Display Device having Touch Sensor and Driving Method of the same

Abstract

The present invention may provide a display device having a touch sensor comprising: a display panel including a touch electrode; a touch sensing line connected to the touch electrode; and a touch driving unit connected to the touch sensing line, wherein the touch driving unit applies a first touch driving signal to the touch electrode and applies a second touch driving signal having a different level from the first touch driving signal to the touch sensing line.

Description

Technology Field

[0001] The present invention relates to a display device having a touch sensor and a method for driving the same. Background Technology

[0002] As information technology advances, the market for display devices, which serve as a medium connecting users and information, is growing. Consequently, the use of display devices such as Light Emitting Display Devices (LEDs), Quantum Dot Display Devices (QDDs), and Liquid Crystal Display Devices (LCDs) is increasing.

[0003] The display devices described above include a display panel containing subpixels, a driving unit that outputs a driving signal for driving the display panel, and a power supply unit that generates power to be supplied to the display panel or the driving unit.

[0004] The above display devices can display an image when driving signals, such as scan signals and data signals, are supplied to subpixels formed on a display panel, causing selected subpixels to transmit light or emit light directly. In addition, the above display devices can receive user input in the form of touch based on a touch sensor and execute commands corresponding to the touch input. The problem to be solved

[0005] The present invention eliminates brightness reduction or frequency constraints when implementing a touch sensor within a display panel, improves the problem of reduced sensing sensitivity caused by parasitic capacitors in the touch sensing line to enhance sensing sensitivity, and minimizes the number of touch driving units by reducing the wiring required for touch sensing and the sensing circuits for driving and sensing it. means of solving the problem

[0006] The present invention may provide a display device having a touch sensor comprising: a display panel including a touch electrode; a touch sensing line connected to the touch electrode; and a touch driving unit connected to the touch sensing line, wherein the touch driving unit applies a first touch driving signal to the touch electrode and applies a second touch driving signal having a different level from the first touch driving signal to the touch sensing line.

[0007] The second touch driving signal may have a lower voltage level than the first touch driving signal.

[0008] The touch driving unit may include a touch driving transistor for applying the first touch driving signal to the touch sensing line and a touch sensing transistor for sensing the touch sensing line.

[0009] The above display panel may include a touch electrode transistor connected to the touch sensing line and the touch scan line to apply the first touch driving signal to the touch electrode.

[0010] The first touch driving signal can be applied to the touch electrode during the period when the touch driving transistor and the touch electrode transistor are turned on.

[0011] Sensing of the touch sensing line and the touch electrode can be performed during the period when the touch sensing transistor and the touch electrode transistor are turned on.

[0012] The touch electrode includes a plurality of touch electrodes, and the plurality of touch electrodes may be arranged in the form of separated divided electrodes corresponding to light-emitting regions included in a plurality of subpixels located on the display panel.

[0013] In another aspect, the present invention may provide a method for driving a display device having a touch sensor comprising a display panel including a touch electrode, a touch sensing line connected to the touch electrode, and a touch driving unit connected to the touch sensing line. The method for driving the display device may include a display driving step of displaying an image on the display panel; and a touch driving step of applying a first touch driving signal to the touch electrode, applying a second touch driving signal having a different level from the first touch driving signal to the touch sensing line, and sensing the touch electrode and the touch sensing line.

[0014] The display driving step and the touch driving step can be performed in parallel during a frame period.

[0015] The second touch driving signal may have a lower voltage level than the first touch driving signal. Effects of the invention

[0016] When implementing a touch sensor within a display panel, the present invention can eliminate brightness reduction or frequency constraints, and can improve sensing sensitivity by addressing the problem of reduced sensing sensitivity caused by parasitic capacitors present in the touch sensing line. In addition, when implementing a touch sensor within a display panel, the present invention has the effect of minimizing the number of touch driving units by reducing the wiring required for touch sensing and the sensing circuits for driving and sensing it. Brief explanation of the drawing

