KR20100048236A - Touch controller increasing sensitivity, display driving circuit and display device having the same - Google Patents

Abstract

PURPOSE: A display driving circuit and the display device having the same are provided to improve the sensing sensitivity of a touch screen by reducing the parasitic capacitance and the interference of noise from the sensing unit. CONSTITUTION: A touch data generating unit(112) is connected to a plurality of sensing lines. The touch data generating unit senses the capacitance change of the sensing unit. The touch data generating unit process a sensing data and generates touch data. A signal processor(111) receives at least on timing information. The signal processor supplies one of timing information to the touch data generating unit in response to the timing information. The signal processor controls the generating timing of touch data.

Description

Touch controller increasing sensitivity, display driving circuit and display device 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, and a display device.

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.

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

In order to achieve the above object, the touch controller according to an embodiment of the present invention, connected to a plurality of sensing lines sense a change in capacitance of the sensing unit disposed in the sensing line, the sensing signal according to the sensing result Receives at least one timing information from a touch data generator for generating touch data and a timing controller for driving the display panel, and receives any one of the generated timing information and a signal generated in response to the timing information. And a signal processor configured to control the generation timing of the touch data by providing the touch data to the touch data generator as a control signal.

Meanwhile, the touch controller according to another embodiment of the present invention includes a sensing signal generator including at least one amplifier, and senses a capacitance change of a sensing unit disposed in a plurality of sensing lines using the at least one amplifier. And a touch data generator for generating touch data by processing a sensing signal generated based on the sensing result, and a signal processor for controlling an operation of the touch data generator, wherein each of the at least one amplifier includes: A first input terminal is connected to the sensing line and a second input terminal is connected to an input signal having a first frequency, and outputs a signal based on a gain of the amplifier as the sensing signal.

Meanwhile, the touch controller according to another embodiment of the present invention includes at least one amplifier for sensing a change in capacitance of a sensing unit disposed in a plurality of sensing lines, and a capacitor connected to the at least one amplifier, respectively. And a touch data generator configured to process sensing signals generated based on the sensing result to generate touch data, wherein each of the at least one amplifier has a first input connected to a corresponding sensing line and a second input connected to a first input. A first electrode connected to a first input terminal of the amplifier, a second electrode connected to a second input signal synchronized with the first input signal, and the first input connected to the first input terminal of the amplifier. The signal and the second input signal, characterized in that the synchronization to any one frequency of the voltages provided to the display panel All.

Meanwhile, the sensing signal generator according to an embodiment of the present invention includes at least one amplifier connected to the sensing unit through a sensing line in order to sense a change in capacitance of the sensing unit having a variable capacitance value corresponding to a touch operation. Wherein each of the at least one amplifier comprises a first input coupled to the sensing line and a second input coupled to a first input signal having a first frequency, the first input coupled between the first input and the output; An output signal including a capacitor, wherein the amplifier performs a filtering operation having a predetermined pass band, the first frequency having a frequency value within the pass band, and having a gain reflecting a change in capacitance of the sensing unit. Is generated as a sensing signal.

On the other hand, the display driving circuit according to an embodiment of the present invention, the display panel driving circuit unit including a timing controller for generating at least one timing information for driving the display panel and disposed to detect the touch operation on the touch screen panel And a touch controller configured to generate a sensing signal by sensing a capacitance change of the sensing unit provided in the touch screen panel, and to process the sensing signal, wherein the touch controller is configured to change the capacitance of the sensing unit through a sensing line. Detects the signal, generates a sensing signal, receives the timing information from the touch data generator and the timing controller, which processes the sensing signal to generate touch data, and generates the timing information in response to the received timing information and the timing information. Which of the signals And a signal processor configured to control the generation timing of the touch data by providing the control signal to the touch data generator as a control signal.

On the other hand, the display device according to an embodiment of the present invention, a display panel for implementing an image corresponding to the received image data, and a plurality of sensing units, each sensing unit has a capacitance value corresponding to the touch operation A display panel driving circuit unit including a variable touch screen panel, a timing controller connected to the display panel to drive the display panel, and generating timing information related to a display operation; and a touch screen panel connected to the touch screen panel. And a touch controller configured to detect a touch operation on the touch panel, process a signal according to a sensing result, generate touch data, and control a generation timing of the touch data in response to the timing information.

According to the touch controller, the display driving circuit and the display device of the present invention as described above, the sensitivity of the touch screen operation by reducing the influence of the noise due to the change in the parasitic capacitance component included in the sensing unit and the voltage provided to the display panel There is an effect to improve.

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.

As shown in FIG. 2, 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 and the touch position may 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 parasitic capacitance component Cback, and its capacitance value changes due to proximity or contact of an object such as a finger or a touch pen. 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 Cback value corresponding to the parasitic capacitance 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 shown in the drawing, when the conductive material contacts the sensing unit, the increase amount ΔC of the capacitance value increases, and when the conductive material approaches the sensing unit, the increase amount ΔC ′ of the capacitance value may be relatively small.

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. Also, 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 predetermined logical operation based on the touch data to determine whether the touch operation is performed on the touch screen and the location at which the touch operation is performed. do.

