Touch sensor controller and method of operation of a touch sensor controller

Abstract

Touch sensor controllers, methods of operating the same, and touch screen driving circuits are provided. The touch sensor controller is for driving a touch sensor stacked on a display panel and including drive electrodes and receive electrodes crossing the drive electrodes, the touch sensor controller including a drive circuit configured to sequentially provide drive signals to the drive electrodes, a readout circuit configured to, in response to the drive signals, generate touch data based on first sense signals received from the receive electrodes and generate display noise data based on second sense signals received from first drive electrodes among the drive electrodes to which no drive signal is applied, and a touch processor configured to determine whether a touch input has occurred on the touch sensor based on the touch data and the display noise data.

Description

[0001] Cross-references to related applications

[0002] This application is based on and claims priority to Korean Patent Application No. 10-2021-0016284, filed with the Korean Intellectual Property Office on February 4, 2021, the disclosure of which is incorporated herein by reference in its entirety. Technical Field

[0003] The embodiments relate to a touch sensor controller, a method for operating the touch sensor controller, and a touch screen driver circuit. Background Technology

[0004] A touchscreen may include a display panel for displaying images and a touch sensor for sensing touch, wherein the display panel and the touch sensor may be stacked vertically or may be integrally formed to share at least one layer. Summary of the Invention

[0005] The embodiment relates to a touch sensor controller for driving a touch sensor stacked on a display panel and including driving electrodes and receiving electrodes intersecting the driving electrodes. The touch sensor controller includes: a driving circuit configured to sequentially provide driving signals to the driving electrodes; a readout circuit configured to, in response to the driving signals, generate touch data based on a first sensing signal received from the receiving electrodes and generate display noise data based on a second sensing signal received from a first driving electrode that has not been subjected to a driving signal; and a touch processor configured to determine whether a touch input has occurred on the touch sensor based on the touch data and the display noise data.

[0006] The embodiments also relate to an operation method of a touch sensor controller for driving a touch sensor stacked on a display panel and including driving electrodes and receiving electrodes intersecting the driving electrodes. The operation method includes: applying a driving signal to at least one of the driving electrodes; performing touch sensing by a first receiver disposed in the touch sensor controller; and performing display noise sensing simultaneously by at least one second receiver disposed in the touch sensor controller as the touch sensing is performed.

[0007] The embodiments also relate to a method of operating a touch sensor controller for driving touch sensors stacked on a display panel, the method comprising: the touch sensor controller generating display noise data by performing display noise sensing during a first time period of a display period in which an image is displayed on the display panel; the touch sensor controller generating touch data by performing touch sensing during a second time period of the display period, the second time period being different from the first time period; and the touch sensor controller processing the touch data based on the display noise data.

[0008] The embodiments also relate to a touchscreen driving circuit for driving a touchscreen panel, the touchscreen panel including a display panel and touch sensors stacked on the display panel, the touchscreen driving circuit including: a display driving circuit configured to calculate the amount of change in power supply voltage at various locations on the display panel based on received image data, and to generate compensation information based on the amount of change in power supply voltage; and a touch sensor controller configured to receive the compensation information from the display driving circuit, and to compensate touch data generated based on touch sensing values ​​received from the touch sensor based on the compensation information. Attached Figure Description

[0009] The features will become more readily understood by those skilled in the art by referring to the detailed description of exemplary embodiments in the accompanying drawings, in which:

[0010] Figure 1 This is a block diagram illustrating a touchscreen device according to an example embodiment;

[0011] Figure 2 This is a schematic diagram of a touch sensor controller according to an example embodiment;

[0012] Figure 3 It is a graph used to describe the components of display noise introduced into the touch sensors stacked on the display panel;

[0013] Figure 4 This is a diagram illustrating a display noise sensing method according to an example embodiment;

[0014] Figure 5A and Figure 5B This is a timing diagram illustrating an operation method of a touch sensor controller according to an example embodiment;

[0015] Figure 6 This is a diagram illustrating a display noise sensing method according to an example embodiment;

[0016] Figure 7 It shows Figure 6A diagram of the positive and negative drive signals;

[0017] Figure 8 This is a flowchart of an operation method of a touch sensor controller according to an example embodiment;

[0018] Figure 9 This is a schematic block diagram of a touch sensor controller according to an example embodiment;

[0019] Figure 10 This is a schematic diagram illustrating the operation of the readout circuit according to an example embodiment and a diagram of the readout circuit;

[0020] Figure 11 This is a schematic diagram illustrating the operation of the readout circuit according to an example embodiment and a diagram of the readout circuit;

[0021] Figure 12 This is a flowchart of an operation method of a touch sensor controller according to an example embodiment;

[0022] Figure 13 This is a schematic block diagram of a touchscreen driving circuit according to an example embodiment;

[0023] Figure 14 It shows the setting Figure 13 A flowchart illustrating the operation of the touch sensor controller and display driver circuit in the touch screen driver circuit;

[0024] Figure 15 This is a flowchart of a method for generating a coupled voltage map according to an example embodiment;

[0025] Figure 16 This is a diagram showing the structure of the power cord for the display panel;

[0026] Figure 17 It is a modeling diagram showing the internal structure of the display panel;

[0027] Figure 18 It is a graph showing a decrease in power supply voltage in one column of the display panel;

[0028] Figure 19 This is a schematic block diagram of a touchscreen driving circuit according to an example embodiment;

[0029] Figure 20 This is a flowchart of an operation method of a touch sensor controller according to an example embodiment; and

[0030] Figure 21 and Figure 22 This is a diagram illustrating an example implementation of a touchscreen driver circuit according to an exemplary embodiment. Detailed Implementation

[0031] Figure 1 This is a block diagram illustrating a touchscreen device according to an example embodiment.

[0032] Reference Figure 1 The touchscreen device 1000 can be installed on various electronic devices. For example, the touchscreen device 1000 can be installed on electronic devices such as tablet PCs, e-readers, personal digital assistants (PDAs), portable multimedia players (PMPs), mobile terminals, smartphones, wearable devices, Internet of Things (IoT) devices, refrigerators, navigation devices, etc. Additionally, the touchscreen device 1000 can be installed on electronic devices provided as components of vehicles, furniture, manufacturing facilities, doors, and various measuring devices.

[0033] Reference Figure 1 The touchscreen device 1000 may include a touchscreen 100 and a touchscreen driver circuit 200 for driving the touchscreen 100. The touchscreen 100 may include a touch sensor 110 and a display panel 120 to provide touch sensing and display functions, respectively. The touchscreen driver circuit 200 may include a touch sensor controller (TSC) 210 and a display driver circuit (DDI) 220. The TSC 210 and DDI 220 may be integrated on a single semiconductor chip or may be implemented separately on multiple semiconductor chips. In another implementation, the TSC 210 and DDI 220 may be implemented as a single semiconductor module.

[0034] Although Figure 1 The touchscreen device 1000 is shown to include a host 300, but the host 300 may be implemented separately from the touchscreen device 1000.

[0035] Touchscreen 100 can display images and receive touch input from a user. Touchscreen 100 can function as an input / output device for an electronic device and as a proximity sensor for sensing the proximity of a conductive object. In an example embodiment, touchscreen 100 may also include a fingerprint sensor, and touchscreen device 1000 can perform fingerprint recognition functionality.

[0036] Touch sensor 110 can sense touch (or touch input) on touchscreen 100 and can output a sensing signal. Here, touch includes not only direct contact of a conductive object with touchscreen 100, but also proximity of a conductive object to touchscreen 100. For example, conductive objects can include parts of a user's body (e.g., fingers, palm, face, ears), a stylus pen, etc. Touch sensor 110 can be stacked on display panel 120 and can be attached to the front surface of display panel 120 (e.g., a surface from which light signals are emitted). In an example embodiment, touch sensor 110 can cover the front surface of display panel 120.

[0037] The touch sensor 110 can be implemented as a transparent panel with a touch-sensitive surface. In another implementation, the touch sensor 110 can be implemented as a touch sensor array in which transparent electrodes are patterned.

[0038] The touch sensor 110 may include multiple electrodes. Sensing signals can be output via the electrodes according to one of various touch sensing methods.

[0039] In one example, the electrodes can output sensing signals according to a capacitance sensing method. For example, touch sensor 110 may include a driving electrode to which a driving signal Stx is applied and a receiving electrode to which a sensing signal Ssen is output. The driving electrode may extend in a first direction, while the receiving electrode may extend in a second direction perpendicular to the first direction. The driving electrode and the receiving electrode may be referred to as a driving channel and a receiving channel, respectively. Touch sensor 110 may include a plurality of driving electrodes and a plurality of receiving electrodes arranged side by side. The driving electrodes and receiving electrodes may intersect each other, and mutual capacitance may be formed between the intersecting driving electrodes and receiving electrodes. Each point where mutual capacitance is formed may be referred to as a sensing node of touch sensor 110.

