KR20110042585A - Touch controller increasing sensitivity, display driving circuit and display device and system having the same - Google Patents

Abstract

PURPOSE: A display device, a system thereof, a display driving circuit including a touch controller and touch controller are provided to reduce all kinds of noise. CONSTITUTION: A panel unit includes a sensing unit. A display driving circuit unit(120) generates a video data. The display driving circuit part receives one or more first timing information from an external host. A touch controller(110) senses capacitance variation of the sensing unit. The touch controller generates touch data.

Description

Touch controller increasing sensitivity, display driving circuit and display device and system having the same}

The present invention relates to a touch controller, and more particularly, to a touch controller having improved sensing sensitivity, a display driving circuit including a touch controller, a display device, and a system.

As lightweight and thin display devices are required, cathode ray tubes (CRTs) are being replaced by flat panel display devices. As such a flat panel display device, a liquid crystal display device (LCD), a field emission display (FED), an organic light emitting display (OLED), a plasma display panel (plasma display panel, PDP).

In general, such a flat panel display device includes a plurality of pixels arranged in a matrix to display an image. As an example of a flat panel display apparatus, a plurality of scan lines that transmit a gate selection signal and a plurality of data lines that transmit grayscale data are arranged to cross each other, and a plurality of pixels are arranged in the scan lines and data. Lines are formed at the intersections.

Meanwhile, a touch screen panel (eg, a capacitive touch screen panel) includes a plurality of sensing units, and the capacitance value of the sensing unit is variable when a finger or a touch pen is touched on the screen. to be. The touch screen panel is generally attached to the top of the flat panel display device, and a capacitance value corresponding thereto when the finger or the touch pen is in proximity to or in contact with the sensing unit is provided to the touch screen processor. The touch screen processor senses the capacitance of the sensing unit through a sensing line to determine whether a finger or a touch pen and the like are touched on the touch screen panel. Sensing units may be provided inside the display panel in order to reduce problems such as reduced yield, lowered brightness, and increased product thickness by attaching the touch screen panel to the display panel.

1 illustrates a general touch screen panel and a signal processor for processing a touch signal. As shown in FIG. 1, the touch screen system 10 of FIG. 1 senses a capacitance change of a touch screen panel 11 including a plurality of sensing units and a sensing unit of the touch screen panel 11, and processes the touch data. It includes a signal processor 12 for generating a.

The touch screen panel 11 includes a plurality of sensing units arranged in a row direction and a plurality of sensing units arranged in a column direction. As shown, the touch screen panel 11 includes a plurality of rows in which a sensing unit is disposed, and a plurality of sensing units are disposed in each row. The sensing units arranged in each row are electrically connected to each other. In addition, the touch screen panel 11 includes a plurality of columns in which a sensing unit is disposed, and a plurality of sensing units are disposed in each column. The sensing units arranged in each column are electrically connected to each other.

The signal processor 12 generates touch data by sensing a change in capacitance of the sensing unit of the touch screen panel 11. For example, by sensing capacitance changes from a plurality of rows and a plurality of columns, the touch screen panel 11 determines whether a finger or a touch pen is in contact with the touch screen panel 11.

However, parasitic capacitance components exist in the sensing units provided in the touch screen panel 11. As the parasitic capacitance components, a horizontal capacitance component generated between the sensing units and a vertical capacitance generated between the sensing unit and the display panel are provided. There is an ingredient. In the case where the total parasitic capacitance has a large value, the amount of change in capacitance caused by the touch of a finger or a touch pen or the like has a relatively small value compared to the parasitic capacitance. For example, as the finger or the touch pen approaches the sensing unit, the capacitance value of the corresponding sensing unit increases. However, when the sensing unit has a high parasitic capacitance value, the sensing sensitivity decreases. In addition, a change in the electrode voltage VCOM provided to the upper panel of the display panel causes a problem of sensing noise of the touch operation through vertical parasitic capacitance.

In addition to the parasitic capacitance components as described above, as a factor that may affect the touch screen operation, there are various noises present in an ideal environment. For example, electromagnetic noise acts as noise in the air, and noise from the skin is generated in skin accumulated noise and the touch screen system itself. These noises have a problem that may lower the sensing sensitivity of the touch screen device.

An object of the present invention is to provide a display controller, a display device and a system including a touch controller and a touch controller that can reduce the influence of parasitic capacitance components and noise of the sensing unit. It is done.

In order to achieve the above object, the display device according to an embodiment of the present invention, the panel unit including the sensing unit for performing a touch screen operation, and receives at least one first timing information from an external host And a display driving circuit unit generating image data to display an image in the panel unit and connected to the sensing unit to sense a change in capacitance of the sensing unit, and to detect the first timing information from the outside and the display driving circuit unit from the outside. And a touch controller configured to generate touch data in synchronization with at least one of the timing information generated.

Meanwhile, a touch controller connected to a sensing unit through a plurality of sensing lines according to an embodiment of the present invention is connected to the sensing unit, and has a first capacitance corresponding to a parasitic capacitance of the sensing unit and a change amount of capacitance due to a touch operation. A voltage readout circuit for generating a first voltage signal having a voltage level, an input signal having the first voltage signal and a predetermined frequency, and excluding a component of the first voltage level due to the parasitic capacitance; A first amplifier circuit for performing an amplification operation on two voltage levels and generating a second voltage signal according to the amplification operation; An analog-to-digital converter that receives the output of the integrating circuit and converts it into a digital signal to generate touch data; It is characterized by.

On the other hand, the display system connected to the sensing unit through a plurality of sensing lines according to an embodiment of the present invention, a panel unit including a host controller, the sensing unit for performing a touch screen operation, and at least from the host controller Receives a first timing information, and is connected to the display driving circuit unit for generating image data in order to implement an image to the panel unit and the sensing unit to sense a change in capacitance of the sensing unit, the first timing information and And a touch controller configured to generate touch data based on at least one of timing information generated from the display driver circuit.

According to the touch controller of the present invention as described above, a display driving circuit including the touch controller, a display device, and a system, the sensing sensitivity of the touch screen operation is improved by reducing the influence of parasitic capacitance components and various noises included in the sensing unit. It can be effected.

DETAILED DESCRIPTION In order to fully understand the present invention, the operational advantages of the present invention, and the objects achieved by the practice of the present invention, reference should be made to the accompanying drawings that illustrate preferred embodiments of the present invention.

Hereinafter, exemplary embodiments of the present invention will be described in detail with reference to the accompanying drawings. Like reference numerals in the drawings denote like elements.