Preferably, the touch data generator 112 includes an amplifier (not shown) having a characteristic of reducing an influence of parasitic capacitance generated in the sensing units SU in generating a sensing signal. Preferably, the amplifier may perform a high pass filter operation having a band pass characteristic of a predetermined frequency or more, and improves a connection relationship between the voltage signal provided to the amplifier, the sensing lines and the voltage signal, and thus the parasitic capacitance of the amplifier. Can reduce the impact. Detailed operations related to this will be described later.

Also, preferably, the signal processor 111 receives at least one timing information Timing info from the timing controller 121 in the display driving circuit 120 and transmits a control signal ctrl based thereon to the touch data generator. Provided at 112. The control signal ctrl may be generated based on the waveform of the timing information. For example, the control signal ctrl may be generated directly by the timing controller 121 and provided to the signal processor 111. 111 may generate timing information provided from the timing controller 121 and provide the timing information 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.

On the other hand, 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 is preferably 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 an operation linked thereto, the timing information can be obtained through wiring provided in the same chip. It is desirable to receive.

FIG. 4A is a waveform diagram illustrating timing of generating a control signal ctrl of FIG. 3. As shown, 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 is generated using timing information for driving the display panel as described above (eg, vertical or horizontal synchronization signal, timing information for generating a common electrode voltage). Since the generation timing of the touch data is controlled by the activation timing of the control signal ctrl, the generation of noise of the touch data due to the change in the voltage provided to the display panel is reduced.

4B 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.

An additional operation of the touch controller 110 as described above will be described with reference to FIG. 3.

The touch data generator 112 is connected to the plurality of sensing units SU provided in the touch screen panel through a plurality of sensing lines, and senses a change in capacitance values of the sensing units SU, and senses the result of the sensing. Based on the generated touch data (data). For example, in response to a change in the capacitance value of the sensing units SU based on a touch operation, a sensing signal whose voltage level is changed may be generated, and reception and output operations of the sensing signal and an analog-digital conversion operation may be performed. By generating the touch data (data).

For example, in order to be generated as a sensing signal according to a change in capacitance value of a sensing unit connected through a sensing line, the touch data generator 112 may include at least one amplifier connected to a sensing unit through a sensing line. May be provided). In addition, the at least one amplifier may include a plurality of amplifiers connected to each of the plurality of sensing lines. Each amplifier generates a voltage signal having a different level as the sensing signal in response to a change in the capacitance value of the sensing unit connected to one input terminal.

The touch data generated by the touch data generator 112 may be generated using a sensing signal that is an output of the amplifier. For example, the amplifier may continuously output a sensing signal corresponding to a capacitance value of the sensing unit, periodically sample the continuously output sensing signal, and perform the touch by analog-to-digital conversion of the sampled sensing signal. It can generate data. To this end, the touch data generator 112 may include a predetermined signal output unit and an analog-to-digital converter (not shown), which will be described in detail later.

The touch screen panel on which the sensing unit is disposed may be disposed in close proximity to the display panel for displaying an image or attached to the top plate of the display panel. When variations in the various signals provided to the display panel, for example, a level variation of the common electrode voltage (for example, the VCOM voltage) provided to the display panel occur, interference caused by the level variation of the voltage occurs to the sensing signal. Noise may occur. In order to reduce the occurrence of noise, the signal processor 111 receives at least one timing information related to the display panel driving timing from the timing controller 121 and generates a control signal ctrl based thereon. The timing of generating touch data of the touch data generator 112 is controlled by the control signal ctrl, thereby reducing the possibility of error of the touch screen operation due to the noise.

A detailed configuration and operation of the touch data generator 112 shown in FIG. 3 will be described below.

5A is a circuit diagram illustrating an example of an implementation of the touch data generator of FIG. 3, and FIG. 5B is a graph illustrating frequency characteristics of the amplifier of FIG. 5A. As shown in FIG. 5A, the touch data generator 112A includes a sensing signal generator 112A_1 connected to the sensing unit to generate a sensing signal corresponding to a change in capacitance of the sensing unit. In addition, the touch data generator 112A receives and receives the sensing signal, and also outputs the received sensing signal in response to a control signal ctrl and the signal output unit (112A_2). The analog-to-digital converter 112A_3 that receives the analog signal from 112A_2 and converts it into a digital signal may further include a touch data generator 112A. Preferably, the signal output unit 112A_2 may be a sample / hold circuit for maintaining the received sensing signal and outputting the held sensing signal in response to the control signal ctrl. The touch data that may be generated as described above may be provided to the signal processor 111 in the touch controller 110 or may be provided to a host controller outside the touch screen controller 110. By a calculation process of the touch data, whether a touch operation and a touch position on the touch screen panel may be determined.

The sensing signal generator 112A_1 includes at least one amplifier AMP. The at least one amplifier AMP may include a plurality of amplifiers connected to a plurality of rows and sensing lines in a plurality of column directions provided in the touch screen panel. Alternatively, the amplifier AMP may be configured to be switchably connected to a plurality of sensing lines, such that one amplifier is shared by the plurality of sensing lines. In FIG. 5A, one amplifier is connected to one sensing line for convenience of description.

