Pixelated self-capacitive water repellent

Abstract

The present application relates to pixelated self-capacitive water repulsion. A touch sensor panel is disclosed. In some examples, the touch sensor panel includes a plurality of touch node electrodes. In some examples, the touch sensor panel includes a touch controller configured to: drive and sense the plurality of touch node electrodes in a fully bootstrapped configuration to obtain a fully bootstrapped touch image; drive and sense the plurality of touch node electrodes in a second configuration different from the fully bootstrapped configuration to obtain a second touch image, the second touch image including the effect of water on the touch sensor panel; and determine a final touch image based on the fully bootstrapped touch image and the second touch image, the final touch image not including the effect of water on the touch sensor panel. In some examples, the second configuration includes a mutual capacitance configuration. In some examples, the second configuration includes a partially bootstrapped configuration.

Description

[0001] This application is a divisional application of an invention patent application with an international application date of October 27, 2015, a national application number of 201580058366.7, and an invention name of “Pixelated Self-Capacitive Water Repulsion”.

[0002] Cross-references to related patent applications

[0003] This patent application claims the benefit of U.S. Provisional Patent Application No. 62 / 069,231, filed October 27, 2014, the entire disclosure of which is incorporated herein by reference for all purposes. Technical Field

[0004] The present invention relates generally to touch sensor panels and, more particularly, to repelling water on a pixelated self-capacitive touch sensor panel. Background Art

[0005] Many types of input devices are currently available for performing operations in computing systems, such as buttons or keys, mice, trackballs, joysticks, touch sensor panels, touch screens, and the like. Specifically, touch screens are becoming increasingly popular due to their ease and flexibility in operation and their ever-decreasing prices. A touch screen may include a touch sensor panel and a display device such as a liquid crystal display (LCD), the touch sensor panel being a transparent panel having a touch-sensitive surface, the display device being partially or completely positioned behind the panel so that the touch-sensitive surface may cover at least a portion of the visible area of ​​the display device. The touch screen may allow a user to perform various functions by touching the touch sensor panel at a position often indicated by a user interface (UI) displayed by the display device using a finger, stylus, or other object. Generally speaking, the touch screen may identify a touch and the location of the touch on the touch sensor panel, and the computing system may then interpret the touch according to the display content that appears when the touch occurs, and may then perform one or more actions based on the touch. For some touch sensing systems, detecting a touch does not require a physical touch on the display. For example, in some capacitive touch sensing systems, the fringing electric field used to detect touch may extend beyond the surface of the display, and objects approaching the surface may be detected as being near the surface without actually contacting the surface.

[0006] The capacitive touch sensor panel may be formed from a matrix of substantially transparent or opaque conductive plates made of a material such as indium tin oxide (ITO). As described above, in part due to their substantial transparency, some capacitive touch sensor panels may be overlaid on a display to form a touch screen. Some touch screens may be formed by at least partially integrating touch sensing circuitry into a display pixel stack structure (i.e., the stacked material layers that form the display pixels). Summary of the invention

[0007] Some capacitive touch sensor panels may be formed by a matrix of substantially transparent or opaque conductive plates made of materials such as indium tin oxide (ITO), while some touch screens may be formed by integrating touch sensing circuitry at least partially into a display pixel stack structure (i.e., stacked material layers forming display pixels). Touch events may be sensed on the touch screen by detecting changes in the self-capacitance of the conductive plates (touch node electrodes). In some examples, water or water droplets may be present on the touch screen of the present disclosure. It is also beneficial to be able to distinguish water (e.g., water droplets) that may be present on the touch screen from finger touch activity, the former of which may be ignored and the latter of which may be processed as touch activity. In some examples, isolated water droplets on the touch screen of the present disclosure (i.e., water droplets that are not in contact with a grounded user or object) may not appear on a full bootstrap scan of the touch screen, but may appear to varying degrees on a partial bootstrap scan of the touch screen as well as a mutual capacitance scan. Therefore, a comparison of a full bootstrap scan of the touch screen and a partial bootstrap scan and / or mutual capacitance scan of the touch screen may be used to identify the presence of water on the touch screen, and the water may be ignored or discarded from a final touch image that can be used to analyze touch activity. BRIEF DESCRIPTION OF THE DRAWINGS

[0008] Figure 1A-Figure 1C An exemplary mobile phone, an exemplary media player, and an exemplary portable computing device are shown that can each include an exemplary touch screen according to examples of the present disclosure.

[0009] Figure 2 is a block diagram of an exemplary computing system illustrating one implementation of an exemplary touch screen according to examples of the present disclosure.

[0010] Figure 3 An exemplary touch sensor circuit corresponding to self-capacitance touch node electrodes and sensing circuits according to examples of the present disclosure is shown.

[0011] Figure 4 An exemplary configuration is shown in which a common electrode may form part of a touch sensing circuit of a touch sensing system according to examples of the present disclosure.

[0012] Figure 5A An exemplary fully bootstrapped touch screen is shown in which each touch node electrode can be driven and sensed simultaneously according to examples of the present disclosure.

[0013] Figure 5B An exemplary partial bootstrap touch screen is shown in which only a portion of the touch node electrodes can be driven and sensed simultaneously according to examples of the present disclosure.

[0014] Fig. 6AAn exemplary fully bootstrapped touch screen is shown on which an isolated water droplet may reside according to examples of the present disclosure.

[0015] Figure 6B An exemplary partially bootstrapped touch screen is shown on which an isolated water droplet may reside according to examples of the present disclosure.

[0016] Figure 6C An exemplary touch screen operating in a mutual capacitance configuration on which an isolated water droplet may reside is shown according to examples of the present disclosure.

[0017] Fig. 7A An exemplary configuration of a partially bootstrapped touch screen with touch nodes coupled to appropriate circuitry according to examples of the present disclosure is shown.

[0018] Figure 7B An exemplary configuration of a partially bootstrapped touch screen that can utilize a switch array to couple appropriate circuitry to touch nodes according to examples of the present disclosure is shown.

[0019] Fig. 8A An exemplary fully bootstrapped scan on a touch screen according to examples of the present disclosure is shown.

[0020] Figure 8B An exemplary partial bootstrap scan on a touch screen according to examples of the present disclosure is shown.

[0021] Figure 8C An exemplary full bootstrap scan with reduced resolution on a touch screen according to examples of the present disclosure is shown.

[0022] Fig. 9A An exemplary fully bootstrapped scan on a touch screen according to examples of the present disclosure is shown.

[0023] Fig. 9B An exemplary mutual capacitance scanning on a touch screen according to examples of the present disclosure is shown.

[0024] Fig. 9C An exemplary full bootstrap scan with reduced resolution on a touch screen according to examples of the present disclosure is shown.

[0025] Fig. 10A Exemplary basic touch screen display frame and touch frame configurations according to examples of the present disclosure are shown.

[0026] Fig. 10B An example according to the present disclosure is shown. Fig. 10A Exemplary details of some of the bootstrap scanning steps in .

[0027] Fig.11A Exemplary water detection and water repellency display frame and touch frame configurations according to examples of the present disclosure are shown.

[0028] Fig. 11B Another exemplary water detection and water repellency display frame and touch frame configuration according to examples of the present disclosure is shown.

[0029] Fig. 11C An example according to the present disclosure is shown. Fig. 11B Exemplary details of the full bootstrap scanning step in .

[0030] Fig.11D An example according to the present disclosure is shown. Fig.11A An exemplary process corresponding to the water detection and water rejection steps in FIG.

[0031] Fig.11E An example according to the present disclosure is shown. Fig. 11B An exemplary process corresponding to the water detection and water rejection steps in FIG.

[0032] Fig. 12A Exemplary water detection and water repellency display frame and touch frame configurations according to examples of the present disclosure are shown.

[0033] Fig. 12B An example according to the present disclosure is shown. Fig. 12A Example details of the mutual capacitance scanning steps in FIG.

[0034] Fig. 12C An example according to the present disclosure is shown. Fig. 12A An exemplary process corresponding to the water detection and water rejection steps in FIG.

[0035] Fig.13A Exemplary dynamic water detection and water repelling display frame and touch frame configurations in ready mode according to examples of the present disclosure are shown.

[0036] Fig. 13B An exemplary dynamic water detection and water repelling display frame and touch frame configuration in an active mode according to examples of the present disclosure is shown.

[0037] Fig. 13C An example according to the present disclosure is shown. Fig. 13B An exemplary process corresponding to the water detection and water rejection steps in FIG.

[0038] Fig.13D An example according to the present disclosure is shown. Fig. 13B Another exemplary process corresponding to the water detection and water rejection steps in.

[0039] Fig.14A Exemplary default display frame and touch frame configurations according to examples of the present disclosure are shown.

[0040] Fig. 14BExemplary display frame and touch frame configurations for touch screen operation in a partial bootstrap mode of operation according to examples of the present disclosure are shown.

[0041] Fig. 14C Exemplary conditions that enable the touch screen of the present invention to switch between full bootstrap operation and partial bootstrap operation according to an example of the present disclosure are shown.

[0042] Fig.14D An example according to the present disclosure is shown. Fig.14A An exemplary process corresponding to the water detection and water rejection steps in FIG.

[0043] Fig.14E An example according to the present disclosure is shown. Fig. 14B An exemplary process corresponding to the water detection and water rejection steps in FIG.

[0044] Fig.15A An exemplary driving and sensing scheme is shown in which each touch node electrode on a touch screen may be driven and sensed at a certain point in time according to examples of the present disclosure.

[0045] Fig. 15B An exemplary mutual capacitance drive and sense scheme that may be used with the touch screen of the present disclosure is shown.

[0046] Fig. 15C Various capacitances associated with the mutual capacitance drive and sense scheme of the present disclosure are shown. DETAILED DESCRIPTION

[0047] In the following description of the examples, reference will be made to the accompanying drawings which form a part of the following description and in which are shown by way of example specific examples that can be implemented. It should be understood that other examples can be used and structural changes can be made without departing from the scope of the disclosed examples.

[0048] Some capacitive touch sensor panels may be formed by a matrix of substantially transparent or opaque conductive plates made of materials such as indium tin oxide (ITO), while some touch screens may be formed by integrating touch sensing circuitry at least partially into a display pixel stack structure (i.e., stacked material layers forming display pixels). Touch events may be sensed on the touch screen by detecting changes in the self-capacitance of the conductive plates (touch node electrodes). In some examples, water or water droplets may be present on the touch screen of the present disclosure. It is also beneficial to be able to distinguish water (e.g., water droplets) that may be present on the touch screen from finger touch activity, the former of which may be ignored and the latter of which may be processed as touch activity. In some examples, isolated water droplets on the touch screen of the present disclosure (i.e., water droplets that are not in contact with a grounded user or object) may not appear on a full bootstrap scan of the touch screen, but may appear to varying degrees on a partial bootstrap scan of the touch screen as well as a mutual capacitance scan. Therefore, a comparison of a full bootstrap scan of the touch screen and a partial bootstrap scan and / or mutual capacitance scan of the touch screen may be used to identify the presence of water on the touch screen, and the water may be ignored or discarded from a final touch image that can be used to analyze touch activity. Although examples of the present disclosure are described with reference to water, it should be understood that examples of the present disclosure can be used to detect liquids other than water on a touch screen, and more generally, to detect the presence of an ungrounded object on a touch screen.

[0049] Figure 1A-Figure 1C An exemplary system is shown in which a touch screen according to examples of the present disclosure may be implemented. Figure 1A An exemplary mobile phone 136 including a touch screen 124 is shown. Figure 1B An example digital media player 140 including a touch screen 126 is shown. Figure 1C An exemplary portable computing device 144 including a touch screen 128 is shown. Touch screens 124, 126, and 128 may be based on self-capacitance. It should be appreciated that the above-described touch screens may also be implemented in other devices, including wearable devices. A touch system based on self-capacitance may include a matrix of individual conductive material plates, which may be referred to as touch node electrodes (hereinafter referred to as touch node electrodes). Figure 2220 in the embodiment of the present invention). For example, the touch screen may include a plurality of individual touch node electrodes, each of which identifies or represents a unique location on the touch screen for sensing touch or proximity (hover) (i.e., a touch event or proximity event), and each of which is electrically isolated from other touch node electrodes in the touch screen / panel. Such a touch screen may be referred to as a pixelated self-capacitance touch screen, but it should be understood that in some examples, the touch node electrodes on the touch screen may be used to perform scans other than self-capacitance scans (e.g., mutual capacitance scans) on the touch screen. During operation, the touch node electrodes may be stimulated with an AC waveform, and the self-capacitance to the ground of the touch node electrodes may be measured. When an object approaches the touch node electrodes, the self-capacitance to the ground of the touch node electrodes may change. Such changes in the self-capacitance of the touch node electrodes may be detected and measured by the touch sensing system to determine the locations of multiple objects when they touch or approach the touch screen. In some examples, the electrodes of a self-capacitance-based touch system may be formed by rows and columns of conductive material, and similar to the above, changes in the self-capacitance to the ground of the rows and columns may be detected. In some examples, the touch screen can be multi-touch, single-touch, projection scanning, full-imaging multi-touch, capacitive touch, etc.

[0050] Figure 2 2 is a block diagram of an exemplary computing system 200 illustrating one specific implementation of an exemplary touch screen 220 according to examples of the present disclosure. The computing system 200 may be included, for example, in a mobile phone 136, a digital media player 140, a portable computing device 144, or any mobile computing device or non-mobile computing device including a touch screen, including a wearable device. The computing system 200 may include a touch sensing system including one or more touch processors 202, a peripheral device 204, a touch controller 206, and a touch sensing circuit (described in more detail below). The peripheral device 204 may include, but is not limited to, a random access memory (RAM) or other type of memory or storage device, a watchdog timer, and the like. The touch controller 206 may include, but is not limited to, one or more sensing channels 208 and a channel scanning logic component 210. The channel scanning logic component 210 may access the RAM 212, autonomously read data from the sensing channel 208, and provide control for the sensing channel. Additionally, channel scan logic 210 can control sense channels 208 to generate excitation signals at various frequencies and phases that can be selectively applied to touch node electrodes of touch screen 220, as described in greater 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.

[0051] The touch screen 220 may include touch sensing circuitry that may include a capacitive sensing medium (e.g., a pixelated self-capacitive touch screen) having a plurality of electrically isolated touch node electrodes 222. The touch node electrodes 222 may be coupled to the sensing channels 208 in the touch controller 206, may be driven by an excitation signal from the sensing channels through the drive / sense interface 225, and may also be sensed by the sensing channels through the drive / sense interface, as described above. When the touch screen 220 is viewed as capturing an "image" of touch (e.g., a "touch image"), it may be particularly useful to label the conductive plates used to detect touch (i.e., the touch node electrodes 222) as "touch node" electrodes. In other words, after the touch controller 206 determines the amount of touch detected at each touch node electrode 222 in the touch screen 220, the pattern of touch node electrodes in the touch screen where touches occur may be viewed as a touch image (e.g., a pattern of fingers touching the touch screen).

[0052] The computing system 200 may also include a host processor 228 for receiving outputs from the touch processor 202 and performing actions based on the outputs. For example, the host processor 228 may be connected to a program storage device 232 and a display, controller such as an LCD driver 234. The LCD driver 234 may provide a voltage to each pixel transistor on a select (gate) line and may provide data signals to these same transistors along a data line to control the pixels to display an image, as described in more detail below. The host processor 228 may use the LCD driver 234 to generate a display image such as a user interface (UI) display image on the touch screen 220, and may use the touch processor 202 and the touch controller 206 to detect a touch on or near the touch screen 220. Touch input may be used by a computer program stored in program storage device 232 to perform actions, which may include, but are not limited to, moving an object such as a cursor or pointer, scrolling or panning, adjusting a control setting, opening a file or document, viewing a menu, making a selection, executing an instruction, operating a peripheral device connected to the host device, answering a phone call, placing a phone call, terminating a phone call, changing 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 computer network, allowing authorized individuals to access restricted areas of a computer or computer network, loading a user profile associated with a user's preferred arrangement of a computer desktop, allowing access to web page content, launching a particular program, encrypting or decrypting a message, etc. Host processor 228 may also perform additional functions that may not be related to touch processing.

[0053] It is noted that one or more of the functions described above, including the configuration and operation of electrodes and sensing channels, may be implemented by a memory device (e.g., Figure 2The firmware may be stored in one of the peripheral devices 204 in the touch processor 202 or in a firmware stored in the program storage device 232 and executed by the host processor 228. The firmware may also be stored and / or transmitted in any non-transitory computer-readable storage medium for use by or in conjunction with an instruction execution system, apparatus, or device, such as a computer-based system, a system including a processor, or other system that can obtain instructions from and execute instructions to an instruction execution system, apparatus, or device. In the context of this document, a "non-transitory computer-readable storage medium" may be any medium (excluding signals) that can contain or store a program for use by or in conjunction with an instruction execution system, apparatus, or device. Computer-readable storage media may include, but are not limited to, electronic, magnetic, optical, electromagnetic, infrared or semiconductor systems, apparatuses or devices, portable computer disks (magnetic), random access memory (RAM) (magnetic), read-only memory (ROM) (magnetic), erasable programmable read-only memory (EPROM) (magnetic), portable optical disks such as CD, CD-R, CD-RW, DVD, DVD-R or DVD-RW, or flash memory such as compact flash cards, secure digital cards, USB storage devices, memory sticks, etc.

