KR20170046555A - Method and circuit for driving touch sensor and display device using the same - Google Patents

Abstract

The present invention relates to a method and a circuit for driving a touch sensor which can reduce a noise measurement time and current consumption of a touch screen, and a display device using the same. The method for driving a touch sensor comprises the steps of: sensing a touch input by supplying a touch sensor driving signal to the touch sensor or an amplifier during a touch input sensing period; and measuring a current noise received through the touch sensors without the touch sensor driving signal during a noise measurement period.

Description

TECHNICAL FIELD [0001] The present invention relates to a touch sensor driving method and a display device using the touch sensor,

The present invention relates to a touch sensor driving method and circuit for measuring noise received through a finger or a conductor, and a display using the same.

A user interface (UI) enables a user (a user) to communicate with various electric or electronic devices, thereby enabling a user to easily control the device as desired. Representative examples of the 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 functions. User interface technology has been developed to enhance the user's sensibility and ease of operation. The user interface is evolving into touch UI, voice recognition UI, 3D UI and so on.

The touch screen may be implemented by capacitive touch sensors. In addition, the touch screen can be realized by resistive film type, surface ultrasonic type, pressure resistive film type, infrared ray detection type, and the like. The most important factor that determines the performance of such a touch screen is a signal to noise ratio (SNR). When the noise introduced into the touch screen is reduced, the SNR value is increased, thereby widening the operation margin of the touch driving circuit and improving the touch sensing sensitivity.

In order to improve the SNR, it is important to accurately measure the noise introduced into the touch sensor. Since the noise of the touch sensor changes in real time according to the surrounding environment, it must be continuously measured. A method of improving the SNR by avoiding a frequency with a large noise and changing the frequency of the touch sensor driving signal is known. As an example of such a method, the present applicant has proposed a method of changing the frequency of the touch sensor according to the noise level in Korean Patent Laid-Open Publication No. 2001-0057009 (May 06, 2012).

A method of measuring a noise of a touch sensor includes supplying a touch sensor driving signal to a touch sensor, converting the output of the touch sensor at that time into digital data, comparing the data obtained by repeating this method several times, , It is possible to measure the noise affecting the touch sensor. The larger the noise that affects the touch screen, the greater the difference between the minimum and maximum values. This noise measurement method requires a plurality of times to repeatedly apply the touch sensor driving signal to the touch sensor in order to measure the noise, so that the measurement time and current consumption are large.

The present invention provides a touch sensor driving method and circuit for reducing noise measurement time and current consumption of a touch screen, and a display device using the same.

A method of driving a display device according to an exemplary embodiment of the present invention includes driving a display device including a display panel having one or more touch sensors, the method comprising: sensing one or more touches by supplying one or more touch drive signals to the touch sensors; And measuring a first noise of the touch sensors while the touch sensor drive signal is not being supplied to the touch sensors.

The display panel is driven in a display period for displaying images and a touch sensor driving period for touch sensing. The touch driving signal is supplied during the touch input sensing period of the touch sensor driving period. The first noise is measured during a noise measurement period of the touch sensor driving period.

The driving method measures a second noise while the touch sensor driving signal is not supplied to the touch sensors. The driving method compares the first noise with the second noise, and adjusts an operating frequency of a driving circuit that measures noise of the touch sensors based on a result of the comparison.

Wherein the first noise is measured by the driving circuit while the driving circuit is driven at a first frequency and the second noise is measured by the driving circuit while the driving circuit is being driven at a second frequency different from the first frequency .

The driving method further includes shorting the touch sensors selectively while the noise of the touch sensors is measured.

The display device includes a first touch sensor wiring, a second touch sensor wiring, a first input terminal connected to the first touch sensor wiring, and a differential amplifier having a second input terminal.

The driving method further includes selectively connecting a second input terminal of the differential amplifier to the second touch sensor wiring when the touch is sensed and selectively connecting the second input terminal to the reference voltage source when the noise is measured .

The touch sensor driving method of the present invention supplies a touch sensor driving signal to the touch sensor or the amplifier during a touch input sensing period to sense a touch input and receives the touch input signal through the touch sensors without the touch sensor driving signal during a noise measurement period Measure the current noise.

The driving circuit of the display panel according to the embodiment of the present invention is a driving circuit of a display panel having one or more touch sensors, wherein one or more touch driving signals are supplied to the touch sensors to sense a touch, The first noise of the touch sensors is measured while no signal is supplied to the touch sensors.

