Patent Publication Number: US-2017371441-A1

Title: Pressure sensor with capacitive shield

Description:
BACKGROUND 
     Display devices are increasing in importance due to the wide-spread use of mobile devices, such as cell phones. There are numerous types of displays including Organic Light-emitting Diode (OLED) displays, Light-emitting Diode (LED) displays and Liquid Crystal Displays (LCD). The displays are used in a wide-range of applications, including consumer devices such as cell phones, gaming devices, watches, etc. The OLEDs use thin-film transistors in a backplane that switch pixels on or off so as to generate images on the display. LCDs, by contrast, typically use a backlight in conjunction with light-modulating properties of liquid crystals. Often the displays include multiple layers of glass. For example, an OLED display assembly can include a cover glass (also called a “window”), an encapsulation glass, and a Low-Temperature Polycrystalline Silicon (LTPS) glass. 
     There are numerous sensor types within the display devices. For example, touch sensors allow a user to touch a cover window of the display in order to select display elements. Capacitive effects of a user&#39;s finger can be detected using mutual capacitance wherein two conductive layers are stacked together with a thin separation there between. The layers can have columns and rows (TX and RX) of conductors and when a finger touches a point on the cover window, a mutual capacitance between the columns and rows is altered and detectable. 
     Pressure sensors also use capacitive effects, but based on a distance change between opposed plates of a capacitor. The pressure sensors are generally located within an inactive area of the cover window or below the display stack/system so as not to interfere with the touch sensors. More specifically, as both touch and pressure sensors use capacitive effects, a capacitance of a user&#39;s finger can be wrongly interpreted by the pressure sensor as a change in distance. Interference between pressure sensors and touch sensors can therefore be problematic and limits areas of the display which can be used for one or the other. 
     Therefore, there exists ample opportunity for improvement in technologies related to pressure sensors. 
     SUMMARY 
     This Summary is provided to introduce a selection of concepts in a simplified form that are further described below in the Detailed Description. This Summary is not intended to identify key features or essential features of the claimed subject matter, nor is it intended to be used to limit the scope of the claimed subject matter. 
     Technologies are described for a pressure sensor that can be included in both active and inactive areas of a display. Typically, a sensing pad of a pressure sensor is not within an active area of the display because interference from a user touch can result in inaccurate pressure sensing results. In one embodiment, a sensing pad can be extended into an active area of the display, but a capacitive shielding layer is placed between the sensing pad and the window substrate so as to block the capacitive effects of a user touch. 
     In another embodiment, the capacitive shielding layer can have gaps therein so as to allow the capacitive effects of a user&#39;s finger to pass to touch sensors that are positioned below the sensing pad. 
     In still another embodiment, the capacitive shielding layer is commensurate with the sensing pad or slightly larger than the sensing pad so as to block interfering signals related to touch from being received by the sensing pad. The pressure sensor can be formed from a plurality of conductive traces and the capacitive shielding layer can include a plurality of conductive traces that overlap with the traces of the pressure sensor. 
     The advantages of the described pressure sensor include the ability of the pressure sensor to extend into the active area of the display so as to provide a more accurate pressure sensor and to increase a usable space of the overall display. 
     As described herein, a variety of other features and advantages can be incorporated into the technologies as desired. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  is a system diagram of a display including a pressure sensor with a capacitive shield to block capacitive effects of a user touch. 
         FIG. 2  is an example of a display according to another embodiment, wherein a capacitive shield is used in conjunction with a pressure sensor. 
         FIG. 3  is an example of a display according to another embodiment, wherein a capacitive shield includes spaced-apart conductive traces that align with sensing pads of the pressure sensor. 
         FIG. 4  shows example layers of traces used for touch sensors, sensing pads of a pressure sensor and a capacitive shielding layer. 
         FIG. 5  shows an embodiment of sensing pads of a pressure sensor divided into different areas and possible configurations of the capacitive shielding layer. 
         FIG. 6  is a flowchart of a method according to one embodiment for using a display including a pressure sensor. 
