KR101951942B1 - Touch sensing apparatus - Google Patents

Abstract

The present invention relates to a touch sensing device capable of eliminating high frequency noise, which includes touch driving lines and touch sensing lines crossing the touch driving lines; A touch driving line driving circuit for supplying a plurality of touch driving pulses having a high potential voltage and a low potential voltage to the touch driving lines; And a touch sensing line driving circuit for dividing and sampling the signals received through the touch sensing lines within a period of the touch driving pulse a plurality of times, and the touch sensing line driving circuit converts the signals received from the touch sensing lines A sampler for sequentially sampling and storing the first and second signals in each of divided periods in which the high potential voltage interval of the touch driving pulse is equally divided by 1 / M (M is a natural number of 2 or more); And an integrator for sequentially integrating the first and second signals sampled by the sampler for each division period in which the low potential voltage interval of the touch driving pulse is evenly divided by 1 / M.

Description

{TOUCH SENSING APPARATUS}

The present invention relates to a touch sensing apparatus, and more particularly, to a touch sensing apparatus capable of effectively removing high frequency noise.

A user interface (UI) enables communication between a person (user) and various electric or electronic devices, allowing a user to easily control the device as desired. Representative examples of such a user interface include a keypad, a keyboard, a mouse, an on screen display (OSD), a remote controller having infrared communication or radio frequency (RF) communication function, and the like. User interface technology has been developed to enhance the user's sensibility and ease of operation. Recently, a user interface (UI) has evolved into a touch UI, a voice recognition UI, a 3D UI, and the like.

Touch UI is becoming a necessity for portable information devices and is being applied to household appliances. As an example of a touch sensing device for implementing a touch UI, a mutual capacitance type touch sensing device capable of sensing proximity and sensing multi-touch (or proximity) as well as a touch has been spotlighted.

The touch sensing device includes a touch sensing electrode line and a touch sensing electrode line intersecting each other to form a matrix, a driving voltage is applied to the touch sensing electrode line, a touch sensing electrode line, Sensing the change of the charged voltage in the sensing nodes defined as the intersection points of the sensing electrode lines, and detecting whether or not the touch is made and the touch coordinates.

Conventionally, for such touch and touch coordinate detection, an output voltage output through a touch sensing electrode line is sampled, and a change amount of a charge accumulated in a mutual capacitance of the sensing node is converted into a voltage change, Various methods have been used, for example, by comparing a voltage change amount with a predetermined threshold voltage or by counting.

In order to reduce the influence of noise mixed in the touch sensor in a touch sensing apparatus of a mutual capacitive type, a DC offset (DC) included in the sensed output voltage using a digital to analog converter (DAC) offset). In the mutual capacitance type touch sensing apparatus, noise includes high frequency noise, DC offset, and interference between touch driving lines and touch sensing lines. This noise lowers the signal-to-noise ratio (SNR) of the signal read from the sensing nodes, thereby lowering the sensitivity of the touch sensing device. In particular, since the high frequency noise is often used in combination with other devices such as a display device, rather than being used independently, a need has arisen for improving the signal-to-noise ratio by eliminating the high-frequency noise generated therefrom.

SUMMARY OF THE INVENTION The present invention has been made in order to solve the above-mentioned problems, and it is an object of the present invention to provide a signal transmission apparatus and a method thereof, which are capable of transmitting signal transmission paths of first and second input signals received through touch sensing lines, Noise ratio (SNR) by removing high frequency noise components included in the touch sensing device.

The touch sensing device of the present invention includes touch driving lines and touch sensing lines intersecting with the touch driving lines. The touch sensing device includes a touch driving pulse having a high potential and a low potential, A touch driving line driving circuit for supplying a plurality of times of driving signals; And a touch sensing line driving circuit for dividing and sampling signals received through the touch sensing lines within a period of the touch driving pulse a plurality of times, wherein the touch sensing line driving circuit receives the touch sensing lines from the touch sensing lines A sampler for sequentially sampling and storing the first and second signals in order during each divided period in which the high potential voltage section of the touch driving pulse is equally divided by 1 / M (M is a natural number of 2 or more); And an integrator for sequentially integrating the first and second signals sampled by the sampler for each division period in which the low potential voltage interval of the touch driving pulse is evenly divided by 1 / M.

The sampler may further include first and second input terminals and first and second output terminals; A plurality of first sampling capacitors connected in parallel between the first input terminal and the first output terminal; A plurality of first sampling switches connected between the first input terminal and the first electrodes of the plurality of first sampling capacitors, respectively; A plurality of second sampling switches respectively connected between the second electrodes of the plurality of first sampling capacitors and the first output terminal; A plurality of third sampling switches respectively connected between the first electrodes of the plurality of first sampling capacitors and the node between the plurality of first sampling switches and the ground; A plurality of fourth sampling switches respectively connected between the second electrodes of the plurality of first sampling capacitors and a node between the plurality of second sampling switches and the ground; And a fifth sampling switch connected between the first input terminal and a node between the plurality of first sampling switches and ground.

