Display device having touch sensor

Abstract

A display device having a touch sensor of the present disclosure includes: a display panel including a plurality of touch electrodes; a touch sensing circuit configured to apply a touch driving signal to the touch electrode and amplify a charge flowing from the touch electrode based on an amplifier reset signal to generate an amplifier output voltage; and an amplifier output control circuit configured to adjust at least one of a trigger time of the amplifier reset signal and a voltage amplitude of the touch driving signal to differentially control a level of the amplifier output voltage according to a position of the touch electrode.

Description

[0001] This application is a divisional application of the parent application with the filing date of September 1, 2021, the application number of 202111020381.6, and the title of "Display device having touch sensor and driving method thereof".

[0002] This application claims the benefit of Korean Patent Application No. 10-2020-0186537, filed on December 29, 2020, which is incorporated by reference herein as if fully set forth in its entirety. TECHNICAL FIELD

[0003] The present disclosure relates to a display device having a touch sensor and a driving method thereof. BACKGROUND

[0004] Display devices having a touch sensor capable of sensing a touch input are well known. In a display device having a touch sensor, a parasitic capacitance and a load resistance generated in a touch electrode and a touch line vary depending on a distance between a touch sensing circuit and the touch electrode. Accordingly, as the distance between the touch sensing circuit and the touch electrode increases, an RC value increases, resulting in a decrease in touch sensitivity.

[0005] When a touch gain is determined based on a first position having the highest touch sensitivity, the touch sensitivity at a second position relatively far from the touch sensing circuit can deteriorate. On the other hand, when a touch gain is determined based on a second position having low touch sensitivity, a touch sensing value at a first position relatively close to the touch sensing circuit is saturated, and thus the touch sensitivity can deteriorate.

[0006] It is desirable that the touch sensitivity deviation of the entire touch panel is small. Since the touch sensitivity deviation is proportional to the size of the touch panel, it is necessary to improve the sensitivity deviation at each touch electrode position in the case of a large touch panel. SUMMARY

[0007] Accordingly, the present disclosure provides a display device having a touch sensor and a driving method thereof to improve touch performance by improving the sensitivity deviation at the touch electrode position.

[0008] To achieve these and other advantages, and according to the purposes of the invention, as specifically embodied and generally described herein, a display device having a touch sensor includes: a display panel including a plurality of touch electrodes; a touch sensing circuit configured to apply a touch drive signal to the touch electrodes and amplify charge flowing into the touch electrodes based on an amplifier reset signal to generate an amplifier output voltage; and an amplifier output control circuit configured to adjust at least one of a toggle timing of the amplifier reset signal and a voltage amplitude of the touch drive signal to differentially control the level of the amplifier output voltage according to the position of the touch electrodes.

[0009] In another aspect of the invention, a method for driving a display device having a touch sensor includes: applying a touch drive signal to a touch electrode of a display panel, and amplifying a charge flowing into the touch electrode based on an amplifier reset signal to generate an amplifier output voltage; and adjusting at least one of the trigger time of the amplifier reset signal and the voltage amplitude of the touch drive signal to differentially control the level of the amplifier output voltage according to the position of the touch electrode.

[0010] In another aspect of the invention, a display device having a touch sensor includes: a display panel including a plurality of touch electrodes; a touch driving circuit including a readout IC, each of the readout ICs including a touch sensing circuit and an amplifier output control circuit, wherein the touch sensing circuit is configured to apply a touch driving signal to the touch electrodes and amplify the charge flowing out of the touch electrodes based on an amplifier reset signal to generate an amplifier output voltage, and the amplifier output control circuit is configured to adjust at least one of the trigger time of the amplifier reset signal and the voltage amplitude of the touch driving signal to differentially control the level of the amplifier output voltage according to the position of the touch electrodes.

[0011] A display device with a touch sensor according to embodiments of the present disclosure can improve the sensitivity deviation at the touch electrode location to enhance touch performance.

[0012] Furthermore, the display device with a touch sensor according to embodiments of the present disclosure can improve the sensitivity deviation between sensing modes to enhance touch performance. Attached Figure Description

[0013] This invention includes accompanying drawings, which are incorporated in and constitute a part of this application, to provide a further understanding of the invention. The drawings illustrate embodiments of the invention and, together with the description, serve to explain the principles of the invention. In the drawings:

[0014] Figure 1and Figure 2 This is a diagram illustrating a display device with a touch sensor according to an embodiment of the present disclosure;

[0015] Figure 3 This is a diagram illustrating the configuration of the source and readout IC that integrates data driving circuitry and touch driving circuitry according to this disclosure;

[0016] Figure 4 This is a diagram showing the touch sensing circuitry included in the source and readout IC;

[0017] Figure 5 This is a diagram illustrating a concept for a technique used to improve sensitivity deviations at touch electrode locations;

[0018] Figure 6 and Figure 7 This is a diagram illustrating an example of differentially adjusting the trigger time of the amplifier reset signal applied to the touch sensing circuit based on the position of the touch electrode;

[0019] Figure 8 and Figure 9 This is a diagram illustrating a specific method for adjusting the trigger time of the amplifier reset signal;

[0020] Figure 10 and Figure 11 This is a diagram illustrating an example of differentially adjusting the voltage amplitude of a touch drive signal applied to a touch sensing circuit;

[0021] Figure 12 This is a diagram illustrating a multiplexer circuit for selectively connecting touch electrodes to a touch sensing circuit;

[0022] Figure 13 This is a diagram illustrating an example configuration of a circuit for differentially adjusting the trigger time of an amplifier reset signal based on the position of the touch electrode.