A first input terminal (eg, an inverting input terminal (−)) of the amplifier AMP is connected to the sensing unit SU through a sensing line to sense a change in capacitance of the sensing unit SU. As shown, the capacitance value of the sensing unit SU may include a parasitic capacitance component (eg, a horizontal parasitic capacitance component Ch) and a capacitance change ΔC due to a touch operation.

On the other hand, an input signal Vin having a predetermined frequency is provided to the second input terminal of the amplifier AMP. The input signal Vin may be a signal having a predetermined period (for example, square wave or sine wave), and the level and frequency of the input signal Vin may be appropriately adjusted. Preferably, the frequency of the input signal Vin has a frequency value within a pass band of the amplifier AMP that exhibits high-pass filtering characteristics. Although not shown, a DC voltage signal such as a ground voltage may be provided to the second input terminal of the amplifier connected to the remaining sensing lines other than the sensing line in which the sensing operation is performed. Accordingly, one node (the opposite node of the node connected to the sensing line) of the horizontal parasitic capacitance component Ch, which occurs between the sensing lines, is shown as having a ground voltage.

Meanwhile, a capacitor Cf may be connected between the first input terminal and the output terminal of the amplifier AMP, and a predetermined resistor Rf may be further connected in parallel with the capacitor Cf. By the circuit configuration as described above, the amplifier AMP operates as a high pass filter having a predetermined voltage gain.

보다 큰 값을 갖는 것이 바람직하다. 또한 입력신호(Vin)의 주파수가 통과 대역 내의 값을 갖는 경우, 증폭기(AMP)의 이득은

의 값을 갖는다.The amplifier AMP configured as described above generates sensing signals Vout having different voltage levels in response to the capacitance change of the sensing unit SU. 5B shows the pass band characteristics and the voltage gain of the amplifier AMP. As shown, the frequency of the input signal Vin is

It is desirable to have a larger value. Also, when the frequency of the input signal Vin has a value within the pass band, the gain of the amplifier AMP is

Has the value of.

As in the gain equation of the amplifier AMP, when a change ΔC of the capacitance value of the sensing unit SU occurs due to a touch operation, the sensing signal Vout generated by the amplifier AMP is correspondingly generated. The voltage level changes. The amplifier AMP analogously generates a sensing signal Vout corresponding to the capacitance value of the sensing unit SU. By detecting a voltage change of the sensing signal Vout according to the touch operation, whether or not the touch operation on the touch screen panel is determined is determined.

Preferably, in generating touch data using the sensing signal Vout, a control signal ctrl generated using at least one timing information is used. The signal output circuit 112A_2 receives and maintains the sensing signal Vout from the sensing signal generator 112A_1 and maintains the sensing signal Vout in response to the activation of the control signal ctrl received from the signal processor 111. Vout) to the analog-to-digital converter 112A_3. The analog-digital converter 112A_3 generates touch data by converting the received analog sensing signal into a digital signal and provides the touch data to the outside.

By the sensing operation and the touch data generation operation as described above, the presence or absence of the touch operation and the position on the touch screen can be determined, and the timing of the generation of the touch data in response to the control signal ctrl is controlled to display the display. It is possible to reduce the occurrence of noise due to the voltage level variation on the panel.

However, if the horizontal parasitic capacitance component Ch between the sensing units SU becomes large, the gain value of the amplifier AMP becomes large. In this case, in order for the output voltage of the amplifier AMP to operate in a constant region, the capacitance of the capacitor Cf connected between the first input terminal and the output terminal of the amplifier AMP should have a large value. However, when the capacitor Cf has a large value of capacitance, the change in the output voltage due to the touch operation, that is, the ΔC / Cf value becomes small, and thus the sensing sensitivity may be lowered. The sensing lines of the touch screen panel may be made of transparent conductive Indium-Tin Oxide (ITO) material. When the distance between the sensing units increases, the sensor lines are more prominent, so it is desirable to reduce the distance between the sensing units. Do. However, if the distance between the sensing units is reduced, the horizontal parasitic capacitance component Ch generated in each of the sensing units is increased, which may result in deterioration of the sensing sensitivity as described above. Hereinafter, various implementations of the touch data generator 112A capable of reducing the parasitic capacitance component to improve sensing sensitivity will be described.

6A is a circuit diagram illustrating another example of the touch data generator of FIG. 3, and is a graph illustrating filtering characteristics of the amplifier of FIG. 6A. As illustrated, the touch data generator 112B includes a sensing signal generator 112B_1 that generates a sensing signal Vout corresponding to a change in capacitance of the sensing unit SU. Also preferably, the touch data generator 112B may digitally output the analog output of the signal output unit 112B_2 and the signal output unit 112B_2 to output the received sensing signal in response to a control signal ctrl. It may further include an analog-to-digital converter 112B_3 to convert to to generate the touch data (data).

The sensing signal generator 112B_1 illustrated in FIG. 6A reduces the influence of the horizontal capacitance component (parasitic capacitance component between the sensing lines) generated in the sensing unit SU to improve sensing sensitivity. To this end, the ground voltage or the DC voltage is not provided to the amplifier AMP corresponding to the sensing line adjacent to the sensing line where the sensing operation is performed, but is input to the second input terminal (for example, the + terminal) of the adjacent amplifier. Allow signal vin to be provided.