FIG. 2A is a block diagram illustrating a parasitic capacitance component generated in sensing units of a touch screen panel according to the present invention, and FIG. 2B is a graph illustrating a change in capacitance of the sensing unit according to a touch operation. 2C is a graph showing a change in capacitance when noise is present.

As shown in FIG. 2A, the touch screen panel 21 includes a plurality of sensing units SU, which are disposed adjacent to or attached to the display panel 22 for displaying an image. Can be. As an example, the display panel 22 shown in FIG. 2A represents a top plate of the display panel provided with a predetermined electrode voltage VCOM. For example, the top plate of the panel may be provided with a VCOM voltage as a common electrode voltage as the top plate of the liquid crystal display panel, and a cathode voltage having a DC voltage in the organic light emitting display panel.

The touch screen panel 21 includes sensing units SU connected to a plurality of sensing lines arranged in a row direction (x direction) and sensing units connected to a plurality of sensing lines arranged in a column direction (y direction). Field SU is provided. Each sensing unit has a variable capacitance value when a finger, a touch pen, or the like is in close proximity or touch. By sensing the capacitance change of the sensing unit through a plurality of sensing lines to generate a sensing signal, and processing the sensing signal, whether or not the touch on the touch screen panel 21 can be determined.

The sensing units SU have parasitic capacitance components in their arrangement. As an example, the parasitic capacitance component may include a horizontal parasitic capacitance component Ch generated between adjacent sensing units, and a vertical parasitic capacitance component Cv generated between the sensing unit and the display panel 22. When the parasitic capacitance value is larger than the capacitance component caused by the proximity or contact of the finger or the touch pen with the sensing unit, even if the capacitance value of the sensing unit is changed by the touch operation, the sensitivity for sensing the sensing unit is lowered. .

As shown in FIG. 2B, each sensing unit SU has a basic capacitance component Cb including a parasitic capacitance component and changes its capacitance value due to proximity or contact of an object such as a finger or a touch pen. do. As an example, when a conductive material approaches or contacts the sensing unit, the capacitance value of the sensing unit is increased. A section A of FIG. 2B is a state in which the conductive material is not in contact, and the capacitance value of the sensing unit may have a Cb value. Section B of FIG. 2B illustrates a case in which the conductive material contacts the sensing unit, and section C represents a case in which the conductive material approaches the sensing unit. As illustrated, when the conductive material contacts the sensing unit, an increase amount Csig of the capacitance value increases, and when the conductive material approaches the sensing unit, the increase amount Csig ′ of the capacitance value decreases.

On the other hand, when there is a variety of noise as shown in Figure 2c the noise component can have a large influence on the capacitance value, so that the processor or controller (not shown) only touch the touch object with the increased or decreased capacitance value Whether the touch position and the touch position cannot be accurately determined, and as a result, the sensing sensitivity of the touch screen device may be extremely degraded.

3 is a block diagram illustrating a touch controller according to an embodiment of the present invention. In order to show the operation of the touch controller 110, a display driving circuit 120 for driving an image on a display panel and a host controller 130 for controlling the overall operation of the touch controller 110 are shown. .

As illustrated, the touch controller 110 may include a signal processor 111 and a touch data generator 112. In addition, the display driving circuit 120 may include a timing controller 121, a gate driver 122, and a source driver 123 for implementing an image on the display panel.

The signal processor 111 performs an overall control operation of a circuit inside the touch controller 110 in relation to the touch screen operation. In addition, the touch data generator 112 is electrically connected to the plurality of sensing units SU through a sensing line, and generates a sensing signal by sensing a change in capacitance of the sensing units SU by a touch operation. In addition, the touch data is generated and output by processing the generated sensing signal. The illustrated signal processor 111 or the host controller 130 performs a logical operation based on the touch data to determine whether the touch operation is performed on the touch screen and the position at which the touch operation is performed. Determine.

The touch controller 110 may receive at least one timing information used to drive a display panel (not shown), and use the touch controller 110 in an operation for generating touch data. The timing information may be generated from the timing controller 121 in the display driving circuit 120, and the timing information may be generated directly from the host controller 130. 3 illustrates an example in which the timing information is generated by the timing controller 121 and the touch controller 110 receives the timing information from the timing controller 121. The signal processor 111 receives at least one timing information and provides a control signal ctrl based thereon to the touch data generator 112.

The control signal ctrl is generated based on the waveform of the timing information. The control signal ctrl may be directly generated by the timing controller 121 and provided to the signal processor 111, or the signal processor 111 may use timing information provided by the timing controller 121. Can be generated. In addition, as described above, the host controller 130 may directly generate timing information. Similarly, the control signal ctrl is also generated directly from the host controller 130 and provided to the touch controller 110. May be When the host controller 130 generates the control signal ctrl, the control signal ctrl may be provided to the signal processor 111 or may be directly provided to the touch data generator 112. In the following description, it is assumed that the signal processor 111 generates the control signal ctrl as shown in FIG. 3.

The timing controller 121 generates at least one signal for adjusting the timing of the display operation. For example, the timing controller 121 outputs a vertical sync signal Vsync and a horizontal sync signal Hsync from an external host controller 130. May be directly input or may generate the vertical sync signal Vsync and the horizontal sync signal Hsync based on a data enable signal (not shown) provided from an external host controller 130. In addition, at least one timing signal may be generated to control generation of a common electrode voltage (eg, a VCOM voltage) and a gate line signal.

The signal processor 111 generates a control signal ctrl based on at least one timing information Timing info from the timing controller 121 and provides the touch data generator 112 with the control signal ctrl. To control the generation timing of the touch data. That is, when the voltage provided on the display panel (for example, the common electrode voltage provided to the upper panel) is changed, noise may be generated in the sensing signal, and thus the timing of generation of the touch data is provided on the display panel. The voltage is controlled to be performed in a stable section.

Meanwhile, the touch controller 110 for the touch screen operation as described above and the display driving circuit 120 for driving the image on the display panel may be implemented with the same chip. That is, in one embodiment of the present invention, since the touch controller 110 receives at least one timing information from the display driving circuit 120 and performs a synchronous operation thereto, the timing information is transmitted through wirings provided in the same chip. It is desirable to receive.

4A and 4B are block diagrams illustrating various examples of generating touch data of FIG. 3. 4A illustrates an example in which the touch controller 110 receives information (control / timing) related to timing directly from the host controller 130. In this case, the timing controller 121 may generate an operation of generating the timing information based on information from the host controller 130 and providing the timing information to the touch controller 110. . The signal processor 111 receives information related to timing (control / timing) from the host controller 130, generates a control signal ctrl based on the information, and provides the control signal ctrl to the touch data generator 112.

