KR101771082B1 - Touch sensing circuit and display apparatus comprising the same - Google Patents

Abstract

The present invention relates to a touch sensing circuit and a display device including the touch sensing circuit, which can improve touch sensitivity and accuracy by originally eliminating noise. The touch sensing circuit according to the present invention includes a sensing signal supplied to an inverting terminal, A first differential amplifier for differentially amplifying a first reference signal supplied to a terminal to generate a touch sensing signal; And the sensing signal supplied through the input line connected to the sensing line of the touch screen panel to generate the first reference signal, and then the generated first reference signal is applied to the non-inverting terminal of the first differential amplifier And a signal supply unit for supplying the sensing signal to the inverting terminal of the first differential amplifier.

Description

Technical Field [0001] The present invention relates to a touch sensing circuit and a display device including the touch sensing circuit.

BACKGROUND OF THE INVENTION 1. Field of the Invention [0001] The present invention relates to a touch sensing circuit and a display device including the touch sensing circuit. More particularly, the present invention relates to a touch sensing circuit and a display device including the same, which can improve touch sensitivity and accuracy by originally removing noise.

Recently, a touch screen device is additionally applied as an input device such as various multimedia devices (e.g., a notebook computer, a mobile phone, and a smart phone) or various display devices (e.g., a monitor and a television) have.

A general touch screen device includes a touch screen panel including a plurality of sensing lines formed to correspond to an implementation method such as a resistive type or a capacitive type and a touch sensing circuit for sensing a signal of a plurality of sensing lines Respectively. Here, the resistance film type is a method of sensing a change in resistance value due to contact between two substrates when pressure is applied to the screen by a finger or a stylus pen, and the electrostatic capacitance type sensing a change in capacitance due to a user's touch Method.

A general touch sensing circuit includes a differential amplifier that differentially amplifies a reference voltage of a direct current (DC) voltage or a ground voltage and a sensing voltage supplied through a sensing line to output a touch sensing signal, and a touch sensing circuit And an analog-to-digital converter for converting the analog signal.

However, a general touch sensing circuit has a problem that the touch sensitivity is degraded and the accuracy is degraded due to a misunderstanding or a malfunction according to a change of a reference voltage due to a noise component generated from the outside, the periphery, or the self. For example, in a capacitive touch screen device, a touch sensing circuit amplifies an absolute value of a voltage level of a sensing signal corresponding to a change in capacitance to generate a touch sensing signal. Therefore, even when the user does not touch the touch screen panel However, it may be misleading or malfunctioning to recognize the user's touch. In particular, when the display generating a noise component is located near the touch sensing circuit, the sensing signal and the reference voltage are more severely changed due to the noise component. Therefore, in this case, a problem that the general touch sensing circuit causes more serious errors or malfunctions have.

SUMMARY OF THE INVENTION The present invention has been made to solve the above problems, and it is an object of the present invention to provide a touch sensing circuit and a display device including the touch sensing circuit, which can improve touch sensitivity and accuracy by originally eliminating noise.

According to an aspect of the present invention, there is provided a touch sensing circuit including: a first differential amplifier for generating a touch sensing signal by differentially amplifying a sensing signal supplied to an inverting terminal and a first reference signal supplied to a non-inverting terminal; And the sensing signal supplied through the input line connected to the sensing line of the touch screen panel to generate the first reference signal, and then the generated first reference signal is applied to the non-inverting terminal of the first differential amplifier And a signal supply unit for supplying the sensing signal to the inverting terminal of the first differential amplifier.

Wherein the signal supply unit samples the sensing signal according to a first switching signal to generate the first reference signal and then supplies the generated first reference signal to a non-inverting terminal of the first differential amplifier, And the sensing signal is supplied to an inverting terminal of the first differential amplifier in accordance with a second switching signal different from the first switching signal.

Wherein the signal supply unit includes: a first switching device that is switched according to the first switching signal and outputs the sensing signal supplied through the input line; Wherein the sampling signal supplied through the first switching element is sampled when the first switching element is turned on and the first reference signal is sampled using the sampled sampling voltage when the first switching element is off, A sampling circuit for generating and supplying to the non-inverting terminal of the first differential amplifier; A second switching element which is switched according to the second switching signal to selectively output the sensing signal supplied through the input line; And a second switching device for storing the sensing signal supplied through the second switching device when the second switching device is turned on and the stored sensing signal when the second switching device is off, And a storage capacitor for supplying the inverted voltage to the inverting terminal.

Wherein the first and second switching elements are sequentially turned on / off in a touch scan interval for detecting whether or not the touch panel is touched, and the second switching element is turned on / (On) / Off (Off) after the power is turned on / off.

And the sampling circuit includes a sampling capacitor connected between the first switching device and the non-inverting terminal of the first differential amplifier.

The sampling circuit comprising: an operational amplifier including an inverting terminal connected to the sampling capacitor and a non-inverting terminal connected to the reference power supply; And a feedback capacitor connected between the output terminal of the operational amplifier and the non-inverted terminal.

Wherein the touch sensing circuit includes: a filter unit for filtering the touch sensing signal supplied from an output terminal of the first differential amplifier to generate a second reference signal; And a second differential amplifier for amplifying the touch sensing signal supplied to the inverting terminal through the output terminal of the first differential amplifier and the second reference signal supplied to the non-inverting terminal through the filter section to generate a final touch sensing signal, And an amplifier.

The filter unit may include a high pass filter, and the second reference signal may be a signal passing through the high pass filter.

A filter capacitor connected between an output terminal of the first differential amplifier and a non-inverting terminal of the second differential amplifier; And a filter resistor connected between a non-inverting terminal of the second differential amplifier and a ground power source.

Wherein the touch sensing circuit includes a touch sensing signal supplied to the inverting terminal of the second differential amplifier and a delay for synchronizing the phase of each of the second reference signals supplied to the non-inverting terminal of the second differential amplifier through the filter unit, And a circuit is further included.

And the delay circuit is connected between the output terminal of the first differential amplifier and the inverting terminal of the second differential amplifier to delay the touch sensing signal.

The delay circuit may include an RC circuit including a resistor and a capacitor, or may include the RC circuit and an operational amplifier.

The touch sensing circuit may further include an analog-to-digital converter for converting the final touch sensing signal output from the second differential amplifier to digital touch sensing data.

The touch sensing circuit may further include an analog-to-digital converter for converting the touch sensing signal output from the first differential amplifier to digital touch sensing data.

According to an aspect of the present invention, there is provided a display device including: a display panel; A display panel driver for displaying an image on the display panel; A touch screen panel including a plurality of first and second sensing lines formed to cross each other; And a touch panel driver for driving the touch screen panel, wherein the touch panel driver includes the touch sensing circuit.