[0040] In another example, touch sensor 110 may include a plurality of sensing electrodes arranged in rows and columns, and a capacitance may be formed in each of the sensing electrodes. For example, a capacitance may be formed between each sensing electrode and ground (or a conductive layer in touchscreen 100), and this capacitance may be referred to as self-capacitance. A drive signal Stx may be applied to each of the sensing electrodes, and a sensing signal Ssen may be output from each of the sensing electrodes. Therefore, each of the sensing electrodes may function as a drive electrode or a receiving electrode, and each of the sensing electrodes may be referred to as a sensing node of touch sensor 110. The drive signal Stx may be applied through the drive electrode, and a sensing signal Ssen representing capacitance (e.g., mutual capacitance or self-capacitance) may be generated based on the drive signal Stx, and a sensing signal Ssen may be output through the receiving electrode. When a conductive object, such as a human finger or stylus, touches or is positioned near a sensing node of touch sensor 110, the capacitance corresponding to the sensing node changes, and the sensing signal Ssen output from touch sensor 110 may change according to the changed capacitance. For example, the level of the sensing signal Ssen can increase or decrease compared to the level before the touch occurred. Touch data can be generated based on the level of the sensing signal Ssen output from the touch sensor 110.

[0041] Display panel 120 may include multiple gate lines, multiple source lines, and multiple pixels arranged in rows and columns at the points where the gate lines and source lines intersect. Pixels can display an image based on image signals Simg received through the source lines and gate lines. The image can be updated according to a set frame rate. Display panel 120 may be implemented as a liquid crystal display (LCD), a light-emitting diode (LED) display, an organic LED (OLED) display, an active-matrix OLED (AMOLED) display, an electrochromic display (ECD), a digital mirror device (DMD), an actuated mirror device (AMD), a grating light valve (GLV), a plasma display panel (PDP), an electroluminescent display (ELD), a vacuum fluorescent display (VFD), and other types of flat or flexible panels.

[0042] although Figure 1 The touch sensor 110 and the display panel 120 are shown to be separate components, but the touch screen 100 can be implemented as an in-cell type panel (where the electrodes of the touch sensor 110 and the pixels of the display panel 120 are combined with each other) or an on-cell type panel (where the electrodes of the touch sensor 110 are arranged on the display panel 120).

[0043] TSC 210 can scan (e.g., drive and sense) touch sensor 110. Therefore, TSC 210 can perform touch sensing. TSC 210 can provide a drive signal Stx to the drive electrode of touch sensor 110 and can receive a sensing signal Ssen generated based on the drive signal Stx from touch sensor 110.

[0044] TSC 210 can convert the sensing signal Ssen, which is an analog signal, into a touch value, which is a digital signal, and can generate touch data that includes touch values ​​corresponding to each sensing node of the touch sensor 110.

[0045] TSC 210 can determine, based on touch data, that a touch input has occurred at at least one specific location on the touchscreen 100, and can calculate the location where the touch input occurred, i.e., the touch coordinates Txy. TSC 210 can send the touch coordinates Txy to the host 300. In an example embodiment, TSC 210 can calculate the touch pressure and can provide that touch pressure, along with the touch coordinates Txy, to the host 300.

[0046] TSC 210 can also determine that a conductive object is near the touchscreen 100 based on touch data. Therefore, TSC 210 can perform proximity sensing. For example, when it is determined based on touch data that a low-level touch input has occurred in a relatively wide area of ​​the touchscreen 100, TSC 210 can determine that a conductive object is near the touchscreen 100. TSC 210 can provide the host 300 with a proximity notification signal N_px indicating that a conductive object is approaching.

[0047] In an example embodiment, TSC 210 may perform noise sensing (e.g., display noise sensing) and touch sensing for touch sensor 110 at the same time or at different times, and may process touch data generated by touch sensing based on noise data generated by noise sensing (e.g., display noise data). For example, TSC 210 may generate compensated touch data by removing noise data from the touch data. For example, TSC 210 may discard touch data when the noise data exceeds a predetermined value. The discarded touch data may be frame data corresponding to a frame of touch sensor 110.

[0048] In an example embodiment, TSC 210 can perform noise sensing at the same time as touch sensing for touch sensor 110, and can remove the noise sensing signal from the touch sensing signal to generate touch data from which noise has been removed.

[0049] In an example embodiment, TSC 210 can receive voltage changes (which contribute to display noise at multiple points on display panel 120) or offset values ​​(which are calculated based on voltage changes) from DDI 220 as compensation information, and can remove the display noise component from the touch data or discard the touch data based on the compensation information.

[0050] As mentioned above, because the TSC 210 removes noise sensing signals from the touch sensing signals or processes touch data based on noise data, it can improve the reliability of touch data and improve touch sensing sensitivity.

[0051] The method for sensing noise segments executed by TSC 210, the method for generating voltage changes executed by DDI 220, and the method for processing touch data based on voltage changes executed by TSC 210 will each be referred to below. Figures 2 to 20 It was described in more detail.

[0052] Still refer to Figure 1 The DDI 220 can receive image data IDT from the host 300 and drive the display panel 120 to display an image on the display panel 120 according to the image data IDT. The DDI 220 can convert the image data IDT into image signals Simg as analog signals and provide these image signals Simg to the corresponding pixels of the display panel 120.

[0053] The host 300 can perform overall control operations on the touchscreen device 1000. The host 300 can generate data related to display operations and provide this data to the DDI 220. The host 300 can receive touch information such as touch coordinates Txy or proximity notification signals N_px from the TSC 210 and can use this touch information to perform control operations. For example, when a proximity notification signal N_px is received while display operations are being performed, the host 300 can stop the display operation by providing a control signal to the DDI 220 to stop the display operation.

[0054] In an example embodiment, host 300 may include an application processor (AP). The AP may be implemented as a system-on-a-chip (SoC). The SoC may include a system bus (not shown) that applies a predetermined standard bus protocol, and may include various intellectual property (IP) connected to the system bus. As a standard protocol for the system bus, various types of protocols may be applied, such as the Advanced Microcontroller Bus Architecture (AMBA) protocol for advanced RISC machines (ARM).

[0055] Figure 2This is a schematic diagram of a TSC according to an example embodiment. For ease of explanation, touch sensor 110 will also be shown.

[0056] Reference Figure 2 The touch sensor 110 may include multiple driving electrodes TE, such as first driving electrodes Y1 to sixth driving electrodes Y6. The touch sensor 110 may include multiple receiving electrodes RE, such as first receiving electrodes X1 to fourth receiving electrodes X4. The number of driving electrodes and receiving electrodes included in the touch sensor 110 may vary depending on the resolution of the touch sensor 110.

[0057] The driving electrode TE can extend in a first direction (e.g., the X-axis direction), while the receiving electrode RE can extend in a second direction orthogonal to the first direction (e.g., the Y-axis direction). The driving electrode TE and the receiving electrode RE can intersect each other. A mutual capacitance C can be formed between the intersecting driving electrode TE and receiving electrode RE. M .

[0058] In an example embodiment, the driving electrode TE and / or the receiving electrode RE may include multiple unit electrodes connected to each other in a first direction or a second direction. Each unit electrode may have a specific shape (e.g., as shown in the image). Figure 2 (The diamond shape shown) or can be in a specific pattern.

[0059] The TSC 210 may include a driver circuit 10, a readout circuit 20, and a touch processor 30 (or control logic).

[0060] The driving circuit 10 may include a plurality of transmitters (TX) 11. The plurality of TX 11 may provide driving signals to driving electrodes TE. Each of the plurality of TX 11 may correspond to at least one driving electrode TE, and the plurality of TX 11 may provide driving signals to its corresponding at least one driving electrode TE. Driving signals may be applied to the driving electrodes TE sequentially or simultaneously.

[0061] In an example embodiment, drive signals modulated based on different codes can be applied simultaneously to two or more drive electrodes TE, and this is referred to as multi-drive. For example, drive signals with opposite polarities can be applied simultaneously to the first drive electrode Y1 and the second drive electrode Y2, and then drive signals with opposite polarities can be applied simultaneously to the third drive electrode Y3 and the fourth drive electrode Y4.

[0062] The readout circuit 20 may include a plurality of receivers (RX) 21 and an analog-to-digital converter (ADC) 23. The plurality of RX 21 may receive a plurality of sensing signals from the receiving electrodes RE. Each of the plurality of RX 21 may be connected to a corresponding receiving electrode RE and receive a sensing signal, or may be connected to at least two receiving electrodes RE in a time-division manner and receive at least two sensing signals.

[0063] The sensing signal may include an indication of the mutual capacitance C between the driving electrode TE (to which a driving signal is applied) and the receiving electrode RE (through which the sensing signal is received). M The touch signal. For example, when a touch occurs at a sensing node on touch sensor 110, the mutual capacitance C of the sensing node... M It can be reduced, and the level of the sensing signal can be reduced or increased compared to the level before the touch.

[0064] The sensing signal may include noise signals, such as noise from the display or display noise signals. For example, when an image is displayed on a display panel ( Figure 1 When touch sensing is performed during the display period on the 120), the sensing signal may include display noise caused by the display of the image. Depending on the driving scheme of the driving circuit 10, the sensing signal may include touch signal and display noise, or may include display noise excluding touch signal.

[0065] RX 21 can process the sensing signal received from the corresponding receiving electrode RE. For example, RX 21 can convert the sensing signal (e.g., current-to-voltage conversion) or amplify the sensing signal.

[0066] ADC 23 can perform analog-to-digital conversion on the output signals of multiple RX 21 (i.e., the processed sensing signals) and can generate touch data and / or noise data. Multiple touch values ​​corresponding to multiple sensing nodes of touch sensor 110 can be generated and these touch values ​​can be included in a frame of touch data.