The sampler may further include: a plurality of second sampling capacitors connected in parallel between the second input terminal and the second output terminal; A plurality of sixth sampling switches connected between the second input terminal and the first electrodes of the plurality of second sampling capacitors, respectively; A plurality of seventh sampling switches connected between the second electrodes of the plurality of second sampling capacitors and the second output terminal, respectively; A plurality of eighth sampling switches each connected between a node between the first electrodes of the plurality of second sampling capacitors and the plurality of sixth sampling switches, and a ground; A plurality of ninth sampling switches respectively connected between the second electrodes of the plurality of second sampling capacitors and the node between the seventh sampling switches and ground; And a tenth sampling switch connected between the node between the second input terminal and the plurality of sixth sampling switches and the ground.

The integrator may further include: a first integrating capacitor for sequentially accumulating the sampling voltages stored in the first sampling capacitors during each division period in which the low potential voltage section of the touch driving pulse is equally divided by 1 / M; A second integration capacitor for sequentially accumulating the sampling voltages stored in the second sampling capacitors during each division period in which the low potential voltage section of the touch driving pulse is equally divided by 1 / M; And a differential amplifier connected to the integrating capacitors, wherein the first integrating capacitor is connected between a first input terminal and a first output terminal of the differential amplifier, and the second integrating capacitor is connected to a second input of the differential amplifier Terminal and the second output terminal.

Also, the first sampling switches, the fourth sampling switches, the sixth sampling switches, and the ninth sampling switches are sequentially arranged for each division period in which the high potential voltage interval of the touch driving pulse is equally divided by 1 / M And the second sampling switches, the third sampling switches, the seventh sampling switches, and the eighth sampling switches are turned on in each division period in which the low potential voltage section of the touch driving pulse is equally divided by 1 / M Lt; / RTI >

In addition, the fifth sampling switch and the tenth sampling switch are turned on during the low potential voltage period of the touch driving pulse.

The present invention relates to a method and an apparatus for sequentially switching a signal transmission path of first and second input signals received through touch sensing lines using a plurality of sampling capacitors and a plurality of sampling switches, The noise component can be removed. Therefore, the signal-to-noise ratio (SNR) can be improved and the touch sensitivity can be increased.

1 is a block diagram showing a touch sensing apparatus according to an embodiment of the present invention.
2 is a view schematically showing an example in which a touch sensing device according to an embodiment of the present invention is attached to an upper substrate of a display panel,
3 is a schematic view illustrating an example in which a touch sensing device according to an embodiment of the present invention is integrally formed on an upper substrate of a display panel,
4 is a schematic view illustrating an example in which a touch sensing apparatus according to an embodiment of the present invention is formed on a lower substrate of a display panel,
5 is a circuit diagram showing an example of a touch sensing line driving circuit of a touch sensing apparatus according to an embodiment of the present invention.
6 is a circuit diagram showing another example of the touch sensing line driving circuit of the touch sensing device according to the embodiment of the present invention,
7 is a circuit diagram specifically showing a touch sensing line driving circuit of the touch sensing device according to the embodiment of the present invention,
8A is a circuit diagram for explaining the sampling operation of the touch sensing line driving circuit shown in FIG. 7,
8B is a circuit diagram for explaining an integrating operation of the touch sensing line driving circuit shown in FIG. 7,
9 is a waveform diagram showing an example of driving pulses supplied to the touch driving lines of the touch sensing apparatus according to the embodiment of the present invention,
10 is a waveform diagram showing control pulses supplied to the sampler and drive pulses supplied to the touch driving lines of the touch sensing apparatus according to the embodiment of the present invention,
11 is a waveform diagram for explaining reduction of high frequency noise by the touch sensing apparatus according to the embodiment of the present invention.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Reference will now be made in detail to the preferred embodiments of the present invention, examples of which are illustrated in the accompanying drawings. Like reference numerals throughout the specification denote substantially identical components. The term "line" in the touch driving line and the touch sensing line used in the present specification does not simply mean a straight line, but may be a bar type, a triangle, a diamond, a honeycomb, A plurality of electrodes having a specific shape such as an ellipse, an ellipse, or a combined shape thereof are connected to each other and formed in a line.

1 to 4, a display device according to an exemplary embodiment of the present invention includes a display panel DIS, display driving circuits 12, 14 and 20, a display timing controller 20, a touch sensing device (TSP) Touch sensing device driving circuits 32, 34, and 36, a touch coordinate calculation unit 30, and the like.

The display device of the present invention can be applied to a liquid crystal display (LCD), a field emission display (FED), a plasma display panel (PDP), an organic light emitting display , OLED), and electrophoresis (EPD). Hereinafter, the liquid crystal display device will be described as an example of the display device, but it should be noted that the display device of the present invention is not limited to the liquid crystal display device.

