KR20130065348A - Touch sensor integrated type display and method for improving touch performance thereof - Google Patents

Abstract

PURPOSE: A display device with touch sensors and a touch performance improving method thereof are provided to avoid noise by changing touch driving timing when specific data patterns are inputted. CONSTITUTION: Video data is inputted(S10). The input video data is compared with a predetermined specific data pattern(S20). If the input video data and the specific data pattern are identical, touch driving timing is changed from an initial default value to a different value(S40). If the input video data and the specific data pattern are not identical, the touch driving timing is maintained with the initial default value(S50). [Reference numerals] (AA) Start; (BB) End; (S10) Input video data; (S20) Compare the video data with the predetermined specific data pattern; (S30) Video data = specific data pattern?; (S40) Change touch driving timing; (S50) Maintain touch driving timing

Description

TOUCH SENSOR INTEGRATED TYPE DISPLAY AND METHOD FOR IMPROVING TOUCH PERFORMANCE THEREOF}

The present invention relates to a display device having a touch sensor and a method of improving touch performance thereof.

User input means has been replaced with a touch screen in a button-type switch in accordance with the trend of lightening and slimming of household appliances and portable information devices. The touch screen refers to a screen that directly touches the screen without the need for another input device, and the use of the touch screen in the overall IT product is expanding as it is used in the handphone market.

The touch screen applied to the display device includes a plurality of touch sensors. The touch recognition method is known as a resistive type, a capacitive type, and an electro magnetic type. Among them, a touched part is detected by sensing a position where a capacitance change has occurred. Capacitive method is widely used.

As shown in FIG. 1, a plurality of driving electrode lines Tx (hereinafter, referred to as 'Tx electrode lines') and a plurality of receiving electrode lines Rx (hereinafter, And touch sensors formed at intersections of the Tx electrode lines and the Rx electrode lines. The touch sensor is implemented with a mutual capacitor (Cm). When the finger approaches the electrodes Tx and Rx of the mutual capacitance Cm, the electric field between the electrodes Tx and Rx is cut off, thereby reducing the charge amount of the mutual capacitance Cm. The capacitive touch sensors sense a change in the charge amount of the mutual capacitance Cm before and after the touch. The capacitive touch sensors may be bonded to the display panel of the display device.

A plurality of data lines to which a data voltage is applied, a common voltage Vcom, and a common electrode line coupled to the data lines through parasitic capacitance are formed on the display panel of the display device. The common electrode line is coupled to the Tx electrode line through the parasitic capacitance Ctx as shown in FIG. 1, and also coupled to the Rx electrode line through the parasitic capacitance Crx. In FIG. 1, "Rtx" means line resistance of the Tx electrode line, "Rrx" means line resistance of the Rx electrode line, and "ROIC" means lead-out integrated circuit, respectively.

The potential of the data lines changes every time the data voltage changes. The change in the potential of these data lines affects the potential of the common electrode line to cause common voltage noise (Vcom noise). The common voltage noise refers to ripple that is mixed in the common voltage Vcom due to the potential variation of the data lines.

The magnitude of the common voltage noise mainly depends on the data pattern for image display. In general, many specific data patterns (hereinafter, referred to as "worst patterns") that cause common voltage noise are known. For example, in the worst pattern, a 1-dot vertical line pattern in which polarity is inverted in units of 2 dots vertically and 1 dot in horizontal (hereinafter, referred to as 'V2H1') as shown in FIG. 2, and 1 whose polarity is inverted in units of V2H1 as shown in FIG. 3. A dot check pattern and a modified two dot check pattern in which polarity is inverted in V2H1 units as shown in FIG. 4 are included.