[0023] Figure 14 and Figure 15 This is a diagram illustrating an example configuration of a circuit for differentially adjusting the voltage amplitude of a touch drive signal based on the position of the touch electrode.

[0024] Figure 16 and Figure 17 This is a diagram illustrating an example of a hybrid configuration for differentially adjusting the trigger time of the amplifier reset signal and the voltage amplitude of the touch drive signal based on the position of the touch electrode;

[0025] Figure 18 This is a diagram illustrating an example of differential adjustment of the trigger time of the amplifier reset signal in finger sensing mode and pen sensing mode;

[0026] Figure 19 This is a diagram illustrating an example of differential adjustment of the trigger time of the amplifier reset signal in self-inductance mode and mutual inductance mode. Detailed Implementation

[0027] Reference will now be made in detail to preferred embodiments of the present disclosure, examples of which are illustrated in the accompanying drawings. Where possible, the same reference numerals will be used throughout the drawings to refer to the same or similar parts. In the following description, detailed descriptions of known functions and configurations incorporated herein will be omitted where such descriptions may obscure the subject matter of the disclosure.

[0028] Figure 1 and Figure 2 This is a diagram illustrating a display device with a touch sensor according to an embodiment of the present disclosure.

[0029] refer to Figure 1 and Figure 2 The display device with a touch sensor according to this disclosure can be implemented based on a flat panel display such as a liquid crystal display (LCD), a field emission display (FED), a plasma display panel (PDP), an organic light-emitting display (OLED), or an electrophoretic display (EPD). Although the display device is implemented as an LCD in the following embodiments, the display device of this disclosure is not limited to LCD.

[0030] The display device with touch sensor disclosed herein may include a display panel 10, a data driving circuit 12, a gate driving circuit 14, a timing controller 16, a touch driving circuit 18, a host system 19, and a power supply circuit 20.

[0031] The display panel 10 includes a liquid crystal layer formed between two substrates. The pixel array of the display panel 10 includes pixels PXL formed in pixel regions defined by data lines D1 to Dm (m is a positive integer) and gate lines G1 to Gn (n is a positive integer). Each pixel PXL may include a thin-film transistor (TFT), a pixel electrode charged with a data voltage, a storage capacitor Cst for maintaining the voltage of the liquid crystal cell, and a common electrode COM formed at each intersection of the data lines D1 to Dm and the gate lines G1 to Gn.

[0032] The common electrode COM of the pixel PXL is divided into segments, and the touch electrode TS is implemented as a common electrode segment. A single common electrode segment is connected to multiple pixels PXL to form a single touch electrode TS. Multiple touch electrodes arranged in a row can form a touch block line. Each touch sensor may include a pixel defined by gate lines and data lines. Each touch block line overlaps with multiple pixel lines, and a touch block line is wider than a pixel line. Here, a pixel line consists of pixels PXL arranged in a row.

[0033] A black matrix and a color filter can be formed on the upper substrate of the display panel 10. The lower substrate of the display panel 10 can be implemented as a TFT upper color filter (COT) structure. In this case, the black matrix and the color filter can be formed on the lower substrate of the display panel 10. A common electrode providing a common voltage can be formed on either the upper or lower substrate of the display panel 10. A polarizing plate can be attached to the upper and lower substrates of the display panel 10, and an alignment film for setting the pretilt angle of the liquid crystal is formed on the inner side of the upper and lower substrates in contact with the liquid crystal. A column spacer for maintaining the cell gap of the liquid crystal cells is formed between the upper and lower substrates of the display panel 10.

[0034] The backlight unit can be disposed on the back of the display panel 10. The backlight unit is implemented as an edge-type or direct-lit backlight unit and radiates light onto the display panel 10. The display panel 10 can be implemented as any known liquid crystal mode, such as twisted nematic (TN) mode, vertical alignment (VA) mode, in-plane switching (IPS) mode, and edge field switching (FFS) mode.

[0035] The timing controller 16 receives timing signals input from the host system 19, such as the vertical synchronization signal Vsync, the horizontal synchronization signal Hsync, the data enable signal DE, and the master clock signal MCLK, and controls the operating timing of the data drive circuit 12, the gate drive circuit 14, and the touch drive circuit 18. Scan timing control signals may include the gate start pulse signal GSP, the gate shift clock signal GSC, and the gate output enable signal GOE. Data timing control signals may include the source sampling clock signal SSC, the polarity control signal POL, and the source output enable signal SOE. The timing controller 16 may include... Figures 12 to 15 The microcontroller unit (MCU) shown.

