Patent Publication Number: US-11029769-B2

Title: Pen for use with a touch screen

Description:
STATEMENT REGARDING FEDERALLY SPONSORED RESEARCH OR DEVELOPMENT 
     Not Applicable. 
     INCORPORATION-BY-REFERENCE OF MATERIAL SUBMITTED ON A COMPACT DISC 
     Not Applicable. 
     BACKGROUND OF THE INVENTION 
     Technical Field of the Invention 
     This invention relates to computer systems and more particularly to interaction with a touch screen of a computing device. 
     Description of Related Art 
     Computers include user interfaces to receive data from a user and to output data to a user. A common user interface is a graphical user interface (GUI) that provides images, or icons, for various types of data input (e.g., select a file, edit a word, type a character, draw a picture, look at a photo, format a document, etc.). In an example, the user selects an icon by manipulating a mouse to align a cursor with an icon and then “selects” the icon. In another example, the user selects an icon by touching the screen with the user&#39;s finger or with a special pen. 
     For general use of a pen with computers from different manufacturers and/or having different touch screen technologies, a pen includes a ring-back topology as described in patent application PCT/US201267897. The ring-back topology includes an inverting charge integrator and an inverting amplifier. When the tip of a ring-back pen touches the screen, the tip receives a signal from the screen. The inverting charge integrator integrates and inverts the received signal. The inverting amplifier inverts the integrated and inverted signal to produce an output signal that resembles the received signal. The pen sends the output signal back to the screen. The output signal affects the signal transmitted by the screen, which screen interprets as a touch. 
    
    
     
       BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWING(S) 
         FIG. 1  is a schematic block diagram of an embodiment of a communication device with a pen and/or an input device in accordance with the present invention; 
         FIG. 2  is a schematic block diagram of an embodiment of a computing device in accordance with the present invention; 
         FIG. 3  is a schematic block diagram of another embodiment of a computing device in accordance with the present invention; 
         FIG. 4  is a schematic block diagram of an embodiment of a touch screen electrode pattern in accordance with the present invention; 
         FIG. 5  is a schematic block diagram of an example of capacitance of a touch screen with no touch in accordance with the present invention; 
         FIG. 6  is a schematic block diagram of an example of capacitance of a touch screen with a touch from a pen or a device in accordance with the present invention; 
         FIG. 6A  is a schematic block diagram of an embodiment of an operational amplifier configuration in accordance with the present invention; 
         FIG. 7  is a schematic block diagram of an embodiment of a pen in accordance with the present invention; 
         FIG. 8  is a schematic block diagram of another embodiment of a pen in accordance with the present invention; 
         FIG. 9  is a schematic block diagram of an embodiment of a sense-regulation circuit and a response circuit of a pen in accordance with the present invention; 
         FIG. 10  is a schematic block diagram of an example of ring-back with no data in accordance with the present invention; 
         FIG. 11  is a schematic block diagram of an example of ring-back with data in accordance with the present invention; 
         FIG. 12  is a schematic block diagram of another embodiment of a sense-regulation circuit and a response circuit of a pen in accordance with the present invention; 
         FIG. 13  is a schematic block diagram of another embodiment of a pen in accordance with the present invention; 
         FIG. 14  is a schematic block diagram of another embodiment of a pen in accordance with the present invention; 
         FIG. 15  is a schematic block diagram of another embodiment of a sense-regulation circuit of a pen in accordance with the present invention; 
         FIG. 16  is a schematic block diagram of another embodiment of a sense-regulation circuit of a pen in accordance with the present invention; 
         FIG. 17  is a schematic block diagram of an embodiment of a data source circuit and a processing circuit of a pen in accordance with the present invention; 
         FIG. 18  is a schematic block diagram of an embodiment of a data sense circuit of a pen in accordance with the present invention; 
         FIG. 19A  is a schematic block diagram of an embodiment of a device in accordance with the present invention; 
         FIG. 19B  is a schematic block diagram of another embodiment of a device in accordance with the present invention; 
         FIG. 20  is a schematic block diagram of an embodiment of a sense-regulation circuit of a device in accordance with the present invention; 
         FIG. 21  is a schematic block diagram of another embodiment of a sense-regulation circuit of a device in accordance with the present invention; 
         FIG. 22  is a schematic block diagram of an embodiment of a touch screen to touch screen communication between two computing devices in accordance with the present invention; 
         FIG. 23A  is a schematic block diagram of an example of a frequency pattern representing data in accordance with the present invention; 
         FIGS. 23B-23F  are schematic block diagrams of examples of electrode patterns representing data in accordance with the present invention; 
         FIG. 24  is a schematic block diagram of an example of a device including a housing and AC coupling circuit in accordance with the present invention; and 
         FIG. 25  is a schematic block diagram of an embodiment of a device in accordance with the present invention. 
     
