Display device having a touch sensor and driving method thereof

Abstract

The display device with a touch sensor according to 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 electrodes and amplify the charge flowing in from 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 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 electrodes.

Description

[0001] This application claims the benefit of Korean Patent Application No. 10-2020-0186537, filed on Dec. 29, 2020, which is incorporated herein by reference in its entirety as if fully set forth herein. Technical Field

[0002] The present disclosure relates to a display device having a touch sensor and a driving method thereof. Background Art

[0003] A display device having a touch sensor capable of sensing a touch input is well known. In a display device having a touch sensor, parasitic capacitance and load resistance generated in touch electrodes and touch lines vary according to the distance between a touch sensing circuit and the touch electrodes. Therefore, as the distance between the touch sensing circuit and the touch electrodes increases, the RC value increases, resulting in a decrease in touch sensitivity.

[0004] When determining a touch gain based on a first position having the highest touch sensitivity, the touch sensitivity at a second position relatively far from the touch sensing circuit may deteriorate. On the other hand, when determining the touch gain based on a second position having a low touch sensitivity, the touch sensing value at a first position relatively close to the touch sensing circuit saturates, and thus the touch sensitivity may deteriorate.

[0005] 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 of the Invention

[0006] 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 touch electrode positions.

[0007] To achieve these and other advantages and in accordance with the purpose of the present invention, as embodied and broadly 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 driving signal to the touch electrodes and amplify charges flowing in from 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 trigger time (toggle timing) 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 the position of the touch electrode.

[0008] In another aspect of the present invention, a method for driving a display device having a touch sensor includes: applying a touch driving signal to a touch electrode of a display panel, and amplifying charges flowing in from the touch electrode based on an amplifier reset signal to generate an amplifier output voltage; and adjusting 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.

[0009] In yet another aspect of the present 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 charges flowing out from 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 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.

[0010] A display device having a touch sensor according to an embodiment of the present disclosure can improve sensitivity deviation at a touch electrode position to enhance touch performance.

[0011] In addition, a display device having a touch sensor according to an embodiment of the present disclosure can improve sensitivity deviation between sensing modes to enhance touch performance. BRIEF DESCRIPTION OF THE DRAWINGS

[0012] The present invention includes drawings to provide a further understanding of the present invention and is incorporated into and constitutes a part of this application. The drawings illustrate embodiments of the present invention and, together with the description, are used to explain the principles of the present invention. In the drawings:

[0013] Figure 1 and Figure 2 is a diagram showing a display device having a touch sensor according to an embodiment of the present disclosure;

[0014] Figure 3 is a diagram showing a configuration of a source and readout IC (source&readout IC) integrating a data driving circuit and a touch driving circuit according to the present disclosure;

[0015] Figure 4 is a diagram showing a touch sensing circuit included in the source and readout IC;

[0016] Figure 5 is a diagram showing a concept of a technique for improving sensitivity deviation at a touch electrode position;

[0017] Figure 6 and Figure 7 is a diagram showing an example of differentially adjusting the trigger time of an amplifier reset signal applied to a touch sensing circuit according to the position of a touch electrode;

[0018] Figure 8 and Figure 9 is a diagram showing a specific method for adjusting the trigger time of an amplifier reset signal;

[0019] Figure 10 and Figure 11 is a diagram showing an example of differentially adjusting the voltage amplitude of a touch drive signal applied to a touch sensing circuit;

[0020] Figure 12 is a diagram showing a multiplexer circuit for selectively connecting a touch electrode to a touch sensing circuit;

[0021] Figure 13 is a diagram showing an example of the configuration of a circuit for differentially adjusting the trigger time of an amplifier reset signal according to the position of a touch electrode;

[0022] Figure 14 and Figure 15 is a diagram showing an example of the configuration of a circuit for differentially adjusting the voltage amplitude of a touch drive signal according to the position of a touch electrode;

[0023] Figure 16 and Figure 17 is a diagram showing an example of a hybrid configuration for differentially adjusting the trigger time of an amplifier reset signal and the voltage amplitude of a touch drive signal according to the position of a touch electrode;