4B illustrates an example of multiplexing information generated from the timing controller 121 and information generated from the host controller 130 and providing the information to the touch controller 110 as timing information. To this end, a selector 130 for selectively outputting a signal may be disposed between the touch controller 110 and the display driving circuit 120 illustrated in FIG. 4B. For example, the selector 130 may be implemented as a multiplexer (MUX). The selector 130 may be disposed between the touch controller 110 and the display driving circuit 120, or may be disposed in front of the signal processor 111 in the touch controller 110. The selector 130 selectively outputs information generated from the timing controller 121 or information generated from the host controller 130 in response to a predetermined control signal (not shown). In this case, if the display driving circuit 120 operates in the normal mode, information generated from the timing controller 121 may be provided to the touch controller 110. On the contrary, when the display driving circuit 120 is in a power down mode (eg, a sleep mode), information generated from the host controller 130 may be provided to the touch controller 110.

5A and 5B are waveform diagrams illustrating an example of generating the control signal ctrl of FIG. 3. First, as shown in FIG. 5A, the horizontal synchronization signal Hsync is sequentially activated after a predetermined period of the vertical synchronization signal Vsync. In addition, the level of the common electrode voltage (eg, the VCOM voltage) is shifted in synchronization with the activation of the horizontal synchronization signal Hsync. The control signal ctrl may be generated using one or more of timing information (eg, vertical or horizontal synchronization signal, timing information for generating a common electrode voltage, DotCLK information) for driving the display panel as described above. have. Since the timing of generation of the touch data is controlled in synchronization with the timing of activation of the control signal ctrl, the generation of noise of the touch data due to the change of the voltage provided to the display panel is reduced.

5B is a waveform diagram illustrating another example of timing of generation of a control signal. As shown, there is a porch section in which the horizontal sync signal is not activated before and after the vertical sync signal Vsync, so that the voltage of the common electrode provided to the display panel does not change during the porch section. In this case, when the activation timing of the control signal ctrl is included in the porch section of the vertical synchronization signal Vsync, noise generated by a change in the voltage provided to the display panel may be reduced.

FIG. 6A is a block diagram illustrating an example embodiment of the touch data generator 112 of FIG. 3. First, as illustrated in FIG. 6A, the touch data generator 112 includes a voltage reading circuit 112_1, an amplifying circuit 112_2, an integrating citcuit 112_3, and And analog-digital converting circuit 112_4.

The voltage reading circuit 112_1 may read a voltage Vread output from each of the plurality of sensing units connected to the plurality of sensing lines included in the touch screen panel. In addition, the amplifying circuit 112_2 may amplify and output the voltage Vread read by the voltage reading circuit 20. The amplifying circuit 112_2 may sense a change in capacitance of the sensing unit by amplifying the voltage Vread output from the voltage reading circuit 112_1, and the amplified voltage Vout is an integral block, which is the next block. May be sent to circuit 112_3. In addition, the amplifying circuit 112_2 may include at least one amplifier for performing an amplifying operation, and the amplifier may include a plurality of amplifiers connected to each of the plurality of sensing lines. Alternatively, the amplification circuit 112_2 according to the embodiment of the present invention may be configured such that the amplifier is switchably connected to the plurality of sensing lines so that one amplifier is shared by the plurality of sensing lines.

The integrating circuit 112_3 may integrate the voltage Vout output from the amplifying circuit 112_2. As described above, the voltage Vout output from the amplifying circuit 112_2 may include a plurality of noise components, and noise components may be effectively removed by integrating the voltage Vout in the integrating circuit 112_3. Can be. The integrating circuit 112_3 according to an embodiment of the present invention may include any circuits capable of receiving an input signal and integrating and outputting the received input signal. Any of a variety of integrators may be used, including switched capacitor integrators or Gm-C integrators.

The analog-to-digital conversion circuit 112_4 may convert the analog voltage VADC_IN output from the integration circuit 112_3 into touch data, which is a digital signal. The touch data may be provided to a signal processor provided in the touch controller, or may be provided to a host controller external to the touch controller. By a calculation process of the touch data, whether a touch operation and a touch position on the touch screen panel may be determined.

6B is a circuit diagram illustrating an implementation example of the touch data generator of FIG. 6A. In FIG. 6B, an embodiment using a switched capacitor integrating circuit as the integrating circuit 112_3 is illustrated. As described above, the integrating circuit 112_3 Gm-C integrating circuit may be used.

The voltage reading circuit 112_1 may include a plurality of switches SW1 to SWn for controlling a connection with each of the plurality of sensing units in order to sense voltage changes from the plurality of sensing units. have. Also, the plurality of sensing units may share one driving circuit 112_11 as shown in FIG. 6B, or according to an embodiment, the voltage reading circuit 112_1 is connected to each of the plurality of sensing units. It may also include a number of driving circuits. The illustrated capacitor component Csig represents the amount of capacitance change of the sensing unit, and the illustrated capacitor component Cb represents the total capacitance component including the parasitic capacitance component.

In an embodiment in which one driving circuit 112_11 is shared as illustrated in FIG. 6B, the voltage Vread output from each sensing unit may be sequentially read. For example, when the voltage output from the first sensing unit is read by the switching operation of the first switch SW1, the remaining sensing units are configured by the switching operation of the second switch SW2 to the n-th switch SWn. It may be connected to the driving circuit 112_11 and driven. Similarly, after that, only the voltage output from the second sensing unit may be read out, and the remaining sensing units may be driven by the driving circuit.

In addition, the driving circuit 112_11 may drive each sensing unit using an input signal Vin having a predetermined frequency, and the input signal Vin may have a square wave or a sinusoidal wave having a predetermined period. It may be a sinusoidal wave, and the level or frequency of the input signal Vin may be appropriately adjusted according to the embodiment. In addition, since the driving circuit 112_11 must be able to drive a plurality of sensing units at the same time, it is preferable to include an operational amplifier capable of driving a large load.

FIG. 6C is a diagram illustrating turn-on timing of the input signal Vin and the switches SW1 to SWn of FIG. 6B. 6B and 6C, the input signal Vin may be a square wave or a sinusoidal file, and FIG. 6C illustrates a square wave as the input signal Vin. In addition, as illustrated in FIG. 6C, the input signal Vin may have a predetermined rising time and a predetermined falling time. In addition, the plurality of switches SW1 to SWn may be switched to sequentially read voltages output from the plurality of sensing units. Therefore, as shown in FIG. 6C, the plurality of switches SW1 to SWn may be sequentially turned on without overlapping each other. In addition, the time that each of the plurality of switches SW1 to SWn maintains a turn-on state may be greater than or equal to a period of the input signal Vin.

