KR101699268B1 - Method of controlling hybrid in-cell touch sensing display - Google Patents

Abstract

A method of controlling a hybrid in-cell touch display which includes a display substrate, an optical substrate laminated on the display substrate, a lower electrode formed on the display substrate or the optical substrate, and an upper electrode insulated from the lower electrode and formed on the optical substrate, comprises a step of measuring a noise flowing into the upper electrode with respect to a plurality of frequencies, a step of selecting a detection frequency by comparing the noise measured for each frequency, a step of supplying a driving voltage to the lower electrode or the upper electrode by using a selected sensing frequency, and a step of sensing a touch position by using a change in capacitance between the upper electrode and the lower electrode. So, an accurate touch input value can be measured without the nose.

Description

{METHOD OF CONTROLLING HYBRID IN-CELL TOUCH SENSING DISPLAY}

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a touch panel control method and, more particularly, to a hybrid in-cell touch display, in which a display including a touch panel is provided with a hybrid in- And a control method of the touch display.

As an input method for controlling an electronic product including a display, there is a method using a touch panel or a method using a button. Recently, a method using a touch panel has been widely used.

There is a smart phone as an electronic product including a touch panel. In addition, there are a tablet PC, navigation, and the like. Since the touch panel is easy to use by anyone, an electronic product including a display, Touch panels are also applied to refrigerators and microwave ovens.

FIG. 1 is a view for explaining a conventional method of driving a touch panel, and FIGS. 2 to 4 are cross-sectional views for explaining the types of displays provided with the touch panel.

Referring to Figs. 1 to 4, the touch panel shown in Fig. 2 is an on-cell type, the touch panel shown in Fig. 3 is an in-cell type, and the touch panel shown in Fig. 4 is a hybrid type. For reference, the hybrid type shown in FIG. 4 is also referred to as a hybrid in-cell type.

The display includes a TFT substrate 10, a liquid crystal layer 20, a color filter 30, and a cover glass 50, when the display including the touch panel function is a liquid crystal display.

The touch panel 40 is for sensing a touch from a user, and may be configured in various forms such as a resistive type, a capacitive type, and a self type. However, in the following, a touch panel using a capacitive method will be described as an example.

The touch panel 40 includes a transmitter or a driving electrode 41 for applying a driving voltage and a receiver or receiving electrode 42 for receiving a sensing signal generated by a driving voltage. The touch sensing unit 45 includes a driving voltage supply unit 44 for applying a driving voltage to the driving electrode 41 and a sensing signal receiving unit 43 for sensing whether or not the sensing signal is received using the sensing signal received through the receiving electrode .

As shown in FIGS. 2 to 4, the touch panel 40 may be configured in various forms in the arrangement of the panel and the position of the electrode.

2, the touch panel 40 may be disposed on the color filter 30, that is, on a so-called on-cell type. In addition, as shown in FIG. 3, The electrodes 41 and 42 of the touch panel 40 may be formed in the TFT substrate 10 for the liquid crystal display device. This is called an in-cell type.

4, one of the electrodes 41 and 42 for the touch panel 40 is formed on the TFT substrate 10 and the other is formed on the color filter 30. That is, (Hybrid type)).

A hybrid type touch panel is a combination of an on-cell and an in-cell. In some cases, a common electrode used in a liquid crystal display device is used as an electrode for touching and another electrode is formed on a color filter.

5 is a view for explaining the operation of a conventional hybrid in-cell touch display.

5, the hybrid type display includes a display region I for outputting a video image and a touch region II for sensing a touch, and a display region <I> and a touch region <II> The frame is continuously repeated at regular intervals, and the video output and the touch detection are performed in real time on one display.

In the hybrid in-cell touch display, since the electrode for touch is a common electrode or is very close to the common electrode, the image display and the touch sensing can not be simultaneously driven. For example, when the hybrid in-cell touch display is operated at 60 Hz, 60 frames are repeated per second, and the display area and the touch area are time-divided for about 16 ms corresponding to each frame to sequentially perform video output and touch detection do.

As the response speed, resolution and size of the display increase, the driving time for one channel becomes relatively shorter. In this case, the performance of the video display function and the touch sensing function may be deteriorated due to insufficient charging time.

In addition, when a conventional electronic product is connected to a charger, the touch function may be deteriorated or interrupted due to unintentional noise. This is because the electrical characteristics of each charger are different, and in the case of a low-cost charger, the electrical stability performance is very poor.