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
       FIG. 1  is a schematic block diagram of an embodiment of a computing device  10  having a touch screen  12 , which may further include a display to form a touch screen display. The computing device  10 , which will be discussed in greater detail with reference to one or more of  FIGS. 2-3 , may be a portable computing device and/or a fixed computing device. A portable computing device may be a social networking device, a gaming device, a cell phone, a smart phone, a digital assistant, a digital music player, a digital video player, a laptop computer, a handheld computer, a tablet, a video game controller, and/or any other portable device that includes a computing core. 
     A fixed computing device may be a computer (PC), an interactive white board, an interactive table top, an interactive desktop, an interactive display, a computer server, a cable set-top box, vending machine, an Automated Teller Machine (ATM), an automobile, a satellite receiver, a television set, a printer, a fax machine, home entertainment equipment, a video game console, and/or any type of home or office computing equipment. An interactive display functions to provide users with an interactive experience (e.g., touch the screen to obtain information, be entertained, etc.). For example, a store provides interactive displays for customers to find certain products, to obtain coupons, to enter contests, etc. 
     A pen  16  and/or a device  14  interacts with the touch screen  12  to communication data with the computing device  10 . For example, the pen  16  touches, or nearly touches, the touch screen at a pen interaction area  20 . Within the pen interaction area  20 , the touch screen  12  transmits a signal, or multiple signals, which are received by the pen  16 . In a ring back mode, the pen  16  mimics the signal it receives and sends it back to the touch screen  12 . In a more advanced mode, the pen  16  includes data with the ring back signal to provide additional information to the touch screen. For example, the data includes pen orientation data (e.g., angles of the pen in two or more axis), pressure data (e.g., how hard the user is pressing the pen on the screen), pen functionality (e.g., fine tip, coarse tip, clean line, fuzzy line, etc.), pen mode (e.g., draw, write, erase), pen features (e.g., color, button presses, etc.), pen data (e.g., battery life, user information, feature set, capabilities, etc.), etc. 
     In another advanced mode, the touch screen  12  provides additional data to the pen  16 . For example, the signal, or signals, transmitted by the touch screen include embedded data. The embedded data for the pen  16  includes a variety of information. For example, the embedded data for the pen includes feedback for fine tuning the interaction between the pen and the touch screen (e.g., frequency selection, power control, etc.). In another example, the embedded data for the pen includes authentication data to ensure that user of the pen on the computing device is authorized to do so. 
     The device  14  interacts with the touch screen  12  in a similar manner as the pen  16 , but may include more touch points to provided additional information. For example, the device  14  is a mouse, a ruler, a game piece, an educational piece for communicating data with an interactive desktop, an interactive tabletop, and/or an interactive white board. As another example, the device  14  is a cell phone case for facilitating communication between a cell phone and an interactive desktop, an interactive tabletop, and/or an interactive white board. As yet another example, the device  14  is circuitry included in cell phones to enable touch screen to touch screen communication. 
       FIG. 2  is a schematic block diagram of an embodiment of a computing device  10  that includes a core control module  40 , one or more processing modules  42 , one or more main memories  44 , cache memory  46 , a video graphics processing module  48 , a display  50 , an Input-Output (I/O) peripheral control module  52 , one or more input interface modules, one or more output interface modules, one or more network interface modules  60 , and one or more memory interface modules  62 . A processing module  42  is described in greater detail at the end of the detailed description of the invention section and, in an alternative embodiment, has a direction connection to the main memory  44 . In an alternate embodiment, the core control module  40  and the I/O and/or peripheral control module  52  are one module, such as a chipset, a quick path interconnect (QPI), and/or an ultra-path interconnect (UPI). 
     Each of the main memories  44  includes one or more Random Access Memory (RAM) integrated circuits, or chips. For example, a main memory  44  includes four DDR4 (4 th  generation of double data rate) RAM chips, each running at a rate of 2,400 MHz. In general, the main memory  44  stores data and operational instructions most relevant for the processing module  42 . For example, the core control module  40  coordinates the transfer of data and/or operational instructions from the main memory  44  and the memory  64 - 66 . The data and/or operational instructions retrieve from memory  64 - 66  are the data and/or operational instructions requested by the processing module or will most likely be needed by the processing module. When the processing module is done with the data and/or operational instructions in main memory, the core control module  40  coordinates sending updated data to the memory  64 - 66  for storage. 
     The memory  64 - 66  includes one or more hard drives, one or more solid state memory chips, and/or one or more other large capacity storage devices that, in comparison to cache memory and main memory devices, is/are relatively inexpensive with respect to cost per amount of data stored. The memory  64 - 66  is coupled to the core control module  40  via the I/O and/or peripheral control module  52  and via one or more memory interface modules  62 . In an embodiment, the I/O and/or peripheral control module  52  includes one or more Peripheral Component Interface (PCI) buses to which peripheral components connect to the core control module  40 . A memory interface module  62  includes a software driver and a hardware connector for coupling a memory device to the I/O and/or peripheral control module  52 . For example, a memory interface  62  is in accordance with a Serial Advanced Technology Attachment (SATA) port. 
     The core control module  40  coordinates data communications between the processing module(s)  42  and a network, or networks, via the I/O and/or peripheral control module  52 , the network interface module(s)  60 , and a network card  68  or  70 . A network card  68  or  70  includes a wireless communication unit or a wired communication unit. A wireless communication unit includes a wireless local area network (WLAN) communication device, a cellular communication device, a Bluetooth device, and/or a ZigBee communication device. A wired communication unit includes a Gigabit LAN connection, a Firewire connection, and/or a proprietary computer wired connection. A network interface module  60  includes a software driver and a hardware connector for coupling the network card to the I/O and/or peripheral control module  52 . For example, the network interface module  60  is in accordance with one or more versions of IEEE 802.11, cellular telephone protocols, 10/100/1000 Gigabit LAN protocols, etc. 
     The core control module  40  coordinates data communications between the processing module(s)  42  and input device(s) via the input interface module(s) and the I/O and/or peripheral control module  52 . An input device includes a keypad, a keyboard, control switches, a touchpad, a microphone, a camera, etc. An input interface module includes a software driver and a hardware connector for coupling an input device to the I/O and/or peripheral control module  52 . In an embodiment, an input interface module is in accordance with one or more Universal Serial Bus (USB) protocols. 
     The core control module  40  coordinates data communications between the processing module(s)  42  and output device(s) via the output interface module(s) and the I/O and/or peripheral control module  52 . An output device includes a speaker, etc. An output interface module includes a software driver and a hardware connector for coupling an output device to the I/O and/or peripheral control module  52 . In an embodiment, an output interface module is in accordance with one or more audio codec protocols. 
     The processing module  42  communicates directly with a video graphics processing module  48  to display data on the display  50 . The display  50  includes an LED (light emitting diode) display, an LCD (liquid crystal display), and/or other type of display technology. The display has a resolution, an aspect ratio, and other features that affect the quality of the display. The video graphics processing module  48  receives data from the processing module  42 , processes the data to produce rendered data in accordance with the characteristics of the display, and provides the rendered data to the display  50 . 
     The display  50  includes the touch screen  12 , a plurality of drive-sense circuits (DSC), and a touch screen processing module  82 . The touch screen  12  includes a plurality of sensors (e.g., electrodes, capacitor sensing cells, capacitor sensors, inductive sensor, etc.) to detect a proximal touch of the screen. For example, when a pen touches the screen, capacitance of sensors proximal to the touch(es) are affected (e.g., impedance changes). As another example, when a pen touches the screen, a sensor&#39;s signal is changed (e.g., magnitude increase, magnitude decrease, phase shift, etc.). The drive-sense circuits (DSC) coupled to the affected sensors detect the change and provide a representation of the change to the touch screen processing module  82 , which may be a separate processing module or integrated into the processing module  42 . 
     The touch screen processing module  82  processes the representative signals from the drive-sense circuits (DSC) to determine the location of the touch(es). This information is inputted to the processing module  42  for processing as an input. For example, a touch represents a selection of a button on screen, a scroll function, a zoom in-out function, etc. 
       FIG. 3  is a schematic block diagram of another embodiment of a computing device  10  that includes the touch screen  12 , the drive-sense circuits (DSC), the touch screen processing module  81 , a display  83 , electrodes  85 , the processing module  42 , the video graphics processing module  48 , and a display interface. The display  83  may be a large screen display (e.g., for portable computing devices) or a large screen display (e.g., for fixed computing devices). In general, a large screen display has a resolution equal to or greater than full high definition (HD), an aspect ratio of a set of aspect ratios, and a screen size equal to or greater than thirty-two inches. The following table lists various combinations of resolution, aspect ratio, and screen size for the display  83 , but it&#39;s not an exhaustive list. 
     
       
         
           
               
               
               
               
               
               
             
               
                   
               
               
                   
                 Width 
                 Height 
                 pixel 
                 screen 
                   
               
               
                 Resolution 
                 (lines) 
                 (lines) 
                 aspect ratio 
                 aspect ratio 
                 screen size (inches) 
               
               
                   
               
             
            
               
                   
               
            
           
           
               
               
               
               
               
               
            
               
                 HD (high 
                 1280 
                 720 
                 1:1 
                 16:9 
                 32, 40, 43, 50, 55, 60, 65, 
               
               
                 definition) 
                   
                   
                   
                   
                 70, 75, &amp;/or &gt;80 
               
               
                 Full HD 
                 1920 
                 1080 
                 1:1 
                 16:9 
                 32, 40, 43, 50, 55, 60, 65, 
               
               
                   
                   
                   
                   
                   
                 70, 75, &amp;/or &gt;80 
               
               
                 HD 
                 960 
                 720 
                 4:3 
                 16:9 
                 32, 40, 43, 50, 55, 60, 65, 
               
               
                   
                   
                   
                   
                   
                 70, 75, &amp;/or &gt;80 
               
               
                 HD 
                 1440 
                 1080 
                 4:3 
                 16:9 
                 32, 40, 43, 50, 55, 60, 65, 
               
               
                   
                   
                   
                   
                   
                 70, 75, &amp;/or &gt;80 
               
               
                 HD 
                 1280 
                 1080 
                 3:2 
                 16:9 
                 32, 40, 43, 50, 55, 60, 65, 
               
               
                   
                   
                   
                   
                   
                 70, 75, &amp;/or &gt;80 
               
               
                 QHD (quad 
                 2560 
                 1440 
                 1:1 
                 16:9 
                 32, 40, 43, 50, 55, 60, 65, 
               
               
                 HD) 
                   
                   
                   
                   
                 70, 75, &amp;/or &gt;80 
               
               
                 UHD (Ultra 
                 3840 
                 2160 
                 1:1 
                 16:9 
                 32, 40, 43, 50, 55, 60, 65, 
               
               
                 HD) or 4K 
                   
                   
                   
                   
                 70, 75, &amp;/or &gt;80 
               
               
                 8K 
                 7680 
                 4320 
                 1:1 
                 16:9 
                 32, 40, 43, 50, 55, 60, 65, 
               
               
                   
                   
                   
                   
                   
                 70, 75, &amp;/or &gt;80 
               
               
                 HD and 
                 1280-&gt;=7680 
                 720-&gt;=4320 
                 1:1, 2:3, etc. 
                  2:3 
                 50, 55, 60, 65, 70, 75, 
               
               
                 above 
                   
                   
                   
                   
                 &amp;/or &gt;80 
               
               
                   
               
            
           
         
       
     