         FIG. 7  is a diagram of an example computing system in which some described embodiments can be implemented. 
     
    
    
     DETAILED DESCRIPTION 
     As described herein, various technologies can be applied to pressure sensors. It is desirable to have pressure sensors be extendible into an active area of a display, rather than have a designated inactive area for pressure sensors, which could limit the size of the display panel. 
       FIG. 1  is a display device (or assembly)  100  that can receive touch input and detect an amount of force thereon through a user press on a cover window  102 . The display  100  can be used in a wide-range of applications, including consumer devices, such as cell phones, gaming devices, watches, etc. As shown at  110  generally, the display device  100  is made up of numerous layers, which can include one or more of the following: a glass layer or a substrate layer (e.g., plastics or other transparent materials), a polarizing layer, a compression layer, adhesive layers and a pressure sensor layer, all of which are described further below. 
     In this embodiment, the specific layers for a portion of the display are shown at  120 . The specific layers include a window substrate  130 , a reference ground  140 , a compression region  150 , a (pressure) sensing pad  160 , a display substrate  170 , and a capacitive shielding layer  171 . It should be understood that at other locations in the display, the layers can be different. The window substrate  130  is often called a “cover” glass and can be made of glass, acrylic, polycarbonate, a variety of plastic materials, or other transparent materials. 
     The reference ground  140  is a layer of electrically conductive material, such as copper or Indium Tin Oxide (ITO), and can be coupled directly to the display substrate  170 . In alternative embodiments, there can be one or more intermediate layers between the display substrate  170  and the reference ground layer  140 . The reference ground layer is generally on an opposite side of the compression region  150  from the sensing pads  160  and can be positioned at other locations, such as embedded within the display substrate  170  or below the display substrate. The compression region  150  can be a compressible adhesive, such as a clear optical adhesive, a polymer, or a combination of an adhesive and a polymer. The compression region can deform and spring back based on a pressure exerted on the window substrate  130 . For example, if a user presses on the window substrate  130 , such pressure exerts a downward force on the compression region. The compression region  150  then compresses such that its width becomes less so that a distance between the reference ground  140  and the sensing pad  160  is reduced. Correspondingly, a capacitance formed by the reference ground layer  140  and the sensing pad  160  also changes. The amount of capacitance change corresponds directly to the force applied. As such, an amount of pressure exerted on the window substrate  130  by the user is detectable. 
     The sensing pad  160  is made of an electrically conductive material, such as copper or transparent conductive material, such as ITO. Additionally, the sensing pad  160  is coupled to a controller (not shown in this figure) so that the controller can read a capacitance change formed between the reference ground  140  and the sensing pad  160 . The sensing pad  160  can be below the window substrate  130  and includes a plurality of individual conductive lines or traces, such as is shown at  162 , with gaps, such as shown at  164  between the traces. The display substrate  170  can be an appropriate substrate for implementing OLED displays, including active-matrix organic light-emitting diode (AMOLED), LED displays, LCDs, etc. As such, the display substrate  170  can be formed from multiple layers of glass or other substrates, such as plastic. For example, an OLED display can be formed from an encapsulation glass and an LTPS glass. Other combinations can be used. The sensing pad  160  and the reference ground  140 , together form a pressure sensor  161 . 
     Touch sensors  163  include individual touch sensing pads or area  165  that are spaced apart. The touch sensors  163  receive capacitive touch signals  185  transmitted by a user touch, shown generally at  180 . The touch sensors  163  are formed from conductive material, such as copper and can detect mutual capacitance change so as determine a location of the user touch. 