[0024] Figure 18 is a diagram showing an example of differentially adjusting the trigger time of an amplifier reset signal in a finger sensing mode and a pen sensing mode;

[0025] Figure 19 is a diagram showing an example of differentially adjusting the trigger time of an amplifier reset signal in a self - sensing mode and a mutual - sensing mode. DETAILED DESCRIPTION

[0026] Now, reference will be made in detail to the preferred embodiments of the present disclosure, examples of which are shown in the accompanying drawings. As much as possible, the same reference numerals will be used throughout the drawings to refer to the same or similar components. In the following description, detailed descriptions of known functions and configurations incorporated herein may be omitted when they may obscure the subject matter of the present disclosure.

[0027] Figure 1 and Figure 2FIG. is a diagram showing a display device having a touch sensor according to an embodiment of the present disclosure.

[0028] Reference Figure 1 and Figure 2 , a display device having a touch sensor according to the present disclosure may 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 the present disclosure is not limited to an LCD.

[0029] The display device having a touch sensor according to the present disclosure 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 circuit 20.

[0030] 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 a pixel region 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 filled with a data voltage, a storage capacitor Cst for holding 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.

[0031] 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 commonly connected to a plurality of pixels PXL and forms a single touch electrode TS. A plurality of touch electrodes arranged in a row may form a touch block line. Each touch sensor may include pixels defined by gate lines and data lines. Each touch block line overlaps a plurality of pixel lines, and one touch block line is wider than one pixel line. Here, one pixel line is composed of pixels PXL arranged in a row.

[0032] A black matrix and a color filter may be formed on the upper substrate of the display panel 10. The lower substrate of the display panel 10 may be implemented as a color on the thin film transistor (COT) structure. In this case, the black matrix and the color filter may be formed on the lower substrate of the display panel 10. A common electrode provided with a common voltage may be formed on the upper substrate or the lower substrate of the display panel 10. Polarizing plates may be attached to the upper substrate and the lower substrate of the display panel 10, and alignment films for setting a pretilt angle of the liquid crystal are formed on the inner sides of the upper substrate and the lower substrate in contact with the liquid crystal. Column spacers for maintaining a cell gap of the liquid crystal cell are formed between the upper substrate and the lower substrate of the display panel 10.

[0033] The backlight unit may be disposed on the back surface of the display panel 10. The backlight unit is implemented as an edge-type or direct-lit backlight unit and radiates light to the display panel 10. The display panel 10 may be implemented in any known liquid crystal mode, such as a twisted nematic (TN) mode, a vertical alignment (VA) mode, an in-plane switching (IPS) mode, and an fringe field switching (FFS) mode.

[0034] The timing controller 16 receives timing signals input from the host system 19, such as a vertical synchronization signal Vsync, a horizontal synchronization signal Hsync, a data enable signal DE, and a main clock signal MCLK, and controls the operating timings of the data driving circuit 12, the gate driving circuit 14, and the touch driving circuit 18. The scan timing control signals may include a gate start pulse signal GSP, a gate shift clock signal GSC, and a gate output enable signal GOE. The data timing control signals may include a source sampling clock signal SSC, a polarity control signal POL, and a source output enable signal SOE. The timing controller 16 may include Figures 12 to 15 the microcontroller unit (MCU) shown.

[0035] The timing controller 16 may divide the driving period of the display panel in time into a display driving period Pd and a touch sensor driving period Pt based on a touch synchronization signal (refer to Figure 16 , Figure 18 and Figure 19 for TSYNC therein). The data driving circuit 12, the gate driving circuit 14, and the 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 may be a high logic level and the second logic level may be a low logic level, and vice versa.

[0036] The data driving circuit 12 and the gate driving circuit 14 write the input image data RGB into the pixels PXL of the display panel 10 under the control of the timing controller 16.

[0037] The data driving circuit 12 includes a plurality of source driver integrated circuits (ICs) SIC, converts the digital image data RGB input from the timing controller 16 into an analog positive / negative gamma compensation voltage according to the scan timing control signals to generate a data voltage, and outputs the data voltage during the display driving period Pd. The data voltage output from the data driving circuit 12 is supplied to the data lines D1 to Dm.