These worst patterns repeat the full white gradation (maximum gradation that can be expressed, for example, 255 gradations of 0 to 255 gradations) and the full black gradation (minimum gradation that can be expressed, for example 0 to gradations of 0 to 255 gradations) in predetermined units. In the full white gradation, the potential difference between the data voltage and the common voltage Vcom becomes maximum, and in the full black gradation, the potential difference between the data voltage and the common voltage Vcom becomes minimum. The polarity of the data is determined by the height of the data voltage based on the common voltage Vcom. When the data voltage is higher than the common voltage Vcom, the polarity of the data is determined to be positive (+). On the contrary, when the data voltage is lower than the common voltage Vcom, the polarity of the data is determined to be negative.

In the one-dot vertical line pattern of FIG. 2, the full white gray and the full black gray are repeated in units of one vertical line. In the one-dot vertical line pattern of FIG. 2, the data voltage of the N vertical line is between a level higher than the common voltage Vcom and a level lower than the common voltage Vcom at intervals of two horizontal periods according to a "++-" polar pattern. Swing at, but maintain the common voltage (Vcom) and the maximum potential difference. The data voltage of the N + 1 vertical line swings between a level lower than the common voltage (Vcom) and a level higher than the common voltage (Vcom) at intervals of two horizontal periods according to a "-++" polar pattern. Maintain a minimum potential difference with the common voltage Vcom. When the data voltage fluctuation waveforms of the N vertical lines and the data voltage fluctuation waveforms of the N + 1 vertical lines are canceled with each other based on the common voltage Vcom, the average of the data voltages applied to these vertical lines N and N + 1 is obtained. The potential variation is obtained. The average potential of the data voltage changes significantly with respect to the common voltage Vcom every two horizontal periods. As a result, ripple occurs in the common voltage Vcom every two horizontal periods.

The one dot check pattern of FIG. 3 repeats the full white gray level and the full black gray level in units of one dot in the vertical and horizontal directions. In the one dot check pattern of FIG. 3, the data voltage of the N vertical line swings on the basis of the common voltage Vcom every two horizontal periods according to the "++-" polar pattern, but the potential difference from the common voltage Vcom is changed. 1 Repeat the horizontal period in order of "MIN, MAX, MIN, MAX". The data voltage of the N + 1 vertical line is swinged based on the common voltage Vcom every two horizontal periods according to the "-++" polarity pattern, and the potential difference from the common voltage Vcom is changed by one horizontal period ". Repeat "Max, Min, Max, Min" in that order. When the data voltage fluctuation waveforms of the N vertical lines and the data voltage fluctuation waveforms of the N + 1 vertical lines are canceled with each other based on the common voltage Vcom, the average of the data voltages applied to these vertical lines N and N + 1 is obtained. The potential variation is obtained. The average potential of the data voltage changes significantly with respect to the common voltage Vcom every two horizontal periods. As a result, ripple occurs in the common voltage Vcom every two horizontal periods.

The modified two-dot check pattern of FIG. 4 repeats the full white gradation and the full black gradation in units of two dots in the vertical direction except for the first horizontal line, and repeats the full white gradation and the full black gradation in units of one dot in the horizontal direction. . In the modified two-dot check pattern of FIG. 4, the data voltage of the N vertical line swings on the basis of the common voltage Vcom every two horizontal periods according to the "++-" polar pattern, but with a potential difference from the common voltage Vcom. Repeat 1 horizontal period in order of "Max, Min, Min, Max". The data voltage of the N + 1 vertical line is swinged based on the common voltage Vcom every two horizontal periods according to the "-++" polarity pattern, and the potential difference from the common voltage Vcom is changed by one horizontal period ". Repeat "MIN, MAX, MAX, MIN". When the data voltage fluctuation waveforms of the N vertical lines and the data voltage fluctuation waveforms of the N + 1 vertical lines are canceled with each other based on the common voltage Vcom, the average of the data voltages applied to these vertical lines N and N + 1 is obtained. The potential variation is obtained. The average potential of the data voltage changes significantly with respect to the common voltage Vcom every one horizontal period. As a result, a ripple occurs in the common voltage Vcom every one horizontal period.