     A capacitive shielding layer  171 , which is also, more generically, called a shield or guard layer, is a conductive layer (e.g., made of copper, ITO or other conductive material) that can be coupled to ground or any desired voltage level. The capacitive shielding layer  171  is aligned with the sensing pads  160  so as to act as an electrical shield for the sensing pads. For example, the capacitive shielding layer  171  can include individual conductive lines or traces, such as is shown at  172 , which overlap the traces of the sensing pad  160 . The width of the traces of the capacitive shielding layer  171  can be a first width, shown at W 1 . The width of the traces of the sensing pad  160  is shown as a second width, W 2 . Generally, the width W 1  is greater than the width W 2  so that the capacitive shielding layer  171  can adequately block undesirable electrical input signals. For example, as shown at  180 , the user can touch the window substrate  130  so as to select an icon or perform some other user interface feature. Such a touch of the user interface generates capacitive signals, shown by arrows  185 . Some of the capacitive signals are blocked by the capacitive shielding layer  171  while other capacitive signals pass through the gaps  164  so as to reach the touch sensors  163 . By shielding the capacitive signals  185  from the sensing pads  160 , the pressure sensor  161  can obtain a more accurate pressure reading without interference from the capacitive touch signals. Additionally, the sensing pads  160  of the pressure sensor  161  can be extended into either an inactive region  190  of the display or an active region  192  so as to provide a greater flexibility in terms of location over past pressure sensors. A non-conductive passivation layer  173  is positioned between the sensing pad  160  and the capacitive shielding layer  171  so as to prevent current flow there between. 
       FIG. 2  is an example of a display device (or assembly)  200  according to another embodiment, wherein a capacitive shield is used in conjunction with a pressure sensor. In this embodiment, a window substrate  210  is a transparent material, such as glass, for displaying elements on the display device  200  and for receiving user touch input. A capacitive shielding layer  220  is positioned below the window substrate  210  and can be coupled thereto or there can be one or more intermediate layers between the capacitive shielding layer  220  and the window substrate  210 . The capacitive shielding layer  220  is directly above a sensing pad  230  of a pressure sensor  232 , which is formed, in part, by the sensing pads  230  and a reference ground layer  234 . A non-conductive layer  221  can be positioned between the capacitive shielding layer  220  and the sensing pad  230 , for the reasons described above. The reference ground layer  234  can be positioned on top of a display substrate  240  that includes an encapsulation layer  242  and an LTPS layer  244 . The pressure sensor  232  measures a capacitance value  238  between the sensing pad  230  and the reference ground layer  234 . Both the encapsulation layer  242  and LTPS layer  244  can be formed of glass, and bound together using a frit layer  246 . Display traces  248  are positioned between the encapsulation layer  242  and the LTPS layer  244  and are used in conjunction with other display elements to project images through the window substrate  210 . 
     Touch traces  250  are positioned on the encapsulation layer  242 . The touch traces  250  can receive capacitive signals from a user touch on the window substrate  210  so as to determine a position of the user&#39;s touch. A compression region  260  is positioned between the sensing pad  230  and the reference ground layer  234 . A polarizer layer  262  is positioned between the compression region  260  and the touch traces  250 . The polarizer layer  262  enhances the contrast of the display substrate. The LTPS glass  244 , encapsulation glass  242  and polarizer  262  together form an AMOLED display. 
     As described above, the capacitive shielding  220  blocks capacitive signals that can impact a capacitance reading  238  between the sensing pad  230  and the reference ground layer  234 . As such, the sensing pad  230  can be positioned within an inactive area of the display or an active area. The pressure sensor  240  in this embodiment includes the sensing pads  230 , the reference ground layer  234 , the compression region  260  and the capacitive shielding  220 . 