[0038] The data driving circuit 12 applies an AC signal having the same phase and the same amplitude as the touch driving signal Tdrv applied to the touch electrode TS during the touch sensor driving period Pt (refer to Figure 3In (Sdrv) of, the parasitic capacitance between the touch electrode TS and the data lines D1 to Dm is minimized and the influence of the parasitic capacitance on the touch electrode TS is reduced. This is because when the voltages on the parasitic capacitors change simultaneously and the voltage difference is small, the charge stored in the parasitic capacitors decreases. When the influence of the parasitic capacitance on the touch electrode TS is reduced, the display noise mixed in the touch sensing result can be minimized and the distortion of the amplifier output voltage as the touch sensing signal can be prevented.

[0039] The gate driving circuit 14 generates a gate pulse signal synchronized with the data voltage with reference to the scan timing control signal, and outputs the gate pulse signal to the gate lines Gl to Gn during the display driving period Pd to select one display line to which the data voltage is to be written in the display panel 10.

[0040] The gate driving circuit 14 generates an AC signal having the same phase and the same amplitude as the touch driving signal Tdrv applied to the touch electrode TS during the touch sensor driving 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 the distortion of the amplifier output voltage as the touch sensing signal can be prevented.

[0041] The gate driving circuit 14 may be configured as a gate driver IC or may be directly formed on the lower glass substrate of the display panel 10 in an in-panel gate driver (GIP) structure.

[0042] The touch driving circuit 18 includes a readout IC RIC. The touch driving circuit 18 drives and senses the touch electrode TS included in the pixel array of the display panel 10 during the touch sensor driving period Pt. The touch electrode TS may constitute a capacitive sensor for sensing a touch input. The capacitive sensor may be implemented based on self-capacitance or mutual-capacitance. The self-capacitance and the mutual-capacitance may be formed along a single-layer wire formed in one direction, or may be formed between two orthogonal wires.

[0043] Each readout IC RIC may include a touch sensing circuit ( Figure 3 in SU) and an amplifier output control circuit. The touch sensing circuit ( Figure 3 in SU) applies a touch driving signal ( Figure 3 in Tdrv) to the touch electrode TS, and based on the amplifier reset signal (refer to Figure 4The RST in) amplifies the charge flowing out of the touch electrode TS to generate an 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, so as to improve the sensitivity deviation at the touch electrode position and improve the touch performance.

[0044] As Figure 2 shown, the readout IC RIC and the source driver IC SIC can be integrated into one chip to implement the source and readout IC SRIC. The source and readout IC SRIC can be mounted on the film-on-source chip (SCOF).

[0045] The host system 19 can transmit the timing signals Vsync, Hsync, DE, and MCLK together with the digital image data RGB to the timing controller 16, and execute an application program associated with the touch sensing data TDATA(XY) input from the touch drive circuit 18.

[0046] The host system 19 refers to the system main body of an electronic device of a display device to which the present disclosure can be applied. The host system 19 can be any one 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 the touch input data TDATA(XY) from the touch sensing IC TIC and executes an application associated with the touch input.

[0047] The power supply circuit 20 generates the driving power required for the operation of the touch drive circuit 18. The power supply circuit 20 can be implemented in the form of an integrated circuit, such as Figure 12 and Figure 14 the "touch power supply IC (TPIC)" in. As needed, the power supply circuit 20 can include an amplifier output control circuit (including Figure 14 the Tdrv regulator in).

[0048] Figure 3 is a diagram showing the configuration of the source and readout IC integrating the data drive circuit and the touch drive circuit according to the present disclosure. Figure 4 is a diagram showing the touch sensing circuit included in the source and readout IC.

[0049] Refer to Figure 3 and Figure 4, the source and readout IC SRIC includes a source driver IC SIC that drives data lines D1 to D5 of the display panel 10 and a readout IC RIC that drives touch lines SL connected to 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 separated from each other.