As such, when the worst patterns are displayed on the display panel, the common voltage noise is very prominent. The prior art generates a touch driving pulse (Tx pulse) after the predetermined default time T1 elapses as shown in FIG. 5 without considering the worst patterns, thereby driving the touch sensors.

When the touch sensors are driven in the period in which the common voltage noise is generated by the worst patterns, the common voltage noise is mixed into the touch signal through the parasitic capacitances Ctx and Crx shown in FIG. As the common voltage noise increases, distortion of the sensing value obtained from the touch screen becomes more severe, and when the distortion of the sensing value becomes more severe, an unwanted touch result may be obtained as shown in FIG. 6.

Accordingly, an object of the present invention is to provide a display device having a touch sensor and a method of improving touch performance thereof, which can increase touch performance regardless of generation of common voltage noise due to specific data patterns.

In order to achieve the above object, a display device having a touch sensor according to an embodiment of the present invention includes a display panel having a touch screen formed with touch sensors; A Tx driving circuit supplying a touch driving pulse to the Tx lines of the touch screen; An Rx driving circuit for sampling the sensing voltages of the touch sensors received through the Rx lines of the touch screen by supplying the touch driving pulses; A specific pattern detection circuit configured to detect whether the video data is the same as the specific data pattern by comparing the video data to be input to the display panel with a predetermined specific data pattern; And a touch controller configured to differently control the timing of generation of the touch driving pulse according to the detection result. The specific data pattern is selected as at least one worst pattern that causes common voltage noise to be mixed with the sensing voltage.

According to an exemplary embodiment of the present invention, a display panel having a touch screen on which touch sensors are formed, a Tx driving circuit supplying touch driving pulses to Tx lines of the touch screen, and Rx of the touch screen by supplying the touch driving pulses In a method of improving touch performance of a display device having an Rx driving circuit for sampling the sensing voltages of the touch sensors received through lines, the video data is compared with a predetermined data pattern by comparing the video data to be input to the display panel. Detecting whether or not the same as the specific data pattern; And controlling the timing of generation of the touch driving pulse differently according to the detection result. The specific data pattern is selected as at least one worst pattern that causes common voltage noise to be mixed with the sensing voltage.

The present invention changes touch driving timing at the time of inputting specific data patterns causing common voltage noise and avoids the noise, thereby greatly improving touch performance and touch reliability regardless of occurrence of common voltage noise due to specific data patterns. It can increase.

1 shows an equivalent circuit of a touch sensor.
2 through 4 show various examples of the worst pattern.
FIG. 5 is a diagram illustrating that a touch sensor is driven in a period in which common voltage noise is generated by a worst pattern; FIG.
6 illustrates an example of a distorted touch result due to mixing of a common voltage.
7 illustrates a display device according to an exemplary embodiment of the present invention.
8 through 10 illustrate various embodiments of a touch screen and a display panel.
11 is a view showing a specific pattern detection circuit shown in FIG.
12 is a diagram illustrating an example in which a touch driving timing is changed in response to an input of a worst pattern.
FIG. 13 is a view showing an experiment result in which touch performance is increased by changing the touch driving timing. FIG.
14 illustrates a method of improving touch performance of a display device according to an exemplary embodiment of the present invention.

Hereinafter, exemplary embodiments of the present invention will be described in detail with reference to FIGS. 7 to 14.

7 is a block diagram illustrating a display device according to an exemplary embodiment of the present invention. 8 to 10 are views illustrating various embodiments of a touch screen and a display panel.

Referring to FIG. 7, a display device according to an exemplary embodiment may include a display panel DIS, a display driving circuit 202 and 204, a timing controller 400, a specific pattern detection circuit 402, a touch screen TSP, and a touch. And screen driving circuits 302 and 304, touch controller 306, and the like.

The display device of the present invention is a liquid crystal display (LCD), a field emission display (FED), a plasma display panel (PDP), an organic light emitting diode display (Organic Light Emitting Display) , OLED), and electrophoretic display devices (Electrophoresis, EPD) can be implemented based on a flat panel display device. In the following embodiments, the display device is described centering on the liquid crystal display element, but it should be noted that the display device of the present invention is not limited to the liquid crystal display element.