 As illustrated in FIG. 6B, the amplifier circuit 112_2 may include an amplifier 112_21 for performing an amplification operation, and the amplifier 112_21 may include at least one operational amplifier AMP1. have. A first input terminal (eg, a negative input terminal) of the operational amplifier AMP1 may be connected to a sensing unit through a sensing line to sense a change in capacitance of the sensing unit. As described above, the capacitance value of the sensing unit may include a capacitance component Cb of the touch screen panel itself and a capacitance component Csig by a touch operation. In addition, an input signal Vin having a predetermined frequency may be provided to a second input terminal (eg, a positive input terminal) of the operational amplifier AMP1. As described above, the input signal Vin may be a square wave or a sinusoidal file having a constant period, and the level or frequency of the input signal Vin may be appropriately adjusted according to an embodiment. For example, the frequency of the input signal Vin may have a frequency value within a pass band of the operational amplifier AMP1 that exhibits high-pass filtering characteristics.

In addition, a capacitor Cf may be connected between a first input terminal (eg, a negative input terminal) and an output terminal of the operational amplifier AMP1, and a predetermined resistor Rf may be further connected in parallel with the capacitor Cf. have. Due to the configuration of the circuit illustrated in FIG. 6B, the amplifier 112_21 may operate as a high pass filter having a predetermined voltage gain.

In addition, the amplification circuit 112_2 according to the embodiment of the present invention may further include a capacitor Cq for canceling the capacitance component Cb of the touch screen panel. The first input terminal (eg, negative input terminal) of the amplifier AMP1 may be connected in parallel.

By reversing the polarity of the capacitance component Cb of the touch screen panel and the polarity of the capacitor Cq, it is possible to cancel the effect of the capacitance component Cb of the touch screen panel, and thus in the embodiment of the present invention. The sensing sensitivity of the touch screen device can be improved.

In this case, the amplifying circuit 112_2 according to the embodiment of the present invention may further include a voltage adjusting circuit 111_22 for adjusting the voltage of one electrode of the capacitor Cq, and the voltage adjusting circuit 111_22 The input signal Vin, the common voltage Vcm, the resistors Rq1 and Rq2 and the amplifier AMP2 may be implemented, and a predetermined voltage Vq may be output. Accordingly, the amplifying circuit 112_2 may output an output signal Vout having a different voltage level in response to a change in capacitance of the sensing unit. The output signal Vout can be obtained by the following equation.

의 관계가 성립하는 경우에는 상기 센싱 신호(Vout)과 입력 신호(Vin)와의 관계는 다음과 같이 정리된다.If, in the above equation, the capacitance component (Cb) is completely canceled, that is,

When the relationship is established, the relationship between the sensing signal Vout and the input signal Vin is summarized as follows.

In addition, when the touch object is touched by the touch screen panel, the capacitance component Csig between the touch screen panel and the touch object has a predetermined size, and thus the voltage level of the corresponding sensing signal Vout may change. have. The operational amplifier AMP1 may analogly output the sensing signal Vout corresponding to the capacitance value of the sensing unit, and sense the voltage change of the sensing signal Vout according to the touch operation to thereby touch the touch screen panel. Presence and touch location may be determined.

On the other hand, noise may occur in the sensing signal Vout output by the amplifying circuit 112_2, and the integrating circuit 112_3 provided in the touch controller according to an embodiment of the present invention effectively reduces the influence of the noise. You can. In general, since the noise has a Gaussian distribution, the average of the noise component during a certain period may be zero. Therefore, the output voltage Vout including the noise component can be effectively removed by a predetermined integration circuit.

The integrated circuit 112_3 illustrated in FIG. 6B is an example of a switched capacitor integrated circuit, and an operation when the integrated circuit 112_3 is provided in the touch controller 110 is as follows.

The integration circuit 112_3 may include an operational amplifier AMP3 for performing an integration operation, and a capacitor C2 may be connected between a first input terminal (eg, a negative input terminal) and an output terminal of the operational amplifier AMP3. In some embodiments, a predetermined switch RST may be connected in parallel with the capacitor C2.

In addition, the second input terminal (eg, the positive input terminal) of the operational amplifier AMP3 may be provided with a common voltage Vcm, and the common voltage Vcm is an intermediate input level value of the analog-to-digital conversion circuit 112_4. It can correspond to.

In addition, a plurality of switches φ1 and φ2 and a capacitor C1 may be connected to a first input terminal (eg, a negative input terminal) of the operational amplifier AMP3. An integration operation may be performed based on the switching operation of the switches φ1 and φ2 and the charge operation of the capacitor C1. The output voltage Vout from the amplifying circuit 112_2 may be provided into the integrating circuit 112_3 via a predetermined buffer.

FIG. 6D is a waveform diagram illustrating characteristics of various signals provided to the touch controller 110 of FIG. 6B. The common voltage Vcm may be provided with a constant level, and the voltage signal Vq provided to the input signal Vin and the capacitor Cq may be centered on the common voltage Vcm and have a predetermined frequency. have. As an example, an example in which the input signal Vin and the voltage signal Vq are generated in synchronization with the horizontal synchronizing signal HSYNC is illustrated in FIG. 6D. The voltage signal Vq may be adjusted by the values of the resistors Rq1 and Rq2 connected to the amplifier AMP2. Preferably, the capacitance component Cb of the sensing unit is adjusted by adjusting the level of the voltage signal Vq. To reduce the effect of

6E is a timing diagram for illustrating the operation of the integrating circuit 112_3 in FIG. 6B. As shown in FIG. 6E, the two switches φ1 may be controlled identically, and the remaining switches φ2 may be controlled identically.

First, the switches φ1 are turned on at a time t1, and thus, the difference between the input signal Vin and the output voltage Vout may be charged in the capacitor C1.