Wherein the touch panel driver includes a touch driver for supplying a touch scan signal to one of the first and second sensing lines; A touch sensing unit including the touch sensing circuit connected to the remaining sensing lines of the first and second sensing lines; And a touch control unit for driving the touch driving unit and the touch sensing unit under the control of the display panel driving unit.

Wherein the touch sensing circuit is configured to be connected to each of the remaining sensing lines of the first and second sensing lines, wherein each of the plurality of touch sensing circuits converts the touch sensing signal into digital touch sensing data, And an analog-to-digital converter for providing the analog signal to the control unit.

The touch sensing unit may further include a multiplexer connected to the remaining sensing lines of the first and second sensing lines and selectively supplying the sensing signal supplied from each sensing line to the touch sensing circuit according to a mux control signal The touch sensing circuit may further include an analog-to-digital conversion unit converting the touch sensing signal into digital touch sensing data and providing the touch sensing data to the touch sensing unit.

Wherein the touch sensing circuit is connected to each of the remaining sensing lines of the first sensing line and the second sensing line, and the touch sensing unit is connected to each of the plurality of touch sensing circuits, A multiplexer for selectively outputting the touch sensing signal; And an analog-to-digital converter converting the touch sensing signal output from the multiplexer into digital touch sensing data and providing the touch sensing data to the touch control unit.

Wherein the touch sensing circuit includes: a filter unit for filtering the touch sensing signal supplied from an output terminal of the first differential amplifier to generate a second reference signal; And a second differential amplifier for amplifying the touch sensing signal supplied to the inverting terminal through the output terminal of the first differential amplifier and the second reference signal supplied to the non-inverting terminal through the filter section to generate a final touch sensing signal, And further comprising an amplifier.

The filter unit may include a high pass filter, and the second reference signal may be a signal passing through the high pass filter.

Wherein the touch sensing circuit includes a touch sensing signal supplied to the inverting terminal of the second differential amplifier and a delay for synchronizing the phase of each of the second reference signals supplied to the non-inverting terminal of the second differential amplifier through the filter unit, And a circuit is further included.

And the delay circuit is connected between the output terminal of the first differential amplifier and the inverting terminal of the second differential amplifier to delay the touch sensing signal.

Wherein the touch sensing circuit is configured to be connected to each of the remaining sensing lines of the first and second sensing lines, wherein each of the plurality of touch sensing circuits outputs the final touch sensing signal output from the second differential amplifier in digital form And an analog-to-digital conversion unit for converting the touch-sensitive data into touch-sensitive data and providing the touch-sensitive data to the touch control unit.

The touch sensing unit may further include a multiplexer connected to the remaining sensing lines of the first and second sensing lines and selectively supplying the sensing signal supplied from each sensing line to the touch sensing circuit according to a mux control signal The touch sensing circuit may further include an analog-to-digital conversion unit converting the final touch sensing signal output from the second differential amplifier into digital touch sensing data and providing the touch sensing data to the touch control unit.

Wherein the touch sensing circuit is connected to each of the remaining sensing lines of the first and second sensing lines, and the touch sensing unit is connected to an output terminal of the second differential amplifier of each of the plurality of touch sensing circuits, A multiplexer for selectively outputting the final touch sensing signal supplied from the second differential amplifier according to a mux control signal; And an analog-to-digital converter converting the final touch sensing signal output from the multiplexer into digital touch sensing data and providing the touch sensing data to the touch control unit.

The touch screen panel is formed inside the display panel. The touch panel driving unit is included in the display panel driving unit.

As described above, the touch sensing circuit and the display device including the same according to the present invention have the following effects.

First, a part of the sensing signal is sampled during a predetermined period of the touch scan interval to generate a first reference signal of the first differential amplifier, thereby minimizing the influence of noise components, particularly low frequency noise, and improving the touch sensitivity and accuracy .

Second, the touch sensitivity and accuracy do not deteriorate even if it is located near the display generating the noise component.

Third, the second reference signal of the second differential amplifier is generated by passing only the noise component included in the touch sensing signal through the filter unit, thereby minimizing the influence of the noise component, thereby further improving the touch sensitivity and accuracy have.

Fourth, during the generation of the second reference signal in the filter unit, the touch sensing signal is delayed to synchronize the phases of the second reference signal and the touch sensing signal, thereby minimizing the influence of noise components, thereby further improving the touch sensitivity and accuracy .

FIG. 1 is a view schematically showing a touch sensing circuit according to a first embodiment of the present invention.
FIG. 2 is a waveform diagram showing a touch scan signal supplied to the first sensing line shown in FIG. 1 and first and second switching signals supplied to the sampling circuit.
Fig. 3 is a schematic diagram of the sampling circuit shown in Fig. 1. Fig.
4 is a diagram schematically showing another embodiment of the touch sensing circuit according to the first embodiment of the present invention.
FIGS. 5A and 5B are graphs comparing touch sense data output from the analog-to-digital converter of the general touch sense circuit and the touch sense circuit according to the first embodiment of the present invention.
6 is a diagram schematically showing a touch sensing circuit according to a second embodiment of the present invention.
7 is a view schematically showing another embodiment of the touch sensing circuit according to the second embodiment of the present invention.
8 is a diagram schematically showing a touch sensing circuit according to a third embodiment of the present invention.
9 is a diagram schematically showing another embodiment of the delay circuit shown in Fig.
10 is a diagram schematically showing another embodiment of the touch sensing circuit according to the third embodiment of the present invention.
11 is a view schematically showing a display device according to an embodiment of the present invention.
12 is a view schematically showing another embodiment of the touch sensing unit shown in FIG.
13 is a view schematically showing another embodiment of the touch sensing unit shown in FIG.

Hereinafter, embodiments of the present invention will be described in detail with reference to the accompanying drawings.

FIG. 1 is a view schematically showing a touch sensing circuit according to a first embodiment of the present invention.

Referring to FIG. 1, a touch sensing circuit 200 according to a first exemplary embodiment of the present invention includes an input line 210, a first differential amplifier 220, and a signal supply unit 230.

The input line 210 is connected to a sensing line Ry formed in the touch screen panel 100. The input line 210 is supplied with a sensing signal Vsen corresponding to a change in the value of the capacitance Ctc according to a user's touch on the touch screen panel 100 from the sensing line Ry.

Meanwhile, the touch screen panel 100 includes a plurality of first sensing lines Tx and a plurality of second sensing lines Ry.

