Touch display device and method for driving touch display device

Abstract

A touch display device and a method for driving the touch display device are disclosed. The touch display device includes: a touch display panel that displays an image and senses touch; a plurality of touch electrodes that are arranged on the touch display panel and divided into a plurality of blocks; a plurality of gate lines that are arranged on the touch display panel and overlap the plurality of touch electrodes; and a touch display driving unit that supplies a common voltage to the plurality of touch electrodes and a gate voltage to the plurality of gate lines, wherein the common voltage has a first voltage before and after a first compensation period and has a second voltage lower than the first voltage during the first compensation period, the first compensation period corresponding to a high level period of the gate voltage supplied to a gate line among the plurality of gate lines that first overlaps with a touch electrode among the plurality of touch electrodes.

Description

[0001] CROSS-REFERENCE TO RELATED APPLICATIONS

[0002] This application claims the benefit of priority to Korean Patent Application No. 10-2020-0186956 filed in Korea on December 30, 2020, the entire contents of which are hereby incorporated herein by reference. Technical Field

[0003] The present disclosure relates to a touch display device, and more particularly, to a touch display device and a method for driving the touch display device in which a ripple of a common voltage is compensated by modulating a common voltage to have a different value in synchronization with a gate voltage of a gate line overlapping a rising portion and a falling portion of a touch electrode. Background Art

[0004] With the development of the information age, display devices have rapidly improved. Liquid crystal display (LCD) devices, organic light emitting diode (OLED) display devices, and field emission display (FED) devices have been developed and widely used as flat panel displays (FPDs) with thin profiles, light weight, and low power consumption. Conventional cathode ray tubes (CRTs) have been rapidly replaced by FPDs.

[0005] Recently, a touch display device, which is called a touch screen and in which a touch panel is provided on a display panel, has been widely used.

[0006] The touch display device is used as an output device for displaying an image and as an input device for receiving a user's command by touching a portion of the image. The touch panel of the touch display device can be classified into a resistive type, a capacitive type, an infrared type, and a surface acoustic wave type according to a method of detecting position information.

[0007] When a user views an image of the display panel and touches the touch panel, the touch panel detects position information of the touched portion and recognizes the user's command by comparing the detected position information with position information of the image.

[0008] In the touch display device, the touch panel may be attached to the display panel, or the touch panel may be integrated on a substrate of the display panel as an in-cell type.

[0009] Capacitive type touch display devices may be classified into a self-capacitive type and a mutual-capacitive type. In a self-capacitive type touch display device, a common electrode for image display is divided into a plurality of blocks, and a common electrode of each block is used as a touch electrode for touch sensing.

[0010] Since the common electrode is not formed over the entire area but is formed separately for each area, there is a problem of occurrence of ripples in which the voltage value of the common voltage applied to the common electrode fluctuates due to coupling with the gate voltage of the gate line overlapping the common electrode.

[0011] Specifically, the gate voltage is sequentially applied to a plurality of gate lines overlapping the common electrode of each block. In the central portion of the common electrode, both the falling edge of the corresponding gate voltage and the rising edge of the corresponding gate voltage appear. In the upper portion of the common electrode, only the rising edge of the corresponding gate voltage appears, and in the lower portion of the common electrode, only the falling edge of the corresponding gate voltage appears.

[0012] Therefore, a difference in ripples of the upper portion, the center portion, and the lower portion of the common electrode occurs, and a difference in the average value of the common electrode occurs to cause degradation such as bright lines. Summary of the invention

[0013] Accordingly, the present disclosure is directed to a touch display device and a method of driving the same that substantially obviate one or more of the problems due to limitations and disadvantages of the related art.

[0014] An object of the present disclosure is to provide a touch display device and a method for driving the touch display device, in which a common voltage is modulated to have different values ​​in synchronization with a gate voltage of a gate line overlapping a rising portion and a falling portion of a touch electrode to compensate for ripples of the common voltage and reduce or prevent degradation such as bright lines.

[0015] Another object of the present disclosure is to provide a touch display device and a method for driving the touch display device, in which the common voltage is reduced during the high-level period of the gate voltage of the gate line that first overlaps the touch electrode and the common voltage is increased during a period delayed by one horizontal period compared with the high-level period of the gate voltage of the gate line that last overlaps the touch electrode, so that the average value of the common voltage is kept constant and the display quality is improved.

