PATENT DOCUMENT

Publication Number: US-11733801-B2
Application Number: US-201816146675-A
Country: US
Kind Code: B2

Title: Touch sensor panel architecture with multiple sensing mode capabilities

Abstract:
A touch sensor panel is disclosed. The touch sensor panel includes a first layer including a plurality of electrodes of a first type that are coupled to respective traces and are configured to operate as touch sensing electrodes during a first time period. The touch sensor panel also includes a second layer including a plurality of electrodes of a second type overlapping with the respective traces of the electrodes of the first type. The electrodes of the second type are configured to operate as guard electrodes for the respective traces of the electrodes of the first type during the first time period and operate as touch sensing electrodes during a second time period.

Claims:
The invention claimed is: 
     
       1. A touch sensor panel comprising:
 a first layer including a plurality of electrodes of a first type, wherein the electrodes of the first type are coupled to respective traces, and the electrodes of the first type are configured to, during a first time period and a second time period, operate as touch sensing electrodes; and 
 a second layer including a plurality of electrodes of a second type overlapping with the respective traces of the electrodes of the first type, wherein the electrodes of the second type are configured to:
 during the first time period, operate as guard electrodes for the respective traces of the electrodes of the first type; and 
 during the second time period, be coupled to sensing circuitry and operate as electrodes that are sensed for touch via the sensing circuitry. 
 
 
     
     
       2. The touch sensor panel of  claim 1 , wherein the first type of electrodes are a different type of electrode than the second type of electrodes. 
     
     
       3. The touch sensor panel of  claim 2 , wherein:
 the first type of electrodes are touch node electrodes; and 
 the second type of electrodes are elongated electrodes. 
 
     
     
       4. The touch sensor panel of  claim 1 , wherein operating, during the first time period, the electrodes of the second type as the guard electrodes comprises driving the electrodes of the second type at a reference voltage. 
     
     
       5. The touch sensor panel of  claim 1 , wherein operating, the electrodes of the first type as the touch sensing electrodes comprises operating the electrodes of the first type as self-capacitance sensing electrodes. 
     
     
       6. The touch sensor panel of  claim 1 , wherein operating the electrodes of the second type as electrodes that are sensed for touch comprises operating the electrodes of the second type as mutual capacitance electrodes. 
     
     
       7. The touch sensor panel of  claim 1 , further comprising:
 a third layer including an electrode of a third type configured to, during the first and second time periods, operate as a guard electrode. 
 
     
     
       8. The touch sensor panel of  claim 7 , wherein the electrode of the third type is further configured to:
 during a third time period, operate as a force sensing electrode. 
 
     
     
       9. The touch sensor panel of  claim 8 , wherein the first type of electrodes are further configured to:
 during the third time period, operate as force sensing electrodes, wherein during the third time period, a force is determined based on the electrode of the third type and the electrodes of the first type. 
 
     
     
       10. The touch sensor panel of  claim 8 , wherein the second type of electrodes are further configured to:
 during the third time period, operate as force sensing electrodes, wherein during the third time period, a force is determined based on the electrode of the third type and the electrodes of the second type. 
 
     
     
       11. The touch sensor panel of  claim 1 , further comprising:
 a third layer including a plurality of electrodes of a third type, wherein the electrodes of the third type are configured to:
 during the first time period, operate as guard electrodes for the respective traces of the electrodes of the first type; and 
 during the second time period, be coupled to sensing circuitry and operate as electrodes that are sensed for touch via the sensing circuitry. 
 
 
     
     
       12. The touch sensor panel of  claim 11 , wherein:
 the first type of electrodes are touch node electrodes; and 
 the second and third types of electrodes are elongated electrodes. 
 
     
     
       13. The touch sensor panel of  claim 11 , wherein:
 operating, during the first time period, the electrodes of the second and third types as the guard electrodes comprises driving the electrodes of the second and third types at a reference voltage. 
 
     
     
       14. The touch sensor panel of  claim 11 , wherein operating, during the first time period, the electrodes of the first type as the touch sensing electrodes comprises operating the electrodes of the first type as self-capacitance sensing electrodes. 
     
     
       15. The touch sensor panel of  claim 11 , wherein:
 operating, during the second time period, the electrodes of the second type as electrodes that are sensed for touch comprises operating the electrodes of the second type as mutual capacitance electrodes with respect to the electrodes of the third type; and 
 operating, during the second time period, the electrodes of the third type as the touch sensing electrodes comprises operating the electrodes of the third type as mutual capacitance electrodes with respect to the electrodes of the second type. 
 
     
     
       16. The touch sensor panel of  claim 15 , wherein operating, during the first time period, the electrodes of the first type as the touch sensing electrodes comprises operating the electrodes of the first type as self-capacitance sensing electrodes. 
     
     
       17. The touch sensor panel of  claim 11 , wherein the electrodes of the first type are further configured to:
 during a third time period, operate as mutual capacitance electrodes. 
 
     
     
       18. The touch sensor panel of  claim 17 , wherein the electrodes of the second type are further configured to:
 during the third time period, operate as mutual capacitance electrodes with respect to the electrodes of the first type. 
 
     
     
       19. The touch sensor panel of  claim 17 , wherein the electrodes of the third type are further configured to:
 during the third time period, operate as mutual capacitance electrodes with respect to the electrodes of the first type. 
 
     
     
       20. The touch sensor panel of  claim 17 , further comprising:
 a fourth layer including an electrode of a fourth type configured to, during the first, second, and third time periods, operate as a guard electrode. 
 
     
     
       21. The touch sensor panel of  claim 20 , wherein the electrode of the fourth type is further configured to:
 during a fourth time period, operate as a force sensing electrode. 
 
     
     
       22. The touch sensor panel of  claim 21 , wherein operating the electrodes of the first type as mutual capacitance electrodes comprises operating the electrodes of the first type as force sensing electrodes, wherein during the fourth time period, a force is determined based on the electrode of the fourth type and the electrodes of the first type. 
     
     
       23. The touch sensor panel of  claim 11 , wherein operating the electrodes of the second type as electrodes that are sensed for touch comprises operating the electrodes of the second type as mutual capacitance electrodes with respect to the electrodes of the third type; and
 operating the electrodes of the third type as the touch sensing electrodes comprises operating the electrodes of the third type as mutual capacitance electrodes with respect to the electrodes of the second type. 
 
     
     
       24. The touch sensor panel of  claim 1 , wherein:
 the plurality of electrodes of the second type are arranged in rows along a horizontal axis, and include extensions along a vertical axis that overlap with the respective traces of the electrodes of the first type. 
 
     
     
       25. The touch sensor panel of  claim 1 , wherein operating the electrodes of the second type as electrodes that sense touch comprises operating the electrodes of the second type as self-capacitance electrodes. 
     
     
       26. A touch sensor panel comprising:
 a first layer including a plurality of electrodes of a first type, wherein the electrodes of the first type are configured to, during a first time period, operate as mutual capacitance drive electrodes; and 
 a second layer including a plurality of electrodes of a second type overlapping with the electrodes of the first type, wherein the plurality of electrodes of the second type are arranged in a plurality of rows and columns, and a respective row or column of the plurality of rows and columns in the second layer includes at least a first electrode and a second electrode of the second type, and the first electrode and second electrode are configured to:
 during the first time period, operate as a combined mutual capacitance sense electrode comprising the first electrode and the second electrode that are sensed by a same sensing circuitry; and 
 during a second time period, operate as self-capacitance electrodes that are sensed individually by different sense circuitry. 
 
 
     
     
       27. The touch sensor panel of  claim 26 , wherein:
 during the first time period, the plurality of electrodes of the second type in the respective row or column are sensed with the same sense circuitry. 
 
     
     
       28. The touch sensor panel of  claim 27 , wherein:
 the plurality of electrodes of the first type are arranged in columns along a vertical axis, 
 a given column of electrodes of the first type includes a plurality of individually addressable electrodes of the first type, and 
 during the first time period, the plurality of individually addressable electrodes of the first type in the given column are driven with a same drive signal. 
 
     
     
       29. The touch sensor panel of  claim 28 , wherein the plurality of electrodes of the first type and the plurality of electrodes of the second type are grouped to form a plurality of super nodes on the touch sensor panel, and each super node is individually operable to perform independent touch sensing operations. 
     
     
       30. The touch sensor panel of  claim 26 , wherein the plurality of electrodes of the first type operate as self-capacitance electrodes that are sensed for touch during the second time period. 
     
     
       31. A method for operating a touch sensor panel, the method comprising:
 operating a plurality of electrodes of a first type, during a first time period and a second time period, as touch sensing electrodes, wherein the electrodes of the first type are in a first layer of the touch sensor panel and are coupled to respective traces; and 
 operating a plurality of electrodes of a second type:
 during the first time period, as guard electrodes for the respective traces of the electrodes of the first type; and 
 during the second time period, as electrodes that are sensed for touch via sensing circuitry coupled to the plurality of electrodes of the second type, 
 
 wherein the electrodes of the second type are in a second layer of the touch sensor panel and overlap with the respective traces of the electrodes of the first type. 
 
     
     
       32. A non-transitory computer readable storage medium storing one or more programs, the one or more programs comprising instructions, which when executed by a processor, cause the processor to perform a method for operating a touch sensor panel comprising:
 operating a plurality of electrodes of a first type, during a first time period and a second time period, as touch sensing electrodes, wherein the electrodes of the first type are in a first layer of the touch sensor panel and are coupled to respective traces; and 
 operating a plurality of electrodes of a second type:
 during the first time period, as guard electrodes for the respective traces of the electrodes of the first type; and 
 during the second time period, as electrodes that are sensed for touch via sensing circuitry coupled to the plurality of electrodes of the second type, 
 
 wherein the electrodes of the second type are in a second layer of the touch sensor panel and overlap with the respective traces of the electrodes of the first type.

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
     This application claims benefit of U.S. Provisional Patent Application No. 62/566,092, filed Sep. 29, 2017, which is hereby incorporated by reference in its entirety. 
    
    
     FIELD OF THE DISCLOSURE 
     This relates generally to touch sensor panels, and more particularly to touch sensor panels with multiple sensing mode capabilities. 
     BACKGROUND OF THE DISCLOSURE 
     Many types of input devices are presently available for performing operations in a computing system, such as buttons or keys, mice, trackballs, joysticks, touch sensor panels, touch screens and the like. Touch screens, in particular, are popular because of their ease and versatility of operation as well as their declining price. Touch screens can include a touch sensor panel, which can be a clear panel with a touch-sensitive surface, and a display device such as a liquid crystal display (LCD), light emitting diode (LED) display or organic light emitting diode (OLED) display that can be positioned partially or fully behind the panel so that the touch-sensitive surface can cover at least a portion of the viewable area of the display device. Touch screens can allow a user to perform various functions by touching the touch sensor panel using a finger, stylus or other object at a location often dictated by a user interface (UI) being displayed by the display device. In general, touch screens can recognize a touch and the position of the touch on the touch sensor panel, and the computing system can then interpret the touch in accordance with the display appearing at the time of the touch, and thereafter can perform one or more actions based on the touch. In the case of some touch sensing systems, a physical touch on the display is not needed to detect a touch. For example, in some capacitive-type touch sensing systems, fringing electrical fields used to detect touch can extend beyond the surface of the display, and objects approaching near the surface may be detected near the surface without actually touching the surface. 
     Capacitive touch sensor panels can be formed by substantially transparent or non-transparent conductive plates (e.g., touch electrodes) made of materials such as Indium Tin Oxide (ITO). In some examples, the conductive plates can be formed from other materials including conductive polymers, metal mesh, graphene, nanowires (e.g., silver nanowires) or nanotubes (e.g., carbon nanotubes). It is due in part to their substantial transparency that some capacitive touch sensor panels can be overlaid on a display to form a touch screen, as described above. Some touch screens can be formed by at least partially integrating touch sensing circuitry into a display pixel stackup (i.e., the stacked material layers forming the display pixels). 
     SUMMARY OF THE DISCLOSURE 
     There are many types of sensing that can be performed on a touch sensor panel. In some examples, touch sensor panels can perform hover, touch, force, and/or stylus sensing. These different types of sensing capabilities can be performed using various touch electrode configurations for mutual capacitance and/or self-capacitance sensing. Further, touch sensing performance of touch sensor panels may benefit from having various guard/shield elements in the touch sensor panels that help shield certain touch sensing circuitry (e.g., touch electrodes) from noise sources that can otherwise inject noise into touch sensing signals. Having dedicated circuitry (e.g., electrodes) for each of these sensing and/or guarding capabilities can result in complex, expensive, and/or thick touch sensor panels. The examples of the disclosure provide various touch sensing system configurations that can operate the same touch circuitry (e.g., electrodes) in different modes to perform hover, touch, force, and/or stylus sensing and/or guarding functions. Doing so can help improve and/or provide hover, touch, and/or force sensing capabilities to the system while reducing the number of electrodes and corresponding routing traces. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIGS.  1 A- 1 D  illustrate example systems in which a touch screen according to examples of the disclosure may be implemented. 
         FIG.  2    is a block diagram of an example computing system that illustrates one implementation of an example touch screen according to examples of the disclosure. 
         FIG.  3    illustrates an exemplary touch sensor circuit for performing a self-capacitance measurement using an electrode and sensing circuit according to examples of the disclosure. 
         FIG.  4    illustrates an exemplary touch sensor circuit for performing a mutual capacitance measurement using two electrodes and sensing circuit according to examples of the disclosure. 
         FIGS.  5 A- 5 D  illustrate exemplary touch sensor panel configurations with three layers of electrodes according to examples of the disclosure. 
         FIGS.  5 E- 5 I  illustrate exemplary tables describing different modes of operation for exemplary touch sensor panel configurations with three layers of electrodes according to examples of the disclosure. 
         FIGS.  5 J- 5 M  illustrate additional exemplary touch sensor panel configurations according to examples of the disclosure. 
         FIGS.  6 A- 6 D  illustrate exemplary touch sensor panel configurations with four layers of electrodes according to examples of the disclosure. 
         FIGS.  6 E- 6 K  illustrate exemplary tables describing different modes of operation for exemplary touch sensor panel configurations with four layers of electrodes according to examples of the disclosure. 
         FIG.  7    illustrates an exemplary touch sensor panel configuration with four layers of electrodes according to examples of the disclosure. 
         FIG.  8    illustrates an exemplary timeline  800  of the modes of operation for exemplary touch sensor panel configurations according to examples of the disclosure. 
         FIG.  9 A  illustrates another exemplary timeline of the modes of operation for exemplary touch sensor panel configurations according to examples of the disclosure. 
         FIG.  9 B  illustrates an exemplary process for switching between modes of operation of exemplary touch sensor panel configurations according to examples of the disclosure. 
         FIG.  10    illustrates an exemplary timeline of the modes of operation for exemplary touch sensor panel configurations according to examples of the disclosure. 
         FIG.  11    illustrates a touch sensor panel. 
     
    
    