[0036] The timing controller 16 can be based on the touch synchronization signal (see reference). Figure 16 , Figure 18 and Figure 19 The TSYNC signal divides the driving period of the display panel into a display driving period Pd and a touch sensor driving period Pt. The data driving circuit 12, gate driving circuit 14, and touch driving circuit 18 are synchronized in response to the touch synchronization signal TSYNC. The first logic level of the touch synchronization signal TSYNC defines the display driving period Pd, and its second logic level defines the touch sensor driving period Pt. The first logic level can be high, and the second logic level can be low, or vice versa.

[0037] Under the control of the timing controller 16, the data driving circuit 12 and the gate driving circuit 14 write the input image data RGB into the pixel PXL of the display panel 10.

[0038] The data driving circuit 12 includes multiple source driver integrated circuits (ICs) SICs that convert the digital image data RGB input from the timing controller 16 into analog positive / negative gamma compensation voltages to generate data voltages according to the scan timing control signal, and output the data voltages during the display driving period Pd. The data voltages output from the data driving circuit 12 are supplied to data lines D1 to Dm.

[0039] Data driving circuit 12 applies an AC signal with the same phase and amplitude as the touch driving signal Tdrv applied to the touch electrode TS during the touch sensor driving period Pt to data lines D1 to Dm (see...). Figure 3 The parasitic capacitance between the touch electrode TS and the data lines D1 to Dm is minimized (Sdrv) to reduce its impact on the touch electrode TS. This is because when the voltage across the parasitic capacitor changes simultaneously and the voltage difference is small, the charge stored in the parasitic capacitor decreases. When the impact of parasitic capacitance on the touch electrode TS is reduced, display noise mixed in with the touch sensing results can be minimized, and distortion of the amplifier output voltage, which serves as the touch sensing signal, can be prevented.

[0040] The gate drive circuit 14 generates a gate pulse signal synchronized with the data voltage by referencing the scan timing control signal, and outputs the gate pulse signal to the gate lines G1 to Gn during the display drive period Pd to select one display line of the display panel 10 that is written with the data voltage.

[0041] The gate drive circuit 14 generates an AC signal with the same phase and amplitude as the touch drive signal Tdrv applied to the touch electrode TS during the touch sensor drive period Pt, and applies the AC signal to the gate lines G1 to Gn to minimize the parasitic capacitance between the touch electrode TS and the gate lines G1 to Gn, and reduce the influence of the parasitic capacitance on the touch electrode TS. When the parasitic capacitance between the touch electrode TS and the gate lines G1 to Gn is minimized, the display noise mixed in the touch sensing result can be minimized, and distortion of the amplifier output voltage, which is the touch sensing signal, can be prevented.

[0042] The gate drive circuit 14 can be configured as a gate driver IC or can be formed directly on the lower glass substrate of the display panel 10 as an in-panel gate driver (GIP) structure.

[0043] The touch driving circuit 18 includes a readout IC RIC. During the touch sensor driving period Pt, the touch driving circuit 18 drives and senses touch electrodes TS included in the pixel array of the display panel 10. The touch electrodes TS can constitute a capacitive sensor for sensing touch input. The capacitive sensor can be implemented based on self-capacitance or mutual capacitance. Self-capacitance and mutual capacitance can be formed along a single layer of wire formed in one direction, or between two orthogonal wires.

[0044] Each readout IC RIC may include a touch sensing circuit that operates during the touch sensor driving period Pt. Figure 3 The touch sensing circuit includes the SU (Su) and amplifier output control circuit. Figure 3 The SU in the middle applies a touch drive signal to the touch electrode TS. Figure 3 (Tdrv in the middle), and based on the amplifier reset signal (reference) Figure 4 The RST signal amplifies the charge flowing from the touch electrode TS to generate the amplifier output voltage. The amplifier output control circuit can differentially control the level of the amplifier output voltage according to the position of the touch electrode TS by adjusting at least one of the trigger time of the amplifier reset signal RST and the voltage amplitude of the touch drive signal Tdrv, thereby improving the sensitivity deviation at the touch electrode position and enhancing touch performance.

[0045] like Figure 2 As shown, the readout IC RIC and the source driver IC SIC can be integrated into a single chip to implement the source and readout IC SRIC. The source and readout IC SRIC can be mounted on a source-on-film chip (SCOF).

[0046] The host system 19 can transmit timing signals Vsync, Hsync, DE and MCLK together with digital image data RGB to the timing controller 16 and execute the application associated with touch sensing data TDATA(XY) input from the touch driver circuit 18.

[0047] The host system 19 refers to the system body of an electronic device to which the display device of this disclosure can be applied. The host system 19 can be any of a telephone system, a television (TV) system, a set-top box, a navigation system, a DVD player, a Blu-ray player, a personal computer (PC), and a home theater system. The host system 19 receives touch input data TDATA(XY) from the touch sensing IC TIC and executes applications associated with the touch input.

[0048] The power supply circuit 20 generates the driving power required for the operation of the touch driving circuit 18. The power supply circuit 20 can be implemented as an integrated circuit, such as... Figure 12 and Figure 14The "Touch Power IC (TPIC)" is mentioned. Depending on the requirements, the power supply circuit 20 may include an amplifier output control circuit (including...). Figure 14 (Tdrv regulator in the middle).