[0016] Additional features and advantages of the present disclosure will be set forth in the following description, and in part will become apparent from the description, or may be learned through the practice of the present disclosure. These and other advantages of the present disclosure will be realized and obtained through the structures particularly pointed out in the written description and claims herein and the drawings.

[0017] To achieve these and other advantages and in accordance with the purpose of the present disclosure, as implemented and broadly described herein, a touch display device and a method for driving the touch display device are provided. In one aspect, the touch display device includes: a touch display panel that displays an image and senses touch; a plurality of touch electrodes that are disposed on the touch display panel and divided into a plurality of blocks; a plurality of gate lines that are disposed on the touch display panel and overlap the plurality of touch electrodes; and a touch display driving unit that supplies a common voltage to the plurality of touch electrodes and a gate voltage to the plurality of gate lines, wherein the common voltage has a first voltage before and after a first compensation period and has a second voltage lower than the first voltage during the first compensation period, the first compensation period corresponding to a high level period of the gate voltage supplied to a gate line among the plurality of gate lines that first overlaps with one of the plurality of touch electrodes.

[0018] On the other hand, a method for driving a touch display device includes: supplying a common voltage to multiple touch electrodes of the touch display device; supplying a gate voltage to multiple gate lines of the touch display device; and displaying an image in a touch display panel of the touch display device using the common voltage and the gate voltage, wherein supplying the common voltage includes: supplying a first voltage as the common voltage before and after a first compensation period, the first compensation period corresponding to a high-level period of the gate voltage supplied to a gate line among multiple gate lines that first overlaps with a touch electrode among multiple touch electrodes; and during the first compensation period, supplying a second voltage lower than the first voltage as the common voltage.

[0019] It is to be understood that both the foregoing general description and the following detailed description are explanatory and are intended to provide further explanation of the disclosure as claimed. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] The accompanying drawings, which are included to provide a further understanding of the present disclosure and are incorporated in and constitute a part of this specification, illustrate embodiments of the present disclosure and, together with the description, serve to explain the principles of the present disclosure. In the drawings:

[0021] Figure 1 is a view showing a touch display device according to an embodiment of the present disclosure;

[0022] Figure 2 is a view showing gate lines and touch electrodes of a touch display device according to an embodiment of the present disclosure;

[0023] Figure 3A is a view showing a gate voltage and a common voltage in a rising portion of a touch display device according to an embodiment of the present disclosure;

[0024] Figure 3B is a view showing an ascending and descending portion of a touch display device according to an embodiment of the present disclosure;

[0025] Figure 3C is a view showing a descending portion of a touch display device according to an embodiment of the present disclosure;

[0026] Figure 4 is a view of a power supply part and a touch display driving part of a touch display device according to an embodiment of the present disclosure; and

[0027] Figure 5 is a view showing signals of a power supply part of a touch display device according to an embodiment of the present disclosure. DETAILED DESCRIPTION

[0028] The advantages and features of the present disclosure and their implementation methods will be explained by the following example embodiments described with reference to the accompanying drawings. However, the present disclosure can be implemented in different forms and should not be construed as being limited to the example embodiments set forth herein. Rather, these example embodiments are provided so that the present disclosure can be sufficiently thorough and complete to help those skilled in the art fully understand the scope of the present disclosure. In addition, the present disclosure is limited only by the scope of the claims.

[0029] The shapes, sizes, ratios, angles and quantities disclosed in the drawings for describing the embodiments of the present disclosure are merely examples. Therefore, the present disclosure is not limited to the details shown. Throughout the text, the same reference numerals refer to the same elements. In the following description, when it is determined that a detailed description of the relevant known functions or configurations will unnecessarily obscure the focus of the present disclosure, the detailed description of such known functions or configurations may be omitted. In the case of using the terms "comprising", "having" and "including" described in this specification, additional components may be added unless more restrictive terms such as "only" are used. Terms in the singular may include plural forms unless otherwise mentioned.

[0030] Although an error or tolerance range is not explicitly described when interpreting an element, the element is interpreted as including such error or tolerance range.

[0031] When describing a positional relationship, when the positional relationship between two components is described as, for example, "on," "over," "below," or "beside," one or more other components may be disposed between the two components, unless more restrictive terms such as "only" or "directly" are used.