In the display panel DIS, a liquid crystal layer is formed between two substrates. The lower substrate of the display panel DIS includes a plurality of data lines D1 to Dm and m are natural numbers, a plurality of gate lines G1 to Gn and n are natural numbers intersecting the data lines D1 to Dm. A plurality of TFTs formed at intersections of the data lines D1 to Dm and the gate lines G1 to Gn, a plurality of pixel electrodes for charging data voltages to liquid crystal cells, and pixels Storage capacitors and the like are respectively connected to the electrodes to maintain the voltage of the liquid crystal cell.

The pixels of the display panel DIS are formed in a pixel region defined by the data lines D1 to Dm and the gate lines G1 to Gn and arranged in a matrix form. The liquid crystal cell of each pixel is driven by an electric field applied according to the voltage difference between the data voltage applied to the pixel electrode and the common voltage applied to the common electrode to adjust the transmission amount of incident light. The TFTs are turned on in response to gate pulses from the gate lines G1 to Gn to supply a voltage from the data lines D1 to Dm to the pixel electrodes of the liquid crystal cell.

The upper substrate of the display panel DIS may include a black matrix, a color filter, and the like. The lower substrate of the display panel DIS may be implemented with a COT (Color Filter On TFT) structure. In this case, the black matrix and the color filter can be formed on the lower substrate of the display panel DIS.

A polarizing plate is attached to each of the upper and lower substrates of the display panel DIS, and an alignment layer for setting the pretilt angle of the liquid crystal is formed on an inner surface of the display panel DIS. A column spacer for maintaining a cell gap of the liquid crystal cell is formed between the upper substrate and the lower substrate of the display panel DIS.

A backlight unit may be disposed on the back surface of the display panel DIS. The backlight unit is implemented as an edge type or direct type backlight unit to emit light to the display panel DIS. The display panel DIS may be implemented in any known liquid crystal mode such as TN (Twisted Nematic) mode, VA (Vertical Alignment) mode, IPS (In Plane Switching) mode and FFS (Fringe Field Switching) mode.

The display driving circuit includes a data driving circuit 202 and a scan driving circuit 204 to write the video data voltage of the input image to the pixels. The data driving circuit 202 converts the video data RGB input from the timing controller 400 into an analog positive / negative gamma compensation voltage to generate a data voltage, and converts the data voltage into data lines D1 to Dm. Supplies). The scan driving circuit 204 sequentially supplies gate pulses (or scan pulses) synchronized with the data voltages to the gate lines G1 to Gn to select pixel lines of the display panel DIS to which the data voltages are written.

The timing controller 400 receives timing signals such as a vertical synchronization signal Vsync, a horizontal synchronization signal Hsync, a data enable signal Data Enable, DE, and a main clock MCLK input from an external host system. Display timing control signals for controlling the operation timing of the data driver circuit 202 and the scan driver circuit 204 are generated.

The scan timing control signal is inputted to a gate start pulse (GSP) and a shift register in the scan driving circuit 204 to indicate a start horizontal line at which a scan starts in one vertical period in which one screen is displayed. A gate shift clock signal (GSC) for sequentially shifting (GSP), a gate output enable signal (GOE) for controlling the output of the scan driving circuit 204, and the like.

The data timing control signal is based on a source start pulse (SSP), rising or falling edge indicating the start point of data in one horizontal period in which one horizontal line of data is displayed. A source sampling clock (SSC) for controlling the latch operation, a source output enable signal SOE for controlling the output of the data driving circuit 202, and data to be supplied to the liquid crystal cells of the display panel DIS. And a polarity control signal POL for controlling the polarity of the voltage.

The timing controller 400 aligns the video data RGB input from the host system to the display panel DIS to supply the data data to the data driving circuit 202.