     The display  83  is one of a variety of types of displays that is operable to render frames of data into visible images. For example, the display is one or more of: a light emitting diode (LED) display, an electroluminescent display (ELD), a plasma display panel (PDP), a liquid crystal display (LCD), an LCD high performance addressing (HPA) display, an LCD thin film transistor (TFT) display, an organic light emitting diode (OLED) display, a digital light processing (DLP) display, a surface conductive electron emitter (SED) display, a field emission display (FED), a laser TV display, a carbon nanotubes display, a quantum dot display, an interferometric modulator display (IMOD), and a digital microshutter display (DMS). The display is active in a full display mode or a multiplexed display mode (i.e., only part of the display is active at a time). 
     The touch screen  12  includes integrated electrodes  85  that provide the sensors for the touch sense part of the touch screen display. The electrodes  85  are distributed throughout the display area or where touch screen functionality is desired. For example, a first group of the electrodes are arranged in rows and a second group of electrodes are arranged in columns. 
     The electrodes  85  are comprised of a transparent conductive material and are in-cell or on-cell with respect to layers of the display. For example, a conductive trace is placed in-cell or on-cell of a layer of the touch screen display. The transparent conductive material, which is substantially transparent and has negligible effect on video quality of the display with respect to the human eye. For instance, an electrode is constructed from one or more of: Indium Tin Oxide, Graphene, Carbon Nanotubes, Thin Metal Films, Silver Nanowires Hybrid Materials, Aluminum-doped Zinc Oxide (AZO), Amorphous Indium-Zinc Oxide, Gallium-doped Zinc Oxide (GZO), and poly polystyrene sulfonate (PEDOT). 
     In an example of operation, the processing module  42  is executing an operating system application  89  and one or more user applications  91 . The user applications  91  includes, but is not limited to, a video playback application, a spreadsheet application, a word processing application, a computer aided drawing application, a photo display application, an image processing application, a database application, etc. While executing an application  91 , the processing module generates data for display (e.g., video data, image data, text data, etc.). The processing module  42  sends the data to the video graphics processing module  48 , which converts the data into frames of video  87 . 
     The video graphics processing module  48  sends the frames of video  87  (e.g., frames of a video file, refresh rate for a word processing document, a series of images, etc.) to the display interface  93 . The display interface  93  provides the frames of video to the display  83 , which renders the frames of video into visible images. 
     While the display  83  is rendering the frames of video into visible images, the drive-sense circuits (DSC) provide sensor signals to the electrodes  85 . When the screen is touched by a pen or device, signals on the electrodes  85  proximal to the touch (i.e., directly or close by) are changed. The DSCs detect the change for effected electrodes and provide the detected change to the touch screen processing module  81 . 
     The touch screen processing module  81  processes the change of the effected electrodes to determine one or more specific locations of touch and provides this information to the processing module  42 . Processing module  42  processes the one or more specific locations of touch to determine if an operation of the application is to be altered. For example, the touch is indicative of a pause command, a fast forward command, a reverse command, an increase volume command, a decrease volume command, a stop command, a select command, a delete command, etc. 
     If the signals received from the pen or device include embedded data, the touch screen processing module  81  interprets the embedded data and provides the resulting information to the processing module  42 . If, computing device  10  is not equipped to process embedded data, the pen or device still communicated with the computing device using the change to the signals on the effected electrodes (e.g., increase magnitude, decrease magnitude, phase shift, etc.). 
       FIG. 4  is a schematic block diagram of an embodiment of a touch screen electrode pattern that includes rows of electrodes  85 - r  and columns of electrodes  85 - c . Each row of electrodes  85 - r  and each column of electrodes  85 - c  includes a plurality of individual conductive cells (e.g., white squares for rows, gray squares for columns) that are electrically coupled together. The size of a cell depends on the desired resolution of touch sensing. For example, a cell size is 5 millimeters by 5 millimeters, which provides adequate touch sensing for cell phones and tablets. Making the cells smaller improves touch resolution and will typically reduce touch sensor errors (e.g., touching a “w” by an “e” is displayed). While the cells are shown to be square, they may be of any polygonal shape or circular shape. 
     The cells for the rows and columns may be on the same layer, as shown, or on different layers. The electrically coupling between the cells is done using vias and running traces on another layer. Note that the cells are on one or more ITO layers of a touch screen, which includes a touch screen display. 
       FIG. 5  is a cross section schematic block diagram of an example of capacitance of a touch screen  12  with no touch of a pen or a device. The electrode  85   s  are positioned proximal to dielectric layer  73 , which is between cover dielectric layer  71  and the display substrate  75 . Each electrode  85  has a self-capacitance, which corresponds to a parasitic capacitance created by the electrode with respect to other conductors in the display (e.g., ground, conductive layer(s), and/or one or more other electrodes). For example, row electrode  85 - r  has a parasitic capacitance C p2  and column electrode  85 - c  has a parasitic capacitance C p1 . Note that each electrode includes a resistance component and, as such, produces a distributed R-C circuit. The longer the electrode, the greater the impedance of the distributed R-C circuit. For simplicity of illustration the distributed R-C circuit of an electrode will be represented as a single parasitic capacitance. 
     As shown, the touch screen  12  includes a plurality of layers  71 - 75 . Each illustrated layer may itself include one or more layers. For example, dielectric layer  71  includes a surface protective film, a glass protective film, and/or one or more pressure sensitive adhesive (PSA) layers. As another example, the second dielectric layer  73  includes a glass cover, a polyester (PET) film, a support plate (glass or plastic) to support, or embed, one or more of the electrodes  85 - c  and  85 - r , a base plate (glass, plastic, or PET), an ITO layer, and one or more PSA layers. As yet another example, the display substrate  75  includes one or more LCD layers, a back-light layer, one or more reflector layers, one or more polarizing layers, and/or one or more PSA layers. 
     A mutual capacitance (Cm_0) exists between a row electrode and a column electrode. When no touch is present, the self-capacitances and mutual capacitances of the touch screen  12  are at a nominal state. Depending on the length, width, and thickness of the electrodes, separation from the electrodes and other conductive surfaces, and dielectric properties of the layers, the self-capacitances and mutual capacitances can range from a few pico-Farads to 10&#39;s of nano-Farads. 
       FIG. 6  is a schematic block diagram of an example of capacitance of a touch screen with a touch from a pen  16  or a device  14 . The pen  16  or device  14  is capacitive coupled to the row and column electrodes proximal to the touch. When the pen  16  or device  14  is touch by a person and is touching the touch screen, the person provides a path to ground such that the pen or device affects both the mutual capacitance and the self-capacitance. When the pen or device is not touched by a person, there is no path to ground and thus the pen or device only effects the mutual capacitance. 
     In addition, the pen or device receives signals from the touch screen via the capacitance coupling to the screen. The signals transmitted by the pen or device to the touch screen are also through the capacitance coupling and affect the signals on the electrodes  85 . 
     As an example, the device  14  or pen  16  is capacitively coupled to the touch screen of the computing device via capacitor Cx 1  and/or capacitor Cx 2 . For example, the pen  16  is coupled to the touch screen via capacitor Cx 1  or capacitor Cx 2  and the device  14  is coupled to the touch screen via capacitors Cx 1  and Cx 2 . For a pen  16  touch, the capacitance of Cx 1  or Cx 2  is about 50 femto-Farads. Depending on the area of the contact surface of the device, the capacitance of Cx 1  and/or Cx 2  will be in the range of 50 femto-Farads to 10 or more pico-Farads. 
     Due to the small capacitance of Cx 1  and/or Cx 2 , the pen  16  generates an effective negative capacitance to enable the drive sense circuits (DSC) detect the presence of the pen. In an embodiment, the effective negative capacitance is about −50 femto-Farads. To create the effective negative capacitance, an operational amplifier configuration as shown in  FIG. 6A  may be used. 
       FIG. 6A  is a schematic block diagram of an embodiment of an operational amplifier configuration  120  that includes an operational amplifier (op-amp), a capacitor (C), and a pair of resistors (R 1  &amp; R 2 ). The operational amplifier configuration receives two inputs: a sense signal  88  and a reference input  89 . The sense signal  88 , as described in greater detail below, is received from one or more drive sense circuits (DSCs) of the touch screen display. The reference input  89  may be one of a variety of inputs. In an example, the reference input  89  is a common ground. In another example, the reference input  89  is a reference signal (e.g., voltage or current). In a further example, the reference input  89  is an analog representation of data to be transmitted to the touch screen display. In this embodiment, the negative capacitance is approximately equal to −C*R 2 /R 1 . 