     DETAILED DESCRIPTION 
     In the following description of examples, reference is made to the accompanying drawings which form a part hereof, and in which it is shown by way of illustration specific examples that can be practiced. It is to be understood that other examples can be used and structural changes can be made without departing from the scope of the disclosed examples. 
     Generally, touch sensor panels comprise a plurality of plates formed from a conductive material; these plates are referred to herein as “touch electrodes.” The touch electrodes may be made from any suitable conductive material (e.g., a transparent conductive oxide such as ITO or aluminum zinc oxide, a metal such as copper, a metal mesh material comprising a conductive cross-hatched metal structure with gaps between cross-hatched metal lines, carbon nanotube material, or any other suitable conductive material) which may be substantially transparent or non-transparent, depending on the application. In some instances where the touch electrodes are substantially transparent, the touch sensor panel may be placed on or otherwise integrated into a display (e.g., the touch electrodes may be placed within the display stack and/or may be utilized during the operation of the display to provide display functionality) to provide a touch sensitive display. 
     During operation of the touch sensor panels described here, a given touch electrode or plurality of electrodes may be configured to perform mutual capacitance touch sensing or a self-capacitance touch sensing. It should be appreciated that a given electrode may be used to perform mutual capacitance touch sensing at one point in time and self-capacitance touch sensing at a different point in time (e.g., by reconfiguring the touch sensor circuitry used to operate the touch electrode, or connecting the touch electrode to different touch sensor circuitry), but some of the touch electrodes may be dedicated to mutual capacitance sensing where a given touch electrode can be stimulated with an AC waveform (e.g., the “drive electrode”) and the mutual capacitance between that electrode and another touch electrode can be sensed at the other electrode (e.g., the “sense electrode”). To facilitate mutual capacitance sensing, a touch sensor panel may have touch electrodes arranged in rows and columns where a mutual capacitance may be measured at an overlap or adjacency of a row and a column. In these instances it may be desirable for the rows and columns to have a relatively high aspect ratio (e.g., elongated electrodes with relatively high aspect ratio 1:x where 1 represents a height or width of the electrode and x represents the other of the height or width of the electrode, e.g., where x is greater than 4, 5, 10, 15, 20, etc.), and in some instances a row or column may span a relatively large portion of the touch sensor panel (e.g., at least a quarter of the panel, at least half of the panel, or at least three quarters of the panel). Mutual capacitance sensing can determine the location of a touch on the touch sensor panel with relatively high precision, but may have trouble detecting objects (e.g., fingers) further away from the touch sensor panel (e.g., hovering over the touch sensor panel). 
     Conversely, the self-capacitance of a given touch electrode can be sensed by stimulating the touch electrode with an AC waveform, and measuring the self-capacitance to ground of that same touch electrode. When one or more electrodes of a touch sensor panel are operated in a self-capacitance sensing mode, the electrodes can effectively detect the locations of one or more objects (e.g., fingers) hovering over and/or touching the touch sensor panels, but may be susceptible to noise and jitter that can introduce errors and/or offsets into the touch outputs of the touch sensor panels. Generally, touch panels optimized for self-capacitance utilize a matrix architecture in which electrodes are arranged in a two-dimensional array to form rows and columns, each row and column comprising a respective plurality of electrodes. The individual electrodes are approximately the same size (although it should be appreciated that some electrodes may be larger or smaller to accommodate routing traces or to balance the bandwidth of individual electrodes). Generally it is desirable for the self-capacitance electrodes to have a relatively low aspect ratio (e.g., relatively low aspect ratio 1:x as discussed above, where x is less than or equal to 4, 5, 10, 15, 20, and preferably less than or equal to 1.5). Depending on the size of the panel and the pitch/size of individual electrodes, a matrix architecture of self-capacitance touch node electrodes can require a large number of self-capacitance touch electrodes and corresponding routing traces. Therefore, it can be beneficial to combine touch electrodes that are operated to sense mutual capacitance and self-capacitance in a single touch sensor panel. The examples of the disclosure provide various touch sensing system configurations that can operate the same touch circuitry (e.g., electrodes) in different modes to perform hover, touch, force, and/or stylus sensing and/or guarding functions. Doing so can help improve and/or provide hover, touch, and/or force sensing capabilities to the system while reducing the number of electrodes and corresponding routing traces. 
       FIGS.  1 A- 1 D  illustrate example systems in which a touch screen according to examples of the disclosure may be implemented.  FIG.  1 A  illustrates an example mobile telephone  136  that includes a touch screen  124 .  FIG.  1 B  illustrates an example digital media player  140  that includes a touch screen  126 .  FIG.  1 C  illustrates an example personal computer  144  that includes a touch screen  128 .  FIG.  1 D  illustrates an example tablet computer  148  that includes a touch screen  130 . It is understood that the above touch screens can be implemented in other devices as well, including in wearable devices. 
     In some examples, touch screens  124 ,  126 ,  128  and  130  can be configured and optimized to operate using a combination of self-capacitance and mutual capacitance sensing. For example, a self-capacitance mode can be used for touch and/or hover sensing, and a mutual capacitance mode can be used for touch and/or force sensing. A self-capacitance and mutual capacitance hybrid touch system can include a matrix of small, individual plates of conductive material that can be referred to as touch node electrodes (e.g., electrodes with relatively low aspect ratio, as described above) for performing self-capacitance touch measurements in a self-capacitance mode and mutual capacitance touch measurements in a mutual capacitance mode. The touch screen system can also include a plurality of elongated electrodes in a row/column configuration (e.g., electrodes with relatively high aspect ratio) on a different layer that can be operated as an active guard (e.g., to shield the traces of the touch node electrodes), can be used to perform self-capacitance touch measurements during the self-capacitance mode and can be operated as sense and/or drive electrodes during the mutual capacitance mode. The plurality of elongated electrodes may all be on the same layer and be placed along the same direction (e.g., in a row/column configuration) or may be placed on two different layers with a first set of elongated electrodes in a first layer in a first direction (e.g., in a row configuration) and a second set of elongated electrodes on a second layer in a second direction, different than the first layer and the first direction (e.g., in a column configuration) such that the elongated electrodes may cross over each other on different layers (as described below with reference to touch screen  220  in  FIG.  2   ). When the electrodes are operated as drive electrodes and sense electrodes, the crossings (e.g., when the elongated electrodes are on two different layers) or adjacent locations (e.g., when the elongated electrodes are on one layer) of the elongated electrodes can be referred to as mutual capacitance touch nodes. When the electrodes are used to perform self-capacitance touch measurements, the electrodes can be referred to as self-capacitance touch node electrodes. Self-capacitance touch node electrodes and mutual capacitance touch nodes are discussed in turn. 
     A self-capacitance and mutual capacitance hybrid touch screen can include a plurality of individual touch node electrodes, each touch node electrode identifying or representing a unique location on the touch screen at which touch or proximity (i.e., a touch or proximity event) is to be sensed and each touch node electrode being electrically isolated from the other touch node electrodes in the touch screen/panel. The touch node electrodes can be on the same or different material layers on touch sensor panel. It is understood that in some examples the touch node electrodes on the touch screen can be operated in a self-capacitance sensing mode in which their self-capacitance is sensed, and in some examples can be used to perform scans other than self-capacitance scans on the touch screen (e.g., mutual capacitance scans in combination with or instead of mutual capacitance scans of the row and column electrodes). During self-capacitance operation, a touch node electrode can be stimulated with an AC waveform, and the self-capacitance to ground of the touch node electrode can be measured. As an object approaches the touch node electrode, the self-capacitance to ground of the electrode can change. This change in the self-capacitance of the touch node electrode can be detected and measured by the touch sensing system to determine the positions of multiple objects (e.g., styli and/or fingers) when they touch, or come in proximity to, the touch screen. In some examples, a touch screen can be multi-touch, single touch, projection scan, full-imaging multi-touch, capacitive touch, etc. 
     As discussed above, a self-capacitance and mutual capacitance hybrid touch screen can also include a plurality of row electrodes (e.g., elongated electrodes disposed as rows) and a plurality of column electrodes (e.g., elongated electrodes disposed as columns). In some examples, the row electrodes can be configured as drive electrodes, and the column electrodes can be configured as sense electrodes (or vice versa), which can form mutual capacitance touch nodes at the intersections (or adjacent locations) of the drive and sense electrodes. In some examples, touch node electrodes with a relatively low aspect ratio can be grouped in columns or rows and be operated as sense and/or drive electrodes. The drive and sense electrodes can be on the same or different material layers on the touch screen. In some examples, the drive circuitry used to drive the drive electrodes and the sense circuitry used to sense the sense electrodes can be fixed, or can be variable such that the drive and sense designations of the row and column electrodes, respectively, can be switched during touch screen operation (e.g., the row electrodes can become sense electrodes, and the column electrodes can become drive electrodes). It is understood that the row and column designations of the above electrodes is not necessarily tied to any specific orientation of the device with which the touch screen is integrated, and that such designation can be relative to any suitable reference point. 
     During operation, the drive electrodes can be stimulated with an AC waveform (e.g., the same or different AC waveform that stimulates the touch node electrodes described previously in the self-capacitance configuration), and the mutual capacitance of the mutual capacitance touch nodes can be measured via the sense electrodes. As an object approaches the touch node, the mutual capacitance of the mutual capacitance touch node can change. This change in the mutual capacitance of the touch node can be detected and measured by the touch sensing system to determine the positions of multiple objects when they touch, or come in proximity to, the touch screen. It is understood that, in some examples, the row and column electrodes on the touch screen can be used to perform scans other than mutual capacitance scans of the touch screen (e.g., self-capacitance scans in combination with or instead of the touch node electrodes described previously). 
       FIG.  2    is a block diagram of an example computing system  200  that illustrates one implementation of an example self-capacitance and mutual capacitance hybrid touch screen  220  according to examples of the disclosure. Computing system  200  can be included in, for example, mobile telephone  136 , digital media player  140 , personal computer  144 , tablet computer  148 , or any mobile or non-mobile computing device that includes a touch screen, including a wearable device. Computing system  200  can include a touch sensing system including one or more touch processors  202 , peripherals  204 , a touch controller  206 , and touch driving and/or sensing circuitry (described in more detail below). Peripherals  204  can include, but are not limited to, random access memory (RAM) or other types of memory or storage, watchdog timers and the like. Touch controller  206  can include, but is not limited to, one or more drive/sense channels  208  and channel scan logic  210 . Channel scan logic  210  can access RAM  212 , autonomously read data from drive/sense channels  208  and provide control for the drive/sense channels. In addition, channel scan logic  210  can control drive/sense channels  208  to generate stimulation signals at various frequencies and phases that can be selectively applied to the touch node electrodes and/or row and column electrodes of touch screen  220 , as described in more detail below. In some examples, touch controller  206 , touch processor  202  and peripherals  204  can be integrated into a single application-specific integrated circuit (ASIC), and in some examples can be integrated with touch screen  220  itself. 
     Touch screen  220  can include touch sensing circuitry that can include a capacitive sensing medium having a plurality of electrically isolated touch node electrodes  222  and a plurality of column electrodes  223  and a plurality of row electrodes  224  (e.g., a plurality of elongated touch electrodes disposed as rows and a plurality of elongated electrodes disposed as columns, respectively). Touch node electrodes  222 , column electrodes  223 , and row electrodes  224  can each be on a different layer (e.g., touch node electrodes in a first layer, column electrodes  223  on a second layer, and row electrodes  224  on a third layer, wherein the first, second, and third layers are different). In a mutual capacitance configuration, the intersection of column electrodes  223  and row electrodes  224  can form mutual capacitance touch nodes  226 , as discussed above. In a self-capacitance mode, touch node electrodes  222  can be coupled to drive/sense channels  208  in touch controller  206 , can be driven by stimulation signals from the drive/sense channels through drive/sense interface  225 , and can be sensed for self-capacitance by the sense channels through the drive/sense interface as well, as described above. In a mutual capacitance mode, touch node electrodes  222  can be coupled to drive channels or sense channels  208  in touch controller  206  and can be driven by stimulation signals from the drive channels through drive/sense interface  225  (if coupled to drive channels), and can be sensed by the sense channels through the drive/sense interface as well (if coupled to sense channels), as described above. Additionally or alternatively in the mutual capacitance mode, column electrodes  223  can be coupled to drive channels  208  in touch controller  206 , can be driven by stimulation signals from the drive channels through drive/sense interface  225 , and row electrodes  224  can be sensed by the sense channels through the drive/sense interface as well, as described above. Labeling the locations used to detect touch (i.e., touch node electrodes  222  and mutual capacitance touch nodes  226 ) as “touch nodes” (or “touch node” electrodes) can be particularly useful when touch screen  220  is viewed as capturing an “image” of touch (e.g., a “touch image”). In other words, after touch controller  206  has determined an amount of touch detected at each touch node electrode  222  and/or mutual capacitance touch node  226  in touch screen  220 , the pattern of touch nodes or touch node electrodes in the touch screen at which a touch occurred can be thought of as a touch image (e.g., a pattern of fingers touching the touch screen). 
     Computing system  200  can also include a host processor  228  for receiving outputs from touch processor  202  and performing actions based on the outputs. For example, host processor  228  can be connected to program storage  232  and a display controller, such as a display driver  234  (e.g., for controlling operation of a display, such as an LCD display, on OLED display, etc.). The display driver  234  can provide voltages on select (e.g., gate) lines to each pixel transistor and can provide data signals along data lines to these same transistors to control the pixel display image as described in more detail below. Host processor  228  can use display driver  234  to generate a display image on touch screen  220 , such as a display image of a user interface (UI), and can use touch processor  202  and touch controller  206  to detect a touch on or near touch screen  220 . The touch input can be used by computer programs stored in program storage  232  to perform actions that can include, but are not limited to, moving an object such as a cursor or pointer, scrolling or panning, adjusting control settings, opening a file or document, viewing a menu, making a selection, executing instructions, operating a peripheral device connected to the host device, answering a telephone call, placing a telephone call, terminating a telephone call, changing the volume or audio settings, storing information related to telephone communications such as addresses, frequently dialed numbers, received calls, missed calls, logging onto a computer or a computer network, permitting authorized individuals access to restricted areas of the computer or computer network, loading a user profile associated with a user&#39;s preferred arrangement of the computer desktop, permitting access to web content, launching a particular program, encrypting or decoding a message, and/or the like. Host processor  228  can also perform additional functions that may not be related to touch processing. 
     Note that one or more of the functions described herein, including the configuration of switches, can be performed by firmware stored in memory (e.g., one of the peripherals  204  in  FIG.  2   ) and executed by touch processor  202 , or stored in program storage  232  and executed by host processor  228 . The firmware can also be stored and/or transported within any non-transitory computer-readable storage medium for use by or in connection with an instruction execution system, apparatus, or device, such as a computer-based system, processor-containing system, or other system that can fetch the instructions from the instruction execution system, apparatus, or device and execute the instructions. In the context of this document, a “non-transitory computer-readable storage medium” can be any medium (excluding signals) that can contain or store the program for use by or in connection with the instruction execution system, apparatus, or device. The computer-readable storage medium can include, but is not limited to, an electronic, magnetic, optical, electromagnetic, infrared, or semiconductor system, apparatus or device, a portable computer diskette (magnetic), a random access memory (RAM) (magnetic), a read-only memory (ROM) (magnetic), an erasable programmable read-only memory (EPROM) (magnetic), a portable optical disc such a CD, CD-R, CD-RW, DVD, DVD-R, or DVD-RW, or flash memory such as compact flash cards, secured digital cards, USB memory devices, memory sticks, and the like. 
     The firmware can also be propagated within any transport medium for use by or in connection with an instruction execution system, apparatus, or device, such as a computer-based system, processor-containing system, or other system that can fetch the instructions from the instruction execution system, apparatus, or device and execute the instructions. In the context of this document, a “transport medium” can be any medium that can communicate, propagate or transport the program for use by or in connection with the instruction execution system, apparatus, or device. The transport medium can include, but is not limited to, an electronic, magnetic, optical, electromagnetic or infrared wired or wireless propagation medium. 
       FIG.  3    illustrates an exemplary touch sensor circuit  300  for performing a self-capacitance measurement using an electrode (e.g., a touch node electrode  302 ) and sensing circuit  314  according to examples of the disclosure. Sensing circuit  314  can be included in sense channels  208  to sense the self-capacitance of one or more touch electrodes on the touch sensor panels/touch screens of the disclosure. Touch node electrode  302  can correspond to a touch node electrode  222 , a column electrode  223 , or a row electrode  224  when operated in a self-capacitance mode. Touch node electrode  302  can have an inherent self-capacitance to ground associated with it, and also an additional self-capacitance to ground that is formed when an object, such as finger  305 , is in proximity to or touching the electrode. The total self-capacitance to ground of touch node electrode  302  can be illustrated as capacitance  304 . Touch node electrode  302  can be coupled to sensing circuit  314 . Sensing circuit  314  can include an operational amplifier  308 , feedback resistor  312  and feedback capacitor  310 , although other configurations can be employed. For example, feedback resistor  312  can be replaced by a switched capacitor resistor in order to minimize a parasitic capacitance effect that can be caused by a variable feedback resistor. Touch node electrode  302  can be coupled to the inverting input (−) of operational amplifier  308 . An AC voltage source  306  (Vac) can be coupled to the non-inverting input (+) of operational amplifier  308 . Touch sensor circuit  300  can be configured to sense changes in the total self-capacitance  304  of the touch node electrode  302  induced by a finger or object either touching or in proximity to the touch sensor panel. Output  320  can be used by a processor to determine the presence of a proximity or touch event, or the output can be inputted into a discrete logic network to determine the presence of a proximity or touch event. 
       FIG.  4    illustrates an exemplary touch sensor circuit  450  for performing a mutual capacitance measurement using two electrodes (a drive electrode  422  and sense electrode  426 , such as the column electrodes and row electrodes described previously) and sensing circuit  414  according to examples of the disclosure. Stimulation signal  406  can be generated by drive channels  208  (e.g., drive channels  208  can include an AC stimulation source  406 ), drive electrode  422  can correspond to column electrode  223 , sense electrode  426  can correspond to row electrode  224 , and sensing circuit  414  can be included in sense channels  208 . Drive electrode  422  can be stimulated by stimulation signal  406  (e.g., an AC voltage signal). Stimulation signal  406  can be capacitively coupled to sense electrode  426  through mutual capacitance  424  between drive electrode  422  and sense electrode  426 . When a finger or object  405  approaches the touch node created by the intersection of drive electrode  422  and sense electrode  426 , mutual capacitance  424  can be altered. The intersection of drive electrode  422  and sense electrode  426  can correspond to a mutual capacitance touch node  226 . This change in mutual capacitance  424  can be detected to indicate a touch or proximity event at the touch node, as described previously and below. The sense signal coupled onto sense electrode  426  can be received by sensing circuit  414 . Sensing circuit  414  can include operational amplifier  408  and at least one of a feedback resistor  412  and a feedback capacitor  410 .  FIG.  4    illustrates a general case in which both resistive and capacitive feedback elements are utilized. The sense signal (referred to as Vin) can be inputted into the inverting input of operational amplifier  408 , and the non-inverting input of the operational amplifier can be coupled to a reference voltage Vref. Operational amplifier  408  can drive its output to voltage Vo to keep Vin substantially equal to Vref, and can therefore maintain Vin constant or virtually grounded. A person of skill in the art would understand that, in this context, equal can include deviations of up to 15%. Therefore, the gain of sensing circuit  414  can be mostly a function of the ratio of mutual capacitance  424  and the feedback impedance, comprised of resistor  412  and/or capacitor  410 . The output of sensing circuit  414  Vo can be filtered and heterodyned or homodyned by being fed into multiplier  428 , where Vo can be multiplied with local oscillator  430  to produce Vdetect. Vdetect can be inputted into filter  432 . One skilled in the art will recognize that the placement of filter  432  can be varied; thus, the filter can be placed after multiplier  428 , as illustrated, or two filters can be employed: one before the multiplier and one after the multiplier. In some examples, there can be no filter at all. The direct current (DC) portion of Vdetect can be used to determine if a touch or proximity event has occurred. 