The display panel (DIS) has a liquid crystal layer formed between two substrates. A plurality of gate lines G1 to Gn, n being a natural number) intersecting the data lines D1 to Dm and m are natural numbers and the data lines D1 to Dm are formed on the lower substrate of the display panel DIS, A plurality of thin film transistors (TFTs) formed at intersections of the data lines D1 to Dm and the gate lines G1 to Gn, a plurality of pixel electrodes A storage capacitor connected to the pixel electrode to maintain the voltage of the liquid crystal cell, and the like.

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

The upper substrate GLS1 of the display panel DIS may include a black matrix, a color filter, and the like. The lower substrate GLS2 of the display panel DIS may be implemented as a COT (Color Filter On TFT) structure. In this case, the black matrix and the color filter can be formed on the lower substrate of the display panel DIS.

Polarizing plates POL1 and POL2 are attached to the upper substrate GLS1 and the lower substrate GLS2 of the display panel DIS and an alignment film for setting the pretilt angle of the liquid crystal on the inner surface in contact with the liquid crystal is formed. A column spacer for maintaining a cell gap of the liquid crystal cell is formed between the upper substrate GLS1 and the lower substrate GLS2 of the display panel DIS.

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

The display driving circuit includes a data driving circuit 12, a scan driving circuit 14, and a display timing controller 20, and writes the video data voltage of the input image to the pixels of the display panel DIS. The data driving circuit 12 converts the digital video data RGB input from the display timing controller 20 into an analog positive / negative gamma compensation voltage to output a data voltage. The data voltage output from the data driving circuit 12 is supplied to the data lines D1 to Dm. The scan driving circuit 14 sequentially supplies the gate pulse (or scan pulse) synchronized with the data voltage to the gate lines G1 to Gn so that the data line of the display panel DIS to which the data voltage is written is selected .

The display timing controller 20 inputs a timing signal such as a vertical synchronization signal Vsync, a horizontal synchronization signal Hsync, a data enable signal DE and a main clock MCLK input from an external host system And generates a scan timing control signal and a data timing control signal for controlling the operation timings of the data driving circuit 12 and the scan driving circuit 14. The scan timing control signal includes a gate start pulse (GSP), a gate shift clock, a gate output enable signal (GOE), and the like. The data timing control signal includes a source sampling clock (SSC), a polarity control signal (Polarity), a source output enable signal (SOE), and the like.

The touch sensing device TSP may be bonded on the upper polarizer POL1 of the display panel DIS as shown in FIG. 2 or may be formed between the upper polarizer POL1 and the upper substrate GLS1 as shown in FIG. The touch sensing device TSP may be formed on the lower substrate GLS2 as an in-cell type together with the pixel array in the display panel DIS as shown in FIG. 4 .

The touch sensing device TSP includes touch sensing lines R1 to Ri and i to m intersecting the touch driving lines T1 to Tj and j being positive integers smaller than n and the touch driving lines T1 to Tj, And i x j sensing nodes formed at the intersections of the touch driving lines T1 to Tj and the touch sensing lines R1 to Ri. Hereinafter, such sensing nodes are referred to as touch sensors, and each touch sensor TSN is formed with mutual capacitance by the touch driving lines T1 to Tj and the touch sensing lines R1 to Ri.

The touch sensing device driving circuits 32, 34, and 36 apply a touch driving pulse to the touch driving lines T1 to Tj and sample the output voltage output through the touch sensing line within one cycle of the touch driving pulse Integrals are performed sequentially. To this end, the touch sensing device driving circuit includes a touch driving line driving circuit 32, a touch sensing line driving circuit 34, and a touch sensing timing controller 36. The touch driving line driving circuit 32, the touch sensing line driving circuit 34, and the touch sensing timing controller 36 may be integrated in one ROIC (Read-out IC). The touch coordinate calculation unit 30 may also be integrated into the ROIC.

The touch driving lines T1 to Tj are connected to the touch driving channels of the touch driving line driving circuit 32. [ The touch driving line driving circuit 32 selects a touch driving channel to output a touch driving pulse in response to the touch driving setup signal Tset input from the touch sensing timing controller 36, The touch driving pulse is applied to the lines T1 to Tj. The touch driving lines T1 to Tj are charged during the high potential interval of the touch driving pulse to supply the electric charges to the touch sensors TSN and are discharged in the low potential interval of the touch driving pulse. As shown in FIG. 7, the touch driving pulse is divided into N (N is a positive integer of 2 or more) consecutive times in each of the touch driving lines T1 to Tj so that the touch sensor output voltage can be accumulated in the integrator through the touch sensing channel .

The touch sensing lines R1 to Ri are connected to the touch sensing channels of the touch sensing line driving circuit 34. [ The touch sensing line drive circuit 34 selects a touch sensing channel to receive the output voltage of the touch sensor TSN in response to the touch sensing setup signal Rset input from the touch sensing timing controller 36. The touch sensing line driving circuit 34 samples the signals received through the touch sensing channels every one cycle of the touch driving pulse and accumulates them in an integrator.

The touch sensing line drive circuit 34 converts the voltage accumulated in the integrator into digital data (Tdata) at predetermined time intervals using an analog-to-digital converter (ADC) connected to the output terminal of the integrator do. The touch sensing line drive circuit 34 supplies the digital data (Tdata) to the touch coordinate calculation unit 30 as touch raw data.