In a state where a predetermined voltage is charged in the capacitor C1, the switches φ1 may be turned off at a time t2, and the remaining switches φ2 may be turned on. In this case, an integration operation of the operational amplifier AMP3 may be performed so that the voltage of the first input terminal (eg, the negative input terminal) of the operational amplifier AMP3 follows the voltage of the second input terminal (eg, the positive input terminal). Therefore, the integrated voltage VADC_IN may increase or decrease according to the relative magnitude of the output voltage Vout and the input signal Vin. Integrating the entire output voltage Vout may cause the integral value to be out of the dynamic range of the analog-to-digital conversion circuit 112_4, and thus, according to the embodiment of the present invention, as shown in FIG. The voltage corresponding to Vin) can be integrated over time. Therefore, an integrated value of (Vout-Vin) may be output up / down based on the common voltage Vcm. That is, the input signal of the analog-to-digital conversion circuit 112_4 is set up / down based on the common voltage Vcm, so that the output of the analog-to-digital conversion circuit 112_4 can be averaged. Therefore, low frequency noise can be effectively removed. FIG. 6F is a graph showing an integrated voltage VADC_IN of the integrating circuit 112_3. As shown in FIG. 6F, the integrated voltage VADC_IN may be output to have a level above and below the common voltage Vcm. Can be. For example, when the output voltage Vout is greater than the input signal Vin, the integrated voltage VADC_IN may be greater than the common voltage Vcm, and when the output voltage Vout is smaller than the input signal Vin. The integrated voltage VADC_IN may be smaller than the common voltage Vcm. In addition, as shown in FIG. 6F, the effect of noise does not appear at all on the integrated voltage VADC_IN. Therefore, the controller (not shown) sets an appropriate threshold value to easily determine whether the touch is performed on the touch screen panel. can do.

7 is a block diagram illustrating a touch controller according to another embodiment of the present invention.

As shown in FIG. 7, the touch controller 200 includes blocks that perform an operation for generating touch data. As an example, the touch controller 200 includes a voltage reading circuit 211_1, a first amplifier circuit 211_2, and a first block. An anti-aliasing filter 211_3, an integrating circuit 211_4 and an ADC 211_5 may be provided in the touch controller 200. In addition, the second amplifying circuit 211_6 having the same or similar characteristics as the first amplifying circuit 211_2 and the second AAF 211_7 having the same or similar characteristics as the first AAF 211_3 may include the touch controller ( 200 may be further provided. A main signal path is formed through the first amplifying circuit 211_2 and the first anti-aliasing filter 211_3, and a sub-signal is passed through the second amplifying circuit 211_6 and the second AAF 211_7. A path is formed.

When the capacitance of the sensing unit changes, an output voltage corresponding thereto is generated through the voltage reading circuit 211_1 and the first amplifier circuit 211_2. The output voltage generated by the first amplifier circuit 211_2 may pass through the first AAF 211_3. The touch data generated from the ADC 211_5 may pass through the digital filter 211_8 in a subsequent processing operation, and it is preferable to remove the high frequency component through the anti-aliasing filter before passing through the digital filter. To this end, a first AAF 211_3 may be disposed between the first amplifying circuit 211_2 and the integrating circuit 211_4.

Meanwhile, signals according to capacitance changes of a plurality of sensing units are sequentially provided to the voltage reading circuit 211_1. In order to detect a change in capacitance of the sensing units, a pulse signal having a specific frequency corresponding to each sensing unit may be voltage. Input to the read circuit 211_1. In addition, a second amplifying circuit 211_6 and a second AAF 211_7 are further provided in the touch controller 200 to extract only an actual signal component from the output of the first AAF 211_3. The pulse signal having the same phase as the pulse signal provided to the first amplifier circuit 211_2 is provided to the second amplifier circuit 211_6. Although not shown, a voltage from the sensing unit is provided to one input terminal of the amplifier provided in the first amplifying circuit 211_2, whereas one input terminal of the amplifier provided in the second amplifying circuit 211_6 is provided. It may have a structure connected to the output terminal. The output of the first AAF 211_3 and the output of the second AAF 211_7 are subtracted by a predetermined subtractor. Accordingly, only the component corresponding to the actual signal is provided to the integrating circuit 211_4.

Meanwhile, the frequency of pulse signals provided to various circuit blocks in the touch controller 200 of FIG. 7 may be synchronized with the line scan frequency of the display in order to minimize frequency interference during the display operation. As an example, the input signal Vin provided to the voltage reading circuit 211_1 may be provided to the first amplifying circuit 211_2, the second amplifying circuit 211_6, the integrating circuit 211_4, and the like. Alternatively, a voltage signal having the same or similar phase as that of the input signal Vin and having a different amplitude may be provided to the first amplifier circuit 211_2, the second amplifier circuit 211_6, the integrator circuit 211_4, and the like.

8A is a block diagram illustrating an integrated IC in which a touch controller and a display driving circuit are integrated in one chip according to an embodiment of the present invention. As shown in FIG. 8A, the integrated IC 300 includes a touch controller 310 operating as a touch controller and a display driver 330 operating as a display driving circuit. By integrating the touch controller 310 and the display driver 330 into one semiconductor chip, production cost can be reduced, and the sensing signal of the touch controller 310 and the signal generated by the display driver 330 By synchronous, it is possible to reduce the influence of noise in the touch screen operation.

The touch controller 310 may include various components for the touch screen operation. For example, the touch controller 310 may include a read circuit 311 for generating touch data, a compensator 312 for reducing parasitic capacitance components of the sensing unit, and an ADC for converting analog data into a digital signal. 313, the power voltage generator 314 for generating a power supply voltage, the memory unit 315, MCU 316, the oscillator 318 for generating a low power oscillation signal, the host controller 400 and the signal The interface unit 319 and the control logic 320 for transmitting and receiving may be provided. In addition, the display driver 330 may include a source driver 331 for generating grayscale data for a display operation, a grayscale voltage generator 332, a memory 333 for storing display data, a timing control logic 334, and one or more colors. A power generator 335 for generating a power voltage may be provided. In addition, the display driver 330 may include a CPU and an interface unit 336 for controlling overall operations or performing an interface with the host controller 400.

The touch controller 310 may receive at least one timing information from the display driver 330. As an example, the control logic 320 in the touch controller 310 may be configured with various timing information (for example, VSYCN, HSYCN, Dotclk, etc.) synchronized with the display output signal from the timing control logic 334 in the display driver 330. ). The control logic 320 may generate a control signal for controlling the generation time of the touch data using the received timing information.

The display driver 330 may also receive at least one piece of information from the touch controller 310. As an example, it is illustrated in FIG. 8A that the display driver 330 receives a status signal (for example, a sleep status signal Sleep Status) from the touch controller 310. The display driver 330 receives a sleep state signal from the touch controller 310 and performs an operation according thereto. If the touch controller 310 is in the sleep state, it indicates that the touch operation is not performed for a predetermined period of time. In this case, the display driver 330 provides timing information to the touch controller 310. The operation may be stopped, thereby enabling efficient use of power of a device (for example, a mobile device) to which the semiconductor chip is applied.