Each of the plurality of first sensing lines Tx is formed at regular intervals along the first direction (e.g., the X-axis direction). For example, each of the plurality of first sensing lines Tx is sequentially supplied with a square-wave-shaped touch scan signal having a predetermined frequency from the outside.

Each of the plurality of second sensing lines Ry is formed at regular intervals along a second direction (e.g., Y-axis direction) intersecting each of the plurality of first sensing lines Tx. Each of the plurality of second sensing lines Ry is electrically connected to each of the input lines 210 of the touch sensing circuit 110. For example, each of the plurality of second sensing lines Ry may include a touch scan signal, that is, a touch signal, which changes according to a change in capacitance Ctc depending on whether a user touches the touch screen panel 100 Vsen) is induced. The sensing signal Vsen induced in the second sensing line Ry is supplied to the input line 210 according to whether the user touches the sensing line.

In the above description of the touch screen panel 100, a touch scan signal is supplied to each of the plurality of first transmission lines Tx, and each of the plurality of second sensing lines Ry is connected to the touch sensing circuit 200 The input line 210 is connected to the input terminal 210, and vice versa.

The first differential amplifier 220 may be a differential amplifier including an inverting terminal (-), a non-inverting terminal (+), and an output terminal Vo. The first differential amplifier 220 differentially amplifies the sensing signal Vsen supplied to the inverting terminal - and the first reference signal Vref1 supplied to the non-inverting terminal + . Meanwhile, a first feedback capacitor Cf1 may be connected between the output terminal Vo and the inverting terminal (-) of the first differential amplifier 220. [

The signal supplying unit 230 generates a first reference signal Vref1 by sampling the sensing signal Vsen supplied through the input line 210 connected to the sensing line Ry of the touch screen panel 100, (+) Of the differential amplifier 220 and the sensing signal Vsen to the inverting terminal (-) of the first differential amplifier 220. That is, the signal supply unit 230 samples the sensing signal Vsen according to the first switching signal SS1 to generate the first reference signal Vref1, and supplies the generated first reference signal Vref1 to the first differential amplifier (-) of the first differential amplifier 220 according to the second switching signal SS2 different from the first switching signal SS1, and supplies the sensing signal Vsen to the non-inverting terminal + . To this end, the signal supply unit 230 includes a first switching device SW1, a second switching device SW2, a storage capacitor Cs, and a sampling circuit 232.

The first switching device SW1 is connected between the input line 210 and the sampling circuit 232 and is switched according to the first switching signal SS1 to sample the sensing signal Vsen supplied through the input line 210 0.0 > 212 < / RTI > The first switching signal SS1 is applied to the first switching element SW1 in the touch scan period TSP of the touch scan signal TScan supplied to the first sensing line Tx, Off period and an off period for turning on / off the power supply. For example, the ON period of the first switching signal SS1 overlaps the first period of the touch scan period TSP, that is, a part of the first half period. The first switching element SW1 is turned on by the ON period of the first switching signal SS1 and supplies the sensing signal Vsen to the sampling circuit 232. [

The second switching device SW2 is connected between the input line 210 and the storage capacitor Cs and switches according to the second switching signal SS2 to store the sensing signal Vsen supplied through the input line 210 And supplies it to the capacitor Cs. The second switching signal SS2 is applied to the second switching element SW2 in the touch scan period TSP of the touch scan signal TScan supplied to the first sensing line Tx, Off period and an off period for turning on / off the power supply. For example, the ON period of the second switching signal SS2 is superimposed on the second period of the touch scan period TSP, that is, a part of the second half period. The second switching device SW2 is turned on by the ON period of the second switching signal SS2 after the first switching device SW1 is turned off to store the sensing signal Vsen And supplies it to the capacitor Cs.

The first and second switching elements SW and SW2 are sequentially turned on and off in a touch scan interval TSP for detecting whether the touch panel 100 is touched or not. And the second switching element SW2 is turned on / off after the first switching element SW1 is turned on / off.

The storage capacitor Cs stores the sensing signal Vsen supplied through the second switching device SW2 when the second switching device SW2 is turned on and the storage capacitor Cs is turned off when the second switching device SW2 is turned off ) To the inverting terminal (-) of the first differential amplifier (220).

The sampling circuit 232 samples the sensing signal Vsen supplied through the first switching device SW1 when the first switching device SW1 is turned on and turns off the first switching device SW1 And supplies the first reference signal Vref1 to the non-inverting terminal (+) of the first differential amplifier 220. The first reference signal Vref1 is supplied to the non-inverting terminal (+) of the first differential amplifier 220. [ To this end, the sampling circuit 232 according to one embodiment consists of a sampling capacitor (not shown) connected between the first switching device SW1 and the non-inverting terminal (+) of the first differential amplifier 220.

The sampling capacitor samples and stores the sensing signal Vsen supplied through the first switching device SW1 when the first switching device SW1 is turned on and stores the sampled signal Vsen through the first switching device SW1, And supplies a first reference signal Vref1 corresponding to the stored sampling voltage to the non-inverting terminal (+) of the first differential amplifier 220. [

The sampling circuit 232 according to another embodiment includes a sampling capacitor Cs and an operational amplifier AMP as shown in Fig.

The sampling capacitor Cs samples and stores the sensing signal Vsen supplied through the first switching device SW1 when the first switching device SW1 is turned on and the sampling capacitor Cs (-) of the operational amplifier AMP while the sampling voltage Vsam stored at the time of Off (Off) is supplied to the inverting terminal (-) of the operational amplifier AMP.

The operational amplifier AMP is connected to the inverting terminal (-) connected to the sampling capacitor Cs, the non-inverting terminal (+) connected to the ground power supply and the non-inverting terminal (+) of the first differential amplifier 220 And an output terminal. The operational amplifier AMP amplifies the first reference signal Ref1 according to the ground voltage supplied from the ground power supply to the non-inverting terminal + and the sampling voltage Vsam supplied from the sampling capacitor Cs to the inverting terminal - ) To the non-inverting terminal (+) of the first differential amplifier 220. On the other hand, a second feedback capacitor Cf2 may be connected between the output terminal and the inverting terminal (-) of the operational amplifier AMP. In this case, the operational amplifier AMP amplifies the sampling voltage Vsam by the capacitance ratio Cs / Cf2 of the sampling capacitor Cs and the second feedback capacitor Cf2 to generate the first reference signal Ref1 do.

4, the touch sensing circuit 200 according to the first embodiment of the present invention further includes an analog-to-digital converter (ADC) connected to the output terminal of the first differential amplifier 220 .

The analog-to-digital converter ADC converts the analog touch sense signal TS output from the first differential amplifier 220 into the touch sense data TD in the digital form, To the outside.