Therefore, the frequency used in the touch sensing may be influenced by the use of the charger or the surrounding environment, and there is a disadvantage that there is no way to solve the problem when the function is deteriorated when only one frequency is used.

The present invention provides a method of controlling a hybrid in-cell touch display in which a process of selecting one of a plurality of frequencies for touch sensing is performed in real time and an accurate touch input value can be measured without noise in a hybrid in-cell touch display.

The present invention provides a method of controlling a hybrid in-cell touch display in which noise is measured for a plurality of frequencies in a hybrid in-cell touch display, and the lack of time for a conventional touch sensing area can be solved.

According to an aspect of the present invention, there is provided a display device including a display substrate, an optical substrate stacked on the display substrate, a lower electrode formed on the display substrate or the optical substrate, A method of controlling a hybrid in-cell touch display including a top electrode formed on a substrate, the method comprising: measuring noise introduced into an upper electrode of a plurality of frequencies; comparing a noise measured for each frequency to select a detection frequency; Supplying a driving voltage to the lower electrode or the upper electrode at a detection frequency, and sensing a touch position using a capacitance change between the upper electrode and the lower electrode.

The hybrid in-cell touch display of the present invention performs a process of selecting one of a plurality of frequencies in real time, thereby minimizing disturbance to noise. As a result, it is possible to reduce a malfunction and accurately measure a touch input value.

The noise measurement may be performed in a display region for video output, a touch region for touch detection, or a boundary region of both regions, and may be variously changed according to time division or environmental conditions.

However, in a hybrid in-cell touch display, one frame may be divided into a display area and a touch area, and the touch area may be allocated with a relatively short time to perform both touch sensing and noise measurement.

In this regard, the hybrid in-cell touch display is a method for increasing the accuracy of touch sensing, and may measure noise on a plurality of frequencies in a display area for video output. That is, in dividing the display area and the touch area in one frame, by performing frequency search in the display area that can be assigned to the existing touch area, the touch resolution and the size Can be solved.

The touch sensing unit measures the noise introduced from the upper electrode by frequency and selects and stores the most stable frequency as the sensing frequency according to the noise according to each frequency.

Accordingly, a display including a touch function can search for a stable frequency with the least noise in real time, and can generate a driving voltage that is going forward with a stable frequency. In the conventional touch panel, the touch function is limited or hindered due to the noise generated from the charger or other environment. However, according to the control method of the present invention, the influence of the charger and the like can be reduced.

Substantially, among the plurality of predetermined frequencies, the smallest deviation of the noise can be selected as the detection frequency, and such noise measurement can be performed in the display zone or the touch zone. However, as described above, this noise measurement may be performed in a state in which the driving voltage is cut off, a display region, or an electrode is floated for video output.

Since the noise measuring unit measures noise introduced into a predetermined plurality of frequencies during the measurement of the noise, the noise measuring unit measures the noise introduced into the lower electrode while the common electrode or the driving voltage is applied. Measurement can be performed.

In this specification, the lower electrode may be a transmitter or a driving electrode, and the upper electrode may be a receiver or a receiving electrode, but conversely, the lower electrode may be a receiving electrode and the upper electrode may be a driving electrode.

In addition, the display substrate may be a TFT substrate for a liquid crystal display device, but may also be a substrate for an LED display device. The optical substrate is generally an optical film having other insulating properties in addition to a color filter, for example, a diffusion film, Other optical films, and the like.

The present invention is a kind of in-cell touch display in which a lower electrode can be formed in the display substrate and can be provided as a common electrode in the display substrate, but in some cases, it can be formed on the bottom surface of the optical substrate. Correspondingly, the upper electrode may be formed on the opposite side of the optical substrate, but may be formed on the same side or the same side as the lower electrode with respect to the optical substrate, if the insulating property is maintained.

According to an aspect of the present invention, a hybrid in-cell touch display includes a display substrate, an optical substrate stacked on the display substrate, a lower electrode formed on the display substrate or the optical substrate, An upper electrode formed on the optical substrate, a noise measurement unit for measuring noise introduced into the upper electrode with respect to a plurality of frequencies, a detection frequency storage unit for storing the selected detection frequency by comparing the noise measured for each frequency, And a touch sensing unit for supplying a driving voltage to the lower electrode or the upper electrode at a sensing frequency stored in the sensing frequency storage unit and calculating a touch position using a change in capacitance between the upper electrode and the lower electrode.