[0067] The touch processor 30 can control the overall operation of the TSC 210, and for example, can control the operating timing of the drive circuit 10 and the readout circuit 20. The touch processor 30 can determine whether a touch has occurred and the location of the touch based on touch data and / or noise data output from the ADC 23, or it can determine that a conductive object is approaching the touch sensor 210.

[0068] The touch processor 30 may include a noise processing module 31. The noise processing module 31 may compensate for touch data based on noise data, or it may determine whether to discard touch data based on noise data. For example, the noise processing module 31 may generate compensated touch data by subtracting noise data from the touch data. For instance, when the noise data is equal to or greater than a predetermined value, the noise processing module 31 may discard the touch data without using it to determine whether a touch has occurred, whether a conductive object is approaching, and / or the location of the corresponding touch.

[0069] Figure 3 It is a graph used to describe the components of display noise introduced into the touch sensors stacked on the display panel.

[0070] exist Figure 3 In this display panel 120, a display layer Ldp and a common electrode COM may be included. The display layer Ldp may be formed on a substrate of the display panel 120. The common electrode COM may be formed on the display layer Ldp.

[0071] The display layer Ldp may include multiple source lines S1 to Sd (d is a positive integer). The multiple source lines S1 to Sd may be arranged along a first direction (e.g., the X-axis direction) and extend in a second direction (e.g., the Y-axis direction). Although not shown, the display layer Ldp may include multiple gate lines, and the multiple gate lines may be arranged along the second direction and extend in the first direction. Multiple pixels may be formed at the points where the source lines S1 to Sd and the gate lines intersect each other.

[0072] A parasitic capacitance Cs can form between the source lines S1 to Sd and the common electrode COM. When an image signal is applied to the source lines S1 to Sd, the voltage at the common electrode COM may change due to the parasitic capacitance Cs. A constant voltage, such as ground voltage VSS, can be applied to the common electrode COM. However, due to the RC delay caused by the parasitic resistance Rcom through the common electrode COM, the voltage at the common electrode COM may change when an image signal is applied to the source lines S1 to Sd.

[0073] The touch signal generated by the drive signal Stx provided from TX 11 can be provided to RX 21 as a sensing signal Ssen through the touch signal path. Simultaneously, a parasitic capacitance C can be formed between the common electrode COM and the touch sensor 110. TX Or C RX Display noise generated due to changes in the voltage of the common electrode COM can be transmitted through parasitic capacitance C. RX The resulting display noise path is introduced into the sensing signal Ssen.

[0074] Typically, the parasitic capacitance C RXAs the gap between the touch sensor 110 and the common electrode COM narrows (e.g., in an ultra-thin touchscreen panel), Figure 1 The increase is due to the parasitic capacitance C. RX The increase in the amount of display noise introduced into the sensing signal Ssen can increase, which may make it difficult to distinguish between touch signals and display noise, and difficult to determine whether the change in the sensing signal Ssen is caused by touch input or display noise. According to this example embodiment, TSC( Figure 1 (210) Individually senses the display noise introduced into the touch sensor 110 to generate display noise data, and can process touch data based on the display noise data.

[0075] Figure 4 This is a diagram illustrating a display noise sensing method according to an example embodiment. Figure 4 The display noise sensing method can be derived from Figure 1 and Figure 2 The TSC 210 is executed, and will be referred to below together. Figure 1 and Figure 2 Provide its description.

[0076] Reference Figure 1 , Figure 2 and Figure 4 The TSC 210 can receive a sensing signal Ssen from multiple receiving electrodes of the touch sensor 110 (e.g., first receiving electrode X1 to j-th receiving electrode Xj (j is a positive integer)) without providing driving signals to multiple driving electrodes (e.g., first driving electrode to k-th driving electrode (k is a positive integer)). Multiple TX 11s of the driving circuit 10 can be turned off, and multiple RX 21s of the readout circuit 20 can operate normally and receive the sensing signal Ssen. Because no driving signal is provided to the touch sensor 110, no touch signal based on the driving signal is generated, and the sensing signal Ssen may not include a touch signal. However, noise can be introduced into the touch sensor 110, so the sensing signal Ssen may include noise without a touch signal.

[0077] TSC 210 can perform noise sensing during the display period by receiving sensing signals Ssen from multiple receiving electrodes without providing driving signals to the multiple driving electrodes of touch sensor 110, and the noise included in the sensing signals Ssen can be display noise. As described above, TSC 210 can perform display noise sensing.

[0078] The sensing signal Ssen may include display noise, and the readout circuit 20 can generate display noise data based on the display noise. As the amount of generated display noise increases, the data value of the display noise data can increase.

[0079] The noise processing module 31 can process the touch data generated by touch sensing based on the display noise data generated by display noise sensing.

[0080] According to the display noise sensing method of this example embodiment, since no drive signal is applied to the multiple drive electrodes, the power consumption for display noise sensing can be reduced.

[0081] Figure 5A and Figure 5B This is a timing diagram illustrating the operation method of a TSC according to an example embodiment. Figure 5A and Figure 5B In the image, the horizontal axis represents time.

[0082] Reference Figure 5A and Figure 5B TSC ( Figure 2 (210) can be displayed on the display panel ( Figure 1 Display noise sensing and touch sensing are performed during the display period on the 120).

[0083] For example, DDI ( Figure 1 The 220 can display a frame of image on the display panel 120 in response to the vertical synchronization signal Vsync and can provide image signals to multiple source lines in response to the horizontal synchronization signal Hsync. Therefore, an image can be displayed on the display panel 120.

[0084] The TSC 210 can perform display noise sensing in a first time period P1 and touch sensing in a second time period P2, which is different from the first time period P1. The first time period P1 and the second time period P2 can overlap with the display period during which the image is displayed on the display panel 120 on the time axis. Therefore, display noise sensing and touch sensing can be performed during the display period.

[0085] TSC 210 can be referenced above. Figure 4 The described display noise sensing method performs display noise sensing. TSC 210 can receive timing signals, such as a vertical sync signal Vsync and a horizontal sync signal Hsync, from DDI 220, and can perform display noise sensing in response to the horizontal sync signal Hsync. For example, DDI 220 can provide image signals to multiple source lines of display panel 120 in response to the rising or falling edge of the horizontal sync signal Hsync, and a significant amount of display noise may occur during the initial period of providing the image signal in response to the horizontal sync signal Hsync. Therefore, TSC 210 can improve display noise sensing efficiency by performing display noise sensing at the time when a significant amount of display noise occurs in response to the horizontal sync signal Hsync.

[0086] The TSC 210 can sense one frame from the touch sensor 110 in the second time period P2, such as Figure 5A As shown, or a frame of the touch sensor 110 can be segmented and sensed in the second time period P2, such as Figure 5B As shown.

[0087] Reference Figure 5A The TSC 210 can sense one frame of the touch sensor 110 in the second time period P2, for example, from the first line to the kth line. For example, as Figure 4 As shown, the touch sensor 110 may include first driving electrodes Y1 to k-th driving electrodes Yk, and the TSC 210 can sense the first line to the k-th line in the second time period P2 by driving at least one line at a time from the first driving electrodes Y1 to the k-th driving electrodes Yk. In this respect, the TSC 210 may perform display noise sensing in the first time period P1 before or after a frame of sensing the touch sensor 110.

[0088] Reference Figure 5B The TSC 210 can sense multiple lines of the touch sensor 110 in a single frame during the second time period P2. For example, the TSC 210 can sense the first to eighth lines of the touch sensor 110 in the earliest second time period P2, and the ninth to sixteenth lines of the touch sensor 110 in the second time period P2 after performing display noise sensing. Additionally, the seventeenth to twenty-fourth lines of the touch sensor 110 can be sensed in the second time period P2 after performing display noise sensing again. In this respect, the TSC 210 can perform display noise sensing before, after, and in the middle of performing touch sensing for a frame of the touch sensor 110.

[0089] Noise processing module ( Figure 2 31) can process touch data generated by touch sensing based on display noise data generated by display noise sensing. When processing multiple touch values ​​included in the touch data, the noise processing module 31 can process the touch values ​​based on display noise data generated by display noise sensing performed at a time point closest to the time point when the line corresponding to the touch value is sensed.

[0090] Figure 6 This is a diagram illustrating a display noise sensing method according to an example embodiment. Figure 6 The display noise sensing method can be derived from Figure 1 and Figure 2 The TSC 210 is executed, and will be referred to below together. Figure 1 and Figure 2 Provide its description.

[0091] Reference Figure 1 , Figure 2 and Figure 6 The TSC 210 can simultaneously provide a positive driving signal Stx+ or a negative driving signal Stx- to multiple driving electrodes of the touch sensor 110 (e.g., the first driving electrode Y1 to the kth driving electrode Yk). For example, the TSC 210 can apply a positive driving signal Stx+ to at least one driving electrode and can apply a negative driving signal Stx- to at least one other driving electrode adjacent to at least one driving electrode.

[0092] Figure 7 It shows Figure 6 A diagram of the positive and negative drive signals.

[0093] Reference Figure 7 The positive drive signal Stx+ and the negative drive signal Stx- can include multiple pulse signals during the drive period Td, and the positive drive signal Stx+ and the negative drive signal Stx- can have the same frequency and opposite phase. However, the positive drive signal Stx+ and the negative drive signal Stx- can be sine waves with opposite phase and the same frequency.