The specific pattern detection circuit 402 prestores at least one or more worsted patterns causing common voltage noise, and compares the input video data RGB with the worsted patterns to determine whether the input video data RGB corresponds to the worsted pattern. Detect. The specific pattern detection circuit 402 generates the pattern detection signal WP in different logic according to whether or not the worst pattern is input. The specific pattern detection circuit 402 generates the pattern detection signal WP in the first logic when the input video data RGB corresponds to the worst pattern, and generates a second pattern when the input video data RGB corresponds to the worst pattern. The pattern detection signal WP can be generated by logic. The specific pattern detection circuit 402 may be built in the timing controller 400.

The touch screen TSP may be bonded to the upper polarizing plate POL1 of the display panel DIS as shown in FIG. 8, or may be formed between the upper polarizing plate POL1 and the upper substrate GLS1 as shown in FIG. 9. In addition, the touch screen TSP may be formed on the lower substrate in an in-cell type together with the pixel array in the display panel DIS as shown in FIG. 10. 8 to 10, "PIX" means a pixel electrode of a liquid crystal cell, "GLS2" means a lower substrate, and "POL2" means a lower polarizing plate, respectively.

The touch screen TSP includes Tx electrode lines T1 to Tj and j is a positive integer smaller than n, and Rx electrode lines R1 to Ri and i intersect the Tx electrode lines T1 to Tj. A small positive integer), and a plurality of touch sensors formed at intersections of the Tx electrode lines T1 to Tj and the Rx electrode lines R1 to Ri. The touch sensor is implemented with a mutual capacitor (Cm) formed at each intersection of the Tx electrode line and the Rx electrode line.

The touch screen driving circuit includes a Tx driving circuit 302 and an Rx driving circuit 304. The touch screen driving circuit supplies touch driving pulses to the Tx electrode lines T1 to Tj, and converts the voltage of the touch sensors into digital data through the Rx electrode lines R1 to Ri. The Tx driving circuit 302 and the Rx driving circuit 304 can be integrated in one ROIC (Read-out IC).

The Tx driving circuit 302 sets a Tx channel for outputting a touch driving pulse under the control of the touch controller 306. The Tx driving circuit 302 generates a touch driving pulse according to the driving timing control signal CONT input from the touch controller 306 and supplies the touch driving pulses to the Tx electrode lines T1 to Tj connected to the Tx channel. do. The Tx driving circuit 302 may repeatedly supply a touch driving pulse to each of the Tx electrode lines T1 to Tj in order to secure a sufficient sensing time.

The Rx driving circuit 304 receives the voltages of the touch sensors through the Rx channels connected to the Rx electrode lines R1 to Ri, and samples the sensing voltage according to the sensing enable signal input from the touch controller 306. . The Rx driving circuit 304 may repeatedly sample the output of each of the touch sensors in one touch frame in response to the touch driving pulse supplied repeatedly. The Rx driving circuit 304 converts the sampling voltage into touch raw data through analog-to-digital conversion and transmits it to the touch controller 306.

The touch controller 306 is connected to the Tx driving circuit 302 and the Rx driving circuit 304 through an interface such as an I2C bus, a SPI (serial peripheral interface), and a system bus. The touch controller 306 supplies a setup signal to the Tx driver circuit 302 to set the Tx channel to which the touch driving pulse is output. The touch controller 306 generates a sensing enable signal based on the display timing of the video data RGB, and supplies the sensing enable signal to the Rx driving circuit 304 to control the sampling timing of the voltages of the touch sensors. do.

The touch controller 306 receives the pattern detection signal WP from the specific pattern detection circuit 402 and generates a driving timing control signal CONT based on the pattern detection signal WP to generate the touch driving pulses. Control differently. When the pattern detection signal WP is input to the first logic in response to the worst pattern, the touch controller 306 controls the operation of the Tx driving circuit 302 so that the timing of generation of the touch driving pulse is determined from immediately after the default time. Delay as much as possible. When the pattern detection signal WP is input to the second logic in response to a data pattern other than the worst pattern, the touch controller 306 controls the operation of the Tx driving circuit 302 to set the timing of generation of the touch driving pulse as a default time. Keep immediately.