     When the pen tip touches the screen, the operational amplifier configuration  120  creates Vo to be a scaled and inverted version of the Vs. By varying the magnitude of Vo, the capacitive coupling between the pen and the touch screen can be varied. For example, by having Vs at 1 volt and generating Vo to be 15 volts, capacitance Cx 1  and/or Cx 2  is increased by about 16 times. 
       FIG. 7  is a schematic block diagram of an embodiment of a pen  16  that includes a first AC coupling circuit  80 , a sense-regulation circuit  82 , a response circuit  84 , and a second AC coupling circuit  86 . The touch screen sensor array  100  includes row and column electrodes and drive sense circuits (DSC) driving and sensing each electrode. 
     The DSC drives a sensor drive signal  104  on to the electrode  85  to produce a sense signal  88 . The sensor drive signal  104  may be an analog signal or a digital signal. In an embodiment, the sensor drive signal  104  is an analog signal and the DSC functions as described in co-pending patent application entitled, “DRIVE SENSE CIRCUIT WITH DRIVE-SENSE LINE”, having a serial number of Ser. No. 16/113,379, and a filing date of Aug. 27, 2018. Note that, if the touch screen sensor array  100  does not include DSCs, then the touch screen functions in a ring-back mode (e.g., the pen&#39;s transmit signal  98  affects the sense signal  88 , which can be detected by the touch screen sensor array as a touch of the pen with no extra data being communicated there between). 
     The first AC coupling circuit  80  is operable to receive a sense signal  88  from the touch screen sensor array  100 . The first AC coupling circuit  80 , which will be described in greater detail with reference to  FIG. 8 , provides the sense signal  88  to the sense-regulation circuit  82 . The sense-regulation circuit  82  is operable to compare the sense signal  88  to a reference signal  90  (e.g., a voltage reference, a current reference) to produce a comparison signal  92 . As such, the comparison signal  92  is a representation of the sense signal  88  (e.g., inverted signal, non-inverted signal, integrated signal, etc.). 
     The sense-regulation circuit  82  then generates a regulation signal  94  based on the comparison signal  92  to regulate the receiving of the sense signal  88 . By regulating the receiving of the sense signal  88  (e.g., keeping it a desired voltage level, a desired current level, etc.), the resulting comparison signal  92  is reflective of changes within the sense-regulation circuit  82  to keep the sense signal  88  at the desired voltage and/or current level with respect to the reference signal  90 . If data is embedded in the sense signal  88 , the comparison signal  88  will include a representation of that data and a representation of the sense signal  88 . If there is not embedded data, the comparison signal  88  only includes the representation of the sense signal  88 . 
     The response circuit  84  is operable to generate a transmit signal  98  based on the comparison signal  92  and data  96 . In an embodiment, the response circuit  84  includes a processing circuit or processing module to combine the comparison signal  92  and the data  96 . For example, the response circuit  84  modulates the data  96  on to the comparison signal  92  to produce the transmit signal  98 . As a specific example, the response circuit performs one or more of Amplitude Shift Keying (ASK), Phase Shift Keying (PSK), and Amplitude Modulation (AM) to produce the transmit signal  98  from the comparison signal  92  and the data  96 . In an embodiment, the response circuit is a signal generator as described in co-pending patent application entitled, “RECEIVE ANALOG TO DIGITAL CIRCUIT OF A LOW VOLTAGE DRIVE CIRCUIT DATA COMMUNICATION SYSTEM”, having a serial number of Ser. No. 16/266,953, and a filing date of Feb. 4, 2019. 
     The second AC coupling circuit  86  is operable to transmit the transmit signal  98  to the touch screen sensor array  100 . For example, the second AC coupling circuit  86  sends the transmit signal to the electrode  85  via the capacitive coupling. The DSC circuit senses the transmit signal  98  on the electrode as a change in the sensor drive signal  104 , where the change is an impedance change, a voltage change, a current change, a phase change, a frequency change, and/or a magnitude change. The DSC provides the detected change to the touch screen processing module  81  (of  FIG. 3 ), which processes the signal to determine a touch of the pen and to further interpret the data contained in the transmit signal. 
     In an embodiment, there is no data  96 . As such, the transmit signal  98  includes the comparison signal  92 , which is a representation of the sense signal  88 . As such, the pen  16  is provided a regulated ring-back signal to the touch screen. In another embodiment, the transmit signal  98  includes the comparison signal  92  and the data  96 , but the touch screen sensor array  100  does not include DSCs. In this embodiment, the data  96  embedded in the transmit signal  98  is ignored by the touch screen sensor array  100  and the touch screen sensor array  100  processes the comparison signal  92  contained in the transmit signal  98 . 
       FIG. 8  is a schematic block diagram of another embodiment of a pen  16  that includes a battery  110 , one or more data source circuits  115 , circuitry  112 , a conductive pen tip  114 , and a conductive pen shell &amp; cone  116 . The conductive pen tip  114  is composed of one or more conductive materials and is electrically isolated from the conductive shell &amp; cone  116 , which is also composed on one or more conductive materials (e.g., metal traces in a plastic substrate, metal, ITO, a conductive polymer, etc.). In addition, the conductive pen tip  114  is at least partially physically contained within the cone part of the conductive pen shell &amp; cone  116 . In another embodiment, the conductive pen tip  114  is electrically coupled via a coupling circuit to the conductive shell &amp; cone  114 . For example, the coupling circuit is one or more of a wire, a capacitor, and an inductor. 
     The circuitry  112 , which will be described in greater detail with reference to  FIG. 9 , is coupled to the conductive pen tip  114  and to the conductive shell &amp; cone  116 . In one embodiment, the first AC coupling circuit  80  is the conductive pen tip  114  and the second AC coupling circuit  86  is the conductive pen shell and cone  116 . In another embodiment, the first AC coupling circuit  80  is a conductive pen shell and cone  116  and the second AC coupling circuit  86  is the conductive pen tip  114 . 
     The data source circuit  115  provides the data  96  to the circuitry  112 , which includes the sense-regulation circuit  82  and the response circuit  84 . In an embodiment, the data source circuit  115  is a pressure sensor coupled to a conductive pen tip  114 . The pressure sensor measures pressure on the conductive pen tip when the conductive pen tip is in physical contact with the touch screen. The pressure sensor converts the measured pressure into the data  96 . 
     In another embodiment, the data source circuit  115  is an orientation sensor (e.g., accelerometer, gyroscope, axial capacitance sensor array, etc.) that is measures three-dimensional orientation of on the pen  16  when the pen is in physical contact with the touch screen. The orientation sensor then converts the measured three-dimensional orientation into the data  96 . 
       FIG. 9  is a schematic block diagram of an embodiment of the circuitry  112  of the pen  16  that includes the sense-regulation circuit  82  and the response circuit  84 . The sense-regulation circuit  82  includes an operational amplifier configuration  120  (which may be implemented as shown in  FIG. 6A  or in a different manner), a regulation circuit  122 , and a dependent current source  124 . The response circuit  84  includes a processing module  126  and a drive circuit  128 . The processing module  126  is configured to provide, or include, a digital to analog converter  130  and a modulator  132 . 
     In an example of operation, the operational amplifier  120  receives the sense signal  88  at its negative input and a reference signal  90  at its positive input to generate the comparison signal  92 . The regulation circuit  122  generates a regulation signal  94  from the comparison signal  92 . The dependent supply source  124  (e.g., a dependent current source, a dependent voltage supply, a bidirectional dependent current source, a bidirectional dependent voltage supply, etc.) generates an adjustment signal  125  such that the voltages inputted in to the operational amplifier  120  remain substantially equal, which provides the regulating of receiving the sense signal. 
     As a specific example, the sense signal  88  is a sinusoidal signal having a frequency in the range of tens of Kilo-Hertz to tens of Giga-Hertz and the reference signal  90  is a DC signal (e.g., a DC voltage reference or a DC current reference). The output of the operational amplifier  120  (i.e., the comparison signal  92 ) will correspond to the inversion of the sense signal  88  (e.g., an inverted sinusoidal signal). The regulation circuit  122  (which may be a capacitor, resistor, wire, combination of capacitors and/or resistors, an integrator, etc.) and the dependent supply source  124  provide the gain for the feedback loop of the sense-regulation circuit  82  to generate the regulation signal  94  so that the comparison signal  92  does not get clipped (e.g., its magnitude is limited by the power supply voltage). 
     As another specific example, the sense signal  88  is a digital pulse train having a clock rate in the range of tens of Kilo-Hertz to tens of Giga-Hertz and the reference signal  90  is a DC signal. The output of the operational amplifier  120  (i.e., the comparison signal  92 ) will correspond to the inversion of the sense signal  88  (e.g., an inverted digital pulse train). The regulation circuit  122  and the dependent supply source  124  provide the gain for the feedback loop of the sense-regulation circuit  82  to generate the regulation signal  94  so that information in the digital pulse train is retained by the comparison signal  92 . 