[0049] Figure 3 This is a diagram illustrating the configuration of the source and readout IC that integrates the data driving circuit and the touch driving circuit according to this disclosure. Figure 4 This is a diagram showing the touch sensing circuitry included in the source and readout IC.

[0050] refer to Figure 3 and Figure 4 The source and readout IC SRIC includes a source driver IC SIC that drives the data lines D1 to D5 of the display panel 10 and a readout IC RIC that drives the touch lines SL connected to the touch electrodes TS of the display panel 10. In the source and readout IC SRIC, the source driver IC SIC and the readout IC RIC can be "circuits" that are functionally separate from each other.

[0051] The source driver IC (SIC) includes a digital-to-analog converter that generates the data voltage Vdata and an output buffer (BUF) that stabilizes the data voltage Vdata. During the display driving period, the source driver IC (SIC) outputs the data voltage Vdata to data lines D1 through D5, and during the touch sensor driving period, it outputs an AC signal (refer to Sdrv) to reduce the impact of parasitic capacitance on data lines D1 through D5.

[0052] The readout IC RIC may include a multiplexer MUX, a touch sensing circuit SU, and a common voltage generator (not shown). The common voltage generator may be included in... Figure 1 In the power supply circuit 20 shown, a common voltage generator produces the common voltage required for the display to operate. Depending on the type of display device, the common voltage can be various display voltages. For example, the common voltage can be the voltage applied to the common electrode in a liquid crystal display, or it can be the voltage applied to the cathode in an organic light-emitting display device.

[0053] Under the control of timing controller 16, each multiplexer MUX selectively connects the touch sensing circuit SU and the common voltage generator to the touch electrodes. When the touchscreen has a resolution of M×N (M and N are positive integers equal to or greater than 2), the touch electrodes TS can be segmented into M×N touch electrode segments, and M multiplexers can be configured. Each multiplexer MUX is connected to N touch electrodes TS via N touch lines SL, and the N touch lines SL are sequentially connected to a single touch sensing circuit SU.

[0054] The touch sensing circuit SU is connected to the touch line SL via a multiplexer MUX to apply the touch drive signal Tdrv to the touch electrode TS, sense the charge flowing out of the touch electrode TS, and generate touch sensing data TDATA.

[0055] like Figure 4 As shown, the touch sensing circuit SU includes a preamplifier that amplifies the voltage of the touch capacitor CS based on the amplifier reset signal RST, an integrator that accumulates the amplifier output voltage of the preamplifier, and an analog-to-digital converter (ADC) that converts the output voltage of the integrator into digital data. The digital data generated by the ADC is transmitted to the host system as touch sensing data TDATA. When the touchscreen has an M×N resolution, M touch sensing circuits SU are required.

[0056] The touch capacitor CS has self-capacitance and mutual capacitance, and is formed in the touch electrode. A preamplifier is connected to the touch electrode via the touch line SL and receives the charge stored in the touch capacitor CS. A load resistor element LR and a parasitic capacitance element CP may be present on the touch line SL.

[0057] The preamplifier includes an amplifier AMP, a feedback capacitor CFB, and a reset switch SW. The inverting input (-) of the amplifier AMP is connected to the touch line SL, and the non-inverting input (+) of the amplifier AMP is supplied with a touch drive signal Tdrv. The output of the amplifier AMP is connected to an integrator. The feedback capacitor CFB is connected between the inverting input (-) of the amplifier AMP and its output. The reset switch is also connected between the inverting input (-) of the amplifier AMP and its output. The reset switch SW is activated synchronously with the trigger time of the amplifier reset signal RST. The preamplifier stores the charge flowing from the touch electrode in the feedback capacitor CFB until the reset switch SW is activated, and supplies the stored voltage as the amplifier output voltage to the integrator. This amplifier output voltage varies based on the RC value of the touch line SL according to the touch electrode position, which may cause sensitivity deviations at the touch electrode position. Therefore, improvements are proposed such as... Figures 5 to 19 The method for measuring sensitivity deviation at the indicated location.

[0058] Figure 5 This is a diagram illustrating a concept for a technique used to improve sensitivity deviations at touch electrode locations. Figure 6 and Figure 7 This is a diagram illustrating an example of differentially adjusting the trigger time of the amplifier reset signal applied to the touch sensing circuit based on the position of the touch electrode. Figure 8 and Figure 9 This is a diagram illustrating a specific method for adjusting the trigger time of the amplifier reset signal. Figure 10 and Figure 11This is a diagram illustrating an example of differentially adjusting the voltage amplitude of a touch drive signal applied to a touch sensing circuit.

[0059] refer to Figure 5 The amplifier output control circuit differentially controls the level of the amplifier output voltage based on the position of the touch electrode to improve sensitivity deviation at the touch electrode position. To this end, the amplifier output control circuit can adjust at least one of the trigger time of the amplifier reset signal RST and the voltage amplitude of the touch drive signal Tdrv. In other words, the amplifier output control circuit can include at least one of an RST regulator that differentially adjusts the trigger time of the amplifier reset signal RST based on the position of the touch electrode and a Tdrv regulator that differentially adjusts the voltage amplitude of the touch drive signal Tdrv based on the position of the touch electrode.