[0054] The firmware may also be transmitted in any transmission medium for use or in conjunction with an instruction execution system, device or apparatus, such as a computer-based system, a system containing a processor, or other system that obtains instructions from and executes instructions on an instruction execution system, device or apparatus. In the context of this document, a "transmission medium" may be any medium that can transmit, propagate or transport a program for use or in conjunction with an instruction execution system, device or apparatus. Transmission media may include, but are not limited to, electronic, magnetic, optical, electromagnetic or infrared wired or wireless transmission media.

[0055] Figure 3An exemplary touch sensor circuit 300 corresponding to a self-capacitive touch node electrode 302 and a sensing circuit 314 according to an example of the present disclosure is shown. The touch node electrode 302 may correspond to the touch node electrode 222. The touch node electrode 302 may have an inherent self-capacitance to a ground portion associated therewith, and an additional self-capacitance to the ground portion that is formed only when an object (such as a finger 305) approaches or contacts the electrode. The total self-capacitance of the touch node electrode 302 to the ground portion may be shown as capacitance 304. The touch node electrode 302 may be coupled to a sensing circuit 314 (which may correspond to a sensing channel 208). Although other configurations may be used, the sensing circuit 314 may include an operational amplifier 308, a feedback resistor 312, a feedback capacitor 310, and an input voltage source 306. For example, the feedback resistor 312 may be replaced by a switched capacitor resistor to minimize parasitic capacitance effects that may be caused by a variable feedback resistor. The touch node electrode 302 may be coupled to the inverting input terminal (-) of the operational amplifier 308. An AC voltage source 306 (Vac) may be coupled to the non-inverting input (+) of an operational amplifier 308. The touch sensor circuit 300 may be configured to sense changes in the total self-capacitance 304 of the touch node electrode 302 caused by a finger or object touching or approaching the touch sensor panel. The output 320 may be used by a processor (e.g., touch controller 206) to determine the presence of a proximity event or touch event, or the output may be input into a discrete logic network to determine the presence of a touch event or proximity event. It should be understood that a "touch event" as used in the present disclosure may include a finger or object touching the touch sensor panel (i.e., physically contacting the touch sensor panel), as well as a finger or object approaching but not contacting the touch sensor panel (e.g., hovering over the touch sensor panel).

[0056] Re-reference Figure 2 In some examples, touch screen 220 may be an integrated touch screen in which touch sensing circuit elements of a touch sensing system may be integrated into a display pixel stack structure of a display. Circuit elements in touch screen 220 may include, for example, elements that may be present in an LCD or other display, such as one or more pixel transistors (e.g., thin film transistors (TFTs)), gate lines, data lines, pixel electrodes, and common electrodes. In a given display pixel, the voltage between the pixel electrode and the common electrode may control the brightness of the display pixel. The voltage on the pixel electrode may be provided by the data line through a pixel transistor, which may be controlled by a gate line. It should be noted that circuit elements are not limited to entire circuit components, such as an entire capacitor, an entire transistor, etc., but may include portions of a circuit, such as one of the two plates of a parallel plate capacitor. Figure 4An exemplary configuration is shown in which common electrodes 402 may form part of touch sensing circuitry of a touch sensing system - in some examples of the present disclosure, common electrodes may form touch node electrodes for detecting touch images on touch screen 400, as described above. Each common electrode 402 (i.e., touch node electrode) may include a plurality of display pixels 401 (shown as small squares with dashed borders), and each display pixel 401 may include a portion of a common electrode 402, which may be a circuit element of a display system circuitry in a display pixel stackup structure (i.e., stacked material layers that form a display pixel) of a display pixel of some type of LCD or other display - in other words, the common electrodes may operate as part of a display system to display a display image on touch screen 400.

[0057] exist Figure 4 In the example shown, each common electrode 402 can be used as a multifunctional circuit element, which can be operated as a display circuit of the display system of the touch screen 400, and can also be operated as a touch sensing circuit of the touch sensing system. In this example, as described above, each common electrode 402 can be operated as a common electrode of the display circuit of the touch screen 400, and can also be operated as a touch sensing circuit of the touch screen. For example, during the touch sensing phase, the common electrode 402 can be operated as a capacitive portion of the touch node electrode of the touch sensing circuit. Other circuit elements of the touch screen 400 can form a part of the touch sensing circuit by means of, for example, switch electrical connection. More specifically, in some examples, during the touch sensing phase, the gate line can be connected to a power supply such as a charge pump, which can apply a voltage to keep the TFT in the display pixel included in the touch node electrode in the "off" state. An excitation signal can be applied to the common electrode 402. As previously described, the change in the total self-capacitance of the common electrode 402 can be sensed by an operational amplifier. The change in the total self-capacitance of the common electrode 402 can depend on the proximity of the touch object (such as the finger 305) to the common electrode. In this manner, changes in the measured total capacitance of the common electrode 402 can provide an indication of a touch on or near the touch screen.

[0058] Typically, each of the touch sensing circuit elements may be a multifunctional circuit element that may form part of a touch sensing circuit and may perform one or more other functions such as forming part of a display circuit, or each of the touch sensing circuit elements may be a single-function circuit element that may only operate as a touch sensing circuit. Similarly, each of the display circuit elements may be a multifunctional circuit element that may operate as a display circuit and may perform one or more other functions such as operating as a touch sensing circuit, or each of the display circuit elements may be a single-function circuit element that may only operate as a display circuit. Thus, in some examples, some of the circuit elements in the display pixel stack structure may be multifunctional circuit elements, while other circuit elements may be single-function circuit elements. In other examples, all of the circuit elements in the display pixel stack structure may be single-function circuit elements.

[0059] In addition, although the examples herein may describe the display circuit as operating during the display phase and the touch sensing circuit as operating during the touch sensing phase, it should be understood that the display phase and the touch sensing phase may operate simultaneously, such as partially or completely overlapping, or the display phase and the touch sensing phase may operate at different times. Moreover, although the examples herein describe certain circuit elements as being multifunctional and other circuit elements as being single-function, it should be understood that in other examples the circuit elements are not limited to a particular function. In other words, a circuit element described as a single-function circuit in one example herein may be configured as a multifunctional circuit in other examples, and vice versa.

[0060] Figure 4 The common electrodes 402 (i.e., touch node electrodes) and display pixels 401 are shown as rectangular or square areas on the touch screen 400. However, it should be understood that the common electrodes 402 and display pixels 401 are not limited to the shapes, orientations, and positions shown, but may include any suitable configuration according to examples of the present disclosure.

[0061] Although the present disclosure focuses on touch screens, it should be understood that some or all examples of the present invention may be similarly implemented in a touch sensor panel (i.e., a panel having touch sensing circuitry without display circuitry). However, for simplicity, examples of the present invention have been and will be described in the context of a touch screen.

[0062] Water Repellent

[0063] In a self-capacitive touch screen, the capacitance seen by a self-capacitive touch node electrode can affect the total self-capacitance measured at the touch node electrode, and therefore affect the touch measurement at the touch node electrode. Therefore, in some examples, in order to reduce or eliminate unnecessary capacitance that may contribute to the total self-capacitance measured at the touch node electrode, it can be beneficial to make the touch screen "bootstrapped". Making the touch screen "bootstrapped" may require driving one or more components or portions of the touch screen (as described above) with a voltage of the same frequency and phase as used to drive and sense the touch node electrodes, so that the capacitance that may exist between the touch node electrodes and one or more portions of the touch screen can be effectively eliminated. For example, making the touch screen bootstrapped may require driving one or more gate lines of the touch screen with a voltage of the same frequency and phase as used to drive and sense the touch node electrodes. It is also beneficial to be able to distinguish between water (e.g., water droplets) that may be present on the touch screen and finger touch activity, the former of which can be ignored and the latter of which can be processed as touch activity. It should be noted that although the water detection and water rejection examples of the present invention are described in the context of a bootstrapped touch screen, the water detection and water rejection schemes can be similarly applied to touch sensor panels (not just touch screens) in which no bootstrapped occurs, but the touch node electrodes are driven, sensed and / or grounded as described below.

[0064] Figure 5A An exemplary fully bootstrapped touch screen 500 is shown in which each touch node electrode can be driven and sensed simultaneously. Touch screen 500 may include touch node electrodes 502, 504, 506, and 508. Touch node electrodes 502, 504, 506, and 508 may be a portion of the touch node electrodes that may be included in touch screen 500. For ease of description, other touch node electrodes are omitted, but it should be understood that the scope of the present disclosure includes touch screens having more than four touch node electrodes. In some examples, all touch node electrodes on the touch screen can be driven and sensed simultaneously in a fully bootstrapped configuration. In some examples, the touch screen can be sensed in a fully bootstrapped configuration and in portions (e.g., 25% of the touch screen is sensed at a time, similar to the reference 3D image). Fig. 10B In some examples, the touch node electrodes in those portions of the touch screen that are not currently being sensed in the full bootstrap configuration may be biased at a bias voltage (AC or DC) or may be driven with the same excitation signal as the excitation signal used to drive and sense the touch node electrodes in the portion of the touch screen that is currently being sensed in the full bootstrap configuration.

[0065] Each of the touch node electrodes 502, 504, 506, and 508 may be driven and sensed (denoted by “DS”) simultaneously (or sequentially sensed when driven) by the same excitation signal from an excitation source 514, which may be coupled to a device (e.g., Figure 1A-Figure 1C The excitation source 514 may correspond to a system ground 516 of any device shown in FIG. Figure 3 504, 506, and 508 are shown as being coupled to the same excitation source 514, it should be understood that substantially the same results may be obtained if the touch node electrodes are coupled to any combination of different excitation sources providing the same excitation signal. Since each of the touch node electrodes 502, 504, 506, and 508 may be driven and sensed simultaneously (or sensed sequentially when driven) using the same excitation signal, capacitance that may exist between the touch node electrodes may be effectively cancelled, and the total self-capacitance of the sensed touch node electrodes may be limited to capacitance that may exist between the touch node electrodes and the finger (or object) 518, and other potential capacitances (e.g., parasitic capacitances) that may exist between the touch node electrodes and other system components (e.g., system ground). These capacitances may be represented by C1 503, C2 505, C3 507, and C4 509.

[0066] like Figure 5A As shown, C g 520 may represent the total capacitance between finger 518 and system ground, and may be a combination of various capacitances, as described below. Specifically, finger 518 may have a capacitance C between itself and ground. 人体 , where C 人体 It can represent, for example, the capacitance from a human body to the earth. Finger 518 can also have a capacitance C between itself and a device that can include touch screen 500. F-SG , where C F-SG The device including the touch screen 500 may have a capacitance C between itself and the ground. SG-EG , where C SG-EG It can represent the capacitance from the system (equipment) ground to the earth. In some examples, C 人体 Comparable C F-SG and C SG-EG Therefore, it can be considered that finger 518 effectively passes through C 人体 Therefore, it can be considered that C SG-EG Between the system (equipment) ground and finger 518 (which can be shorted to the ground); and from the foregoing, it can be seen that C F-SG It can be another capacitance between the system (device) ground and finger 518. CF-SG and C SG-EG Therefore, a parallel capacitance may exist between the finger 518 and the system ground 516. Thus, the total capacitance C between the finger 518 and the system ground g 520 can be represented as:

[0067] C g =C F-SG +C SG-EG (1)

[0068] The current from the touch node electrodes 502, 504, 506 and 508 can flow through the finger 518 and C g 520 and flows to the system ground 516. However, due to the g The impedance associated with 520 can at least partially isolate finger 518 from system ground 516, so as more current flows from touch node electrodes 502, 504, 506, and 508 through finger 518 and to system ground 516, the voltage at finger 518 can move increasingly further away from system ground 516. Because each of touch node electrodes 502, 504, 506, and 508 can be driven and sensed simultaneously, current from all four touch node electrodes can flow through finger 518 and to system ground 516. As a result, the voltage at finger 518 can be relatively high relative to system ground, and the voltage drop across each of C1 503, C2 505, C3 507, and C4 509 can be relatively smaller, which can result in reduced charge coupling and an attenuation of the capacitance sensed at each of the touch node electrodes associated with capacitances C1, C2, C3, and C4. This attenuation may be reflected in an attenuation factor by which each of the C1 503, C2 505, C3 507 and C4 509 capacitors may be multiplied, which may be expressed as:

[0069] α=C g / C 总 (2)

[0070] where α represents the attenuation factor, and:

[0071] C 总 =C g +C1+C2+C3+C4 (3)

[0072] Therefore, the effective self-capacitance sensed at any touch node electrode can be expressed as:

[0073] C 有效，X =α*C X (4)

[0074] Among them C XThis attenuation of the sensed self-capacitance of the touch node electrodes can make it difficult to sense a touch on the touch screen 500. In some examples, the touch screen 500 includes more touch node electrodes that are all driven and sensed simultaneously, and many parts of the user's hand (or other object) are close to / contacting the touch screen (e.g., the user's palm, thumb, and multiple fingers are in contact with the touch screen), and the attenuation factor α can be as low as 4%. It should be understood that in some examples, the finger 518 can be well grounded, in which case C g α may be very large (or infinite), and α may be approximately 1 (i.e., no attenuation). In the case where finger 518 is not grounded, it may be difficult to detect a touch because the touch signal is attenuated to a very large extent. In some examples, the amount of touch signal attenuation that may be present may be reduced by partially, rather than completely, bootstrapping the touch screen.

[0075] Figure 5B An exemplary partially bootstrapped touch screen 501 is shown in which only a portion of the touch node electrodes can be driven and sensed at a given moment. Touch screen 501 can be substantially the same as touch screen 500, except that in touch screen 500, touch node electrodes 502, 504, 506, and 508 are all driven and sensed simultaneously, whereas in touch screen 501, only touch node electrode 502 (touch node electrode DS) can be driven and sensed. Touch node electrodes 504 and 506 (touch node electrode D) can be driven but not sensed, and touch node electrode 508 (touch node electrode G) can be grounded to system ground 516. Although not shown for clarity, touch node electrodes 504 and 506 can be coupled to an excitation source so as to be driven by the same excitation signal that is driving touch node electrode 502. Additionally, it should be understood that when the number of touch node electrodes is greater than the number of touch node electrodes, the system ground 516 can be grounded. Figure 5B In more touch screens shown, according to examples of the present disclosure, DS, D, and G touch node electrode patterns can be repeated on a portion of the touch screen or on the entire touch screen. In addition, in some examples, a partial bootstrap scan of the touch screen can include at least one touch node electrode being driven and sensed, and at least one touch node electrode being grounded, and the remaining touch node electrodes can be driven and sensed, driven only, grounded, floating, or in any other electrical state.

[0076] Partially bootstrapped touch screen 501 can exhibit many of the benefits of fully bootstrapped touch screen 500. Specifically, because touch node electrodes 502, 504, and 506 can be driven using the same excitation signal, the capacitance between touch node electrode 502 (the target touch node electrode, i.e., the touch node electrode whose total self-capacitance is sensed) and touch node electrodes 504 and 506 can continue to be effectively canceled. The capacitance between touch node electrode 502 and touch node electrode 508 may not be canceled because touch node electrode 508 can be coupled to system ground 516; however, because touch node electrodes 502 and 508 can be arranged diagonally relative to each other (although it should be understood that they do not have to be arranged in this way), the capacitance that may exist between the two can be relatively small. Therefore, the total self-capacitance sensed at touch node electrode 502 can be substantially free of capacitance that may exist between touch node electrode 502 and other touch node electrodes, which can be a benefit of a fully bootstrapped touch screen.

[0077] Compared to the fully bootstrapped touch screen 500, the partially bootstrapped touch screen 501 may also exhibit less touch signal attenuation. In the touch screen 500, the only current path from the touch node electrode to the ground may flow through the finger 518 and C g 520, and in the touch screen 501, the current from the touch node electrode to the ground portion can flow through C4 509 and flow to the system ground portion 516, and can also flow through the finger 518 and C g 520. Therefore, the voltage at the finger 518 may drop closer to the system ground 516, which may cause a larger voltage drop across C1 503 than in the touch screen 500; thus, more charge coupling and less attenuation of C1 503 may be sensed at the touch node electrode 502. The partial bootstrap touch screen attenuation factor may be expressed as:

[0078] α=(C g +C4) / C 总 (5)

[0079] Similar to the previous text, the effective self-capacitance sensed at the touch node electrode 502 can be expressed as:

[0080] C 有效，1 =α*C1 (6)

[0081] In the example where touch screen 501 includes more touch node electrodes that are driven, sensed, and grounded in the illustrated partial bootstrap mode while many parts of the user's hand are in proximity / contact with the touch screen (e.g., the user's palm, thumb, and multiple fingers are in contact with the touch screen), in this case, the attenuation coefficient can be increased from ~4% in a fully bootstrap touch screen to ~25% in a partially bootstrap touch screen. This increase can be caused by the C4 addition term that can be included in the numerator of equation (5), and can relax the signal-to-noise ratio requirements of the touch screen sensing circuit by more than six times compared to touch screen 500, which can reduce the difficulty of sensing touch on the touch screen.