     Returning to the example of operation, the digital to analog converter  130  converts the data  96  into an analog data  97 . The modulator  132  modulates the analog data  97  with the comparison signal  92  to produce an analog outbound data signal  134 . The drive circuit  128  (e.g., a driver, a unity gain amplifier, a voltage to current converter, a current to voltage converter, etc.) creates the transmit signal  98  from the analog outbound data signal  134 . As an example, the transmit signal  98  is a higher power version (e.g., more voltage and/or more current) of the analog output data signal  134 . 
     The modulator  132  can modulate the analog data  97  with the comparison signal  92  in a variety of ways. For example, the modulator  132  uses Amplitude Shift Keying (ASK) to modulate the analog data  97  with the comparison signal  92 , which is done at an “n” cycle by cycle basis of the comparison signal, wherein “n” is an integer equal to or greater than 1. As another example, the modulator  132  uses Phase Shift Keying (PSK) to modulate the analog data  97  with the comparison signal  92 , which is done at the “n” cycle by cycle basis of the comparison signal. As yet another example, the modulator  132  uses a combination of ASK and PSK to modulate the analog data  97  with the comparison signal  92 , which is done at the “n” cycle by cycle basis of the comparison signal. As a further example, the modulator  132  uses Amplitude Modulation (AM) to modulate the analog data  97  with the comparison signal  92 , which is done at the clock rate of the data  96 . 
       FIG. 10  is a schematic block diagram of an example of ring-back signaling with no data (e.g., the data is a null set for ring-back only touch sensing operation). As shown, the sense signal  88  is a sinusoidal signal having a frequency in the range of tens of Kilo-Hertz to tens of Giga-Hertz and the reference signal  90  (not shown) is a DC signal. The comparison signal  92  is the inversion of the sense signal (e.g., an inverted sinusoidal signal), which may have the same or different peak to peak value as the sense signal (shown to be less than). The transmit signal  98  is a higher power version of the comparison signal  92 . 
       FIG. 11  is a schematic block diagram of an example of ring-back with data  96  that is modulated with the comparison signal using ASK. As shown, the sense signal  88  is a sinusoidal signal and the comparison signal  92  is an inversion of the sense signal. The data  96  is shown as four bits, those being 1, 1, 0, 1. For this example of ASK, the 1&#39;s are represented as a first magnitude of the transmit signal and the 0&#39;s are represented as a second magnitude of the transmit signal  98 , where the first magnitude is greater than the second magnitude. 
       FIG. 12  is a schematic block diagram of another embodiment of the circuitry  112  of the pen  16  that includes a sense-regulation circuit  82 - 1  and a response circuit  84 - 1 . The sense-regulation circuit  82 - 1  includes the operational amplifier configuration  120  (which may be implemented as shown in  FIG. 6A  or in a different manner), an analog to digital converter  140 , a digital to analog converter  142 , and the dependent supply source  124 . As used herein, a suffix of a reference number indicates that the referenced component is similar to a like-referenced component with a different suffix, where an overall operation of the liked-reference number components is similar, but the liked-reference number components operate on different data, operate in different domains (e.g., analog or digital, time or frequency), and/or perform in a different manner to achieve a similarly desired result. 
     The operational amplifier  120  generates an analog comparison signal  92 - 1  based on the sense signal  88  and the reference signal  90 . The analog to digital converter  140  converts the analog comparison signal  92 - 1   a  into the comparison signal  92 - 1 . The digital to analog converter  142  converts the comparison signal  92 - 1  into the regulation signal  94 - 1 . The dependent supply source  124  generates the adjustment signal  125  based on the regulation signal. 
     The processing module  126  of the response circuit  84 - 1  digitally modulates the data  96  with the digital comparison signal  92 - 1  to produce a digital outbound data signal  134 - 1 . The drive circuit  128  includes a digital to analog converter  144 , which converts the digital outbound data signal  134 - 1  into the transmit signal  98 . 
       FIG. 13  is a schematic block diagram of another embodiment of a pen  16 - 1  that includes a battery  110 , one or more data source circuits  115 , circuitry  150 , a conductive pen tip  114 , and a pen shell &amp; cone  116 - 1  (which may or may not be conductive). The circuitry  150 , which will be described in greater detail with reference to  FIG. 14 , is coupled to the conductive pen tip  114  for transmitting and receiving data from the touch screen. The data source circuit  115  provides the data  96  to the circuitry  150 , which includes a sense-regulation circuit  82 - 2 . 
       FIG. 14  is a schematic block diagram of another embodiment of the circuitry  150  of the pen  16 - 1 . The circuitry  150  includes a processing circuit  150  and the sense-regulation circuit  82 - 2 . 
     In an example of operation, the AC coupling circuit  80 - 1  receives the sense signal  88  from the touch screen sensor array  100 . In one embodiment, the AC coupling circuit  80 - 1  is the conductive pen tip  114 . In another embodiment, the AC coupling circuit  80 - 1  is the conductive pen shell and cone  116 . 
     The sense-regulation circuit  82 - 2  receives the sense signal  88  and receives a representation  160  of the data  96  from the processing circuit  152 . The processing circuit  152  will be described in greater detail with reference to  FIG. 17 . The sense-regulation circuit  82 - 2  generates a comparison signal  92 - 2  based on the sense signal  88  and the representation  160  of the data  96 . The sense-regulation circuit  82 - 2  then generates a regulation signal  94 - 2  to regulate receiving of the sense signal and transmitting of a transmit signal  98 - 1 . The AC coupling circuit transmits the transmit signal  98 - 1  to the touch screen. 
     In another embodiment, the sense-regulation circuit  82 - 2  generates a separate ring back signal based on the sensed signal. A second AC coupling circuit  86  of the pen  16 - 1  transmits the ring-back signal to the touch screen. 
       FIG. 15  is a schematic block diagram of another embodiment of the sense-regulation circuit  82 - 2  of the pen  16 - 1 . The sense-regulation circuit  82  includes the operational amplifier configuration  120  (which may be implemented as shown in  FIG. 6A  or in a different manner), the regulation circuit  122 , and the dependent current source  124 . 
     In an example of operation, the operational amplifier  120  receives the sense signal  88  at its negative input and the representation  160  of the data  96  at its positive input to generate the comparison signal  92 - 2 . The regulation circuit  122  generates a regulation signal  94 - 2  from the comparison signal  92 - 2 . The dependent supply source  124  generates an adjustment signal  125 - 2  such that the voltages inputted into the operational amplifier  120  remain substantially equal, which provides the regulating of receiving the sense signal  88  and regulation of transmitting the transmit signal  98 . 
     As a specific example, the sense signal  88  is a sinusoidal signal having a frequency in the range of tens of Kilo-Hertz to tens of Giga-Hertz and the representation  160  of the data  96  is a second sinusoidal signal having a different frequency than that of the sense signal. The output of the operational amplifier  120  (i.e., the comparison signal  92 ) correspond to a difference between the sense signal  88  and the representation  160  of the data  96 . The regulation circuit  122  and the dependent supply source  124  provide the gain for the feedback loop of the sense-regulation circuit  82  to generate the regulation signal  94  so that the comparison signal  92  does not get clipped. As such, the comparison signal  92 - 2  includes a representation (e.g., includes the same information but may be of a different magnitude, phase, or domain) of the sense signal  88  and of the representation  160  of the data  96 . 
       FIG. 16  is a schematic block diagram of another embodiment of the sense-regulation circuit  82 - 2   a  and a receive digital processing module  161  of the pen  16 - 1 . The sense-regulation circuit  82 - 2   a  includes the operational amplifier configuration  120  (which may be implemented as shown in  FIG. 6A  or in a different manner), the analog to digital converter  140 , the digital to analog converter  142  and the dependent current source  124 . 
     In an example of operation, the operational amplifier  120  receives the sense signal  88  at its negative input and the representation  160  of the data  96  at its positive input to generate analog comparison signal  92 - 2 . The analog to digital converter  140  converts the analog comparison signal  92 - 2  into a digital comparison signal  92 - 2   a . The digital to analog converter  142  converts the digital comparison signal  92 - 2   a  into the regulation signal  94 - 2   a . The dependent supply source  124  generates an adjustment signal  125 - 2   a  such that the voltages inputted into the operational amplifier  120  remain substantially equal, which provides the regulating of receiving the sense signal  88  and regulation of transmitting the transmit signal  98 . 