The touch controller 306 analyzes touch data input from the Rx driver circuit 304 by using a preset touch recognition algorithm to calculate touch coordinate values. The touch coordinate data output from the touch controller 306 may be transmitted to an external host system in a human interface device (HID) format. The host system executes an application indicated by the touch coordinate value.

FIG. 11 shows the configuration of the specific pattern detection circuit 402 shown in FIG.

Referring to FIG. 11, the specific pattern detection circuit 402 may include a memory 402A, a data operation unit 402B, and a pattern recognition unit 402C.

The memory 402A stores at least one worst pattern that causes common voltage noise. The worst pattern stored in the memory 402A may include a 1 dot vertical line pattern as shown in FIG. 2, a 1 dot check pattern as shown in FIG. 3, and a modified 2 dot check pattern as shown in FIG. 4.

The data operation unit 402B compares the input video data for one frame with the worst pattern stored in the memory 402A in a predetermined unit and outputs a comparison value COMP. For example, the data calculator 402B may subtract the input video data for one frame and the worst pattern for one frame and output the result as a comparison value COMP.

The pattern recognition unit 402C recognizes the input video data as a worst pattern only when the comparison value COMP input from the data operation unit 402B is smaller than the preset threshold value TH, and the pattern detection signal WP is recognized as a first pattern. The logic outputs the signal, and otherwise, the pattern detection signal WP is output to the second logic.

12 illustrates an example in which the touch driving timing is changed in response to the input of the worst pattern. FIG. 13 shows an experimental result in which touch performance is increased by changing the touch driving timing.

Referring to FIG. 12, as described in detail in the background art, when the worst pattern is displayed on the display panel, the common voltage Vcom does not maintain the original optimal DC level and includes large ripple components. The common voltage noise due to the worst pattern is very large.

The present invention changes the touch driving timing from the original default value to another value when the worst pattern is input in order to avoid the common voltage noise so that sensing can be performed. According to the present invention, the touch sensors are driven after a predetermined period Td has elapsed from immediately after the predetermined default time T1 when the worst pattern is input. The predetermined period Td may be selected as a time required to stabilize the common voltage Vcom to its original optimal DC level. The predetermined period Td is preferably set on the basis of the worst pattern which generates the greatest common voltage noise among the predetermined worst patterns. The default time T1 may be determined based on a specific falling edge of a specific timing control signal (eg, horizontal sync signal Hsync) for defining one horizontal period 1H.

As shown in the experimental results of FIG. 13, it can be seen that when the touch driving timing is changed as shown in FIG. 12 in response to the worst pattern input, the touch performance is remarkably improved.

Meanwhile, the present invention maintains the touch driving timing at the original default value when the input video data does not correspond to the worst pattern. That is, when the input video data does not correspond to the worst pattern, the present invention drives the touch sensors immediately after the default time T1 to secure a sufficient sensing period. When the input video data does not correspond to the worst pattern, since the common voltage noise is not greatly induced, even if the touch sensors are driven immediately after the default time T1, the sensing value distortion is small.

14 illustrates a method of improving touch performance of a display device having a touch sensor according to an embodiment of the present invention.

As illustrated in FIG. 14, in the touch performance improving method according to the present invention, when video data is input, the input video data is compared with a predetermined specific data pattern. (S10, S20) The specific data pattern causes common voltage noise. At least one Worst pattern is selected.

The touch performance improving method according to the present invention determines whether the input video data and the specific data pattern are the same (S30).

In the method of improving touch performance according to the present invention, when the input video data and the specific data pattern are the same as the determination result of S30, the touch driving timing is changed from the original default value to another value. It is driven after further elapse of a predetermined period from immediately after a predetermined default time.

In the method of improving touch performance according to the present invention, if the input video data and the specific data pattern are not the same as the result of the determination of S30, the touch driving timing is maintained at the original default value. It runs immediately after time.