The display panel is driven during a display period for image display and a touch sensor driving period for touch sensing. The driving circuit senses a touch by supplying the touch driving signal during a touch input sensing period of the touch sensor driving period. The driving circuit measures the first noise during a noise measurement period of the touch sensor driving period.

The driving circuit measures a second noise while the touch sensor driving signal is not supplied to the touch sensors. The first noise is compared with the second noise, and the operating frequency of the driving circuit is adjusted based on the comparison result.

Wherein the first noise is measured by the driving circuit while the driving circuit is driven at a first frequency and the second noise is measured by the driving circuit while the driving circuit is being driven at a second frequency different from the first frequency .

The drive circuit includes circuitry for selectively shorting the touch sensors while the noise of the touch sensors is being measured.

The driving circuit includes an amplifier for amplifying a signal on a sensor wiring connected to the touch sensors, and an integrator for integrating the signal of the amplifier. The driving circuit senses the touch based on the output of the integrator and measures the noise.

Wherein the driving circuit includes a first input terminal connected to the first touch sensor wiring, a differential amplifier having a second input terminal, a second input terminal of the differential amplifier connected to the second touch sensor wiring when the touch is sensed, And a switch for connecting the second input terminal to the reference voltage source when the first input terminal is measured.

The touch sensor driving circuit of the present invention includes an amplifier for amplifying a signal on sensor lines connected to touch sensors, an integrator for integrating an output signal of the amplifier, a multiplexer for connecting the sensor lines to the amplifier, And a touch sensor controller for supplying a touch sensor driving signal to the touch sensor or the amplifier to sense a touch input and measuring a current noise received through the touch sensors during a noise measurement period. The touch sensor driving signal is not generated during the noise measurement period.

The touch-sensing display device of the present invention includes a display panel having one or more touch sensors, a display panel having at least one touch driving signal to the touch sensors to sense a touch, And a touch sensor driver for measuring a first noise of the touch sensors.

The display device of the present invention includes a display driving circuit for writing data of an input image to pixels of the pixel array during the display period, and a touch sensor driving circuit for driving the touch sensors during the touch sensor driving period. The touch sensor driving circuit includes the amplifier, the integrator, the multiplexer, and the touch sensor controller.

The present invention short-circuits two or more touch sensors during a touch noise measurement period and simultaneously measures noise through the touch sensors, thereby shortening a noise measurement time and reducing current consumption. Furthermore, the present invention can more easily measure the noise by shorting a plurality of sensor wirings at the time of noise measurement and increasing the amount of current flowing to the amplifier.

1 is a view showing a display device according to an embodiment of the present invention.
2 is a view showing an electrode pattern of the capacitive-type touch sensors.
3 is a view showing a configuration of a touch sensor driving unit.
4A to 4C are views showing a display period and a touch sensor driving period.
5 is a waveform diagram showing signals applied to signal wirings of a pixel array during a display period and a touch sensor driving period.
6 is a circuit diagram showing the circuit configuration of the sensing unit and the operation of the touch input sensing period.
7 is a waveform diagram showing the operation of the integrator shown in FIG.
8 is a flowchart showing the operation of the charge rejection shown in FIG.
9 is a diagram illustrating the operation of the touch sensor driver 110 in the noise measurement period.
Figs. 10A to 10F are diagrams showing various channel short examples of the sensing unit during the noise measurement period. Fig.
FIG. 11 is a flowchart showing a step-by-step control procedure of a noise measurement method according to an embodiment of the present invention.
12A to 12C are diagrams illustrating noise measured according to a change in the touch driving frequency.
13 and 14 are diagrams showing a normal touch input sensing operation in mutual capacitive type touch sensors.
15 is a diagram illustrating a noise measurement method in mutual capacitance type touch sensors.
16 is a diagram showing a switch connected to the differential amplifier shown in Figs. 13 and 15. Fig.
17 to 19 are views showing a driving apparatus according to an embodiment of the present invention.

The touch sensing display device of the present invention can be applied to a display device having a touch screen, for example, a liquid crystal display (LCD), a field emission display (FED), a plasma display panel Panel, PDP), an organic light emitting diode (OLED) display, and an electrophoresis (EPD) display device. In the following embodiments, a liquid crystal display device will be described as an example of a flat panel display device, but it should be noted that the touch-sensitive display device of the present invention is not limited to a liquid crystal display device.

The touch screen of the present invention may be implemented with capacitance sensors. The capacitive sensor can be divided into a capacitive type touch sensor or a mutual capacitive type touch sensor.