     The receive digital processing module  161  receives the comparison signal  92 - 2   a  and extracts, therefrom, receive data. The receive data is regarding interoperation of the touch screen and the pen. For example, the receive data is feedback from touch screen regarding data received from pen. As another example, the receive data is for calibration of the pen for use with the touch screen. As another example, the receive data indicates a set of operations for the pen to use when interacting with the touch screen. 
       FIG. 17  is a schematic block diagram of an embodiment of a data source circuit  115  and a processing circuit  152  of a pen  16  and/or  16 - 1 . The data source circuit  115  includes a sensing element  170  (e.g., a transducer, switch, circuit, combination, etc.) and a data sense circuit  172 . The processing circuit  152  includes a processing module  172  and a digital to analog converter  174 . 
     In an example of operation, the sensing element sense a condition  176  of the pen. For example, the sensing element  170  senses pressure, tilt, color selection, erasure mode selection, other environmental condition, and/or other operational condition of the pen. The sensing element  170  generates a condition signal  178  based on the sensed condition  176  of the pen. The data sense circuit  172  generates the data  96  based on the condition signal  178  and a reference signal  180 . The data sense circuit  172  will be described in greater detail with reference to  FIG. 18 . 
     The processing module  172  generates digital outbound data  182  based on the data  96 . For example, the processing module  172  adjust formatting of the data  96  (e.g., non-return to zero, return to zero, Manchester, etc.), adjust data rate of the data  96 , level shifting of the data, etc. The digital to analog converter  174  converts the digital outbound data  182  into the representation  160  of the data  96 . 
       FIG. 18  is a schematic block diagram of an embodiment of a data sense circuit  172  that includes an operational amplifier configuration  120 - 2  (which may be implemented as shown in  FIG. 6A  or in a different manner), a regulation circuit  122 - 2 , and a dependent supply source  124 - 2 . In an example of operation, the operational amplifier  120 - 2  receives the condition signal  178  at its negative input and a reference signal  180  at its positive input to generate the data  96 . 
     The regulation circuit  122 - 2  generates a regulation signal  94 - 3  from the data  96 . The dependent supply source  124  (e.g., a dependent current source, a dependent voltage supply, a bidirectional dependent current source, a bidirectional dependent voltage supply, etc.) generates an adjustment signal  125 - 3  such that the voltages inputted in to the operational amplifier  120 - 2  remain substantially equal, which provides the regulating of receiving the sense signal. 
     As a specific example, the condition signal  178  is a non-sinusoidal signal having a frequency in the range of tens of Kilo-Hertz to tens of Giga-Hertz and the reference signal  180  is a DC signal (e.g., a DC voltage reference or a DC current reference). The output of the operational amplifier  120 - 2  (i.e., the data  96 ) will correspond to the inversion of the condition signal  178 . The regulation circuit  122 - 2  (which may be a capacitor, resistor, wire, combination of capacitors and/or resistors, an integrator, etc.) and the dependent supply source  124 - 2  provide the gain for the feedback loop of the data sense circuit  172  to generate the regulation signal  94 - 3  so that the data  96  does not get clipped (e.g., its magnitude is limited by the power supply voltage). 
       FIG. 19A  is a schematic block diagram of an embodiment of a device  14  that includes a sense-regulation circuit  82 - 3 , an AC coupling circuit  200 , an inbound data processing module  204 , an outbound data processing module  206 , and a processing module  203 . The AC coupling circuit  200  provides a communication path for the device  14  with the touch screen sensor array  100  of the touch screen  12  of the computing device  10 . Note that the inbound data processing module  204 , the outbound data processing module  206 , and the processing module  203  may be implemented in the same processing circuit, in different processing circuits, or a combination thereof. 
     For data communication from the computing device  10  to the device  14 , the device receives a sense signal  88  via the AC coupling circuit  200 . The sense-regulation circuit  82 - 3  processes the sense signal  88  in light of a representation  210  of transmit data  208  (e.g., data from the processing module  203 ) to produce a receive error signal  212 . As will be described in greater detail with reference to  FIGS. 20 and 21 , the receive error signal includes a combination of the comparison signal  92 - 3  and the representation  210  of the transmit data  210 . 
     The outbound data processing module  206  processes the receive error signal  212  and produces, therefrom, receive data  214 . For example, the outbound data processing module  214  includes a filtering circuit and digital conversion circuit. The filtering circuit bandpass filters the receive error signal  212  to substantially pass, unattenuated, the comparison signal  92 - 3  (which is a representation of the sense signal  88 ) and to attenuate other components of the receive error signal, including the representation  210  of the transmit data. For further examples of an outbound data processing module  214  refer to co-pending patent application entitled, “ANALOG TO DIGITAL CONVERSION CIRCUIT WITH VERY NARROW BANDPASS DIGITAL FILTERING”, having a serial number of Ser. No. 16/365,169, and a filing date of Mar. 26, 2019. 
     The processing module  203  processes the receive data  214  to determine a command, a data request, or other type of digital communication from the computing device  10 . In addition, the processing module  203  generates transmit data  208  for sending to the computing device  10 . 
     The inbound data processing module  204  converts the transmit data  208  into the representation  210  of the transmit data  208 . The inbound data processing module  204  may be implemented as a signal generator, which is described in co-pending patent application entitled, “RECEIVE ANALOG TO DIGITAL CIRCUIT OF A LOW VOLTAGE DRIVE CIRCUIT DATA COMMUNICATION SYSTEM”, having a serial number of Ser. No. 16/266,953, and a filing date of Feb. 4, 2019. 
     The sense-regulation circuit processes the representation  210  of the transmit data  208  to produce a transmit signal  98 - 3 . The AC coupling circuit  200  sends the transmit signal  98 - 3  to the touch screen sensor array  100 . 
       FIG. 19B  is a schematic block diagram of an embodiment of a device  14  that includes a sense-regulation circuit  82 - 3 , an AC coupling circuit  200 , an inbound data processing module  204 , an outbound data processing module  206 , and a communication circuit  202 . The AC coupling circuit  200  provides a communication path for the device  14  with the touch screen sensor array  100  of the touch screen  12  of the computing device  10 . The communication circuit  202  provides a communication path with another computing device  215 . In an embodiment, the device  14  functions as a full duplex communication medium between the touch screen of the computing device  10  and a communication port of the other computing device  215 . 
     For data communication from the computing device  10  to the other computing device  215 , the device receives a sense signal  88  via the AC coupling circuit  200 . The sense-regulation circuit  82 - 3  processes the sense signal  88  in light of a representation  210  of transmit data  208  (e.g., data from the other computing device  215  to the computing device  10 ) to produce a receive error signal  212 . As will described in greater detail with reference to  FIGS. 20 and 21 , the receive error signal includes a combination of the comparison signal  92 - 3  and the representation  210  of the transmit data  210 . 
     The outbound data processing module  206  processes the receive error signal  212  and produces, therefrom, receive data  214 . For example, the outbound data processing module  214  includes a filtering circuit and digital conversion circuit. The filtering circuit bandpass filters the receive error signal  212  to substantially pass, unattenuated, the comparison signal  92 - 3  (which is a representation of the sense signal  88 ) and to attenuate other components of the receive error signal, including the representation  210  of the transmit data. For further examples of an outbound data processing module  214  refer to co-pending patent application entitled, “ANALOG TO DIGITAL CONVERSION CIRCUIT WITH VERY NARROW BANDPASS DIGITAL FILTERING,” having a serial number of Ser. No. 16/365,169, and a filing date of Mar. 26, 2019. 
     The communication circuit  202 , which may be a USB (Universal Serial Bus) interface, a Lighting interface, a serial interface such as I3C/I2C, NFC (Near Field Communication), Bluetooth, Wi-Fi, etc., sends the receive data  214  to the other computing device  215 . In addition, the communication circuit  202  receives transmit data  208  from the other computing device  215  and provides it to the inbound data processing module  204 . 
     The inbound data processing module  204  converts the transmit data  208  into the representation  210  of the transmit data  208 . The inbound data processing module  204  may be implemented as a signal generator, which is described in co-pending patent application entitled, “RECEIVE ANALOG TO DIGITAL CIRCUIT OF A LOW VOLTAGE DRIVE CIRCUIT DATA COMMUNICATION SYSTEM,” having a serial number of Ser. No. 16/266,953, and a filing date of Feb. 4, 2019. 
     The transmit data  208  includes data regarding the other computing device and/or regarding the device, such as:
         identification of the computing device (e.g., serial number, IP address, cell phone number, user information, etc.);   identification of a type of computing device (e.g., cell phone, mouse, keyboard, ruler, laptop, etc.);   location information regarding the computing device with respect to the touch screen;   time synchronization information;   application activation information; and   request for touch screen to provide graphical user interface for the computing device.       