That is, if the first electrode of the horizontal parasitic capacitor corresponds to the first sensing line to perform the sensing operation, and the second electrode of the horizontal parasitic capacitor corresponds to the second sensing line adjacent to the first sensing line, The first sensing line and the second sensing line are provided with the same voltage, thereby removing the horizontal parasitic capacitance component Ch from the gain equation of the amplifier AMP.

In FIG. 6A, although the second electrode of the horizontal parasitic capacitor is directly connected to the second input terminal of the corresponding amplifier AMP, the present invention is not limited thereto. Unlike the operation of FIG. 5A, the input signal vin is commonly transmitted to the second input terminal (+ input terminal) of the plurality of amplifiers in the embodiment of FIG. 6A. When the input signal vin is provided to the second input terminal (+ input terminal) of the amplifier AMP, the first input terminal (− input terminal) of the amplifier AMP also follows the voltage of the second input terminal (+ input terminal). That is, since the input signal vin is also provided to the second input terminal of the amplifier connected to the adjacent sensing line, the voltage of the adjacent sensing line also follows the input signal vin. Accordingly, the voltages of the first sensing line to which the sensing operation is performed and the second sensing line adjacent thereto are equal to each other so that the gain of the amplifier AMP has a value independent of the horizontal parasitic capacitance component Ch. .

값보다 더 큰 주파수를 갖도록 하는 것이 바람직하다. 또한 도 6a의 증폭기(AMP)의 이득은

의 값을 갖는다. 즉, 증폭기(AMP)의 이득은 해당 센싱 라인에 연결되는 수평 기생 커패시턴스 성분(Ch) 값과는 무관하게 된다.FIG. 6B is a graph illustrating the frequency characteristics of the amplifier AMP of FIG. 6A. As described above, the frequency of the input signal vin has a frequency value within the pass band of the amplifier AMP. That is, the input signal vin is shown in Fig. 6b.

It is desirable to have a frequency greater than the value. In addition, the gain of the amplifier AMP of FIG.

Has the value of. That is, the gain of the amplifier AMP is independent of the horizontal parasitic capacitance component Ch connected to the corresponding sensing line.

Accordingly, even if the horizontal parasitic capacitance component Ch of the sensing line of the touch screen panel increases, the gain of the amplifier AMP does not change. Accordingly, it is not necessary to increase the capacitance value of the capacitor Cf in order to make the gain of the amplifier AMP within a predetermined range. Therefore, since the value of ΔC / Cf representing the sensing sensitivity can be appropriately increased, the sensing sensitivity of the capacitance change ΔC due to the touch operation can be improved.

7A and 7B are detailed circuit diagrams illustrating the touch data generator of FIG. 6A. For convenience of description, the signal output circuit and the analog-digital converter of FIGS. 7A and 7B are not shown. Preferably, a predetermined signal circuit controlled by the control signal ctrl may be further provided in the touch data generator of 7a and b.

As mentioned above, the touch data generator 112B of FIG. 6A has a voltage applied to the adjacent sensing lines in order to reduce the influence of the horizontal parasitic capacitance Ch generated between the adjacent sensing lines. To be the same. 7A and 7B illustrate an implementation of a sensing signal generator that provides the same voltage to adjacent sensing lines.

As illustrated in FIG. 7A, the touch data generator 112C includes a plurality of amplifiers (first amplifiers) connected to each of a plurality of sensing lines (for example, the first sensing line SL1 to the third sensing line SL3). (AMP1) to third amplifiers (AMP3)), and each amplifier senses a change in capacitance of a corresponding sensing unit and generates corresponding sensing signals Vout1 to Vout3. The capacitors Cf1 to Cf3 and the resistors Rf1 to Rf3 may be connected in parallel between the first input terminal (−input terminal) and the output terminal of each of the first to third amplifiers AMP1 to AMP3.

In addition, an input signal Vin having a predetermined frequency is commonly provided to the second input terminal (+ input terminal) of the first to third amplifiers AMP1 to AMP3. As the first to third amplifiers AMP1 to AMP3 are connected to the first sensing line SL1 to the third sensing line SL3, the first to third amplifiers AMP1 to AMP3 sense a change in capacitance value of the corresponding sensing line, and correspondingly. The sensing signals Vout1 to Vout3 are output. The horizontal parasitic capacitance components Ch1 to Ch3 shown represent capacitance components generated between each sensing line.

The operation of the touch data generator 112C will be described below in consideration of the case in which the sensing operation is performed on the second sensing line SL2. As the first input terminal (−input terminal) of the second amplifier AMP2 is connected to the second sensing line SL2, the output signal Vout2 corresponding to the capacitance value of the sensing unit is generated. In addition, the second input terminal (+ input terminal) of the first amplifier AMP1 and the third amplifier AMP3 is provided with the same input signal Vin as the signal provided to the second amplifier AMP2. Since the first input terminal (− input terminal) of each of the first amplifier AMP1 and the third amplifier AMP3 follows the voltage level of the second input terminal (+ input terminal), the first amplifier AMP1 and the third amplifier AMP3. The voltages of the first sensing line SL1 and the third sensing line SL3 connected to the first input terminal (−input terminal) of the second side may correspond to the voltage of the second sensing line SL2. Accordingly, since the voltage levels of the sensing lines adjacent to each other are the same or similar, as shown in FIG. 6B, the influence of the horizontal capacitance component of the sensing signal is reduced.