[0094] Return to reference Figure 6 Positive drive signals Stx+ and negative drive signals Stx- can be applied alternately to multiple drive electrodes. A positive drive signal Stx+ can be applied to the first drive electrode Y1, and a negative drive signal Stx- can be applied to the second drive electrode Y2. However, positive drive signals Stx+ and negative drive signals Stx- can be applied alternately to at least two drive electrodes. The number of drive electrodes to which positive drive signals Stx+ are applied can be the same as the number of drive electrodes to which negative drive signals Stx- are applied.

[0095] according to Figure 6 In this noise sensing method, when driving signals of opposite polarity are applied to adjacent driving electrodes, the positive touch signal caused by the positive driving signal Stx+ and the negative touch signal caused by the negative driving signal Stx- can cancel each other out. Therefore, the sensing signal output through the multiple receiving electrodes X1 to Xj does not include the touch signal and may include display noise. The display noise is amplified by the positive driving signal Stx+ and the negative driving signal Stx-, and thus, the display noise sensing efficiency can be improved. Furthermore, when the frequencies of the positive driving signal Stx+ and the negative driving signal Stx- change, the display noise can be amplified or attenuated. Therefore, according to the display noise sensing method, the display noise sensing efficiency can be improved.

[0096] Figure 8 This is a flowchart of the operation method of TSC 210 according to an example embodiment. Figure 8 The method can be derived from Figure 1 and Figure 2 The TSC 210 is executed. See also... Figure 2 Provide its description.

[0097] Reference Figure 8 The TSC 210 can generate display noise data by performing display noise sensing during the first time period of the display period (operation S110). The TSC 210 can then refer to the above... Figure 4 or Figure 6 The described display noise sensing method is for sensing display noise.

[0098] As described above, TSC 210 may not apply drive signals to multiple drive electrodes TE. In another example, TSC 210 may apply positive and negative drive signals to the drive electrodes TE. For example, a positive drive signal may be applied to at least one drive electrode TE, and a negative drive signal may be applied to at least one other drive electrode TE adjacent to at least one drive electrode TE.

[0099] The TSC 210 can receive sensing signals from multiple receiving electrodes RE, and the sensing signals may include display noise. The TSC 210 can generate display noise data based on the display noise.

[0100] TSC 210 can generate touch data by performing touch sensing during a second time period of the display period (operation S120). Whenever a drive signal is applied to the drive electrode TE, TSC 210 can sequentially apply the drive signal to the drive electrode TE and receive a sensing signal from the receiving electrode RE. The sensing signal may include a signal, and when display noise occurs, the touch signal may include display noise. TSC 210 can generate touch data based on the sensing signal. The touch data may include a display noise component.

[0101] TSC 210 can process touch data based on display noise data (operation S130). As described above, TSC 210 can generate compensated touch data by subtracting display noise data from the touch data. When the display noise data exceeds a predetermined value, TSC 210 can determine that display noise has occurred and discard the touch data.

[0102] Figure 9 This is a schematic block diagram of a TSC according to an example embodiment. Figure 9 The TSC 210a can be used as Figure 1 The TSC 210 is used. For ease of explanation, the touch sensor 110 will also be shown.

[0103] Reference Figure 9The TSC 210a may include a drive circuit 10, a readout circuit 20a, and a switching circuit (SW) 40. The TSC 210a may also include a reference... Figure 2 The described touch processor 30.

[0104] Because the drive circuit 10 is the same as the reference above Figure 2 The driving circuit 10 described is the same, so descriptions that are the same as those given above will be omitted.

[0105] The readout circuit 20a may include a plurality of first receivers (RX1) 21a, at least one second receiver (RX2) 22a, and an ADC 23. The plurality of RX1 21a can sense touch signals, and the at least one RX2 22a can sense display noise. Therefore, the plurality of RX1 21a can perform touch sensing, while the at least one RX2 22a can perform display noise sensing. The plurality of RX1 21a may be referred to as a touch sensing circuit, and the at least one RX2 22a may be referred to as a display noise reference sensing circuit.

[0106] Multiple RX1 21a can receive multiple first sensing signals Ssen1 from multiple receiving electrodes RE (e.g., first receiving electrodes X1 to j-th receiving electrodes Xj). The first sensing signal Ssen1 may include a touch signal. When display noise occurs, the touch signal may include display noise. Each of the multiple RX1 21a can process and output the received first sensing signal Ssen1. For example, each of the multiple RX1 21a can perform a current-to-voltage conversion on the first sensing signal Ssen1 to generate a sensing voltage, filter the frequency of the sensing voltage, and amplify the gain of the frequency-filtered sensing voltage. In another example, the RX1 21a can perform a current-to-voltage conversion on the first sensing signal Ssen1 to generate a sensing voltage and integrate the sensing voltage.

[0107] RX2 22a can receive a second sensing signal Ssen2 from at least one drive electrode TE selected from the drive electrodes TE that is not subject to a drive signal Stx (hereinafter referred to as the first reference electrode) (e.g., the (k-1)th drive electrode Yk-1). The second sensing signal Ssen2 may include display noise. RX2 22a can process and output the second sensing signal Ssen2.

[0108] ADC 23 can generate touch data and display noise data by performing analog-to-digital conversion on the output signals of multiple RX1 21a and RX2 22a.

[0109] The switching circuit 40 can select a first reference electrode from the driving electrodes TE (e.g., the first driving electrodes Y1 to the k-th driving electrodes Yk) to which the second sensing signal Ssen2 is output. The switching circuit 40 can also select a first reference electrode from the driving electrodes TE that is not to which a driving signal Stx is applied. Therefore, the switching circuit 40 can electrically connect the first reference electrode selected from the driving electrodes TE that is not to which a driving signal Stx is applied to RX2 22a.

[0110] When performing touch sensing, at least one drive electrode TE can be sequentially applied a drive signal Stx to the drive electrode TE at a time, and thus these drive electrodes TE can be driven sequentially. The switching circuit 40 can change the first reference electrode so that another drive electrode TE that is not applied a drive signal Stx can be connected to RX2 22a as the first reference electrode.

[0111] For example, when a drive signal Stx is applied to the first drive electrode Y1, the switching circuit 40 can select one of the drive electrodes Y2 to Yk from the second drive electrode to the kth drive electrode that has not been applied a drive signal Stx as the first reference electrode. The switching circuit 40 can also select the (k-1)th drive electrode Yk-1, which is spaced apart from the first drive electrode Y1, as the first reference electrode. For example, when a drive signal Stx is applied to the second drive electrode Y2, the switching circuit 40 can select one of the drive electrodes Y1 and Y3 to Yk from the third drive electrode to the kth drive electrode that has not been applied a drive signal Stx as the first reference electrode and connect the first reference electrode to RX2 22a.

[0112] In an example embodiment, multiple RX1 21a and at least one RX2 22a may also receive a third sensing signal Ssen3 from at least one drive electrode TE (hereinafter referred to as the second reference electrode) (e.g., the k-th drive electrode Yk) that is not subjected to a drive signal Stx. The third sensing signal Ssen3 may include display noise. The second reference electrode through which the third sensing signal Ssen3 is received is different from the first reference electrode through which the second sensing signal Ssen2 is received.

[0113] Multiple RX1 21a can generate touch sensing signals based on a first sensing signal Ssen1 and a third sensing signal Ssen3, and at least one RX2 22a can generate a display noise reference signal based on a second sensing signal Ssen2 and a third sensing signal Ssen3. ADC 23 can generate touch data and display noise data by performing analog-to-digital conversion on the touch sensing signals and the display noise reference signal.

[0114] The switching circuit 40 can select a second reference electrode from the drive electrodes Y1 to Yk to output the third sensing signal Ssen3. The switching circuit 40 can also select a second reference electrode from the drive electrodes that has not been given a drive signal Stx.

[0115] During touch sensing, as the driving electrode TE is driven sequentially, the switching circuit 40 can change the second reference electrode, so that the driving electrode TE, which has never been given a driving signal Stx, outputs the third sensing signal Ssen3.

[0116] For example, when a drive signal Stx is applied to the first drive electrode Yl, the (k-1)th drive electrode Yk-1 can be selected as the first reference electrode and a second sensing signal Ssen2 can be received from the (k-1)th drive electrode Yk-1. Conversely, the kth drive electrode Yk can be selected as the second reference electrode and a third sensing signal Ssen3 can be received from the kth drive electrode Yk. However, the kth drive electrode Yk can be selected as the first reference electrode, and the (k-1)th drive electrode Yk-1 can be selected as the second reference electrode.

[0117] Although Figure 9 Two adjacent driving electrodes TE (e.g., the (k-1)th driving electrode Yk-1 and the kth driving electrode Yk) are selected as the first reference electrode and the second reference electrode, respectively. However, another driving electrode TE may be disposed between the first reference electrode and the second reference electrode, and at least one of the first reference electrode and the second reference electrode may include two or more adjacent driving electrodes TE.

[0118] Figure 10 This is a schematic diagram illustrating the operation of the readout circuit according to an example embodiment and a diagram of the readout circuit.

[0119] Reference Figure 10 The readout circuit 20a may include multiple RX1 21a, RX2 22a and ADC 23. (See reference...) Figure 9 The described readout circuit 20a may include multiple RX1 21a. Because the operation of multiple RX1 21a is identical, for ease of explanation, ... Figure 10 An RX1 21a connected to the first receiving electrode X1 is shown in the figure.