     The sense-regulation circuit processes the representation  210  of the transmit data  208  to produce a transmit signal  98 - 3 . The AC coupling circuit  200  sends the transmit signal  98 - 3  to the touch screen sensor array  100 . 
       FIG. 20  is a schematic block diagram of an embodiment of a sense-regulation circuit  82 - 3  of a device  14 . The sense-regulation circuit  82 - 3  includes an operational amplifier  120 - 3 , a regulation circuit  122 - 3 , and the dependent current source  124 - 3 . 
     In an example of operation, the operational amplifier  120 - 3  receives the sense signal  88  at its negative input and the representation  210  of the transmit data  208  at its positive input to generate the comparison signal  92 - 4 . The regulation circuit  122 - 3  generates a regulation signal  94 - 4  from the comparison signal  92 - 4 . The dependent supply source  124 - 3  generates an adjustment signal  125 - 4  such that the voltages inputted into the operational amplifier  120 - 3  remain substantially equal, which provides the regulating of receiving the sense signal  88  and regulation of transmitting the transmit signal  98 - 3 . 
     As a specific example, the sense signal  88  is a sinusoidal signal having a frequency in the range of tens of Kilo-Hertz to tens of Giga-Hertz and the representation  210  of the transmit data  208  is a second sinusoidal signal having a different frequency than that of the sense signal. The output of the operational amplifier  120 - 3  (i.e., the comparison signal  92 - 4 ) correspond to a difference between the sense signal  88  and the representation  210  of the transmit data  208 . The regulation circuit  122 - 3  and the dependent supply source  124 - 3  provide the gain for the feedback loop of the sense-regulation circuit  82 - 3  to generate the regulation signal  94 - 4  so that the comparison signal  92 - 4  does not get clipped. As such, the comparison signal  92 - 4  includes a representation (e.g., includes the same information but may be of a different magnitude, phase, or domain) of the sense signal  88  and of the representation  210  of the transmit data  208 . 
       FIG. 21  is a schematic block diagram of another embodiment of a sense-regulation circuit  82 - 4  of a device  14 . The sense-regulation circuit  82 - 4  includes the operational amplifier configuration  120  (which may be implemented as shown in  FIG. 6A  or in a different manner), the regulation circuit  122 , the dependent supply source  124 , and a by-pass line, which couples the representation  210  of the transmit data  208  to a second AC coupling circuit  200 - 2 . The operational amplifier  120 , the regulation circuit  122 , and the dependent supply source  124  function as previously described to generate the comparison signal  92 - 5  from the sense circuit  88  and a reference signal  212 . In this embodiment, the receive error signal  212  corresponds to the comparison signal  92 - 5 . 
       FIG. 22  is a schematic block diagram of an embodiment of a touch screen to touch screen communication between two computing devices  10  and  10 - 1 . Both computing devices include a touch screen  12 . When the computing devices are face to face, the computing devices are able to communicate via their respective touch screens. 
     To accomplish this, each computing device includes the circuitry of device  14 . The circuitry of device  14  may be integrated into the touch screen control circuit or it may be a stand-alone circuit. When the computing devices are face to face, they can utilize a plurality of patterns (frequency and/or electrode enable) to communication data there between. One or more patterns may be used to set up the communication and the patterns to be used for conveying data. 
       FIG. 23A  is a schematic block diagram of an example of a frequency pattern representing data that is embedded in the sense signal and/or data that is embedded in the transmit data. In this example, a frequency pattern is established over time to represent data. As shown, a first frequency corresponds to a logic value of 0 and a second frequency corresponds to a logic value of 1. The pattern can be interpreted by the inbound and/or outbound processing modules to convert the pattern into data and/or data into the pattern. 
       FIGS. 23B-23F  are schematic block diagrams of examples of electrode patterns representing data.  FIG. 23B  illustrates row electrodes  232  and column electrodes  230  being in an orthogonal relationship. In the examples of  FIG. 23C through 23F , thicker lines for the electrodes indicate that the electrode is enable (e.g., a DSC is drive a sensing signal on the electrode) and thinner lines for the electrodes indicate that the electrode is not enable (e.g., a DSC is not drive a sensing signal on the electrode). 
       FIG. 23C  illustrates a row pattern where all column electrodes are not enabled and some of the row electrodes are enabled. The patterning of which row electrodes to enable and disable for a data message may be done in a bar code style. A pattern may be used to represent one bit of data, one byte of data, a specific message, or a specific command. As is readily apparent, a large number of patterns can be obtained by selectively enabling and disabling row electrodes. 
       FIG. 23D  illustrates a column pattern where all row electrodes are not enabled and some of the column electrodes are enabled to represent different data.  FIG. 23E  illustrates a row and a column pattern where some of the row electrodes are enabled and some of the column electrodes are enabled.  FIG. 23F  illustrates each row and column electrode representing a bit of data. In this example, there are 8 row electrodes and 8 column electrodes representing 16 bits of data. For the examples of  FIG. 23C through 23F , the row and column electrodes included in a pattern area may encompass the entire touch screen area or a portion thereof. 
       FIG. 24  is a schematic block diagram of an example of a device including a housing  222  and AC coupling circuit  200  of the device  14 . In this embodiment, the circuitry of the device is on the printed circuit board  220 , which is mounted in the housing  222 . The housing  222  may be implemented in a variety of ways. For example, the housing  222  is a case for a phone. As another example, the housing is in the form of a computing mouse. As yet another example, the housing is in the form of a keyboard. 
     The AC coupling circuit  200  is electrically coupled to the printed circuit board  220  and includes a conductive pad that is electrically isolated from the housing  22 . The conductive pad may be implemented in a variety of ways. For example, the conductive pad is a pin. As another example, the conductive pad is an electrode and/or metal trace. As yet another example, the conductive pad is a conductive material having a shape to receive the sense signal from the touch screen and/or to transmit the transmit signal to the touch screen. 
       FIG. 25  is a schematic block diagram of an embodiment of a device  14 - 1  that includes touch screen communication circuits  230 - 1  through  230 - n , a processing module  232 , and a communication circuit  202 . Each of the touch screen communication circuits includes at least one AC coupling circuit that provides electrical connectivity to different drive sense circuits (DSC  1 - n ) of the touch screen sensor array  100  of the touch screen  12  of the computing device  10 . The communication circuit  202  provides a communication path with another computing device  215 . In an embodiment, the device  14 - 1  functions as a full duplex communication medium between the touch screen of the computing device  10  and a communication port of the other computing device  215 . 
     The touch screen communication circuits  230 - 1  through  230 - n  may be implemented in accordance with the circuitry of a pen and/or the circuitry of a device as previously discussed. With multiple touch screen communication circuits, multiple pieces of information can be conveyed between the computing devices  10  and  215 . For example, the location and orientation of the device on the touch screen can be determined based on the information conveyed to the touch screen and which DSCs received the transmit signals. As another example, the multiple pieces of information can be used to determine motion of the device on the touch screen to indicate a gesture-based function or other function. 
     It is noted that terminologies as may be used herein such as bit stream, stream, signal sequence, etc. (or their equivalents) have been used interchangeably to describe digital information whose content corresponds to any of a number of desired types (e.g., data, video, speech, text, graphics, audio, etc. any of which may generally be referred to as ‘data’). 
     As may be used herein, the terms “substantially” and “approximately” provide an industry-accepted tolerance for its corresponding term and/or relativity between items. For some industries, an industry-accepted tolerance is less than one percent and, for other industries, the industry-accepted tolerance is 10 percent or more. Other examples of industry-accepted tolerance range from less than one percent to fifty percent. Industry-accepted tolerances correspond to, but are not limited to, component values, integrated circuit process variations, temperature variations, rise and fall times, thermal noise, dimensions, signaling errors, dropped packets, temperatures, pressures, material compositions, and/or performance metrics. Within an industry, tolerance variances of accepted tolerances may be more or less than a percentage level (e.g., dimension tolerance of less than +/−1%). Some relativity between items may range from a difference of less than a percentage level to a few percent. Other relativity between items may range from a difference of a few percent to magnitude of differences. 
     As may also be used herein, the term(s) “configured to”, “operably coupled to”, “coupled to”, and/or “coupling” includes direct coupling between items and/or indirect coupling between items via an intervening item (e.g., an item includes, but is not limited to, a component, an element, a circuit, and/or a module) where, for an example of indirect coupling, the intervening item does not modify the information of a signal but may adjust its current level, voltage level, and/or power level. As may further be used herein, inferred coupling (i.e., where one element is coupled to another element by inference) includes direct and indirect coupling between two items in the same manner as “coupled to”. 