[0060] The RST regulator can differentially adjust the trigger time of the amplifier reset signal based on a predetermined on start timing and on duty time of the amplifier reset signal according to the position of the touch electrode.

[0061] The RST regulator can adjust the trigger time of the amplifier reset signal RST to the first start time Ta for the touch electrode at the first position AR1, adjust the trigger time of the amplifier reset signal RST to the second start time Tb before the first start time Ta for the touch electrode at the second position AR2, and adjust the trigger time of the amplifier reset signal RST to the third start time Tc before the second start time Tb for the touch electrode at the third position AR3. Here, the first position AR1 is farther from the touch sensing circuit SU than the second position AR2, and the second position AR2 is farther from the touch sensing circuit SU than the third position AR3.

[0062] refer to Figure 6 and Figure 7 Regarding the touch electrode at the first position AR1, the preamplifier stores the charge flowing from the touch electrode at the first position AR1 in the feedback capacitor CFB from the rise time of the touch drive signal Tdrv to the first start time Ta of the amplifier reset signal RST, and supplies the stored voltage to the integrator as the first amplifier output voltage VA. The integrator then accumulates the first amplifier output voltage VA multiple times (e.g., 3 times) to generate the first integrator output voltage.

[0063] refer to Figure 6 and Figure 7Regarding the touch electrode at the second position AR2, the preamplifier stores the charge flowing from the touch electrode at the second position AR2 in the feedback capacitor CFB from the rise time of the touch drive signal Tdrv to the second start time Tb of the amplifier reset signal RST, and supplies the stored voltage as the second amplifier output voltage VB to the integrator. The integrator then accumulates the second amplifier output voltage VB multiple times (e.g., 3 times) to generate the second integrator output voltage.

[0064] exist Figure 6 and Figure 7 In this process, the voltage amplitude of the touch drive signal Tdrv applied to all touch electrodes is fixed as the difference between VTH and VTL, regardless of the electrode position.

[0065] Since the second start time Tb is before the first start time Ta, the level of the second amplifier output voltage VB is "ΔV" lower than the level of the first amplifier output voltage VA. Therefore, the level of the second integrator output voltage is "ΔAV" lower than the level of the first integrator output voltage VA.

[0066] In this way, the level of the amplifier output voltage can be differentially controlled based on the position of the touch electrode according to the trigger time of the amplifier reset signal RST. The level of the amplifier output voltage can be controlled so that it is higher at the first position AR1 than at the second position AR2, and higher at the third position AR3 than at the second position AR2. Therefore, the level of the amplifier output voltage increases as the position of the touch electrode moves further away from the touch sensing circuit SU, thus effectively reducing the sensitivity deviation at the touch electrode position.

[0067] To adjust the trigger time of the amplifier reset signal RST to the first start time Ta, the second start time Tb, and the third start time Tc, the RST regulator can generate three amplifier reset signals RST with the same operating time but different phases, such as... Figure 8 As shown.

[0068] Furthermore, in order to adjust the trigger time of the amplifier reset signal RST to the first start time Ta, the second start time Tb, and the third start time Tc, the RST regulator can generate three amplifier reset signals RST with different operating times, such as... Figure 9 As shown. Therefore, the amplifier reset signal RST with a first start time Ta can have a first operating time, the amplifier reset signal RST with a second start time Tb can have a second operating time, and the amplifier reset signal RST with a third start time Tc can have a third operating time. In this case, the first operating time is shorter than the second operating time, and the second operating time is shorter than the third operating time. That is, refer to... Figure 9The three amplifier reset signals RST, which have different operating times, can have the same fall time and different rise times.

[0069] like Figure 5 As shown, the Tdrv regulator can adjust the voltage amplitude of the touch drive signal Tdrv to a first value Da for the touch electrode at the first position AR1, adjust the voltage amplitude of the touch drive signal Tdrv to a second value Db for the touch electrode at the second position AR2, and adjust the voltage amplitude of the touch drive signal Tdrv to a third value Dc for the touch electrode at the third position AR3. Here, the first value Da is greater than the second value Db, and the second value Db is greater than the third value Dc.

[0070] refer to Figure 10 and Figure 11 Regarding the touch electrode at the second position AR2, the preamplifier stores the charge flowing from the touch electrode at the first position AR1 in the feedback capacitor CFB from the rise time of the touch drive signal Tdrv with an amplitude of a first value Da to the start time of the amplifier reset signal RST, and supplies the stored voltage as the first amplifier output voltage VA to the integrator. The integrator then accumulates the first amplifier output voltage VA multiple times (e.g., 3 times) to generate the first integrator output voltage.

[0071] refer to Figure 10 and Figure 11 Regarding the touch electrode at the second position AR2, the preamplifier stores the charge flowing from the touch electrode at the second position AR2 in the feedback capacitor CFB from the rise time of the touch drive signal Tdrv with an amplitude of the second value Db to the start time Tb of the amplifier reset signal RST, and supplies the stored voltage as the second amplifier output voltage VB to the integrator. The integrator then accumulates the second amplifier output voltage VB multiple times (e.g., 3 times) to generate the second integrator output voltage.