[0017] FIG. 1 is a block diagram schematically showing a light-emitting display device, and FIG. 2 is a configuration diagram schematically showing a subpixel shown in FIG. 1. FIGS. 3 to 5 are block diagrams for schematically explaining the configuration of a light-emitting display device having a touch sensor, and FIGS. 6 to 9 are cross-sectional views for schematically explaining a display panel having a touch sensor. FIGS. 10 and 11 are cross-sectional views schematically illustrating the structure of a display panel having a touch sensor and the change in capacitance depending on whether or not a touch occurs, and FIGS. 12 and 13 are plan views illustrating the structure of a touch electrode that performs the function of a touch sensor. FIG. 14 is a plan view showing the configuration of a display panel having a touch sensor and a touch driving unit, FIG. 15 is a plan view showing a part of FIG. 14 in more detail, FIG. 16 is a plan view with the pixel circuit removed from FIG. 15, and FIG. 17 to 19 are drawings for explaining the periodic operation states of the display panel having a touch sensor and the touch driving unit shown in FIG. 16. FIG. 20 is a timing diagram for briefly explaining the display driving and touch driving of a light-emitting display device having a touch sensor, FIG. 21 is a timing diagram for explaining the part related to touch driving in more detail, FIG. 22 to FIG. 25 are diagrams showing the operating state of the first to fourth sections of FIG. 21, and FIG. 26 and FIG. 27 are diagrams for explaining the change in capacitance according to the presence or absence of touch. Specific details for implementing the invention

[0018] The display device according to the present invention may be implemented as a television, video player, personal computer (PC), home theater, automotive electrical system, smartphone, etc., but is not limited thereto. The display device according to the present invention may be implemented as a light-emitting display device (LED), a quantum dot display device (QDD), a liquid crystal display device (LCD), etc. However, for convenience of explanation, a light-emitting display device that directly emits light based on an inorganic light-emitting diode or an organic light-emitting diode is used as an example below.

[0019] FIG. 1 is a block diagram schematically showing a light-emitting display device, and FIG. 2 is a configuration diagram schematically showing a subpixel shown in FIG. 1.

[0020] As illustrated in FIGS. 1 and 2, the light-emitting display device may include an image supply unit (110), a timing control unit (120), a scan driving unit (130), a data driving unit (140), a display panel (150), and a power supply unit (180), etc.

[0021] The video supply unit (or host system) (110) can output various driving signals along with video data signals supplied from the outside or video data signals stored in internal memory. The video supply unit (110) can supply the data signals and various driving signals to the timing control unit (120).

[0022] The timing control unit (120) can output a gate timing control signal (GDC) for controlling the operation timing of the scan drive unit (130), a data timing control signal (DDC) for controlling the operation timing of the data drive unit (140), and various synchronization signals (Vsync, a vertical synchronization signal, Hsync, a horizontal synchronization signal). The timing control unit (120) can supply a data signal (DATA) supplied from the image supply unit (110) to the data drive unit (140) along with the data timing control signal (DDC). The timing control unit (120) may be formed in the form of an IC (Integrated Circuit) and mounted on a printed circuit board, but is not limited thereto.

[0023] The scan driver (130) can output a gate signal (or scan signal) in response to a gate timing control signal (GDC) supplied from the timing control unit (120). The scan driver (130) can supply a gate signal (or scan signal) to subpixels included in the display panel (150) through gate lines (GL1~GLm). The scan driver (130) may be formed in the form of an IC or formed directly on the display panel (150) in a Gate In Panel manner, but is not limited thereto.

[0024] The data driver (140) can sample and latch a data signal (DATA) in response to a data timing control signal (DDC) supplied from the timing control unit (120), and convert the digital data signal into an analog data voltage based on a gamma reference voltage and output it. The data driver (140) can supply the data voltage to subpixels included in the display panel (150) through data lines (DL1~DLn). The data driver (140) may be formed in the form of an IC and mounted on the display panel (150) or mounted on a printed circuit board, but is not limited thereto.