[0120] As shown above (refer to the reference) Figure 3 As described, a parasitic capacitance C can be formed between the common electrode COM and the driving electrodes (e.g., the (k-1)th driving electrode Yk-1 and the kth driving electrode of the display panel 120). TX1 and C TX2 Furthermore, a parasitic capacitance C can be formed between the common electrode COM and the receiving electrode (e.g., the first receiving electrode X1).RX .

[0121] The touch signal generated by the drive signal Stx provided from TX 11 can be provided as the first sensing signal Ssenl to RX1 21a connected to the first receiving electrode X1. When display noise occurs in the common electrode COM, the display noise can be transmitted through the parasitic capacitance C. RX The resulting noise path is introduced into the first receiving electrode X1 and can be included in the first sensing signal Ssen1. Therefore, the first sensing signal Ssen1 can include touch signal and display noise.

[0122] The second sensing signal Ssen2, output from the first reference electrode (e.g., the (k-1)th driving electrode Yk-1), can be provided to RX2 22a. Display noise can be mitigated by parasitic capacitance C. TX1 The formed noise path is introduced into the (k-1)th drive electrode Yk-1, and the noise is shown to be provided to RX2 22a as a second sensing signal Ssen2.

[0123] The third sensing signal Ssen3, output from the second reference electrode (e.g., the k-th driving electrode Yk), can be provided to RX1 21a and RX2 22a. Display noise can be reduced by parasitic capacitance C. TX2 The resulting noise path is introduced into the k-th driving electrode Yk, and the noise is shown to be provided as a third sensing signal Ssen3 to RX1 21a and RX2 22a.

[0124] RX1 21a may include a first current amplifier CA1, a first filter FT1, and a first gain amplifier GA1. RX1 21a may also include a first switch SW1.

[0125] The first current amplifier CA1 may include a first input terminal I11 and a second input terminal I12. It can receive a first sensing signal Ssen1 through the first input terminal I11 and a third sensing signal Ssen3 through the second input terminal I12. The first current amplifier CA1 can amplify the current quantity corresponding to the difference between the first sensing signal Ssen1 and the third sensing signal Ssen3 and convert the amplified current quantity into a first sensing voltage.

[0126] The first filter FT1 can filter the frequency of the first sensed voltage output from the first current amplifier CA1. For example, the first filter FT1 can be implemented as a low-pass filter that allows frequency bands below or equal to the first frequency to pass through, and therefore, the first filter FT1 allows frequency components of the first sensed voltage below or equal to the first frequency to pass through and blocks frequency components above the first frequency. For example, the first filter FT1 can remove high-frequency noise from the first sensed voltage. The first filter FT1 can output a first sensed voltage from which high-frequency noise has been removed.

[0127] The first gain amplifier GA1 can amplify the first sense voltage output from the first filter FT1. For example, the first gain amplifier GA1 can have a first gain and can amplify the amplitude of the first sense voltage by the first gain. The first gain amplifier GA1 can output the amplified first sense voltage as a touch sensing signal.

[0128] The first switch SW1 can be turned on or off in response to the first enable signal EN1. This can be controlled from the touch processor ( Figure 2 30) Receives the first enable signal EN1. When the first switch SW1 is turned on, a touch sensing signal can be provided to ADC 23.

[0129] RX2 22a may include a second current amplifier CA2, a second filter FT2, and a second gain amplifier GA2. RX222a may also include a second switch SW2.

[0130] The second current amplifier CA2 may include a first input terminal I21 and a second input terminal I22. It can receive a second sensing signal Ssen2 through the first input terminal I21 and a third sensing signal Ssen3 through the second input terminal I22. The second current amplifier CA2 can amplify the current quantity corresponding to the difference between the second sensing signal Ssen2 and the third sensing signal Ssen3 and convert the amplified current quantity into a second sensing voltage.

[0131] The second filter FT2 can filter the frequency of the second sensed voltage output from the second current amplifier CA2. For example, the second filter FT2 can be implemented as a low-pass filter that allows frequency bands below or equal to the second frequency to pass through, and therefore, the second filter FT2 allows frequency components of the second sensed voltage below or equal to the second frequency to pass through and blocks frequency components above the second frequency. For example, the second filter FT2 can remove high-frequency noise from the second sensed voltage. The second filter FT2 can output a second sensed voltage from which high-frequency noise has been removed. The second frequency of the second filter FT2 can be the same as or different from the first frequency of the first filter FT1.

[0132] The second gain amplifier GA2 can amplify the second sensed voltage output from the second filter FT2. For example, the second gain amplifier GA2 can have a second gain and can amplify the amplitude of the second sensed voltage by a second gain. The second gain amplifier GA2 can output the amplified second sensed voltage as a display noise reference signal. The second gain of the second gain amplifier GA1 can be the same as or different from the first gain of the first gain amplifier GA1.

[0133] The second switch SW2 can be turned on or off in response to the second enable signal EN2. This can be controlled from the touch processor ( Figure 2 30) Receives the second enable signal EN2. When the third switch SW3 is turned on, a display noise reference signal can be provided to ADC 23.

[0134] ADC 23 can convert multiple touch sensing signals received sequentially from multiple RX1 21a into multiple touch values. Therefore, it can generate values ​​including those from the touch sensor (…). Figure 2 The ADC 23 can also convert the display noise reference signal received from RX2 22a into display noise data.

[0135] As described above, the readout circuit 20a according to the example embodiment may include an RX2 21a for display noise sensing, separate from the RX1 20a for performing touch sensing. When the RX1 20a performs touch sensing, the RX2 21a may simultaneously perform display noise sensing. Therefore, the RX2 21a can detect changes in display noise in real time.

[0136] Figure 11 This is a schematic diagram illustrating the operation of the readout circuit according to an example embodiment and a diagram of the readout circuit. Figure 11 The readout circuit 20b can be Figure 10 A modified example of the readout circuit 20a. Therefore, refer to the above. Figure 10 The given description can also be applied to Figure 11 The operation of the readout circuit 20b.

[0137] Reference Figure 11 The readout circuit 20b may include RX1 21b, RX2 22b and ADC 23.

[0138] RX1 21b may include a first current amplifier CA1, a first filter FT1, a first gain amplifier GA1, a differential amplifier CA, and a first switch SW1. RX2 22b may include a second current amplifier CA2, a second filter FT2, and a second gain amplifier GA2. (As per...) Figure 10Compared to the readout circuit 20a, RX1 21b may also include a differential amplifier CA.

[0139] The differential amplifier CA amplifies the difference between the touch sensing signal (output from the first gain amplifier CA1) and the display noise reference signal (output from the second gain amplifier GA2 of RX2 22b), and outputs a compensated touch sensing signal. Therefore, display noise can be removed from the touch sensing signal.

[0140] ADC 23 can convert the compensated touch sensing signal output from differential amplifier CA into touch values. ADC 23 can sequentially receive multiple touch sensing signals from multiple RX1 21a and convert the touch sensing signals into multiple touch values. Therefore, touch data from which display noise has been removed can be generated.

[0141] Figure 12 This is a flowchart of the operation method of TSC 210 according to an example embodiment. Figure 12 The operating method of TSC 210 can be provided by Figure 1 and Figure 2 TSC 210, Figure 11 The readout circuit 20a and Figure 12 The readout circuit 20b is executed.

[0142] Reference Figure 12 TSC 210 can apply a drive signal to at least one of the multiple drive electrodes (operation S210).

[0143] Multiple RX1s configured in the TSC 210 (e.g., Figure 11 21a) can perform touch sensing (operation S220). The plurality of RX1 21a can perform touch sensing by receiving and processing a first sensing signal from a corresponding receiving electrode among the plurality of receiving electrodes.

[0144] At least one RX2 (e.g., set in TSC 210) Figure 11 22a) can perform display noise sensing (operation S230). At least one RX2 22a can perform display noise sensing by receiving and processing a second sensing signal from at least one other driving electrode among the driving electrodes that has not been given a driving signal. Touch sensing of operation S220 can be performed simultaneously with display noise sensing of operation S230, and can be performed when an image is displayed on the display panel ( Figure 1 The operation method of TSC 210 according to the example embodiment is executed during the display period on (120).

[0145] In an example embodiment, TSC 210 can generate touch data based on a touch sensing signal sensed by touch sensing, and can generate display noise data based on a display noise reference signal sensed by display noise. TSC 210 can process the touch data based on the display noise data.

[0146] In an example embodiment, TSC 210 can generate a compensated touch sensing signal by removing a display noise reference signal sensed based on display noise from the touch sensing signal sensed based on touch sensing. TSC 210 can then generate touch data from which display noise has been removed based on the compensated touch sensing signal.

[0147] Figure 13 A block diagram schematically illustrates a touchscreen driving circuit 200b according to an example embodiment, and Figure 14 It shows the setting Figure 13 The flowchart illustrates the operation of TSC 210b and DDI 220b in the touchscreen driver circuit 200b. The touchscreen driver circuit 200b can be applied to... Figure 1 Touchscreen driver circuit 200.

[0148] Reference Figure 13 The touchscreen driver circuit 200b may include TSC 210b and DDI 220b. (See reference...) Figure 1 As described, the TSC 210b can send data to a touch sensor ( Figure 1 The DDI 220b provides a drive signal to the host computer, and receives a sensing signal from the touch sensor 110b according to the drive signal to perform touch sensing, as well as detect the occurrence of touch input (or proximity) and / or calculate touch coordinates. Figure 1 The received image data (300) is converted into an image signal and the display panel is driven based on the image signal. Figure 1 (120), thereby displaying an image corresponding to the image data on the display panel 120.