[0082] As described above, in some examples, water or water droplets may be present on the touch screen of the present disclosure. Being able to distinguish between the presence of water and the presence of a finger is beneficial for ensuring proper touch screen operation.

[0083] Fig. 6A FIG. 6 shows an exemplary fully bootstrapped touch screen 600 on which an isolated water droplet 619 may reside, according to an example of the present disclosure. The touch screen 600 may be substantially similar to Figure 5A 5, except that finger 518 may be replaced by isolated water drop 619. Isolated water drop 619 may be a water drop that may reside on the surface of touch screen 600 and may be "isolated" in that it may not touch the user, the user's finger, or any other object that may be at least partially grounded. As in touch screen 500, touch screen 600 may be fully bootstrapped.

[0084] Since the isolated water drop 619 can be isolated from the ground, there is no path from the water drop to the ground, so no current can flow from the touch node electrodes 602, 604, 606 and 608 through the isolated water drop to the ground. As a result, the isolated water drop 619 can cause the self-capacitance of any of the touch node electrodes 602, 604, 606 and 608 to be substantially unchanged, so the isolated water drop does not bring its own self-capacitance touch image. In other words, for a fully bootstrap touch screen, the water drop can be automatically ignored / discarded from the touch scan.

[0085] However, for the reasons described above, sometimes the touch screen of the present disclosure may operate in a partially bootstrapped configuration. Figure 6B FIG. 6 shows an exemplary partially bootstrapped touch screen 601 on which an isolated water droplet 619 may reside, according to an example of the present disclosure. The touch screen 601 may be substantially similar to Figure 5B The touch screen 501 in FIG. 5 is different in that the finger 518 can be replaced by an isolated water droplet 619, such as Fig. 6A Like. Fig. 6AUnlike the example shown, since the touch screen 601 may be partially bootstrapped, a path from the water drop 619 to the ground may exist. Specifically, the water drop 619 may be coupled to the ground 616 through C4 609 and the touch node electrode 608. As a result, current may flow from the touch node electrodes 602, 604, and 606 through the water drop 619 to the ground 616. Therefore, the water drop 619 may appear in the self-capacitive touch image acquired on the partially bootstrapped touch screen 601.

[0086] Based on the above Figure 5B For similar reasons as described above, the attenuation factor associated with water drop 619 can be expressed as:

[0087] α=C4 / C 总 (7)

[0088] Similar to the previous text, the effective self-capacitance sensed at the touch node electrode 602 can be expressed as:

[0089] C 有效，1 =α*C1 (8)

[0090] Therefore, in the partial bootstrap configuration, an attenuated self-capacitive touch image of the water drop 619 may be detected on the touch screen 601 .

[0091] In some examples, the touch screen of the present disclosure may additionally or alternatively operate in a mutual capacitance configuration. In some examples, the touch screen may operate in a mutual capacitance configuration to correct for the above-mentioned attenuation associated with an ungrounded (or poorly grounded) user, and in some examples, the touch screen may operate in a mutual capacitance configuration as part of separating and repelling water from actual touch activity, as will be described herein. Ungrounded user attenuation correction will be discussed later in this disclosure. Figure 6C An exemplary touch screen 650 is shown on which an isolated water droplet 619 may reside, operating in a mutual capacitance configuration according to an example of the present disclosure. The mutual capacitance drive and sense scheme shown may be used before, after, or in the above-described full / partial bootstrap scheme, as will be described in more detail later herein, Figure 6C An exemplary mutual capacitance drive and sensing scheme of FIG. 1 is illustrated as applied to four touch node electrodes, but it should be understood that the scheme can be similarly extended to additional touch node electrodes that may be present on the touch screen of the present disclosure. For example, a group of four touch node electrodes on the touch screen can be driven, sensed, and grounded as described below. In some examples, the group of four touch node electrodes can be driven, sensed, and grounded sequentially, i.e., one at a time. In some examples, the group of four touch node electrodes can be driven, sensed, and grounded at least partially simultaneously, i.e., more than one at a time.

[0092] The mutual capacitance driving and sensing scheme will now be described. During the first mutual capacitance scanning period, the touch node electrodes of the touch screen may be driven and sensed, such as Figure 6C As shown. Specifically, the upper left touch node electrode 602 (D touch node electrode) can be driven via an excitation source 617. The excitation source 617 can be any suitable voltage source for providing a voltage to the touch node electrode 602. The lower right touch node electrode 608 (S touch node electrode) can be sensed via a readout amplifier 620 (for example, the D touch node electrode 602 and the S touch node electrode 608 can be arranged diagonally). The upper right and lower left touch electrodes 604 and 606 (G touch node electrodes) can be grounded (or biased at another reference voltage). The above configuration of the touch node electrodes can allow the mutual capacitance between the D touch node electrode 602 and the S touch node electrode 608 to be measured separately. In some examples, mutual capacitance measurements can be obtained by using one or more excitation buffers to excite one or more D touch node electrodes on the touch screen, using one or more AC grounding buffers to ground one or more G touch node electrodes, and / or using one or more readout amplifiers (for example, sensing circuits) to sense one or more S touch node electrodes. The mechanism for causing the touch node electrodes to be driven, sensed, and / or grounded can be similar to the schemes described previously (e.g., Figure 5A-Figure 5B and Figure 6A-6B For the sake of brevity, the details of the above embodiments will not be repeated herein.

[0093] In some examples, a second mutual capacitance scan can be performed during a second mutual capacitance scan time period. During the second mutual capacitance scan time period, the touch node electrodes can be driven and sensed so that the upper right touch node electrode can be driven, the lower left touch node electrode can be sensed, and the upper left and lower right touch node electrodes can be grounded. After two mutual capacitance scan time periods, mutual capacitance measurements between each pair of diagonal touch node electrodes on the touch screen can be obtained. It should be understood that other drive and sense configurations can be used to obtain mutual capacitance measurements of examples of the present disclosure, and the configuration provided is only an example. For example, in Figure 6C In the embodiment of the present invention, instead of driving the upper left touch node electrode and sensing the lower right touch node electrode, the lower right touch node electrode can be driven and the upper left touch node electrode can be sensed to obtain substantially the same result. It should be understood that "mutual capacitance" as used in this disclosure can refer to the nominal capacitance shown between multiple components on a touch screen (e.g., between D and S touch node electrodes) or, where appropriate, the nominal capacitance change shown between multiple components of the touch screen.

[0094] Figure 6CVarious capacitances associated with the mutual capacitance driving and sensing scheme of the present disclosure are also shown. A water droplet 619 may have a capacitance C1 603 between itself and a touch node electrode 602, a capacitance C2 605 between itself and a touch node electrode 604, a capacitance C3 607 between itself and a touch node electrode 606, and a capacitance C4 609 between itself and a touch node electrode 608. When one touch node electrode is driven and another touch node electrode is sensed, a mutual capacitance through the water droplet 619 may be sensed. For example, a mutual capacitance may be sensed from the touch node electrode 602 through C1 603 to the water droplet 619 and then through the capacitance C4 608 to the touch node electrode 608. The mutual capacitance through the water droplet 619 between the touch node electrodes 602 and 608 may be represented as:

[0095] C M-水 =(C1*C4) / (C1+C2+C3+C4) (9)

[0096] Thus, water drop 619 may show up in the mutual capacitance measurement of the touch screen of the present disclosure. Although not shown, a finger or other object (whether partially or fully grounded) may similarly appear in the mutual capacitance measurement of the touch screen of the present disclosure. The inter-finger (or object) mutual capacitance between touch node electrodes 602 and 608 may be represented as:

[0097] C M-手指 =(C1*C4) / (C g +C1+C2+C3+C4) (10)

[0098] Among them C g can represent the total capacitance between the finger and the system ground, as previously combined with Figure 5A-Figure 5B As discussed.

[0099] Any suitable circuitry can be used to drive, sense, and / or ground the touch nodes of the touch screen of the present disclosure. Fig. 7A An exemplary configuration of a partially bootstrapped touch screen 700 with touch nodes coupled to appropriate circuitry is shown - i.e., a fully bootstrapped and / or mutual capacitance configuration that can operate with similar appropriate circuitry. Touch screen 700 can be substantially the same as touch screens 501 and 601. Touch nodes 702 that can be driven and sensed can be coupled to sensing circuitry 714. Sensing circuitry 714 can correspond to, for example Figure 32. The sensing circuit 314 in FIG. The touch nodes 704 and 706 that can be driven but not sensed can be coupled to the excitation buffer 716. In some examples, the sensing circuit 714 and the excitation buffer 716 can share the excitation source 720, because the touch nodes 702, 704, and 706 can be driven by the same excitation signal; however, it should be understood that the sensing circuit and the excitation buffer do not necessarily have to share the same excitation source. The touch node 708 that can be grounded can be coupled to the AC ground buffer 718. The voltage source 722 can provide a DC bias voltage provided by the AC ground buffer 718 to the AC ground. In some examples, the sensing circuit 714, the excitation buffer 716, and / or the AC ground buffer 718 can be included in the touch controller 206, and in some examples, included in the sensing channel 208. In addition, the sensing circuit 714, the excitation buffer 716, and / or the AC ground buffer 718 are provided only as examples, and it should be understood that other circuits can be used to similarly drive, sense, and ground the touch nodes of the present disclosure.

[0100] Figure 7B An exemplary configuration of a partially bootstrapped touch screen 750 is shown that can utilize a switch array 752 to couple appropriate circuitry to touch nodes. Touch nodes in the touch screen 750 can be coupled to the switch array 752. The switch array 752 can include switches and / or multiplexers or other circuitry that can couple inputs to one or more outputs of the switch array. The switch array 752 can be coupled to an amplifier circuit 754 that can include circuitry such as Fig. 7A One or more sensing circuits 714, one or more excitation buffers 716, and one or more AC ground buffers 718 are shown. The amplifier circuit portion 754 can be coupled to touch processing circuits 756, such as an analog front end (AFE), an analog-to-digital converter (ADC), and demodulation circuits for processing touch signals detected on the touch screen 750.

[0101] Circuits such as sensing circuit 714, excitation buffer 716, and AC ground buffer 718 do not need to be permanently coupled to the touch nodes for proper touch screen operation. Instead, such circuits can be coupled to the touch nodes through switch array 752 so that the appropriate touch nodes can be coupled to the appropriate circuits only when needed. This can allow multiple touch nodes to share common circuits, which in turn can reduce the number of circuits required for touch screen operation. For example, switch array 752 can be used to couple a first touch node (first DS touch node) to be driven and sensed to sensing circuit 714. When a second touch node (second DS touch node) is to be driven and sensed, the switch array can couple the same sensing circuit 714 to the second touch node to drive and sense the second touch node instead of the first touch node. The operation of such switch array 752 can be similarly applied to coupling excitation buffer 716, AC ground buffer 718, and any other appropriate circuits to the appropriate touch nodes. Switch array 752 can be any suitable switch network that can couple a touch node to an appropriate circuit in amplifier circuit portion 754.

[0102] In some examples, the touch nodes on the touch screen 750 can be stimulated in a single excitation configuration, as generally described in the present disclosure (e.g., a single sensing circuit 714 in the amplifier circuit portion 754 can stimulate and sense a single touch node at any time). In some examples, the touch screen scanning of the present disclosure can be extended to a multi-excitation type implementation, where the touch nodes on the touch screen 750 can be stimulated in a multi-excitation configuration (e.g., a single sensing circuit 714 in the amplifier circuit portion 754 can stimulate and sense multiple touch nodes at any time). In the multi-excitation configuration, any suitable multi-excitation scheme can be used, and the switch array 752 can be used as appropriate to implement the multi-excitation scheme. For example, a Hadamard / circular matrix drive and sense scheme with receive-side encoding can be utilized, where, except for the common-mode touch scanning step, for each touch scanning step, the touch nodes receiving the positive phase excitation signal and the touch nodes receiving the negative phase excitation signal can be identical.

[0103] like Figure 5B , Figure 6B and Fig. 7A As shown in FIG. 1 , in a partial bootstrap scanning configuration, only one touch node out of every four touch nodes can be driven and sensed at any one time. Therefore, only one quarter of the total self-capacitive touch image can be captured. In addition, as Figure 6CAs shown, at any one time, only one pair of touch nodes associated with every four touch nodes can be sensed. Therefore, only half of the total mutual capacitance touch image can be captured. As such, it is beneficial to drive, sense, and / or ground each touch node at a certain point in time in order to capture a complete self-capacitance and / or mutual capacitance touch image on the touch screen. Various self-capacitance and mutual capacitance scanning schemes are described below. It should be noted that the examples of the present disclosure can be extended to other partial bootstrap, full bootstrap, and mutual capacitance schemes in which different numbers and arrangements of touch nodes can be driven and sensed, driven but not sensed, sensed, and grounded; however, for ease of description, the examples of the present disclosure will focus on configurations with four touch nodes.

[0104] As described above, isolated water drops (i.e., water drops that are not in contact with a grounded user or object) on the touch screen of the present disclosure may not appear on a full bootstrap scan of the touch screen, but may appear on a partial bootstrap scan and a mutual capacitance scan of the touch screen to varying degrees. Therefore, the comparison results of the full bootstrap scan of the touch screen and the partial bootstrap and / or mutual capacitance scan of the touch screen can be used to identify the presence of water on the touch screen, and ignore or discard the water from the final touch image that can be used to analyze the touch activity. It should be understood that the water detection and water rejection scheme of the present disclosure is applicable to isolated water drops that may exist on the touch screen, but not to water drops that may, for example, contact a user's finger.

[0105] Fig. 8A An exemplary full bootstrap scan on touch screen 800 is shown according to examples of the present disclosure. Fig. 8A The full bootstrap scan shown can be substantially similar to Figure 5A and Fig. 6A As described above, due to the full bootstrap scan shown (the touch activity will be attenuated when the user is not grounded or poorly grounded), the touch activity on the touch screen 800 can be sensed, but water will not be sensed. Therefore, Fig. 8A A fully bootstrapped scan of can provide a touch image that includes touch activity but does not include water, with a resolution of 4×4 touch nodes (each touch node 802 can be independently driven and sensed, whether simultaneously or otherwise).

[0106] Figure 8B An exemplary partial bootstrap scan on touch screen 800 is shown according to examples of the present disclosure. Figure 8B The partial bootstrap scan shown can be substantially similar to Figure 5B and Figure 6BPartial bootstrap scan as shown. In some examples, the partial bootstrap scan can be performed in at least four steps, during which different touch nodes 802 in a group of four touch nodes can be driven and sensed, driven but not sensed, and grounded. Specifically, in the first step 804, the upper left touch node 802 can be driven and sensed, the lower right touch node can be grounded, and the remaining two touch nodes (lower left and upper right) can be driven but not sensed. As shown, the second step 806, the third step 808, and the fourth step 810 steps can cause touch nodes in different arrangements to be driven and sensed, driven but not sensed, and grounded, so that at the end of the fourth step, all touch nodes in the group of four touch nodes have been driven and sensed at some point in time. The order of scanning steps provided is exemplary only, and it should be understood that different orders of scanning steps can be utilized.

[0107] As described above, since water that may be present on the touch screen 800 may be reflected in a partial bootstrap scan of the touch screen, Figure 8B The partial bootstrap scan of can generate a touch image including touch activity and water, which has a resolution of 4×4 touch nodes. The touch image can be compared with Fig. 8A The touch image captured in the image (which may include touch activity but not water) is compared to determine whether water exists on the touch screen 800 and determine the location where water may exist. Then, when analyzing the touch on the touch screen, the portion of the touch image associated with water may be discarded or ignored.

[0108] In some examples, to save time and / or reduce usage of resources (e.g., sensing circuitry), the resolution of a full bootstrap scan of the touch screen can be reduced for water detection and water rejection purposes when high resolution water rejection is not required (e.g., if water detection at the touch node electrode level is not required). Figure 8C An exemplary full bootstrap scan with reduced resolution on touch screen 800 is shown according to an example of the present disclosure. Figure 8C In a scan of , a group of four touch nodes can be driven and sensed by the same sensing circuit, rather than each touch node 802 being driven and sensed individually by a respective sensing circuit (whether simultaneously or otherwise). Fig. 8A This can reduce the amount of sensing circuitry required and / or can reduce the amount of time required to scan the entire touch screen 800, since a larger portion of the touch screen can be driven and sensed at a time, compared to a single scan. However, as a result, the resolution of the resulting touch image can be reduced to 2×2 "composite touch nodes" (2×2 groups of touch nodes). This reduced resolution touch image can be compared to, for example, Figure 8BThe touch image acquired by the partial bootstrap scan is compared to determine whether water is present on the touch screen 800 and the location where water may be present as described above, and then when analyzing the touch on the touch screen, the portion of the touch image associated with water can be discarded or ignored, although at a lower resolution than before.