[0025] The power supply unit (180) can generate a first power supply of high potential and a second power supply of low potential based on an external input voltage supplied from the outside, and output them through the first power line (EVDD) and the second power line (EVSS). The power supply unit (180) can generate and output not only the first power supply and the second power supply, but also voltages required for driving the scan drive unit (130) (e.g., gate voltage including gate high voltage and gate low voltage) or voltages required for driving the data drive unit (140) (drain voltage including drain voltage and half-drain voltage), etc.

[0026] The display panel (150) can display an image in response to a driving signal including a gate signal (or scan signal) and a data voltage, and a first power supply and a second power supply, etc. The subpixels of the display panel (150) can directly emit light. The display panel (150) can be manufactured based on a substrate or film having rigidity or flexibility, such as glass, silicon, or polyimide. The subpixels emitting light can be composed of pixels including red, green, and blue, or pixels including red, green, blue, and white.

[0027] For example, one subpixel (SP) may include a pixel circuit connected to a first data line (DL1), a first gate line (GL1), a first power line (EVDD), and a second power line (EVSS). The pixel circuit may include a transistor circuit such as a switching transistor, a driving transistor, and a capacitor, and an organic light-emitting diode, etc.

[0028] The subpixels (SPs) used in light-emitting display devices directly emit light, so their circuit configuration is complex. Furthermore, there are various compensation circuits to compensate for the degradation of not only the light-emitting organic light-emitting diodes (OLEDs) but also the driving transistors that supply driving current to the OLEDs. Therefore, please note that the subpixels (SPs) are illustrated in a simplified block form.

[0029] Meanwhile, in the above description, the timing control unit (120), scan driving unit (130), and data driving unit (140) were described as being separate components. However, depending on the implementation method of the light-emitting display device, one or more of the timing control unit (120), scan driving unit (130), and data driving unit (140) may be integrated into a single IC.

[0030] FIGS. 3 to 5 are block diagrams for schematically explaining the configuration of a light-emitting display device having a touch sensor, and FIGS. 6 to 9 are cross-sectional views for schematically explaining a display panel having a touch sensor.

[0031] As illustrated in FIGS. 3 to 5, a display panel (150; PNL) included in a light-emitting display device for displaying images may have a touch sensor (155; TSP) capable of receiving user input in a touch manner. The touch sensor (155) may have touch electrodes for detecting the presence or absence of touch and location information regarding the display panel (150).

[0032] The display panel (150) can be driven by a data driving unit (140; DIC), and the touch sensor (155) can be driven by a touch driving unit (145; ROIC). The display panel (150) and the touch sensor (155) can be formed as separate components as shown in FIG. 3, and can also be integrated into a single panel as shown in FIG. 4 and FIG. 5.

[0033] When the display panel (150) and the touch sensor (155) are integrated into a single panel (PNL+TSP), the data driving unit (140) and the touch driving unit (145) may be provided to exist independently as shown in FIG. 4, or the touch driving unit (ROIC) may be provided to be included inside the data driving unit (140) as shown in FIG. 5. Hereinafter, a structure in which the display panel (150) and the touch sensor (155) are integrated into a single panel (PNL+TSP) is defined as a display panel (150) having a touch sensor.

[0034] As illustrated in FIGS. 6 to 9, a display panel (150) having a touch sensor may include a first film (150a), a pixel circuit (TFT + OLED) composed of a transistor circuit (TFT) and an organic light-emitting diode (OLED), a touch electrode (TE) that performs the function of a touch sensor, and a second film (150b). One of the first film (150a) and the second film (150b) may be selected as an encapsulation layer (organic-inorganic composite layer).

[0035] As illustrated in FIGS. 6 and 7, the pixel circuit (TFT + OLED) can emit light in the direction of the second film (150b). The touch electrode (TE) can be located between the second film (150b) and the pixel circuit (TFT + OLED) as in FIG. 6, or between the first film (150a) and the pixel circuit (TFT + OLED) as in FIG. 7.