In addition, as shown in FIG. 8A, each of the touch controller 310 and the display driver 330 includes a circuit block for generating power, a memory for storing predetermined data, and a function for controlling a function of each block. A control unit and the like are provided. Accordingly, when the touch controller 310 and the display driver 330 are integrated into one semiconductor chip, the memory, the power generator, and the control unit may be connected to the touch controller 310 and the display driver 330. It can be implemented to be used in common.

FIG. 8B is a diagram illustrating a relationship between timing and a power supply voltage between the touch controller and the display driving circuit of FIG. 8A. As illustrated in (a) of FIG. 8B, the semiconductor chip 300 for driving the display apparatus may include a touch controller and a display driver, and the touch controller and the display driver may be provided with timing information and status information. At least one piece of information may be transmitted and received to each other. In addition, the touch controller and the display driver may provide or receive a power supply voltage to each other. For convenience of description, the touch controller and the display driver are briefly illustrated in FIG. 8B, and the analog front end (AFE) provided in the touch controller may be a block including a voltage reading circuit, an amplifier circuit, an integrating circuit, and an ADC. As a display device according to an embodiment of the present application, an example of an operation in which the touch controller unit provides sleep state information to the display driver and a power supply voltage used in the touch controller unit is provided from the display driver will be described below. same.

As shown in (b) of FIG. 8B, when the touch input also does not operate when the screen is turned off (when both the TSC and the display are Sleep), the display driver blocks supply of power voltage or timing information to the touch controller. do. In this case, the display driver can maintain the previous state only the state of the register therein. In this case, power consumption can be minimized.

On the other hand, if the touch input is blocked and only the display is activated (TSC is Sleep and Display is Normal), the display driver generates a power voltage for self-consumption, but the touch controller does not consume power, and thus touches the power voltage. It is not provided to the controller part. Also, the display driver does not provide timing information to the touch controller.

Meanwhile, when the touch input is activated and the display is deactivated (TSC is Normal and the Display is Sleep), since the touch input is activated, it is checked whether the touch operation is performed periodically. In this case, the display driver operates in a low power mode and remains inactive. However, in order to confirm the touch operation, the display driver generates timing information and a power supply voltage used in the touch controller, and provides the same to the touch controller.

Meanwhile, as a general case, when both the touch input and the display are activated (when the TSC and the display are both normal), the display driver generates timing information and power voltage and provides the generated timing information and power voltage to the touch controller. .

In all four cases, the power supply voltage generator of the display driver may generate the power supply voltage when at least one of the touch controller and the display driver is activated. In addition, the control logic of the display driver may generate timing information only when the touch controller operates and provide it to the touch controller.

9a, b, c, and d are views illustrating a PCB structure of a display device with a touch panel according to an embodiment of the present invention. 9A, B, C, and D show a display device having a structure in which the touch panel and the display panel are separated from each other.

As shown in FIG. 9A, the display apparatus 700 may include a window glass 710, a touch panel 720, and a display panel 740. In addition, a polarizer 730 may be further disposed between the touch panel 720 and the display panel 740 for optical characteristics.

Window glass 710 is generally made of a material such as acrylic or tempered glass, to protect the module from scratches caused by external impact or repeated touch. The touch panel 720 is formed by patterning an electrode on a glass substrate or a polyethylene terephthlate (PET) film using a transparent electrode such as indium tin oxide (ITO). The touch screen controller 721 may be mounted on a flexible printed circuit board (FPCB) in the form of a chip on board (COB). The touch screen controller 721 detects a change in capacitance from each electrode, extracts touch coordinates, and provides the same to a host controller. The display panel 740 is generally formed by bonding two sheets of glass consisting of an upper plate and a lower plate. In addition, a display driving circuit 741 is generally attached to a mobile display panel in the form of a chip on glass (COG).

9B shows an example of another PCB structure of the display device of the present invention. As shown in FIG. 9B, the touch controller 721 may be disposed on the main board 760, and a voltage signal from the sensing unit may be transmitted and received between the touch panel 720 and the touch controller 721 through FPCB. Can be. On the other hand, the display driving circuit 741 may be attached in the form of a chip on glass (COG) as shown in Figure 15a. The display driving circuit 741 may be connected to the main board 760 through an FPCB. That is, the touch controller 721 and the display driving circuit 741 may transmit and receive various information and signals to each other through the main board 760.

9C illustrates a structure of a display apparatus when the touch controller unit and the display driver unit are integrated in one semiconductor chip. As illustrated in FIG. 9C, the display apparatus 700 may include a window glass 710, a touch panel 720, a polarizer 730, a display panel 740, and the like. In particular, the semiconductor chip 751 may be attached to the display panel in the form of a chip on glass (COG). The touch panel 720 and the semiconductor chip 751 may be electrically connected to each other through an FPCB.

FIG. 9D is a diagram illustrating a panel structure of the display device of FIGS. 9A, 9B and 9C. 9D illustrates an OLED as a display device. As shown in FIG. 9D, the sensing unit may be formed by patterning a transparent electrode (ITO), and may be formed on separate glass substrates that are separated from the display panel. The glass substrate on which the sensing unit is formed may be distinguished from the window glass by a predetermined air gap or resin, and the upper and lower glasses constituting the display panel may be distinguished based on a predetermined polarizing plate. have.

10A, B, C, and D are diagrams illustrating a PCB structure when the touch panel and the display panel are integrated. As shown in FIG. 10A, the display apparatus 800 may include a window glass 810, a display panel 820, and a polarizer 830. In particular, in implementing the touch panel, the touch panel may not be formed on a separate glass substrate, but may be formed by patterning a transparent electrode on the upper plate of the display panel 820. FIG. 10A illustrates an example in which a plurality of sensing units SU are formed on an upper plate of the display panel 820. In addition, when the panel structure is formed as described above, one semiconductor chip 821 in which the touch controller and the display driving circuit are integrated may be preferably applied.