FIG. 7B illustrates a circuit designed to perform an operation similar to the touch data generator 112C of FIG. 7A, and illustrates a case in which one amplifier AMP is shared by the plurality of sensing lines SL1 to SL3. The touch data generator 112D of FIG. 7B may include the sensing lines SL1 to SL3 so that the plurality of sensing lines SL1 to SL3 may be selectively connected to the first input terminal (− input terminal) of the amplifier AMP. And switches SW1 to SW3 for switching the connection between the first input terminal (−input terminal) of the amplifier AMP.

When the sensing operation is performed on the second sensing line SL2, the second switch SW2 connects the second sensing line SL2 to the first input terminal (−input terminal) of the amplifier AMP by a switching operation. Be sure to In addition, the first switch SW1 of the first sensing line SL1 adjacent to the second sensing line SL2 is connected to the line for transmitting the input signal Vin to the first sensing line SL1 by a switching operation. To be connected. In addition, the third switch SW3 of the third sensing line SL3 adjacent to the second sensing line SL2 is also connected to the third sensing line SL3 by a switching operation to a line transmitting the input signal Vin. To be connected.

By the above operation, the amplifier AMP detects the capacitance value of the sensing unit through the second sensing line SL2 and outputs the sensing signal Vout accordingly. On the other hand, since the input signal Vin is provided to the first sensing line SL1 and the third sensing line SL3 adjacent to the second sensing line SL2, the voltage of the second sensing line SL2 is adjacent to the voltage of the second sensing line SL2. The voltages of the first sensing line SL1 and the third sensing line SL3 are the same. As a result, the influence of the horizontal parasitic capacitance component Ch2 may be reduced, and the sensing sensitivity of the touch operation may be improved.

8 and 9 are circuit diagrams illustrating still another embodiment of the touch data generator of FIG. 3. 8 and 9, an additional capacitor for canceling the parasitic capacitance component present in the sensing unit SU is further provided in the touch data generator. By the above configuration, the sensing sensitivity can be improved by removing the horizontal and vertical parasitic capacitance components present in the sensing unit SU.

As illustrated in FIG. 8, the touch data generator 212A includes an amplifier AMP having a first input terminal (− input terminal) connected to a sensing line and a second input terminal (+ input terminal) connected to an input signal Vin. It is provided. In addition, a first capacitor Cf and a resistor Rf disposed in parallel may be connected between the first input terminal and the output terminal of the amplifier AMP.

The touch data generator 212A may further include a second capacitor Cq connected to the sensing line and having a predetermined capacitance. The first electrode of the second capacitor Cq is connected to the sensing line, and a predetermined voltage signal Vq is provided to the second electrode of the second capacitor Cq. Preferably, the parasitic capacitance component Ct in which the charge polarity induced in the second capacitor Cq is present in the sensing unit SU by adjusting the capacitance of the second capacitor Cq and the voltage signal Vq. It is intended to have a polarity opposite to the charge induced in the. For example, when the polarity of the charge induced in the parasitic capacitor provides a positive polarity (+ polarity) to the sensing line, the polarity of the charge induced in the first electrode of the second capacitor Cq is negative polarity (−). Polarity). In addition, it is preferable that the voltage signal Vq provided to the second electrode of the second capacitor Cq is synchronized with the input signal Vin provided to the second input terminal of the amplifier. In this case, the voltage signal Vq is Can be defined as an xVin value. The equation representing the gain of the amplifier AMP is as follows.

When the gain in the high frequency band is obtained from the above equation, the following equation (2) is obtained.

As mentioned above, by adjusting the capacitance value of the second capacitor Cq and the level (value of x) of the voltage signal Vq, the xCq value may be equal to or similar to the value of Cf + Ct + Cq. In the same case, since the value of Cf + Ct + Cq and the value of xCq cancel each other in Equation 2, the gain of the amplifier AMP may be ΔC / Cf. In addition, if the values are not the same, the sensing sensitivity is further improved. That is, by adjusting the values of x and Cq, it is possible to reduce the influence of the gain of the amplifier AMP due to the parasitic capacitance component Ct, and thereby to sense the sensing sensitivity of the capacitance change ΔC due to the touch operation. Can be improved.

Meanwhile, FIG. 9 illustrates the touch data generator 212B for reducing the influence of the sensing line when the sensing line is affected by the change in the voltage provided to the display panel. For example, when the touch screen panel is applied to a mobile liquid crystal display device, interference may occur due to an alternating operation of the voltage VCOM provided to the upper electrode of the display panel.