[0036] As illustrated in FIGS. 8 and 9, the pixel circuit (TFT + OLED) can emit light in the direction of the first film (150a). The touch electrode (TE) can be located between the first film (150a) and the pixel circuit (TFT + OLED) as in FIG. 8, or between the second film (150b) and the pixel circuit (TFT + OLED) as in FIG. 9.

[0037] As can be seen from the examples in FIGS. 6 to 9, the touch electrode (TE) may be placed close to the film constituting the display screen, or it may not be placed close to it. The reason the position where the touch electrode (TE) is placed can be freely varied in this way is that the display panel (150) having the touch sensor is formed in the form of a thin film, so a change in capacitance due to touch can be easily obtained.

[0038] FIGS. 10 and 11 are cross-sectional views schematically illustrating the structure of a display panel having a touch sensor and the change in capacitance depending on whether or not a touch occurs, and FIGS. 12 and 13 are plan views illustrating the structure of a touch electrode that performs the function of a touch sensor.

[0039] As illustrated in FIG. 10, an organic light-emitting diode (OLED) comprising a cathode electrode (CAT), an organic layer (EML) including a light-emitting layer, and an anode electrode (ANO) may be located on a first film (150a). A color filter layer (CFR, CFG) may be located on an overcoat layer (OC) covering the organic light-emitting diode (OLED). The color filter layer (CFR, CFG) is a component that converts light emitted from the organic light-emitting diode (OLED) into red, green, etc., and may be omitted if the organic light-emitting diode (OLED) emits red, green, etc., rather than white.

[0040] Touch electrodes (TE1, TE2) may be located on an insulating layer (INS1) covering a color filter layer (CFR, CFG). Touch electrodes (TE1, TE2) may be divided into multiple parts and located corresponding to an anode electrode (ANO). A touch sensing line (TSL) may be located between the first touch electrode (TE1) and the second touch electrode (TE2). The touch sensing line (TSL) may be connected to the first touch electrode (TE1) or to the second touch electrode (TE2). A second film (150b), an adhesive layer (ADH), and a cover substrate (151) may be located on the touch electrodes (TE1, TE2) and the touch sensing line (TSL). The cover substrate (151) may be selected as glass.

[0041] The touch electrodes (TE1, TE2) can be selected from a transparent electrode material (e.g., ITO). On the other hand, long signal lines such as touch sensing lines (TSL) can be selected from low-resistance materials, such as a separate metal layer or a data metal layer for forming data lines. The insulating layer (INS1) insulating the touch electrodes (TE1, TE2) can be selected from silicon oxide (SiO2), silicon nitride (SiN), transparent organic insulating film, etc. In addition, one touch electrode may have a standard size of 5mm × 5mm, but is not limited thereto.

[0042] As illustrated in FIG. 11, when a finger touches the cover substrate (151) where the first touch electrode (TE1) is located, capacitance may be generated between the first touch electrode (TE1) and the cover substrate (151). This change in capacitance may also appear on the electrodes located below the first touch electrode (TE1). Unlike the first touch electrode (TE1), the cover substrate (151) where the second touch electrode (TE2) is located is not touched by a finger, so it can be seen that no capacitance is generated between the second touch electrode (TE2) and the cover substrate (151).

[0043] As such, a display panel having a touch sensor can detect the presence or absence of touch and location information using a mechanism that can induce a change in capacitance or a user's finger. Meanwhile, in FIG. 10, touch electrodes (TE1, TE2) and touch sensing lines (TSL) are formed on the inner surface of the second film (150b) as an example, but the present invention is not limited thereto.

[0044] As illustrated in FIG. 12, the first touch electrode (TE1) may be composed of a plurality of touch electrodes (TE1a to TE1f). The plurality of touch electrodes (TE1a to TE1f) may be separated and arranged in the form of divided electrodes so as to be positioned corresponding to the light-emitting regions (EMA) included in the plurality of subpixels (SP1 to SP6). Additionally, the plurality of touch electrodes (TE1a to TE1f) may be electrically connected by bridge electrodes (TEB) provided between them. That is, the touch electrodes (TE1a to TE1f) included in the first touch electrode (TE1) and the subpixels (SP1 to SP6) may have a 1:1 relationship.