The detection frequency storage unit may store a frequency having a smallest variation of noise among a plurality of frequencies as a 'detection frequency'. In this case, the noise measuring unit can measure the noise at the same time as the video output or the touch detection, but can preferably operate in a state in which the driving voltage is cut off for the video output. Even if the touch sensing unit applies a common voltage or a driving voltage to the lower electrode, the noise measuring unit can independently measure the noise through the upper electrode.

The sensing frequency storage unit may store at least one previously selected sensing frequency, and the touch sensing unit may generate the driving voltage using the sensing frequency selected immediately before or using the sensing frequency previously selected.

According to another aspect of the present invention, there is provided a touch sensing apparatus for a hybrid in-cell touch display, including: a noise measuring unit for measuring noise introduced into an upper electrode of a plurality of frequencies; A sensing frequency storing unit for storing the selected sensing frequency by comparing the measured noise, a common voltage supply unit for supplying a common voltage to the lower electrode or the upper electrode for image output, and supplying a driving voltage to the sensing frequency stored in the sensing frequency storing unit for touch sensing A driving voltage supply unit, and a touch sensing unit for calculating a touch position using a change in capacitance between the upper electrode and the lower electrode.

The touch sensing device may be provided in the form of a chip. The touch sensing device may be mounted on a panel or the like for the hybrid in-cell touch display, and may be used as an apparatus for comparing frequencies in real time to apply an optimal sensing frequency.

According to the control method of the hybrid in-cell touch display according to the present invention, a process of selecting one of a plurality of frequencies for touch sensing can be performed in real time, and accurate touch input values can be measured without noise.

The hybrid in-cell touch display according to the present invention can search for the lowest noise and stable frequency in real time, and can generate a driving voltage which is progressed thereafter at a stable frequency. In the conventional touch panel, the touch function is limited or hindered due to the noise generated from the charger or other environment. However, according to the control method of the present invention, the influence of the charger and the like can be reduced.

In addition, when noise is measured for a plurality of frequencies, and noise is measured in a display area other than a conventional touch sensing area, it may not be necessary to allocate time in a conventional touch area. Therefore, adding such a configuration can solve the time shortage problem in the time allocation for the touch sensing area.

1 is a block diagram illustrating a conventional method of driving a touch panel.
FIGS. 2 to 4 are cross-sectional views for explaining the types of displays provided with the touch panel.
5 is a view for explaining the operation of a conventional hybrid in-cell touch display.
6 is a block diagram illustrating a hybrid in-cell touch display and a control method thereof according to an embodiment of the present invention.
7 is a view for explaining an operation mechanism of a hybrid in-cell touch display according to an embodiment of the present invention.
FIG. 8 is a view for explaining an operation mechanism of a hybrid in-cell touch display according to another embodiment of the present invention.
9 is a view for explaining an operation mechanism of a hybrid in-cell touch display according to another embodiment of the present invention.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the accompanying drawings. However, the present invention is not limited to the embodiments. For reference, the same numbers in this description refer to substantially the same elements and can be described with reference to the contents described in the other drawings under these rules, and the contents which are judged to be obvious to the person skilled in the art or repeated can be omitted.

FIG. 6 is a block diagram illustrating a hybrid in-line touch display and a control method thereof according to an embodiment of the present invention. FIG. 7 is a view for explaining an operation mechanism of a hybrid in-cell touch display according to an embodiment of the present invention. to be.

6, the hybrid in-cell touch display according to the present embodiment is based on a general liquid crystal display, and includes a liquid crystal panel 100 in which driving electrodes Tx1 to Txk and receiving electrodes Rx1 to Rxs are embedded, A gate driver 200 for applying a scan signal to the gate line of the liquid crystal panel 100, a data driver 300 for applying a data voltage to the data lines of the liquid crystal panel 100, a data driver 300, A timing controller 400 for controlling the touch panel 200, and a touch sensing unit 500 for sensing a touch position on the liquid crystal panel 100.

Physically, the touch sensing unit 500 is provided with a driving voltage supply unit 530 for applying a common voltage and a driving voltage to the driving electrodes, and further includes noise for measuring noise introduced from the receiving electrodes Rx1 to Rxs A measurement unit 510 and a detection frequency storage unit 520 for storing the selected detection frequency.