     Referring back to  FIG.  2   , in some examples, touch screen  220  can be an integrated touch screen in which touch sensing circuit elements of the touch sensing system can be integrated into the display pixel stackups of a display. The circuit elements in touch screen  220  can include, for example, elements that can exist in LCD or other displays, such as one or more pixel transistors (e.g., thin film transistors (TFTs)), gate lines, data lines, touch node electrodes and common electrodes. In a given display pixel, a voltage between a touch node electrode and a common electrode can control a luminance of the display pixel. The voltage on the touch node electrode can be supplied by a data line through a pixel transistor, which can be controlled by a gate line. It is noted that circuit elements are not limited to whole circuit components, such as a whole capacitor, a whole transistor, etc., but can include portions of circuitry, such as only one of the two plates of a parallel plate capacitor. 
     As previously mentioned, it can be beneficial to combine mutual capacitance and self-capacitance sensing of touch electrodes in a single touch sensor panel. Specifically, examples of the disclosure provide various touch sensing system configurations that can operate the same touch circuitry (e.g., electrodes) in different modes to perform hover, touch, force, and/or stylus sensing and/or guarding functions. These exemplary configurations can improve and/or provide hover, touch, and/or force sensing capabilities to the system while reducing the number of electrodes and corresponding routing traces. 
       FIGS.  5 A- 5 D  illustrate exemplary touch sensor panel configurations with three layers of electrodes according to examples of the disclosure. Specifically, touch sensor panel  500  of  FIG.  5 A  illustrates elongated electrodes  502  (e.g., electrodes with relatively high aspect ratio) with corresponding traces  504  along a first direction on a first layer (e.g., row electrodes), and touch node electrodes  506  and corresponding traces  508  on a second layer, different from the first layer. In some examples, elongated electrodes  502  can be disposed with gaps  562  in between rows and/or columns of touch node electrodes  506 . Corresponding traces  508  can be disposed in the gaps  562  between rows (or columns) of touch node electrodes  506  (e.g., as shown in  FIG.  5 A ). In some examples, traces  508  can be disposed in the same first direction as elongated electrodes  502 . In some examples, elongated electrodes  502  can be disposed over the gaps  562  between rows of touch node electrodes  506  (e.g., closer to the touch surface of touch screen  500  where an object touches the touch screen) such that elongated electrodes  502  completely overlap routing traces  508  of touch node electrodes  506  and, in some examples, partially overlap touch node electrodes  506  (e.g., as shown in  FIG.  5 A ). In some examples, touch sensor panel  500  can include a third layer below the first and second layers (e.g., further away from the touch surface of touch screen  500 ) comprising a continuous conductive material (e.g., ITO) that can be electrically coupled to a voltage source (e.g., can be driven by a voltage source to form a shield) or ground to act as a guard layer (shown in  FIG.  5 B ). In some examples, this voltage source can be the same AC voltage source that is used to stimulate the electrodes on the first and second layers (e.g., at the same frequency, phase and/or amplitude). This configuration of the third layer below the first and second layers can help isolate electrodes  502  and  506  and routing traces  504  and  508  from noise below the third layer (e.g., display circuitry that can interfere with the ability of electrodes  502  and/or  506  to detect changes in capacitance). In some examples, elongated electrodes  502  can be operated as guard electrodes (e.g., coupled to a voltage source or ground) to help isolate traces  508  from noise above the first layer. As will be described in greater detail below, in some examples, elongated electrodes  502  can be operated as self-capacitance electrodes in a self-capacitance mode (e.g., by coupling elongated electrodes  502  to sensing circuitry  314  of  FIG.  3   ), be operated as sense and/or drive electrodes in a mutual capacitance mode (e.g., as described above with reference to  FIG.  4   ), or be operated as guard electrodes (e.g., can be actively driven at a reference voltage (e.g., AC or DC) or can be coupled to ground or any other fixed voltage source) to reduce noise coupled to routing traces  508  (e.g., false positives or parasitic coupling). In some examples, this voltage source can be the same AC voltage source that is used to stimulate the electrodes on the second layer (e.g., at the same frequency, phase and/or amplitude). Similarly, as will be described in greater detail below, touch node electrodes  506  can be operated as self-capacitance electrodes in a self-capacitance mode (e.g., by coupling touch node electrodes  506  to sensing circuitry  314  of  FIG.  3   ) or can be operated as sense and/or drive electrodes (e.g., by being grouped into rows and/or columns) in a mutual capacitance mode (e.g., as described above with reference to  FIG.  4   ). In some examples, while a touch electrode is being sensed (e.g., a self-capacitance electrode or a mutual capacitance sense electrode) to determine the occurrence of a touch, other non-sensed touch electrodes can be driven with the same reference voltage (e.g., the guard signal) as the guard layer(s). In this configuration, the sensed electrodes can be surrounded by other touch electrodes that are also acting as a guard. As each electrode is sensed in turn, the guard signal can be selectively applied to other non-sensed electrodes. It should be understood throughout the examples of the disclosure that, where guarding behavior of an electrode is described, the examples are not limited to any particular mechanism (e.g., passive guarding, active guarding using a guard signal) by which the electrode exhibits such guarding behavior. 
       FIG.  5 B  illustrates a cross-sectional view of touch sensor panel  500  according to examples of the disclosure (e.g., cross section at line A-A′ as illustrated in  FIG.  5 A ).  FIG.  5 B  illustrates a double-sided ITO (DITO) substrate  512  with ITO patterned on both sides. Specifically, elongated electrodes  502  (e.g., column or row electrodes) can be arranged (e.g., disposed) on a first side (e.g., side  550 ) of substrate  512  (e.g., the first layer L 1 ), and touch node electrodes  506  can be disposed on a second side (e.g., side  552 ) of substrate  512  (e.g., the second layer L 2 ). In some examples, the touch sensor panel  500  can further include a cover (e.g., a glass cover in a touch screen configuration) (not shown) disposed on touch surface  558  of touch sensor panel  500 , which can be formed from glass, acrylic, sapphire, and the like. Touch sensor panel  500  can be further composed of a single-sided ITO (SITO) substrate  516  with a coat of ITO disposed on a first side (e.g., side  556 ) of substrate  516 . Specifically, side  556  of substrate  516  can be coated with conductive material (e.g., ITO) to form a continuous guard layer  510  (e.g., the third layer L 3 ) (e.g., as described above with reference to  FIG.  5 A ). In some examples, side  554  of substrate  516  can be coated with adhesive  514  and adhered to the second layer L 2  of touch sensor panel  500 . In some examples, adhesive  514  can be an optically clear adhesive (OCA) and/or a pressure sensitive adhesive (PSA). In some examples, adhesive  514  can be an adhesive that compresses with pressure. Substrate  512  and/or  516  can be made of any transparent substrate material, such as plastic, glass, quartz, silicone, or a rigid or flexible (e.g., compressible or compliant under pressure) composite. In some examples, substrate  512  and  516  can be made of the same material. In some examples, substrate  512  and  516  can be made of different materials. For example, substrate  512  can be made of a rigid material while substrate  516  and/or adhesive  514  can be made of a flexible (e.g., compressible or compliant under pressure) material, such that the distance between touch node electrodes  506  and guard layer  510  (e.g., the distance between L 1  and L 3 ) can change (e.g., reduce) when pressure is applied to touch sensor panel  500 . In another example, substrate  512  and substrate  516  and/or adhesive  514  can be made of a flexible (e.g., compressible or compliant under pressure) material, but the compression between touch node electrodes  506  and guard layer  510  (e.g., between L 2  and L 3 ) can be greater than the compression between elongated electrodes  502  and touch node electrodes  506  (e.g., between L 1  and L 2 ) when pressure is applied to touch sensor panel  500 . It should be noted that while layers L 1 -L 3  are described as being formed by ITO, these layers can be formed any other conductive material. 
       FIG.  5 C  illustrates the operation of touch sensor panel  500  to detect activity of an active stylus in a mutual capacitance mode according to examples of the disclosure. In particular, in some examples, touch sensor panel  500  can be configured in a stylus detection mode. During that mode, elongated electrodes  502  and/or touch node electrodes  506  can be configured to operate as sense electrodes, such as illustrated in  FIG.  4   . Active stylus  518  can generate stimulation signals (effectively operating as a drive electrode). During a stylus scan at touch sensor panel  500 , the stimulation signals can be injected by stylus  518  into the touch sensor panel  500  and can cause mutual capacitive coupling C 1  between the stylus  518  and the elongated electrodes  502  in the first layer (e.g., L 1 ) and/or capacitive coupling C 2  between the stylus  518  and one or more touch node electrodes  506  in the second layer (e.g., L 2 ). The capacitances C 1  and C 2  and/or the changes in capacitances C 1  and C 2  can be sensed at the location of the particular elongated electrode  502  and/or at the location of the particular touch node electrode  506  by one or more touch sensing circuits for processing (e.g., as illustrated in  FIG.  4   ). In some examples, during the stylus scan, stimulation signals are not applied to elongated electrodes  502  and/or touch node electrodes  506  apart from signals generated by the active stylus  518 ; rather, elongated electrodes  502  and/or touch node electrodes  506  are coupled to sense circuitry  414  in  FIG.  4    for sensing stylus  518 . 
       FIG.  5 D  illustrates the operation of touch sensor panel  500  to detect hover (proximity), touch, and/or force of an object (e.g., a finger) according to examples of the disclosure. For example, touch node electrodes  506  in the second layer (e.g., L 2 ) of the touch sensor panel  500  can be operated as self-capacitance touch node electrodes (e.g., as described above with reference to  FIG.  3   ) in a self-capacitance mode. While in this self-capacitance mode, capacitance coupling H sc  (e.g., hovering event) and/or T sc  (e.g., touch event) can occur between object  520  (e.g., finger) and self-capacitance touch node electrode  506 . This capacitance coupling (e.g., H sc  and/or T sc ) at the location of the particular touch node electrode  506  can be detected to indicate a touch or proximity event (e.g., as described above with reference to  FIG.  3   ). Touch sensor panel  500  can also be operated in a mutual capacitance mode. For example, elongated electrodes  502  in the first layer (e.g., L 1 ) of the touch sensor panel  500  can be operated as sense/drive electrodes and touch node electrodes  506  in the second layer (e.g., L 2 ) of the touch sensor panel  500  can be operated as drive/sense electrodes in the mutual capacitance mode. This configuration can cause mutual capacitive coupling T mc  between elongated electrodes  502  and touch node electrodes  506 . When a finger or object  520  approaches the touch node created by an intersection of an elongated electrode  502  and a touch node electrode  506  (or a group of touch node electrodes  506 ), mutual capacitance T mc  can be altered. This change in mutual capacitance T mc  at the location of the intersection of a particular elongated electrode  502  and a particular touch node electrode  506  (or a group of touch node electrodes  506 ) can be detected to indicate a touch or proximity at the location of the touch node (e.g., as described above with reference to  FIG.  4   ). In some examples, the continuous conductive material  510  in the third layer (e.g., L 3 ) can be operated as a drive/sense layer (e.g., as described above with reference to  FIG.  4   ), and touch node electrodes  506  in the second layer (e.g., L 2 ) can be operated as sense/drive electrodes. For example, continuous conduct material  510  can be stimulated by a stimulation signal (e.g., an AC voltage signal). This stimulation signal can be capacitively coupled to touch node electrode  506  (or a group of touch node electrodes  506 ) through mutual capacitance F mc  between conductive material  510  (e.g., drive layer) and touch node electrode(s)  506  (e.g., sense electrodes). When a finger or object  520  approaches the touch node created by the intersections of conductive material  510  (e.g., drive layer) and touch node electrodes  506 , mutual capacitance F mc  can be altered. This change in mutual capacitance F mc  at the location of the intersection of conductive material  510  and a particular touch node electrode  506  can be detected to indicate a touch or proximity event at the location of the touch node (e.g., as described above with reference to  FIG.  4   ). Moreover, when a pressure compliant or compressible material (e.g., a pressure sensitive adhesive (PSA), silicone, or any other material that compresses with pressure) is disposed between touch node electrodes  506  and conductive material  510  (e.g., between layers L 2  and L 3 ), the distance between conductive material  510  and individual touch node electrodes  506  can change, causing mutual capacitance F mc  to change (e.g., as described above with reference to  FIG.  5 B ). This change in mutual capacitance F mc  at the location of the intersection of conductive material  510  and a particular touch node electrode  506  can be detected to indicate a force event at the touch node (e.g., as described above with reference to  FIG.  4   ). 
       FIGS.  5 E- 5 I  illustrate exemplary tables describing different modes of operation for exemplary touch sensor panel configurations with three layers of electrodes according to examples of the disclosure. Specifically, the table illustrated in  FIG.  5 E  shows the different modes in which touch sensor panel  500  can be operated. For example,  FIG.  5 E  shows that touch sensor panel  500  can be used for stylus sensing S (e.g., as described above with reference to  FIG.  5 C ), touch/hover sensing in a self-capacitance configuration SC (e.g., as described above with reference to  FIG.  5 D ), touch sensing in a mutual capacitance configuration MC 1 -MC 2  (e.g., as described above with reference to  FIG.  5 D ), and force sensing F 1 -F 4  (e.g., as described above with reference to  FIG.  5 D ). For example, the table in  FIG.  5 E  illustrates that stylus sensing mode S can be performed by operating the elongated electrodes  502  in the first layer (e.g., L 1 ) and the touch node electrodes  506  in the second layer (e.g., L 2 ) of touch sensor panel  500  as sense lines/electrodes (e.g., by coupling elongated electrodes  502  and touch node electrodes  506  to sensing circuitry  414  in  FIG.  4   ) and operating the conductive material  510  in the third layer (e.g., L 3 ) as a guard electrode (e.g., by operating the conductive material  510  at a reference voltage as previously described, such as an AC voltage having the same amplitude and/or frequency as the stimulation signal provided by the stylus). 
     In another example, the table in  FIG.  5 E  illustrates that touch/hover sensing mode SC can be performed by operating elongated electrodes  502  in the first layer (e.g., L 1 ) of touch sensor panel  500  as guard electrodes (e.g., by operating one or more elongated electrodes  502  at a reference voltage, as previously described) or as self-capacitance touch electrodes (e.g., as described above with reference to  FIG.  3   ), operating the touch node electrodes  506  in the second layer (e.g., L 2 ) of touch sensor panel  500  as self-capacitance touch node electrodes (e.g., as described above with reference to  FIG.  3   ) and operating the elongated electrodes  502  in the first layer (e.g., L 1 ) and the conductive material  510  disposed on the third layer (e.g., L 3 ) of the touch sensor panel  500  as guard electrode (e.g., by operating the conductive material  510  at a reference voltage, as previously described). 
     In another example, the table in  FIG.  5 E  illustrates that touch sensing mode MC 1  can be performed by operating elongated electrodes  502  in the first layer (e.g., L 1 ) of touch sensor panel  500  as sense lines/electrodes (e.g., coupling elongated electrodes  502  to sensing circuitry  414  of  FIG.  4   ), operating touch node electrodes  506  in the second layer (e.g., L 2 ) of touch sensor panel  500  as drive lines/electrodes (e.g., coupling touch node electrodes  506  to stimulation signal  406  of  FIG.  4   ), and operating the conductive material  510  in the third layer (e.g., L 3 ) as a guard electrode (e.g., by operating the conductive material  510  at a reference voltage as previously described). In another example, the table in  FIG.  5 E  illustrates that touch sensing mode MC 2  can be performed by operating elongated electrodes  502  in the first layer (e.g., L 1 ) of touch sensor panel  500  as drive lines/electrodes (e.g., coupling elongated electrodes  502  to stimulation signal  406  of  FIG.  4   ), operating touch node electrodes  506  in the second layer (e.g., L 2 ) of touch sensor panel  500  as sense lines/electrodes (e.g., coupling elongated electrodes  506  to sensing circuitry  414  of  FIG.  4   ), and operating the conductive material  510  in the third layer (e.g., L 3 ) as a guard electrode (e.g., by operating the conductive material  510  at a reference voltage as previously described). 
     In another example, the table in  FIG.  5 E  illustrates that force sensing mode F 1  can be performed by operating elongated electrodes  502  in the first layer (e.g., L 1 ) of touch sensor panel  500  as sense lines/electrodes (e.g., coupling elongated electrodes  502  to sensing circuitry  414  of  FIG.  4   ) and the conductive material  510  in the third layer (e.g., L 3 ) of touch sensor panel  500  as a drive electrode (e.g., coupling conductive material  510  to stimulation signal  406  of  FIG.  4   ). In some examples, touch node electrodes  506  in the second layer (e.g., L 2 ) of touch sensor panel  500  can be operated as sense electrodes (e.g., as described above with reference to  FIG.  4   ), drive electrodes (e.g., as described above with reference to  FIG.  4   ), self-capacitance touch node electrodes (e.g., as described above with reference to  FIG.  3   ), or driven at a reference voltage (e.g., an AC signal having the same amplitude and/or frequency as the AC signal used to drive the conductive material  510  in the third layer L 3 ), or can be tired to ground, or left floating during the force sensing mode F 1 . In another example, the table in  FIG.  5 E  illustrates that force sensing mode F 2  can be performed by operating elongated electrodes  502  in the first layer (e.g., L 1 ) of touch sensor panel  500  as drive lines/electrodes (e.g., coupling elongated electrodes  502  to stimulation signal  406  of  FIG.  4   ) and the conductive material  510  in the third layer (e.g., L 3 ) of touch sensor panel  500  as a sense electrode (e.g., coupling conductive material  510  to sensing circuitry  414  of  FIG.  4   ). In some examples, touch node electrodes  506  in the second layer (e.g., L 2 ) of touch sensor panel  500  can be operated as sense lines/electrodes (e.g., as described above with reference to  FIG.  4   ), drive electrodes (e.g., as described above with reference to  FIG.  4   ), self-capacitance touch node electrodes (e.g., as described above with reference to  FIG.  3   ), or driven at a reference voltage (e.g., an AC signal having the same amplitude and/or frequency as the AC signal used to drive the conductive material  510  in the third layer L 3 ), or can be tied to ground, or left floating during the force sensing mode F 2 . In another example, the table in  FIG.  5 E  illustrates that force sensing mode F 3  can be performed by operating touch node electrodes  506  in the second layer (e.g., L 2 ) of touch sensor panel  500  as sense lines/electrodes (e.g., coupling touch node electrodes  506  to sensing circuitry  414  of  FIG.  4   ) and the conductive material  510  in the third layer (e.g., L 3 ) of touch sensor panel  500  as a drive electrode (e.g., coupling conductive material  510  to stimulation signal  406  of  FIG.  4   ). In some examples, elongated electrodes  502  in the first layer (e.g., L 1 ) of touch sensor panel  500  can be operated as sense electrodes (e.g., as described above with reference to  FIG.  4   ), drive electrodes (e.g., as described above with reference to  FIG.  4   ), self-capacitance touch node electrodes (e.g., as described above with reference to  FIG.  3   ), or driven at a reference voltage (e.g., an AC signal having the same amplitude and/or frequency as the AC signal used to drive the conductive material  510  in the third layer L 3 ), or can be tied to ground, or left floating during the force sensing mode F 3 . In another example, the table in  FIG.  5 E  illustrates that force sensing mode F 4  can be performed by operating touch node electrodes  506  in the second layer (e.g., L 2 ) of touch sensor panel  500  as drive lines/electrodes (e.g., coupling touch node electrodes  506  to stimulation signal  406  of  FIG.  4   ) and the conductive material  510  in the third layer (e.g., L 3 ) of touch sensor panel  500  as a sense electrode (e.g., coupling conductive material  510  to sensing circuitry  414  of  FIG.  4   ). In some examples, elongated electrodes  502  in the first layer (e.g., L 1 ) of touch sensor panel  500  can be operated as sense lines/electrodes (e.g., as described above with reference to  FIG.  4   ), drive electrodes (e.g., as described above with reference to  FIG.  4   ), self-capacitance touch node electrodes (e.g., as described above with reference to  FIG.  3   ), or driven at a reference voltage (e.g., an AC signal having the same amplitude and/or frequency as the AC signal used to drive the conductive material  510  in the third layer L 3 ), or can be tied to ground, or left floating during the force sensing mode F 4 . 