[0045] In FIG. 12, to explain the arrangement structure of multiple touch electrodes (TE1a to TE1f), an example was given in which the size (area) is smaller than the light-emitting region (EMA) included in multiple subpixels (SP1 to SP6). However, the size (area) of the multiple touch electrodes (TE1a to TE1f) may be the same as or larger than the size (area) of the light-emitting region (EMA) included in multiple subpixels (SP1 to SP6).

[0046] As illustrated in FIG. 13, the first touch electrode (TE1) can be formed in the form of a single face electrode capable of widely covering the light-emitting region (EMA) included in a plurality of subpixels (SP1 to SP6) and the surrounding region. That is, the first touch electrode (TE1) and the subpixels (SP1 to SP6) can have a 1:N relationship (N is an integer greater than or equal to 2).

[0047] FIG. 14 is a plan view showing the configuration of a display panel having a touch sensor and a touch driving unit, FIG. 15 is a plan view showing a part of FIG. 14 in more detail, FIG. 16 is a plan view with the pixel circuit removed from FIG. 15, and FIG. 17 to 19 are drawings for explaining the periodic operation states of the display panel having a touch sensor and the touch driving unit shown in FIG. 16.

[0048] As illustrated in FIG. 14, touch electrodes (TE) may be arranged in a plurality along a first direction (vertical direction) on a display panel (150) having a touch sensor. The plurality of arranged touch electrodes (TE) may be electrically connected to a touch driving unit (145) by a touch sensing line. For example, touch electrodes (TE, 1 to 160) arranged in the first line may be electrically connected to the first sensing circuit of the touch driving unit (145) by a first touch sensing line (TSL1). According to this method, touch electrodes (TE, 1 to 160) arranged in the Nth line are electrically connected to the Nth sensing circuit of the touch driving unit (145) by a Nth touch sensing line (TSLn).

[0049] A display device having a touch sensor illustrated in FIG. 14 may include n touch sensing lines (TSL1 to TSLn), m touch scan lines (TGL1 to TGLm), and TFTs connected thereto to drive m × n touch electrodes (TE). When sensing the presence or absence of touch based on the n touch sensing lines (TSL1 to TSLn), m touch scan lines (TGL1 to TGLm), and TFTs connected thereto, only m pieces of information can be processed in a specific sensing interval. Therefore, when sensing the presence or absence of touch, only n sensing circuits are required, thereby minimizing the increase in the number of touch driving units.

[0050] A display device having a touch sensor illustrated in FIG. 14 can eliminate brightness reduction or frequency constraints based on n touch sensing lines (TSL1 to TSLn), m touch scan lines (TGL1 to TGLm), and TFTs connected thereto. In addition, the display device having a touch sensor illustrated in FIG. 14 can resolve the problem of reduced sensing sensitivity caused by parasitic capacitors present in the touch sensing lines, which is explained as follows.

[0051] As illustrated in FIGS. 15 and 16, the touch driving unit (145) may include a driving signal generating unit (DRV), a plurality of touch driving transistors (T1, T4), a plurality of touch sensing transistors (T2, T5), a plurality of sensing circuits (SEN1, SEN2), etc.

[0052] The driving signal generation unit (DRV) can generate a touch driving signal. Multiple touch driving transistors (T1, T4) can activate the output to transmit the touch driving signal generated from the driving signal generation unit (DRV) to multiple touch sensing lines (TSL1, TSL2). Multiple touch sensing transistors (T2, T5) can activate sensing for multiple touch sensing lines (TSL1, TSL2). Multiple sensing circuits (SEN1, SEN2) can integrate the sensing value input through the multiple touch sensing lines (TSL1, TSL2) and output it. Each of the multiple sensing circuits (SEN1, SEN2) may include an integrator (INT), etc.