The liquid crystal panel 100 is provided in a stacked form of a display substrate and an optical substrate in which pixels (pixels) are formed at intersections of the data lines DL1 to DLm and the gate lines GL1 to GLn, May each be provided in a configuration including a TFT substrate and a color filter. The driving electrodes Tx1 to Txk are formed on the display substrate and can function as common electrodes for video output in this embodiment. Further, the receiving electrodes Rx1 to Rxs may be provided between the optical substrate and the cover glass.

Of course, the driving electrodes may be formed on the bottom surface of the optical substrate, and the receiving electrodes may be formed on the same side or the same side as the opposite side from the driving electrode on the same optical substrate, And can also be formed on a cover class.

The timing controller 400 receives a timing signal such as a data enable signal DE and a dot clock signal CLK from an external system to control the operation timings of the data driver 300 and the gate driver 200 And generates control signals (GCS, DCS). In addition, the timing controller 400 may perform the function of rearranging the input image data input from the external system and outputting the rearranged image data to the data driver 300.

The timing controller 400 controls the data driver 300 and the gate driver 200 and generates control signals for controlling the input / output operation timing of the touch sensing unit 500, 500 may be controlled.

The data driver 300 may convert the video data input from the timing controller 400 into an analog data voltage and supply a data voltage of one horizontal line to the data lines for every one horizontal period in which a scan signal is supplied to the gate line have.

The data driver 300 generates a sampling signal by shifting a source start pulse (SSP) from the timing controller 400 according to a source shift clock (SSC). The data driver 300 may latch the pixel data RGB (image data) input according to the source shift clock SSC according to the sampling signal to change the data voltage. In response to a source output enable (SOE) signal, a data voltage is supplied to the data lines in units of horizontal lines.

To this end, the data driver 300 may include a data sampling unit, a latch unit, a digital-analog converter, and an output buffer.

The gate driver 200 shifts a gate start pulse GSP transmitted from the timing controller 400 in accordance with a gate shift clock GSC and sequentially shifts the gate lines GL1 to GLn And supplies a scan signal having a gate-on voltage Von. The gate driver 200 supplies the gate-off voltage Voff to the gate lines GL1 to GLn during the remaining period when the scan signal of the gate-on voltage Von is not supplied.

The gate driver 200 may be formed to be independent from the panel and electrically connected to the panel in various ways. However, the gate driver 200 may be configured as a gate-in-panel (GIP) It is possible. In this case, the gate control signal for controlling the gate driver 200 may be a start signal VST and a gate clock GCLK.

Next, the driving voltage supplier 530 generates a common voltage to be supplied to the driving electrodes Tx1 to Txk for video output. The common voltage generated in the driving voltage supplier 530 is supplied to the driving electrode through the touch sensing unit 500. Of course, in some cases, a common voltage supply unit for generating a common voltage may be separately provided. In this embodiment, a common voltage and a driving voltage may be supplied from one driving voltage supply unit 530. [

The driving voltage supply unit 530 supplies a common voltage in the display region < I >, but the driving voltage in the touch region < II > The driving voltage supplied through the driving voltage supplier 530 is supplied to the driving electrode through the touch sensing unit 500. The size of the common voltage and the driving voltage may be different, and in particular, the driving voltage for touch detection may have a value larger than a common voltage for video output. In this case, the driving voltage may have the voltage corresponding to the common voltage as the low level voltage, and the higher voltage may have the high level voltage.

Referring to FIG. 7, in a display operating at 60 Hz, one frame is defined to have a period of about 16 ms, and each frame is divided into a display region <I> for image output and a touch region <II> for touch sensing.

First, in the display region < I >, the noise measuring unit 510 measures noise introduced through the receiving electrodes Rx1 to Rxs. Here, the noise measuring unit 510 measures noise on a plurality of, for example, five frequencies F1 to F5, and noise of different types may be generated through the noise measuring unit 510 (NMS: Noise Measurement Slot).

In this embodiment, only the case where the noise measuring unit 510 operates in the display zone < I > is described. It is not intended to limit the invention in any way as an embodiment. Specifically, there is an advantage in that when the noise measurement is performed on the display area <I> rather than the touch area <II>, the time for the touch area <II> can be maximized.

In addition, the noise measurement can be performed in the touch area as shown in FIG. 8, and the noise measurement can be arranged before and after the touch detection. Also, as shown in FIG. 9, the noise measurement may be performed on both the display area and the touch area, and noise may be measured even when the driving voltage is not supplied to the lower electrode, even in a floating state.