[0109] Figure 8A-8C A water detection and water rejection scheme is described in which a full bootstrap touch scan is compared to a partial bootstrap touch scan to determine the presence and / or location of water on the touch screen. In some examples, an alternative water detection and water rejection scheme may be used that may be based on a full bootstrap touch scan and a mutual capacitance scan.

[0110] Fig. 9A An exemplary full bootstrap scan on touch screen 900 is shown according to examples of the present disclosure. Fig. 9A The scan can be Fig. 8A The scans are the same, and the details are omitted here for brevity.

[0111] Fig. 9B An exemplary mutual capacitance scan on a touch screen 900 is shown according to examples of the present disclosure. Fig. 9B The mutual capacitance scan shown is basically similar to Figure 6C The mutual capacitance scan shown. In some examples, the mutual capacitance scan can be performed in at least two steps, during which different touch nodes 902 in a group of four touch nodes can be driven, sensed, and grounded, as described above. Specifically, in the first step 904, the upper left touch node 902 can be driven, the lower right touch node can be sensed, and the remaining two touch nodes (lower left and upper right) can be grounded. As shown, the second step 906 can cause touch nodes in different arrangements to be driven, sensed, and grounded, so that at the end of the second step, the mutual capacitance of two pairs of touch nodes in the group of four touch nodes has been sensed at a certain point in time. The order of scanning steps and specific configurations provided is merely exemplary, and it should be understood that different orders of scanning steps can be utilized.

[0112] As described above, since water that may exist on the touch screen 900 may be reflected in the mutual capacitance scan of the touch screen, Fig. 9B The mutual capacitance scan of the touch sensor can generate a touch image that includes touch activity and water. Fig. 9A The touch image captured in the image (which may include touch activity but not water) is compared to determine whether water exists on the touch screen 900 and determine the location where water may exist. Then, when analyzing the touch on the touch screen, the portion of the touch image associated with water may be discarded or ignored.

[0113] As previously described, in some examples, in order to save time and / or reduce the use of resources (e.g., sensing circuitry), when high-resolution water rejection is not required (e.g., if water detection at the touch node electrode level is not required), the resolution of the full bootstrap scan of the touch screen can be reduced for water detection and water rejection purposes. Fig. 9C An exemplary full bootstrap scan with reduced resolution on touch screen 900 is shown according to examples of the present disclosure. Fig. 9C The scans and resulting water detection and water rejection schemes can be similar to those of reference Figure 8C For the sake of brevity, the details of what has been described will not be repeated.

[0114] Various touch screen display frame and touch frame configurations will now be described in which the Figure 8A-8C and Figure 9A-9C The configurations provided are exemplary only, and it should be understood that other configurations based on similar principles may be used and achieve similar results.

[0115] Fig. 10A An exemplary basic touch screen display frame and touch frame configuration 1000 is shown according to an example of the present disclosure. Display frame 1002 may be a duration during which a display portion of a touch screen of the present disclosure may be updated. Display frame 1002 may include two touch frames, namely touch frame 1004 and touch frame 1006, during which touch activity on all portions of the touch screen may be detected (e.g., touch activity may be scanned at a faster rate than the display is updated - in some examples, at twice the rate). In other words, in some examples, touch frame 1004 may be a first duration during which touch activity on all portions of the touch screen may be detected, and touch frame 1006 may be a second duration during which touch activity on all portions of the touch screen may be detected. The one-to-two relationship of display frame 1002 to touch frames 1004 and 1006 is provided by way of example only, and it should be understood that for Fig. 10A For the example of and all examples of the present disclosure, other ratios of display frames to touch frames may be used.

[0116] The touch frame 1004 may include scanning steps MC1 1008 and MC2 1014. MC1 1008 and MC2 1014 may correspond to Fig. 9B 1004 and 1006. As described above, in some examples, MC1 1008 and MC2 1014 may be used to correct for attenuation of ungrounded user touch signals and / or water detection and water rejection.

[0117] In touch frame 1004, MC1 1008 and MC2 1014 can be separated by PB1 1010 and PB2 1012. PB1 1010 and PB2 1012 can correspond to partial bootstrap scan steps 804, 806, 808, and 810 performed in different areas of the touch screen. In other words, PB1 1010 can correspond to a partial bootstrap scan step performed in a first area of ​​the touch screen, and PB2 1012 can correspond to a partial bootstrap scan step performed in a second area of ​​the touch screen. Similarly, PB3 1016 and PB4 1018 can correspond to partial bootstrap scan steps performed in a third area and a fourth area of ​​the touch screen, respectively. PB1 1010, PB2 1012, PB3 1016, and PB4 1018 together can provide a complete partial bootstrap touch image on the touch screen. The details of PB1 1010, PB2 1012, PB3 1016, and PB4 1018 will be described in more detail below. As described above, in some examples, PB1 1010, PB2 1012, PB3 1016, and PB4 1018 can be used to acquire a touch image on the touch screen and / or correct for attenuation of an ungrounded user touch signal. Touch frame 1006 can be the same as touch frame 1004.

[0118] Fig. 10B Shows Fig. 10A 1020. In some examples, the amount of sensing circuitry required to scan the touch screen of the present disclosure can be reduced by scanning portions of the touch screen one by one rather than scanning all portions of the touch screen at once, as will be described in more detail below. During PB1 1010, a first portion 1011 (e.g., the first quarter) of the touch screen can be scanned using a partial bootstrap scanning scheme. As part of this scan, the touch electrodes of the first portion 1011 of the touch screen can be scanned in a configuration shown in pattern 1020 (similar to the configuration of reference 1020). Figure 8C The remainder of the touch screen may be driven in the configuration shown in pattern 1022, which may correspond to the configuration shown in pattern 1020. The scanning configuration in pattern 1022 may be the same as the scanning configuration in pattern 1020, with the only difference being that the DS touch node electrodes in pattern 1020 may be driven but not sensed in pattern 1022 (i.e., the DS touch node electrodes may become D touch node electrodes).

[0119] The details of scanning steps PB2 1012, PB3 1016, and PB4 1018 may be similar to the details of PB1 1010, and for the sake of brevity, their details will not be repeated. PB1 1010, PB2 1012, PB3 1016, and PB4 1018 together can provide a partial bootstrapped touch image of the entire touch screen. It will be appreciated that in some examples, a partial bootstrapped touch image of the entire touch screen may be acquired with fewer or more scans than presented here (e.g., the entire touch screen may be scanned simultaneously according to pattern 1020); however, scanning only portions of the touch screen at a given time may reduce the amount of sensing circuitry required. Examples of the present disclosure will generally be provided assuming that portions of the touch screen are scanned, but the scope of the present disclosure is not limited in this regard.

[0120] Fig.11A An exemplary water detection and water repellency display frame and touch frame configuration 1100 is shown according to an example of the present disclosure. Similar to the foregoing, display frame 1102 may include two touch frames 1104 and 1106. Touch frame 1104 may be substantially similar to Fig. 10A 1004, except that touch frame 1104 may additionally include a scanning step FB 1120 preceding scanning steps MC11108 and MC2 1114. FB 1120 may correspond to Fig. 8A , Figure 8C , Fig. 9A or Fig. 9C PB1 1110, PB2 1112, PB3 1116, PB4 1118, MC1 1108, and MC2 1114 may correspond to Fig. 10A PB1 1010, PB2 1012, PB3 1016, PB4 1018, MC1 1008 and MC2 1014.

[0121] FB 1120 may provide a fully bootstrapped touch image of the entire touch screen. In some examples, such a fully bootstrapped touch image may be full resolution (either sensed all at once or sensed portion by portion), or may be reduced resolution as previously described, which may be applicable to one or more example scanning configurations described in the present disclosure. As described above, the partial bootstrapped touch images from PB1 1110, PB2 1112, PB3 1116, and PB4 1118 may be compared to the fully bootstrapped touch image from FB 1120 to detect and exclude water. In some examples, the fully bootstrapped touch image from FB 1120 may be compared to less than all of PB1 1110, PB2 1112, PB3 1116, and PB4 1118, so that water may be detected and excluded for one or more touch screen portions at a time. For example, FB 1120 in portion 1124 of touch frame 1104 may be compared to PB2 1112 and PB3 1116 in portion 1124 of touch frame 1104 to detect and exclude water from the portion of the touch screen corresponding to scan steps PB2 and PB3. Similarly, FB 1120 in portion 1126 of touch frames 1104 and 1106 may be compared to PB4 1118 and PB1 1110 in portion 1126 of touch frames 1104 and 1106 to detect and exclude water from the portion of the touch screen corresponding to scan steps PB4 and PB1. Other portions of the touch frame (e.g., portions 1122, 1128, and 1130) may be operated similarly to those described above.

[0122] One advantage of assigning FB 1120 to various locations within a touch frame and detecting and rejecting water within portions of the touch frame may be that changes in the touch image (e.g., due to a moving finger or moving water) during the water detection and water rejection cycle may be minimized, as such changes in the touch image may adversely affect proper water detection and water rejection because it is more difficult to accurately align various types of touch images (e.g., a fully bootstrapped touch image and a mutual capacitance touch image, or a fully bootstrapped touch image and a partially bootstrapped touch image) when comparing touch images.

[0123] In some examples, MC1 1108 and MC2 1114 can be combined with FB 1120 in a manner similar to that described above for water detection and water repellency, and / or for other purposes such as correcting for attenuation of ungrounded user touch signals. Alternatively, in some examples, MC1 1108 and / or MC2 1114 can be removed from touch frames 1104 and 1106. In some examples, swapping the order of FB 1120 and MC1 1108 / MC2 1114 can achieve substantially the same results. This swapping of the scanning order can be similarly applied to one or more other examples of the present disclosure.

[0124] Fig. 11B Another exemplary water detection and water repelling display frame and touch frame configuration 1101 according to examples of the present disclosure is shown. Similar to the foregoing, display frame 1102 may include two touch frames 1104 and 1106. Touch frames 1104 and 1106 in configuration 1101 may be substantially similar to Fig.11A The touch frames 1104 and 1106 in the configuration 1100 are different in that Fig. 11B In the configuration 1101 in FIG. 1 , the FB 1120 in the configuration 1100 may be divided into FB1 1132 , FB2 1134 , FB3 1136 , and FB4 1138 .

[0125] Specifically, FB1 1132 may precede PB1 1110 in touch frame 1104. FB1 1132 may correspond to Fig. 8A , Figure 8C , Fig. 9A or Fig. 9C The full bootstrap scanning step performed in the first area of ​​the touch screen shown is similar to the way PB11110 corresponds to the partial bootstrap scanning step performed in the first area of ​​the touch screen, as described above. Fig. 11C Describe the details of FB1 1132.

[0126] FB1 1132 may provide a fully bootstrapped touch image in a first region of the touch screen, and PB1 1110 may provide a partially bootstrapped touch image in the first region of the touch screen. Thus, in region 1140 of touch frame 1104, water detection and water rejection may be performed in a first portion of the touch screen using FB1 1132 and PB1 1110. FB2 1134, FB3 1136, and FB4 1138 and corresponding PB2 1112, PB3 1116, and PB4 1118 may similarly be used to perform water detection and water rejection in a second region, a third region, and a fourth region of the touch screen, respectively. As previously described, one advantage of assigning FB1 1132, FB2 1134, FB3 1136, and FB4 1138 to various locations within a touch frame and to detecting and rejecting water within corresponding portions of the touch screen may be that changes in the touch image (e.g., due to a moving finger or moving water) during the water detection and water rejection cycle may be minimized, as such changes in the touch image may adversely affect proper water detection and water rejection (e.g., a fully bootstrapped touch image and a mutual capacitance touch image, or a fully bootstrapped touch image and a partially bootstrapped touch image) because it is more difficult to accurately align various types of touch images when comparing touch images.

[0127] In some examples, MC1 1108 and MC2 1114 can be combined with FB1 1132, FB2 1134, FB3 1136, and FB4 1138 in a manner similar to that described above for water detection and water repellency, and / or for other purposes such as correcting for ungrounded user touch signal attenuation. Alternatively, in some examples, MC1 1108 and / or MC2 1114 can be removed from touch frames 1104 and 1106.

[0128] Fig. 11C Shows Fig. 11B During FB1 1132, a first portion 1111 (eg, first quarter) of the touch screen may be scanned using a fully bootstrapped scanning scheme. Although it should be understood that reference may be made to Fig. 8A and Fig. 9A The touch node electrodes of the first portion of the touch screen are scanned as described above, but as part of the scanning, the touch electrodes of the first portion 1111 of the touch screen can be scanned in the configuration shown in pattern 1148 (similar to Figure 8C and Fig. 9C The rest of the touch screen may be driven in the configuration shown in pattern 1149. The scanning configuration in pattern 1149 may be the same as the scanning configuration in pattern 1148, with the only difference being that the DS touch node electrodes in pattern 1148 may be driven but not sensed in pattern 1149 (i.e., the DS touch node electrodes may become D touch node electrodes).

[0129] The details of scanning steps FB2 1134, FB3 1136, and FB4 1138 may be similar to the details of FB1 1132 and will not be repeated for the sake of brevity. FB1 1132, FB2 1134, FB3 1134, and FB4 1138 together may provide a fully bootstrapped touch image of the entire touch screen. It will be appreciated that in some examples, a fully bootstrapped touch image of the entire touch screen may be acquired with fewer or more scans than presented here (e.g., the entire touch screen may be scanned simultaneously according to pattern 1148); however, scanning only portions of the touch screen at a given time may reduce the amount of sensing circuitry required. Examples of the present disclosure will generally be provided assuming that portions of the touch screen are scanned, but the scope of the present disclosure is not limited in this regard.

[0130] Fig.11D Shown with Fig.11A1104. At 1152, process 1150 may begin with a full bootstrap scan of the touch screen (e.g., FB 1120). At 1154, a first mutual capacitance scan of the touch screen (e.g., MC1 1108) may be performed. At 1156, it may be determined whether process 1150 is at the beginning of a touch frame (e.g., touch frame 1104). In some examples, this may be determined by checking whether one or two full bootstrap scans (e.g., FB 1120) of the touch screen have occurred, and if so, the answer to q of 1156 may be "yes", and if so, the answer to 1156 may be "no". If process 1150 is at the beginning of a touch frame, a first partial bootstrap scan of the touch screen (e.g., PB1 1110) may be performed at 1158. At 1160, a second partial bootstrap scan of the touch screen (e.g., PB2 1112) may be performed. At 1162, a full bootstrap scan of the touch screen can be performed (eg, FB 1120). At 1164, a second mutual capacitance scan of the touch screen can be performed (eg, MC2 1114).

[0131] If at 1156, process 1150 is not at the beginning of a touch frame, a third partial bootstrap scan of the touch screen (e.g., PB3 1116) can be performed at 1166. At 1168, a fourth partial bootstrap scan of the touch screen (e.g., PB4 1118) can be performed.

[0132] At 1170, a noise floor can be subtracted from the total partial bootstrap touch images acquired from the first partial bootstrap scan, the second partial bootstrap scan, the third partial bootstrap scan, and the fourth partial bootstrap scan of the touch screen. Step 1170 can include subtracting any baseline touch measurements (e.g., a baseline partial bootstrap touch image, a baseline mutual capacitance touch image, etc.) that may be stored from a previous scan.

[0133] At 1172, the touch screen may be checked for the presence of water. Specifically, if the partial bootstrap scan of the touch screen includes portions of the touch image that are not included in the full bootstrap scan of the touch screen, those portions of the touch image may be attributed to water present on the touch screen. The portions of the partial bootstrap touch image attributed to water may be removed from the original partial bootstrap touch image to provide a water-repelling partial bootstrap touch image, and the portions of the partial bootstrap touch image attributed to water may also be removed from the original mutual capacitance touch image to provide a water-repelling mutual capacitance touch image. Ungrounded user compensation may be performed on the original partial bootstrap touch image using the water-repelling partial bootstrap touch image and the water-repelling mutual capacitance touch image to provide a compensated partial bootstrap touch image.

[0134] At 1174, the compensated partial bootstrapped touch image can be analyzed to determine if there is touch activity in the touch image (whether due to water or due to an actual touch). If there is no touch activity, then at 1176 it can be determined that there is no touch and no water on the touch screen, and the measured partial bootstrapped touch image and mutual capacitance touch image described above can be captured / stored to be used as baseline measurements in subsequent scans.

[0135] If there is touch activity in the compensated partial bootstrapped touch image at 1174, then it may be determined whether the full bootstrapped touch image contains touch activity at 1178. If there is no touch activity, then it may be determined at 1180 that there is no actual touch on the touch screen, but there is water on the touch screen. The partial bootstrapped touch image and mutual capacitance touch image measured above may be captured / stored for use as baseline measurements, which may be used as a benchmark to measure the effect of water in subsequent scans.

[0136] If at 1178, touch activity is present in the full bootstrap touch image, then it may be determined that actual touch activity and water are present on the touch screen at 1182. Touch activity due to water may be excluded from the compensated partial bootstrap touch image by comparing the full bootstrap touch image with the compensated partial bootstrap touch image, as described in the present disclosure, and may result in water-repelling touch activity, which the system may utilize to perform touch-related functions.