[0032] It should be understood that although the terms "first", "second", etc. may be used herein to describe various elements, these elements should not be limited by these terms. These terms are only used to distinguish one element from another element. For example, a first element may be referred to as a second element, and similarly, a second element may be referred to as a first element without departing from the scope of the present disclosure.

[0033] As those skilled in the art can fully understand, the features of the various embodiments of the present disclosure can be coupled or combined with each other in part or in whole, and can interoperate and be driven technically differently from each other. The embodiments of the present disclosure can be performed independently of each other, or can be performed together in a mutually dependent relationship.

[0034] Hereinafter, a touch display device according to an embodiment of the present disclosure and a method for driving the touch display device will be described in detail with reference to the accompanying drawings. In the following description, the same reference numerals refer to the same elements throughout the text. When it is determined that a detailed description of a known function or configuration related to this document will unnecessarily confuse the main points of the inventive concept, its detailed description will be omitted or will be brief.

[0035] Figure 1 2 is a view showing a touch display device according to an embodiment of the present disclosure. For example, the touch display device according to an embodiment of the present disclosure may be a self-capacitive in-cell type.

[0036] exist Figure 1 In the embodiment of the present disclosure, the touch display device 110 includes a touch display panel 120 and a touch display driving unit 130 .

[0037] The touch display panel 120 displays an image and senses a touch. For touch sensing, the touch display panel 120 includes a plurality of touch electrodes TE divided into a plurality of blocks and a plurality of touch lines TL connecting the plurality of touch electrodes TE and the touch display driving part 130, respectively.

[0038] For example, the plurality of touch electrodes TE may be arranged in a matrix shape.

[0039] Although not shown, for image display, the touch display panel 120 may include a first substrate, a plurality of gate lines, a plurality of data lines, a plurality of thin film transistors (TFTs) and a plurality of pixel electrodes. The gate lines and the data lines are arranged on the first substrate and cross each other to define a plurality of pixel regions. Each TFT is arranged in a corresponding pixel region and is connected to a corresponding gate line and data line. Each pixel electrode is arranged in a corresponding pixel region and is connected to a corresponding TFT.

[0040] The touch display panel 120 may be an organic light emitting diode (OLED) panel or a liquid crystal panel. The touch display panel 120 of the OLED panel may further include a plurality of light emitting diodes and a passivation layer covering the light emitting diodes, each light emitting diode being connected to a corresponding pixel electrode. The touch display panel 120 of the liquid crystal panel may further include a second substrate facing the first substrate, a common electrode under the second substrate, and a liquid crystal layer between the first substrate and the second substrate.

[0041] When the touch display panel 120 is an OLED panel, the second electrode of the light emitting diode may be used as the touch electrode TE. When the touch display panel 120 is a liquid crystal panel, the common electrode may be used as the touch electrode TE.

[0042] The touch display driving part 130 supplies signals for image display and touch sensing to the touch display panel 120 .

[0043] For example, during a display period for displaying an image, the touch display driving part 130 supplies gate voltages and data voltages to gate lines and data lines of the touch display panel 120 , respectively, and supplies a common voltage to the touch electrodes TE through a plurality of touch lines TL of the touch display panel 120 .

[0044] Therefore, the touch display device 110 displays an image using the gate voltage and the data voltage.

[0045] In addition, during a touch period for sensing a touch, the touch display driving part 130 supplies a touch voltage to the touch electrode TE through the corresponding touch line TL of the touch display panel 120 .

[0046] Therefore, the touch display device 110 senses a touch by analyzing a change in a touch voltage.

[0047] Hereinafter, a touch electrode TE of a block overlapping a plurality of gate lines will be described with reference to the accompanying drawings.

[0048] Figure 2 is a view showing gate lines and touch electrodes of a touch display device according to an embodiment of the present disclosure.

[0049] exist Figure 2 , the touch electrode TE of the block touching the display panel 120 overlaps the first to n-th gate lines GL1 to GL(n). The first gate line GL1 may be referred to as the gate line that first overlaps the touch electrode TE, and the n-th gate line GL(n) may be referred to as the gate line that last overlaps the touch electrode TE.