When the touch controller and the display driver are integrated in one semiconductor chip 821, the voltage signal T_sig from the sensing unit and the image data I_data from the external host are provided to the semiconductor chip 821. In addition, the semiconductor chip 821 processes the image data I_data to generate grayscale data for driving the actual display device and provide the grayscale data to the display panel. To this end, the semiconductor chip 821 may include a pad related to the touch data T_data and a pad related to the image data I_data and grayscale data (not shown). The semiconductor chip 821 receives the voltage signal T_sig from the sensing unit through a conductive line connected to one side of the touch panel. In arranging the pads on the semiconductor chip 821, it is preferable to dispose the pad receiving the voltage signal T_sig at a position adjacent to the conductive line for transmitting the voltage signal T_sig. Preferred at Although not shown in FIG. 10A, when the conductive line for providing grayscale data to the display panel is located opposite to the conductive line for transmitting the touch data voltage signal T_sig, the pad for providing the grayscale data may also be located. The voltage signal T_sig may be disposed to be opposite to the pad receiving the voltage signal T_sig.

10B has a structure substantially similar to that of the display device of FIG. 10A, wherein the voltage signal from the sensing unit is not directly provided to the semiconductor chip 821 through the FPCB but is directly provided to the semiconductor chip 821 through the conductive line. An example is shown. In addition, the display apparatus 800 of FIG. 10C also has a structure substantially similar to that of FIG. 10A, but the display apparatus 800 of FIG. 10C has a path different from that of FIG. 10A in which a voltage signal from the sensing unit is transferred to the semiconductor chip 821. The case is shown. In this case, among the pads disposed on the semiconductor chip 821, the pad receiving the voltage signal from the sensing unit is configured to be located relatively close to the conductive line.

FIG. 10D is a diagram illustrating a panel structure of the display device of FIGS. 10A, B, and C. FIG. In the display device according to an embodiment of the present invention, the touch panel and the display panel may be effectively integrated. 10D illustrates an OLED as a display device. Rather than forming a transparent electrode (ITO (sensor)) on a separate glass substrate or PET film, a transparent electrode (ITO (sensor)) is formed directly on the top plate of the display panel as shown in FIG. 10D. In this case, it is advantageous in terms of cost and module thickness in implementing the touch display panel, but as the distance between the transparent electrode (ITO) and the top glass becomes closer, the vertical parasitic capacitance component of the sensing unit Will increase. However, according to the embodiment of the present invention described above, since the influence of the entire parasitic capacitance component including the vertical parasitic capacitance component of the sensing unit is reduced, it is possible to effectively integrate the touch panel and the display panel as described above. .

11A and 11B illustrate a structure of an FPCB and a semiconductor chip in which a touch controller unit and a display driving circuit unit are embedded. The semiconductor chip includes pads for transmitting and receiving signals related to the touch controller unit and pads for transmitting and receiving signals related to the display driving circuit unit. The pads may be electrically connected to an external touch panel, a display panel, a host controller, etc. through the connection terminal of the FPCB. When the semiconductor chip is implemented, an area in which the touch controller is located and an area in which the display driving circuit part is located may be divided. In arranging the connection terminals in the FPCB, the connection terminals connected to the signals related to the touch controller unit and the connection terminals connected to the signals related to the display driving circuit unit may be separately arranged to correspond to the pads of the semiconductor chip.

FIG. 12 is a diagram illustrating a display device including a semiconductor chip having a touch controller and a display driving circuit according to an embodiment of the present invention. 12A illustrates an example in which a semiconductor chip is disposed in a glass on glass (COG) form of a display panel, and FIG. 12B illustrates a semiconductor chip on a film of a display panel. An example is disposed in the form of a chip on film (COF). When the touch controller and the display driving circuit are arranged in separate chips, the touch controller may be generally disposed in a COF form and the display driving circuit may be generally disposed in a COG form, but according to an embodiment of the present invention The semiconductor chip in which the controller and the display driving circuit are built in may be disposed in any one of the COG and the COF.

13A and 13B illustrate an example in which the touch controller T / C according to the present invention is applied to a general liquid crystal display device. The display apparatus 900A of FIG. 13A may include a timing controller 910A for controlling the overall timing for displaying an image, and a voltage generator 920A for generating various voltages required to drive the display apparatus. . In addition, the liquid crystal display device 900A may include one or more gate drivers 930A for driving the gate lines of the display panel 950A, and one or more source drivers 940A for driving the source lines. The touch controller T / C may be provided with timing information from the timing controller 910A. Accordingly, the touch controller T / C may be configured to include the respective gate driver 930A or the respective source driver ( 940A). 13A shows an example in which a touch controller T / C is provided in each source driver 940A. The timing information provided from the timing controller 910A to the source driver 940A may be simultaneously provided to the touch controller T / C provided in the source driver 940A. The touch controller T / C detects a capacitance value of a sensing unit of a touch screen panel (not shown) that may be attached to the display panel 950A, and uses predetermined timing information provided by the timing controller 910A. To generate touch data.

Meanwhile, the display apparatus 900B of FIG. 13B illustrates an embodiment in which the touch controller T / C is provided inside the timing controller 910B. In this case, the touch controller T / C may receive timing information directly within the timing controller 910B. In addition, although not shown, the touch controller T / C may be electrically connected to a touch screen panel that may be attached to the display panel 950B. Accordingly, the touch controller T / C detects a change in capacitance of the sensing unit and thus applies touch data. May occur.

Although the present invention has been described with reference to the embodiments shown in the drawings, this is merely exemplary, and it will be understood by those skilled in the art that various modifications and equivalent other embodiments are possible. Therefore, the true technical protection scope of the present invention will be defined by the technical spirit of the appended claims.

1 is a block diagram illustrating a general touch screen panel system.

2A is a block diagram illustrating a parasitic capacitance component generated in sensing units of a touch screen panel according to the present invention.

2B is a graph illustrating capacitance change of a sensing unit according to a touch operation.

2C is a diagram illustrating the influence of noise during touch screen operation.

3 is a block diagram illustrating a touch screen controller according to an embodiment of the present invention.

4A and 4B are block diagrams illustrating various examples of generating touch data of FIG. 3.

5A and 5B are waveform diagrams illustrating an example of generating the control signal of FIG. 3.

6A is a block diagram illustrating an exemplary embodiment of the touch data generator of FIG. 3.

6B is a circuit diagram illustrating an implementation example of the touch data generator of FIG. 6A.

FIG. 6C is a diagram illustrating turn-on timing of the input signal and the switches of FIG. 6B.

FIG. 6D is a waveform diagram illustrating characteristics of various signals provided to the touch controller of FIG. 6B.

FIG. 6E is a timing diagram for illustrating the operation of the integrating circuit of FIG. 6B.

FIG. 6F is a graph illustrating an integrated voltage VADC_IN generated in the integration circuit of FIG. 6B.

7 is a block diagram illustrating a touch controller according to another embodiment of the present invention.

8 is a block diagram illustrating an integrated IC in which a touch controller and a display driving circuit are integrated in one chip according to an embodiment of the present invention.