[0137] Fig.11E Shown with Fig. 11B 1108 . At 1153, process 1151 may start with a first mutual capacitance scan of the touch screen (e.g., MC1 1108). At 1155, it may be determined whether process 1151 is at the beginning of a touch frame (e.g., touch frame 1104). In some examples, this may be determined by checking whether one or two mutual capacitance scans (e.g., MC1 1108, MC2 1114) have occurred on the touch screen, and if so, the answer to 1155 may be "yes", and if so, the answer to 1155 may be "no". If process 1151 is at the beginning of a touch frame, a first full bootstrap scan of the touch screen (e.g., FB1 1132) may be performed at 1157. At 1159, a first partial bootstrap scan of the touch screen (e.g., PB1 1110) may be performed. At 1161, a second full bootstrap scan of the touch screen (e.g., FB2 1134) may be performed. At 1163, a second partial bootstrap scan of the touch screen can be performed (eg, PB2 1112). At 1165, a second mutual capacitance scan of the touch screen can be performed (eg, MC2 1114).

[0138] If at 1155, process 1151 is not at the start of a touch frame, a third full bootstrap scan of the touch screen (e.g., FB3 1136) may be performed at 1167. At 1169, a third partial bootstrap scan of the touch screen (e.g., PB3 1116) may be performed. At 1171, a fourth full bootstrap scan of the touch screen (e.g., FB4 1138) may be performed. At 1173, a fourth partial bootstrap scan of the touch screen (e.g., PB4 1118) may be performed.

[0139] At 1175, a noise floor can be subtracted from the total partial bootstrap touch image acquired from the first partial and / or full bootstrap scan, the second partial and / or full bootstrap scan, the third partial and / or full bootstrap scan, and the fourth partial and / or full bootstrap scan of the touch screen. Step 1175 can include subtracting any baseline touch measurements (e.g., a baseline partial bootstrap touch image, a baseline mutual capacitance touch image, etc., a baseline full bootstrap touch image, etc.) that may be stored from a previous scan.

[0140] At 1177, the touch screen may be checked for the presence of water. Specifically, if the partial bootstrap scan of the touch screen includes portions of the touch image that are not included in the full bootstrap scan of the touch screen, those portions of the touch image may be attributed to water present on the touch screen. The portions of the partial bootstrap touch image attributed to water may be removed from the original partial bootstrap touch image to provide a water-repelling partial bootstrap touch image, and the portions of the partial bootstrap touch image attributed to water may also be removed from the original mutual capacitance touch image to provide a water-repelling mutual capacitance touch image. Ungrounded user compensation may be performed on the original partial bootstrap touch image using the water-repelling partial bootstrap touch image and the water-repelling mutual capacitance touch image to provide a compensated partial bootstrap touch image.

[0141] At 1179, the compensated partial bootstrapped touch image may be analyzed to determine if there is touch activity in the touch image (whether due to water or due to an actual touch). If there is no touch activity, then at 1181, it may be determined that there is no touch and no water on the touch screen, and the partial bootstrapped touch image, the measured mutual capacitance touch image described above, and the full bootstrapped touch image may be captured / stored to be used as a baseline measurement in subsequent scans.

[0142] If there is touch activity in the compensated partial bootstrap touch image at 1179, it may be determined whether the full bootstrap touch image contains touch activity at 1183. If there is no touch activity, it may be determined that there is no actual touch on the touch screen, but there is water on the touch screen at 1185. The partial bootstrap touch image and mutual capacitance touch image measured above may be captured / stored for use as baseline measurements, which may be used as a benchmark to measure the effect of water in subsequent scans.

[0143] If touch activity is present in the full bootstrap touch image at 1183, then it may be determined that actual touch activity and water are present on the touch screen at 1187. Touch activity due to water may be excluded from the compensated partial bootstrap touch image by comparing the full bootstrap touch image with the compensated partial bootstrap touch image, as described in the present disclosure, and may result in water-repelling touch activity, which the system may utilize to perform touch-related functions.

[0144] Fig. 12A An exemplary water detection and water repelling display frame and touch frame configuration 1200 is shown according to an example of the present disclosure. The water detection and water repelling display frame and touch frame configuration 1200 may include Fig.11A The water detection and water repellency display frame and touch frame configuration 1100 have the same scanning steps in the same scanning order. For example, similar to Fig.11A FB 1220 may correspond to Fig. 8A , Figure 8C , Fig. 9A or Fig. 9C The fully bootstrapped scanning steps are shown. However, in Fig.11A In FIG. 1 , the full bootstrap scan FB1120 is used in combination with (eg, compared to) the partial bootstrap scans PB1 1110, PB2 1112, PB3 1116, and PB4 1118 to perform water detection and water rejection. Fig. 12A In the embodiment of the present disclosure, the full bootstrap scan FB 1220 may be used in combination with (eg, compared to) the mutual capacitance scans MC1 1208 and MC2 1214 to perform water detection and water rejection as described in the present disclosure.

[0145] One advantage of using FB 1220 with adjacently disposed MC1 1208 and / or MC2 1214 to perform water rejection may be that changes in the touch image (e.g., due to a moving finger or moving water) during the water detection and water rejection period may be minimized, such changes in the touch image may adversely affect proper water detection and water rejection (e.g., a fully bootstrapped touch image and a mutual capacitance touch image, or a fully bootstrapped touch image and a partially bootstrapped touch image) because it is more difficult to accurately align various types of touch images when comparing touch images. For example, FB 1220 may be used with adjacently disposed MC1 1208 to perform water detection and water rejection, and another FB 1220 may be used with adjacently disposed MC2 1214 to perform further water detection and water rejection. In some examples, both MC1 1208 and MC2 1214 are performed before water detection and water rejection are initiated for a touch frame.

[0146] In some examples, MC1 1208 and MC2 1214 may additionally or alternatively be used for purposes other than water detection and water repellency; for example, in some examples, MC1 and MC2 may be used to correct for ungrounded user touch signal attenuation.

[0147] Fig. 12B Shows Fig. 12A As described above, in some examples, the full bootstrap scan step (e.g., FB 1220) of the present disclosure may be a full resolution scan (e.g., Fig. 8A However, in some examples, the fully bootstrapped scanning step (e.g., FB 1220) of the present disclosure may be a process in which multiple touch node electrodes are sensed by the same sensing circuit (e.g., Figure 8C In some examples, during the full bootstrap scan step (e.g., FB 1220) of the present disclosure, a 4×4 touch node electrode group can be driven and sensed by the same circuit.

[0148] In these examples, the corresponding mutual capacitance scanning steps (e.g., MC1 1208 and MC2 1214) can be similarly performed at reduced resolutions so that when performing water detection and water rejection, the resolutions of the fully bootstrapped touch image and the mutual capacitance touch image can substantially correspond (e.g., the reduced resolution fully bootstrapped touch image can be a 2×2 touch node image, and the reduced resolution mutual capacitance touch image can be a 2×2 touch node image with common sense touch values). Specifically, for example, during MC1 1208, multiple touch node electrodes in a 4×4 touch node electrode group can be sensed by the same sense amplifier 1205, as shown in configuration 1201. Similarly, during MC2 1214, multiple touch node electrodes in a 4×4 touch node electrode group can be sensed by the same sense amplifier 1205, as shown in configuration 1203. In this way, reduced resolution mutual capacitance touch images can be captured on the touch screen that substantially correspond to the resolution of the reduced resolution fully bootstrapped touch images that can be captured on the touch screen. It should be understood that the above-described grouping of 4×4 touch electrodes is merely exemplary, and other group arrangements and drive, sense, and ground configurations may similarly be utilized to achieve similar results.

[0149] Fig. 12C Shown with Fig. 12A1204. At 1252, process 1250 can begin with a full bootstrap scan of the touch screen (e.g., FB 1220). At 1254, a first mutual capacitance scan of the touch screen (e.g., MC1 1208) can be performed. At 1256, it can be determined whether process 1250 is at the beginning of a touch frame (e.g., touch frame 1204). In some examples, this can be determined by checking whether one or two full bootstrap scans (e.g., FB 1220) of the touch screen have occurred, and if so, the answer to 1256 can be "yes", and if so, the answer to 1256 can be "no". If process 1250 is at the beginning of a touch frame, a first partial bootstrap scan of the touch screen (e.g., PB1 1210) can be performed at 1258. At 1260, a second partial bootstrap scan of the touch screen (e.g., PB2 1212) can be performed. At 1262, a full bootstrap scan of the touch screen can be performed (eg, FB 1220). At 1264, a second mutual capacitance scan of the touch screen can be performed (eg, MC2 1214).

[0150] If at 1256, process 1250 is not at the start of a touch frame, a third partial bootstrap scan of the touch screen (e.g., PB3 1216) can be performed at 1266. At 1268, a fourth partial bootstrap scan of the touch screen (e.g., PB4 1218) can be performed.

[0151] At 1270, a noise floor can be subtracted from the total partial bootstrap touch images acquired from the first partial bootstrap scan, the second partial bootstrap scan, the third partial bootstrap scan, and the fourth partial bootstrap scan of the touch screen. Step 1270 can include subtracting any baseline touch measurements (e.g., a baseline partial bootstrap touch image, a baseline mutual capacitance touch image, etc.) that may be stored from a previous scan.

[0152] At 1272, the touch screen may be checked for the presence of water. Specifically, if the mutual capacitance scan of the touch screen includes portions of the touch image that are not included in the full bootstrap scan of the touch screen, those portions of the touch image may be attributed to the presence of water on the touch screen. The portions of the mutual capacitance touch image attributed to water may be removed from the original partial bootstrap touch image to provide a water-repelling partial bootstrap touch image, and the portions of the mutual capacitance touch image attributed to water may also be removed from the original mutual capacitance touch image to provide a water-repelling mutual capacitance touch image. Ungrounded user compensation may be performed on the original partial bootstrap touch image using the water-repelling partial bootstrap touch image and the water-repelling mutual capacitance touch image to provide a compensated partial bootstrap touch image.

[0153] At 1274, the compensated partial bootstrapped touch image can be analyzed to determine if there is touch activity in the touch image (whether due to water or due to an actual touch). If there is no touch activity, then at 1276 it can be determined that there is no touch and no water on the touch screen, and the measured partial bootstrapped touch image and mutual capacitance touch image described above can be captured / stored to be used as baseline measurements in subsequent scans.

[0154] If there is touch activity in the compensated partial bootstrap touch image at 1274, it may be determined whether the full bootstrap touch image contains touch activity at 1278. If there is no touch activity, it may be determined that there is no actual touch on the touch screen, but there is water on the touch screen at 1280. The partial bootstrap touch image and mutual capacitance touch image measured above may be captured / stored for use as baseline measurements, which may be used as a benchmark to measure the effect of water in subsequent scans.

[0155] If touch activity is present in the full bootstrap touch image at 1278, then it may be determined that actual touch activity and water are present on the touch screen at 1282. Touch activity due to water may be excluded from the compensated partial bootstrap touch image by comparing the mutual capacitance touch image and the full bootstrap touch image, as described in the present disclosure, and may result in water-repelling touch activity, which the system may utilize to perform touch-related functions.

[0156] For example, in some examples, the scanning steps in touch frames and display frames of a touch screen can be dynamically determined in response to water or touch activity. Fig.13A An exemplary dynamic water detection and water repellency display frame and touch frame configuration 1300 in a ready mode according to an example of the present disclosure is shown. Configuration 1300 may correspond to a ready mode of a touch screen. During the ready mode, touch frames 1304 and 1306 may include a full bootstrap scan step FB 1320, as well as a first mutual capacitance scan step MC1 1308 and a second mutual capacitance scan step MC2 1314.

[0157] The touch screen may remain in the ready mode until an actual touch is detected on the touch screen. As previously described, an actual touch on the touch screen may appear on both the fully bootstrapped touch image (e.g., from FB 1320) and the mutual capacitance touch image (e.g., from MC1 1308 and MC2 1314), while water may only appear on the mutual capacitance touch image. Therefore, in the ready mode, the touch screen may distinguish between an actual touch and water, and may remain in the ready mode until an actual touch is detected on the touch screen. In some examples, one of MC1 1308 and MC2 1314 may not be necessary and may be removed from the touch frames 1304 and 1306, since only one of MC1 and MC2 may be needed to determine whether water is on the touch screen, so power may be saved by removing one of MC1 and MC2 from the touch frame. In some examples, both MC1 and MC2 may be removed from the touch frame and whether an actual touch is on the touch screen may be determined based solely on the FB (which may automatically repel water on the touch screen, as described above).

[0158] When an actual touch is detected on the touch screen, the touch screen may transition to an active mode. Fig. 13B An exemplary dynamic water detection and water repelling display frame and touch frame configuration 1301 in active mode according to an example of the present disclosure is shown. In active mode, scanning steps 1310, 1312, 1316, 1318, 1322, 1324, 1326, and 1328 may be added to touch frames 1304 and 1306 as shown. Depending on various criteria, scanning steps 1310, 1312, 1316, 1318, 1322, 1324, 1326, and 1328 may be partially bootstrapped scanning steps or fully bootstrapped scanning steps, as will be described in more detail below.

[0159] For example, if an actual touch is detected on the touch screen but no water is detected, the scanning steps 1310, 1312, 1316, 1318, 1322, 1324, 1326, and 1328 in touch frames 1304 and 1306 can all be partial bootstrap scanning steps or all be full bootstrap scanning steps. For example, the partial bootstrap scanning steps can correspond to the previously described Fig.11A and Fig. 12A For example, the full bootstrap scanning step may correspond to the previously discussed PB1, PB2, PB3, and PB4. Fig. 11B FB1, FB2, FB3 and FB4 discussed.

[0160] If an actual touch is detected on the touch screen and water is detected on the touch screen, the scanning steps 1310, 1312, 1316, and 1318 in the touch frame 1304 may be different from the scanning steps 1322, 1324, 1326, and 1328 in the touch frame 1306. Specifically, the scanning steps in one touch frame may be partial bootstrap scanning steps, while the scanning steps in another touch frame may be full bootstrap scanning steps. For example, as described above, the partial bootstrap scanning steps may correspond to the previously described scanning steps with respect to Fig.11A and Fig. 12A PB1, PB2, PB3 and PB4 discussed above, and the full bootstrap scanning step may correspond to the previous description of Fig. 11B FB1, FB2, FB3 and FB4 discussed.

[0161] In some examples, in active mode, water detection and water rejection can be performed by comparing a full bootstrapped touch image with a partial bootstrapped touch image or by comparing a full bootstrapped touch image with a mutual capacitance touch image, as described in the present disclosure. Fig.13A and 13B Exemplary dynamic water detection and water repelling display frame and touch frame constructions are shown.

[0162] Fig. 13C Shown with Fig. 13B 1350. At 1352, process 1350 can begin with a full bootstrap scan of the touch screen (e.g., FB 1320). At 1354, a first mutual capacitance scan of the touch screen (e.g., MC1 1308) can be performed. In some examples, if no touch is detected as a result of the FB and / or MC1 scans, process 1350 can return to the starting point (step 1352) and can skip subsequent scans, which will be described below, to save power; this operation of skipping subsequent scan steps to save power when no touch is detected on the touch screen at the beginning of a touch frame can be similarly applied to other figures (e.g., FIG. 11A to FIG. 14E ) and all other scan plans described in ). However, in some examples, even if no touch is detected as a result of the FB and / or MC1 scans, since the touch screen may need to capture a new baseline for use in subsequent scanning steps, process 1350 may be performed as follows. Fig. 13C Continue as shown. A new baseline may be needed based on many factors (e.g., touch screen temperature, time, etc.). The baseline capture algorithm can be similarly applied to other figures (e.g., FIG. 11A to FIG. 14E) and all other scan plans described in 1354. If the process continues after 1354 for any reason, at 1356 it can be determined whether the process 1350 is at the beginning of a touch frame (e.g., touch frame 1304). In some examples, this can be done by checking whether the touch screen has one or two mutual capacitance scans (e.g., MC1 1308, MC2 1314) occurring, and if so, the answer to 1356 can be "yes", and if so, the answer to 1356 can be "no". If the process 1350 is at the beginning of a touch frame, at 1358 a first partial bootstrap scan of the touch screen can be performed (e.g., at scan step 1310). At 1360, a second partial bootstrap scan of the touch screen can be performed (e.g., at scan step 1312). At 1364, a second mutual capacitance scan of the touch screen can be performed (e.g., MC2 1314).

[0163] If at 1356, process 1350 is not at the start of a touch frame, a third partial bootstrap scan of the touch screen (e.g., at scanning step 1316) may be performed at 1366. At 1368, a fourth partial bootstrap scan of the touch screen may be performed (e.g., at scanning step 1318).

[0164] At 1372, a noise floor can be subtracted from the total partial bootstrap touch images acquired from the first partial bootstrap scan, the second partial bootstrap scan, the third partial bootstrap scan, and the fourth partial bootstrap scan of the touch screen. Step 1372 can include subtracting any baseline touch measurements (e.g., a baseline partial bootstrap touch image, a baseline mutual capacitance touch image, etc., a baseline full bootstrap touch image, etc.) that may be stored from a previous scan.

