of 2.5 mm and 4.5 mm, and the second length is in a range of 0.5 mm and 2.5 mm. 
     Some examples of the disclosure are directed to an input device comprising: a body including a shaft portion and a tip portion; a tip electrode at the distal end of the input device and disposed in the tip portion; a ring electrode apparatus disposed in the tip portion distal to the tip electrode, wherein the ring electrode apparatus includes: a base formed of a non-conductive material; a ring electrode formed of a conductive material and encircling the base; a ground ring formed of the conductive material and encircling the base and separated from the ring electrode by a first distance; a ground plate formed of a second conductive material and separated from the ring electrode by a second distance; stimulation circuitry coupled to the ring electrode and configured to generate one or more stimulation signals. 
     Although examples have been fully described with reference to the accompanying drawings, it is to be noted that various changes and modifications will become apparent to those skilled in the art. Such changes and modifications are to be understood as being included within the scope of the various examples as defined by the appended claims.

Metadata:
Filing Date: 20150908
Publication Date: 20180717
Grant Date: 20180717
Priority Date: 20150908
Inventors: BHANDARI, PRIYANKA
MARSHALL, BLAKE R.
TAN, LI-QUAN
NASIRI MAHALATI, REZA
ZIMMERMAN, AIDAN N.
BROOKS, Ryan P.
ARMENDARIZ, KEVIN C.
Assignee: APPLE INC
CPC Classifications: [{"code": "G06F3/03545", "inventive": true, "first": false, "tree": "[]"}, {"code": "G06F3/03545", "inventive": true, "first": true, "tree": "[]"}, {"code": "H01G5/145", "inventive": true, "first": false, "tree": "[]"}, {"code": "H01G5/12", "inventive": true, "first": false, "tree": "[]"}, {"code": "H01G5/145", "inventive": true, "first": false, "tree": "[]"}, {"code": "G06F3/0383", "inventive": true, "first": false, "tree": "[]"}, {"code": "H01G5/12", "inventive": true, "first": false, "tree": "[]"}, {"code": "G06F3/03545", "inventive": true, "first": false, "tree": "[]"}, {"code": "H01G5/12", "inventive": true, "first": false, "tree": "[]"}, {"code": "H01G5/145", "inventive": true, "first": false, "tree": "[]"}, {"code": "H01G5/12", "inventive": true, "first": false, "tree": "[]"}, {"code": "G06F3/03545", "inventive": true, "first": false, "tree": "[]"}, {"code": "G06F3/0383", "inventive": true, "first": true, "tree": "[]"}, {"code": "H01G5/145", "inventive": true, "first": false, "tree": "[]"}, {"code": "G06F3/044", "inventive": true, "first": false, "tree": "[]"}, {"code": "G06F3/0442", "inventive": true, "first": false, "tree": "[]"}, {"code": "G06F3/0446", "inventive": true, "first": true, "tree": "[]"}, {"code": "G06F3/0443", "inventive": true, "first": false, "tree": "[]"}, {"code": "G06F3/0442", "inventive": true, "first": false, "tree": "[]"}, {"code": "G06F3/0383", "inventive": true, "first": false, "tree": "[]"}, {"code": "G06F3/0442", "inventive": true, "first": false, "tree": "[]"}, {"code": "G06F3/0446", "inventive": true, "first": true, "tree": "[]"}, {"code": "G06F3/0443", "inventive": true, "first": false, "tree": "[]"}]
Family ID: 56940364