[0050] The touch electrode TE may include: a rising portion RA overlapping with the first gate line GL1 to the third gate line GL3, in which only a rising edge of a gate voltage appears; a rising falling portion RFA overlapping with the fourth gate line GL4 to the (n-3)th gate line GL(n-3), in which both a rising edge and a falling edge of the gate voltage appear; and a falling portion FA overlapping with the (n-2)th gate line GL(n-2) to the nth gate line GL(n), in which only a falling edge of the gate voltage appears.

[0051] In the display period of the image display of the touch display device 110 of the embodiment of the present disclosure, a common voltage with a relatively low voltage value is supplied while applying a gate voltage to the first to third gate lines GL1 to GL3 of the rising portion RA, and a common voltage with a relatively high voltage value is supplied while applying a gate voltage to the (n-2)th to nth gate lines GL(n-2). Therefore, the ripple of the common voltage is reduced or minimized and degradation such as bright lines is reduced or prevented.

[0052] Hereinafter, gate voltages and common voltages in the rising portion RA, the rising falling portion RFA, and the falling portion FA will be described with reference to the accompanying drawings.

[0053] Figure 3A , Figure 3B and Figure 3C 1 and 2 are views respectively illustrating gate voltages and common voltages in a rising portion, a rising-falling portion, and a falling portion of a touch display device according to an embodiment of the present disclosure.

[0054] exist Figure 3A , Figure 3B and Figure 3C , the first to nth gate voltages Vgl to Vgn are respectively applied to the first to nth gate lines GL1 to GL(n) overlapping the touch electrodes TE of the touch display device 110 according to the embodiment of the present disclosure. Each of the first to nth gate voltages Vgl to Vgn has a high level period Ph of a high level voltage.

[0055] The high level period Ph has a width corresponding to three times (three horizontal periods: 3H) of one horizontal period (1H) (which is a time for applying a data voltage to a pixel area corresponding to one gate line of the touch display panel 120). The high level period Ph of the first gate voltage Vg1 to the nth gate voltage Vgn is shifted by one horizontal period (1H). For example, the high level period Ph of Vg2 is shifted by one horizontal period (1H) relative to the high level period Ph of Vg1, the high level period Ph of Vg3 is shifted by one horizontal period (1H) relative to the high level period Ph of Vg2, and the like.

[0056] The high level period Ph of the first gate voltage Vgl to the nth gate voltage Vgn is sequentially applied to the first gate line GL1 to the nth gate line GL(n). In this context, the first gate line GL1 is referred to as the "gate line that overlaps the touch electrode TE first" and the nth gate line GL(n) is referred to as the "gate line that overlaps the touch electrode TE last" can be understood to mean, for example: in the high level period Ph of the first gate voltage Vg1 to the nth gate voltage Vgn, the high level period Ph of the first gate voltage Vg1 occurs first, and the high level period Ph of the nth gate voltage Vgn occurs last.

[0057] like Figure 3A As shown, in the rising portion RA of the touch electrode TE of the touch display device 110, the rising edge Tr of the first gate voltage Vgl to the third gate voltage Vg3 of the first gate line GL1 to the third gate line GL3 does not overlap with the rising edge Tr and the falling edge Tf of the fourth gate voltage Vg4 to the nth gate voltage Vgn of the fourth gate line GL4 to the nth gate line GL(n).

[0058] Therefore, in the rising portion RA of the touch electrode TE of the touch display device 110, due to the coupling caused by the rising edges Tr of the first gate voltage Vg1 to the third gate voltage Vg3 of the first gate line GL1 to the third gate line GL3, the common voltage applied to the touch electrode TE during the display period has only a rising ripple component.

[0059] When the supply common voltage SVcom of the first voltage V1 is supplied to the touch electrode TE during the first compensation period Ps1 of the high level period Ph of the first gate voltage Vg1 corresponding to the rising edge Tr of the first gate voltage Vg1 to the third gate voltage Vg3, the comparison common voltage CVcom of the real voltage of the touch electrode TE has only a rising ripple component due to the coupling caused by the rising edge Tr of the first gate voltage Vg1 to the third gate voltage Vg3. Therefore, during one horizontal period (1H), the comparison common voltage CVcom is not stabilized to the first voltage V1 of the supply common voltage SVcom, but takes a voltage value with a larger rising deviation ΔVr than the first voltage V1. Therefore, degradation such as bright lines may occur.