[0165] At 1370, the touch screen may be checked for the presence of water. Specifically, if the mutual capacitance scan of the touch screen includes portions of the touch image that are not included in the full bootstrap scan of the touch screen, those portions of the touch image may be attributed to the presence of water on the touch screen. The portions of the mutual capacitance touch image attributed to water may be removed from the original partial bootstrap touch image to provide a water-repelling partial bootstrap touch image, and the portions of the mutual capacitance touch image attributed to water may also be removed from the original mutual capacitance touch image to provide a water-repelling mutual capacitance touch image. Ungrounded user compensation may be performed on the original partial bootstrap touch image using the water-repelling partial bootstrap touch image and the water-repelling mutual capacitance touch image to provide a compensated partial bootstrap touch image.

[0166] If water is not detected on the touch screen at 1370, the compensated partial bootstrapped touch image can be analyzed at 1374 to determine whether there is touch activity in the touch image (whether due to water or due to an actual touch). If there is no touch activity, it can be determined at 1376 that there is no touch and no water on the touch screen, and the measured partial bootstrapped touch image, mutual capacitance touch image, and full bootstrapped touch image described above can be captured / stored to be used as baseline measurements in subsequent scans.

[0167] If touch activity is present in the compensated partial bootstrapped touch image at 1374, then it can be determined that actual touch activity is present on the touch screen but no water is present at 1378. The touch activity can be used by the system to perform touch-related functions.

[0168] Referring back to step 1370, if water is detected on the touch screen, the touch screen may switch between performing a partial bootstrap touch scan during one touch frame (e.g., touch frame 1304) and performing a full bootstrap touch scan during the next touch frame (e.g., touch frame 1306). Specifically, at 1380, process 1350 may start with a full bootstrap scan of the touch screen (e.g., FB 1320). At 1382, a first mutual capacitance scan of the touch screen (e.g., MC1 1308) may be performed. At 1384, it may be determined whether process 1350 is at the beginning of a touch frame (e.g., touch frame 1306). In some examples, this may be determined by checking whether the touch screen has had one or two mutual capacitance scans (e.g., MC1 1308, MC2 1314) occur, and if so, the answer to 1384 may be "yes", and if so, the answer to 1384 may be "no". If process 1350 is at the beginning of a touch frame, a first full bootstrap scan of the touch screen can be performed at 1386 (e.g., at scan step 1322). At 1388, a second full bootstrap scan of the touch screen can be performed (e.g., at scan step 1324). At 1392, a second mutual capacitance scan of the touch screen can be performed (e.g., MC2 1314).

[0169] If at 1384, process 1350 is not at the beginning of a touch frame, a third full bootstrap scan of the touch screen can be performed at 1394 (e.g., at scanning step 1326). At 1396, a fourth full bootstrap scan of the touch screen can be performed (e.g., at scanning step 1328).

[0170] At 1398, a noise floor can be subtracted from the total full bootstrap touch images acquired from the first full bootstrap scan, the second full bootstrap scan, the third full bootstrap scan, and the fourth full bootstrap scan of the touch screen. Step 1398 can include subtracting any baseline touch measurements (e.g., a baseline partial bootstrap touch image, a baseline mutual capacitance touch image, etc., a baseline full bootstrap touch image, etc.) that may be stored from a previous scan.

[0171] At 1398-2, the touch screen may be checked for the presence of water. Specifically, if the partial bootstrap scan of the touch screen includes portions of the touch image that are not included in the full bootstrap scan of the touch screen, those portions of the touch image may be attributed to water present on the touch screen. The portions of the partial bootstrap touch image attributed to water may be removed from the original partial bootstrap touch image to provide a water-repelling partial bootstrap touch image, and the portions of the partial bootstrap touch image attributed to water may also be removed from the original mutual capacitance touch image to provide a water-repelling mutual capacitance touch image. Ungrounded user compensation may be performed on the original partial bootstrap touch image using the water-repelling partial bootstrap touch image and the water-repelling mutual capacitance touch image to provide a compensated partial bootstrap touch image.

[0172] The compensated partial bootstrap touch image is analyzed at 1398-4 to determine whether there is touch activity in the touch image (whether due to water or due to actual touch). If there is no touch activity, then at 1376 it can be determined that there is no touch and no water on the touch screen, and the partial bootstrap touch image, mutual capacitance touch image, and full bootstrap touch image measured above can be captured / stored to be used as baseline measurements in subsequent scans.

[0173] If there is touch activity in the compensated partial bootstrap touch image at 1398-4, it may be determined at 1398-6 whether the full bootstrap touch image contains touch activity. If there is no touch activity, it may be determined at 1398-8 that there is no actual touch on the touch screen, but there is water on the touch screen. The partial bootstrap touch image and mutual capacitance touch image measured above may be captured / stored for use as baseline measurements, which may be used to eliminate the effect of water in subsequent scans.

[0174] If there is touch activity in the compensated full bootstrap touch image at 1398-6, then at 1398-10, it can be determined that there is actual touch activity and water on the touch screen. Touch activity due to water can be excluded from the compensated partial bootstrap touch image by comparing the partial bootstrap touch image with the full bootstrap touch image, as described in the present disclosure, and can result in water-repelling touch activity, which the system can utilize to perform touch-related functions.

[0175] Fig.13D Shown with Fig. 13B Another exemplary process 1351 corresponding to the water detection and water rejection steps. Process 1351 can be used with Fig. 13C 1351, except that the partial bootstrap scans performed at 1358, 1360, 1366, and 1368 in process 1350 may be replaced by full bootstrap scans performed at 1359, 1361, 1367, and 1369, respectively, in process 1351. In addition, the full bootstrap scans performed at 1386, 1388, 1394, and 1396 in process 1350 may be replaced by partial bootstrap scans performed at 1387, 1389, 1395, and 1397, respectively, in process 1351. The remaining details of process 1351 are substantially the same as in process 1350 and will not be repeated here for the sake of brevity.

[0176] In some examples, the touch screen of the present disclosure may switch between a fully bootstrapped touch scan and a partially bootstrapped touch scan, depending on whether the user interacting with the touch screen is well grounded or poorly grounded. Specifically, the touch screen may perform a fully bootstrapped touch scan by default, since the fully bootstrapped touch scan automatically repels water (i.e., water does not appear in the fully bootstrapped touch scan). However, if the touch signal attenuation becomes excessive due to poorly grounded user interaction (e.g., if an appropriate quality factor is exceeded or not met), the touch screen may switch to performing a partially bootstrapped touch scan to offset the attenuation of the poorly grounded touch signal. In addition, the touch screen may utilize the water detection and water rejection schemes discussed in the present disclosure (e.g., comparing a fully bootstrapped touch image with a partially bootstrapped touch image and / or comparing a fully bootstrapped touch image with a mutual capacitance touch image) to detect and repel water that may appear in a partially bootstrapped touch scan.

[0177] Fig.14A An exemplary default display frame and touch frame configuration 1400 according to an example of the present disclosure is shown. As previously described, display frame 1402 may include touch frames 1404 and 1406. As described above, configuration 1400 may be primarily based on a full bootstrap scan of the touch screen, since such a scan may automatically repel water that may be present on the touch screen. Thus, touch frame 1404 may include full bootstrap scan steps FB1 1432, FB2 1434, FB3 1436, and FB4 1438. FB1 1432, FB2 1434, FB3 1436, and FB4 1438 may correspond to Fig. 11B1434, FB3 1436, and FB4 1438 described in. Touch frame 1406 may similarly include full bootstrap scan steps FB1 1432, FB2 1434, FB3 1436, and FB4 1438. Touch frames 1404 and 1406 may also include mutual capacitance scan steps MC1 1408 and MC2 1414, which may be used to perform ungrounded user compensation where appropriate. Touch activity may be determined from FB1 1432, FB2 1434, FB3 1436, and FB4 1438 and may be used by the system to perform touch-related functions.

[0178] If the attenuation of the ungrounded user touch signal becomes too great, the touch screen can transition to a partially bootstrapped mode of operation. The attenuation can be determined using any suitable metric that reflects how well the user is grounded. In some examples, a suitable metric can be a "Z density" metric, which, for a given touch, can be expressed as:

[0179] Z density = (touch amount) / (touch radius) (11)

[0180] A high Z density may reflect a well-grounded user, while a low Z density may reflect a poorly grounded user. Various Z density thresholds may be used to control whether the touch screen operates in a full bootstrap mode of operation or a partial bootstrap mode of operation, as will be described in more detail below.

[0181] Fig. 14B An exemplary display frame and touch frame configuration 1401 for touch screen operation in a partial bootstrap operation mode according to an example of the present disclosure is shown. As previously described, display frame 1402 may include touch frames 1404 and 1406. In response to detecting Fig.14A For users with poor grounding in the touch frame 1406, the full bootstrap scan steps FB1 1432, FB2 1434, FB3 1436, and FB4 1438 in configuration 1400 may become partial bootstrap scan steps PB1 1410, PB2 1412, PB3 1416, and PB4 1418 in configuration 1401. In addition, a separate full bootstrap scan step 1420 may be added to touch frame 1404. Touch frame 1406 may be substantially the same as touch frame 1404.

[0182] Thus, the touch screen can utilize the partial bootstrap scan steps PB1 1410, PB2 1412, PB3 1416, and PB4 1418 and the mutual capacitance scan steps MC1 1408 and MC2 1414 to perform touch detection, ungrounded user compensation, or both. Additionally or alternatively, the touch screen can utilize the partial bootstrap scan steps PB1 1410, PB2 1412, PB3 1416, and PB4 1418, the mutual capacitance scan steps MC1 1408 and MC2 1414, and / or the full bootstrap scan step 1420 to perform water detection and water rejection, as discussed in the present disclosure. Specifically, the touch screen can utilize a comparison of the full bootstrap touch image with the partial bootstrap touch image and / or a comparison of the full bootstrap touch image with the mutual capacitance touch image to detect and reject water that may be present in a partial bootstrap touch scan of the touch screen.

[0183] Fig. 14C 1440 is an exemplary condition that enables the touch screen of the present invention to switch between full bootstrap operation and partial bootstrap operation according to an example of the present disclosure. As previously described, the touch screen can start in full bootstrap operation mode 1441. The full bootstrap operation mode may correspond to Fig.14A The scanning step in configuration 1400 in FIG.

[0184] When no touch is detected on the touch screen, the touch screen can remain in the full bootstrap mode of operation 1441 via 1444. In some examples, the absence of a touch on the touch screen can be indicated by a Z density of the detected touch image (after compensating the touch image for ungrounded user touch signal attenuation) being less than a second threshold.

[0185] In addition, when a grounded user (grounded touch) is detected on the touch screen, the touch screen can remain in the full bootstrap operation mode 1441 via 1443. In some examples, the grounded user can be represented by a Z density greater than a first threshold of the touch image detected before ungrounded user compensation and a Z density greater than a second threshold of the touch image detected after ungrounded user compensation. In the above and below discussions, the first threshold can correspond to a touch that can be identified as a touch even before compensating for the ungrounded user effect (e.g., a strong touch signal). The second threshold can correspond to a touch that will be identified as a touch after compensating for the ungrounded user effect (e.g., a medium touch signal). As previously described, the Z density and its associated thresholds are provided by way of example only, and it should be understood that other quality factors that can reflect how well or poorly a user is grounded when interacting with the touch screen can be similarly used.

[0186] When an ungrounded user (ungrounded touch) is detected on the touch screen, the touch screen can transition from the full bootstrap operation mode 1441 to the partial bootstrap operation mode 1442 via 1445. In some examples, the ungrounded user can be represented by a Z density of the touch image detected before ungrounded user compensation being less than a first threshold and a Z density of the touch image detected after ungrounded user compensation being greater than a second threshold. When an ungrounded touch is detected on the touch screen, the touch screen can remain in the partial bootstrap operation mode 1442 via 1446.

[0187] The touch screen can transition from the partial bootstrap operation mode 1442 back to the full bootstrap operation mode 1441 in response to the following two conditions: no touch is detected on the touch screen for some threshold amount or time, or a well-grounded user interaction is detected on the touch screen. In some examples, the no touch condition can be represented by a Z density of the touch image detected after ungrounded user compensation (if any) less than a second threshold or a Z density of the touch image detected after ungrounded user compensation greater than a second threshold, but the full bootstrap scanning step in the partial bootstrap operation mode (e.g., Fig. 14B In some examples, a well-grounded user may be indicated by a Z density greater than a first threshold for the touch image detected before ungrounded user compensation and a Z density greater than a second threshold for the touch image detected after ungrounded user compensation.

[0188] Fig.14D Shown with Fig.14A 1408. At 1452, a first mutual capacitance scan of the touch screen (e.g., MC1 1408) may be performed. At 1454, it may be determined whether process 1450 is at the beginning of a touch frame (e.g., touch frame 1404). In some examples, this may be determined by checking whether one or two mutual capacitance scans (e.g., MC1 1408, MC2 1414) have occurred on the touch screen, and if so, the answer to 1454 may be "yes", and if so, the answer to 1454 may be "no". If process 1450 is at the beginning of a touch frame, a first full bootstrap scan of the touch screen (e.g., FB1 1432) may be performed at 1456. At 1458, a second full bootstrap scan of the touch screen (e.g., FB2 1434) may be performed. At 1460, a second mutual capacitance scan of the touch screen (e.g., MC2 1414) may be performed.

[0189] If at 1454, process 1450 is not at the beginning of a touch frame, a third full bootstrap scan of the touch screen (e.g., FB3 1436) may be performed at 1462. At 1464, a fourth full bootstrap scan of the touch screen (e.g., FB4 1438) may be performed.

[0190] At 1466, a noise floor can be subtracted from the total full bootstrap touch images acquired from the first full bootstrap scan, the second full bootstrap scan, the third full bootstrap scan, and the fourth full bootstrap scan of the touch screen. Step 1466 can include subtracting any baseline touch measurements (e.g., a baseline partial bootstrap touch image, a baseline mutual capacitance touch image, etc., a baseline full bootstrap touch image, etc.) that may be stored from a previous scan.

[0191] At 1468, the Z density of any touch that may have been detected in the fully bootstrapped touch image may be determined. If the Z density of the touch before ungrounded user compensation is greater than a first threshold, it may be determined that the user interacting with the touch screen is well grounded. The detected touch activity may be used by the system to perform touch-related functions.

[0192] If the Z density of the touch before ungrounded user compensation is not greater than a first threshold at 1468, the presence of water on the touch screen may be checked at 1470. Specifically, if the mutual capacitance scan of the touch screen includes portions of the touch image that are not included in the full bootstrap scan of the touch screen, these portions of the touch image may be attributed to the presence of water on the touch screen. The portions of the mutual capacitance touch image attributed to water may be removed from the original mutual capacitance touch image to provide a water-repelling mutual capacitance touch image. The water-repelling mutual capacitance touch image may be used to perform ungrounded user compensation on the original full bootstrap touch image to provide a compensated full bootstrap touch image.

[0193] At 1472, it can be determined whether the Z density of the touch after the ungrounded user compensation is greater than a second threshold. If so, it can be determined that the user interacting with the touch screen is poorly grounded, and the touch screen can be transitioned to a partial bootstrap operation mode in the next touch frame via 1480 (in Fig.14E ).

[0194] If the Z density of the touch after ungrounded user compensation is not greater than the second threshold, it may be determined whether the mutual capacitance touch image contains any touch image at 1474. If not, it may be determined at 1476 that there is no touch and no water on the touch screen, and the mutual capacitance touch image and the fully bootstrapped touch image measured above may be captured / stored to be used as a baseline measurement in subsequent scans.

[0195] If the mutual capacitance touch image contains a touch image, it can be determined that there is no actual touch on the touch screen, but there is water on the touch screen at 1478. The mutual capacitance touch images measured above can be captured / stored for use as baseline measurements, which can be used to eliminate the effect of water in subsequent scans.

[0196] Fig.14E Shown with Fig. 14B 14. Example process 1451 corresponding to the water detection and water rejection steps of the touch screen. At 1453, process 1451 can start with a full bootstrap scan of the touch screen (e.g., FB 1420). At 1455, a first mutual capacitance scan of the touch screen (e.g., MC1 1408) can be performed. At 1457, it can be determined whether process 1451 is at the beginning of a touch frame (e.g., touch frame 1404). In some examples, this can be determined by checking whether the touch screen has undergone one or two full bootstrap scans (e.g., FB 1420), if one, the answer to 1457 can be "yes", and if two, the answer to 1457 can be "no". If process 1451 is at the beginning of a touch frame, a first partial bootstrap scan of the touch screen (e.g., PB1 1410) can be performed at 1459. At 1461, a second partial bootstrap scan of the touch screen (e.g., PB2 1412) can be performed. At 1463, another full bootstrap scan of the touch screen can be performed (eg, FB 1420). At 1465, a second mutual capacitance scan of the touch screen can be performed (eg, MC2 1414).