[0050] The source driver IC SIC includes a digital-to-analog converter that generates a data voltage Vdata and an output buffer BUF that stabilizes the data voltage Vdata. The source driver IC SIC outputs the data voltage Vdata to the data lines D1 to D5 during a display driving period and outputs an AC signal (reference Sdrv) for reducing the influence of parasitic capacitance on the data lines D1 to D5 during a touch sensor driving period.

[0051] 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 the power supply circuit 20 shown. The common voltage generator generates a common voltage required for the operation of the display. Depending on the type of display device, the common voltage may be various display voltages. For example, the common voltage may be a voltage applied to a common electrode in a liquid crystal display and may be a voltage applied to a cathode in an organic light-emitting display device.

[0052] Each multiplexer MUX selectively connects the touch sensing circuit SU and the common voltage generator to the touch electrodes under the control of the timing controller 16. When the touch screen has a resolution of M×N (M and N are positive integers equal to or greater than 2), the touch electrodes TS may be segmented into M×N touch electrode segments, and M multiplexers may be provided. Each multiplexer MUX is connected to N touch electrodes TS through N touch lines SL and sequentially connects the N touch lines SL to a single touch sensing circuit SU.

[0053] The touch sensing circuit SU is connected to the touch lines SL through the multiplexer MUX to apply a touch drive signal Tdrv to the touch electrodes TS, sense the charge flowing out of the touch electrodes TS, and generate touch sensing data TDATA.

[0054] As Figure 4 shown, the touch sensing circuit SU includes a preamplifier that amplifies the voltage of the touch capacitor CS based on an 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 touch screen has a resolution of M×N, M touch sensing circuits SU are required.

[0055] The touch capacitance CS has self-capacitance and mutual-capacitance and is formed in the touch electrode. The preamplifier is connected to the touch electrode through the touch line SL and receives the charge stored in the touch capacitance CS. A load resistance element LR and a parasitic capacitance element CP may exist on the touch line SL.

[0056] The preamplifier includes an amplifier AMP, a feedback capacitor CFB, and a reset switch SW. The inverting terminal (-) of the amplifier AMP is connected to the touch line SL and the non-inverting terminal (+) of the amplifier AMP is supplied with a touch drive signal Tdrv. The output terminal of the amplifier AMP is connected to an integrator. The feedback capacitor CFB is connected between the inverting terminal (-) and the output terminal of the amplifier AMP. The reset switch is also connected between the inverting terminal (-) and the output terminal of the amplifier AMP. The reset switch SW is turned on in synchronization with the trigger time of the amplifier reset signal RST. The preamplifier stores the charge flowing out from the touch electrode in the feedback capacitor CFB until the reset switch SW is turned on, and supplies the stored voltage as an amplifier output voltage to the integrator. This amplifier output voltage varies according to the RC value of the touch line SL based on the touch electrode position, which may cause a sensitivity deviation at the touch electrode position. Therefore, a method for improving the sensitivity deviation at the position as Figures 5 to 19 shown is proposed.

[0057] Figure 5 is a diagram showing the concept of a technique for improving the sensitivity deviation at the touch electrode position. Figure 6 and Figure 7 are diagrams showing an example of differentially adjusting the trigger time of the amplifier reset signal applied to the touch sensing circuit according to the position of the touch electrode. Figure 8 and Figure 9 are diagrams showing a specific method for adjusting the trigger time of the amplifier reset signal. Figure 10 and Figure 11 are diagrams showing an example of differentially adjusting the voltage amplitude of the touch drive signal applied to the touch sensing circuit.

[0058] Referring to Figure 5 , the amplifier output control circuit differentially controls the level of the amplifier output voltage according to the position of the touch electrode to improve the 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 according to the position of the touch electrode and a Tdrv regulator that differentially adjusts the voltage amplitude of the touch drive signal Tdrv according to the position of the touch electrode.

[0059] The RST regulator can differentially adjust the trigger time of the amplifier reset signal based on the on start timing and on duty of a predetermined amplifier reset signal according to the position of the touch electrode.

[0060] The RST regulator can adjust the trigger time of the amplifier reset signal RST to a first start time Ta for the touch electrode at the first position AR1, adjust the trigger time of the amplifier reset signal RST to a 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 a 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.