       FIG.  5 F  illustrates a table showing additional details about stylus sensing mode S that can be performed using the touch sensor panel of the disclosure. For example,  FIG.  5 F  illustrates that stylus sensing mode S-A can be performed by operating the elongated electrodes  502  in the first layer (e.g., L 1 ) as sense lines/electrodes (e.g., by coupling elongated electrodes  502  to sensing circuitry  414  of  FIG.  4   ), operating at least one of the touch node electrodes  506  in the second layer (e.g., L 2 ) of touch sensor panel  500  as sense line(s)/electrode(s) (e.g., by coupling at least one of the touch node electrodes  506  to sensing circuitry  414  of  FIG.  4   ) while coupling the remaining touch node electrodes  506  to a voltage source (e.g., operate them as guard) and/or ground, and operating the conductive material  510  in the third layer (e.g., L 3 ) as a guard electrode. It should be understood that the electrodes operating as sense lines/electrodes need not be sensed at the same time (e.g., can be sensed sequentially). In another example,  FIG.  5 F  illustrates that stylus sensing mode S-B can be performed by operating the elongated electrodes  502  in the first layer (e.g., L 1 ) as sense lines/electrodes, operating at least one row/column of touch node electrodes  506  (e.g., grouping touch node electrodes  506  to form a row or a column) in the second layer (e.g., L 2 ) of touch sensor panel  500  as sense line(s)/electrode(s) while coupling the remaining touch node electrodes  506  to a voltage source (e.g., operate them as guard) and/or ground, and operating the conductive material  510  in the third layer (e.g., L 3 ) of the touch sensor panel  500  as a guard electrode. It should be understood that the row(s)/column(s) of touch node electrodes  506  operating as sense lines/electrodes need not be sensed at the same time (e.g., can be sensed sequentially). In another example,  FIG.  5 F  illustrates that stylus sensing mode S-C can be performed by operating the elongated electrodes  502  in the first layer (e.g., L 1 ) as sense lines/electrodes, operating all rows/columns of touch node electrodes  506  (e.g., grouping touch node electrodes to form rows or columns) in the second layer (e.g., L 2 ) of touch sensor panel  500  as sense lines/electrodes, and operating the conductive material  510  in the third layer (e.g., L 3 ) as a guard electrode (e.g., by operating the conductive material  510  at a reference voltage as previously described). 
       FIG.  5 G  illustrates a table showing additional touch panel configurations in which touch/hover sensing mode SC can be performed. For example,  FIG.  5 G  illustrates that touch/hover sensing mode SC-A can be performed by operating all of the touch node electrodes  506  in the second layer (e.g., L 2 ) of touch sensor panel  500  as self-capacitance touch node electrodes (e.g., as described above with reference to  FIG.  3   ) and operating the elongated electrodes  502  in the first layer (e.g., L 1 ) and the conductive material disposed  510  on the third layer (e.g., L 3 ) of the touch sensor panel  500  as guard (e.g., by operating the elongated electrodes  502  and the conductive material  510  at a reference voltage as previously described). In another example,  FIG.  5 G  illustrates that touch/hover sensing mode SC-B can be performed by operating a subset of the touch node electrodes  506  (e.g., a group, a row, a column, etc.) in the second layer (e.g., L 2 ) of touch sensor panel  500  as self-capacitance touch node electrodes (e.g., as described above with reference to  FIG.  3   ) while coupling the remaining touch node electrodes  506  to a voltage source (e.g., operate them as guard), and operating the elongated electrodes  502  in the first layer (e.g., L 1 ) and the conductive material disposed on the third layer (e.g., L 3 ) of the touch sensor panel  500  as guard. For example, in a 3×3 touch node electrode configuration, the subset of the touch node electrodes  506  operated as self-capacitance touch node electrodes can be the first row of the 3×3 touch node electrode configuration and the remaining touch node electrodes  506  in the second and third rows of the 3×3 touch node electrode configuration can be coupled to a voltage source (e.g., operated as guard). In another example,  FIG.  5 G  illustrates that touch/hover sensing mode SC-C can be performed by operating a subset of the touch node electrodes  506  (e.g., a group, a row, a column, etc.) in the second layer (e.g., L 2 ) of touch sensor panel  500  as self-capacitance touch node electrodes (e.g., as described above with reference to  FIG.  3   ) while coupling the remaining touch node electrodes  506  to ground, and operating the elongated electrodes  502  in the first layer (e.g., L 1 ) and the conductive material disposed on the third layer (e.g., L 3 ) of the touch sensor panel  500  as guard (e.g., by operating the elongated electrodes  502  and the conductive material  510  at a reference voltage as previously described). For example, in a 3×3 touch node electrode configuration, the subset of the touch node electrodes  506  operated as self-capacitance touch node electrodes can be the second row of the 3×3 touch node electrode configuration and the remaining touch node electrodes  506  in the first and third rows of the 3×3 touch node electrode configuration can be coupled to ground. In another example,  FIG.  5 G  illustrates that touch/hover sensing mode SC-D can be performed by operating a first subset of touch node electrodes  506  (e.g., a group, a row, a column, etc.) in the second layer (e.g., L 2 ) of touch sensor panel  500  as self-capacitance touch node electrodes (e.g., as described above with reference to  FIG.  3   ), operating a second subset of touch node electrodes  506  (e.g., a group, a row, a column, etc.) in the second layer (e.g., L 2 ) of touch sensor panel  500  as guards, coupling the remaining touch node electrodes  506  in the second layer of touch sensor panel  500  to ground, and operating the elongated electrodes  502  in the first layer (e.g., L 1 ) and the conductive material disposed on the third layer (e.g., L 3 ) of the touch sensor panel  500  as guard (e.g., by operating the elongated electrodes  502  and the conductive material  510  at a reference voltage as previously described). For example, in a 3×3 touch node electrode configuration, the first row of touch node electrodes  506  in the 3×3 touch node electrode configuration can be operated as self-capacitance touch node electrodes, the second row of touch node electrodes  506  in the 3×3 touch node electrode configuration can be coupled to a voltage source (e.g., operated as guard), and the third row of touch node electrodes  506  in the 3×3 touch node electrode configuration can be coupled to ground. It should be understood that while the elongated electrodes  502  in the first layer (e.g., L 1 ) of the touch sensor panel  500  are illustrated as being operated as guard in  FIG.  5 G , in some examples, one or more elongated electrodes  502  can be operated as self-capacitance touch electrodes (e.g., as described above with reference to  FIG.  3   ) during any of the described touch/hover sensing mode SC of  FIG.  5 G . 
       FIG.  5 H  illustrates a table showing additional details about touch sensing mode MC 1  that can be performed using the touch sensor panel of the disclosure. For example,  FIG.  5 H  illustrates that touch sensing mode MC 1 -A can be performed by operating elongated electrodes  502  in the first layer (e.g., L 1 ) of touch sensor panel  500  as sense lines/electrodes (e.g., by coupling elongated electrodes  502  to sensing circuitry  414  of  FIG.  4   ), operating at least one touch node electrode  506  in the second layer (e.g., L 2 ) of touch sensor panel  500  as drive line(s)/electrode(s) (e.g., by coupling at least one of the touch node electrodes  506  to stimulation signal  406  of  FIG.  4   ) while coupling the remaining touch node electrodes  506  to a voltage source (e.g., operate them as guard) and/or ground, and operating the conductive material  510  in the third layer (e.g., L 3 ) as a guard layer (e.g., as described above with reference to  FIGS.  4  and  5 D ). In another example,  FIG.  5 H  illustrates that touch sensing mode MC 1 -B can be performed by operating elongated electrodes  502  in the first layer (e.g., L 1 ) of touch sensor panel  500  as sense lines/electrodes (e.g., by coupling elongated electrodes  502  to sensing circuitry  414  of  FIG.  4   ), operating at least one row or column of touch node electrodes  506  (e.g., by grouping touch node electrodes to form rows or columns) in the second layer (e.g., L 2 ) of touch sensor panel as drive line(s)/electrode(s) (e.g., by coupling at least one row or column of the touch node electrodes  506  to stimulation signal  406  of  FIG.  4   ) while coupling the remaining touch node electrodes  506  to a voltage source (e.g., operate them as guard) and/or ground, and operating the conductive material  510  in the third layer (e.g., L 3 ) as a guard layer (e.g., as described above with reference to  FIGS.  4  and  5 D ). For example, in a 3×3 touch node electrode configuration, the first row of touch node electrodes  506  in the 3×3 touch node electrode configuration can be operated as a drive electrode (e.g., by coupling the first row of touch node electrodes  506  to stimulation signal  406  of  FIG.  4   ) and the remaining touch node electrodes  506  in the second and third rows of the 3×3 touch node electrode configuration can be coupled to a voltage source (e.g., operated as guard) and/or ground. In another example,  FIG.  5 H  illustrates that touch sensing mode MC 1 -C can be performed by operating elongated electrodes  502  in the first layer (e.g., L 1 ) of touch sensor panel  500  as sense electrodes (e.g., by coupling elongated electrodes  502  to sensing circuitry  414  of  FIG.  4   ), operating all rows or columns of touch node electrodes  506  (e.g., by grouping touch node electrodes to form rows or columns) in the second layer (e.g., L 2 ) of touch sensor panel as a drive electrodes, and operating the conductive material  510  in the third layer (e.g., L 3 ) as a guard layer (e.g., as described above with reference to  FIGS.  4  and  5 D ). 
       FIG.  5 I  illustrates a table showing additional details about touch sensing mode MC 2  that can be performed using the touch sensor panel of the disclosure. For example,  FIG.  5 I  illustrates that touch sensing mode MC 2 -A can be performed operating elongated electrodes  502  in the first layer (e.g., L 1 ) of touch sensor panel  500  as drive electrodes (e.g., by coupling elongated electrodes  502  to stimulation signal  406  of  FIG.  4   ), operating at least one touch node electrode  506  in the second layer (e.g., L 2 ) of touch sensor panel  500  as a sense line/electrode (e.g., by coupling at least one touch node electrode  506  to sensing circuitry  414  of  FIG.  4   ), and operating the conductive material  510  in the third layer (e.g., L 3 ) as a guard layer (e.g., as described above with reference to  FIGS.  4  and  5 D ). In another example,  FIG.  5 H  illustrates that touch sensing mode MC 2 -B can be performed by operating elongated electrodes  502  in the first layer (e.g., L 1 ) of touch sensor panel  500  as drive electrodes (e.g., by coupling elongated electrodes  502  to stimulation signal  406  of  FIG.  4   ), operating at least one row or column of touch node electrodes  506  (e.g., by grouping touch node electrodes to form rows or columns) in the second layer (e.g., L 2 ) of touch sensor panel  500  as sense line(s)/electrode(s) (e.g., by coupling at least one row or column of touch node electrodes  506  to sensing circuitry  414  of  FIG.  4   ) while coupling the remaining touch node electrodes  506  to a voltage source (e.g., operate them as guard) and/or ground, and operating the conductive material  510  in the third layer (e.g., L 3 ) as a guard electrode (e.g., by operating the conductive material  510  at a reference voltage as previously described). For example, in a 3×3 touch node electrode configuration, the first row of touch node electrodes  506  in the 3×3 touch node electrode configuration can be operated as a sense electrode (e.g., by coupling the first row of touch node electrodes  506  to sensing circuitry  414  of  FIG.  4   ) and the remaining touch node electrodes  506  in the second and third rows of the 3×3 touch node electrode configuration can be coupled to a voltage source (e.g., operated as guard) and/or ground. In another example,  FIG.  5 H  illustrates that touch sensing mode MC 2 -C can be performed by operating elongated electrodes  502  in the first layer (e.g., L 1 ) of touch sensor panel  500  as drive electrodes (e.g., by coupling elongated electrodes  502  to stimulation signal  406  of  FIG.  4   ), operating all rows or columns of touch node electrodes  506  (e.g., by grouping touch node electrodes to form rows or columns) in the second layer (e.g., L 2 ) of touch sensor panel  500  as a sense electrodes (e.g., by coupling all rows or columns of touch node electrodes  506  to sensing circuitry  414  of  FIG.  4   ), and operating the conductive material  510  in the third layer (e.g., L 3 ) as a guard layer (e.g., as described above with reference to  FIGS.  4  and  5 D ). 
       FIGS.  5 J- 5 M  illustrate additional exemplary touch sensor panel configurations according to examples of the disclosure. For example,  FIG.  5 J  illustrates a touch sensor panel configuration similar to the configuration shown in  FIG.  5 A , and can include a plurality of elongated electrodes  502  arranged along a first direction (e.g., horizontal direction) on a first layer (e.g., creating rows with multiple electrodes), a plurality of elongated electrodes  507  (with an aspect ratio higher than touch node electrodes  506  of  FIG.  5 A  but lower than the plurality of elongated electrodes  502 ) with corresponding traces  508  arranged along a second direction (e.g., a vertical direction) across and under the plurality of elongated electrodes  502  on a second layer, different from the first layer, and without showing routing traces  504  for simplicity. In some examples, routing traces  504  can be coupled to elongated electrodes  502  at the left and/or right end of each elongated electrodes  502  and routed to drive and/or sensing circuitry (e.g., as described above with reference to  FIGS.  3 - 4   ) in any direction (e.g., routing up, down, left, right). While  FIG.  5 J  illustrates two elongated electrodes  502  arranged across each elongated electrode  507 , it should be understood that less (e.g., none or one) or more (e.g., three, four) elongated electrode(s)  502  can be arranged across elongated electrodes  507 . In some examples, additional layers can be included (e.g., any of the layers described above with reference to  FIGS.  5 A- 5 I  (e.g., a third layer below the first and second layers comprising a continuous conductive material (e.g., ITO)), any of the layers described below with reference to  FIGS.  6 - 7   ). It should be understood that the touch sensor configurations shown in  FIG.  5 I  can be used to perform any of the modes of operation described in this disclosure (e.g., the plurality of elongated electrodes  502  can correspond to the electrodes on the first layer (e.g., L 1 ) and the plurality of elongated electrodes  507  can correspond to the electrodes on the second layer (e.g., L 2 ) and with additional third and/or fourth layers as described with reference to  FIGS.  5 A- 5 I  and  FIGS.  6 - 7   ). It should also be understood that each elongated electrode  502  or  507  can be separately addressable when performing self-capacitance and/or mutual capacitance sensing of those electrodes (e.g., as described above with reference to  FIGS.  3 - 4   ). For example, during a mutual capacitance mode, electrodes  507  can be driven with a drive signal (e.g., all electrodes  507  in a column, though separately addressable, can be driven with the same drive signal; or, in some embodiments, different electrodes in a given column can be driven with different drive signals), and electrodes  502  can be sensed. As another example, during a self-capacitance mode, electrodes  502  can be individually sensed for self-capacitance (e.g., using different sensing circuitry for each, or sensing each sequentially using the same sensing circuitry), and electrodes  507  can also be individually sensed for self-capacitance (e.g., using different sensing circuitry for each, or sensing each sequentially using the same sensing circuitry). Other sensing configurations as described with reference to  FIGS.  5 E- 5 I  can additionally or alternatively be implemented in the configuration of  FIG.  5 I , as described above. 
       FIG.  5 K  illustrates a touch sensor panel configuration similar to the configuration shown in  FIG.  5 I , but with segments of elongated electrodes  502  extending along the second direction (e.g., the vertical direction) on the first layer over (or partially over) gaps  562  in that second direction. For example, row electrodes  502  can extend up over (or substantially over) gaps  562  (e.g., as shown by segments  502 A in  FIG.  5 K ) and extend down over (or substantially over) gaps  562  (e.g., as shown by segment  502 B in  FIG.  5 K ). In some examples, the lengths and/or shapes of segments  502 A and  502 B are the same (or substantially the same). In some examples, the lengths and/or shapes of segments  502 A and  502 B vary. It should be understood that the segments  502 A and  502 B can come close to without touching other electrodes on that same first layer (e.g., other elongated electrodes  502  (including segments  502 A and/or  502 B)). In this way, the touch sensor panel configuration shown in  FIG.  5 K  can improve optical uniformity. This configuration can also reduce noise coupling to routing traces  508  for electrodes  507  (e.g., when row electrodes  502  are operated as guard electrodes, such as actively driven at a reference voltage (e.g., AC or DC) or coupled to ground or any other fixed voltage source as described above). Thus, electrodes  502  including segments  502 A and  502 B can be configured to shield traces  508  from above, in addition to being configured for use in touch sensing operations described with reference to  FIGS.  5 A- 5 I . In some examples, segments  502 A and/or  502 B can partially overlap touch electrodes  507  (e.g., as shown in  FIG.  5 K ). The remaining details of  FIG.  5 K  can be the same as those of  FIG.  5 J . It should be understood that the touch sensor configuration shown in  FIG.  5 K  can be used to perform any of the modes of operation described in this disclosure, including those described with reference to  FIGS.  5 A- 5 I  (e.g., the plurality of elongated electrodes  502  can correspond to the electrodes on the first layer (e.g., L 1 ) and the plurality of elongated electrodes  507  can correspond to the electrodes on the second layer (e.g., L 2 ) and with additional third and/or fourth layers as described with reference to  FIGS.  5 A- 5 I  and  FIGS.  6 - 7   ). It should also be understood that each elongated electrode  502  or  507  can be separately addressable when performing self-capacitance and/or mutual capacitance sensing of those electrodes (e.g., as described above with reference to  FIGS.  3 - 4   ). 
       FIG.  5 L  illustrates a touch sensor panel configuration similar to the configuration shown in  FIG.  5 J , but with a plurality of elongated electrodes  502  with corresponding traces  504  arranged along a first direction (e.g., horizontal direction) on a first layer (e.g., creating rows with multiple electrodes), and elongated electrodes  507  (with a relatively higher aspect ratio than in  FIG.  5 J ) arranged along a second direction (e.g., a vertical direction) on a second layer, different from the first layer. In some examples, each elongated electrode  502  can be arranged across and over one or more elongated electrodes  507  (e.g., as shown in  FIG.  5 L ). While  FIG.  5 L  illustrates elongated electrodes  502  arranged across two elongated electrodes  507 , it should be understood that each elongated electrode  502  can be arranged across less (e.g., none or one) or more (e.g., three or more) elongated electrodes  507 . It should be understood that the touch sensor panel configuration shown in  FIG.  5 L  can be used to perform any of the modes of operation described in this disclosure, including those described with reference to  FIGS.  5 A- 5 I  (e.g., the plurality of elongated electrodes  502  can correspond to the electrodes on the first layer (e.g., L 1 ) and the plurality of elongated electrodes  507  can correspond to the electrodes on the second layer (e.g., L 2 ) and with additional third and/or fourth layers as described with reference to  FIGS.  5 A- 5 I  and  FIGS.  6 - 7   ). It should also be understood that each elongated electrode  502  or  507  can be separately addressable when performing self-capacitance and/or mutual capacitance sensing of those electrodes (e.g., as described above with reference to  FIGS.  3 - 4   ). For example, during a mutual capacitance mode, electrodes  507  can be driven with a drive signal, and electrodes  502  can be sensed (e.g., all electrodes  502  in a given row, though separately addressable, can be sensed with the same sense circuitry; or, in some embodiments, different electrodes in a given row can be sensed with different sense circuitry). As another example, during a self-capacitance mode, electrodes  502  can be individually sensed for self-capacitance (e.g., using different sensing circuitry for each, or sensing each sequentially using the same sensing circuitry), and electrodes  507  can also be individually sensed for self-capacitance (e.g., using different sensing circuitry for each, or sensing each sequentially using the same sensing circuitry). Other sensing configurations as described with reference to  FIGS.  5 E- 5 I  can additionally or alternatively be implemented in the configuration of  FIG.  5 L , as described above. 
       FIG.  5 M  illustrates a touch sensor panel configuration similar to the configuration shown in  FIG.  5 L , but with a plurality of elongated electrodes  502  with corresponding traces  504  arranged along a first direction (e.g., horizontal direction) on a first layer (e.g., creating rows with multiple electrodes), such as described with reference to  FIG.  5 L , and with a plurality of elongated electrodes  507  extending along a second direction (e.g., a vertical direction) on a second layer, different from the first layer (e.g., creating columns with multiple electrodes), such as described above with reference to  FIG.  5 J . In some example, two or more elongated electrodes  507  and two or more elongated electrodes  502  can be disposed together to form super nodes  527 . For example,  FIG.  5 M  illustrates super nodes  527 A- 527 D each formed by two elongated electrodes  502  overlapping two elongated electrodes  507  (e.g., super node  527 A is formed by elongated electrodes  502 A,  502 B,  507 A, and  507 B). It should be understood that the touch sensor configuration shown in  FIG.  5 M  can be used to perform any of the modes of operation described in this disclosure, including those described with reference to  FIGS.  5 A- 5 I  (e.g., the plurality of elongated electrodes  502  can correspond to the electrodes on the first layer (e.g., L 1 ) and the plurality of elongated electrodes  507  can correspond to the electrodes on the second layer (e.g., L 2 ) and with additional third and/or fourth layers as described with reference to  FIGS.  5 A- 5 I  and  FIGS.  6 - 7   ). For example, during a mutual capacitance mode, electrodes  507  can be driven with a drive signal (e.g., all electrodes  507  in a column, though separately addressable, can be driven with the same drive signal; or, in some embodiments, different electrodes in a given column can be driven with different drive signals), and electrodes  502  can be sensed (e.g., all electrodes  502  in a given row, though separately addressable, can be sensed with the same sense circuitry; or, in some embodiments, different electrodes in a given row can be sensed with different sense circuitry). As another example, during a self-capacitance mode, electrodes  502  can be individually sensed for self-capacitance (e.g., using different sensing circuitry for each, or sensing each sequentially using the same sensing circuitry), and electrodes  507  can also be individually sensed for self-capacitance (e.g., using different sensing circuitry for each, or sensing each sequentially using the same sensing circuitry). It should also be understood that each super node  527  can be used to perform any of the modes of operation described in this disclosure within each super node  527  (e.g., elongated electrodes  502 A and  502 B can correspond to the electrodes on the first layer (e.g., L 1 ) and elongated electrodes  507 A and  507 B can correspond to the electrodes on the second layer (e.g., L 2 ) and with additional third and/or fourth layers as described with reference to  FIGS.  5 A- 5 I  and  FIGS.  6 - 7   ). It should also be understood that each super node  527  can perform a different mode of operation or each super node can perform the same mode of operation (e.g., each of super nodes  527 A- 527 D can concurrently perform a different mode of operation of  FIGS.  5 E- 5 I , the same mode of operation of  FIGS.  5 E- 5 I , or a combination thereof (e.g., a subset of super nodes performed the same mode of operation while the other super nodes perform different modes of operation)). It should also be understood that each elongated electrode  502  or  507  can be separately addressable when performing self-capacitance and/or mutual capacitance sensing of those electrodes (e.g., as described above with reference to  FIGS.  3 - 4   ). In some examples, each super node can be sensed sequentially or simultaneously. 