[0053] A display panel (150) having a touch sensor may include a plurality of touch sensing lines (TSL1, TSL2), a plurality of touch electrodes (TE1, TE2), a plurality of touch electrode transistors (T3, T6), a plurality of subpixels (SP), a plurality of touch scan lines (TGL1), etc.

[0054] A plurality of touch sensing lines (TSL1, TSL2) can be arranged in a first direction and can be connected separately to a connection point where one electrode of a plurality of touch driving transistors (T1, T4) and one electrode of a plurality of touch sensing transistors (T2, T5) are commonly connected.

[0055] A plurality of touch scan lines (TGL1) can be arranged in a second direction (horizontal direction) and can be connected to use a touch scan signal output from a touch driving unit (145) or a scan signal output from a scan driving unit that drives a display panel (150) having a touch sensor as a touch scan signal.

[0056] A plurality of touch electrode transistors (T3, T6) can be placed at the intersection of a plurality of touch sensing lines (TSL1, TSL2) and a plurality of touch scan lines (TGL1), and can be turned on in response to a touch scan signal so that a plurality of touch sensing lines (TSL1, TSL2) and a plurality of touch electrodes (TE1, TE2) are electrically connected.

[0057] A plurality of touch electrodes (TE1, TE2) can be arranged in a block shape and connected to a single touch electrode transistor to operate as a single touch sensor. A single touch electrode can be arranged in a divided electrode form including a plurality of subpixels (SP) or in a face electrode form.

[0058] As illustrated in FIG. 17, during the first touch driving period, a plurality of touch driving transistors (T1, T4) and a plurality of touch electrode transistors (T3, T6) may be in a turned-on state. At this time, the driving signal generating unit (DRV) may apply a first touch driving signal through a plurality of touch sensing lines (TSL1, TSL2) and a plurality of touch electrodes (TE1, TE2).

[0059] As illustrated in FIG. 18, during the second touch driving period, a plurality of touch driving transistors (T1, T4) may be in a turned-on state, and a plurality of touch electrode transistors (T3, T6) may be in a turned-off state. At this time, the driving signal generating unit (DRV) may apply a second touch driving signal through a plurality of touch sensing lines (TSL1, TSL2).

[0060] As illustrated in FIG. 19, during the touch sensing period, a plurality of touch sensing transistors (T2, T5) and a plurality of touch electrode transistors (T3, T6) may be in a turned-on state, and a plurality of touch driving transistors (T1, T4) may be in a turned-off state. At this time, a plurality of sensing circuits (SEN1, SEN2) may sense a plurality of touch sensing lines (TSL1, TSL2).

[0061] FIG. 20 is a timing diagram for briefly explaining the display driving and touch driving of a light-emitting display device having a touch sensor, FIG. 21 is a timing diagram for explaining the part related to touch driving in more detail, FIG. 22 to FIG. 25 are diagrams showing the operating state of the first to fourth sections of FIG. 21, and FIG. 26 and FIG. 27 are diagrams for explaining the change in capacitance according to the presence or absence of touch.

[0062] As illustrated in FIG. 20, a light-emitting display device having a touch sensor can operate based on a driving frequency of 120 Hz during a frame period. The light-emitting display device having a touch sensor can perform touch driving (sensing) in parallel with display driving (displaying) during a frame period. As a result, brightness reduction or frequency constraints can be eliminated.

[0063] Displaying is illustrated as a block drive (multiple line drive) in the form of lines 1 through 15 (1 through 15 rows) and lines 16 through 30 (1 through 15 rows), and touch driving (sensing) is illustrated as a single drive (single line drive) in the form of lines 1 through 2 (1 row) and lines 2 through 2, but is not limited thereto. Additionally, displaying and touch driving are illustrated as sequentially, but they may be performed in reverse order or randomly.

[0064] As shown in FIG. 21, the touch drive may include a first period (P1) for applying a first touch drive signal, a second period (P2) for applying a second touch drive signal, a third period (P3) for maintaining the applied signal, and a fourth period (P4) for sensing whether there is a change in the touch drive signal.