[0060] In the touch display device 110 according to an embodiment of the present disclosure, during a first compensation period Ps1 of a high-level period Ph corresponding to a rising edge Tr of a first gate voltage Vg1 among the first gate voltage Vg1 to a third gate voltage Vg3, a supply common voltage SVcom of a second voltage V2 (V2 < Vl) lower than a first voltage Vl is supplied to a touch electrode TE. Accordingly, although a ripple component increases due to coupling of the rising edges Tr of the first gate voltage Vg1 to the third gate voltage Vg3, during one horizontal period (1H), a measurement common voltage MVcom of a true voltage of the touch electrode TE is stabilized to the first voltage V1 of the supply common voltage SVcom. Accordingly, deterioration such as bright lines is reduced or prevented.

[0061] Here, the second voltage V2 may be a value corresponding to approximately 60% of an average of rising peaks of a rising ripple component. For example, the average of rising peaks may be approximately 35 mV, and the second voltage V2 may be a value obtained by subtracting approximately 21 mV from the first voltage V1 (V1 - 21 mV). The average of rising peaks may drop to approximately 17 mV (ripple reduction of approximately 48%).

[0062] As Figure 3B shown, in a rising and falling portion RFA of the touch electrode TE of the touch display device 110, a rising edge Tr of a fourth gate voltage Vg4 to an (n - 3)th gate voltage Vg(n - 3) of a fourth gate line GL4 to an (n - 3)th gate line GL(n - 3) overlaps a falling edge Tf of one of the first gate voltage Vg1 to an nth gate voltage Vgn, and a falling edge Tf of the fourth gate voltage Vg4 to the (n - 3)th gate voltage Vg(n - 3) of the fourth gate line GL4 to the (n - 3)th gate line GL(n - 3) overlaps a rising edge Tr of another one of the first gate voltage Vg1 to the nth gate voltage Vgn.

[0063] For example, a rising edge Tr of a pth gate voltage Vgp among the fourth gate voltage Vg4 to the (n - 3)th gate voltage Vg(n - 3) overlaps a falling edge Tf of a (p - 3)th gate voltage Vg(p - 3), and a falling edge Tf of the pth gate voltage Vgp overlaps a rising edge Tr of a (p + 3)th gate voltage Vg(p + 3).

[0064] Therefore, in the rising and falling part RFA of the touch electrode TE of the touch display device 110, due to the coupling caused by the rising edge Tr of one gate voltage among the first gate voltage Vg1 to the nth gate voltage Vgn of the first gate line GL1 to the nth gate line GL(n) and the falling edge Tf of another gate voltage among the first gate voltage Vg1 to the nth gate voltage Vgn, the common voltage applied to the touch electrode TE during the display period has both a rising ripple component and a falling ripple component.

[0065] In the touch display device 110 according to an embodiment of the present disclosure, a rising edge Tr of a fourth gate voltage Vg4 to a (n-3)th gate voltage Vg(n-3) of the fourth gate line GL4 to the (n-3)th gate line GL(n-3) overlaps with a falling edge Tf of one gate voltage among the first gate voltage Vg1 to the nth gate voltage Vgn, and a falling edge Tf of a fourth gate voltage Vg4 to a (n-3)th gate voltage Vg(n-3) of the fourth gate line GL4 to the (n-3)th gate line GL(n-3) overlaps with a rising edge Tr of another gate voltage among the first gate voltage Vg1 to the nth gate voltage Vgn. Therefore, due to the coupling caused by the rising edge Tr of one gate voltage among the first gate voltage Vg1 to the nth gate voltage Vgn of the first gate line GL1 to the nth gate line GL(n) and the falling edge Tf of the other gate voltage among the first gate voltage Vg1 to the nth gate voltage Vgn of the first gate line GL1 to the nth gate line GL(n), the measurement common voltage MVcom of the real voltage of the touch electrode TE has a rising ripple component and a falling ripple component. Therefore, the measurement common voltage MVcom of the real voltage of the touch electrode TE is stabilized to the first voltage V1 of the supply common voltage SVcom during one horizontal period (1H), and degradation such as bright lines is reduced or prevented.