[0197] If process 1451 is not at the start of a touch frame at 1457, a third partial bootstrap scan of the touch screen (e.g., PB3 1416) may be performed at 1467. At 1469, a fourth partial bootstrap scan of the touch screen (e.g., PB4 1418) may be performed.

[0198] At 1471, a noise floor can be subtracted from the total partial bootstrap touch images acquired from the first partial bootstrap scan, the second partial bootstrap scan, the third partial bootstrap scan, and the fourth partial bootstrap scan of the touch screen. Step 1471 can include subtracting any baseline touch measurements (e.g., a baseline partial bootstrap touch image, a baseline mutual capacitance touch image, etc., a baseline full bootstrap touch image, etc.) that may be stored from a previous scan.

[0199] At 1473, the touch screen may be checked for the presence of water. Specifically, if the partial bootstrap scan of the touch screen includes portions of the touch image that are not included in the full bootstrap scan of the touch screen, those portions of the touch image may be attributed to water present on the touch screen. The portions of the partial bootstrap touch image attributed to water may be removed from the original partial bootstrap touch image to provide a water-repelling partial bootstrap touch image, and the portions of the partial bootstrap touch image attributed to water may also be removed from the original mutual capacitance touch image to provide a water-repelling mutual capacitance touch image. Ungrounded user compensation may be performed on the original partial bootstrap touch image using the water-repelling partial bootstrap touch image and the water-repelling mutual capacitance touch image to provide a compensated partial bootstrap touch image.

[0200] At 1475, the compensated partial bootstrap touch image can be analyzed to determine whether there is touch activity in the touch image (whether due to water or due to actual touch). If there is no touch activity, then at 1477 it can be determined that there is no touch and no water on the touch screen, and the partial bootstrap touch image and mutual capacitance touch image measured above can be captured / stored to be used as baseline measurements in subsequent scans. In addition, the touch screen can return to the full bootstrap operation mode in the next touch frame via 1479.

[0201] If there is touch activity in the compensated partial bootstrap touch image at 1475, it can be determined at 1481 whether the full bootstrap touch image contains touch activity. If there is no touch activity, it can be determined at 1483 that there is no actual touch on the touch screen, but there is water on the touch screen. The partial bootstrap touch image and mutual capacitance touch image measured above can be captured / stored for use as baseline measurements, which can be used as a benchmark to measure the effect of water in subsequent scans. In addition, the touch screen can return to the full bootstrap operation mode in the next touch frame via 1479.

[0202] If touch activity is present in the full bootstrap touch image at 1481, then it may be determined that actual touch activity and water are present on the touch screen at 1485. Touch activity due to water may be excluded from the compensated partial bootstrap touch image by comparing the partial bootstrap touch image with the full bootstrap touch image, as described in the present disclosure, and may result in water-repelling touch activity, which the system may utilize to perform touch-related functions.

[0203] At 1487, it may be determined whether the Z density of the identified touch activity is greater than a first threshold. If the Z density is greater than the first threshold, it may be determined that the user interacting with the touch screen is well grounded, and the touch screen may be returned to the full bootstrap mode of operation via 1479. If the Z density is not greater than the first threshold, it may be determined that the user interacting with the touch screen is poorly grounded, and the touch screen may remain in the bootstrap mode of operation. Fig.14EThe partial bootstrap operation mode is shown in .

[0204] Ungrounded user compensation

[0205] Sometimes, the touch screen can be a partially bootstrapped touch screen, where some touch nodes can be driven and sensed, some touch nodes can be driven but not sensed, and some touch nodes can be grounded, as described above. However, in some examples, a user or object interacting with the touch screen may not be fully grounded, which can cause attenuation of the self-capacitive touch signal detected on the touch screen. Ungrounded user compensation can utilize various techniques to reduce the effects of such ungrounded interactions with the touch screen, including with a partially bootstrapped touch screen. An exemplary scheme for performing ungrounded user compensation as discussed above in the present disclosure will now be described.

[0206] Fig.15A An exemplary driving and sensing scheme is shown in which each touch node electrode on a touch screen may be driven and sensed at a certain point in time according to examples of the present disclosure. Fig.15A The exemplary drive and sensing scheme of illustrates the scheme as applied to four touch node electrodes, but it should be understood that the scheme can be similarly extended to additional touch node electrodes that may be present on the touch screen of the present disclosure. For example, each group of four touch node electrodes on the touch screen can be driven, sensed, and grounded as described below. In some examples, the group of four touch node electrodes can be driven, sensed, and grounded sequentially, i.e., one at a time. In some examples, the group of four touch node electrodes can be driven, sensed, and grounded at least partially simultaneously, i.e., more than one at a time. The sensing circuit 714, excitation buffer 716, and / or AC grounding buffer 718 (as shown in reference) that can be used Fig. 7A The appropriate number of ) may depend on the number of touch node electrodes on the touch screen, and whether the touch screen will operate in a single excitation mode or a multi-excitation mode.

[0207] A first self-capacitance scan may be performed during a first self-capacitance scan period, and the touch electrodes may be driven and sensed as shown in configuration 1502. Specifically, the upper left touch node electrode (DS touch node electrode) may be driven and sensed, the upper right and lower left touch node electrodes (D touch node electrodes) may be driven but not sensed, and the lower right touch node electrode may be grounded (G touch node electrode). The mechanism for driving, sensing, and / or grounding these touch node electrodes may be as described above, and for the sake of brevity, the details thereof are not repeated herein.

[0208] After the first self-capacitance scan time period, a second self-capacitance scan may be performed in a second self-capacitance scan time period. In the second self-capacitance scan time period, the touch node electrodes may be driven and sensed as shown in configuration 1504. Specifically, the upper right touch node electrode may be driven and sensed, the upper left and lower right touch node electrodes may be driven but not sensed, and the lower left touch node electrode may be grounded. In other words, the drive, sense, and grounding scheme of configuration 1502 may be rotated in a clockwise direction to reach configuration 1504. The drive, sense, and grounding scheme of configuration 1504 may similarly be rotated in a clockwise direction to reach configuration 1506 in a third self-capacitance scan time period, and rotated in a clockwise direction again to reach configuration 1508 in a fourth self-capacitance scan time period. After four self-capacitance scan time periods have passed, all touch node electrodes on the touch screen may have been driven and sensed, so a complete touch image may be captured, while continuing to achieve the beneficial effects of the aforementioned partial bootstrap drive and sensing scheme. It should be understood that other drive and sense configurations may be utilized to scan each touch node electrode on the touch screen, and that the configuration provided is merely one example. For example, the drive and sense configurations may be rotated in a counterclockwise direction rather than a clockwise direction to achieve substantially the same results. Additionally, in some examples, the DS and G touch screen electrodes need not be arranged diagonally, but may be treated as adjacent touch node electrodes; the techniques described in this disclosure may be appropriately adjusted to operate properly in these examples. Similarly, other spatial arrangements of DS, D, and / or G touch node electrodes on a touch screen are contemplated.

[0209] Fig.15A Each of the four drive and sense configurations shown can be associated with its own attenuation factor. Figure 5B As discussed above, the attenuation factor of configuration 1502 can be expressed as:

[0210] α1=(C g +∑C4) / C 总 (12)

[0211] Among them C g may represent the capacitance between a finger (or other object) and the system ground, ΣC4 may represent the total self-capacitance associated with the touch node electrode at position 4 (ie, bottom right) across the entire touch screen, and C 总 Can be C g +∑C1+∑C2+∑C3+∑C4.∑C1, ∑C2, and ∑C3 may be the total self capacitances associated with the touch node electrodes at position 1 (upper left), position 2 (upper right), and position 3 (lower left) across the entire touch screen, respectively.

[0212] The attenuation factors for configurations 1504, 1506, and 1508, respectively, may be similarly expressed as:

[0213] α2=(C g +∑C3) / C 总 (13)

[0214] α3=(C g +∑C2) / C 总 (14)

[0215] α4=(C g +∑C1) / C 总 (15)

[0216] Although the attenuation factor of the partially bootstrapped touch screen of the present disclosure may be greater than that of the Figure 5A Although the attenuation factor of the fully bootstrapped touch screen is reduced, it is still beneficial to correct for the partial bootstrapped attenuation to recover a larger amplitude touch signal from the partially bootstrapped touch screen. Having a larger amplitude touch signal can make it easier to identify touch activity and associated touch processing.

[0217] One method of canceling or correcting for attenuation in a partially bootstrapped touch screen may be to scale the self-capacitance values ​​measured on the touch screen by a scaling factor, which may be the inverse of the attenuation factor described above. In this way, the attenuation may be effectively eliminated completely, and the unattenuated self-capacitance value of each touch node electrode may be substantially restored, or the self-capacitance value associated with a well-grounded finger (or object) may be substantially determined. Fig.15A An exemplary scaling factor for the measured self-capacitance values ​​for each of the drive and sense configurations shown may be expressed as:

[0218] K1=1 / α1=C 总 / (C g +∑C4) (16)

[0219] K2=1 / α2=C 总 / (C g +∑C3) (17)

[0220] K3=1 / α3=C 总 / (C g +∑C2) (18)

[0221] K4=1 / α4=C 总 / (C g +∑C1) (19)

[0222] One difficulty in applying the above scaling may be that C g, ∑C1, ∑C2, ∑C3, and ∑C4 may be unknown quantities, since ∑C1, ∑C2, ∑C3, and ∑C4 may represent the unattenuated total self-capacitance of the touch node electrodes at these corresponding locations, rather than the measured (i.e., attenuated) self-capacitance of these touch node electrodes. g That is, the capacitance between the finger (or other object) and the system ground is also unknown. Therefore, in addition to the self-capacitance measurement described above, further measurements may need to be performed to determine the above scaling factor.

[0223] One method of determining the above scaling factors may be to use the touch node electrodes of the present disclosure to perform one or more mutual capacitance measurements in addition to self capacitance measurements. Fig. 15B An exemplary mutual capacitance driving and sensing scheme that can be used with the touch screen of the present disclosure is shown. The mutual capacitance driving and sensing scheme can be used before, after, or during the self-capacitance driving and sensing scheme described above. In addition, Fig. 15B An exemplary mutual capacitance drive and sensing scheme of FIG. 1 is illustrated as applied to four touch node electrodes, but it should be understood that the scheme can be similarly extended to additional touch node electrodes that may be present on the touch screen of the present disclosure. For example, each group of four touch node electrodes on the touch screen can be driven, sensed, and grounded as described below. In some examples, the group of four touch node electrodes can be driven, sensed, and grounded sequentially, i.e., one at a time. In some examples, the group of four touch node electrodes can be driven, sensed, and grounded at least partially simultaneously, i.e., more than one at a time.

[0224] The first mutual capacitance scan may be performed during a first mutual capacitance scan time period. During the first mutual capacitance scan time period, the touch node electrodes of the touch screen may be driven and sensed, as shown in configuration 1510. Specifically, the upper left touch node electrode (D touch node electrode) may be driven, the lower right touch node electrode (S touch node electrode) may be sensed, and the upper right and lower left touch node electrodes (G touch node electrodes) may be grounded. This configuration 1510 may allow for measuring the mutual capacitance between the D and S touch node electrodes. The first mutual capacitance measurement obtained during the first mutual capacitance scan time period may be a common mode measurement (i.e., all sensed mutual capacitance signals between the D and S touch node electrodes on the touch screen may be added together). In some examples, the common mode measurement may be obtained by exciting multiple D touch node electrodes using an excitation buffer, grounding multiple G touch node electrodes using an AC grounding buffer, and / or sensing multiple S touch node electrodes using a readout amplifier (e.g., a sensing circuit). In some examples, the touch node electrodes may be driven, sensed, and / or grounded by individual excitation buffers, sense amplifiers, and / or AC ground buffers, and the resulting sense outputs may be summed together to obtain a common-mode mutual capacitance measurement. The mechanism for driving, sensing, and / or grounding the touch node electrodes may be similar to the schemes described previously (e.g., with respect to Fig. 7A For the sake of brevity, the details of the above embodiments will not be repeated herein.

[0225] After the first mutual capacitance scan time period, a second mutual capacitance scan may be performed in a second mutual capacitance scan time period. In the second mutual capacitance scan time period, the touch node electrodes may be driven and sensed as shown in configuration 1512. Specifically, the upper right touch node electrode may be driven, the lower left touch node electrode may be sensed, and the upper left and lower right touch node electrodes may be grounded. The second mutual capacitance measurement obtained in the second mutual capacitance scan time period may also be a common mode measurement (i.e., all sensed mutual capacitance signals between the D and S touch node electrodes on the touch screen may be added together). After two mutual capacitance scan time periods, mutual capacitance measurements between each pair of diagonal touch node electrodes on the touch screen may be obtained. It should be understood that other drive and sense configurations may be used to obtain mutual capacitance measurements of examples of the present disclosure, and the configuration provided is merely an example. For example, in configuration 1510, instead of driving the upper left touch node electrode and sensing the lower right touch node electrode, the lower right touch node electrode may be driven and the upper left touch node electrode may be sensed to obtain substantially the same result. It should be understood that the "mutual capacitance" used in this disclosure may refer to the nominal capacitance shown between multiple components on a touch screen (e.g., between D and S touch node electrodes), or, where appropriate, to the nominal capacitance change shown between multiple components of the touch screen.

[0226] Fig. 15C Various capacitances associated with the mutual capacitance drive and sense scheme of the present disclosure are shown. Fig. 15B The mutual capacitance drive and sense scheme shown can be designed to measure mutual capacitance through a finger (or through an object); for example, measuring mutual capacitance from a touch node electrode to a finger or object (represented by node 1518) and then back from the finger or object to another touch node electrode. However, direct mutual capacitance that may exist directly between touch node electrodes may also be included in the measurement.

[0227] Specifically, the total modulus through-finger mutual capacitance measured between the D touch node electrode and the S touch node electrode using configuration 1510 can be expressed as:

[0228] ∑C M14 =(∑C1*∑C4) / C 总 -∑C NM14 (20)

[0229] Where ∑C1 and ∑C4 are the total self-capacitance between the touch node electrodes at position 1 (upper left) and position 4 (lower right) and the finger 1518 on the entire touch screen, respectively. 总 Can be C g +∑C1+∑C2+∑C3+∑C4, as mentioned above. Finally, ∑C NM14 It can be the total direct mutual capacitance between the touch node electrodes at location 1 and location 4 (“approximate mutual capacitance”).

[0230] Similarly, the total measured through-finger mutual capacitance between the D touch node electrode and the S touch node electrode using configuration 1512 may be expressed as:

[0231] ∑C M23 =(∑C2*∑C3) / C 总 -∑C NM23 (twenty one)

[0232] Where ∑C2 and ∑C3 are the total self-capacitance between the touch node electrodes at position 2 (upper right) and position 3 (lower left) and the finger 1518 on the entire touch screen, respectively. NM23 It can be the total direct mutual capacitance between the touch node electrodes at Location 2 and Location 3 (“approximate mutual capacitance”).

[0233] Since ∑C NM14 and ∑C NM23may be undesirable terms, approximate values ​​of these terms that may be based on capacitance field simulation results may be determined and substituted into equations (20) and (21). These approximate values ​​may be based on one or more of the geometry / spacing of the touch node electrodes and the position of the finger (object) relative to the touch node electrodes. Specifically, the approximate relationship between the self-capacitance and mutual capacitance between the diagonal touch node electrodes may be determined using capacitance field simulation and may be expressed as:

[0234] ∑C NM14 =β*(∑C1*∑C4) / (∑C1+∑C4) (22)

[0235] ∑C NM23 =β*(∑C2*∑C3) / (∑C2+∑C3) (23)

[0236] Where β can be approximated as a constant. By substituting equations (22) and (23) into equations (20) and (21), we can obtain ∑C which can be a function of C1, C2, C3, and C4. M14 and ∑C M23 In addition, the above mutual capacitance measurement can be used to obtain ∑C M14 and ∑C M23 The actual measured value.

[0237] In addition to the above ∑C M14 and ∑C M23 In addition to the measurement of , four self-capacitance measurements can be obtained on the touch screen during the aforementioned four self-capacitance scanning time periods. These four measurements can be expressed as:

[0238] ∑XC1=α1*∑C1-∑C NM14 (twenty four)

[0239] ∑XC2=α2*∑C2-∑C NM23 (25)

[0240] ∑XC3=α3*∑C3-∑C NM23 (26)

[0241] ∑XC4=α4*∑C4-∑C NM14 (27)

[0242] Where ∑XC y may represent the total self-capacitance measured at the touch node electrode at position y on the touch screen, α y As can be expressed in equations (17) to (20), ΣC y It can be the total self capacitance of the touch node electrode at position y on the touch screen, ∑C NMxymay represent the total direct mutual capacitance ("approximate mutual capacitance") between the touch node electrodes at position x and position y on the touch screen. This approximate capacitance term may affect the self-capacitance that may be measured at each touch node electrode, since this mutual capacitance may exist between the DS touch node electrode and the G touch node electrode, and its behavior may be opposite to that of the self-capacitance (i.e., the absolute value of the approximate mutual capacitance may increase when the self-capacitance increases, but the sign of the change in mutual capacitance may be opposite to the sign of the change in self-capacitance). Therefore, this approximate mutual capacitance term may be included in equations (24) to (27), as shown herein.