A vertical capacitance component is generated between the sensing line and the display panel, and the vertical capacitance component affects the output of the amplifier AMP as the upper electrode voltage VCOM provided to the display panel alternates. In order to reduce the effect, the input signal Vin provided to the second input terminal of the amplifier AMP is synchronized with the upper electrode voltage VCOM. If the swing width of the voltage of the input signal Vin is set to be smaller than the swing width of the upper electrode voltage VCOM, when the level of the input signal Vin is high, the upper plate of the vertical parasitic capacitor (eg, sensing Negative charges are collected in the electrode connected to the line. In this case, by appropriately adjusting the capacitance value of the second capacitor Cq and the voltage signal Vq, a positive charge equal to or similar to a negative charge of the vertical parasitic capacitor is negative. 2 Gather on the top of the capacitor (Cq). Accordingly, the influence of the output of the amplifier AMP due to the variation of the vertical capacitance component and the upper electrode voltage VCOM can be eliminated or reduced.

If the input signal Vin and the voltage signal Vq are each a signal synchronized with the upper electrode voltage VCOM, the upper electrode voltage VCOM may be represented by xVin, and the voltage signal Vq may be represented by yVin. have. In this case, the gain of the amplifier AMP shown in FIG. 9 is as shown in Equation 3.

When the gain in the high frequency band is obtained from the above equation, the following equation (4) is obtained.

As described in Equation 4 above, by adjusting the capacitance value of the second capacitor Cq and the level (value of y) of the voltage signal Vq, the influence by the variation of the upper electrode voltage VCOM is reduced. Can be. For example, since the upper electrode voltage VCOM has a predetermined level, the capacitance value of the second capacitor Cq and the level (value of y) of the voltage signal Vq are adjusted to adjust Cf + (1-x) Cv + ( By canceling or reducing the value of 1-y) Cq, it is possible to eliminate or reduce the influence of the output due to the variation of the top electrode voltage VCOM.

FIG. 10 is a circuit diagram illustrating still another embodiment of the touch data generator of FIG. 3. The touch data generator 312 illustrated in FIG. 10 includes all the features of the touch data generator illustrated in FIGS. 6A and 9, thereby effectively reducing the horizontal and vertical parasitic capacitance components generated in the sensing unit. You can. On the other hand, although not shown in detail, in order to effectively reduce the horizontal parasitic capacitance component of the sensing unit, a specific connection relationship of the circuit as shown in Figure 7a and 7b can be applied to the embodiment of FIG.

As illustrated, the parasitic capacitance component generated in the sensing unit SU may include a horizontal parasitic capacitance component Ch and a vertical parasitic capacitance component Cv. In order to reduce the horizontal parasitic capacitance component Ch generated between the sensing lines, the voltage of the sensing line on which the sensing operation is performed and the voltage of the sensing line adjacent to the sensing line on which the sensing operation is performed are equal to each other. To this end, in addition to the amplifier AMP that actually performs a sensing operation on a predetermined sensing line, the input voltage Vin is also provided to a second input terminal of the amplifier AMP corresponding to the sensing line adjacent thereto. Accordingly, since the sensing lines adjacent to each other have the same voltage, the influence on the amplifier AMP by the horizontal capacitance component Ch can be reduced. In FIG. 10, one electrode of the horizontal parasitic capacitor is illustrated as being directly connected to the second input terminal of the amplifier AMP connected to the same sensing line, but the present invention is not limited thereto. One electrode of the horizontal parasitic capacitor may be electrically connected to a first input terminal or a second input terminal of an amplifier AMP connected to an adjacent sensing line.

11 is a block diagram illustrating an example of a display apparatus according to an exemplary embodiment. The display device 400 of FIG. 11 illustrates a mobile liquid crystal display device as an example. The display device 400 includes a touch screen panel 410 for performing a touch screen function and a display panel 420 for implementing an image. In addition, the display apparatus 400 is connected to the touch screen panel 410 to control the touch screen operation (T / C) as a whole, and the timing controller (TCON) for controlling the image implementation of the display panel 420 And a display driving circuit 430 including a gate driver G / D, a source driver S / D, and the like.

As illustrated in FIG. 11, a controller T / C for sensing a signal of the touch screen panel 410 and controlling a touch screen operation and a driving circuit TCON and G / D for driving the display panel 420. And S / D, etc.) may be integrated into one chip and designed. According to an embodiment of the present invention, the touch controller T / C receives at least one timing signal from a timing controller TCON included in a driving circuit block for driving the display panel 420. That is, the driving circuit block transmits and receives a signal with a host controller (not shown) disposed on the main board 440 through a predetermined flexible printed circuit board (FPCB), and the touch controller T / C is connected to the driving circuit block. The integrated design of the chip may receive at least one timing information from the timing controller TCON through a wiring inside the chip. This is because the timing information is transmitted through the flexible printed circuit board (FPCB) when the touch screen controller (T / C) and the driving circuit block are implemented with different chips. Can be reduced.

12 illustrates an example in which the touch controller T / C according to the present invention is applied to a general liquid crystal display device. The liquid crystal display apparatus 500 may include a timing controller 510 for controlling an overall timing for displaying an image, and a voltage generator 520 for generating various voltages required to drive the display apparatus. In addition, the liquid crystal display apparatus 500 may include one or more gate drivers 530 for driving the gate lines of the display panel 550, and one or more source drivers 540 for driving the source lines. The touch controller T / C according to an exemplary embodiment of the present invention may receive timing information from the timing controller 510. Accordingly, each gate driver 530 or each source driver 540 is preferably provided. It may be provided in. 12 shows an example in which a touch controller T / C is provided in each source driver 540. The timing information provided from the timing controller 510 to the source driver 540 may be simultaneously provided to the touch screen controller T / C provided in the source driver 540. The touch screen 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 550, and may store predetermined timing information provided by the timing controller 510. To generate touch data. 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.