The touch sensing timing controller 36 generates a touch driving signal Tset for setting a touch driving channel for outputting a touch driving pulse in the touch driving line driving circuit 32 and a touch driving signal And generates a touch sensing setup signal Rset for setting a touch sensing channel to receive the voltage. In addition, the touch sensing timing controller 36 generates timing control signals for controlling the operation timing of the touch driving line driving circuit 32 and the touch sensing line driving circuit 34.

The touch coordinate calculation unit 30 compares the digital data (Tdata) received from the touch sensing line drive circuit 34 with a preset threshold value and judges the data above the threshold value as touch data obtained from the touch sensors at the actual touch input position do. The touch coordinate calculation unit 30 assigns an identification code (ID) to each of the touch inputs, and analyzes the touch data using a preset touch recognition algorithm to calculate coordinates of each of the touch inputs. The touch coordinate calculation unit 30 transmits touch map data Txy including coordinates of each of the touch inputs to the host system. The touch coordinate calculation unit 30 may be implemented as an MCU (Micro Controller Unit).

The host system may be implemented by any one of a navigation system, a set-top box, a DVD player, a Blu-ray player, a personal computer (PC), a home theater system, a broadcast receiver, and a phone system. The host system includes a system on chip (SoC) with a built-in scaler, and converts the image data into a format suitable for display on a display panel (DIS). In addition, the host system executes an application program associated with coordinate values of each of the touch inputs input from the touch coordinate calculation unit 30. [

FIG. 5 is a circuit diagram showing an example of a touch sensing electrode line driving circuit of the touch sensing device according to the embodiment of the present invention, FIG. 6 is a circuit diagram showing another example of the touch sensing electrode line driving circuit of the touch sensing device according to the embodiment of the present invention, It is a circuit diagram showing an example.

5 and 6, the touch sensing line drive circuit 34 includes a sampler 64, an integrator 66, and an analog-to-digital converter (ADC) 68.

The sampler 64 is connected between the touch sensing lines R1 to Ri and the integrator 66. When the high potential voltage of the touch driving pulse is applied to the touch driving lines T1 to Tj, R1 to Ri and supplies the sampled input signal to the integrator 66 when the voltage of the touch driving lines T1 to Tj is low. The integrator 66 is connected between the sampler 64 and the ADC 68 and integrates the signal received via the sampler 64 during the low potential section of the touch drive pulse. The ADC 68 is connected to the output terminal of the integrator 66 and converts the output voltage from the integrator 66 into digital data Tdata and transmits it to the touch coordinate calculator 30.

A differential amplifier 62, which is a preamplifier, may be provided between the touch sensing lines R1 to Ri and the sampler 64 as shown in FIG. The differential amplifier 62 amplifies the difference between the signals input through the neighboring touch sensing lines and outputs the difference voltage. The differential amplifier 62 amplifies the difference between the signals input through the neighboring touch sensing lines R1 to Ri to reduce the noise components due to the parasitic capacitance of the touch sensing device TSP, ) Can be improved. The differential amplifier 62 amplifies the difference between the voltages obtained from the touch sensors neighboring along the direction of the touch driving line through the positive output terminal and the negative output terminal to generate a complementary positive signal and a negative signal voltage And can be implemented as a fully-deflecting amplifier that outputs a signal.

7 is a circuit diagram specifically showing an internal configuration of the sampler 64 and the integrator 66 of the touch sensing line drive circuit 34. As shown in Fig. 7, the sampler 64, the integrator 66 and the ADC 68 are each shown to be one, but this depends on the number of touch sensing lines, for example, in the embodiment of FIG. 5, / 2 in the case of FIG. 6, and (i-1) / 2 in the case of the embodiment of FIG.

Referring to FIG. 7, the sampler 64 includes first and second input terminals and first and second output terminals. The sampler 64 further includes first sampling switches Sa, S11, S12, S13, S14, S21, S22, S23, S24 and S31 for switching the signal transmission path between the first input terminal and the first output terminal. Cs12, Cs13, and Cs14, and a signal transmission path between the second input terminal and the second output terminal is represented by: S32, S33, S34, S41, S42, S43, The second sampling switches Sb, S51, S52, S53, S54, S61, S62, S63, S64, S71, S72, S73, S74, S81, S82, S83, (Cs21, Cs22, Cs23, Cs24).

The first sampling capacitors Cs11, Cs12, Cs13, and Cs14 are connected in parallel between the first input terminal and the first output terminal. The first 1-1 sampling switches S11, S12, S13 and S14 are connected between the first sampling capacitors Cs11, Cs12, Cs13 and Cs14 and the first input terminals, respectively. The first sampling capacitors Cs11, And the 1-2 sampling switches S41, S42, S43, and S44 are connected between the first output terminal and the second output terminal. The first sampling capacitors Cs11, Cs12, Cs13 and Cs14 sample and store the first input signal Vin1 and then store the first input signal Vin1 in the first input terminal (-) of the differential amplifier 65 of the integrator 66, Supply.