A driving method of the touch sensing circuit 200 according to the first embodiment of the present invention described above with reference to FIGS. 1 to 3 will be schematically described as follows.

First, during the first period of the touch scan interval TSP during which the touch scan signal TScan is supplied to the first sensing line Tx, the first switching device SW1 is switched according to the first switching signal SS1 The sampling circuit 232 samples the sensing signal Vsen of the second sensing line Ry to generate the first reference signal Vref1 and outputs the generated first reference signal Vref1 to the first differential amplifier 220 To the non-inverting terminal (+).

During the second period of the touch scan period TSP in which the first switching device SW1 is turned off according to the first switching signal SS1, the second switching device SW2 is turned on according to the second switching signal SS2, The storage capacitor Cs is used to store the sensing signal Vsen of the second sensing line Ry and the stored sensing signal Vsen to the inverting terminal of the first differential amplifier 220. [ Accordingly, the first differential amplifier 220 differentially amplifies the sensing signal Vsen supplied to the inverting terminal (-) and the first reference signal Vref1 supplied to the non-inverting terminal (+) and outputs the touch sensing signal TS ). The touch sensing signal TS is converted into digital touch sensing data TD by an analog-to-digital converter (ADC) and output to the outside.

The touch sensing circuit 200 according to the first exemplary embodiment of the present invention samples a part of the sensing signal Vsen during the first period of the touch scan interval TSP and outputs the sampled signal to the first differential amplifier 220, By generating a first reference signal Vref to be supplied to the non-inverting terminal (+) of the non-inverting terminal (+), the influence of the noise component, particularly the low frequency noise, is minimized and the touch sensitivity and accuracy are improved. That is, the touch sensing circuit 200 according to the first embodiment of the present invention does not supply the reference signal of the first differential amplifier 220 using a separate reference power supply, Is generated as the first reference signal Vref, even if the sensing signal Vsen changes due to the noise component, the noise component, particularly the erroneous recognition and malfunction due to the low frequency noise, is prevented or minimized. Accordingly, the touch sensing circuit 200 according to the first embodiment of the present invention does not deteriorate the touch sensitivity and accuracy even when the touch sensing circuit 200 is positioned near the display device generating the noise component.

FIGS. 5A and 5B are graphs comparing touch sense data output from the analog-to-digital converter of the general touch sense circuit and the touch sense circuit according to the first embodiment of the present invention.

As shown in FIG. 5A, the touch sensing data TD output from the analog-to-digital conversion unit of the general touch sensing circuit has a noise standard deviation of about 450. FIG. Here, the unit of the noise standard deviation may be a digital value of the touch sensing data TD having 13 bits.

5B, the touch sense data TD output from the analog-to-digital converter ADC of the touch sensing circuit 200 of the first embodiment of the present invention has a noise standard deviation of about 160 .

Therefore, the touch sensing circuit 200 according to the first embodiment of the present invention improves the noise standard deviation by about 30% compared to a general touch sensing circuit, thereby removing the influence of noise components, particularly low frequency noise, Can be improved.

6 is a diagram schematically showing a touch sensing circuit according to a second embodiment of the present invention.

6, the touch sensing circuit 300 according to the second embodiment of the present invention includes an input line 210, a first differential amplifier 220, a signal supply unit 230, a filter unit 240, And a differential amplifier 250. The input line 210, the first differential amplifier 220, and the signal supply unit 230 in the touch sensing circuit 300 according to the second embodiment of the present invention having such a configuration are the same as the above- The touch sensing circuit 200 of the first embodiment of the present invention is the same as the touch sensing circuit 200 of the first embodiment.

A noise component may be included in the sensing signal Vsen that is induced in the sensing line Rx and thus a noise component may be included in the touch sensing signal TS output from the first differential amplifier 220. [ Accordingly, the touch sensing circuit 300 according to the second embodiment of the present invention removes noise components included in the touch sensing signal TS using the filter unit 240 and the second differential amplifier 250, Thereby further improving sensitivity and accuracy. Hereinafter, the filter unit 240 and the second differential amplifier 250 will be described in detail.

The filter unit 240 is connected to the output terminal of the first differential amplifier 220 and generates a second reference signal Vref2 by filtering the touch sense signal TS output from the first differential amplifier 220, And supplies the second reference signal Vref2 to the non-inverting terminal (+) of the second differential amplifier 250. To this end, the filter unit 240 according to one embodiment may be a high-pass filter composed of a filter capacitor C _F , and a filter resistor R _F. The filter capacitor C _F is connected between the output terminal of the first differential amplifier 220 and the non-inverting terminal (+) of the second differential amplifier 250 and the filter resistor R _F is connected between the output terminal of the second differential amplifier 250 Inverting terminal (+) of the grounding terminal (not shown). The filter unit 240 passes only the noise component included in the touch sensing signal TS through the high pass filter and outputs the second reference signal Vref2 corresponding to the noise component to the second differential amplifier 250, To the non-inverting terminal (+).

Meanwhile, the filter unit 240 according to another embodiment includes a filter capacitor (not shown) connected between the output terminal of the first differential amplifier 220 and the non-inverting terminal (+) of the second differential amplifier 250, And at least one switching element (not shown) for controlling charge and discharge of the filter capacitor according to the switching control signal.

The second differential amplifier 250 includes an inverting terminal (-), a non-inverting terminal (+), and an output terminal Vo. The second differential amplifier 250 supplies the second reference signal Vref2 supplied from the filter unit 240 to the non-inverting terminal (+) and the inverting terminal (-) from the output terminal of the first differential amplifier 220 And generates a final touch sensing signal (FTS) by differentially amplifying the touch sensing signal (TS). That is, the second differential amplifier 250 amplifies the voltage difference between the reference signal Vref and the sensing signal Vsen to generate the touch sensing signal TS.

7, the touch sensing circuit 300 according to the second embodiment of the present invention includes an analog-to-digital converter (ADC) connected to the output terminal of the second differential amplifier 250, .

The analog-to-digital converter (ADC) converts the analog final touch sense signal (FTS) output from the second differential amplifier 250 into the touch sense data TD in digital form, and outputs the converted touch sense data TD ) To the outside.

Referring to FIG. 2, a method of driving the touch sensing circuit 300 according to the second embodiment of the present invention will now be described.

First, during the first period of the touch scan interval TSP during which the touch scan signal TScan is supplied to the first sensing line Tx, the first switching device SW1 is switched according to the first switching signal SS1 The sampling circuit 232 samples the sensing signal Vsen of the second sensing line Ry to generate the first reference signal Vref1 and outputs the generated first reference signal Vref1 to the first differential amplifier 220 To the non-inverting terminal (+).