[0061] Reference Figure 6 and Figure 7 With respect to the touch electrode at the first position AR1, the preamplifier stores the charge flowing out from the touch electrode at the first position AR1 in the feedback capacitor CFB from the rising time of the touch drive signal Tdrv to the first start time Ta of the amplifier reset signal RST, and supplies the stored voltage as a first amplifier output voltage VA to the integrator. Then, the integrator accumulates the first amplifier output voltage VA multiple times (e.g., 3 times) to generate a first integrator output voltage.

[0062] Reference Figure 6 and Figure 7 With respect to the touch electrode at the second position AR2, the preamplifier stores the charge flowing out from the touch electrode at the second position AR2 in the feedback capacitor CFB from the rising 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 a second amplifier output voltage VB to the integrator. Then, the integrator accumulates the second amplifier output voltage VB multiple times (e.g., 3 times) to generate a second integrator output voltage.

[0063] In Figure 6 and Figure 7 the voltage amplitude of the touch drive signal Tdrv applied to all touch electrodes is fixed to the difference between VTH and VTL regardless of the electrode position.

[0064] Since the second start time Tb is before the first start time Ta, the level of the output voltage VB of the second amplifier is lower than the level of the output voltage VA of the first amplifier by "ΔV". Therefore, the level of the output voltage of the second integrator is lower than the level of the output voltage VA of the first integrator by "ΔAV".

[0065] In this way, the level of the output voltage of the amplifier 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 output voltage of the amplifier can be controlled to be 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 output voltage of the amplifier increases as the position of the touch electrode moves farther away from the touch sensing circuit SU, and thus the sensitivity deviation at the position of the touch electrode can be effectively reduced.

[0066] To adjust the trigger times 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 working time and different phases, as Figure 8 shown.

[0067] In addition, to adjust the trigger times 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 working times, as Figure 9 shown. Therefore, the amplifier reset signal RST with the first start time Ta can have a first working time, the amplifier reset signal RST with the second start time Tb can have a second working time, and the amplifier reset signal RST with the third start time Tc can have a third working time. In this case, the first working time is shorter than the second working time, and the second working time is shorter than the third working time. That is, referring to Figure 9 , the three amplifier reset signals RST with different working times can have the same fall time and different rise times.

[0068] As Figure 5 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, to a second value Db for the touch electrode at the second position AR2, and 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.

[0069] Referring to Figure 10 and Figure 11, regarding the touch electrode at the second position AR2, the preamplifier stores the charge flowing out from the touch electrode at the first position AR1 in the feedback capacitor CFB from the rising edge of the touch drive signal Tdrv with an amplitude of the 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. Then, the integrator accumulates the first amplifier output voltage VA multiple times (e.g., 3 times) to generate the first integrator output voltage.

[0070] Reference Figure 10 and Figure 11 , regarding the touch electrode at the second position AR2, the preamplifier stores the charge flowing out from the touch electrode at the second position AR2 in the feedback capacitor CFB from the rising edge 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. Then, the integrator accumulates the second amplifier output voltage VB multiple times (e.g., 3 times) to generate the second integrator output voltage.

[0071] At Figure 10 and Figure 11 , the start time of the amplifier reset signal RST is fixed, independent of the touch electrode position.

[0072] Since 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 lower than the level of the first integrator output voltage VA by "ΔAV".

[0073] In this way, it is possible to differentially control the level of the amplifier output voltage based on the touch electrode position according to the voltage amplitude of the touch drive signal Tdrv. The level of the amplifier output voltage can be controlled to be 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 gets farther from the touch sensing circuit SU, so the sensitivity deviation at the touch electrode position can be effectively reduced.

[0074] Figure 12 is a diagram showing a multiplexer circuit for selectively connecting a touch electrode to a touch sensing circuit, Figure 13 is a diagram showing an example of the configuration of a circuit for differentially adjusting the trigger time of an amplifier reset signal according to the position of a touch electrode.

[0075] Reference Figure 12 and Figure 13, the RST regulator can be included in the digital circuit block of the source and readout IC SRIC together with the MUX counter and the setting register. The RST regulator, the MUX counter, and the setting register are controlled by the MCU. The MCU can be mounted on the source printed circuit board SPCB together with the TPIC.