[0066] like Figure 3C As shown, in the falling portion FA of the touch electrode TE of the touch display device 110, the falling edge Tf of the (n-2) gate voltage Vg(n-2) to the n gate voltage Vgn of the (n-2) gate line GL(n-2) to the n gate line GL(n) does not overlap with the rising edge Tr and the falling edge Tf of the first gate voltage Vg1 to the (n-3) gate voltage Vg(n-3) of the first gate line GL1 to the (n-3) gate line GL(n-3).

[0067] Therefore, in the falling portion FA of the touch electrode TE of the touch display device 110, due to the coupling caused by the falling edge Tf of the (n-2)th gate voltage Vg(n-2) to the nth gate voltage Vgn of the (n-2)th gate line GL(n-2) to the nth gate line GL(n), the common voltage applied to the touch electrode TE during the display period has only a falling ripple component.

[0068] When the supply common voltage SVcom of the first voltage V1 is supplied to the touch electrode TE during the second compensation period Ps2 delayed by one horizontal period (1H) from the high level period Ph of the nth gate voltage Vgn corresponding to the falling edge Tf of the (n-2)th gate voltage Vg(n-2) to the nth gate voltage Vgn, the comparison common voltage CVcom of the real voltage of the touch electrode TE has only a falling ripple component due to the coupling caused by the falling edge Tf of the (n-2)th gate voltage Vg(n-2) to the nth gate voltage Vgn. Therefore, during one horizontal period (1H), the comparison common voltage CVcom is not stabilized to the first voltage V1 of the supply common voltage SVcom, but takes a voltage value with a smaller falling deviation ΔVf than the first voltage V1. Therefore, degradation such as dark lines may occur.

[0069] In the touch display device 110 according to an embodiment of the present disclosure, during the second compensation period Ps2 delayed by one horizontal period (1H) from the high level period Ph of the nth gate voltage Vgn corresponding to the falling edge Tf of the (n-2)th gate voltage Vg(n-2) to the nth gate voltage Vgn, the supply common voltage SVcom of the third voltage V3 (V3>V1) higher than the first voltage Vl is supplied to the touch electrode TE. Therefore, although the ripple component decreases due to the coupling of the falling edge Tf of the (n-2)th gate voltage Vg(n-2) to the nth gate voltage Vgn, during one horizontal period (1H), the measurement common voltage MVcom of the real voltage of the touch electrode TE is stabilized to the first voltage V1 of the supply common voltage SVcom. Therefore, degradation such as dark lines is reduced or prevented.

[0070] Here, the third voltage V3 may be a value corresponding to about 60% of the falling peak average value of the falling ripple component. For example, the falling peak average value may be about -42 mV, and the third voltage V3 may be a value obtained by adding about 25 mV to the first voltage V1 (V1+25 mV). The falling peak average value may drop to about -22 mV (ripple reduction of about 48%).

[0071] A supply common voltage SVcom of first to third voltages V1 to V3 generated using a multiplexer (MUX) will be illustrated with reference to the accompanying drawings.

[0072] Figure 4is a view showing a power supply portion and a touch display driving portion of a touch display device according to an embodiment of the present disclosure, and Figure 5 is a view showing signals of a power supply part of a touch display device according to an embodiment of the present disclosure.

[0073] exist Figure 4 and Figure 5 , the touch display device 110 according to an embodiment of the present disclosure includes a power supply part 150 . The power supply part 150 generates a supply common voltage SVcom and transmits the supply common voltage SVcom to the touch display driving part 130 .

[0074] The power supply section 150 includes a power management section 152 and a multiplexer (MUX) 154 .

[0075] The power management section 152 transfers the first voltage V1 as a reference common voltage to the MUX 154. For example, the power management section 152 may have a shape such as a power management integrated circuit (PMIC).

[0076] The MUX 154 receives the first voltage V1 from the power management section 152, and receives a second voltage V2 lower than the first voltage V1 and a third voltage V3 higher than the first voltage V1 from an external power source (not shown).

[0077] For example, the first voltage V1 may be adjusted in units of about 10 mV, and the second voltage V2 and the third voltage V3 may be adjusted in units of several mV to several tens of mV (eg, in units of about 1 mV to about 99 mV).

[0078] The MUX 154 outputs one of the first to third voltages V1 to V3 as the supply common voltage SVcom according to the first and second compensation signals CS1 to CS2.