During the second period of the touch scan period TSP in which the first switching device SW1 is turned off according to the first switching signal SS1, the second switching device SW2 is turned on according to the second switching signal SS2, The storage capacitor Cs is used to store the sensing signal Vsen of the second sensing line Ry and the stored sensing signal Vsen to the inverting terminal of the first differential amplifier 220. [ Accordingly, the first differential amplifier 220 differentially amplifies the sensing signal Vsen supplied to the inverting terminal (-) and the first reference signal Vref1 supplied to the non-inverting terminal (+) and outputs the touch sensing signal TS ).

The second differential amplifier 250 generates a second reference signal Vref2 by filtering the touch sense signal TS output from the first differential amplifier 220 and outputs the generated second reference signal Vref2 to the second differential amplifier 250. [ To the non-inverting terminal (+). Accordingly, the second differential amplifier 250 differentially amplifies the touch sensing signal TS supplied to the inverting terminal (-) and the second reference signal Vref2 supplied to the non-inverting terminal (+), (FTS). The final touch sensing signal FTS is converted into digital touch sensing data TD by an analog-to-digital converter ADC and output to the outside.

As described above, the touch sensing circuit 300 according to the second embodiment of the present invention not only provides the same effect as the first embodiment of the present invention described above, TS to generate the second reference signal Vref2 corresponding to the noise component and to amplify the voltage difference between the second reference signal Vref2 and the touch sensing signal TS including the noise component Thereby generating a final touch sense signal (FTS), thereby minimizing the influence of noise components, thereby further improving the touch sensitivity and accuracy.

8 is a diagram schematically showing a touch sensing circuit according to a third embodiment of the present invention.

8, the touch sensing circuit 400 according to the third exemplary embodiment of the present invention includes an input line 210, a first differential amplifier 220, a signal supply unit 230, a filter unit 240, (440), and a second differential amplifier (450). In the touch sensing circuit 400 according to the third embodiment of the present invention having such a configuration, the remaining configurations except for the delay circuit 440 and the second differential amplifier 450 are the same as those of the second embodiment The touch sensing circuit 300 is the same as the exemplary touch sensing circuit 300, and therefore, the description thereof will be replaced with the above description, and the same reference numerals will be given below.

The delay circuit 440 delays the touch sensing signal TS supplied from the first differential amplifier 220 by the filter unit 240 for a filtering time during which the second reference signal Vref2 is generated, To the inverting terminal (-) of the inverter 450. That is, the delay circuit 440 receives the touch sensing signal TS to be supplied to the inverting terminal (-) of the second differential amplifier 450 and the non-inverting terminal (+) of the differential amplifier 450 through the filter unit 240, ) Of the second reference signal (Vref2) to be supplied to the second reference signal (Vref2).

The delay circuit 440 according to the first embodiment includes a resistor (not shown) connected between the output terminal of the first differential amplifier 220 and the inverting terminal (-) of the second differential amplifier 450, And a capacitor (not shown) connected between the inverting terminal (-) of the amplifier 450 and the ground power source. The delay circuit 440 according to the first embodiment delays the touch sensing signal TS supplied from the first differential amplifier 220 for a filtering time according to the RC time constant of the resistor and the capacitor, To the inverting terminal (-) of the inverter 450.

The delay circuit 440 according to the second embodiment includes an RC circuit 442, a second resistor R2, a third resistor R3 and an operational amplifier 444 as shown in Fig. 9 .

The RC circuit 442 delays the touch sensing signal TS supplied from the first differential amplifier 220 by a predetermined time in accordance with the RC time constant of the resistor Rl and the capacitor Cd to generate the third reference signal Vref3, And supplies the generated third reference signal Vref3 to the non-inverting terminal (+) of the operational amplifier 444.

The second resistor R2 is connected between the output terminal of the first differential amplifier 220 and the inverting terminal (-) of the operational amplifier 444. The third resistor R3 is connected between the output terminal Vo and the inverting terminal (-) of the operational amplifier AMP. Here, each of the second and third resistors R2 and R3 has the same resistance value.

The operational amplifier 444 is connected to the inverting terminal (Vdd) through the second resistor R2 in accordance with the third reference signal Vref3 supplied to the non-inverting terminal (+) according to the RC time constant of the resistor R1 and the capacitor Cd -) and supplies the delayed touch sensing signal TS 'to the inverting terminal (-) of the second differential amplifier 450. The second touch sensing signal TS'

8, the second differential amplifier 450 includes an inverting terminal (-), a non-inverting terminal (+), and an output terminal Vo. The second differential amplifier 450 receives the second reference signal Vref2 supplied from the filter unit 240 to the non-inverting terminal (+) and the delayed touch sensing signal Vref2 supplied from the delay circuit 440 to the inverting terminal (TS ') to generate a final touch sensing signal (FTS). That is, the second differential amplifier 450 amplifies the voltage difference between the second reference signal Vref2 and the delayed touch sense signal TS 'to generate the final touch sense signal FTS.

10, the touch sensing circuit 400 according to the third embodiment of the present invention includes an analog-to-digital converter (ADC) connected to the output terminal of the second differential amplifier 450, .

The analog-to-digital converter (ADC) converts the analog final touch sense signal (FTS) output from the second differential amplifier 450 into the touch sense data TD in digital form and outputs the converted touch sense data TD ) To the outside.

Referring to FIG. 2, a method of driving the touch sensing circuit 400 according to the third embodiment of the present invention will now be described.

First, during the first period of the touch scan interval TSP during which the touch scan signal TScan is supplied to the first sensing line Tx, the first switching device SW1 is switched according to the first switching signal SS1 The sampling circuit 232 samples the sensing signal Vsen of the second sensing line Ry to generate the first reference signal Vref1 and outputs the generated first reference signal Vref1 to the first differential amplifier 220 To the non-inverting terminal (+).

During the second period of the touch scan period TSP in which the first switching device SW1 is turned off according to the first switching signal SS1, the second switching device SW2 is turned on according to the second switching signal SS2, The storage capacitor Cs is used to store the sensing signal Vsen of the second sensing line Ry and the stored sensing signal Vsen to the inverting terminal of the first differential amplifier 220. [ Accordingly, the first differential amplifier 220 differentially amplifies the sensing signal Vsen supplied to the inverting terminal (-) and the first reference signal Vref1 supplied to the non-inverting terminal (+) and outputs the touch sensing signal TS ).