[0076] The MUX counter generates MUX count information indicating the order in which the touch electrodes TS and the touch sensing circuit SU are connected through the multiplexer MUX. The MUX count information is generated as different values according to 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 according to the position of the touch electrode TS. The information related to the amplifier reset signal RST in the setting register can be corrected by the MCU.

[0077] 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.

[0078] Figure 14 and Figure 15 is a diagram showing an example of the configuration of a circuit for differentially adjusting the voltage amplitude of the touch drive signal according to the position of the touch electrode.

[0079] As Figure 14 shown, the Tdrv regulator can be included in the TPIC, or as Figure 15 shown, the Tdrv regulator can be included in the analog circuit block of the source and readout IC SRIC.

[0080] In Figure 14 and Figure 15 as Figure 13 shown, the MUX counter is mounted in the digital circuit block of the source and readout IC SRIC. The MUX counter generates MUX count information indicating the order in which the touch electrode TS and the touch sensing circuit SU are connected through the multiplexer MUX. The MUX count information is generated as different values according to the position of the touch electrode TS.

[0081] The Tdrv regulator detects the position of the touch electrode TS according to the MUX count information and adjusts the voltage amplitude of the touch drive signal Tdrv according to the position. The Tdrv regulator supplies the touch drive signal Tdrv with the 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.

[0082] Figure 16 and Figure 17 is a diagram showing an example of a hybrid configuration for differentially adjusting the trigger time of an amplifier reset signal and the voltage amplitude of a touch drive signal according to the position of a touch electrode.

[0083] Reference Figure 12 、 Figure 16 and Figure 17 , the position of the touch electrode connected through the first multiplexer MUX1 is the farthest from the touch sensing circuit SU, and the position of the touch electrode connected through the nth multiplexer MUXn is the closest to the touch sensing circuit SU.

[0084] 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.

[0085] 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 through 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 through the first multiplexer MUX1, and adjust the trigger time of the second amplifier reset signal RST to Tb for the second touch electrode connected through the second multiplexer MUX2. The amplifier output control circuit can control the working time of the first amplifier reset signal RST to be shorter than that of the second amplifier reset signal RST, so that the amplifier output voltage of the first touch electrode is higher than that of the second touch electrode.

[0086] 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 through 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 through the third multiplexer MUX3, and adjust the trigger time of the fourth amplifier reset signal RST to Tb’ for the fourth touch electrode connected through the fourth multiplexer MUX4. The amplifier output control circuit can control the working 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.

[0087] 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 n-th 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 n-th amplifier reset signal RST to Tb” for the n-th touch electrode connected through the n-th multiplexer MUXn. The amplifier output control circuit can control the working time of the (n - 1)-th amplifier reset signal RST to be shorter than that of the n-th amplifier reset signal RST, such that the amplifier output voltage of the (n - 1)-th touch electrode is higher than that of the n-th touch electrode.

[0088] Figure 18 is a diagram showing an example of differential adjustment of the trigger time of the amplifier reset signal in the finger sensing mode and the pen sensing mode, Figure 19 is a diagram showing an example of differential adjustment of the trigger time of the amplifier reset signal in the self-capacitance sensing mode and the mutual-capacitance sensing mode.

[0089] Reference Figure 18 , during the touch sensor driving period Pt, the touch sensing circuit can implement the finger sensing mode and the pen sensing mode. The touch sensing circuit generates an amplifier output voltage according to the finger touch input in the finger sensing mode, and generates an amplifier output voltage according to the pen touch input in the pen sensing mode. For the touch electrodes at the same position, the touch sensitivities in the finger sensing mode and the pen sensing mode may be different.

[0090] For the touch electrodes at the same position, the amplifier output circuit can adjust the trigger time of the amplifier reset signal RST to the first start time in the 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 the finger sensing mode, so as to improve the touch sensitivity deviation between the sensing modes.