[0149] DDI 220b may include an image data receiver 221, an image data analyzer 222, an image state information generator 223, a reference map generator 224, and a touch sensing offset generator 225, and TSC 210 may include a noise remover 211.

[0150] Refer to together Figure 13 and Figure 14 The image data receiver 221 can be obtained from the host ( Figure 1 Image data receiver 221 receives image data line by line (operation S311).

[0151] Image data analyzer 222 can analyze the received image data (operation S312). For example, image data analyzer 222 can calculate the data difference between each row of the image data, that is, the data difference between the previous row and the current row.

[0152] Image state information generator 223 can generate image state information indicating the state of image data (operation S313). For example, when there is a data change equal to or greater than a threshold level between rows of image data, image state information generator 223 can generate a condition flag CF indicating that a change in image data has occurred as image state information. DDI 220b can provide image state information, such as the condition flag CF, to TSC 210b.

[0153] Reference graph generator 224 can generate a voltage graph indicating the amount of voltage change causing display noise or an impedance graph indicating impedance change based on image data (operation S315). Reference graph generator 224 may include a coupling voltage graph generator (CVMG) and / or an impedance graph generator (IPMG). The coupling voltage graph generator (CVMG) can generate a coupling voltage graph including the coupling voltage at multiple points on the display panel 120. The impedance graph generator (IPMG) can generate an impedance graph representing the impedance at multiple points on the display panel 120. The impedance graph generator (IPMG) can generate an impedance graph based on the amount of power supply voltage drop at multiple points on the display panel 120, based on image data (e.g., the amount of IR drop of the power supply voltage (or IR drop graph)). (See later...) Figure 14 The method for generating coupled voltage maps is described, and will be referred to later. Figures 15 to 17 Describe the method for generating impedance maps.

[0154] Touch sensing offset generator 225 can calculate touch sensing offset OFS based on at least one of a voltage map (e.g., a coupling voltage map) and an impedance map generated by reference map generator 224. Touch sensing offset OFS may include an offset value indicating the amount of change in touch value due to the occurrence of display noise. Touch sensing offset generator 225 can calculate the offset value according to the resolution of touch sensor 110, i.e., the offset value corresponding to each sensing node of touch sensor 110. DDI 220b can provide touch sensing offset OFS to TSC 210b (operation S317).

[0155] TSC 210b can perform touch sensing (operation S321) and generate touch data based on the touch sensing (operation S322). When image status information received from DDI 220b indicates an image change, TSC 210b can determine that display noise may have occurred.

[0156] TSC 210b can compensate for touch data by applying a touch sensing offset (OFS) to the touch data (operation S323). For example, noise remover 211 can compensate for touch data by subtracting the offset value from the touch data. As a result, display noise can be removed from the touch data.

[0157] The TSC 210b can determine whether a touch has occurred (or whether a conductive object is approaching) or calculate touch coordinates based on the compensated touch data (operation S324).

[0158] As described above, in the touchscreen driving circuit 200b according to the example embodiment, DDI 220b generates a voltage map by calculating the voltage changes at multiple points on the display panel 120 that cause display noise based on image data, calculates the touch sensing offset OFS based on the voltage map, and provides the touch sensing offset OFS to TSC 210b. TSC 210b can compensate for touch data based on the touch sensing offset OFS, thereby removing display noise from the touch data.

[0159] The components included in DDI 220b and TSC 210b (e.g., image data receiver 221, image data analyzer 222, image state information generator 223, reference map generator 224, touch sensing offset generator 225, and noise remover 211) can be implemented as hardware components, software components, or a combination of hardware and software. For example, the components included in DDI 220 and TSC 210 can be implemented as hardware logic circuits. In another implementation, the components included in DDI 220 and TSC 210 can be implemented as programs, each program including multiple instructions, which can be stored in memory provided in DDI 220b and / or TSC 210b and can be executed by a processor provided in DDI 220b and / or TSC 210b.

[0160] TSC 210b and DDI 220b can be integrated onto a single semiconductor chip or implemented separately on multiple semiconductor chips. The semiconductor chip integrating TSC 210b and DDI 220b can be referred to as TDDI. In TDDI, TSC 210b and DDI 220b can each include a communication port for sending or receiving data or signals to and from each other. DDI 220b can send image status information, such as condition flags CF and touch sensing offset OFS, to TSC 210b through the communication port of an application setting interface scheme. Additionally, DDI 220b can send display status information DS to TSC 210b through the communication port. For example, during standby periods when no image is displayed on display panel 120, DDI 220b can provide a standby signal as display status information DS to TSC 210b.

[0161] Figure 15 This is a flowchart of a method for generating a coupled voltage map according to an example embodiment. Figure 15 The method can be derived from Figure 13 The coupled voltage map generator CVMG is executed.

[0162] Reference Figure 15 The Coupled Voltage Map Generator (CVMG) can convert pixel data into voltages (operation S410). The CVMG can include mapping information representing voltage values ​​corresponding to the pixel data, or can receive mapping information from an external source (e.g., host 300). The CVMG can convert pixel data into voltages (e.g., digital signals representing voltages) based on the mapping information. Multiple pixel data lines included in the image data can be converted into multiple voltages.

[0163] The Coupled Voltage Map Generator (CVMG) can calculate the coupled voltage for each row based on the converted voltage (operation S420). The CVMG calculates the coupled voltage by comparing the voltage corresponding to the pixel data of the previous row with the voltage corresponding to the pixel data of the current row.

[0164] The coupling voltage diagram generator CVMG can determine a ratio diagram indicating the applied ratio of the coupling voltage based on the location (operation S430).

[0165] The coupling voltage diagram generator CVMG can calculate the coupling voltage based on the voltage calculated in operation S420 and the ratio diagram determined in operation S430 (operation S440).

[0166] The coupling voltage ΔVn can be generated according to Equation 1:

[0167] Equation 1

[0168]

[0169] In Equation 1, the values ​​of α, β, and γ can be determined based on optically and visually measured values ​​during the calculation of the coupling voltage.

[0170] In Equation 1, α represents the applied ratio of the coupling voltage at the current row (e.g., the nth row). This can be determined by the coupling voltage ΔV that causes the coupling. n The value of α is determined by the degree to which the voltage range changes. The value of α can be increased or decreased based on whether the voltage increases or decreases.

[0171] In Equation 1, the value of γ can vary depending on the position of the current row on the display panel 120.

[0172] In Equation 1, β represents the effect of the previous row, for example, the applied ratio of the coupling voltage based on the position of the current row on the display panel 120. The value of β can be set according to the stable length of the ripple caused by the coupling voltage of the previous row.

[0173] In equation 1, V n This represents the voltage of the pixel in the current row (e.g., the nth row).

[0174] In equation 1, V n-1 This represents the voltage of the pixel in the previous row, for example, the coupling voltage at the previous row or the (n-1)th row.

[0175] In equation 1, ∑(V n -V n-1 This represents the sum of voltage differences between the current row and the previous row, corresponding to the pixels included in a row.

[0176] In Equation 1, #Hpx represents the number of pixels included in a row.

[0177] Therefore, in equation 1, The coupling voltage of the current row is expressed as the average value of the voltage difference of the current row.

[0178] The coupling voltage diagram generator CVMG can generate coupling voltage diagrams that include coupling voltages calculated for multiple locations on the display panel (operation S450).

[0179] Figure 16 This is a diagram showing the structure of the power cord for the display panel 120.

[0180] Reference Figure 16The power line that transmits the power supply voltage Vdd from the display panel 120 may include an external power line PLe and an internal power line PLi. The external power line PLe may include external circuitry that provides the power supply voltage Vdd, for example, from DDI (…). Figure 13 The internal power supply line PLi may include wires formed in the form of a mesh grid inside the display panel 120.

[0181] The external power line PLe can be modeled as parasitic resistances Ri and Ro, and the internal power line PLi can be modeled as multiple parasitic resistances Rv and Rh. Pixels PX can be arranged at lattice points on the internal power line PLi, and each pixel PX can include a light-emitting device like an organic light-emitting diode (OLED), a driving transistor Td, and a storage capacitor Cst. Image signals, such as data voltage Vd(n,m), can be applied to the pixel PX, and this data voltage Vd(n,m) can be stored in the storage capacitor Cst. A pixel current Ip(n,m) based on the data voltage Vd(n,m) can be supplied to the OLED via the driving transistor Td. Here, n and m are positive integers, where n represents the line, such as a row, on the display panel 120 where the pixel PX is located, and m represents the column where the pixel PX is located.

[0182] The voltage drop of the power supply voltage Vdd caused by the parasitic resistance present in the power supply line, and the pixel current Ip which varies depending on the input image, such as the data voltage Vd, can be referred to as the IR drop or loading effect.

[0183] IR drop can be categorized into global IR drop and local IR drop. Global IR drop occurs in the external power line PLi due to the parasitic resistances Ri and Ro of the external power line and the current It flowing through it. This IR drop can affect all pixels PX of the display panel 120. In the internal power line PLi, the magnitude of the IR drop varies depending on the location of the current flowing through it. Therefore, the magnitude of the IR drop affecting the pixel PX varies, and this can be termed local IR drop.