Then, the touch sensing signal TS output from the first differential amplifier 220 is filtered to generate the second reference signal Vref2, the touch sensing signal TS is delayed, and the generated second reference signal Vref2 is generated. (+) Of the second differential amplifier 450 and supplies the delayed touch sensing signal TS 'to the inverting terminal (-) of the second differential amplifier 250. Accordingly, the second differential amplifier 450 differentially amplifies the delayed touch sensing signal TS 'supplied to the inverting terminal (-) and the second reference signal Vref2 supplied to the non-inverting terminal (+), And generates a sensing signal (FTS). The final touch sensing signal FTS is converted into digital touch sensing data TD by an analog-to-digital converter ADC and output to the outside.

Accordingly, the touch sensing circuit 400 according to the third embodiment of the present invention not only provides the same effect as the first embodiment of the present invention described above, The second reference signal Vref2 corresponding to the noise component is generated while the filter unit 240 generates the second reference signal Vref2 while the touch sensing signal TS is generated The second touch sensing signal TS 'is delayed and the voltage difference between the second reference signal Vref2 and the delayed touch sensing signal TS' is amplified to generate the final touch sensing signal FTS, thereby minimizing the influence of noise components, .

11 is a view schematically showing a display device including a touch sensing circuit according to an embodiment of the present invention.

Referring to FIG. 11, a display device according to an embodiment of the present invention includes a display panel 500, a display panel driver 600, a touch screen panel 700, and a touch panel driver 800.

First, a display device according to an embodiment of the present invention may be implemented as a flat panel display device such as a liquid crystal display device or an organic light emitting display device. Hereinafter, it is assumed that the display device is a liquid crystal display device.

The display panel 500 includes a liquid crystal layer formed between the upper substrate and the lower substrate.

The lower substrate includes a plurality of pixels formed in pixel regions defined by intersections of a plurality of data lines (DL) and a plurality of gate lines (GL). Each of the plurality of pixels includes a thin film transistor, a pixel electrode, and a storage capacitor. The thin film transistor is switched in accordance with a gate signal supplied to the gate line GL to supply a data voltage supplied to the data line DL to the pixel electrode. The pixel electrode forms an electric field in the liquid crystal layer in accordance with the data voltage supplied from the thin film transistor. The storage capacitor is connected to the pixel electrode to maintain the voltage of the pixel electrode.

The upper substrate includes a black matrix, a color filter, a common electrode, and the like. The black matrix defines an aperture region corresponding to the pixel region of the lower substrate. The color filter comprises red, green, and blue color filters formed in the aperture region. The common electrode is formed on the front surface of the upper substrate and faces the pixel electrode of each pixel. At this time, the common electrode may be formed in each pixel of the lower substrate according to the driving mode according to the driving method of the liquid crystal layer.

The liquid crystal layer controls the amount of light transmitted from the backlight unit in accordance with the electric field by the difference voltage between the data voltage supplied to the pixel electrode and the common voltage supplied to the common electrode.

The display panel 500 may further include an upper polarizer attached to the upper substrate and a lower polarizer attached to the lower substrate.

The display panel driving unit 600 may include a timing control unit 610, a gate driving circuit unit 620, and a data driving circuit unit 630.

The timing controller 610 generates alignment data R, G, and B by aligning input data RGB input from an external system body (or a graphics card) so as to be suitable for driving the display panel 500, And supplies the alignment data R, G, and B to the data driving circuit unit 620. Here, the input data (RGB) comprises touch screen data.

The timing control unit 610 may control the timing of driving the gate driving circuit unit 620 and the data driving circuit unit 630 using a timing synchronization signal TSS input from an external system body And generates a gate control signal (GCS) and a data control signal (DCS).

The timing controller 610 generates a touch control signal TCS for driving the touch panel driver 800 based on the timing synchronization signal TSS or the data control signal DCS.

The gate driving circuit unit 620 generates a gate signal according to the gate control signal GCS supplied from the timing control unit 610 and sequentially supplies the gate signal to the gate line GL. Here, the gate driving circuit portion 620 may be formed on the lower substrate at the same time as the thin film transistor is formed, and may be embedded in the lower substrate of the display panel 500.

The data driving circuit unit 630 latches the alignment data R, G, and B supplied from the timing control unit 610 in accordance with the data control signal DCS supplied from the timing control unit 610, After the polarity analog gamma voltage is used to convert the latched alignment data (R, G, B) into a plurality of positive / negative polarity analog data voltages, a polarity data voltage corresponding to the polarity control signal is selected, And supplies them to the corresponding data lines DL to be synchronized.

The display panel driver 600 may be integrated into a single chip so as to include both the timing controller 610, the gate driver circuit 620, and the data driver circuit 630, and may be mounted on the lower substrate.

The touch screen panel 700 includes a plurality of first sensing lines Tx and a plurality of second sensing lines Ry.

Each of the plurality of first sensing lines Tx is formed at regular intervals along the first direction (e.g., the longitudinal direction of the gate line).

Each of the plurality of second sensing lines Ry is formed at regular intervals along a second direction (e.g., the longitudinal direction of the data line) intersecting each of the plurality of first sensing lines Tx.

Meanwhile, the touch screen panel 700 may not be attached to the display panel 500, but may be formed inside the display panel 500 to reduce the thickness and weight of the display panel 500. In this case, in one embodiment, the plurality of first sensing lines Tx may be formed so as to be spaced apart from the gate lines GL when the gate lines GL are formed, and the plurality of second sensing lines Ry may be formed, May be formed on the data line DL with an insulating layer sandwiched therebetween. In another embodiment, the plurality of first sensing lines Tx may be formed on the lower substrate, and the plurality of second sensing lines Ry may be formed on the upper substrate. In another embodiment, a plurality of first sensing lines Tx and a plurality of second sensing lines Ry are formed on the same layer, and the intersections of the first sensing lines Tx and the second sensing lines Ry The first sensing line Tx or the second sensing line Ry corresponding to the portion may be connected by a connection pattern.

The touch panel driver 800 includes a touch driver 810, a touch sensing unit 820, and a touch controller 830.

The touch driver 810 generates a touch scan signal TScan in the form of a square wave having a predetermined frequency as shown in FIG. 2 under the control of the touch controller 830 and outputs the touch scan signal TScan to a plurality of first sensing lines Tx Sequentially.

The touch sensing unit 820 senses a touch scan signal, i.e., a sensing signal, induced in the plurality of second sensing lines Ry, according to whether the user touches the touch screen panel 700, and generates touch sensing data. That is, when the user touches the touch screen panel 700, capacitance values applied to the first and second sensing lines Tx and Ry are changed. Accordingly, the touch sensing unit 820 senses a touch scan signal, that is, a sensing signal induced in each of the plurality of second sensing lines Ry according to a change in the electrostatic capacitance value, and generates touch sensing data.