FIG. 8B is a diagram illustrating a relationship between timing and a power supply voltage between the touch controller and the display driving circuit of FIG. 8A.

9a, b, c, and d are views illustrating a PCB structure of a display device with a touch panel according to an embodiment of the present invention.

10A, B, C, and D are diagrams illustrating a PCB structure when the touch panel and the display panel are integrated.

11A and 11B illustrate a structure of an FPCB and a semiconductor chip in which a touch controller unit and a display driving circuit unit are embedded.

FIG. 12 is a diagram illustrating a display device including a semiconductor chip having a touch controller and a display driving circuit according to an embodiment of the present invention.

13A and 13B illustrate an example in which the touch controller T / C according to the present invention is applied to a general liquid crystal display device.

 Explanation of symbols on the main parts of the drawings

110: touch controller

111: signal processor

112: touch data generator

120: display driving circuit

121: timing controller

122: gate driver

123: source driver

130: host controller

Claims (19)

A panel unit including sensing units for performing a touch screen operation; A display driving circuit unit receiving at least one first timing information from an external host and generating image data to implement an image in the panel unit; And A touch controller unit connected to the sensing unit to sense a change in capacitance of the sensing unit and generating touch data in synchronization with at least one of first timing information from the outside and timing information generated from the display driving circuit unit; Display device, characterized in that. The method of claim 1, The display driving circuit unit receives the first timing information and uses the same to generate at least one second timing information related to the implementation of the image. And the touch controller unit generates the touch data using at least one of the first and second timing information. The method of claim 2, And a multiplexer configured to receive the first timing information and the second timing information and provide one of the first timing information and the second timing information to the touch controller in response to a control signal. Display device. The method of claim 1, wherein the touch controller unit, A touch data generator connected to the sensing unit to sense a change in capacitance of the sensing unit, and to process the sensing signal according to the sensing result to generate touch data; And And a signal processor configured to control generation timing of the touch data based on the received timing information, and determine whether a touch operation is received by receiving the touch data. The method of claim 1, wherein the touch controller unit, A voltage reading circuit connected to the sensing unit and generating a first voltage signal having a first voltage level corresponding to a parasitic capacitance of the sensing unit and a capacitance change amount due to a touch operation; Receives the first voltage signal and an input signal having a predetermined frequency, performs an amplification operation on a second voltage level excluding a component of the parasitic capacitance among the first voltage levels, and a second operation according to the amplification operation. A first amplifier circuit for generating a voltage signal; And And an integrating circuit for receiving the second voltage signal from the amplifying circuit, integrating and outputting the second voltage signal. The method of claim 5, wherein the touch controller unit, And a first anti-aliasing filter disposed between the first amplifying circuit and the integrating circuit and performing an analog filtering operation on the second voltage signal. The method of claim 6, wherein the touch controller unit, A second amplifier circuit configured to receive the input signal and perform an amplification operation to generate a third voltage signal; A second anti-aliasing filter disposed between the second amplifying circuit and the integrating circuit and configured to perform an analog filtering operation on the third voltage signal; And And a subtractor which subtracts the first antialiasing filter and the second antialiasing filter from each other and provides the subtraction result to the integrating circuit. The method of claim 7, wherein The first amplifying circuit and the second amplifying circuit have the same characteristics as that of the amplifying operation, And the first anti-aliasing filter and the second anti-aliasing filter have the same characteristics as the filtering operation. The method of claim 1, And the touch controller unit generates at least one state information according to an operation state of the touch controller unit and provides the state information to the display driving circuit unit. 10. The method of claim 9, The touch controller unit may provide the sleep state information indicating the sleep state to the display driving circuit unit when the touch screen operation is not performed for a predetermined time or more. And the display driving circuit unit blocks providing timing information to the touch controller unit in response to the sleep state information. The method of claim 1, wherein the panel unit, A display panel including a first substrate and a second substrate and implementing an image corresponding to image data from the display driving circuit unit; And And a touch panel including a third substrate and having the sensing unit formed on the third substrate. The method of claim 1, wherein the panel unit, And a display panel including an upper plate and a lower plate to implement an image corresponding to the image data from the display driving circuit unit. And the sensing unit is formed on an upper plate of the display panel. The method of claim 12, And the display driving circuit unit and the touch controller unit are integrated in the same semiconductor chip. The method of claim 13, A first signal transmission path for transferring image data between the semiconductor chip and the display panel; And A second signal transmission path connected to one side of the display panel, for connecting the semiconductor chip and the sensing unit, And a pad of the semiconductor chip for receiving a signal from the sensing unit is disposed on the same side as the second signal transmission path with respect to the center portion of the display panel. In the touch controller connected to the sensing unit through a plurality of sensing lines, A voltage reading circuit connected to the sensing unit and generating a first voltage signal having a first voltage level corresponding to a parasitic capacitance of the sensing unit and a capacitance change amount due to a touch operation; Receives the first voltage signal and an input signal having a predetermined frequency, performs an amplification operation on a second voltage level excluding a component of the parasitic capacitance among the first voltage levels, and a second operation according to the amplification operation. A first amplifier circuit for generating a voltage signal; An integrating circuit for receiving the second voltage signal from the amplifying circuit, integrating and outputting the second voltage signal; And And an analog-to-digital converter that receives the output of the integrating circuit and converts it into a digital signal to generate touch data. The method of claim 15, And a first anti-aliasing filter disposed between the first amplifying circuit and the integrating circuit and configured to perform an analog filtering operation on the second voltage signal. The method of claim 16, A second amplifier circuit configured to receive the input signal and perform an amplification operation to generate a third voltage signal; A second anti-aliasing filter disposed between the second amplifying circuit and the integrating circuit and configured to perform an analog filtering operation on the third voltage signal; And And a subtractor which subtracts the first antialiasing filter and the second antialiasing filter from each other and provides the subtraction result to the integrating circuit. Host controller; A panel unit including sensing units for performing a touch screen operation; A display driving circuit unit receiving at least one first timing information from the host controller and generating image data to implement an image in the panel unit; And And a touch controller connected to the sensing unit to sense a change in capacitance of the sensing unit and to generate touch data based on at least one of the first timing information and timing information generated from the display driving circuit unit. Display system. The method of claim 18, The display driving circuit unit receives the first timing information and generates at least one second timing information related to the implementation of the image by using the first timing information. And a multiplexer configured to receive the first timing information and the second timing information and provide one of the first timing information and the second timing information to the touch controller in response to a control signal. Display system.

Images