According to this configuration, a 1-1 node n11 is formed between one ends of the first input terminal and the 1-1 sampling switches S11, S12, S13, and S14, N22, n23, n24 between the other electrodes of the first sampling capacitors S11, S12, S13, and S14 and the first electrodes of the first sampling capacitors S11, S12, S13, And between the second electrodes of the first sampling capacitors Cs11, Cs12, Cs13 and Cs14 and one ends of the first-second sampling switches S41, S42, S43 and S44, The ninth node n41 is formed between the other ends of the first-second sampling switches S41, S42, S43, and S44 and the first output terminal, .

A 1-3 sampling switch Sa is connected between the 1-1 node n11 and ground and a 1 st sampling switch Sa is connected between the 1-2nd node n21, n22, n23, and n24 and ground. The sampling switches S21, S22, S23 and S24 are connected and the 1-2 sampling switches S41, S42, and S42 are connected between the first and third nodes n31, n32, n33, S43, and S44 are connected.

The sampler 64 further includes second sampling switches Sb, S51, S52, S53, S54, S61, S62, S63, S64, S71, and S62 for switching the signal transmission path between the second input terminal and the second output terminal. Cs22, Cs23, and Cs24, and the signal transmission path between the second input terminal and the second output terminal is switched The second sampling capacitors (Sb, S51, S52, S53, S54, S61, S62, S63, S64, S71, S72, S73, S74, S81, S82, S83, Cs21, Cs22, Cs23, Cs24).

The second sampling capacitors Cs21, Cs22, Cs23, and Cs24 are connected in parallel between the second-1 node 51 connected to the second input terminal and the second output terminal. The second-1 sampling switches S51, S52, S53, and S54 are connected between the second sampling capacitors Cs21, Cs22, Cs23, and Cs24 and the second-1 node n51, The second-2 sampling switches S81, S82, S83, and S84 are connected between the second output terminals Cs21, Cs22, Cs23, and Cs24, respectively. The second sampling capacitors Cs21, Cs22, Cs23 and Cs24 sample and store the second input signal Vin2 and then store them in the second input terminal (+) of the differential amplifier 65 of the integrator 66, Supply.

According to this configuration, a 1-1 node n11 is formed between one ends of the first input terminal and the 1-1 sampling switches S11, S12, S13, and S14, N22, n23, and n24 between the first electrodes of the first sampling capacitors Cs11, Cs12, Cs13, and Cs14 and the other ends of the first sampling capacitors S11, S12, S13, and S14, And between the second electrodes of the first sampling capacitors Cs11, Cs12, Cs13 and Cs14 and one ends of the first-second sampling switches S41, S42, S43 and S44, N41 and n34 are formed between the other ends of the first-second sampling switches S41, S42, S43, and S44 and the second output terminal, .

A 1-3 sampling switch Sa is connected between the 1-1 node n11 and ground and a 1 st sampling switch Sa is connected between the 1-2nd node n21, n22, n23, and n24 and ground. 1-4 sampling switches S21, S22, S23 and S24 are connected, and between the first and third nodes n31, n32, n33 and n34 and ground, the first to fifth sampling switches S41, S42, S43, and S44 are connected.

The first and second input signals Vin1 and Vin2 are inputted to the first and second input terminals of the sampler 64 through the touch sensing lines R1 and R2 as shown in FIG. 6, the first and second input signals Vin1 and Vin2 amplified by the differential amplifier 62 are input.

FIG. 9 is a waveform diagram showing an example of a touch driving pulse supplied to the touch driving lines T1 to Tj, and shows an example in which three driving pulses are sequentially supplied to each touch driving line sequentially. 10 is a waveform diagram showing driving pulses supplied to the touch driving lines of the touch sensing apparatus and control signals supplied to the sampler according to the embodiment of the present invention.

5 and 6, the sampler 64 receives the signal of the first and second input signals Vin1 and Vin2 in response to the sampling control signal Csam input from the touch sensing timing controller 36, Switches the transmission path. 10, the sampling control signal Csam is applied to the first 1/4 section of the high potential voltage section of the touch driving pulse T supplied to the touch driving lines T1 to Tj and the first 1/4 section of the low potential voltage section The first sampling control signal Csam1 having the high potential voltage in the first 1/4 interval and the second 1/4 of the high potential voltage interval of the touch driving pulse T supplied to the touch driving lines T1 to Tj The second sampling control signal Csam2 having the high potential voltage in the second 1/4 section of the low potential voltage section and the high potential voltage Vs of the touch driving pulse T supplied to the touch driving lines T1 to Tj, The third sampling control signal Csam3 having a high potential voltage in the third 1/4 section of the low potential voltage section and the third sampling control signal Csam3 having the high potential voltage in the third 1/4 section of the low potential voltage section, (T) having a high potential voltage in the fourth 1/4 section of the high-potential voltage section and the fourth 1/4 section of the low-potential voltage section, A fifth sampling control signal Csam5 having a high potential across the low potential voltage section of the touch driving pulse T, and a fifth sampling control signal Csam5. The number of sampling control signals is determined corresponding to the number of sampling capacitors.