       FIGS.  6 A- 6 D  illustrate exemplary touch sensor panel configurations with four layers of electrodes according to examples of the disclosure. Specifically, touch sensor panel  600  of  FIG.  6 A  illustrates elongated electrodes  602  with corresponding traces  604  along a first direction on a first layer (e.g., in a row configuration), elongated electrodes  622  with corresponding traces  624  along a second direction, different than the first direction (e.g., in a column configuration), on a second layer, different from the first layer, and touch node electrodes  606  and corresponding traces  608  on a third layer, different from the first and second layers. In some examples, touch node electrodes  606  can be disposed with gaps  662  in between rows and/or columns of touch node electrodes  606 . Corresponding traces  608  can be disposed in the gaps  662  between rows (or columns) of touch node electrodes  606  (e.g., as shown in  FIG.  6 A ). In some examples, traces  608  can be disposed in the same first direction as elongated electrodes  604 . In some examples, elongated electrodes  602  can be disposed over the gaps  662  between rows of touch node electrodes  606  (e.g., closer to the touch surface of touch screen  600  where an object touches the touch screen) such that elongated electrodes  602  completely overlap routing traces  608  of touch node electrodes  606  and, in some examples, partially overlap touch node electrodes  606  (e.g., as shown in  FIG.  6 A ). In some examples, touch node electrodes  606  can be disposed with gaps  662  in between columns of touch node electrodes  606 . Corresponding traces  608  can be disposed in the gaps  662  between columns of touch node electrodes  606  (e.g., as shown in  FIG.  6 A ). In some examples, traces  608  can be disposed in the same first direction as elongated electrodes  622 . In some examples, elongated electrodes  622  can be disposed over the gaps  662  between columns of touch node electrodes  606  (e.g., closer to the touch surface of touch screen  600  where an object touches the touch screen) such that elongated electrodes  602  completely overlap routing traces  608  of touch node electrodes  606  and, in some examples, partially overlap touch node electrodes  606 . In some examples, touch sensor panel  500  can include a fourth layer below the first, second, and third layers comprising of continuous conductive material (e.g., ITO) that can be electrically coupled to a voltage source (e.g., can be driven by a voltage source to form a shield) or ground to act as a guard layer (as shown in  FIG.  6 B ). In some examples, this voltage source can be the same AC voltage source that is used to stimulate the electrodes on the first, second, and third layers (e.g., at the same frequency, phase and/or amplitude). This configuration of the fourth layer below the first, second, and third layers can help isolate electrodes  602 ,  606 ,  622 , and routing traces  604 ,  608 , and  624  from noise below the fourth layer (e.g., display circuitry that can interfere with the ability of electrodes  602 ,  606 , and/or  622  to detect changes in capacitance). In some examples, elongated electrodes  602  and/or  622  can be operated as guard electrodes (e.g., coupled to a voltage source or ground) to help isolate traces  608  from noise above the first layer. As will be described in greater detail below, in some examples, elongated electrodes  602  and/or  622  can be operated as self-capacitance electrodes in a self-capacitance mode (e.g., as described above with reference to  FIG.  3   ), be operated as sense and/or drive electrodes in a mutual capacitance mode (e.g., as described above with reference to  FIG.  4   ), or be operated as guard electrodes (e.g., can be actively driven at a reference voltage (e.g., AC or DC) or can be coupled to ground or any other fixed voltage source) to reduce noise coupled to routing traces  608  (e.g., false positives or parasitic coupling). In some examples, this voltage source can be the same AC voltage source that is used to stimulate the electrodes on the third layer (e.g., at the same frequency, phase and/or amplitude). Similarly, touch node electrodes  606  can be operated as self-capacitance electrodes in a self-capacitance mode (e.g., as described above with reference to  FIG.  3   ) or can be operated as sense and/or drive electrodes (e.g., by being grouped in lines) in a mutual capacitance mode (e.g., as described above with reference to  FIG.  4   ). In some examples, while a touch electrode is being sensed (e.g., a self-capacitance electrode or a mutual capacitance sense electrode) to determine the occurrence of a touch, other non-sensed touch electrodes can be driven with the same reference voltage (e.g., the guard signal) as the guard layer(s). In this configuration, the sensed electrodes can be surrounded by other touch electrodes that are also acting as a guard. As each electrode is sensed in turn, the guard signal can be selectively applied to other non-sensed electrodes. It should be understood throughout the examples of the disclosure that, where guarding behavior of an electrode is described, the examples are not limited to any particular mechanism (e.g., passive guarding, active guarding using a guard signal) by which the electrode exhibits such guarding behavior. 
       FIG.  6 B  illustrates a cross-sectional view of touch sensor panel  600  according to examples of the disclosure (e.g., cross-section at line A-A′ as illustrated in  FIG.  6 A ).  FIG.  6 B  illustrates a first double-sided ITO (DITO) substrate  612  with ITO patterned on both sides. Specifically, elongated electrodes  622  can be arranged (e.g., disposed) on a first side (e.g., side  650 ) of substrate  612  (e.g., the first layer L 1 ) in a row/column configuration and elongated electrodes  602  can be arranged (e.g., disposed) on a second side (e.g., side  652 ) of substrate  612  (e.g., the second layer L 2 ) in a column/row configuration. In some examples, the touch sensor panel  600  can further include a cover (e.g., a glass cover in a touch screen configuration) (not shown) disposed on touch surface  658  of touch sensor panel  600 , which can be formed from glass, acrylic, sapphire, and the like. Touch sensor panel  600  can be further composed of a second double-sided ITO (DITO) substrate  616  with touch node electrodes  606  disposed on a first side (e.g., side  654 ) of substrate  616  (e.g., the third layer L 3 ) and a coat of ITO disposed on a second side (e.g., side  656 ). Specifically, side  656  of substrate  616  can be coated with conductive material (e.g., ITO) to form a continuous guard layer  610  (e.g., the fourth layer L 4 ) (e.g., as described above with reference to  FIG.  6 A ). In some examples, the side of the third layer L 3  opposite substrate  616  can be coated with adhesive  614  and adhered to the second layer L 2  of touch sensor panel  600  (e.g., the layer of elongated electrodes  602  can be adhered to the layers of touch node electrodes  606 ). In some examples, adhesive  614  can be an optically clear adhesive (OCA) and/or a pressure sensitive adhesive (PSA). In some examples, adhesive  514  can be an adhesive that compresses with pressure. Substrate  612  and/or  616  can be made of any transparent substrate material, such as plastic, glass, quartz, silicone, or a rigid or flexible (e.g., compressible or compliant under pressure) composite. In some examples, substrate  612  and  616  can be made of the same material. In some examples, substrate  612  and  616  can be made of different material. In some examples, substrate  616  and/or adhesive  614  can be made of a flexible (e.g., compressible or compliant under pressure) material, such that the distance between L 1  and L 3  and/or L 4 , between L 2  and L 3  and/or L 4 , and/or between L 3  and L 4  can change (e.g., reduce) when pressure is applied to touch sensor panel  600 . It should be noted that while layers L 1 -L 4  are described as being formed by ITO, these layers can be formed any other conductive material. 
       FIG.  6 C  illustrates the operation of touch sensor panel  600  to detect activity of an active stylus in a mutual capacitance mode according to examples of the disclosure. In particular, in some examples, touch sensor panel  600  can be configured in a stylus detection mode. During that mode, elongated electrodes  602 , elongated electrodes  622 , and/or touch node electrodes  606  can be configured to operate as sense electrodes (e.g., by coupling elongated electrodes  602 , elongated electrodes  622 , and/or touch node electrodes  606  to sensing circuitry  414  of  FIG.  4   ). An active stylus  618  can generate stimulation signals (effectively operating as a drive electrode). During a stylus scan at touch sensor panel  600 , the stimulation signals can be injected by stylus  618  into the touch sensor panel  600  and can cause mutual capacitive coupling C 1  between the stylus  618  and the elongated electrodes  622  in the first layer (e.g., L 1 ) and/or capacitive coupling C 2  between the stylus  618  and the elongated electrodes  602  in the second layer (e.g., L 2 ). The capacitances C 1  and C 2  and/or the changes in capacitances C 1  and C 2  can be sensed at the location of a particular elongated electrode  622  and/or at the location of a particular elongated electrodes  602  by one or more touch sensing circuits for processing (e.g., as illustrated in  FIG.  4   ). In some examples, during the stylus scan, stimulation signals are not applied to elongated electrodes  622  and/or  602  apart from signals generated by the active stylus  618 ; rather, elongated electrodes  602  and/or touch node electrodes  606  are coupled to sense circuitry  414  in  FIG.  4    for sensing stylus  618 . 
       FIG.  6 D  illustrates the operation of touch sensor panel  600  to detect hover (proximity), touch, and/or force of an object (e.g., a finger) according to examples of the disclosure. For example, touch node electrodes  606  in the third layer (e.g., L 3 ) of the touch sensor panel  600  can be operated as self-capacitance touch node electrodes (e.g., as described above with reference to  FIG.  3   ) in a self-capacitance mode. While in this self-capacitance mode, capacitance coupling H sc  (e.g., hovering event) and/or T sc  (e.g., touch event) can occur between object  620  (e.g., finger) and self-capacitance touch node electrode  606 . This capacitance coupling (e.g., H sc  and/or T sc ) at the location of the particular touch node electrode  606  can be detected to indicate a touch or proximity event (e.g., as described above with reference to  FIG.  3   ). Touch sensor panel  600  can also be operated in a mutual capacitance mode. For example, elongated electrodes  622  in the first layer (e.g., L 1 ) of the touch sensor panel  600  can be operated as sense/drive electrodes (e.g., by coupling elongated electrodes  622  to sensing circuitry  414  of  FIG.  4   ) and elongated electrodes  602  in the second layer (e.g., L 2 ) of the touch sensor panel  600  can be operated as drive/sense electrodes (e.g., by coupling elongated electrodes  602  to stimulation signal  406  of  FIG.  4   ) in the mutual capacitance mode (e.g., as described above with reference to  FIG.  4   ). This configuration can cause mutual capacitive coupling T mc  between elongated electrodes  622  and elongated electrodes  602 . When a finger or object  620  approaches the touch node created by an intersection of an elongated electrode  622  and an elongated electrode  602 , mutual capacitance T mc  can be altered. This change in mutual capacitance T mc  at the location of the intersection of a particular elongated electrode  622  and a particular elongated electrode  602  can be detected to indicate a touch or proximity at the location of the touch node (e.g., as described above with reference to  FIG.  4   ). In some examples, elongated electrodes  622  in the first layer (e.g., L 1 ) of the touch sensor panel  600  can be operated as sense/drive electrodes and the touch node electrodes  606  in the third layer (e.g., L 3 ) of the touch sensor panel  600  can be operated as drive/sense electrodes (e.g., as groups of rows or columns) (e.g., as described above with reference to  FIG.  4   ). For example, a row of touch node electrodes  606  can be stimulated by a stimulation signal (e.g., an AC voltage signal). This stimulation signal can be capacitively coupled to elongated electrode  622  through mutual capacitance F mc  between the row of touch node electrodes  606  (e.g., drive electrode) and the elongated electrode  622  (e.g., sense electrode). When a finger or object  620  approaches the touch node created by the intersections of the row of touch node electrodes  606  (e.g., drive electrode) and elongated electrode  622 , mutual capacitance F mc  can be altered. This change in mutual capacitance F mc  at the location of the intersection of a particular touch node electrode(s)  606  and a particular elongated electrode  622  can be detected to indicate a touch or proximity event at the location of the touch node (e.g. as described above with reference to  FIG.  4   ). Moreover, when a pressure compliant or compressive material (e.g., a pressure sensitive adhesive (PSA), silicone, or any other material that compresses with pressure) is disposed between the second layer L 2  and the third layer L 3 , the distance between elongated electrode  622  and touch node electrodes  606  can change, causing mutual capacitance F mc  to change (e.g., as described above with reference to  FIG.  6 B ). This change in mutual capacitance F mc  at the location of the intersection of a particular elongated electrode  622  and a particular touch node electrode(s)  606  can be detected to indicate a force event at the location of the touch node. Additionally or alternatively when a pressure compliant or compressive material (e.g., a pressure sensitive adhesive (PSA), silicone, or any other material that compresses with pressure) is disposed between the third layer L 3  and the fourth layer L 4 , the distance between touch node electrodes  606  and conductive material  610  can change, causing mutual capacitance F mc  to change (e.g., as described above with reference to  FIG.  6 B ). 
       FIGS.  6 E- 6 K  illustrate exemplary tables describing different modes of operation for exemplary touch sensor panel configurations with four layers of electrodes according to examples of the disclosure. Specifically, the table illustrated in  FIG.  6 E  shows the different modes in which touch sensor panel  600  can be operated. For example,  FIG.  6 E  shows that touch sensor panel  600  can be used for stylus sensing S (e.g., as described above with reference to  FIG.  6 C ), touch/hover sensing in a self-capacitance configuration SC (e.g., as described above with reference to  FIG.  6 D ), touch sensing in a mutual capacitance configuration MC 1 -MC 8  (e.g., as described above with reference to  FIG.  6 D ), and force sensing F 1 -F 6  (e.g., as described above with reference to  FIG.  6 D ). For example, the table in  FIG.  6 E  illustrates that stylus sensing mode S can be performed by operating the elongated electrodes  622  in the first layer (e.g., L 1 ) and elongated electrodes  602  in the second layer (e.g., L 2 ) of touch sensor panel  600  as sense electrodes (e.g., by coupling elongated electrodes  602  and  622  to sensing circuitry  414  in  FIG.  4   ), and operating the conductive material  610  in the fourth layer (e.g., L 4 ) as a guard electrode (e.g., by operating the conductive material  610  at a reference voltage as previously described). In some examples, the touch node electrodes in the third layer (e.g., L 3 ) of the touch sensor panel can be operated as self-capacitance touch node electrodes (e.g., as described above with reference to  FIG.  3   ), sense lines/electrodes (e.g., as described above with reference to  FIG.  4   ), drive lines/electrodes (e.g., as described above with reference to  FIG.  4   ), or can be tied to ground, or left floating during the stylus sensing mode S. 
     In another example, the table in  FIG.  6 E  illustrates that touch/hover sensing mode SC can be performed by operating the touch node electrodes  606  in the third layer (e.g., L 3 ) of touch sensor panel  600  as self-capacitance touch node electrodes (e.g., as described above with reference to  FIG.  3   ) and operating the elongated electrodes  622  in the first layer (e.g., L 1 ), the elongated electrodes  602  in the second layer (e.g., L 2 ), and the conductive material disposed on the fourth layer (e.g., L 4 ) of the touch sensor panel  600  as a guard electrodes. 
     In another example, the table in  FIG.  6 E  illustrates that touch sensing modes MC 1 / 2  can be performed by operating elongated electrodes  622  in the first layer (e.g., L 1 ) of touch sensor panel  600  as sense/drive electrodes (e.g., coupling elongated electrodes  622  to sensing circuitry  414  of  FIG.  4    in mode MC 1  and coupling elongated electrodes  622  to stimulation signal  406  of  FIG.  4    in mode MC 2 ), operating elongated electrodes  602  in the second layer (e.g., L 2 ) of touch sensor panel  600  as drive/sense electrodes (e.g., coupling elongated electrodes  602  to stimulation signal  406  of  FIG.  4    in mode MC 1  and coupling elongated electrodes  602  to sensing circuitry  414  of  FIG.  4    in mode MC 2 ), and operating the conductive material  610  in the fourth layer (e.g., L 4 ) as a guard electrode (e.g., by operating the conductive material  610  at a reference voltage as previously described). In some examples, the touch node electrodes  606  in the third layer (e.g., L 3 ) of the touch sensor panel  600  can be operated as self-capacitance touch node electrodes (e.g., as described above with reference to  FIG.  3   ), sense lines/electrodes (e.g., as described above with reference to  FIG.  4   ), drive lines/electrodes (e.g., as described above with reference to  FIG.  4   ), or guard electrodes (e.g., by operating the touch node electrodes  606  at a reference voltage as previously described), or can be tied to ground, or left floating during the touch sensing modes MC 1 / 2 . In another example, the table in  FIG.  6 E  illustrates that touch sensing modes MC 3 / 4  can be performed by operating elongated electrodes  602  in the second layer (e.g., L 2 ) of touch sensor panel  600  as sense/drive electrodes (e.g., coupling elongated electrodes  602  to sensing circuitry  414  of  FIG.  4    in mode MC 3  and coupling elongated electrodes  602  to stimulation signal  406  of  FIG.  4    in mode MC 4 ), operating touch node electrodes  606  in the third layer (e.g., L 3 ) of touch sensor panel  600  as drive/sense electrodes (e.g., groups of touch node electrodes forming rows or columns) (e.g., coupling elongated electrodes  606  to stimulation signal  406  of  FIG.  4    in mode MC 3  and coupling touch node electrodes  606  to sensing circuitry  414  of  FIG.  4    in mode MC 4 ), and operating the conductive material  610  in the fourth layer (e.g., L 4 ) as a guard electrode (e.g., by operating the conductive material  610  at a reference voltage as previously described). In some examples, the elongated electrodes  622  in the first layer (e.g., L 1 ) of the touch sensor panel  600  can be operated as self-capacitance touch node electrodes (e.g., as described above with reference to  FIG.  3   ), sense electrodes (e.g., as described above with reference to  FIG.  4   ), drive electrodes (e.g., as described above with reference to  FIG.  4   ), or guard, or can be tied to ground, or left floating during the touch sensing modes MC 3 / 4 . In another example, the table in  FIG.  6 E  illustrates that touch sensing modes MC 5 / 6  can be performed by operating elongated electrodes  622  in the first layer (e.g., L 1 ) of touch sensor panel  600  as sense/drive electrodes (e.g., coupling elongated electrodes  622  to sensing circuitry  414  of  FIG.  4    in mode MC 5  and coupling elongated electrodes  622  to stimulation signal  406  of  FIG.  4    in mode MC 6 ), operating touch node electrodes  606  in the third layer (e.g., L 3 ) of touch sensor panel  600  as drive/sense electrodes (e.g., groups of touch node electrodes forming rows or columns) (e.g., coupling touch node electrodes  606  to stimulation signal  406  of  FIG.  4    in mode MC 5  and coupling touch node electrodes  606  to sensing circuitry  414  of  FIG.  4    in mode MC 6 ), and operating the conductive material  610  in the fourth layer (e.g., L 4 ) as a guard electrode (e.g., by operating the conductive material  610  at a reference voltage as previously described). In some examples, the elongated electrodes  602  in the second layer (e.g., L 2 ) of the touch sensor panel  600  can be operated as self-capacitance touch node electrodes, sense electrodes, drive electrodes, or guard, or can be tied to ground, or left floating during the touch sensing modes MC 5 / 6 . In another example, the table in  FIG.  6 E  illustrates that touch sensing modes MC 7 / 8  can be performed by operating elongated electrodes  622  in the first layer (e.g., L 1 ) of touch sensor panel  600  as sense/drive electrodes (e.g., coupling elongated electrodes  622  to sensing circuitry  414  of  FIG.  4    in mode MC 7  and coupling elongated electrodes  622  to stimulation signal  406  of  FIG.  4    in mode MC 8 ) and operating elongated electrodes  602  in the second layer (e.g., L 2 ) of touch sensor panel  600  as drive/sense electrodes (e.g., coupling elongated electrodes  602  to stimulation signal  406  of  FIG.  4    in mode MC 7  and coupling elongated electrodes  602  to sensing circuitry  414  of  FIG.  4    in mode MC 8 ). In some examples, the touch node electrodes  606  in the third layer (e.g., L 3 ) of the touch sensor panel  600  can be operated as self-capacitance touch node electrodes (e.g., as described above with reference to  FIG.  3   ), sense lines/electrodes (e.g., as described above with reference to  FIG.  4   ), drive lines/electrodes (e.g., as described above with reference to  FIG.  4   ), guard electrodes (e.g., by operating the touch node electrodes  606  at a reference voltage as previously described), or can be tied to ground, or left floating during the touch sensing modes MC 7 / 8 . In some examples, the conductive material  610  in the fourth layer (e.g., L 4 ) of the touch sensor panel  600  can be operated as a self-capacitance touch node electrode (e.g., as described above with reference to  FIG.  3   ), sense electrode (e.g., as described above with reference to  FIG.  4   ), drive electrode (e.g., as described above with reference to  FIG.  4   ), guard electrode (e.g., by operating the conductive material  610  at a reference voltage as previously described), or can be tied to ground, or left floating during the touch sensing modes MC 7 / 8 . 