[0065] As shown in FIGS. 22 to 24, the first sensing circuit (SEN1) may include a capacitor (Cs), an amplifier (AMP), and an integrator (INT). The first sensing circuit (SEN1) is illustrated as being located at each sensing line as an example, but is not limited thereto.

[0066] In FIG. 21, DRV is a touch driving signal, T1 is a first control signal for controlling the first touch driving transistor (T1), T2 is a second control signal for controlling the second touch driving transistor (T2), and T3 is a first touch scan signal for controlling the first touch electrode transistor (T3). Also in FIG. 21, VSL is a voltage charged in the first touch sensing line (TSL1), REF is a reference voltage applied to the amplifier, VAMP is the output voltage of the amplifier, VINIT is a voltage charged in the capacitor (Cs), and VOUT is the output voltage of the integrator (INT).

[0067] As illustrated in FIGS. 21 and 22, during the first period (P1), the first touch driving transistor (T1) and the first touch electrode transistor (T3) may be in a turned-on state, and the driving signal generating unit (DRV) may apply a first level first touch driving signal (DRV_L1) through the first touch sensing line (TSL1) and the first touch electrode (TE1).

[0068] As illustrated in FIGS. 21 and 23, during the second period (P2), the first touch driving transistor (T1) may be in a turned-on state and the first touch electrode transistor (T3) may be in a turned-off state, and the driving signal generation unit (DRV) may apply a second level second touch driving signal (DRV_L2) through the first touch sensing line (TSL1). The second level second touch driving signal (DRV_L2) may be selected at a lower voltage level than the first level first touch driving signal (DRV_L1) applied earlier. By using a differential input method that creates a voltage difference between two touch driving signals, such as the first level first touch driving signal (DRV_L1) and the second level second touch driving signal (DRV_L2), the problem of reduced sensing sensitivity caused by parasitic capacitors present in the touch sensing line can be improved, thereby enhancing the sensing sensitivity.

[0069] As illustrated in FIGS. 21 and 24, during the third period (P3), the first touch driving transistor (T1), the second touch sensing transistor (T2), and the first touch electrode transistor (T3) may be in a turned-off state. The third period (P3) corresponds to a period for maintaining a previously applied signal for stable operation, but this may be omitted. Meanwhile, if a touch occurs by a user during the third period (P3), a finger voltage (C_finger) may be charged to the first touch electrode (TE1).

[0070] As illustrated in FIGS. 21 and 25, during the fourth period (P4), the second touch sensing transistor (T2) and the first touch electrode transistor (T3) may be in a turned-on state, the first touch driving transistor (T1) may be in a turned-off state, and the first sensing circuit (SEN1) may sense the first touch sensing line (TSL1).

[0071] By the preceding operation, the first touch electrode (TE1) may be in a state where the electrode voltage (C_touch electrode) by the first level first touch driving signal (DRV_L1) and the finger voltage (C_finger) by the user are charged. Also, the first touch sensing line (TSL1) may be in a state where the line voltage (C_sensing line) by the second level second touch driving signal (DRV_L2) is charged.

[0072] As shown in FIG. 26, after the touch drive is completed, a situation may occur where a touch occurs ([Touch: O]) on the first touch electrode (TE1) while no touch occurs ([Touch: X]) on the J touch electrode (TEj).

[0073] In the case of the first touch sensing line (TSL1) where a touch occurs ([Touch: O]) and the J touch sensing line (TSLj) where no touch occurs ([Touch: X]), the line voltage (C_sensing line) due to touch driving = 200pF may be charged equally.

[0074] And the J-touch electrode (TEj) where no touch occurs ([Touch: X]) may be charged with only the electrode voltage (C_touch electrode) = 60pF due to touch driving. However, the 1-touch electrode (TE1) where a touch occurs ([Touch: O]) may be charged with the electrode voltage (C_touch electrode) = 60pF due to touch driving, along with the finger voltage (C_finger) = 1pF due to contact with the user's finger.