       FIG. 3  shows another embodiment of a display device (or assembly)  300 . In this embodiment, capacitive shielding layer  310  is shown overlapping sensing pad traces  312  of a pressure sensor. A non-conductive layer  313  can be positioned between the capacitive shielding layer  310  and the sensing pad traces  312  so as to prevent current flow there between. In this embodiment, a reference ground layer  320 , which is part of the pressure sensor, is embedded between an encapsulation layer  322  and an LTPS layer  324 . Other types of display substrates can be used instead. A capacitance  330  can be formed between the sensing pad traces  312  and the reference ground layer  320 . The display device  300  illustrates that the reference ground layer  320  can be positioned at multiple different locations below a compression region  340 . The sensing pad traces  312  are above the compression region  340  and the sensing pad traces  312  have gaps  350  there between. The capacitive shielding layer  310  also has the gaps  350  between the traces so as to allow capacitive touch signals to pass through the capacitive shielding layer to the touch sensors.  FIG. 3  also illustrates that the capacitive shielding layer  310  can vary in width. For example, in an inactive region  360  the sensing pads  312  can be wider than in an active region  362 . Correspondingly, the capacitive shielding traces can be wider in the inactive region  360  so as to shield the sensing pads from capacitive touch signals. In any case, the sensing pads  312  of the pressure sensor can be in both the inactive region  360  and/or the active region  362 . The use of the capacitive shielding layer  310  makes any capacitance generated by a user&#39;s finger invisible to the pressure sensor. 
       FIG. 4  illustrates an embodiment for configuration of touch sensors  410 , sensing pads  420  and a capacitive shielding layer  430 . The touch sensors  410  can include a plurality of metal traces in a lattice pattern. The lattice pattern is formed by rows and columns, TX and RX traces in separate layers with a thin separation between the two layers. When a finger touches the window substrate, a mutual capacitance between the rows and columns is reduced. This reduction in capacitance can be used to identify the presence and location of a finger. Although this embodiment shows a mutual capacitance structure, other touch sensing structures can be used such as surface capacitance, projected capacitance, and self capacitance. 
     The sensing pads  420  are shown as being a plurality of traces  422  at an angle with respect to the edges  440  of the display. The sensing pads  420  are electrically coupled together, but have gaps  450  between the traces. The gaps  450  are sized such that capacitive signals from a finger touch can bypass the sensing pads  420  to reach the touch sensors  410 . A single output  460  from the sensing pads  420  can be sufficient to sense pressure. The capacitive shielding layer  430  can also have a plurality of traces  432  designed to overlay the traces of the sensing pads  420 . The traces of the capacitive shielding layer  430  are wider than those of the sensing pads  420  so as to ensure that the sensing pad traces are adequately shielded. Additionally, the traces  432  of the capacitive shielding layer  430  has gaps  434  there between. A combination of the layers is shown at  470  with the touch sensors  410  being below the sensing pads  420 , which are below the capacitive shielding layer  430 . The sensing pads  420  should be sufficiently transparent so that visibility of the display content is not disturbed. Additionally, disturbance of the touch functionality is minimized The narrow sensing pads  420  together with the capacitive shielding layer  430  accomplishes these goals. The angled traces of the sensing pads  420  and the capacitive shielding layer  430  assist in hiding the pattern on the window substrate so it is less visible to users. 
       FIG. 5  illustrates another embodiment of the sensing pads  510  and capacitive shielding layer  540 . In this embodiment, the sensing pad  510  has four electrically separate zones  512 A- 512 D. Each zone has a physical gap between it and the adjacent zones, as is shown generally at  522 . Each zone has a separate pressure sensing output shown by output wires  530 . The capacitive shielding layer  540  is shown as an electrically unitary layer with angled traces that overlap the traces of the sensing pad  510 . The capacitive shielding layer  540  need not have gaps  522  that are present in the sensing pad  510 . A single input  544  can supply ground or another voltage level to the capacitive shielding layer  540 . 
     An alternative capacitive shielding layer  560  can have gaps  562  that align with the gaps  522  in the sensing pad  510  so as to have electrically different sections of the capacitive shielding layer  560 . Different input voltages can be supplied to each section as shown at  566 , so that different shielding voltages can be applied to different sections of the display, based on the desired requirements. 