     In another example, the table in  FIG.  6 E  illustrates that force sensing modes F 1 / 2  can be performed by operating elongated electrodes  622  in the first layer (e.g., L 1 ) of touch sensor panel  600  as sense/drive electrodes (e.g., coupling elongated electrodes  622  to sensing circuitry  414  of  FIG.  4    in mode F 1  and coupling elongated electrodes  622  to stimulation signal  406  of  FIG.  4    in mode F 2 ), operating groups of touch node electrodes  606  (e.g., groups of rows or columns) in the third layer (e.g., L 3 ) of touch sensor panel  600  as a drive/sense electrodes (e.g., coupling touch node electrodes  606  to stimulation signal  406  of  FIG.  4    in mode F 1  and coupling touch node electrodes  606  to sensing circuitry  414  of  FIG.  4    in mode F 2 ), and operating the conductive material  610  in the fourth layer (e.g., L 4 ) as a guard electrode (e.g., by operating the conductive material  610  at a reference voltage as previously described). In some examples, elongated electrodes  602  in the second layer (e.g., L 2 ) of touch sensor panel  600  can be operated as sense electrodes (e.g., as described above with reference to  FIG.  4   ), drive electrodes (e.g., as described above with reference to  FIG.  4   ), self-capacitance touch node electrodes (e.g., as described above with reference to  FIG.  3   ), or guard, or can be tied to ground, or left floating during the force sensing modes F 1 / 2 . In another example, the table in  FIG.  6 E  illustrates that force sensing modes F 3 / 4  can be performed by operating elongated electrodes  602  in the second layer (e.g., L 2 ) of touch sensor panel  600  as sense/drive electrodes (e.g., coupling elongated electrodes  602  to sensing circuitry  414  of  FIG.  4    in mode F 3  and coupling elongated electrodes  602  to stimulation signal  406  of  FIG.  4    in mode F 4 ), operating groups of touch node electrodes  606  (e.g., groups of rows or columns) in the third layer (e.g., L 3 ) of touch sensor panel  600  as a drive/sense electrodes (e.g., coupling touch node electrodes  606  to stimulation signal  406  of  FIG.  4    in mode F 3  and coupling touch node electrodes  606  to sensing circuitry  414  of  FIG.  4    in mode F 4 ), and operating the conductive material  610  in the fourth layer (e.g., L 4 ) as a guard electrode (e.g., by operating the conductive material  610  at a reference voltage as previously described). In some examples, elongated electrodes  622  in the first layer (e.g., L 1 ) of touch sensor panel  600  can be operated as sense electrodes (e.g., as described above with reference to  FIG.  4   ), drive electrodes (e.g., as described above with reference to  FIG.  4   ), self-capacitance touch node electrodes (e.g., as described above with reference to  FIG.  3   ), or guard, or can be tied to ground, or left floating during the force sensing modes F 3 / 4 . In another example, the table in  FIG.  6 E  illustrates that force sensing modes F 5 / 6  can be performed by operating touch node electrodes  606  in the third layer (e.g., L 3 ) of touch sensor panel  600  as sense/drive electrodes (e.g., groups of rows or columns) (e.g., coupling touch node electrodes  606  to sensing circuitry  414  of  FIG.  4    in mode F 5  and coupling touch node electrodes  606  to stimulation signal  406  of  FIG.  4    in mode F 6 ), and operating the conductive material  610  in the fourth layer (e.g., L 4 ) of touch sensor panel  600  as a drive/sense layer (e.g., coupling conductive material  610  to stimulation signal  406  of  FIG.  4    in mode F 4  and coupling conductive material  610  to sensing circuitry  414  of  FIG.  4    in mode F 5 ) (e.g., as described above with reference to  FIG.  6 D ). In some examples, elongated electrodes  622  in the first layer (e.g., L 1 ) and elongated electrodes  602  of touch sensor panel  600  can be operated as sense electrodes (e.g., as described above with reference to  FIG.  4   ), drive electrodes (e.g., as described above with reference to  FIG.  4   ), self-capacitance touch node electrodes (e.g., as described above with reference to  FIG.  3   ), or guard, or can be tied to ground, or left floating during the force sensing modes F 5 / 6 . 
       FIG.  6 F  illustrates a table showing additional details about stylus sensing mode S that can be performed using the touch sensor panel of the disclosure. For example,  FIG.  6 F  illustrates that stylus sensing mode S-A can be performed by operating both the elongated electrodes  622  in the first layer (e.g., L 1 ) and the elongated electrodes  602  in the second layer (e.g., L 2 ) of touch sensor panel  600  as sense electrodes (e.g., as described above with reference to  FIG.  4   ), operating at least one of the touch node electrode  606  in the third layer (e.g., L 3 ) of touch sensor panel  600  as sense line(s)/electrode(s) (e.g., as described above with reference to  FIG.  4   ) while coupling the remaining touch node electrodes  606  to a voltage source (e.g., operate them as guard) and/or ground, and operating the conductive material  610  in the fourth layer (e.g., L 4 ) of the touch sensor panel  600  as a guard electrode (e.g., by operating the conductive material  610  at a reference voltage as previously described). It should be understood that the electrodes operating as sense electrodes need not be sensed at the same time (e.g., can be sensed sequentially). In another example,  FIG.  6 F  illustrates that stylus sensing mode S-B can be performed by operating both the elongated electrodes  622  in the first layer (e.g., L 1 ) and the elongated electrodes  602  in the second layer (e.g., L 2 ) of touch sensor panel  600  as sense electrodes (e.g., as described above with reference to  FIG.  4   ), operating at least one row/column of touch node electrodes  606  (e.g., grouping touch node electrodes to form a row or a column) in the third layer (e.g., L 3 ) of touch sensor panel  600  as sense electrode(s) (e.g., as described above with reference to  FIG.  4   ) while coupling the remaining touch node electrodes  606  to a voltage source (e.g., operate them as guard) and/or ground, and operating the conductive material  610  in the fourth layer (e.g., L 4 ) of the touch sensor panel  600  as a guard electrode (e.g., by operating the conductive material  610  at a reference voltage as previously described). It should be understood that the row(s)/column(s) of touch node electrodes  606  operating as sense electrodes need not be sensed at the same time (e.g., can be sensed sequentially). In another example,  FIG.  6 F  illustrates that stylus sensing mode S-C can be performed by operating both the elongated electrodes  622  in the first layer (e.g., L 1 ) and the elongated electrodes  602  in the second layer (e.g., L 2 ) of touch sensor panel  600  as sense electrodes (e.g., as described above with reference to  FIG.  4   ), operating all rows/columns of touch node electrodes  606  (e.g., grouping touch node electrodes to form rows or columns) in the third layer (e.g., L 3 ) of touch sensor panel  600  as sense electrodes (e.g., as described above with reference to  FIG.  4   ), and operating the conductive material  610  in the fourth layer (e.g., L 4 ) as a guard layer (e.g., by operating the conductive material  610  at a reference voltage as previously described). In another example,  FIG.  6 F  illustrates that stylus sensing mode S-D can be performed by operating both the elongated electrodes  622  in the first layer (e.g., L 1 ) and the elongated electrodes  602  in the second layer (e.g., L 2 ) of touch sensor panel  600  as sense electrodes (e.g., by operating the conductive material  610  at a reference voltage as previously described), and operating the touch node electrodes  606  in the third layer (e.g., L 3 ) of touch sensor panel  600  and the conductive material  610  in the fourth layer (e.g., L 4 ) as a guard electrodes (e.g., by operating the touch node electrodes  606  and conductive material  610  at a reference voltage as previously described). 
       FIG.  6 G  illustrates a table showing additional touch panel configurations in which touch/hover sensing mode SC can be performed. For example,  FIG.  6 G  illustrates that touch/hover sensing mode SC-A can be performed by operating all of the touch node electrodes  606  in the third layer (e.g., L 3 ) of touch sensor panel  600  as self-capacitance touch node electrodes (e.g., as described above with reference to  FIG.  3   ) and operating the elongated electrodes  622  in the first layer (e.g., L 1 ), the elongated electrodes  602  in the second layer (e.g., L 2 ), and the conductive material  610  disposed on the fourth layer (e.g., L 4 ) of the touch sensor panel  600  as guard (e.g., by operating the elongated electrodes  602  and conductive material  610  at a reference voltage as previously described). In another example,  FIG.  6 G  illustrates that touch/hover sensing mode SC-B can be performed by operating a subset of the touch node electrodes  606  (e.g., a group, a row, a column, etc.) in the third layer (e.g., L 3 ) of touch sensor panel  600  as self-capacitance touch node electrodes (e.g., as described above with reference to  FIG.  3   ) while coupling the remaining touch node electrodes  606  in the third layer (e.g., L 3 ) of touch sensor panel  600  to a voltage source (e.g., operate them as guard), and operating the elongated electrodes  622  in the first layer (e.g., L 1 ), the elongated electrodes  602  in the second layer (e.g., L 2 ), and the conductive material disposed on the fourth layer (e.g., L 4 ) of the touch sensor panel  600  as guard (e.g., by operating elongated electrodes  622 , elongated electrodes  602 , and conductive material  610  at a reference voltage as previously described). For example, in a 3×3 touch node electrode configuration, the subset of the touch node electrodes  606  operated as self-capacitance touch node electrodes can be the first row of the 3×3 touch node electrode configuration and the remaining touch node electrodes  606  in the second and third rows of the 3×3 touch node electrode configuration can be coupled to a voltage source (e.g., operated as guard). In another example,  FIG.  6 G  illustrates that touch/hover sensing mode SC-C can be performed by operating a subset of the touch node electrodes  606  (e.g., a group, a row, a column, etc.) in the third layer (e.g., L 3 ) of touch sensor panel  600  as self-capacitance touch node electrodes (e.g., as described above with reference to  FIG.  3   ), coupling the remaining touch node electrodes  606  in the third layer (e.g., L 3 ) of touch sensor panel  600  to ground, and operating the elongated electrodes  622  in the first layer (e.g., L 1 ), the elongated electrodes  602  in the second layer (e.g., L 2 ), and the conductive material disposed on the fourth layer (e.g., L 4 ) of the touch sensor panel  600  as guard. For example, in a 3×3 touch node electrode configuration, the subset of the touch node electrodes  606  operated as self-capacitance touch node electrodes can be the second row of the 3×3 touch node electrode configuration and the remaining touch node electrodes  606  in the first and third rows of the 3×3 touch node electrode configuration can be coupled to ground. In another example,  FIG.  6 G  illustrates that touch/hover sensing mode SC-D can be performed by operating a first subset of touch node electrodes  606  (e.g., a group, a row, a column, etc.) in the third layer (e.g., L 3 ) of touch sensor panel  600  as self-capacitance touch node electrodes (e.g., as described above with reference to  FIG.  3   ), operating a second subset of touch node electrodes  606  (e.g., a group, a row, a column, etc.) in the third layer (e.g., L 3 ) of touch sensor panel  600  as guards, tying the remaining touch node electrodes  606  in the third layer (e.g., L 3 ) of touch sensor panel  600  to ground, and operating the elongated electrodes  622  in the first layer (e.g., L 1 ), the elongated electrodes  602  in the second layer (e.g., L 2 ), and the conductive material  610  disposed on the fourth layer (e.g., L 4 ) of the touch sensor panel  600  as guard (e.g., by operating elongated electrodes  622 , elongated electrodes  602 , and conductive material  610  at a reference voltage as previously described). For example, in a 3×3 touch node electrode configuration, the first row of touch node electrodes  606  in the 3×3 touch node electrode configuration can be operated as self-capacitance touch node electrodes, the second row of touch node electrodes  606  in the 3×3 touch node electrode configuration can be coupled to a voltage source (e.g., operated as guard), and the third row of touch node electrodes  606  in the 3×3 touch node electrode configuration can be coupled to ground. 
       FIG.  6 H  illustrates a table showing additional details about touch sensing mode MC 3  that can be performed using the touch sensor panel of the disclosure. For example,  FIG.  6 H  illustrates that touch sensing mode MC 3 -A can be performed by operating elongated electrodes  602  in the second layer (e.g., L 2 ) of touch sensor panel  600  as sense electrodes, operating at least one touch node electrode  606  in the third layer (e.g., L 3 ) of touch sensor panel  600  as drive line(s)/electrode(s) (e.g., as described above with reference to  FIG.  4   ) while coupling the remaining touch node electrodes  606  to a voltage source (e.g., operate them as guard) and/or ground, and operating the conductive material  610  in the fourth layer (e.g., L 4 ) as a guard layer (e.g., as described above with reference to  FIGS.  4  and  6 D ). In some examples, elongated electrodes  622  in the first layer (e.g., L 1 ) of touch sensor panel  600  can be operated as sense electrodes, drive electrodes, self-capacitance touch node electrodes, or guard, or can be tied to ground, or left floating during the touch sensing mode MC 3 -A. In another example,  FIG.  6 H  illustrates that touch sensing mode MC 3 -B can be performed by operating elongated electrodes  602  in the second layer (e.g., L 2 ) of touch sensor panel  600  as sense electrodes (e.g., as described above with reference to  FIG.  4   ), operating at least one row or column of touch node electrodes  606  (e.g., by grouping touch node electrodes to form rows or columns) in the third layer (e.g., L 3 ) of touch sensor panel  600  as drive line(s)/electrode(s) (e.g., as described above with reference to  FIG.  4   ) while coupling the remaining touch node electrodes  606  to a voltage source (e.g., operate them as guard) and/or ground, and operating the conductive material  610  in the fourth layer (e.g., L 4 ) as a guard layer (e.g., as described above with reference to  FIGS.  4  and  6 D ). For example, in a 3×3 touch node electrode configuration, the first row of touch node electrodes  606  in the 3×3 touch node electrode configuration can be operated as a drive electrode and the remaining touch node electrodes  606  in the second and third rows of the 3×3 touch node electrode configuration can be coupled to a voltage source (e.g., operated as guard) and/or ground. In some examples, elongated electrodes  622  in the first layer (e.g., L 1 ) of touch sensor panel  600  can be operated as sense electrodes, drive electrodes, self-capacitance touch node electrodes (e.g., as described above with reference to  FIGS.  3 - 4   ), or guard, or can be tied to ground, or left floating during the touch sensing mode MC 3 -B. In another example,  FIG.  6 H  illustrates that touch sensing mode MC 3 -C can be performed by operating elongated electrodes  602  in the second layer (e.g., L 2 ) of touch sensor panel  600  as sense electrodes, operating all rows or columns of touch node electrodes  606  (e.g., by grouping touch node electrodes to form rows or columns) in the third layer (e.g., L 3 ) of touch sensor panel  600  as a drive electrodes (e.g., as described above with reference to  FIG.  4   ), and operating the conductive material  610  in the fourth layer (e.g., L 4 ) as a guard layer (e.g., as described above with reference to  FIGS.  4  and  6 D ). In some examples, elongated electrodes  622  in the first layer (e.g., L 1 ) of touch sensor panel  600  can be operated as sense electrodes, drive electrodes, self-capacitance touch node electrodes (e.g., as described above with reference to  FIGS.  3 - 4   ), or guard, or can be tied to ground, or left floating during the touch sensing mode MC 3 -C. 
       FIG.  6 I  illustrates a table showing additional details about touch sensing mode MC 4  that can be performed using the touch sensor panel of the disclosure. For example,  FIG.  6 I  illustrates that touch sensing mode MC 4 -A can be performed operating elongated electrodes  602  in the second layer (e.g., L 2 ) of touch sensor panel  600  as drive electrodes, operating at least one touch node electrode  606  in the third layer (e.g., L 3 ) of touch sensor panel  600  as a sense line/electrode (e.g., as described above with reference to  FIG.  4   ) while coupling the remaining touch node electrodes  606  to a voltage source (e.g., operate them as guard) and/or ground, and operating the conductive material  610  in the fourth layer (e.g., L 4 ) as a guard electrode (e.g., by operating the conductive material  610  at a reference voltage as previously described). In some examples, elongated electrodes  622  in the first layer (e.g., L 1 ) of touch sensor panel  600  can be operated as sense electrodes, drive electrodes, self-capacitance touch node electrodes (e.g., as described above with reference to  FIGS.  3 - 4   ), or guard, or can be tied to ground, or left floating during the touch sensing mode MC 4 -A. In another example,  FIG.  6 I  illustrates that touch sensing mode MC 4 -B can be performed by operating elongated electrodes  602  in the second layer (e.g., L 2 ) of touch sensor panel  600  as drive electrodes (e.g., as described above with reference to  FIG.  4   ), operating at least one row or column of touch node electrodes  606  (e.g., by grouping touch node electrodes to form rows or columns) in the third layer (e.g., L 3 ) of touch sensor panel  600  as sense line(s)/electrode(s) (e.g., as described above with reference to  FIG.  4   ) while coupling the remaining touch node electrodes  606  to a voltage source (e.g., operate them as guard) and/or ground, and operating the conductive material  610  in the fourth layer (e.g., L 4 ) as a guard electrode (e.g., by operating the conductive material  610  at a reference voltage as previously described). In some examples, elongated electrodes  622  in the first layer (e.g., L 1 ) of touch sensor panel  600  can be operated as sense electrodes, drive electrodes, self-capacitance touch node electrodes (e.g., as described above with reference to  FIGS.  3 - 4   ), or guard, or can be tied to ground, or left floating during the touch sensing mode MC 4 -B. For example, in a 3×3 touch node electrode configuration, the first row of touch node electrodes  606  in the 3×3 touch node electrode configuration can be operated as a sense electrode (e.g., as described above with reference to  FIG.  4   ) and the remaining touch node electrodes  606  in the second and third rows of the 3×3 touch node electrode configuration can be coupled to a voltage source (e.g., operated as guard) and/or ground. In another example,  FIG.  6 I  illustrates that touch sensing mode MC 4 -C can be performed by operating elongated electrodes  602  in the second layer (e.g., L 2 ) of touch sensor panel  600  as drive electrodes (e.g., as described above with reference to  FIG.  4   ), operating all rows or columns of touch node electrodes  606  (e.g., by grouping touch node electrodes to form rows or columns) in the third layer (e.g., L 3 ) of touch sensor panel  600  as a sense electrodes (e.g., as described above with reference to  FIG.  4   ), and operating the conductive material  610  in the fourth layer (e.g., L 4 ) as a guard electrode (e.g., by operating the conductive material  610  at a reference voltage as previously described). In some examples, elongated electrodes  622  in the first layer (e.g., L 1 ) of touch sensor panel  600  can be operated as sense electrodes, drive electrodes, self-capacitance touch node electrodes (e.g., as described above with reference to  FIGS.  3 - 4   ), or guard, or can be tied to ground, or left floating during the touch sensing mode MC 4 -C. 
       FIG.  6 J  illustrates a table showing additional details about touch sensing mode MC 5  can be performed using the touch sensor of the disclosure. For example,  FIG.  6 J  illustrates that touch sensing mode MC 5 -A can be performed by operating elongated electrodes  622  in the first layer (e.g., L 1 ) of touch sensor panel  600  as sense electrodes (e.g., as described above with reference to  FIG.  4   ), operating at least one touch node electrode  606  in the third layer (e.g., L 3 ) of touch sensor panel  600  as a drive line(s)/electrode(s) (e.g., as described above with reference to  FIG.  4   ) while coupling the remaining touch node electrodes  606  to a voltage source (e.g., operate them as guard) and/or ground, and operating the conductive material  610  in the fourth layer (e.g., L 4 ) as a guard electrode (e.g., by operating the conductive material  610  at a reference voltage as previously described). In some examples, elongated electrodes  602  in the second layer (e.g., L 2 ) of touch sensor panel  600  can be operated as sense electrodes, drive electrodes, self-capacitance touch node electrodes (e.g., as described above with reference to  FIGS.  3 - 4   ), or guard, or can be tied to ground, or left floating during the touch sensing mode MC 5 -A. In another example,  FIG.  6 J  illustrates that touch sensing mode MC 5 -B can be performed by operating elongated electrodes  622  in the first layer (e.g., L 1 ) of touch sensor panel  600  as sense electrodes (e.g., as described above with reference to  FIG.  4   ), operating at least one row or column of touch node electrodes  606  (e.g., by grouping touch node electrodes to form rows or columns) in the third layer (e.g., L 3 ) of touch sensor panel  600  as drive line(s)/electrode(s) (e.g., as described above with reference to  FIG.  4   ) while coupling the remaining touch node electrodes  606  to a voltage source (e.g., operate them as guard) and/or ground, and operating the conductive material  610  in the fourth layer (e.g., L 4 ) as a guard electrode (e.g., by operating the conductive material  610  at a reference voltage as previously described). In some examples, elongated electrodes  602  in the second layer (e.g., L 2 ) of touch sensor panel  600  can be operated as sense electrodes, drive electrodes, self-capacitance touch node electrodes (e.g., as described above with reference to  FIGS.  3 - 4   ), or guard, or can be tied to ground, or left floating during the touch sensing mode MC 5 -B. For example, in a 3×3 touch node electrode configuration, the first row of touch node electrodes  606  in the 3×3 touch node electrode configuration can be operated as a drive electrode and the remaining touch node electrodes  606  in the second and third rows of the 3×3 touch node electrode configuration can be coupled to a voltage source (e.g., operated as guard) and/or ground. In another example,  FIG.  6 J  illustrates that touch sensing mode MC 5 -C can be performed by operating elongated electrodes  622  in the first layer (e.g., L 1 ) of touch sensor panel  600  as sense electrodes, operating all rows or columns of touch node electrodes  606  (e.g., by grouping touch node electrodes to form rows or columns) in the third layer (e.g., L 3 ) of touch sensor panel  600  as a drive electrodes (e.g., as described above with reference to  FIG.  4   ), and operating the conductive material  610  in the fourth layer (e.g., L 4 ) as a guard layer (e.g., as described above with reference to  FIGS.  4  and  6 D ). In some examples, elongated electrodes  602  in the second layer (e.g., L 2 ) of touch sensor panel  600  can be operated as sense electrodes, drive electrodes, self-capacitance touch node electrodes (e.g., as described above with reference to  FIGS.  3 - 4   ), or guard, or can be tied to ground, or left floating during the touch sensing mode MC 5 -C. 
       FIG.  6 K  illustrates a table showing additional details about how touch sensing mode MC 6  can be performed using the touch sensor of the disclosure. For example,  FIG.  6 K  illustrates that touch sensing mode MC 6 -A can be performed operating elongated electrodes  622  in the first layer (e.g., L 1 ) of touch sensor panel  600  as drive electrodes (e.g., as described above with reference to  FIG.  4   ), operating at least one touch node electrode  606  in the third layer (e.g., L 3 ) of touch sensor panel  600  as a sense line/electrode (e.g., as described above with reference to  FIG.  4   ) while coupling the remaining touch node electrodes  606  to a voltage source (e.g., operate them as guard) and/or ground, and operating the conductive material  610  in the fourth layer (e.g., L 4 ) as a guard electrode (e.g., by operating the conductive material  610  at a reference voltage as previously described). In some examples, elongated electrodes  602  in the second layer (e.g., L 2 ) of touch sensor panel  600  can be operated as sense electrodes, drive electrodes, self-capacitance touch node electrodes (e.g., as described above with reference to  FIGS.  3 - 4   ), or guard, or can be tied to ground, or left floating during the touch sensing mode MC 6 -A. In another example,  FIG.  6 K  illustrates that touch sensing mode MC 6 -B can be performed by operating elongated electrodes  622  in the first layer (e.g., L 1 ) of touch sensor panel  600  as drive electrodes (e.g., as described above with reference to  FIG.  4   ), operating at least one row or column of touch node electrodes  606  (e.g., by grouping touch node electrodes to form rows or columns) in the third layer (e.g., L 3 ) of touch sensor panel  600  as sense line(s)/electrode(s) (e.g., as described above with reference to  FIG.  4   ) while coupling the remaining touch node electrodes  606  to a voltage source (e.g., operate them as guard) and/or ground, and operating the conductive material  610  in the fourth layer (e.g., L 4 ) as a guard electrode (e.g., by operating the conductive material  610  at a reference voltage as previously described). In some examples, elongated electrodes  602  in the second layer (e.g., L 2 ) of touch sensor panel  600  can be operated as sense electrodes, drive electrodes, self-capacitance touch node electrodes (e.g., as described above with reference to  FIGS.  3 - 4   ), or guard, or can be tied to ground, or left floating during the touch sensing mode MC 6 -B. For example, in a 3×3 touch node electrode configuration, the first row of touch node electrodes  606  in the 3×3 touch node electrode configuration can be operated as a sense electrode (e.g., as described above with reference to  FIG.  4   ) and the remaining touch node electrodes  606  in the second and third rows of the 3×3 touch node electrode configuration can be coupled to a voltage source (e.g., operated as guard) and/or ground. In another example,  FIG.  6 K  illustrates that touch sensing mode MC 6 -C can be performed by operating elongated electrodes  622  in the first layer (e.g., L 1 ) of touch sensor panel  600  as drive electrodes (e.g., as described above with reference to  FIG.  4   ), operating all rows or columns of touch node electrodes  606  (e.g., by grouping touch node electrodes to form rows or columns) in the third layer (e.g., L 3 ) of touch sensor panel  600  as a sense electrodes (e.g., as described above with reference to  FIG.  4   ), and operating the conductive material  610  in the fourth layer (e.g., L 4 ) as a guard electrode (e.g., by operating the conductive material  610  at a reference voltage as previously described). In some examples, elongated electrodes  602  in the second layer (e.g., L 2 ) of touch sensor panel  600  can be operated as sense electrodes, drive electrodes, self-capacitance touch node electrodes, or guard, or can be tied to ground, or left floating during the touch sensing mode MC 6 -C. 