[0075] As such, a voltage difference (ΔV) based on the presence or absence of touch can be formed between the first touch electrode (TEj) where no touch occurs ([Touch: X]) and the first touch electrode (TE1) where a touch occurs ([Touch: O]), as shown in FIG. 27. This voltage difference (ΔV) can be used as raw touch data to determine whether or not a touch occurs. Accordingly, by performing touch driving in the flow shown in FIG. 22 to FIG. 25, the presence or absence of touch and location information regarding the display panel can be detected.

[0076] In summary, when implementing a touch sensor within a display panel, the present invention can eliminate brightness reduction or frequency constraints, and can improve sensing sensitivity by addressing the problem of reduced sensing sensitivity caused by parasitic capacitors present in the touch sensing line. Furthermore, when implementing a touch sensor within a display panel, the present invention has the effect of minimizing the number of touch driving units by reducing the wiring required for touch sensing and the sensing circuits for driving and sensing it. Explanation of the symbols

[0077] 145: Touch actuator 150: Display panel DRV: Driving signal generation unit T1, T4: Multiple touch driving transistors SEN1, SEN2: Multiple sensing circuits TGL1: Multiple touch scan lines TE1, TE2: Multiple touch electrodes TSL1, TSL2: Multiple touch sensing lines T2, T5: Multiple touch-sensing transistors T3, T6: Multiple touch electrode transistors

Claims

Claim 1 A display device comprising: a display panel including a touch electrode; a touch sensing line connected to the touch electrode; and a touch driving unit connected to the touch sensing line, wherein the touch driving unit has a touch sensor that applies a first touch driving signal to the touch electrode and applies a second touch driving signal having a different level from the first touch driving signal to the touch sensing line, wherein the touch driving unit includes a touch driving transistor for applying the first touch driving signal to the touch sensing line and a touch sensing transistor for sensing the touch sensing line, wherein the display panel includes a touch electrode transistor connected to the touch sensing line and a touch scan line to apply the first touch driving signal to the touch electrode, and wherein the first touch driving signal is applied to the touch electrode during the period in which the touch driving transistor and the touch electrode transistor are turned on. Claim 2 In claim 1, the second touch driving signal is a display device having a touch sensor having a voltage level lower than the first touch driving signal. Claim 3 delete Claim 4 delete Claim 5 delete Claim 6 A display device having a touch sensor in which sensing of the touch sensing line and the touch electrode is performed during the period when the touch sensing transistor and the touch electrode transistor are turned on in claim 1. Claim 7 A display device according to claim 1, wherein the touch electrode comprises a plurality of touch electrodes, and the plurality of touch electrodes are arranged in the form of separated divided electrodes corresponding to light-emitting regions included in a plurality of subpixels located on the display panel. Claim 8 A method for driving a display device comprising: a display panel including a touch electrode; a touch sensing line connected to the touch electrode; and a touch driving unit connected to the touch sensing line, wherein the touch driving unit includes a touch driving transistor for applying a first touch driving signal to the touch sensing line and a touch sensing transistor for sensing the touch sensing line, and wherein the display panel includes a touch electrode transistor connected to the touch sensing line and a touch scanning line for applying a first touch driving signal to the touch electrode, the method comprising: a display driving step of displaying an image on the display panel; and a touch driving step of applying the first touch driving signal to the touch electrode, applying a second touch driving signal having a different level from the first touch driving signal to the touch sensing line, and sensing the touch electrode and the touch sensing line. A method for driving a display device having a touch sensor, comprising: a touch sensing step in which the first touch driving signal is applied to the touch electrode during the period in which the touch driving transistor and the touch electrode transistor are turned on. Claim 9 In claim 8, the method of driving a display device having a touch sensor, wherein the display driving step and the touch driving step are performed in parallel during a frame period. Claim 10 In claim 8, the driving method of a display device having a touch sensor having a voltage level lower than the first touch driving signal, wherein the second touch driving signal is a second touch driving signal.

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