[0072] exist Figure 10 and Figure 11 In this circuit, the start time of the amplifier reset signal RST is fixed and is independent of the position of the touch electrode.

[0073] Because the amplitude of the second value Db is smaller than the amplitude of the first value Da, the level of the second amplifier output voltage VB is lower than the level of the first amplifier output voltage VA. Therefore, the level of the second integrator output voltage VB is "ΔAV" lower than the level of the first integrator output voltage VA.

[0074] In this way, the amplifier output voltage level can be differentially controlled based on the touch electrode position according to the voltage amplitude of the touch drive signal Tdrv. The amplifier output voltage level can be controlled so that it is higher at the first position AR1 than at the second position AR2, and higher at the third position AR3 than at the second position AR2. Therefore, the amplifier output voltage level increases as the touch electrode is further away from the touch sensing circuit SU, thus effectively reducing the sensitivity deviation at the touch electrode position.

[0075] Figure 12 This is a diagram illustrating a multiplexer circuit for selectively connecting touch electrodes to a touch sensing circuit. Figure 13 This is a diagram illustrating an example configuration of a circuit for differentially adjusting the trigger time of an amplifier reset signal based on the position of the touch electrode.

[0076] refer to Figure 12 and Figure 13 The RST regulator can be included in the digital circuitry block of the source and readout IC SRIC along with the MUX counter and set register. The RST regulator, MUX counter, and set register are controlled by the MCU. The MCU can be mounted on the source printed circuit board (SPCB) along with the TPIC.

[0077] The MUX counter generates MUX count information indicating the connection order of the touch electrode TS and the touch sensing circuit SU through the multiplexer MUX. The MUX count information is generated with different values ​​depending on the position of the touch electrode TS. Based on the position of the touch electrode TS, different start times and operating times of the amplifier reset signal RST are preset in the setting register. The information related to the amplifier reset signal RST in the setting register can be corrected via the MCU.

[0078] The RST regulator reads the amplifier reset signal RST corresponding to the position of the touch electrode TS from the setting register based on the MUX count information. Therefore, the trigger time of the amplifier reset signal RST can be differentially adjusted according to the position of the touch electrode.

[0079] Figure 14 and Figure 15 This is a diagram illustrating an example configuration of a circuit for differentially adjusting the voltage amplitude of a touch drive signal based on the position of the touch electrode.

[0080] like Figure 14 As shown, the Tdrv regulator can be included in the TPIC, or as... Figure 15 As shown, the Tdrv regulator can be included in the analog circuit block of the source and readout IC SRIC.

[0081] exist Figure 14 andFigure 15 In, such as Figure 13 The MUX counter shown is installed in the digital circuitry block of the source and readout IC SRIC. The MUX counter generates MUX count information indicating the order of connection between the touch electrode TS and the touch sensing circuit SU via the multiplexer MUX. The MUX count information is generated as different values ​​depending on the position of the touch electrode TS.

[0082] The Tdrv regulator detects the position of the touch electrode TS based on the MUX count information and adjusts the voltage amplitude of the touch drive signal Tdrv accordingly. The Tdrv regulator supplies the touch drive signal Tdrv, with a voltage amplitude adjusted according to the position of the touch electrode TS, to the touch sensing circuit SU. The touch drive signal Tdrv is applied to the touch electrode TS through the preamplifier of the touch sensing circuit SU. Therefore, the voltage amplitude of the touch drive signal Tdrv can be differentially adjusted according to the position of the touch electrode.

[0083] Figure 16 and Figure 17 This is a diagram illustrating an example of a hybrid configuration for differentially adjusting the trigger time of the amplifier reset signal and the voltage amplitude of the touch drive signal based on the position of the touch electrode.

[0084] refer to Figure 12 , Figure 16 and Figure 17 The touch electrode connected through the first multiplexer MUX1 is furthest from the touch sensing circuit SU, while the touch electrode connected through the nth multiplexer MUXn is closest to the touch sensing circuit SU.

[0085] During the display driving period Pd, the amplifier output control circuit differentially adjusts the trigger time of the amplifier reset signal RST and the voltage amplitude LFD of the touch drive signal Tdrv according to the position of the touch electrode. Then, during the touch sensor driving period Pt, the touch sensing circuit SU drives and senses the touch electrode based on the adjusted factors.

[0086] The amplifier output control circuit can adjust the voltage amplitude of the touch drive signal Tdrv to the same value Da for the touch electrodes connected via the first multiplexer MUX1 and the second multiplexer MUX2. However, the amplifier output control circuit can adjust the trigger time of the first amplifier reset signal RST to Ta for the first touch electrode connected via the first multiplexer MUX1, and adjust the trigger time of the second amplifier reset signal RST to Tb for the second touch electrode connected via the second multiplexer MUX2. The amplifier output control circuit can control the operating time of the first amplifier reset signal RST to be shorter than the operating time of the second amplifier reset signal RST, so that the amplifier output voltage of the first touch electrode is higher than the amplifier output voltage of the second touch electrode.