7 and 10, the first sampling control signal Csam1 is supplied to the sampling switches S11, S21, S31, S41, S51, S61, S71 and S81 of the sampler 64, The control signal Csam2 is supplied to the sampling switches S12, S22, S32, S42, S52, S62, S72 and S82 of the sampler 64 and the third sampling control signal Csam3 is supplied to the sampling And the fourth sampling control signal Csam4 is supplied to the sampling switches S14, S24, S34, S44, and S54 of the sampler 64. The sampling switches S13, S23, S33, S43, , S64, S74 and S84 and the fifth sampling control signal Csam5 is supplied to the sampling switches Sa and Sb of the sampler 64, respectively.

7, the integrator 66 includes a differential amplifier 65 connected between the first and second output terminals of the sampler 64 and the ADC 68. The differential amplifier 65 may be implemented as a fully differential amplifier having first and second input terminals and first and second output terminals. A first integrating capacitor Cint1 and a first reset sampling switch Srst1 are connected in parallel between a first input terminal (-) and a first output terminal (+) of the differential amplifier 65. A differential amplifier 65, The second integrating capacitor Cint2 and the second reset sampling switch Srst2 are connected in parallel between the second input terminal (+) and the second output terminal (-). The first and second integral capacitors Cint1 and Cint2 accumulate the voltage sampled by the sampler 64. [ The first and second reset sampling switches Srst1 and Srst2 connect both ends of each of the first and second integrating capacitors in response to a reset pulse supplied from the touch sensing timing controller 36 to reset the capacitors.

Next, sampling and integration operations of the touch sensing line driver circuit according to the embodiment of the present invention will be described with reference to FIGS. 8A, 8B, and 10. FIG.

First, the sampling operation of the touch sensing line driving circuit according to the embodiment of the present invention will be described with reference to FIGS. 8A and 10.

Referring to FIGS. 8A and 10, when the first sampling control signal Csam1 is supplied during the first high-potential voltage period of the high-potential voltage section of the touch driving pulse T, The first -5 sampling switch S31 is turned on so that the 1-1 sampling capacitor Cs11 samples and stores the voltage of the first input signal Vin1 and the 2-1 sampling switch S51 and the 2- 5 sampling switch S71 is turned on so that the 2-1 sampling capacitor Cs21 samples and stores the voltage of the second input signal Vin2.

When the second sampling control signal Csam2 is supplied during the second high potential voltage interval of the high potential voltage interval of the touch driving pulse T, the 1-1 sampling switch S12 and the 1-5 sampling switch S32 are turned on so that the 1-2 sampling capacitor Cs12 samples and stores the voltage of the first input signal Vin1 and the 2-1 sampling switch S52 and the 2-5 sampling switch S72 And the second -2 sampling capacitor Cs22 is turned on to sample and store the voltage of the second input signal Vin2.

When the third sampling control signal Csam3 is supplied during the third high-potential voltage period of the high-potential voltage section of the touch-driving pulse T, the 1-1 sampling switch S13 and the 1-5 sampling switch S33 are turned on so that the 1-3 sampling capacitor Cs13 samples and stores the voltage of the first input signal Vin1 and the 2-1 sampling switch S53 and the 2-5 sampling switch S73 The second sampling capacitor Cs23 samples and stores the voltage of the second input signal Vin2.

When the fourth sampling control signal Csam4 is supplied during the fourth high-potential voltage period of the high-potential voltage section of the touch driving pulse T, the 1-1 sampling switch S14 and the 1-5 sampling switch S34 are turned on so that the 1-2 sampling capacitor Cs14 samples and stores the voltage of the first input signal Vin1 and the 2-1 sampling switch S54 and the 2-5 sampling switch S74 And the second-fourth sampling capacitor Cs24 is turned on to sample and store the voltage of the second input signal Vin2.

If the electrostatic capacitance charged in each of the first to fourth sampling capacitors CS1 to CS4 is C / 4, the 1-1 to 1-4 sampling capacitors CS1 to CS4 are divided into the first And the total capacitance is C because it is connected in parallel between the input terminal and the first output terminal. Similarly, assuming that the capacitance charged in each of the 1-1 to 1-4 sampling capacitors (CS1 to CS4) is C / 4, the 1-1 to 1-4 sampling capacitors (CS1 to CS4) 2 is connected in parallel between the input terminal and the second output terminal, the total capacitance is C.

Next, the integrating operation of the touch sensing line driving circuit according to the embodiment of the present invention will be described with reference to FIG. 8B and FIG.

8B and 10, when the fifth sampling control signal Csam5 is supplied during the low potential voltage period of the touch driving pulse T, the first to third sampling switches Sa and Sb are turned on and the sampler 64 are connected to the ground.