[0184] Depending on the image signal input to the display panel 120 (e.g., data voltage Vd and brightness setting), global IR drop and local IR drop can occur differently. IR drop affects display noise, thus affecting touch data.

[0185] The global IR reduction Vgid can be expressed by Equation 2:

[0186] Equation 2

[0187] Vgid=It×(Ri+Ro)

[0188] See below for reference. Figure 17 and Figure 18 Describe the local IR drop.

[0189] Figure 17 This is a modeling diagram showing the internal structure of the display panel 120, and Figure 18 It is a graph showing a series of decreasing power supply voltages on the display panel 120.

[0190] Reference Figure 17 The display panel 120 may include multiple data lines DL and multiple scan lines SL, wherein the data lines DL may extend in a second direction (e.g., the Y-axis direction), and the scan lines SL may extend in a first direction (e.g., the X-axis direction). The data lines DL and scan lines SL may be referred to as source lines and gate lines, respectively.

[0191] Multiple pixels PX can be arranged in rows and columns. For example, pixels PX can be arranged in N rows and M columns (N and M are positive integers). Data lines DL and scan lines SL can be connected to each pixel in the pixel PX. N scan signals Vg-1 to Vg-N can be applied sequentially to the N scan lines SL. M data voltages Vd-1 to Vd-M can be applied simultaneously to the M data lines DL. M data voltages Vd-1 to Vd-M can be applied to the M pixels PX connected to the scan lines SL to which scan signals have been applied. Pixel current can flow according to the applied data voltage. For example, a data voltage Vd-M can be applied to the pixel located at the nth row and Mth column, and the pixel current Ip(N, M) according to the data voltage Vd-M can flow through the driving transistor. The pixel current flowing through each pixel PX can flow through the internal power line PLi, and therefore the local IR drop Vlid at multiple points can be different from each other.

[0192] The local IR drop Vlid(n,m) that affects the power supply voltage applied to the pixel PX located in the nth row and mth column can be expressed by Equation 3:

[0193] Equation 3

[0194]

[0195] In Equation 3, Rp represents the parasitic resistance at each point of the internal power line Pli, Ip represents the pixel current, and s and r can be positive integers.

[0196] Figure 18This is a graph showing the power supply voltage Vdd at various points in a column (e.g., column M) that reduces the local IR drop. The horizontal axis corresponds to a second direction, such as the Y-axis, and can represent the distance to the point where the power supply voltage Vdd is applied. As the distance from the point where the power supply voltage Vdd is applied increases, the magnitude of the local IR drop can increase. Therefore, as the distance from the point where the power supply voltage Vdd is applied increases, the power supply voltage can decrease.

[0197] The power supply voltage Vdd′(n,m) supplied to each pixel PX can be expressed by Equation 4:

[0198] Equation 4

[0199] Vdd′(n,m)=Vdd-(Vgid+Vlid(n,m))

[0200] Impedance map generator (e.g., Figure 13 The IPMG (Impedance Map Generator) can calculate the pixel current Ip flowing through each pixel PX based on the data voltage applied to each pixel PX, and can calculate the IR drop, representing the change in power supply voltage VDD at multiple points on the display panel 120, based on the pixel current Ip and parasitic capacitance of the pixel PX using Equations 2 to 4, thereby generating an IR drop map. The IPMG can then generate an impedance map representing the impedance at multiple points on the display panel 120 based on the IR drop map.

[0201] Figure 19 This is a schematic block diagram of a touchscreen driving circuit 200c according to an example embodiment.

[0202] Reference Figure 19 The touchscreen driver circuit 200c may include TSC 210c and DDI 220c. TSC 210c and DDI 220c may be integrated into a single semiconductor chip or in different semiconductor chips.

[0203] The DDI 220c may include an image data receiver 221, an image data analyzer 222, an image status information generator 223, and a reference image generator 224.

[0204] The TSC 210c may include a touch-sensing offset generator 212 and a noise remover 211. (As with...) Figure 13 In contrast, the touch sensing offset generator 212 can be set in the TSC 210c instead of the DDI 220c.

[0205] The DDI 220c can provide the TSC 210c with a reference map RM, including at least one of a coupling voltage map and an impedance map. The TSC 210c's touch sensing offset generator 212 can calculate, based on the reference map RM, parameters related to the touch sensor (…). Figure 1 The touch sensing offset is the offset value corresponding to the multiple sensing nodes of (110).

[0206] The noise remover 211 can generate compensated touch data by applying a touch sensing offset to the touch data generated by touch sensing.

[0207] Figure 20 This is a flowchart of the operation method of TSC 210 according to an example embodiment.

[0208] Reference Figure 20 The TSC210 can determine whether it is in display mode (operation S210). For example, the TSC210 can determine whether it is in display mode from the DDI (…). Figure 1 (220) receives status information indicating the display status and determines whether it is in display status (where the image is displayed on the display panel). Figure 1 (120) on).

[0209] Once it is determined that the device is in a display state, TSC 210 can perform a first touch sensing operation to obtain touch data and display noise data (operation S220). The first touch sensing is a touch sensing operation that takes display noise into account, and may include performing a reference... Figures 4 to 8 and Figures 9 to 12 The description of display noise sensing, or as referenced Figures 13 to 19 The described application is based on the offset value of the amount of voltage change that causes display noise. For example, the TSC 210 can obtain display noise data by display noise sensing at the same time as touch sensing or at a different time than touch sensing, or it can obtain display noise data based on the amount of voltage change or touch sensing offset received from the DDI 220.

[0210] The TSC 210 can process touch data based on display noise data (operation S230).

[0211] Simultaneously, when it is determined that the device is not in a display state, TSC 210 can obtain touch data by performing a second touch sensing operation that does not consider display noise (operation S240). Since the device is not in a display state, it can be assumed that no display noise has occurred. Therefore, TSC 210 does not need to perform the reference... Figures 4 to 8 and Figures 9 to 12 The described display noise sensing, or may be disregarded as in the reference. Figures 13 to 19 The application described is based on the offset value of the amount of voltage change that causes display noise.

[0212] TSC 210 can determine whether a touch has occurred or calculate touch coordinates based on touch data or processed touch data (operation S250). In an example embodiment, TSC 210 can determine whether a conductive object is approaching touch sensor 110 based on touch data processed by touch.

[0213] Figure 21 and Figure 22 This is a diagram illustrating an example implementation of a touchscreen driver circuit according to an exemplary embodiment.

[0214] Reference Figure 21 The touchscreen driving circuit 200 may include TSC 210 and DDI 220. In an example embodiment, TSC 210 and DDI 220 may be implemented as separate semiconductor chips. In an example embodiment, at least one of TSC 210 and DDI 220 may be implemented as multiple semiconductor chips.

[0215] The TSC 210 and DDI 220 can operate under the control of the host 300, and the DDI 220 can receive image data IDT from the host 300 and drive the display panel. Figure 1 (120) to display an image on display panel 120 according to image data IDT.

[0216] The TSC 210 can scan touch sensors ( Figure 1 The touch sensor 110 calculates touch coordinates Txy based on the sensing signal received from the touch sensor 110, or detects touch input (or an approaching conductive object). The TSC 210 can provide touch coordinates Txy or proximity notification signal N_px to the host 300.

[0217] Reference Figure 21 The TSC 210 may include an analog front-end (AFE), a touch processor, a clock generator, and a voltage generator.

[0218] Additionally, TSC 210 may include interface circuitry for communicating with host 300 and DDI 220. As a non-limiting example, the interface circuitry for communicating with host 300 may be implemented as one of a variety of interfaces including: Universal Serial Bus (USB) interface, Universal Flash Memory (UFS) interface, Multimedia Controller (MMC) interface, Embedded MMC (eMMC) interface, Peripheral Component Interconnect Fast (PCIe) interface, Advanced Technology Attachment (ATA) interface, Serial Advanced Technology Attachment (SATA) interface, Parallel Advanced Technology Attachment (PATA) interface, Small Computer System Interface (SCSI), Serial Attached SCSI (SAS), Enhanced Small Disk Interface (ESDI), Integrated Drive Electronics (IDE) interface, and High Speed ​​Serial Interface; and the interface circuitry for communicating with DDI 220 may be implemented as one of: Universal Asynchronous Receiver Transmitter (UART) interface, Internal Integrated Circuit (I2C) interface, Serial Peripheral Interface (SPI), Mobile Industrial Processor Interface (MIPI), and Embedded Display Port (eDP) interface.

[0219] AFE may include a drive circuit ( Figure 2 10) and readout circuit ( Figure 2 20). An AFE may also include switching circuitry ( Figure 9 40). Drive circuit ( Figure 2 10) and readout circuit ( Figure 2 20) can perform the above-mentioned display noise sensing and touch sensing.

[0220] The clock generator can generate clock signals used internally in the TSC 210, such as clock signals provided to the drive circuitry and readout circuitry.

[0221] A voltage generator can generate the voltage used in an AFE.

[0222] The touch processor can control the overall operation of the TSC 210, and the touch processor can include... Figure 2 Noise processing module 31 and / or Figure 13 The noise remover 211. The touch processor may also include... Figure 19 Touch sensing offset generator 212.

[0223] As referenced above Figure 2 The operation of the drive circuit, readout circuit, and touch processor is described, and therefore descriptions identical to those will be omitted.