       FIG. 6  is a method of using a display including a pressure sensor. In process block  610 , a window layer is provided for receiving touch signals. The window layer is generally a cover glass upon which the user touches to provide user input. In process block  620 , a sensing pad is provided. The sensing pad can include multiple conductive traces with gaps between the traces. For example,  FIG. 4  shows a sensing pad having conductive traces  422  with gaps  450  there between. The thicknesses of the traces and gaps are sized so as to minimize interference with touch signals provided by user input. In process block  630 , a capacitive shielding layer is provided that has gaps therein to allow capacitive effects of touch signals to pass. For example, returning to  FIG. 4 , the capacitive shielding layer is shown with conductive traces  432  with gaps  434  there between so as to match the gaps in the sensing pads  420 . In process block  640 , touch sensors are provided, such as the touch sensors  410  of  FIG. 4 . In process block  650 , a compression region is provided between the encapsulation layer and the sensing pads. For example, in  FIG. 2 , a compression region is shown at  260  between the encapsulation layer  242  and the sensing pad  230 . In process block  660 , touch signals are received, such as from a user, and the capacitive effects of the touch signals are blocked from reaching the sensing pad using the capacitive shielding layer. For example,  FIG. 1  shows the capacitive touch signals  185  being blocked by the capacitive shielding layer  171 . This ensures that the sensing pad is not impacted by the capacitive effects of a user finger. 
       FIG. 7  depicts a generalized example of a suitable computing system  700  in which the described innovations may be implemented. The computing system  700  is not intended to suggest any limitation as to scope of use or functionality, as the innovations may be implemented in diverse general-purpose or special-purpose computing systems. 
     With reference to  FIG. 7 , the computing system  700  includes one or more processing units  710 ,  715  and memory  720 ,  725 . In  FIG. 7 , this basic configuration  730  is included within a dashed line. The processing units  710 ,  715  execute computer-executable instructions. A processing unit can be a general-purpose central processing unit (CPU), processor in an application-specific integrated circuit (ASIC), or any other type of processor. Such a processor can be used to read an output from the sensing pad, as was illustrated in  FIG. 1 . In a multi-processing system, multiple processing units execute computer-executable instructions to increase processing power. For example,  FIG. 7  shows a central processing unit  710  as well as a graphics processing unit or co-processing unit  715 . The tangible memory  720 ,  725  may be volatile memory (e.g., registers, cache, RAM), non-volatile memory (e.g., ROM, EEPROM, flash memory, etc.), or some combination of the two, accessible by the processing unit(s). The memory  720 ,  725  stores software  780  implementing one or more innovations described herein, in the form of computer-executable instructions suitable for execution by the processing unit(s). 
     A computing system may have additional features. For example, the computing system  700  includes storage  740 , one or more input devices  750 , one or more output devices  760 , and one or more communication connections  770 . An interconnection mechanism (not shown) such as a bus, controller, or network interconnects the components of the computing system  700 . Typically, operating system software (not shown) provides an operating environment for other software executing in the computing system  700 , and coordinates activities of the components of the computing system  700 . 
     The tangible storage  740  may be removable or non-removable, and includes magnetic disks, magnetic tapes or cassettes, CD-ROMs, DVDs, or any other medium which can be used to store information and which can be accessed within the computing system  700 . The storage  740  stores instructions for the software  780 . 
     The input device(s)  750  may be a touch input device such as a touch display, a keyboard, mouse, pen, or trackball, a voice input device, a scanning device, or another device that provides input to the computing system  700 . For video encoding, the input device(s)  750  may be a camera, video card, TV tuner card, or similar device that accepts video input in analog or digital form, or a CD-ROM or CD-RW that reads video samples into the computing system  700 . The output device(s)  760  may be a display, printer, speaker, CD-writer, or another device that provides output from the computing system  700 . 
     The communication connection(s)  770  enable communication over a communication medium to another computing entity. The communication medium conveys information such as computer-executable instructions, audio or video input or output, or other data in a modulated data signal. A modulated data signal is a signal that has one or more of its characteristics set or changed in such a manner as to encode information in the signal. By way of example, and not limitation, communication media can use an electrical, optical, RF, or other carrier. 