When the first sampling control signal Csam1 is supplied during the first low potential voltage interval of the low potential voltage section of the touch driving pulse T, the 1-1 sampling switch S11 and the 1-5 sampling switch S31 are turned on, The 1-1 sampling switch S21 and the 1-2 sampling switch S41 are turned on so that the 1-1 voltage stored in the 1-1 sampling capacitor Cs11 is applied to the differential amplifier 65 The second -1 sampling switch S51 and the second 2-5 sampling switch S71 are turned off and the second 2-4 sampling switch S61 and the second -2 sampling switch S71 are turned off, The second-1 voltage stored in the second-1 sampling capacitor Cs21 is input to the second input terminal (+) of the differential amplifier 65 because the first-second sampling signal S81 is turned on.

When the second sampling control signal Csam2 is supplied during the second low potential voltage interval of the low potential voltage interval of the touch driving pulse T, the 1-1 sampling switch S12 and the 1-5 sampling switch S32 are turned off and the 1-4 sampling switch S22 and the 1-5 sampling switch S42 are turned on so that the 1-2 voltage stored in the 1-2 sampling capacitor Cs12 is applied to the differential amplifier 65 The second -1 sampling switch S52 and the 2-5 sampling switch S72 are turned off and the second 2-4 sampling switch S62 and the second 2-4 sampling switch S72 are turned off, Since the sampling switch S82 is turned on, the second -2 voltage stored in the second-2 sampling capacitor Cs22 is input to the second input terminal (+) of the differential amplifier 65. [

When the first sampling control signal Csam3 is supplied during the third low potential voltage interval of the low potential voltage interval of the touch driving pulse T, the first-1-1 sampling switch S13 and the 1-5 sampling switch S33 are turned off and the 1-4 sampling switch S23 and the 1-2 sampling switch S43 are turned on so that the 1-3 voltage stored in the 1-3 sampling capacitor Cs13 is output to the differential amplifier 65. [ The second-1 sampling switch S53 and the second-5 sampling switch S73 are turned off and the second-fourth sampling switch S63 and the second-second sampling switch S63 are turned on, The switch S83 is turned on and input to the second input terminal (+) of the second-third voltage differential amplifier 65 stored in the second sampling capacitor Cs23.

When the fourth sampling control signal Csam4 is supplied during the fourth low potential voltage section of the low potential voltage section of the touch driving pulse T, the 1-1 sampling switch S14 and the 1-5 sampling switch S34 are turned off and the 1-4 sampling switch S24 and the 1-2 sampling switch S44 are turned on so that the 1-4 voltage stored in the 1-4 sampling capacitor Cs14 is applied to the differential amplifier 65. [ The second -1 sampling switch S54 and the 2-5 sampling switch S74 are turned off and the second 2-4 sampling switch S64 and the second -2 sampling The switch S84 is turned on and the second-third voltage stored in the second-fourth sampling capacitor Cs24 is input to the second input terminal (+) of the differential amplifier 65. [

The output of the integrator 66 including the differential amplifier 65 becomes Equation 1 when the input signal is a positive voltage.

In Equation (1), Cs is the capacitance of the sampling capacitor, Cint is the capacitance of the integrating capacitor, and? Is the noise component input together with the input signal Vin. In the embodiment of the present invention, since four sampling capacitors are connected in parallel, the total (Cs / Cint +?) Can be expressed by the following equation (2).

In Equation (2),? 1 is a first noise component included in the 1-1 voltage or the 2-1 voltage supplied from the 1-1 or 2-1 sampling capacitor (Cs11, Cs21) -2 or the second noise component included in the second -2 voltage supplied from the second -2 sampling capacitors Cs12 and Cs22 and? 3 is the third noise component included in the 1-3 or 2-3 sampling capacitors A third noise component included in the first-third voltage or the second-third voltage supplied from the first to fourth sampling capacitors Cs13 and Cs23, 4 voltage or the fourth noise component included in the second-fourth voltage.

11 is a waveform diagram for explaining reduction of high frequency noise by the touch sensing apparatus according to the embodiment of the present invention.

11, when high-frequency noise is applied to the sampler 64 by being included in the first and second input signals Vint1 and Vint2, the high-potential voltage section of the touch drive pulse is uniformly divided into four The amount of charge stored in each of the sampling capacitors Cs11, Cs12, Cs13, Cs14, or Cs21, Cs22, Cs23, Cs24 during the period of / 4 is the same and the same voltage level is maintained, . Therefore, when they are accumulated by the integrator 66, the high-frequency noise components are canceled out as shown in Equations (2) and (11). On the other hand, the voltages 1-1 to 1-4 and the voltages 2-1 to 2-4 sampled and stored in the sampler 64 are applied to the first and second integrating capacitors, respectively, as shown in FIG. 10 So that the accumulated voltage value is not changed at all.

Therefore, the high frequency noise included in the input signal can be removed without loss of the voltage level sensed along the touch sensing line, thereby improving the signal-to-noise ratio and increasing the touch sensitivity.