[0091] Reference Figure 19 , during the touch sensor driving period Pt, the touch sensing circuit can implement the self-capacitance sensing mode and the mutual-capacitance sensing mode. The touch sensing circuit generates an amplifier output voltage based on self-capacitance according to the touch input in the self-capacitance sensing mode, and generates an amplifier output voltage based on mutual-capacitance according to the touch input in the mutual-capacitance sensing mode. For the touch electrodes at the same position, the touch sensitivities in the self-capacitance sensing mode and the mutual-capacitance sensing mode may be different.

[0092] For touch electrodes at the same position, the amplifier output circuit can adjust the trigger time of the amplifier reset signal RST to a first start time in the self-inductance mode and to a second start time before the first start time in the mutual-inductance mode to improve the touch sensitivity deviation between sensing modes.

[0093] Obviously, for those skilled in the art, various modifications and changes can be made to the present disclosure without departing from the spirit or scope of the present disclosure. Therefore, the present disclosure is intended to cover modifications and changes of the present disclosure as long as they fall within the scope of the appended claims and their equivalents.

[0094] A display device having a touch sensor according to an embodiment of the present disclosure can improve the sensitivity deviation at the touch electrode position to improve touch performance.

[0095] In addition, a display device having a touch sensor according to an embodiment of the present disclosure can improve the sensitivity deviation between sensing modes to improve touch performance.

Claims

1. A display device having a touch sensor, comprising: a display panel including a plurality of touch electrodes; a touch sensing circuit configured to apply a touch driving signal to the touch electrodes and amplify charges flowing in from 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 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 electrodes, wherein the amplifier output control circuit includes at least one of a first regulator and a second regulator, the first regulator is configured to differentially adjust the trigger time of the amplifier reset signal according to the position of the touch electrodes, the second regulator is configured to differentially adjust the voltage amplitude of the touch driving signal according to the position of the touch electrodes, and wherein the first regulator is configured to differentially adjust the trigger time of the amplifier reset signal based on a start time and a working time of the amplifier reset signal preset according to the position of the touch electrodes.

2. The display device having a touch sensor according to claim 1, wherein, For the touch electrodes at a first position, the first regulator adjusts the trigger time of the amplifier reset signal to a first start time, and for the touch electrodes at a second position, the first regulator adjusts the trigger time of the amplifier reset signal to a second start time before the first start time, wherein the first position is farther from the touch sensing circuit than the second position.

3. The display device with a touch sensor according to claim 2, wherein, The amplifier reset signal having the first start time and the amplifier reset signal having the second start time have the same working time and different phases.

4. The display device with a touch sensor according to claim 2, wherein, The amplifier reset signal having the first start time has a first working time, and the amplifier reset signal having the second start time has a second working time, wherein the first working time is shorter than the second working time.

5. The display device with a touch sensor according to claim 1, wherein, For the touch electrodes at a first position, the second regulator is configured to adjust the voltage amplitude of the touch driving signal to a first value, and for the touch electrodes at a second position, the second regulator adjusts the voltage amplitude of the touch driving signal to a second value less than the first value, wherein the first position is farther from the touch sensing circuit than the second position.

6. The display device with a touch sensor according to claim 5, wherein, When a touch sensing period and a display period are alternately arranged multiple times in a frame, in the display period, the second regulator is configured to adjust the voltage amplitude of the touch driving signal to the first value or the second value.

7. The display device with a touch sensor according to claim 1, wherein, The touch sensing circuit is configured to generate the amplifier output voltage according to a finger touch input in a finger sensing mode and generate the amplifier output voltage according to a pen touch input in a pen sensing mode, and For a touch electrode at the same position, the amplifier output circuit is configured to adjust the trigger time of the amplifier reset signal to a first starting time in the pen sensing mode, and adjust the trigger time of the amplifier reset signal to a second starting time before the first starting time in the finger sensing mode.

8. The display device with a touch sensor according to claim 1, wherein, The touch sensing circuit is configured to generate the amplifier output voltage based on self-capacitance according to a touch input in the self-sensing mode, and generate the amplifier output voltage based on mutual-capacitance according to a touch input in the mutual-sensing mode, and For a touch electrode at the same position, the amplifier output circuit is configured to adjust the trigger time of the amplifier reset signal to a first starting time in the self-sensing mode, and adjust the trigger time of the amplifier reset signal to a second starting time before the first starting time in the mutual-sensing mode.