As described above, the present invention changes touch driving timing at the time of inputting specific data patterns causing common voltage noise and avoids the noise, so that touch performance is generated regardless of generation of common voltage noise by specific data patterns. And touch reliability can be greatly increased.

It will be apparent to those skilled in the art that various modifications and variations can be made in the present invention without departing from the spirit or scope of the invention. Therefore, the technical scope of the present invention should not be limited to the contents described in the detailed description of the specification, but should be defined by the claims.

DIS: display panel 202: data driving circuit
204: scan driving circuit 302: Tx driving circuit
304: Rx driving circuit 306: Touch controller
400: timing controller 402: specific pattern detection circuit
WP: Pattern Detection Signal CONT: Driving Timing Control Signal
402A: Memory 402B: Data Computing Unit
402C: Pattern Recognition Unit TSP: Touch Screen

Claims (12)

A display panel having a touch screen on which touch sensors are formed;
A Tx driving circuit supplying a touch driving pulse to the Tx lines of the touch screen;
An Rx driving circuit for sampling the sensing voltages of the touch sensors received through the Rx lines of the touch screen by supplying the touch driving pulses;
A specific pattern detection circuit configured to detect whether the video data is the same as the specific data pattern by comparing the video data to be input to the display panel with a predetermined specific data pattern; And
A touch controller configured to control the timing of generation of the touch driving pulses differently according to the detection result;
And the particular data pattern is selected as at least one worst pattern that causes common voltage noise to be mixed with the sensing voltage. The method of claim 1,
The touch controller,
And changing the generation timing of the touch driving pulse from a set default value to another value when the video data is the same as the specific data pattern. 3. The method of claim 2,
The touch controller,
And delaying the generation timing of the touch driving pulse for a predetermined period from immediately after a predetermined default time when the video data is the same as the specific data pattern. The method of claim 3, wherein
And wherein the predetermined period of time is selected as a time required for the common voltage noise to be canceled and the common voltage to be applied to the display panel to be stabilized at a DC level. The method of claim 3, wherein
The predetermined period of time is a display device having a touch sensor, characterized in that set based on the worst pattern that generates the most common voltage noise among the predetermined worst pattern. The method of claim 1,
The touch controller,
And when the video data is not the same as the specific data pattern, maintaining the generation timing of the touch driving pulse immediately after a predetermined default time. A display panel having a touch screen on which touch sensors are formed, a Tx driving circuit supplying a touch driving pulse to the Tx lines of the touch screen, and the touch received through the Rx lines of the touch screen by supplying the touch driving pulse. A method of improving touch performance of a display device having an Rx driving circuit for sampling sensing voltages of sensors,
Comparing the video data to be input to the display panel with a predetermined specific data pattern to detect whether the video data is the same as the specific data pattern; And
Controlling the timing of generation of the touch driving pulse according to the detection result;
And the specific data pattern is selected as at least one worst pattern that causes common voltage noise to be mixed with the sensing voltage. The method of claim 7, wherein
Controlling the generation timing of the touch driving pulse,
And changing the generation timing of the touch driving pulse from a set default value to another value when the video data is the same as the specific data pattern. The method of claim 8,
Controlling the generation timing of the touch driving pulse,
And if the video data is the same as the specific data pattern, delaying the generation timing of the touch driving pulse for a predetermined period from immediately after a predetermined default time. The method of claim 9,
And the predetermined period is selected as a time required for the common voltage noise to be canceled and the common voltage to be applied to the display panel to be stabilized at a DC level. The method of claim 9,
The predetermined period of time, the touch performance improvement method of the display device having a touch sensor, characterized in that is set based on the worst pattern that generates the most common voltage noise among the predetermined worst pattern. The method of claim 7, wherein
Controlling the generation timing of the touch driving pulse,
And if the video data is not the same as the specific data pattern, maintaining the timing of generating the touch driving pulse immediately after a predetermined default time.

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