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

4A and 4B are waveform diagrams illustrating timings of generating control signals of FIG. 3.

5A is a circuit diagram illustrating an example of an implementation of the touch data generator of FIG. 3, and FIG. 5B is a graph illustrating filtering characteristics of the amplifier of FIG. 5A.

6A is a circuit diagram illustrating another example of the touch data generator of FIG. 3, and FIG. 6B is a graph illustrating filtering characteristics of the amplifier of FIG. 6A.

7A and 7B are detailed circuit diagrams illustrating the touch data generator of FIG. 6A.

8 to 10 are circuit diagrams illustrating still another embodiment of the touch data generator of FIG. 3.

11 is a block diagram illustrating an example of a display apparatus according to an exemplary embodiment.

12 is a block diagram illustrating an example of a display apparatus according to another exemplary embodiment.

  Explanation of symbols on the main parts of the drawings

110: touch screen 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 (25)

A touch data generator connected to a plurality of sensing lines to sense a change in capacitance of a sensing unit disposed on the sensing line, and to process touch signals according to the sensing result to generate touch data; And Receives at least one timing information from a timing controller for driving a display panel, and provides any one of the received timing information and a signal generated in response to the timing information as a control signal to the touch data generator to provide the touch data. And a signal processor for controlling the timing of generation of the signal. The signal processor of claim 1, wherein the signal processor comprises: Receiving at least one of an information signal, a vertical synchronizing signal, and a horizontal synchronizing signal for controlling a change in the voltage of the upper electrode of the display panel as the timing information, and generating the control signal in response to the timing information. Touch controller. The touch data generating unit of claim 1, wherein the touch data generating unit comprises: A sensing signal generator connected to the sensing line and configured to generate a sensing signal whose voltage level varies in response to a change in capacitance of the sensing unit disposed in the sensing line; And And a signal output unit configured to receive the sensing signal from the sensing signal generator and output the received signal in response to the control signal. The method of claim 3, wherein the touch data generating unit, And an analog-to-digital converter for converting the analog output of the signal output unit into a digital signal to generate the touch data. The method of claim 3, The sensing signal generator includes at least one amplifier, And the amplifier comprises a capacitor connected between the first input terminal and the output terminal, wherein the first input terminal is connected to the sensing line and the second input terminal is connected to the input signal having the first frequency. A sensing signal generator including at least one amplifier, sensing a change in capacitance of a sensing unit disposed in a plurality of sensing lines by using the at least one amplifier, and processing a sensing signal generated based on the sensing result A touch data generator for generating touch data; And A signal processor for controlling an operation of the touch data generator; Each of the at least one amplifier has a first input connected to the sensing line and a second input connected to an input signal having a first frequency, and outputting a signal based on a gain of the amplifier as the sensing signal. Touch controller, characterized in that. The method of claim 6, wherein the sensing signal generator, A first amplifier connected to a first input line, a second input terminal to the input signal, and a capacitor connected between the first input terminal and the output terminal; And transmitting the received input signal to a second sensing line adjacent to the first sensing line, thereby reducing parasitic capacitance components of the first sensing line and the second sensing line. The method of claim 6, The at least one amplifier is composed of a plurality of amplifiers, each connected to a plurality of sensing lines, Each first input terminal of the plurality of amplifiers is connected to each of the plurality of sensing lines, and the second input terminal of the plurality of amplifiers is commonly connected to the input signal. By the amplification operation of the first amplifier connected to the first sensing line and the amplification operation of the second amplifier connected to the second sensing line adjacent to the first sensing line, the first sensing line and the second sensing line. Touch controller, characterized in that the same level of voltage is applied. The method of claim 6, wherein the amplifier, A second input terminal connected switchably with a plurality of sensing lines, wherein the first sensing line is connected to a first input terminal when the first sensing line is selected, and a second input terminal receiving the input signal is adjacent to the first sensing line; Touch controller, characterized in that connected to the sensing line. The method of claim 6, wherein the sensing signal generator, At least one amplifier comprising a first capacitor; And A second capacitor connected to the at least one amplifier, The amplifier may include a first input terminal connected to the sensing line and a second input terminal connected to a first input signal having a first frequency, and the first capacitor may be connected between the first input terminal and the output terminal. The second capacitor is a touch controller, characterized in that the first electrode is connected to the first input terminal of the amplifier and the second electrode is connected to the second input signal in synchronization with the first input signal. The method of claim 10, The signal processor receives at least one timing information from a timing controller for driving a display panel, The first input signal and the second input signal are synchronized with a frequency of any one of voltage signals provided to the display panel using the at least one timing information. And the polarity of the second capacitor is adjusted to have a polarity opposite to that of the parasitic capacitance component such that the parasitic capacitance component between the sensing unit and the display panel is canceled by the second capacitor. The method of claim 6, wherein the sensing signal generator, At least one amplifier comprising a first capacitor; And A second capacitor connected to the at least one amplifier, The amplifier has a first input terminal connected to the sensing line, a second input terminal connected to a first input signal having a first frequency, and the first capacitor is connected between the first input terminal and the output