[0224] The DDI 220 may include a clock generator, a display controller, a voltage generator, a gamma block, SRAM, a gate driver, and a source driver. Additionally, the DDI 220 may include interface circuitry for communication with the host 300 and the touch driver circuitry TDI.

[0225] The clock generator can generate clock signals used internally in the DDI 220, such as clock signals provided to the source and gate drivers.

[0226] A voltage generator can generate voltages used in gate drivers and source drivers.

[0227] The gamma block can generate multiple grayscale voltages corresponding to the multiple grayscale levels that a pixel value can have and provide them to the source driver.

[0228] SRAM can store image data IDT received from host 300. For example, SRAM can store multiple lines of image data IDT or the image data IDT of a frame and provide the image data IDT to the source driver line by line.

[0229] The gate driver can sequentially drive the gates located on the display panel ( Figure 1 Multiple scan lines in (120) provide scan signals.

[0230] The source driver can simultaneously provide image signals, such as data voltages, to multiple data lines disposed in the display panel 120.

[0231] The display controller can control the overall operation of the DDI 220. In an example embodiment, the display controller may include... Figure 13 The image data receiver 221, image data analyzer 222, image state information generator 223, reference image generator 224, and touch sensing offset generator 225 are included.

[0232] In the example embodiment, DDI 220 and TSC 210 can communicate with each other, and DDI 220 and TSC 210 can include interface circuitry for communication. As a non-limiting example, the interface circuitry for communication between the DDI 220 and the TSC 210 can be implemented as one of a variety of interfaces including: Universal Serial Bus (USB) interface, Universal Flash Memory (UFS) interface, Multimedia Controller (MMC) interface, Embedded MMC (eMMC) interface, Peripheral Component Interconnect Fast (PCIe) interface, Advanced Technology Attachment (ATA) interface, Serial Advanced Technology Attachment (SATA) interface, Parallel Advanced Technology Attachment (PATA) interface, Small Computer System Interface (SCSI), Serial Attached SCSI (SAS), Enhanced Small Disk Interface (ESDI), Integrated Drive Electronics (IDE) interface, and High Speed ​​Serial Interface. Furthermore, the interface circuitry for communication with the DDI 220 can be implemented as one of the following: Universal Asynchronous Receiver Transmitter (UART) interface, Internal Integrated Circuit (I2C) interface, Serial Peripheral Interface (SPI), Mobile Industrial Processor Interface (MIPI), and Embedded Display Port (eDP) interface.

[0233] Reference Figure 22 The touchscreen driver circuit 200 may include a TSC 210 and a DDI 220. The touchscreen driver circuit 200 may be integrated into a single semiconductor chip, and the touchscreen driver circuit 200 may be referred to as a touch DDI (TDDI).

[0234] The TSC 210 may include an AFE and a device for driving a touch sensor. Figure 1 The DDI 220 may include a gate driver, source driver, SRAM, gamma block, and a touch processor for driving the display panel (110). Figure 1 The display controller (120). The TSC 210 or DDI 220 may include a clock signal generator for generating at least one clock signal used in the touchscreen driver circuit 200 and a voltage generator for generating multiple voltages. Although Figure 21 The clock generator is shown to be located in the TSC210 and the voltage generator in the DDI 220, but this can be implemented differently. The touchscreen driver circuit 200 may also include interface circuitry for communication with the host 300.

[0235] TSC 210 and DDI 220 can communicate with each other within the touchscreen driver circuit 200, and TSC 210 and DDI 220 can each include ports for communicating with each other, such as a first port P1 and a second port P2. Clock signals and voltages can be sent / received via data lines connected via the first port P1 and the second port P2, and various types of data can be sent / received, for example, as shown in the reference above. Figure 13 and Figure 19 The described touch sensing offset OFS and image state information (e.g., condition flag CF, display state information DS, or reference image RM).

[0236] In summary, the parasitic capacitance between the display panel and the touch sensor can increase as the distance between them becomes very small (e.g., as touchscreens become ultra-thin), and display noise that occurs during display can be introduced into the touch sensor by the parasitic capacitance. This display noise can degrade touch sensing sensitivity. Furthermore, when the touch sensor performs proximity sensing, the signal sensed by the touch sensor can be very weak, and therefore, it may be difficult to distinguish between changes in the sensing signal caused by a conductive object approaching the touch sensor and changes in the sensing signal caused by display noise introduced into the touch sensor.

[0237] As described above, the example embodiments may provide a touch sensor controller for improving touch sensing sensitivity, a method for operating the touch sensor controller, and a touch screen driving circuit including the touch sensor controller.

[0238] Example embodiments have been disclosed herein, and although specific terminology has been used, they are to be used and interpreted in a general and descriptive sense only and not for limiting purposes. In some instances, as will be apparent to those skilled in the art from the time of filing of this application, features, characteristics, and / or elements described with particular embodiments may be used alone or in combination with features, characteristics, and / or elements described together with other embodiments, unless otherwise specifically indicated. Therefore, those skilled in the art will understand that various changes in form and detail may be made without departing from the spirit and scope of the invention as set forth in the appended claims.

Claims

1. A touch sensor controller for driving a touch sensor, the touch sensor being stacked on a display panel and including driving electrodes and receiving electrodes intersecting the driving electrodes, the touch sensor controller comprising: A driving circuit configured to sequentially provide driving signals to the driving electrodes; A readout circuit configured to generate touch data based on a first sensing signal received from the receiving electrode in response to the drive signal, and simultaneously generate display noise data based on a second sensing signal received from a first drive electrode among the drive electrodes to which no drive signal has been applied. A touch processor configured to determine, based on the touch data and the display noise data, whether a touch input has occurred on the touch sensor; A first receiver is connected to the receiving electrodes to receive the first sensing signal; as well as A second receiver is connected to the first driving electrode to receive the second sensing signal. The second receiver includes a second current amplifier, which includes a first input terminal and a second input terminal. The second sensing signal is applied from the first driving electrode to the first input terminal of the second current amplifier, and the third sensing signal is applied from the second driving electrode, which is not to which the driving signal is applied, to the second input terminal of the second current amplifier.

2. The touch sensor controller as claimed in claim 1, further comprising: An analog-to-digital converter, configured to generate the touch data and the display noise data by performing analog-to-digital conversion on the outputs of the first receiver and the second receiver, respectively.

3. The touch sensor controller as described in claim 2, wherein: Each of the first receivers includes a first current amplifier, and the first current amplifier includes a first input terminal and a second input terminal. The first sensing signal is received at the first input terminal of the first current amplifier, and The third sensing signal is received at the second input terminal of the first current amplifier from the second driving electrode among the driving electrodes that is not subject to the driving signal.

4. The touch sensor controller as described in claim 2, wherein, Each of the first receivers further includes: A first filter, configured to filter the frequency of the output signal of a first current amplifier based on a first frequency; and A first gain amplifier is configured to amplify the output signal of the first filter.

5. The touch sensor controller as claimed in claim 1, wherein, The second receiver also includes: A second filter, configured to filter the frequency of the output signal of the second current amplifier based on a second frequency; and A second gain amplifier is configured to amplify the output signal of the second filter.

6. The touch sensor controller as claimed in claim 1, wherein: The first driving electrode includes at least one driving electrode channel spaced apart from at least one driving electrode to which the driving signal is applied, and The first driving electrode changes as driving signals are sequentially applied to the driving electrode.

7. The touch sensor controller of claim 6, further comprising a switching circuit configured to select another driving electrode from the driving electrodes to which the driving signal has not been applied as the first driving electrode as the driving signal is sequentially applied to the driving electrodes.

8. The touch sensor controller as claimed in claim 1, wherein, The touch processor is further configured to generate compensated touch data by removing the display noise data from the touch data, and to determine whether the touch input has occurred based on the compensated touch data.

9. The touch sensor controller as claimed in claim 1, wherein, The touch processor is also configured to discard the touch data when the display noise data is equal to or greater than a predetermined value.

10. A method of operating a touch sensor controller for driving a touch sensor, the touch sensor being stacked on a display panel and including driving electrodes and receiving electrodes intersecting the driving electrodes, the method comprising: A driving signal is applied to at least one of the driving electrodes; Touch sensing is performed by a first receiver disposed in the touch sensor controller; as well as Display noise sensing is simultaneously performed by at least one second receiver disposed in the touch sensor controller as the touch sensing is performed. in: Each of the first receivers receives a first sensing signal from the receiving electrode, including a touch signal generated based on the driving signal. The at least one second receiver receives a second sensing signal, including display noise, from the first driving electrode among the driving electrodes that is not subject to the driving signal. The second receiver includes a second current amplifier, which includes a first input terminal and a second input terminal. The second sensing signal is applied from the first driving electrode to the first input terminal of the second current amplifier, and a third sensing signal is applied from the second driving electrode, which is not to which the driving signal is applied, to the second input terminal of the second current amplifier.

11. The operating method as described in claim 10, wherein, The execution of the touch sensing includes: The first sensing signal is received by each of the first receivers; A touch sensing signal is generated by processing the first sensing signal; and A compensated touch sensing signal is generated by removing the display noise reference signal generated by the display noise sensing from the touch sensing signal.

12. The operating method as described in claim 10, wherein, The display noise sensing and the touch sensing are performed during the display period when the image is displayed on the display panel.

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