Referring again to FIG. 7, the noise measuring unit 510 or the touch sensing unit 500 may calculate the most stable noise by calculating a deviation of noise or the like. In this embodiment, since the frequency F4 has the most stable result, it is possible to determine the frequency F4 as the detection frequency and store it in the detection frequency storage unit 520. [

While the noise measuring unit 510 is operating, the common voltage Vcomm may be supplied to the driving electrode. However, the noise measuring unit 510 can measure the noise with respect to the predetermined frequency irrespective of the presence or absence of the common voltage while measuring the noise with respect to the predetermined frequencies F1 to F5. Therefore, the operation of the noise measuring unit 510 is possible even while the video output is being controlled.

According to another embodiment of the present invention, the timing controller 400 may control the noise measuring unit 510 and select the noise, but may be performed independently by the touch sensing unit 500 .

In the touch zone < II >, the driving voltage supplier 530 calls the stored sensing frequency from the sensing frequency storage unit 520 and applies the called sensing frequency to supply the driving voltage to the driving electrodes Tx1 to Txk . The sensing frequency to be called here may be the immediately preceding sensing frequency, but may alternatively be the previously selected sensing frequency. For this purpose, the sensing frequency storage unit 520 may store a plurality of sensing frequencies.

In response to the supplied driving voltage, a reception signal is sensed from the reception electrodes Rx1 to Rxs, and the touch sensing unit 500 can sense a contact position of a body such as a finger or a pen using the reception signal .

Since the reception signal from the reception electrodes Rx1 to Rxs is optimized by using the excluded driving voltage, it is possible to minimize the influence of the charger or the surrounding environment to detect the accurate position.

Particularly, since the noise measurement and the detection frequency determination are performed during the video output, i.e., in the display region < I >, the time of the touch zone < II > The touch zone < II > can be time-divided.

Finally, as described above, the touch sensing unit 500 performs a function of sensing a touch by a user using a reception signal received from the reception electrodes Rx1 to Rxs of the touch panel. That is, when a user touches a specific area of the liquid crystal panel with a finger or a pen while a driving voltage for touch detection is applied to the driving electrodes Tx1 to Txk of the touch panel, the driving electrodes Tx1 to Txk, The capacitance between the sensing electrodes Rx1 to Rxs is changed, and the change of the capacitance can change the voltage value applied to the touch sensing unit 500 through the receiving electrode.

The receiving electrodes Rx1 to Rxs are connected to the touch sensing unit 500. The touch sensing unit 500 determines whether the touch sensing unit 500 is touched by using the changed voltage value (reception signal).

The touch sensing unit 500 may be configured to determine whether a touch is made or a touch position. Alternatively, the sensing signal received through the touch sensing unit may be sensed by a touch position detector Or the timing controller 400 so that the touch position is detected.

Although the present invention has been described with reference to the preferred embodiments thereof, 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 and scope of the invention as defined in the following claims. It can be understood that

100: liquid crystal panel 200: gate driver
300: Data driver 400: Timing controller
500: Touch sensing unit 510: Noise measurement unit
520: detection frequency storage unit 530: driving voltage supply unit

Claims (14)