[0079] The first compensation signal CS1 has a high level voltage during the first compensation period Ps1 corresponding to the high level period Ph of the first gate voltage Vgl, and has a low level voltage during other periods (in other words, during the remaining periods; in other words, during the periods other than the first compensation period Ps1).

[0080] The second compensation signal CS2 has a high level voltage during the second compensation period Ps2 corresponding to the high level period Ph of the nth gate voltage Vgn delayed by one horizontal period (1H), and has a low level voltage during other periods (in other words, during the remaining periods; in other words, during the periods other than the second compensation period Ps2).

[0081] When both the first compensation signal and the second compensation signal have a low level voltage ("00") or a high level voltage ("11"), the MUX 154 outputs the first voltage V1 as the supply common voltage SVcom. When the first compensation signal CS1 and the second compensation signal CS2 have a high level voltage and a low level voltage ("10"), respectively, the MUX 154 outputs the second voltage V2 as the supply common voltage SVcom. When the first compensation signal CS1 and the second compensation signal CS2 have a low level voltage and a high level voltage ("01"), respectively, the MUX 154 outputs the third voltage V3 as the supply common voltage SVcom.

[0082] The power supply section 150 of the touch display device 110 according to the embodiment of the present disclosure outputs the second voltage V2 lower than the first voltage V1 as the supply common voltage SVcom during the first compensation period Ps1 corresponding to the high level period Ph of the first gate voltage Vg1, and outputs the third voltage V3 higher than the first voltage V1 as the supply common voltage SVcom during the second compensation period Ps2 corresponding to the high level period Ph of the nth gate voltage Vgn delayed by one horizontal period (1H). The power supply section 150 of the touch display device 110 according to the embodiment of the present disclosure outputs the first voltage V1 as the supply common voltage SVcom during other periods (in other words, during the remaining periods; in other words, during periods other than the first compensation period Ps1 and the second compensation period Ps2).

[0083] In the touch display device 110 according to an embodiment of the present disclosure, since the supply common voltage SVcom of the second voltage V2 lower than the first voltage Vl is applied to the touch electrode TE during the first compensation period Psl corresponding to the high level period Ph of the first gate voltage Vg1, the rising ripple component caused by the coupling of the rising edge Tr of the first gate voltage Vg1 to the third gate voltage Vg3 is compensated, and degradation such as bright lines is reduced or prevented.

[0084] In addition, since the supply common voltage SVcom of the third voltage V3 higher than the first voltage V1 is applied to the touch electrode TE during the second compensation period Ps2 corresponding to the high level period Ph of the nth gate voltage Vgn delayed by one horizontal period (1H), the falling ripple component caused by the coupling of the falling edge Tf of the (n-2)th gate voltage Vg(n-2) to the nth gate voltage Vgn is compensated, and degradation such as dark lines is reduced or prevented.

[0085] Although in an embodiment the gate voltage has a high level period corresponding to three horizontal periods (3H) and the high level period moves according to one horizontal period (1H), in another embodiment the gate voltage may have a high level period corresponding to three or more horizontal periods, and the high level period may move according to one or more horizontal periods. In another embodiment, since the common voltage is modulated to an opposite voltage value during a period in which the rising edge and the falling edge of the gate voltage do not overlap with the rising edge and the falling edge of another gate voltage, the ripple caused by the coupling of the gate voltage is compensated.

[0086] Therefore, in the touch display device according to the present disclosure, since the common voltage is modulated to have different values ​​in synchronization with the gate voltage of the gate line overlapping the rising and falling portions of the touch electrode, the ripple of the common voltage applied to the touch electrode is compensated and degradation such as bright lines is reduced or prevented.

[0087] In addition, since the common voltage decreases during the high level period of the gate voltage of the gate line that first overlaps the touch electrode, and increases during the period delayed by one horizontal period compared with the high level period of the gate voltage of the gate line that last overlaps the touch electrode, the average value of the common voltage remains constant, degradation such as bright lines is reduced or prevented, and the display quality is improved.

[0088] It will be apparent to those skilled in the art that various modifications and variations may 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 variations of the present disclosure as long as these modifications and variations are within the scope of the appended claims and their equivalents.