It will be apparent to those skilled in the art that various modifications and variations can be made in the present invention without departing from the spirit or scope of the invention. For example, in the embodiment of the present invention, four sampling capacitors of a sampler are connected in parallel between a first input terminal and a first output terminal, and four parallel-connected sampling capacitors are connected to a second input terminal and a second output terminal. However, this is merely an example, and the number of sampling capacitors can be appropriately adjusted as needed. Therefore, the technical scope of the present invention should not be limited to the contents described in the detailed description of the specification, but should be defined by the claims.

12: Data driving circuit 14: Scan driving circuit
20: display timing controller 30: touch coordinate calculation unit
32: Touch driving line driving circuit 34: Touch sensing line driving circuit
36: Touch sensing timing controller 64: Sampler
65: differential amplifier 66: integrator
68: Analogue Digital Converter (ADC) T1 to Tj: Touch Driven Line
R1 ~ Ri: Touch sensing line
S11, S12, S13, S14, S21, S22, S23, S24, S31, S32, S33, S34, S41, S42, S43, S44, Sb, S51, S52, S53, S54, S61, S64, S71, S72, S73, S74, S81, S82, S83, S84:
Srst1, Srst2: Reset switch
Cs11, Cs12, Cs13, Cs14, Cs21, Cs22, Cs23, Cs24: sampling capacitor
Cint1, Cint2: Integral capacitor

Claims (8)

A touch sensing apparatus including touch driving lines, touch sensing lines intersecting with the touch driving lines,
A touch driving line driving circuit for supplying a plurality of touch driving pulses having a high potential voltage and a low potential voltage to each of the touch driving lines; And
And a touch sensing line driving circuit for dividing and sampling signals received through the touch sensing lines within a period of the touch driving pulse a plurality of times,
The touch sensing line driving circuit includes:
The first and second signals received from the touch sensing lines are sampled and stored in order during each divided period in which the high potential voltage interval of the touch driving pulse is equally divided by 1 / M (M is a natural number equal to or greater than 2) ; And
And an integrator for sequentially integrating the first and second signals sampled by the sampler for each division period in which a low potential voltage interval of the touch driving pulse is equally divided by 1 / M.
The method according to claim 1,
Wherein the sampler comprises:
First and second input terminals and first and second output terminals;
A plurality of first sampling capacitors connected in parallel between the first input terminal and the first output terminal;
A plurality of first sampling switches connected between the first input terminal and the first electrodes of the plurality of first sampling capacitors, respectively;
A plurality of second sampling switches respectively connected between the second electrodes of the plurality of first sampling capacitors and the first output terminal;
A plurality of third sampling switches respectively connected between the first electrodes of the plurality of first sampling capacitors and the node between the plurality of first sampling switches and the ground; And
And a plurality of fourth sampling switches connected between the second electrodes of the plurality of first sampling capacitors, the node between the plurality of second sampling switches, and the ground, respectively.
3. The method of claim 2,
Wherein the sampler further comprises a fifth sampling switch connected between a node between the first input terminal and the plurality of first sampling switches and a ground.
The method of claim 3,
Wherein the sampler comprises:
A plurality of second sampling capacitors connected in parallel between the second input terminal and the second output terminal;
A plurality of sixth sampling switches connected between the second input terminal and the first electrodes of the plurality of second sampling capacitors, respectively;
A plurality of seventh sampling switches connected between the second electrodes of the plurality of second sampling capacitors and the second output terminal, respectively;
A plurality of eighth sampling switches each connected between a node between the first electrodes of the plurality of second sampling capacitors and the plurality of sixth sampling switches, and a ground; And
And a plurality of ninth sampling switches connected between the second electrodes of the plurality of second sampling capacitors, the node between the seventh sampling switches, and the ground, respectively.
5. The method of claim 4,
Wherein the sampler further comprises a tenth sampling switch connected between the node between the second input terminal and the plurality of sixth sampling switches and the ground.
5. The method of claim 4,
The integrator comprising:
A first integrating capacitor for sequentially accumulating the sampling voltages stored in the first sampling capacitors during each divided period in which the low potential voltage section of the touch driving pulse is evenly divided by 1 / M;
A second integration capacitor for sequentially accumulating the sampling voltages stored in the second sampling capacitors during each division period in which the low potential voltage section of the touch driving pulse is equally divided by 1 / M; And
And a differential amplifier connected to the integrating capacitors,
The first integrating capacitor is connected between a first input terminal and a first output terminal of the differential amplifier,
And the second integrating capacitor is connected between the second input terminal and the second output terminal of the differential amplifier.
5. The method of claim 4,
The first sampling switches, the fourth sampling switches, the sixth sampling switches, and the ninth sampling switches are sequentially turned on during each divided period in which the high potential voltage interval of the touch driving pulse is equally divided by 1 / M And,
The second sampling switches, the third sampling switches, the seventh sampling switches, and the eighth sampling switches are sequentially turned on during each divided period in which the low potential voltage section of the touch driving pulse is equally divided by 1 / M The touch sensing device comprising:
6. The method of claim 5,
Wherein the fifth sampling switch and the tenth sampling switch comprise:
Wherein the touch sensing unit is turned on during a low potential voltage period of the touch driving pulse.

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