       FIG.  7    illustrates an exemplary touch sensor panel configuration  700  with four layers of electrodes according to examples of the disclosure. Specifically,  FIG.  7    illustrates touch sensor panel configuration  700  that is similar to the touch sensor panel configuration  600 , as described with reference to  FIGS.  6 A- 6 K , with elongated electrodes  722 , elongated electrodes  702 , and touch node electrodes  706  in  FIG.  7    corresponding to electrodes  622 , elongated electrodes  602 , and touch node electrodes  606  in  FIG.  6   , respectively. Thus, the cross-section of touch sensor panel configuration  700  can be as illustrated in  FIG.  6 B , except for the lateral dimensions of touch node electrodes  706  and/or the placement of elongated electrodes  702  and  722  with respect to touch node electrodes  706 . In particular, the touch node electrodes  706  in  FIG.  7    can have a larger surface area than the touch node electrodes  606  in  FIG.  6    (in the example of  FIG.  7   , four times the area of touch node electrodes  606  in  FIG.  6   ). Moreover, the elongated electrodes  722  and  702  can be disposed within the regions of the touch sensor panel that are occupied by touch node electrodes  706  as illustrated in  FIG.  7   , and not simply at or near the edges or boundaries of touch node electrodes  706  as illustrated in  FIG.  6    (e.g., elongated electrodes  722  and  702  can be disposed over inner regions of touch node electrodes  706  as well as over boundary regions or regions between touch node electrodes  706 ). In some examples, touch node electrodes  706  in  FIG.  7    can have a surface area substantially similar to touch node electrodes  606  in  FIG.  6   , and touch sensor panel  700  can simply include additional elongated electrodes  722  and  702  that can be arranged across the regions of the touch sensor panel that are occupied by touch node electrodes  706  as illustrated in  FIG.  7    (e.g., elongated electrodes  722  and  702  can be disposed at a higher frequency/rate with respect to touch node electrodes  706  in touch sensor panel  700  than are elongated electrodes  622  and  602  in touch sensor panel  600 . For example, in  FIG.  6   , along a given dimension, the rate at which elongated electrodes  622  and  602  are disposed can be one for every touch node electrode  606 , whereas in  FIG.  7   , the rate at which elongated electrodes  722  and  702  are disposed can be two for every touch node electrode  706 ). The configuration of touch sensor panel  700  can allow the touch sensor panel to detect hover events in the z-axis at greater distances (e.g., utilizing self-capacitance sensing of touch node electrodes  706  in the circumstance in which touch node electrodes  706  are larger than touch node electrodes  606 ) and/or greater accuracy (e.g., utilizing a greater number of elongated electrodes  702  and  722  in the circumstance in which touch node electrodes  706  are the same size as touch node electrodes  606 ). Moreover, having touch node electrodes  706  with a larger surface area, and thus having fewer touch node electrodes  706  for a given touch sensor panel size, can reduce the number of traces in the third layer (e.g., L 3 ) of touch sensor panel  700  needed to couple those touch node electrodes  706  to sense circuitry (e.g., circuitry  314  in  FIG.  3    or circuitry  414  in  FIG.  4   ). It should be noted that touch sensor panel  700  can operate in any of the modes of operation, including the manners of operation, described above with reference to  FIGS.  6 A- 6 K . 
       FIG.  8    illustrates an exemplary timeline  800  of the modes of operation for exemplary touch sensor panel configurations according to examples of the disclosure. Specifically, timeline  800  shows stylus row sensing  802  being performed in which row(s) of electrodes (e.g., elongated electrodes  602  and/or groups of touch node electrodes  606 ) are sensed in a mutual capacitance sense mode to detect a stylus (e.g., as described above with reference to  FIGS.  6 C,  6 E, and  6 F ). Timeline  800  then shows stylus column sensing  804  is being performed in which column(s) of electrodes (e.g., elongated electrodes  622  and/or groups of touch node electrodes  606 ) are sensed in a mutual capacitance sense mode to detect a stylus (e.g., as described above with reference to  FIGS.  6 C,  6 E, and  6 F ). Finally, timeline  800  shows hover and touch sensing  806  being performed in which touch node electrodes are sensed in a self-capacitance mode to detect a hover and/or touch event (e.g., as described above with reference to  FIGS.  6 D,  6 E, and  6 G ). This pattern of stylus row sensing  802 , followed by stylus column sensing  804 , and followed by hover and touch sensing  806  can be repeated continuously as illustrated in  FIG.  8   . In some examples, stylus sensing  802  and  804  are combined and performed simultaneously. In some examples, the duration of stylus row sensing  802  and stylus column sensing  804  can be the same. In some examples, the duration of stylus row sensing  802  and stylus column sensing  804  can be different. In some examples, hover and touch sensing  806  is not performed if a stylus is detected. For example, if a stylus is detected in stylus row  802  and/or stylus column sensing  804 , stylus row  802  and stylus column sensing  804  can be repeated in an alternating fashion while skipping the hover and touch sensing mode  806 . In some examples, hover and touch sensing  806  may be performed in a mutual capacitance mode (e.g., as described above with reference to  FIGS.  6 D,  6 E, and  6 H- 6 K ). 
       FIG.  9 A  illustrates another exemplary timeline  900  of the modes of operation for exemplary touch sensor panel configurations according to examples of the disclosure. Specifically, timeline  900  shows hover and touch sensing  906  being performed in which touch node electrodes are sensed in a self-capacitance mode to detect a hover and/or touch event (e.g., as described above with reference to  FIGS.  5 D,  5 E,  5 G,  6 D,  6 E, and  6 G ). Timeline  900  also shows touch and force sensing  908  (e.g., as described above with reference to  FIGS.  5 D,  5 E,  5 G- 5 I,  6 D,  6 E, and  6 G- 6 K ) being performed after hover and touch sensing  906 . In some examples, touch and force sensing  908  is not performed when a hover or touch event is not detected (e.g., as described with reference to  FIG.  9 B  below), because it can be the case that if no hover/touch is detected, there cannot be a force to detect, either. In some examples, the durations of hover and touch sensing  906  and touch and force sensing  908  are the same. In some examples, the durations of hover and touch sensing  906  and touch and force sensing  908  are different. In some examples, touch sensing and force sensing can be performed simultaneously. For example, touch sensing mode MC 1  and force sensing mode F 6  can be performed at the same time (e.g., such that changes in mutual capacitance between the electrodes in L 1  and L 2  and between electrodes in L 3  and L 4  are detected as described above). 
       FIG.  9 B  illustrates an exemplary process  950  for switching between modes of operation of exemplary touch sensor panel configurations according to examples of the disclosure. Specifically, exemplary process  950  performs a scan for hover and/or touch events at step  960  (e.g., as described above with reference to  FIGS.  5 D,  5 E,  5 G,  6 D,  6 E , and  6 G). For example, process  950  can operate the touch sensor panel in the self capacitance mode SC as described above with reference to  FIG.  5 G or  6 G  to perform touch/hover sensing. At step  962 , process  650  determines whether a touch or hover event is detected. If a touch or hover event is not detected at step  962 , process  950  enters a sleep mode for a set period of time at step  964 . In some examples, the period of time (e.g., duration) of the sleep mode is duration of time the touch sensor panel would take performing a touch and/or force scan. In some examples, the period of time (e.g., duration) of the sleep mode is a fixed duration of time. Process  950  returns to step  960  upon completion of the sleep mode in step  964 . If a touch or hover event is detected at step  962 , process  950  performs a scan for a touch and/or force event (e.g., as described above with reference to  FIGS.  5 D,  5 E,  5 G,  5 I,  6 D,  6 E, and  6 G- 6 K ). For example, process  950  can operate the touch sensor panel in any of the mutual capacitance modes to perform touch sensing (e.g., as described with reference to modes MC 1 -MC 2  of  FIGS.  5 E and  5 H- 5 I , and modes MC 1 -MC 8  of  FIGS.  6 E and  6 H- 6 K ) and/or force sensing (e.g., as described with reference to modes F 1 -F 4  of  FIG.  5 E  and modes F 1 -F 6  of  FIG.  6 E ). Process  950  returns to step  960  upon completion of the touch and/or force scan in step  966 . 
       FIG.  10    illustrates an exemplary timeline of the modes of operation for exemplary touch sensor panel configurations according to examples of the disclosure. Specifically, timeline  1000  shows stylus row sensing  1002  being performed in which row(s) of electrodes are sensed in a mutual capacitance mode to detect a stylus (e.g., as described above with reference to  FIGS.  6 C,  6 E, and  6 F ). Timeline  1000  then shows stylus column sensing  1004  is being performed in which column(s) of electrodes are sensed in a mutual capacitance mode to detect a stylus (e.g., as described above with reference to  FIGS.  6 C,  6 E, and  6 F ). Next, timeline  1000  shows hover and touch sensing  1006  being performed in which touch node electrodes are sensed in a self-capacitance mode to detect a hover and/or touch event (e.g., as described above with reference to  FIGS.  6 D,  6 E, and  6 G ). Finally, timeline  1000  shows touch and/or force sensing  1008  being performed (e.g., as described above with reference to  FIGS.  6 D,  6 E, and  6 G- 6 K ). This pattern of stylus row sensing  1002 , followed by stylus column sensing  1004 , followed by hover and touch sensing  1006 , and followed by touch and/or force sensing  1008  can be repeated continuously as illustrated in  FIG.  10   . In some examples, stylus sensing  1002  and  1004  are combined and performed simultaneously. In some examples, the duration of stylus sensing  1002  and stylus sensing  1004  can be the same. In some examples, the duration of stylus row sensing  1002  and stylus column sensing  1004  can be different. In some examples, touch and/or force sensing  1008  is not performed when a hover or touch event is not detected (e.g., as described with reference to  FIG.  9 B  above), because it can be the case that if no hover/touch is detected, there cannot be a force to detect, either. Instead, the touch sensor panel enters a sleep mode (e.g., as described with reference to  FIG.  9 B  above) or simply performs the stylus row sensing  1002 , followed by stylus column sensing  1004 , and hover and/or touch sensing  1006  without performing the touch and/or force sensing  1008  (e.g., touch and/or force sensing  1008  is skipped if not hover or touch event is detected). 
     Thus, the examples of the disclosure provide various touch sensor panel configurations that allow for various electrodes to be used in hover, touch, force, and/or stylus sensing and/or guarding functions, which can improve the touch sensing performance of the system while reducing the number of electrodes and corresponding routing traces. 
     Therefore, according to the above, some examples of the disclosure are directed to a touch sensor panel comprising: a first layer including a plurality of electrodes of a first type, wherein the electrodes of the first type are coupled to respective traces, and the electrodes of the first type are configured to, during a first time period, operate as touch sensing electrodes; and a second layer including a plurality of electrodes of a second type overlapping with the respective traces of the electrodes of the first type, wherein the electrodes of the second type are configured to: during the first time period, operate as guard electrodes for the respective traces of the electrodes of the first type; and during a second time period, operate as touch sensing electrodes. Additionally or alternatively to one or more of the examples disclosed above, in some examples, the first type of electrodes are a different type of electrode than the second type of electrodes. Additionally or alternatively to one or more of the examples disclosed above, in some examples, the first type of electrodes are touch node electrodes; and the second type of electrodes are elongated electrodes. Additionally or alternatively to one or more of the examples disclosed above, in some examples, operating, during the first time period, the electrodes of the second type as the guard electrodes comprises driving the electrodes of the second type at a reference voltage. Additionally or alternatively to one or more of the examples disclosed above, in some examples, operating, during the first time period, the electrodes of the first type as the touch sensing electrodes comprises operating the electrodes of the first type as self-capacitance sensing electrodes. Additionally or alternatively to one or more of the examples disclosed above, in some examples, operating the electrodes of the second type as the touch sensing electrodes comprises operating the electrodes of the second type as mutual capacitance electrodes. Additionally or alternatively to one or more of the examples disclosed above, in some examples, a third layer including an electrode of a third type configured to, during the first and second time periods, operate as a guard electrode. Additionally or alternatively to one or more of the examples disclosed above, in some examples, the electrode of the third type is further configured to: during a third time period, operate as a force sensing electrode. Additionally or alternatively to one or more of the examples disclosed above, in some examples, the first type of electrodes are further configured to: during the third time period, operate as force sensing electrodes, wherein during the third time period, a force is determined based on the electrode of the third type and the electrodes of the first type. Additionally or alternatively to one or more of the examples disclosed above, in some examples, the second type of electrodes are further configured to: during the third time period, operate as force sensing electrodes, wherein during the third time period, a force is determined based on the electrode of the third type and the electrodes of the second type. Additionally or alternatively to one or more of the examples disclosed above, in some examples, a third layer including a plurality of electrodes of a third type, wherein the electrodes of the third type are configured to: during the first time period, operate as guard electrodes for the respective traces of the electrodes of the first type; and during the second time period, operate as touch sensing electrodes. Additionally or alternatively to one or more of the examples disclosed above, in some examples, the first type of electrodes are touch node electrodes; and the second and third types of electrodes are elongated electrodes. Additionally or alternatively to one or more of the examples disclosed above, in some examples, operating, during the first time period, the electrodes of the second and third types as the guard electrodes comprises driving the electrodes of the second and third types at a reference voltage. Additionally or alternatively to one or more of the examples disclosed above, in some examples, operating, during the first time period, the electrodes of the first type as the touch sensing electrodes comprises operating the electrodes of the first type as self-capacitance sensing electrodes. Additionally or alternatively to one or more of the examples disclosed above, in some examples, operating, during the second time period, the electrodes of the second type as the touch sensing electrodes comprises operating the electrodes of the second type as mutual capacitance electrodes with respect to the electrodes of the third type; and operating, during the second time period, the electrodes of the third type as the touch sensing electrodes comprises operating the electrodes of the third type as mutual capacitance electrodes with respect to the electrodes of the second type. Additionally or alternatively to one or more of the examples disclosed above, in some examples, operating, during the first time period, the electrodes of the first type as the touch sensing electrodes comprises operating the electrodes of the first type as self-capacitance sensing electrodes. Additionally or alternatively to one or more of the examples disclosed above, in some examples, the electrodes of the first type are further configured to: during a third time period, operate as mutual capacitance electrodes. Additionally or alternatively to one or more of the examples disclosed above, in some examples, the electrodes of the second type are further configured to: during the third time period, operate as mutual capacitance electrodes with respect to the electrodes of the first type. Additionally or alternatively to one or more of the examples disclosed above, in some examples, the electrodes of the third type are further configured to: during the third time period, operate as mutual capacitance electrodes with respect to the electrodes of the first type. Additionally or alternatively to one or more of the examples disclosed above, in some examples, operating the electrodes of the second type as the touch sensing electrodes comprises operating the electrodes of the second type as mutual capacitance electrodes with respect to the electrodes of the third type; and operating the electrodes of the third type as the touch sensing electrodes comprises operating the electrodes of the third type as mutual capacitance electrodes with respect to the electrodes of the second type. Additionally or alternatively to one or more of the examples disclosed above, in some examples, a fourth layer including an electrode of a fourth type configured to, during the first, second, and third time periods, operate as a guard electrode. Additionally or alternatively to one or more of the examples disclosed above, in some examples, the electrode of the fourth type is further configured to: during a fourth time period, operate as a force sensing electrode. Additionally or alternatively to one or more of the examples disclosed above, in some examples, operating the electrodes of the first type as mutual capacitance electrodes comprises operating the electrodes of the first type as force sensing electrodes, wherein during the fourth time period, a force is determined based on the electrode of the fourth type and the electrodes of the first type. Additionally or alternatively to one or more of the examples disclosed above, in some examples, the plurality of electrodes of the second type are arranged in rows along a horizontal axis, and include extensions along a vertical axis that overlap with the respective traces of the electrodes of the first type. 
     Some examples of the disclosure are directed to a method for operating a touch sensor panel comprising: a first layer including a plurality of electrodes of a first type, wherein the electrodes of the first type are configured to, during a first time period, operate as mutual capacitance drive electrodes; and a second layer including a plurality of electrodes of a second type overlapping with the electrodes of the first type, wherein the electrodes of the second type are configured to: during the first time period, operate as mutual capacitance sense electrodes; and during a second time period, operate as self-capacitance electrodes. Additionally or alternatively to one or more of the examples disclosed above, in some examples, the plurality of electrodes of the second type are arranged in rows along a horizontal axis, a given row of electrodes of the second type includes a plurality of individually addressable electrodes of the second type, during the first time period, the plurality of individually addressable electrodes of the second type in the given row are sensed with the same sense circuitry, and during the second time period, the plurality of individually addressable electrodes of the second type in the given row are sensed with different sense circuitry. Additionally or alternatively to one or more of the examples disclosed above, in some examples, the plurality of electrodes of the first type are arranged in columns along a vertical axis, a given column of electrodes of the first type includes a plurality of individually addressable electrodes of the first type, and during the first time period, the plurality of individually addressable electrodes of the first type in the given column are drive with the same drive signal. Additionally or alternatively to one or more of the examples disclosed above, in some examples, the plurality of electrodes of the first type and the plurality of electrodes of the second type are grouped to form a plurality of super nodes on the touch sensor panel, and each super node is individually operable to perform independent touch sensing operations. 
     Some examples of the disclosure are directed to a method for operating a touch sensor panel, the method comprising: operating a plurality of electrodes of a first type, during a first time period, as touch sensing electrodes, wherein the electrodes of the first type are in a first layer of the touch sensor panel and are coupled to respective traces; and operating a plurality of electrodes of a second type: during the first time period, as guard electrodes for the respective traces of the electrodes of the first type; and during a second time period, as touch sensing electrodes, wherein the electrodes of the second type are in a second layer of the touch sensor panel and overlap with the respective traces of the electrodes of the first type. 
     Some examples of the disclosure are directed to a non-transitory computer readable storage medium storing one or more programs, the one or more programs comprising instructions, which when executed by a processor, cause the processor to perform a method for operating a touch sensor panel comprising: operating a plurality of electrodes of a first type, during a first time period, as touch sensing electrodes, wherein the electrodes of the first type are in a first layer of the touch sensor panel and are coupled to respective traces; and operating a plurality of electrodes of a second type: during the first time period, as guard electrodes for the respective traces of the electrodes of the first type; and during a second time period, as touch sensing electrodes, wherein the electrodes of the second type are in a second layer of the touch sensor panel and overlap with the respective traces of the electrodes of the first type. 
     Although examples of this disclosure have been fully described with reference to the accompanying drawings, it is to be noted that various changes and modifications will become apparent to those skilled in the art. Such changes and modifications are to be understood as being included within the scope of examples of this disclosure as defined by the appended claims.