     The innovations can be described in the general context of computer-executable instructions, such as those included in program modules, being executed in a computing system on a target real or virtual processor. Generally, program modules include routines, programs, libraries, objects, classes, components, data structures, etc. that perform particular tasks or implement particular abstract data types. The functionality of the program modules may be combined or split between program modules as desired in various embodiments. Computer-executable instructions for program modules may be executed within a local or distributed computing system. 
     The terms “system” and “device” are used interchangeably herein. Unless the context clearly indicates otherwise, neither term implies any limitation on a type of computing system or computing device. In general, a computing system or computing device can be local or distributed, and can include any combination of special-purpose hardware and/or general-purpose hardware with software implementing the functionality described herein. 
     For the sake of presentation, the detailed description uses terms like “determine” and “use” to describe computer operations in a computing system. These terms are high-level abstractions for operations performed by a computer, and should not be confused with acts performed by a human being. The actual computer operations corresponding to these terms vary depending on implementation. 
     Although the operations of some of the disclosed methods are described in a particular, sequential order for convenient presentation, it should be understood that this manner of description encompasses rearrangement, unless a particular ordering is required by specific language set forth below. For example, operations described sequentially may in some cases be rearranged or performed concurrently. Moreover, for the sake of simplicity, the attached figures may not show the various ways in which the disclosed methods can be used in conjunction with other methods. 
     Any of the disclosed methods can be implemented as computer-executable instructions or a computer program product stored on one or more computer-readable storage media and executed on a computing device (e.g., any available computing device, including smart phones or other mobile devices that include computing hardware). Computer-readable storage media are any available tangible media that can be accessed within a computing environment (e.g., one or more optical media discs such as DVD or CD, volatile memory components (such as DRAM or SRAM), or nonvolatile memory components (such as flash memory or hard drives)). By way of example and with reference to  FIG. 7 , computer-readable storage media include memory  720  and  725 , and storage  740 . 
     Any of the computer-executable instructions for implementing the disclosed techniques as well as any data created and used during implementation of the disclosed embodiments can be stored on one or more computer-readable storage media. The computer-executable instructions can be part of, for example, a dedicated software application or a software application that is accessed or downloaded via a web browser or other software application (such as a remote computing application). Such software can be executed, for example, on a single local computer (e.g., any suitable commercially available computer) or in a network environment (e.g., via the Internet, a wide-area network, a local-area network, a client-server network (such as a cloud computing network), or other such network) using one or more network computers. 
     The disclosed methods, apparatus, and systems should not be construed as limiting in any way. Instead, the present disclosure is directed toward all novel and nonobvious features and aspects of the various disclosed embodiments, alone and in various combinations and sub combinations with one another. The disclosed methods, apparatus, and systems are not limited to any specific aspect or feature or combination thereof, nor do the disclosed embodiments require that any one or more specific advantages be present or problems be solved. 
     The technologies from any example can be combined with the technologies described in any one or more of the other examples. In view of the many possible embodiments to which the principles of the disclosed technology may be applied, it should be recognized that the illustrated embodiments are examples of the disclosed technology and should not be taken as a limitation on the scope of the disclosed technology. 
     The following paragraphs further describe embodiments of the display: 
     A. A display, comprising: 
     a window substrate having an inactive area and an active area; 
     a compression region below the window substrate, the compression region being compressible when force is applied to the window substrate; 
     touch sensors below the compression region in the active area of the window substrate; 
     a pressure sensor including a sensing pad positioned between the compressible region and the window substrate, the pressure sensor used to detect when the compression region has force applied thereon; and 
     a capacitive shielding layer between the sensing pad and the window substrate, the capacitive shielding for blocking capacitive effects of a user touch on the window substrate from the pressure sensor. 
     B. The display of paragraph A, wherein the capacitive shielding layer is formed from conductive material with gaps therein for allowing capacitive effects of the user touch to pass through to the touch sensors. 
     C. The display of any of paragraphs A-B, wherein the pressure sensor is partially in the active area of the window substrate and overlaps with the touch sensors. 