A control method of a hybrid in-cell touch display including a display substrate, an optical substrate laminated on the display substrate, a lower electrode formed on the display substrate or the optical substrate, and an upper electrode insulated from the lower electrode and formed on the optical substrate In this case,
Dividing a period of one frame for changing an image of the display substrate into a display region for image output and a touch region for touch detection;
Measuring a noise introduced into the upper electrode with respect to a plurality of frequencies for each frame;
Comparing the noise measured for each frequency to select a detection frequency;
Supplying a driving voltage to the lower electrode or the upper electrode in the touch zone following the selected sensing frequency; And
Sensing a touch position using a capacitance change between the upper electrode and the lower electrode,
Wherein a frequency having a small amount of noise among a plurality of frequencies is selected as a detection frequency for each frame, and a driving voltage is supplied in the touch zone following the real time. A control method of a hybrid in-cell touch display including a display substrate, an optical substrate laminated on the display substrate, a lower electrode formed on the display substrate or the optical substrate, and an upper electrode insulated from the lower electrode and formed on the optical substrate In this case,
Dividing a period of one frame for changing an image of the display substrate into a display region for image output and a touch region for touch detection;
Measuring noise introduced into the upper electrode of the plurality of frequencies in the display region of each frame;
Comparing the noise measured for each frequency to select a detection frequency;
Supplying a driving voltage to the lower electrode or the upper electrode in the touch zone following the selected sensing frequency; And
Sensing a touch position using a capacitance change between the upper electrode and the lower electrode,
Wherein a frequency having a small amount of noise among a plurality of frequencies is selected as a detection frequency for each frame, and a driving voltage is supplied in the touch zone following the real time. 3. The method according to claim 1 or 2,
Wherein measuring the noise introduced into the upper electrode is performed in a state where a driving voltage supplied to the lower electrode is cut off, a common voltage is applied to the lower electrode, or the lower electrode is floated. Control method of Insel touch display. 3. The method according to claim 1 or 2,
Wherein the sensing frequency is selected to have the smallest deviation of the noise among the plurality of frequencies. delete 3. The method according to claim 1 or 2,
A detection frequency storage unit for storing the detection frequency is provided,
Wherein the selected sensing frequency is stored in the sensing frequency storage unit before or before the step of supplying the driving voltage to the lower electrode or the upper electrode. In a hybrid in-cell touch display,
A display substrate;
An optical substrate laminated on the display substrate;
A lower electrode formed on the display substrate or the optical substrate;
An upper electrode insulated from the lower electrode and formed on the optical substrate;
A noise measuring unit for measuring a noise introduced into the upper electrode with respect to a plurality of frequencies;
A detection frequency storage unit for storing the selected detection frequency by comparing the noise measured for each frequency; And
A touch sensing unit for supplying a driving voltage to the lower electrode or the upper electrode at the sensing frequency stored in the sensing frequency storage unit and calculating a touch position using a change in capacitance between the upper electrode and the lower electrode; And,
Wherein the hybrid in-cell touch display time-divides a period of one frame for changing an image of the display substrate into a display area for image output and a touch area for touch detection,
Wherein the noise measuring unit measures noise introduced into the upper electrode with respect to each of the plurality of frequencies in every frame,
Wherein the detection frequency storage unit stores a frequency having a small noise among the plurality of frequencies in the display area of each frame as a detection frequency,
Wherein the touch sensing unit supplies the driving voltage in the touch zone following the real time using the sensing frequency stored in the sensing frequency storage unit. 8. The method of claim 7,
Wherein the sensing frequency storage unit stores the sensing frequency having the smallest deviation of the noise among the plurality of frequencies. 8. The method of claim 7,
Wherein the noise measuring unit measures noise introduced into the upper electrode in a state in which a driving voltage supplied to the lower electrode is cut off for outputting a video image. 10. The method of claim 9,
Wherein the noise measuring unit measures noise through the upper electrode while the touch sensing unit applies a common voltage to the lower electrode for video output. 10. The method of claim 9,
Wherein the noise measuring unit measures noise through the upper electrode while the lower electrode is floated. 8. The method of claim 7,
Wherein the sensing frequency storage unit stores at least one previously selected sensing frequency. A hybrid in-touch display including a display substrate, an optical substrate laminated on the display substrate, a lower electrode formed on the display substrate or the optical substrate, and an upper electrode insulated from the lower electrode and formed on the optical substrate A touch sensing device comprising:
A noise measuring unit for measuring a noise introduced into the upper electrode with respect to a plurality of frequencies;
A detection frequency storage unit for storing the selected detection frequency by comparing the noise measured for each frequency;
A driving voltage supplier for supplying a common voltage to the lower electrode or the upper electrode for video output and supplying a driving voltage to the sensing frequency stored in the sensing frequency storage for touch sensing; And
And a touch sensing unit for calculating a touch position using a change in capacitance between the upper electrode and the lower electrode,
Wherein the touch sensing device time-divides a period of one frame for changing an image of the display substrate into a display area for image output and a touch area for touch sensing,
Wherein the noise measuring unit measures noise introduced into the upper electrode with respect to the plurality of frequencies for each frame,
Wherein the detection frequency storage unit stores a frequency having a small noise among the plurality of frequencies in the display area of each frame as a detection frequency,
Wherein the touch sensing unit supplies a driving voltage in the touch zone following the real time using the sensing frequency stored in the sensing frequency storage unit. 14. The method of claim 13,
Wherein the noise measuring unit measures noise introduced into the upper electrode in a state in which the driving voltage supplied to the lower electrode is cut off for outputting a video image.

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