[0087] The amplifier output control circuit can adjust the voltage amplitude of the touch drive signal Tdrv to the same value Db for the touch electrodes connected via the third multiplexer MUX3 and the fourth multiplexer MUX4. Here, Db is less than Da. However, the amplifier output control circuit can adjust the trigger time of the third amplifier reset signal RST to Ta' for the third touch electrode connected via the third multiplexer MUX3, and adjust the trigger time of the fourth amplifier reset signal RST to Tb' for the fourth touch electrode connected via the fourth multiplexer MUX4. The amplifier output control circuit can control the operating time of the third amplifier reset signal RST to be shorter than that of the fourth amplifier reset signal RST, so that the amplifier output voltage of the third touch electrode is higher than that of the fourth touch electrode.

[0088] The amplifier output control circuit can adjust the voltage amplitude of the touch drive signal Tdrv to the same value Dc for the touch electrodes connected through the (n-1)th multiplexer MUXn-1 and the nth multiplexer MUXn. Here, Dc is less than Db. However, the amplifier output control circuit can adjust the trigger time of the (n-1)th amplifier reset signal RST to Ta” for the (n-1)th touch electrode connected through the (n-1)th multiplexer MUXn-1, and adjust the trigger time of the nth amplifier reset signal RST to Tb” for the nth touch electrode connected through the nth multiplexer MUXn. The amplifier output control circuit can control the operating time of the (n-1)th amplifier reset signal RST to be shorter than the operating time of the nth amplifier reset signal RST, so that the amplifier output voltage of the (n-1)th touch electrode is higher than the amplifier output voltage of the nth touch electrode.

[0089] Figure 18 This diagram illustrates an example of differential adjustment of the amplifier reset signal trigger time in finger sensing mode and pen sensing mode. Figure 19This is a diagram illustrating an example of differential adjustment of the trigger time of the amplifier reset signal in self-inductance mode and mutual inductance mode.

[0090] refer to Figure 18 During the touch sensor driving period Pt, the touch sensing circuit can implement both finger sensing mode and pen sensing mode. In finger sensing mode, the touch sensing circuit generates an amplifier output voltage based on finger touch input, and in pen sensing mode, it generates an amplifier output voltage based on pen touch input. For the touch electrode at the same location, the touch sensitivity may differ between finger sensing mode and pen sensing mode.

[0091] For touch electrodes at the same location, the amplifier output circuit can adjust the trigger time of the amplifier reset signal RST to the first start time in pen sensing mode, and can adjust the trigger time of the amplifier reset signal RST to the second start time before the first start time in finger sensing mode, so as to improve the touch sensitivity deviation between sensing modes.

[0092] refer to Figure 19 During the touch sensor driving period Pt, the touch sensing circuit can implement both self-inductance mode and mutual inductance mode. In self-inductance mode, the touch sensing circuit generates an amplifier output voltage based on the self-capacitance according to the touch input, and in mutual inductance mode, it generates an amplifier output voltage based on the mutual capacitance according to the touch input. For the touch electrode at the same location, the touch sensitivity may differ between self-inductance mode and mutual inductance mode.

[0093] For touch electrodes at the same location, the amplifier output circuit can adjust the trigger time of the amplifier reset signal RST to the first start time in self-inductance mode, and adjust the trigger time of the amplifier reset signal RST to the second start time before the first start time in mutual inductance mode, so as to improve the touch sensitivity deviation between sensing modes.

[0094] It will be apparent to those skilled in the art that various modifications and alterations can be made to this disclosure without departing from its spirit or scope. Therefore, this disclosure is intended to cover any modifications and alterations to this disclosure that fall within the scope of the appended claims and their equivalents.

[0095] A display device with a touch sensor according to embodiments of the present disclosure can improve the sensitivity deviation at the touch electrode location to enhance touch performance.

[0096] Furthermore, the display device with a touch sensor according to embodiments of the present disclosure can improve the sensitivity deviation between sensing modes to enhance touch performance.

Claims

1. A display device having a touch sensor, comprising: The display panel includes a plurality of touch electrodes; as well as A readout integrated circuit, wherein the readout integrated circuit is configured to: A touch drive signal is applied to the plurality of touch electrodes, and the charge from the plurality of touch electrodes is amplified according to an amplifier reset signal to generate an amplifier output voltage. The trigger time of the amplifier reset signal is differentially adjusted based on the position of the plurality of touch electrodes to control the level of the amplifier output voltage.

2. The display device according to claim 1, wherein, The readout integrated circuit is further configured to: Based on the positions of the plurality of touch electrodes, the start time and duty cycle of the amplifier reset signal are differentially adjusted.

3. The display device according to claim 1, wherein, The readout integrated circuit includes a touch sensing circuit and an amplifier output control circuit.