9. A method for driving a display device having a touch sensor, comprising: Applying a touch driving signal to a touch electrode of a display panel, and amplifying a charge flowing in from the touch electrode based on an amplifier reset signal to generate an amplifier output voltage; And Differentially adjusting the trigger time of the amplifier reset signal according to the position of the touch electrode or the voltage amplitude of the touch driving signal, so as to differentially control the level of the amplifier output voltage according to the position of the touch electrode, wherein the trigger time of the amplifier reset signal is differentially adjusted based on a starting time and a working time of the amplifier reset signal preset according to the position of the touch electrode.

10. A display device having a touch sensor, comprising: A display panel, the display panel including a plurality of touch electrodes; A touch driving circuit, the touch driving circuit including a readout IC, each readout IC 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 electrode, and amplify a charge flowing out from the touch electrode 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, so as to differentially control the level of the amplifier output voltage according to the position of the touch electrode, wherein the amplifier output control circuit includes at least one of a first regulator and a second regulator, the first regulator is configured to differentially adjust the trigger time of the amplifier reset signal according to the position of the touch electrode, the second regulator is configured to differentially adjust the voltage amplitude of the touch driving signal according to the position of the touch electrode, and wherein the first regulator is configured to differentially adjust the trigger time of the amplifier reset signal based on a starting time and a working time of the amplifier reset signal preset according to the position of the touch electrode.

11. The display device with a touch sensor according to claim 10 further includes a data driving circuit. The data driving circuit includes a plurality of source driver ICs for driving a plurality of data lines of the display panel, and the readout IC and the source driver SIC are integrated into a source and readout IC.

12. The display device with a touch sensor according to claim 11, wherein, The source and readout IC is mounted on a film source chip.

13. The display device with a touch sensor according to claim 10, wherein, For the touch electrode at the first position, the first regulator is configured to adjust the triggering time of the amplifier reset signal to a first start time, and for the touch electrode at the second position, the first regulator adjusts the triggering time of the amplifier reset signal to a second start time before the first start time. Wherein, the first position is farther from the touch sensing circuit than the second position.

14. The display device with a touch sensor according to claim 13, wherein, The touch sensing circuit includes: a preamplifier configured to amplify the voltage of a touch capacitor based on the amplifier reset signal; an integrator configured to accumulate the amplifier output voltage of the preamplifier; and an analog-to-digital converter configured to convert the output voltage of the integrator into digital data. Wherein, the preamplifier includes an amplifier, a feedback capacitor, and a reset switch.

15. The display device with a touch sensor according to claim 14, wherein, For the touch electrode at the first position, the preamplifier is configured to store the charge flowing out of the touch electrode at the first position from the rising time of the touch driving signal to the first start time of the amplifier reset signal in the feedback capacitor, and supply the stored voltage as a first amplifier output voltage to the integrator. The integrator is configured to accumulate the first amplifier output voltage multiple times to generate a first integrator output voltage. For the touch electrode at the second position, the preamplifier is configured to store the charge flowing out of the touch electrode at the second position from the rising time of the touch driving signal to the second start time of the amplifier reset signal in the feedback capacitor, and supply the stored voltage as a second amplifier output voltage to the integrator. The integrator is configured to accumulate the second amplifier output voltage multiple times to generate a second integrator output voltage, and The level of the second amplifier output voltage is lower than the level of the first amplifier output voltage.

16. The display device with a touch sensor according to claim 10, wherein, The readout IC further includes a multiplexer and a common voltage generator, and each multiplexer selectively connects the touch sensing circuit and the common voltage generator to the touch electrode.

17. The display device with a touch sensor according to claim 10, wherein, For the touch electrode at the first position, the second regulator is configured to adjust the voltage amplitude of the touch driving signal to a first value, and for the touch electrode at the second position, the second regulator adjusts the voltage amplitude of the touch driving signal to a second value less than the first value. Wherein, the first position is farther from the touch sensing circuit than the second position.

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