The touch sensing unit 820 may include a plurality of touches that are connected to the plurality of second sensing lines Ry to sense the sensing signals of the plurality of second sensing lines Ry to generate touch sensing data, And a sensing circuit.

Each of the plurality of touch sensing circuits is the same as the touch sensing circuit of any one of the touch sensing circuits 200, 300, and 400 of the first to third embodiments of the present invention shown in FIG. 4, FIG. 7, The description thereof will be substituted by the above description.

The touch sensing unit 820 according to another embodiment includes a multiplexer (MUX) and a touch sensing circuit 200/300/400 as shown in FIG.

The multiplexer MUX successively connects each of the plurality of second sensing lines Ry1 to Ryn to one touch sensing circuit 200/300/400 in accordance with the mux control signal MCS so that each second sensing line Ry1 To Ryn) to the touch sensing circuit 200/300/400.

One touch sensing circuit 200/300/400 senses a sensing signal Vsen supplied from a multiplexer MUX to generate touch sensed data TD and outputs the generated sensed sensed data TD to a touch controller 830). To this end, one touch sensing circuit 200/300/400 may be any of the touch sensing circuits 200, 300, 400 of the first through third embodiments of the present invention shown in FIG. 4, FIG. 7, It is constructed in the same manner as one touch sensing circuit, so that the description thereof will be replaced with the above description. 4, 7, or 10, the input line 210 of the touch sensing circuit 200/300/400 is not connected to the second sensing lines Ry1 to Ryn, but is connected to the output terminal of the multiplexer (MUX) Respectively.

13, the touch sensing unit 820 includes a plurality of touch sensing circuits 200/300/400, a multiplexer MUX, and one analog-to-digital converter (ADC) ).

Each of the plurality of touch sensing circuits 200/300/400 is connected to each of the plurality of second sensing lines Ry1 to Ryn to sense the sensing signals of the plurality of second sensing lines Ry1 to Ryn, (TS) or a final touch sense signal (FTS). The plurality of touch sensing circuits 200/300/400 may be any one of the touch sensing circuits 200, 300, and 400 of the first through third embodiments of the present invention shown in FIGS. 1, 6, The touch sensing circuit of the second embodiment is constructed in the same manner as the touch sensing circuit of FIG.

The multiplexer MUX multiplexes the touch sense signal TS or the final touch sense signal FTS supplied from each of the plurality of touch sense circuits 200/300/400 according to the mux control signal MCS into one analog- (ADC) sequentially.

One analog-to-digital converter (ADC) converts the touch sense signal TS or the final touch sense signal FTS sequentially supplied from the multiplexer MUX into the touch sense data TD in digital form, 830).

In the above description, the multiplexer (MUX) and the analog-to-digital converter (ADC) are each formed as a single unit. However, the present invention is not limited to this, and the total number of the plurality of second sensing lines Ry1 to Ryn may be divided into N groups , And one multiplexer (MUX) and one analog-to-digital converter (ADC) may be configured for each group.

In the above description of the touch panel driver 800, each of the plurality of first sensing lines Tx is connected to the touch driver 810, and each of the plurality of second sensing lines Ry is connected to the touch sensing unit 820 However, the present invention is not limited to this, and vice versa.

11, the touch control unit 830 drives the touch driving unit 810 and the touch sensing unit 820 in response to the touch control signal TCS supplied from the timing control unit 610 of the display panel driving unit 600 . 2, in response to the touch control signal TCS, the touch control unit 830 performs touch sensing within a touch scan interval TSP for sensing whether the touch screen panel 700 is touched, The first and second switching elements SW1 and SW2 of the unit 820 are sequentially turned on and off and the first switching element SW1 is turned on / And then generates first and second switching signals SS1 and SS2 for turning on / off the second switching device SW2 and supplies the first and second switching signals SS1 and SS2 to the touch sensing unit 820. [

The touch control unit 830 analyzes touch sensing data TD provided from the touch sensing unit 820 to generate touch position information TPD and outputs the generated touch position information TPD to an external system body Or a graphics card). Alternatively, the touch controller 830 supplies the touch position information TPD to the timing controller 610 of the display panel driver 600 so that the touch position information TPD is supplied to the external system body (not shown) through the timing controller 610 Or a graphics card).

The display device according to the embodiment of the present invention includes the touch sensing circuit 200/300/400 according to the first, second, or third embodiment of the present invention, It is possible to improve the touch sensitivity and accuracy of the touch panel.

Meanwhile, the touch panel driver 800 of the display device may be included in the display panel driver 600 described above. Alternatively, the touch driving unit 810 of the touch panel driving unit 800 is incorporated in the gate driving circuit unit 620 of the display panel driving unit 600, and the touch sensing unit 820 of the touch panel driving unit 800 And may be embedded in the circuit portion 630.

It will be understood by those skilled in the art that the present invention may be embodied in other specific forms without departing from the spirit or essential characteristics thereof. It is therefore to be understood that the above-described embodiments are illustrative in all aspects and not restrictive. The scope of the present invention is defined by the appended claims rather than the detailed description and all changes or modifications derived from the meaning and scope of the claims and their equivalents are to be construed as being included within the scope of the present invention do.

100, 700: touch screen panel 200, 300, 400: touch sensing circuit
210: input line 220: first differential amplifier
230: signal supply unit 232: sampling circuit
240: filter unit 250, 450: second differential amplifier
440: Delay circuit 500: Display panel
600: display panel driver 610: timing controller
620: Gate driving circuit part 630: Data driving circuit part
800: touch panel driver 810: touch driver
820: Touch sensing unit 830: Touch control unit

Claims (28)