Claims

1. A touch display device, comprising: A touch display panel for displaying images and sensing touch; A plurality of touch electrodes are arranged on the touch display panel; A plurality of gate lines are arranged on the touch display panel; as well as a touch display driving unit, configured to supply a common voltage to the plurality of touch electrodes, wherein the common voltage has a first voltage before and after a first compensation period, and has a second voltage lower than the first voltage during the first compensation period, and the first compensation period corresponds to a high-level period of the gate voltage supplied to a gate line among the multiple gate lines that first overlaps with a touch electrode among the multiple touch electrodes.

2. The touch display device according to claim 1, wherein: The common voltage has the first voltage before and after a second compensation period, and has a third voltage higher than the first voltage during the second compensation period, wherein the second compensation period corresponds to a high-level period of the gate voltage supplied to a gate line among the multiple gate lines that last overlaps with one of the multiple touch electrodes.

3. The touch display device according to claim 2, further comprising a multiplexer, wherein the multiplexer is configured to: receiving the first voltage to the third voltage; selecting the first voltage before and after the first compensation period and before and after the second compensation period; selecting the second voltage during the first compensation period; as well as The third voltage is selected during the second compensation period.

4. The touch display device according to claim 2, wherein: The plurality of gate lines include first to n-th gate lines overlapping one of the plurality of touch electrodes, The gate voltage includes a first gate voltage to an nth gate voltage respectively applied to the first gate line to the nth gate line, wherein each of the first gate voltage to the nth gate voltage has a high level period of a high level voltage corresponding to three horizontal periods, and The high level periods from the first gate voltage to the nth gate voltage move according to one horizontal period.

5. The touch display device according to claim 4, wherein: The first compensation period includes a high level period of the first gate voltage.

6. The touch display device according to claim 4, wherein: The second compensation period includes a high level period of the nth gate voltage delayed by one horizontal period.

7. The touch display device according to claim 4, wherein: The rising edge of the fourth gate voltage to the (n-3)th gate voltage overlaps with the falling edge of one of the first gate voltage to the nth gate voltage, and The falling edge from the fourth gate voltage to the (n-3)th gate voltage overlaps with the rising edge of another gate voltage from the first gate voltage to the nth gate voltage.

8. The touch display device according to claim 1, wherein: The plurality of touch electrodes are divided into a plurality of blocks, and the plurality of gate lines overlap the plurality of touch electrodes.

9. A method for driving a touch display device, comprising: supplying a common voltage to a plurality of touch electrodes of a touch display device; supplying a gate voltage to a plurality of gate lines of the touch display device; as well as displaying an image in a touch display panel of the touch display device using the common voltage and the gate voltage, Wherein, supplying the common voltage comprises: supplying a first voltage as the common voltage before and after a first compensation period corresponding to a high level period of a gate voltage supplied to one of the plurality of gate lines that first overlaps one of the plurality of touch electrodes; and During the first compensation period, a second voltage lower than the first voltage is supplied as the common voltage.

10. The method according to claim 9, wherein: Supplying the common voltage comprises: supplying the first voltage as the common voltage before and after a second compensation period corresponding to a high level period of a gate voltage supplied to one of the plurality of gate lines that last overlaps one of the plurality of touch electrodes; and During the second compensation period, a third voltage higher than the first voltage is supplied as the common voltage.

11. The method according to claim 10, wherein: The plurality of gate lines include first to n-th gate lines overlapping one of the plurality of touch electrodes, The gate voltage includes a first gate voltage to an nth gate voltage respectively applied to the first gate line to the nth gate line, wherein each of the first gate voltage to the nth gate voltage has a high level period of a high level voltage corresponding to three horizontal periods, and The high level periods from the first gate voltage to the nth gate voltage move according to one horizontal period.

12. The method according to claim 11, wherein: The first compensation period includes a high level period of the first gate voltage.

13. The method according to claim 11, wherein: The second compensation period includes a high level period of the nth gate voltage delayed by one horizontal period.

14. The method according to claim 11, wherein: The rising edge of the fourth gate voltage to the (n-3)th gate voltage overlaps with the falling edge of one of the first gate voltage to the nth gate voltage, and The falling edge from the fourth gate voltage to the (n-3)th gate voltage overlaps with the rising edge of another gate voltage from the first gate voltage to the nth gate voltage.

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