     As may even further be used herein, the term “configured to”, “operable to”, “coupled to”, or “operably coupled to” indicates that an item includes one or more of power connections, input(s), output(s), etc., to perform, when activated, one or more its corresponding functions and may further include inferred coupling to one or more other items. As may still further be used herein, the term “associated with”, includes direct and/or indirect coupling of separate items and/or one item being embedded within another item. 
     As may be used herein, the term “compares favorably”, indicates that a comparison between two or more items, signals, etc., provides a desired relationship. For example, when the desired relationship is that signal 1 has a greater magnitude than signal 2, a favorable comparison may be achieved when the magnitude of signal 1 is greater than that of signal 2 or when the magnitude of signal 2 is less than that of signal 1. As may be used herein, the term “compares unfavorably”, indicates that a comparison between two or more items, signals, etc., fails to provide the desired relationship. 
     As may be used herein, one or more claims may include, in a specific form of this generic form, the phrase “at least one of a, b, and c” or of this generic form “at least one of a, b, or c”, with more or less elements than “a”, “b”, and “c”. In either phrasing, the phrases are to be interpreted identically. In particular, “at least one of a, b, and c” is equivalent to “at least one of a, b, or c” and shall mean a, b, and/or c. As an example, it means: “a” only, “b” only, “c” only, “a” and “b”, “a” and “c”, “b” and “c”, and/or “a”, “b”, and “c”. 
     As may also be used herein, the terms “processing module”, “processing circuit”, “processor”, “processing circuitry”, and/or “processing unit” may be a single processing device or a plurality of processing devices. Such a processing device may be a microprocessor, micro-controller, digital signal processor, microcomputer, central processing unit, field programmable gate array, programmable logic device, state machine, logic circuitry, analog circuitry, digital circuitry, and/or any device that manipulates signals (analog and/or digital) based on hard coding of the circuitry and/or operational instructions. The processing module, module, processing circuit, processing circuitry, and/or processing unit may be, or further include, memory and/or an integrated memory element, which may be a single memory device, a plurality of memory devices, and/or embedded circuitry of another processing module, module, processing circuit, processing circuitry, and/or processing unit. Such a memory device may be a read-only memory, random access memory, volatile memory, non-volatile memory, static memory, dynamic memory, flash memory, cache memory, and/or any device that stores digital information. Note that if the processing module, module, processing circuit, processing circuitry, and/or processing unit includes more than one processing device, the processing devices may be centrally located (e.g., directly coupled together via a wired and/or wireless bus structure) or may be distributedly located (e.g., cloud computing via indirect coupling via a local area network and/or a wide area network). Further note that if the processing module, module, processing circuit, processing circuitry and/or processing unit implements one or more of its functions via a state machine, analog circuitry, digital circuitry, and/or logic circuitry, the memory and/or memory element storing the corresponding operational instructions may be embedded within, or external to, the circuitry comprising the state machine, analog circuitry, digital circuitry, and/or logic circuitry. Still further note that, the memory element may store, and the processing module, module, processing circuit, processing circuitry and/or processing unit executes, hard coded and/or operational instructions corresponding to at least some of the steps and/or functions illustrated in one or more of the Figures. Such a memory device or memory element can be included in an article of manufacture. 
     One or more embodiments have been described above with the aid of method steps illustrating the performance of specified functions and relationships thereof. The boundaries and sequence of these functional building blocks and method steps have been arbitrarily defined herein for convenience of description. Alternate boundaries and sequences can be defined so long as the specified functions and relationships are appropriately performed. Any such alternate boundaries or sequences are thus within the scope and spirit of the claims. Further, the boundaries of these functional building blocks have been arbitrarily defined for convenience of description. Alternate boundaries could be defined as long as the certain significant functions are appropriately performed. Similarly, flow diagram blocks may also have been arbitrarily defined herein to illustrate certain significant functionality. 
     To the extent used, the flow diagram block boundaries and sequence could have been defined otherwise and still perform the certain significant functionality. Such alternate definitions of both functional building blocks and flow diagram blocks and sequences are thus within the scope and spirit of the claims. One of average skill in the art will also recognize that the functional building blocks, and other illustrative blocks, modules and components herein, can be implemented as illustrated or by discrete components, application specific integrated circuits, processors executing appropriate software and the like or any combination thereof. 
     In addition, a flow diagram may include a “start” and/or “continue” indication. The “start” and “continue” indications reflect that the steps presented can optionally be incorporated in or otherwise used in conjunction with one or more other routines. In addition, a flow diagram may include an “end” and/or “continue” indication. The “end” and/or “continue” indications reflect that the steps presented can end as described and shown or optionally be incorporated in or otherwise used in conjunction with one or more other routines. In this context, “start” indicates the beginning of the first step presented and may be preceded by other activities not specifically shown. Further, the “continue” indication reflects that the steps presented may be performed multiple times and/or may be succeeded by other activities not specifically shown. Further, while a flow diagram indicates a particular ordering of steps, other orderings are likewise possible provided that the principles of causality are maintained. 
     The one or more embodiments are used herein to illustrate one or more aspects, one or more features, one or more concepts, and/or one or more examples. A physical embodiment of an apparatus, an article of manufacture, a machine, and/or of a process may include one or more of the aspects, features, concepts, examples, etc. described with reference to one or more of the embodiments discussed herein. Further, from figure to figure, the embodiments may incorporate the same or similarly named functions, steps, modules, etc. that may use the same or different reference numbers and, as such, the functions, steps, modules, etc. may be the same or similar functions, steps, modules, etc. or different ones. 
     While the transistors in the above described figure(s) is/are shown as field effect transistors (FETs), as one of ordinary skill in the art will appreciate, the transistors may be implemented using any type of transistor structure including, but not limited to, bipolar, metal oxide semiconductor field effect transistors (MOSFET), N-well transistors, P-well transistors, enhancement mode, depletion mode, and zero voltage threshold (VT) transistors. 
     Unless specifically stated to the contra, signals to, from, and/or between elements in a figure of any of the figures presented herein may be analog or digital, continuous time or discrete time, and single-ended or differential. For instance, if a signal path is shown as a single-ended path, it also represents a differential signal path. Similarly, if a signal path is shown as a differential path, it also represents a single-ended signal path. While one or more particular architectures are described herein, other architectures can likewise be implemented that use one or more data buses not expressly shown, direct connectivity between elements, and/or indirect coupling between other elements as recognized by one of average skill in the art. 
     The term “module” is used in the description of one or more of the embodiments. A module implements one or more functions via a device such as a processor or other processing device or other hardware that may include or operate in association with a memory that stores operational instructions. A module may operate independently and/or in conjunction with software and/or firmware. As also used herein, a module may contain one or more sub-modules, each of which may be one or more modules. 
     As may further be used herein, a computer readable memory includes one or more memory elements. A memory element may be a separate memory device, multiple memory devices, or a set of memory locations within a memory device. Such a memory device may be a read-only memory, random access memory, volatile memory, non-volatile memory, static memory, dynamic memory, flash memory, cache memory, and/or any device that stores digital information. The memory device may be in a form a solid-state memory, a hard drive memory, cloud memory, thumb drive, server memory, computing device memory, and/or other physical medium for storing digital information. 
     While particular combinations of various functions and features of the one or more embodiments have been expressly described herein, other combinations of these features and functions are likewise possible. The present disclosure is not limited by the particular examples disclosed herein and expressly incorporates these other combinations.