     D. The display of any of paragraphs A-C, wherein the sensing pad includes conductive traces of a first width and the capacitive shielding layer includes conductive traces of a second width, which is wider than the first width, and overlaps with the conductive traces of the sensing pad so as to shield the pressure sensor from the capacitive effects. 
     E. The display of paragraph D, wherein the window substrate includes first and second edges and wherein the conductive traces of the sensing pad are at an angle with respect to the first and second edges. 
     F. The display of paragraph D, wherein the conductive traces of the sensing pad are electrically divided into multiple areas and wherein the conductive traces of the capacitive shielding layer is electrically a single layer. 
     G. The display of any of paragraphs A-F, wherein the compression region is an adhesive, a polymer or a combination thereof. 
     H. The display of any of paragraphs A-G, wherein the window substrate is made of glass or plastic. 
     I. The display of any of paragraphs A-H, wherein the pressure sensor further includes a ground layer below the compression region which forms a capacitor with the sensing pad. 
     J. A display device including a pressure sensor, comprising: 
     a window substrate; 
     a sensing pad of the pressure sensor; 
     a capacitive shielding layer between the sensing pad and the window substrate; 
     a reference ground layer below the sensing pad; and 
     a compression region between the sensing pad and the reference ground layer. 
     K. The display device of paragraph J, wherein the capacitive shielding layer is a conductive layer having a voltage applied thereto or ground applied thereto. 
     L. The display device of any of paragraphs J-K, further including touch sensors below the capacitive shielding layer, wherein the capacitive shielding layer has gaps therein to allow capacitive touch signals to pass through the capacitive shielding layer to the touch sensors. 
     M. The display device of any of paragraphs J-L, wherein the sensing pad includes multiple conductive traces in parallel having a first width and the capacitive shielding layer includes multiple conductive traces in parallel having a second width, wider than the first width, wherein the multiple conductive traces of the capacitive shielding layer cover the multiple conductive traces of the sensing pad. 
     N. The display device of paragraph M, wherein the multiple conductive traces of the sensing pad are electrically divided into multiple zones having separate electrical outputs. 
     O. The display device of any of paragraphs J-N, wherein the window substrate includes an active area, and an inactive area, and wherein the sensing pad is at least partially within the active area. 
     P. The display device of any of paragraphs J-O, wherein the compression region is a compressible adhesive. 
     Q. The display device of any of paragraphs J-P, further including an encapsulation layer below the reference ground layer and further including touch sensors on the encapsulation layer. 
     R. A method of using a display including a pressure sensor, comprising: 
     providing a window layer for receiving user touch signals; 
     providing a sensing pad of a pressure sensor between the window layer and an encapsulation layer, the sensing pad including multiple conductive traces with gaps between the traces; 
     providing a capacitive shielding layer between the sensing pad and the window layer to shield the sensing pad from the touch signals, wherein the capacitive shielding layer has gaps therein to allow capacitive effects of the touch signals to pass through the capacitive shielding layer; 
     providing touch sensors above the encapsulation layer; 
     providing a compression region between the encapsulation layer and the sensing pad; and 
     receiving touch signals on the window layer, and blocking capacitive effects of the touch signals from the sensing pad using the capacitive shielding layer, and allowing the capacitive effects to pass to the touch sensors through the gaps in the capacitive shielding layer. 
     S. The method of paragraph R, further including receiving a pressure on the window layer that compresses the compression region; and 
     sensing a change in capacitance using the sensing pad due to a change in distance between the sensing pad and a reference ground layer on an opposite side of the compression region from the sensing pad. 
     T. The method of any of paragraphs R-S, wherein the capacitive shielding layer comprises multiple traces at an angle with respect to an edge of the window layer. 
     In view of the many possible embodiments to which the principles of the disclosed invention may be applied, it should be recognized that the illustrated embodiments are only preferred examples of the invention and should not be taken as limiting the scope of the invention. Rather, the scope of the invention is defined by the following claims. We therefore claim as our invention all that comes within the scope of these claims.