terminal, The second capacitor may include a first electrode connected to a first input terminal of the amplifier and a second electrode connected to a second input signal synchronized with the first input signal. Each of the first sensing line and the second sensing line adjacent to the first sensing line, in which a sensing operation is performed, is electrically connected to a first input terminal or a second input terminal of the at least one amplifier, and thus, the first sensing line and the first sensing line. And the same level of voltage is applied to the second sensing line. The method of claim 6, wherein the touch data generating unit, Receiving a control signal generated using at least one timing information from a timing controller for driving a display panel, A signal output unit which receives the sensing signal from the sensing signal generator and outputs the received signal in response to the control signal; And And an analog-to-digital converter for converting the analog output of the signal output unit into a digital signal to generate the touch data. At least one amplifier for sensing a change in capacitance of the sensing unit disposed in the plurality of sensing lines and a capacitor connected to the at least one amplifier, respectively, and processes the sensing signal generated based on the sensing result to touch data And a touch data generator for generating a Each of the at least one amplifier has a first input connected to a corresponding sensing line and a second input connected to an input signal having a first frequency. The capacitor has a first electrode connected to a first input terminal of the amplifier and a second electrode connected to a second input signal synchronized with the first input signal. And the first input signal and the second input signal are synchronized with one of the voltages provided to the display panel. At least one amplifier connected to the sensing unit through a sensing line to sense a change in capacitance of the sensing unit having a variable capacitance value corresponding to a touch operation, Each of the at least one amplifier includes a first capacitor having a first input terminal connected to the sensing line, a second input terminal connected to a first input signal having a first frequency, and connected between the first input terminal and the output terminal. , The amplifier performs a filtering operation having a predetermined pass band, wherein the first frequency has a frequency value within the pass band, and generates an output signal having a gain reflecting a change in capacitance of the sensing unit as a sensing signal. Sensing signal generator, characterized in that. The method of claim 15, In a sensing operation through a first sensing line, the first input terminal or the second input terminal of any one of the at least one amplifiers is electrically connected to a second sensing line adjacent to the first sensing line. The sensing signal generating device, characterized in that for providing the same level of voltage to the sensing line and the second sensing line. The method of claim 15, And a second capacitor having a first electrode connected to a first input terminal of the amplifier and a second electrode connected to a second input signal synchronized with the first input signal. A display panel driving circuit unit including a timing controller generating at least one timing information for driving the display panel; And A touch controller configured to sense a touch operation on the touch screen panel, to generate a sensing signal by sensing a change in capacitance of the sensing unit included in the touch screen panel, and to process the sensing signal, The touch controller unit, A touch data generator for sensing a change in capacitance of the sensing unit through a sensing line to generate a sensing signal, and processing the sensing signal to generate touch data; And The timing information is received from the timing controller, and one of the generated timing information and a signal generated in response to the timing information is provided to the touch data generator as a control signal to control the timing of generation of the touch data. Display driving circuit comprising a signal processor. The method of claim 18, wherein the touch data generating unit, At least one amplifier, the amplifier having a first input coupled to the sensing line and a second input coupled to a first input signal having a first frequency, the first coupled between the first input and the output; A sensing signal generator including a capacitor; And And a signal output unit configured to receive the sensing signal from the sensing signal generator and to output the received signal in response to the control signal. The method of claim 19, A first amplifier of the at least one amplifier has a first input terminal is connected to the first sensing line and the second input terminal is connected to the input signal, The touch data generator may transmit the received first input signal to a second sensing line adjacent to the first sensing line to reduce a parasitic capacitance component between the first sensing line and the second sensing line. Display drive circuit characterized in that. The method of claim 19, wherein the sensing signal generator, A second capacitor connected to a first input terminal of the amplifier and a second electrode connected to a second input signal synchronized with the first input signal; Wherein the polarity of the second capacitor is adjusted to have a polarity opposite to that of the parasitic capacitance component such that the parasitic capacitance component between the sensing unit and the display panel is canceled by the second capacitor. . The method of claim 20, And the first input signal and the second input signal are synchronized with a frequency of any one of voltages provided to the display panel. A display panel for implementing an image corresponding to the received image data; A touch screen panel including a plurality of sensing units, each sensing unit having a variable capacitance value corresponding to a touch operation; A display panel driving circuit unit connected to the display panel to drive the display panel and including a timing controller configured to generate timing information related to a display operation; And A touch controller unit connected to the touch screen panel to sense a touch operation on the touch screen panel, processing a signal according to a sensing result to generate touch data, and controlling a timing of generation of the touch data in response to the timing information Display device comprising a. 24. The method of claim 23, And the display panel driver circuit part and the touch controller part are integrated in the same semiconductor chip. 24. The method of claim 23, The touch controller unit is provided in at least one of a gate driver and a source driver disposed in the display panel driver circuit unit.

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