4. The display device according to claim 3, wherein, The amplifier output control circuit is configured as follows: For the first group of touch electrodes at the first position among the plurality of touch electrodes, the trigger time of the amplifier reset signal is adjusted to the first start time. For the second group of touch electrodes at the second position among the plurality of touch electrodes, the trigger time of the amplifier reset signal is adjusted to a second start time before the first start time, and The first position is farther from the touch sensing circuit than the second position.

5. The display device according to claim 4, wherein, The amplifier reset signal with the first start time and the amplifier reset signal with the second start time have the same duty cycle and different phases.

6. The display device according to claim 4, wherein, The amplifier reset signal having the first start time has a first duty cycle, and the amplifier reset signal having the second start time has a second duty cycle. The first duty cycle is smaller than the second duty cycle.

7. The display device according to claim 3, wherein, The amplifier output control circuit is further configured as follows: For the first group of touch electrodes at a first position among the plurality of touch electrodes, the voltage amplitude of the touch driving signal is adjusted to a first value. For the second group of touch electrodes at the second position among the plurality of touch electrodes, the voltage amplitude of the touch driving signal is adjusted to a second value that is less than the first value, and The first position is farther from the touch sensing circuit than the second position.

8. The display device according to claim 7, wherein, The amplifier output control circuit is further configured as follows: When touch sensing periods and display periods are arranged alternately multiple times in a frame, the voltage amplitude of the touch driving signal is adjusted to the first value or the second value during the display period.

9. The display device according to claim 3, wherein, The touch sensing circuit is configured as follows: In finger-sensing mode, the amplifier output voltage is generated based on finger touch input, and In pen-sensing mode, the amplifier output voltage is generated based on pen touch input.

10. The display device according to claim 9, wherein, The touch sensitivity in the finger sensing mode is different from the touch sensitivity in the pen sensing mode.

11. The display device according to claim 9, wherein, The amplifier output control circuit is configured as follows: In the pen sensing mode, the trigger time of the amplifier reset signal is adjusted to the first start time, and In the finger sensing mode, the trigger time of the amplifier reset signal is adjusted to a second start time prior to the first start time.

12. The display device according to claim 1, wherein, The readout integrated circuit includes multiple multiplexers, touch sensing circuitry, and a common voltage generator.

13. A display device having a touch sensor, comprising: The display panel includes a plurality of touch electrodes; A touch sensing circuit configured to apply a touch drive signal to the touch electrode and amplify the charge flowing out of the touch electrode based on an amplifier reset signal to generate an amplifier output voltage; as well as An amplifier output control circuit is configured to differentially adjust the trigger time of the amplifier reset signal based on the position of the touch electrode, or differentially adjust the voltage amplitude of the touch drive signal based on the position of the touch electrode, so as to differentially control the level of the amplifier output voltage based on the position of the touch electrode. The amplifier output control circuit is configured to differentially adjust the start time and duty cycle of the amplifier reset signal according to the position of the touch electrode.

14. The display device with a touch sensor according to claim 13, wherein, For the touch electrode at the first position, the amplifier output control circuit adjusts the trigger time of the amplifier reset signal to a first start time; and for the touch electrode at the second position, the amplifier output control circuit adjusts the trigger time of the amplifier reset signal to a second start time prior to the first start time. The first position is farther from the touch sensing circuit than the second position.

15. The display device with a touch sensor according to claim 14, wherein, The amplifier reset signal with the first start time and the amplifier reset signal with the second start time have the same duty cycle and different phases.

16. The display device with a touch sensor according to claim 14, wherein, The amplifier reset signal having the first start time has a first duty cycle, and the amplifier reset signal having the second start time has a second duty cycle. The first duty cycle is shorter than the second duty cycle.

17. The display device with a touch sensor according to claim 13, wherein, The amplifier output control circuit is configured to: for the touch electrode at the first position, adjust the voltage amplitude of the touch driving signal to a first value, and for the touch electrode at the second position, adjust the voltage amplitude of the touch driving signal to a second value less than the first value. The first position is farther from the touch sensing circuit than the second position.

18. The display device with a touch sensor according to claim 17, wherein, When touch sensing periods and display periods are arranged alternately multiple times in a frame, the amplifier output control circuit is configured to adjust the voltage amplitude of the touch driving signal to the first value or the second value during the display period.

19. The display device with a touch sensor according to claim 13, wherein, The touch sensing circuit is configured to generate the amplifier output voltage based on finger touch input in finger sensing mode, and to generate the amplifier output voltage based on pen touch input in pen sensing mode. For touch electrodes at the same location, the amplifier output control circuit is configured to adjust the trigger time of the amplifier reset signal to a first start time in the pen sensing mode, and to adjust the trigger time of the amplifier reset signal to a second start time prior to the first start time in the finger sensing mode.

20. The display device with a touch sensor according to claim 13, wherein, The touch sensing circuit is configured to generate the amplifier output voltage based on self-capacitance according to touch input in self-inductance mode, and to generate the amplifier output voltage based on mutual capacitance according to touch input in mutual inductance mode. For touch electrodes at the same location, the amplifier output circuit is configured to adjust the trigger time of the amplifier reset signal to a first start time in the self-inductance mode, and to adjust the trigger time of the amplifier reset signal to a second start time prior to the first start time in the mutual inductance mode.

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