A first differential amplifier for generating a touch sensing signal by differentially amplifying a sensing signal supplied to the inverting terminal and a first reference signal supplied to the non-inverting terminal; And
The sensing signal supplied through the input line connected to the sensing line of the touch screen panel is sampled to generate the first reference signal and then the generated first reference signal is supplied to the non-inverting terminal of the first differential amplifier And a signal supply unit for supplying the sensing signal to the inverting terminal of the first differential amplifier,
Wherein the signal supply unit comprises:
A first switching element which is switched according to a first switching signal and outputs the sensing signal supplied through the input line;
Wherein the sampling signal supplied through the first switching element is sampled when the first switching element is turned on and the first reference signal is sampled using the sampled sampling voltage when the first switching element is off, A sampling circuit for generating and supplying to the non-inverting terminal of the first differential amplifier;
A second switching element that is switched according to a second switching signal after the first switching element is turned on / off and selectively outputs the sensing signal supplied through the input line; And
The sensing signal being supplied through the second switching element when the second switching element is turned on and the sensing signal being supplied to the inverting terminal of the first differential amplifier when the second switching element is off, And a storage capacitor for supplying a voltage to the terminal. delete delete delete The method according to claim 1,
Wherein the sampling circuit comprises a sampling capacitor connected between the first switching element and the non-inverting terminal of the first differential amplifier. 6. The method of claim 5,
Wherein the sampling circuit comprises:
An operational amplifier including an inverting terminal connected to the sampling capacitor and a non-inverting terminal connected to the reference power supply; And
Further comprising a feedback capacitor connected between the output terminal of the operational amplifier and the non-inverting terminal. The method according to claim 1,
A filter unit for filtering the touch sensing signal supplied from an output terminal of the first differential amplifier to generate a second reference signal; And
A second differential amplifier for generating a final touch sensing signal by differentially amplifying the touch sensing signal supplied to the inverting terminal through the output terminal of the first differential amplifier and the second reference signal supplied to the non-inverting terminal through the filter unit, The touch sensing circuit comprising: 8. The method of claim 7,
Wherein the filter section comprises a high pass filter and the second reference signal is a signal passing through the high pass filter. 8. The method of claim 7,
The filter unit includes:
A filter capacitor connected between an output terminal of the first differential amplifier and a non-inverting terminal of the second differential amplifier; And
And a filter resistor connected between the non-inverting terminal of the second differential amplifier and a ground power source. 8. The method of claim 7,
And a delay circuit for synchronizing the phase of each of the second reference signals supplied to the non-inverting terminal of the second differential amplifier through the filter portion and the touch sensing signal supplied to the inverting terminal of the second differential amplifier , Touch sensing circuit. 11. The method of claim 10,
Wherein the delay circuit is connected between the output terminal of the first differential amplifier and the inverting terminal of the second differential amplifier to delay the touch sensing signal. 12. The method of claim 11,
Wherein the delay circuit comprises or comprises an RC circuit comprising a resistor and a capacitor, or comprises an RC circuit and an operational amplifier. 8. The method of claim 7,
Further comprising an analog-to-digital converter for converting the final touch sensing signal output from the second differential amplifier to digital touch sensing data. The method according to claim 1,
Further comprising an analog-to-digital converter for converting the touch sensing signal output from the first differential amplifier to digital touch sensing data. A display panel;
A display panel driver for displaying an image on the display panel;
A touch screen panel including a plurality of first and second sensing lines formed to cross each other; And
And a touch panel driver for driving the touch screen panel,
Wherein the touch panel driving unit includes the touch sensing circuit according to any one of claims 1, 5, and 6. 16. The method of claim 15,
Wherein the touch panel driver comprises:
A touch driver for supplying a touch scan signal to any one of the first and second sensing lines;
A touch sensing unit including the touch sensing circuit connected to the remaining sensing lines of the first and second sensing lines; And
And a touch control unit for driving the touch driving unit and the touch sensing unit under the control of the display panel driving unit. 17. The method of claim 16,
Wherein the touch sensing circuit is configured to be connected to each of the remaining sensing lines of the first sensing line and the second sensing line,
Wherein each of the plurality of touch sensing circuits further comprises an analog-to-digital conversion unit for converting the touch sensing signal into digital touch sensing data and providing the touch sensing data to the touch control unit. 17. The method of claim 16,
The touch sensing unit may further include a multiplexer connected to the remaining sensing lines of the first and second sensing lines and selectively supplying the sensing signal supplied from each sensing line to the touch sensing circuit according to a mux control signal ,
Wherein the touch sensing circuit further comprises an analog-to-digital conversion unit for converting the touch sensing signal into digital touch sensing data and providing the touch sensing data to the touch control unit. 17. The method of claim 16,
Wherein the touch sensing circuit is configured to be connected to each of the remaining sensing lines of the first sensing line and the second sensing line,
The touch-
A multiplexer connected to each of the plurality of touch sensing circuits for selectively outputting the touch sensing signal supplied from the touch sensing circuit according to a mux control signal; And
Further comprising an analog-to-digital converter for converting the touch sensing signal output from the multiplexer into touch sensing data in a digital form and providing the touch sensing data to the touch controller. 17. The method of claim 16,
The touch sensing circuit includes:
A filter unit for filtering the touch sensing signal supplied from an output terminal of the first differential amplifier to generate a second reference signal; And
A second differential amplifier for generating a final touch sensing signal by differentially amplifying the touch sensing signal supplied to the inverting terminal through the output terminal of the first differential amplifier and the second reference signal supplied to the non-inverting terminal through the filter unit, And a display device. 21. The method of claim 20,
Wherein the filter unit comprises a high pass filter and the second reference signal is a signal passing through the high pass filter. 21. The method of claim 20,
Wherein the touch sensing circuit includes a touch sensing signal supplied to the inverting terminal of the second differential amplifier and a delay for synchronizing the phase of each of the second reference signals supplied to the non-inverting terminal of the second differential amplifier through the filter unit, Further comprising a circuit. 23. The method of claim 22,
Wherein the delay circuit is connected between the output terminal of the first differential amplifier and the inverting terminal of the second differential amplifier to delay the touch sensing signal. 21. The method of claim 20,
Wherein the touch sensing circuit is configured to be connected to each of the remaining sensing lines of the first sensing line and the second sensing line,
Wherein each of the plurality of touch sensing circuits further includes an analog-to-digital converter for converting the final touch sensing signal output from the second differential amplifier into digital touch sensing data and providing the touch sensing data to the touch control unit. 21. The method of claim 20,
The touch sensing unit may further include a multiplexer connected to the remaining sensing lines of the first and second sensing lines and selectively supplying the sensing signal supplied from each sensing line to the touch sensing circuit according to a mux control signal ,
Wherein the touch sensing circuit further comprises an analog-to-digital converter converting the final touch sensing signal output from the second differential amplifier into touch sensing data in digital form and providing the touch sensing data to the touch controller. 21. The method of claim 20,
Wherein the touch sensing circuit is configured to be connected to each of the remaining sensing lines of the first sensing line and the second sensing line,
The touch-
A multiplexer connected to an output terminal of a second differential amplifier of each of the plurality of touch sensing circuits for selectively outputting the final touch sensing signal supplied from the second differential amplifier according to a mux control signal; And
Further comprising an analog-to-digital converter converting the final touch sensing signal output from the multiplexer into digital touch sensing data and providing the touch sensing data to the touch control unit. 16. The method of claim 15,
Wherein the touch screen panel is built in the display panel. 16. The method of claim 15,
Wherein the touch panel driver is built in the display panel driver.

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