Metadata:
Filing Date: 20180928
Publication Date: 20230822
Grant Date: 20230822
Priority Date: 20170929
Inventors: KNABENSHUE, Brian H.
LIN, ALBERT
HU, JASON C.
SAUER, Christian M.
GRUNTHANER, MARTIN PAUL
Assignee: APPLE INC
CPC Classifications: [{"code": "G06F3/041662", "inventive": true, "first": true, "tree": "[]"}, {"code": "G06F3/0442", "inventive": true, "first": false, "tree": "[]"}, {"code": "G06F3/0445", "inventive": true, "first": false, "tree": "[]"}, {"code": "G06F3/0446", "inventive": true, "first": false, "tree": "[]"}, {"code": "G06F3/0448", "inventive": true, "first": false, "tree": "[]"}, {"code": "G06F3/04162", "inventive": true, "first": false, "tree": "[]"}, {"code": "G06F3/04164", "inventive": false, "first": false, "tree": "[]"}, {"code": "G06F2203/04105", "inventive": false, "first": false, "tree": "[]"}, {"code": "G06F2203/04106", "inventive": false, "first": false, "tree": "[]"}, {"code": "G06F2203/04107", "inventive": false, "first": false, "tree": "[]"}, {"code": "G06F2203/04108", "inventive": false, "first": false, "tree": "[]"}, {"code": "G06F3/041662", "inventive": true, "first": true, "tree": "[]"}, {"code": "G06F3/041662", "inventive": true, "first": true, "tree": "[]"}, {"code": "G06F2203/04105", "inventive": false, "first": false, "tree": "[]"}, {"code": "G06F2203/04107", "inventive": false, "first": false, "tree": "[]"}, {"code": "G06F3/0445", "inventive": true, "first": false, "tree": "[]"}, {"code": "G06F3/0446", "inventive": true, "first": false, "tree": "[]"}, {"code": "G06F3/04162", "inventive": true, "first": false, "tree": "[]"}, {"code": "G06F3/0442", "inventive": true, "first": false, "tree": "[]"}, {"code": "G06F3/04164", "inventive": false, "first": false, "tree": "[]"}, {"code": "G06F3/0448", "inventive": true, "first": false, "tree": "[]"}, {"code": "G06F3/04162", "inventive": true, "first": false, "tree": "[]"}, {"code": "G06F3/04164", "inventive": false, "first": false, "tree": "[]"}, {"code": "G06F3/0442", "inventive": true, "first": false, "tree": "[]"}, {"code": "G06F3/0445", "inventive": true, "first": false, "tree": "[]"}, {"code": "G06F3/0446", "inventive": true, "first": false, "tree": "[]"}, {"code": "G06F3/0448", "inventive": true, "first": false, "tree": "[]"}, {"code": "G06F2203/04105", "inventive": false, "first": false, "tree": "[]"}, {"code": "G06F2203/04106", "inventive": false, "first": false, "tree": "[]"}, {"code": "G06F2203/04107", "inventive": false, "first": false, "tree": "[]"}, {"code": "G06F2203/04108", "inventive": false, "first": false, "tree": "[]"}]
Family ID: 63963480