[0243] Equations (20) to (21) and (24) to (27) can be manipulated to obtain equations for ∑C1, ∑C2, ∑C3, and ∑C4, which are the unattenuated total self-capacitance at the touch node electrodes at location 1, location 2, location 3, and location 4, respectively. Specifically, these equations can be determined as:

[0244]

[0245]

[0246]

[0247]

[0248] In equations (28) to (31), only C g and β are unknown quantities, although β can be approximated as appropriate constants based on capacitance field simulation results. The remaining terms can be derived from four self-capacitance measurements and two mutual capacitance measurements (e.g., ∑XC4, ∑C M14 The corresponding one of equations (28) to (31) can be substituted into the scaling factor equations (16) to (19) to obtain expressions for K1, K2, K3, and K4. For example, equation (31) can be substituted into equation (16) to obtain the following expression for K1:

[0249] in:

[0250]

[0251] In equation (32), only β is an unknown quantity, since C in equations (16) and (31) g β can be approximated as an appropriate constant based on the capacitance field simulation results, and the remaining terms can be known measured quantities (e.g., ∑XC4, ∑C M14, etc.). Therefore, K1 can be determined based on the four self-capacitance and two mutual capacitance measurements obtained on the touch screen of the present disclosure. K1 can then be used to scale the self-capacitance measurement obtained from the touch node electrode at position 1 on the touch screen to effectively eliminate the attenuation that may be caused by the partially bootstrapped touch screen. The self-capacitance measurements obtained from the touch node electrodes at positions 2, 3, and 4 on the touch screen can similarly be scaled using appropriate scaling factors represented by the following equations to effectively eliminate their respective attenuations:

[0252]

[0253]

[0254]

[0255] As an alternative to scaling the touch node electrodes at corresponding locations using individual scaling factors, in some examples, an average scaling factor can be used to scale all self-capacitance measurements taken at all touch node electrodes on the touch screen. This average scaling factor can provide sufficient accuracy so that individualized scaling factors may not be required. The average scaling factor for a partially bootstrapped touch screen can be expressed as:

[0256]

[0257] As described above, attenuation of touch signals detectable on the touch screen of the present disclosure can be effectively eliminated by scaling the touch signals using a scaling factor that can be determined using four self-capacitance measurements and two mutual capacitance measurements. These measurements can be captured using any combination of full bootstrap scanning, partial bootstrap scanning, and / or mutual capacitance scanning described above in the context of water rejection.

[0258] The above-described ungrounded user compensation scheme can be applied to a partially bootstrapped touch screen. In some examples, ungrounded user compensation may be required for a fully bootstrapped touch screen (e.g., Fig.14D 1451 in process 1452). Ungrounded user compensation for a fully bootstrapped touch screen can be performed in a manner similar to ungrounded user compensation for a partially bootstrapped touch screen, as described below.

[0259] Specifically, re-refer to Figure 5A , the attenuation factor of a fully bootstrapped touch screen can be expressed by equation (2), and the effective self-capacitance sensed at any one touch node electrode can be expressed by equation (4), which are reproduced below:

[0260] α=C g / C 总 (2)

[0261] C 有效，X =α*C X (4)

[0262] Among them C 总 =C g +C1+C2+C3+C4 (Equation (3)), and C X It can be C1 503, C2 505, C3 507 or C4 509. Therefore, in order to substantially eliminate the above attenuation, a scaling factor of 1 / α or C 总 / C g To scale the self-capacitance value of the touch node.

[0263] As previously described, mutual capacitance measurements can be used to determine the appropriate fully bootstrapped scaling factor described above. Specifically, FIG. 15B to FIG. 15C A mutual capacitance scan of can be used to obtain mutual capacitance measurements of a passing finger, which can be expressed as:

[0264] ∑C M =(∑C FD *∑C FS ) / C 总 (38)

[0265] Where ∑C FD It can be the sum of all driven touch node electrode to finger capacitance (for example, Fig. 15C ∑C1 in the configuration 1510, and ∑C FS It can be the sum of all the sensing touch node electrode to finger capacitance (for example, Fig. 15C ∑C4 in configuration 1512 in ). Equation (38) can be combined with the effective self-capacitance measurement obtained during a full bootstrap touch screen scan (e.g., equation (4)) to provide an equation for the full bootstrap scaling factor:

[0266] K FB =C 总 / C g =∑C M / ∑C 有效，FS +∑C M / ∑C 有效，FD +1 (39)

[0267] Since the above mutual capacitance measurement may include direct mutual capacitance effects between diagonal touch node electrodes (as mentioned above), the above fully bootstrapped scaling factor may include some non-ideal factors, which can be expressed as:

[0268] K FB，理想 =K FB，非理想 / (1-β) (40)

[0269] Where β can be expressed as:

[0270] β=∑C NM / ((∑C FS *∑C FD ) / (∑C FS +∑C FD )) (41)

[0271] Where ∑C NM It can be between touch node electrodes on the touch screen (for example, Fig. 15C The total direct mutual capacitance ("approximate mutual capacitance") between touch node electrodes 1 and 4 in configuration 1510 in FIG. 15A and FIG. 15B) can be determined using field software simulations to show that the dependence of β on the exact touch location may be small and therefore need not be considered above, or can be determined using field software simulations.

[0272] Based on equation (38), Fig. 15C The through-finger mutual capacitance of the two mutual capacitance configurations shown can be expressed as:

[0273] C M14 =(C1*C4) / C 总 (42)

[0274] C M23 =(C2*C3) / C 总 (43)

[0275] In addition, based on equations (2) and (4), Figure 5A The effective self capacitance (XC) measured at each touch node in y ) can be expressed as:

[0276] XC1=C g / C 总 *C1 (44)

[0277] XC2=C g / C 总 *C2 (45)

[0278] XC3=C g / C 总 *C3 (46)

[0279] XC4=C g / C 总 *C4 (47)

[0280] Combining the fully bootstrapped valid measurement described above with the mutual capacitance measurement (e.g. Figure 5A Scan and Fig. 15C The scan of equations (42) to (47) shows that the ideal fully bootstrapped scaling factor can be expressed as:

[0281] KFB，理想 =∑C M14 / ∑XC4+∑C M14 / ∑XC1+∑C M23 / ∑XC3+

[0282] ∑C M23 / ∑XC2+1 (48)

[0283] Where ∑XC y may represent the total measured self-capacitance between a touch node electrode and a finger on the touch screen during a full bootstrap scan, and ∑C Myz It can represent the total measurement on the touch screen through the finger mutual capacitance.

[0284] The non-ideal factors can be accounted for by β, as discussed above in equation (40). Specifically, for Fig. 15C For the configuration shown, equation (41) for β can be expressed as follows:

[0285] β=∑C NM14 / ((∑C4*∑C1) / (∑C4+∑C1))+

[0286] ∑C NM23 / ((∑C3*∑C2) / (∑C3+∑C2)) (49)

[0287] Therefore, using the above relationship, ungrounded user compensation can be performed for a fully bootstrapped touch screen.

[0288] Thus, examples of the present disclosure provide one or more configurations for detecting water and water rejection on a touch screen, and doing so with or without ungrounded user compensation.

[0289] Therefore, according to the above, some examples of the present disclosure relate to a touch sensor panel, the touch sensor panel including: a plurality of touch node electrodes; and a touch controller, the touch controller being configured to: drive and sense the plurality of touch node electrodes in a fully bootstrapped configuration to obtain a fully bootstrapped touch image; drive and sense the plurality of touch node electrodes in a second configuration different from the fully bootstrapped configuration to obtain a second touch image, the second touch image including the effect of water on the touch sensor panel; and determine a final touch image based on the fully bootstrapped touch image and the second touch image, the final touch image compensating the effect of water on the touch sensor panel. In addition to or as an alternative to one or more of the examples disclosed above, in some examples, the second configuration includes a mutual capacitance configuration. In addition to or as an alternative to one or more of the examples disclosed above, in some examples, the second configuration includes a partially bootstrapped configuration. In addition to or as an alternative to one or more of the examples disclosed above, in some examples, the final touch image includes a touch image of a first portion of the touch sensor panel, the touch sensor panel including a first portion of the touch sensor panel and a second portion of the touch sensor panel. In addition to or alternatively to one or more of the examples disclosed above, in some examples, the first portion of the touch sensor panel includes a plurality of touch node electrodes. In addition to or alternatively to one or more of the examples disclosed above, in some examples, the first portion of the touch sensor panel includes a first portion of a plurality of touch node electrodes, the plurality of touch node electrodes including a first portion of a plurality of touch node electrodes and a second portion of a plurality of touch node electrodes. In addition to or alternatively to one or more of the examples disclosed above, in some examples, the touch controller is configured to drive and sense a plurality of touch node electrodes in a fully bootstrapped configuration during a touch frame and to drive and sense a plurality of touch node electrodes in a second configuration. In addition to or alternatively to one or more of the examples disclosed above, in some examples, the touch controller is configured to drive and sense a plurality of touch node electrodes in a fully bootstrapped configuration with reduced resolution. In addition to or alternatively to one or more of the examples disclosed above, in some examples, the touch controller is configured to drive and sense a plurality of touch node electrodes in a second configuration with reduced resolution. Additionally or alternatively to one or more of the examples disclosed above, in some examples, the touch controller is configured to detect touch activity on the touch sensor panel and determine the second configuration based on the touch activity.

[0290] Some examples of the present disclosure relate to a method, comprising: driving and sensing a plurality of touch node electrodes on a touch sensor panel in a fully bootstrapped configuration to obtain a fully bootstrapped touch image; driving and sensing a plurality of touch node electrodes in a second configuration different from the fully bootstrapped configuration to obtain a second touch image, the second touch image including the effect of water on the touch sensor panel; and determining a final touch image based on the fully bootstrapped touch image and the second touch image, the final touch image compensating for the effect of water on the touch sensor panel. In addition to or alternatively to one or more of the examples disclosed above, in some examples, the second configuration includes a mutual capacitance configuration. In addition to or alternatively to one or more of the examples disclosed above, in some examples, the second configuration includes a partially bootstrapped configuration. In addition to or alternatively to one or more of the examples disclosed above, in some examples, the final touch image includes a touch image of a first portion of the touch sensor panel, the touch sensor panel including a first portion of the touch sensor panel and a second portion of the touch sensor panel. In addition to or alternatively to one or more of the examples disclosed above, in some examples, the first portion of the touch sensor panel includes a plurality of touch node electrodes. In addition to or alternatively to one or more of the examples disclosed above, in some examples, the first portion of the touch sensor panel includes a first portion of a plurality of touch node electrodes, the plurality of touch node electrodes including a first portion of a plurality of touch node electrodes and a second portion of a plurality of touch node electrodes. In addition to or alternatively to one or more of the examples disclosed above, in some examples, driving and sensing the plurality of touch node electrodes in a fully bootstrapped configuration and driving and sensing the plurality of touch node electrodes in a second configuration are performed during a touch frame. In addition to or alternatively to one or more of the examples disclosed above, in some examples, driving and sensing the plurality of touch node electrodes in a fully bootstrapped configuration includes driving and sensing the plurality of touch node electrodes in a fully bootstrapped configuration with reduced resolution. In addition to or alternatively to one or more of the examples disclosed above, in some examples, driving and sensing the plurality of touch node electrodes in a second configuration includes driving and sensing the plurality of touch node electrodes in a second configuration with reduced resolution. In addition to or alternatively to one or more of the examples disclosed above, in some examples, the method further includes: detecting a touch activity on the touch sensor panel; and determining the second configuration based on the touch activity.

[0291] Although the examples of the present disclosure have been fully described with reference to the accompanying drawings, it should be noted that various changes and modifications will become apparent to those skilled in the art. It should be understood that such changes and modifications are considered to be included within the scope of the examples of the present disclosure defined by the appended claims.

Claims

1. A touch sensor panel, comprising: A plurality of touch node electrodes; as well as A touch controller, wherein the touch controller is configured to: In the first touch frame: The plurality of touch node electrodes are driven and sensed in a fully bootstrapped configuration to obtain a fully bootstrapped touch image, wherein in the fully bootstrapped configuration: Driving and sensing the plurality of touch node electrodes includes simultaneously and independently driving and sensing each of the plurality of touch node electrodes; In a second touch frame following the first touch frame: performing a first set of scanning steps based on determining that one or more criteria are satisfied, the one or more criteria including a criterion that the presence of water is detected at the plurality of touch node electrodes, wherein the first set of scanning steps includes one or more scanning steps of a first type and one or more scanning steps of a second type different from the first type; and Based on determining that the one or more criteria are not met, performing a second set of scanning steps different from the first set of scanning steps, wherein the second touch frame includes one or more scanning steps of the first type but does not include one or more scanning steps of the second type. 2 . The touch sensor panel of claim 1 , wherein driving and sensing the plurality of touch node electrodes in a fully bootstrapped configuration comprises driving and sensing each of the plurality of touch node electrodes simultaneously.

3. The touch sensor panel of claim 1 , wherein the touch controller is further configured to: In a first touch frame, driving and sensing mutual capacitances of the plurality of touch node electrodes to acquire a mutual capacitance touch image; and The presence of water is determined based on the fully bootstrapped touch image and the mutual capacitance touch image. 4 . The touch sensor panel of claim 1 , wherein the one or more criteria include a criterion that touch activity is detected at the plurality of touch node electrodes.

5. The touch sensor panel of claim 4, wherein the touch controller is further configured to: Touch activity at the plurality of touch node electrodes is detected based at least on the fully bootstrapped touch image.

6. A touch sensor panel according to claim 1, wherein the first type of scanning step is scanning when in either a fully bootstrap configuration or a partially bootstrap configuration, and the second type of scanning step is scanning when in the other of the fully bootstrap configuration or the partially bootstrap configuration.

7. The touch sensor panel of claim 6, wherein the touch controller is further configured to: A final touch image is determined based on the corresponding fully bootstrapped touch image and the corresponding partially bootstrapped touch image, the final touch image compensating for effects of water on the touch sensor panel.

8. The touch sensor panel of claim 1, wherein: Based on determining that the one or more criteria are not met and based on determining that touch activity is not detected at the plurality of touch node electrodes, the second set of scanning steps includes scanning while in the fully bootstrap configuration, but does not include other scanning while in the fully bootstrap configuration or the partially bootstrap configuration.

9. The touch sensor panel of claim 1 , wherein the touch controller is further configured to: Based on determining that no touch activity is detected at the plurality of touch node electrodes, baseline touch data for the plurality of touch node electrodes is updated.

10. A method comprising: In the first touch frame: A plurality of touch node electrodes are driven and sensed in a fully bootstrapped configuration to obtain a fully bootstrapped touch image, wherein: Driving and sensing the plurality of touch node electrodes includes simultaneously and independently driving and sensing each of the plurality of touch node electrodes; In a second touch frame following the first touch frame: performing a first set of scanning steps based on determining that one or more criteria are satisfied, the one or more criteria including a criterion that the presence of water is detected at the plurality of touch node electrodes, wherein the first set of scanning steps includes one or more scanning steps of a first type and one or more scanning steps of a second type different from the first type; and Based on determining that the one or more criteria are not met, performing a second set of scanning steps different from the first set of scanning steps, wherein the second touch frame includes one or more scanning steps of the first type but does not include one or more scanning steps of the second type. 11 . The method of claim 10 , wherein driving and sensing the plurality of touch node electrodes in a fully bootstrapped configuration comprises driving and sensing each of the plurality of touch node electrodes simultaneously.

12. The method according to claim 10, further comprising: In a first touch frame, driving and sensing the mutual capacitance of the plurality of touch node electrodes to acquire a mutual capacitance touch image; as well as The presence of water is determined based on the fully bootstrapped touch image and the mutual capacitance touch image.

13. The method of claim 10, wherein the one or more criteria include a criterion that touch activity is detected at the plurality of touch node electrodes.

14. The method according to claim 13, further comprising: Touch activity at the plurality of touch node electrodes is detected based at least on the fully bootstrapped touch image.

15. The method according to claim 10, wherein: The first type of scanning step is scanning in either a fully bootstrapped configuration or a partially bootstrapped configuration, and the second type of scanning step is scanning in the other of the fully bootstrapped configuration or the partially bootstrapped configuration.

16. The method according to claim 15, further comprising: A final touch image is determined based on the corresponding fully bootstrapped touch image and the corresponding partially bootstrapped touch image, the final touch image compensating for the effect of water on the touch sensor panel.

17. The method of claim 10, wherein: Based on determining that the one or more criteria are not met and based on determining that touch activity is not detected at the plurality of touch node electrodes, the second set of scanning steps includes scanning while in the fully bootstrap configuration, but does not include other scanning while in the fully bootstrap configuration or the partially bootstrap configuration.

18. The method according to claim 10, further comprising: Based on determining that no touch activity is detected at the plurality of touch node electrodes, baseline touch data for the plurality of touch node electrodes is updated.

Images