The mutual capacitive type touch sensor includes a mutual capacitance Cm formed between the two electrodes Tx and Rx. The touch sensor driving circuit applies the touch sensor driving signal (or stimulus signal) to the Tx line, receives the charge of the mutual capacitance Cm through the Rx line, and senses the touch input based on the amount of charge change of the mutual capacitance before and after the touch input . The touch sensor driving circuit senses the touch input by using the mutual capacitance Cm when the finger or the conductor approaches the mutual capacitance Cm.

The capacitive type touch sensor includes self capacitance (Cs) formed on each of the sensor electrodes. The touch sensor drive circuit supplies charge to the magnetic capacitance Cs and senses the touch input based on the charge change amount of the magnetic capacitance Cs before and after the touch input. The touch sensor driving circuit senses the touch input by using the capacitance Cs because the capacitance increases when the conductor approaches the capacitance Cs.

The present invention supplies a touch driving signal to touch sensors to sense a touch, and measures a first noise of the touch sensors while a touch sensor driving signal is not supplied to the touch sensors. The present invention is a driving circuit for measuring a second noise while a touch sensor driving signal is not supplied to the touch sensors, comparing the first noise and the second noise, and measuring noise of the touch sensors based on the comparison result Adjust the operating frequency.

The touch sensor driving circuit of the present invention is time-divided into a touch input sensing period for sensing the touch input and a noise measurement period of the touch sensor during the touch sensor driving period. The present invention shortens two or more touch sensors during a noise measurement period and simultaneously measures noise through the touch sensors to shorten the noise measurement time and reduce current consumption.

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. In the following description, a detailed description of known functions and configurations incorporated herein will be omitted when it may make the subject matter of the present invention rather unclear.

1 to 3, the display device of the present invention includes a display panel 100, display drive circuits 102, 104, and 106, and a touch sensor driver 110. The touch screen (TSP) includes capacitive touch sensors.

The display panel 100 includes a pixel array for displaying an input image. The display panel 100 is provided with touch sensors Cs for implementing a touch screen TSP. The touch sensors sense the touch input using mutual capacitance Cm or magnetic capacitance Cs.

The touch sensors may be bonded onto the display panel 100. Alternatively, the touch sensors may be formed on the lower substrate of the display panel 100 together with the pixel array, and may be embedded in the display panel 100 as an in-cell type. Hereinafter, the touch sensors will be described based on an example in which the touch panel is built in the display panel 100, but the present invention is not limited thereto. Figs. 2 and 3 illustrate a capacitive type touch sensor built in the display panel 100. Fig.

The pixel array of the display panel 100 includes the pixels defined by the data lines 101 and the gate lines 103. Each of the pixels is divided into a red subpixel R, a green subpixel G, and a blue subpixel B for color implementation. Each of the pixels may further include a white sub-pixel W. Each of the pixels includes a TFT (Thin Film Transistor) disposed at intersections of the data lines 101 and the gate lines 103, a pixel electrode 11 supplied with a data voltage through the TFT, touch sensors Cs, A storage capacitor Cst connected to the pixel electrode 11 to maintain the voltage of the liquid crystal cell Clc, and the like. Sensor lines 111 connecting the touch sensors Cs to the touch sensor driver 110 are disposed in the pixel array of the display panel 100. [ The liquid crystal molecules of the liquid crystal cell Clc are driven by the electric field generated by the difference between the data voltage applied to the pixel electrode 11 and the common voltage Vcom applied to the electrodes of the touch sensors Cs, And adjusts the transmittance of the pixels according to the data.

A black matrix, a color filter, and the like may be formed on the upper substrate of the display panel 100. The lower substrate of the display panel 100 may be implemented as a COT (Color Filter On TFT) structure. In this case, the color filter is disposed on the lower substrate of the display panel 100. On the upper substrate and the lower substrate of the display panel 100, a polarizing plate is attached and an alignment film for forming a pre-tilt angle of the liquid crystal is formed on the inner surface in contact with the liquid crystal. A column spacer for maintaining a cell gap of the liquid crystal layer is formed between the upper substrate and the lower substrate of the display panel 100.

A backlight unit may be disposed under the rear surface of the display panel 100. The backlight unit is implemented as an edge type or direct type backlight unit to irradiate the display panel 100 with light. The display panel 100 may be realized 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. In a self-luminous display device such as an organic light emitting diode display device, a backlight unit is not required.

When the touch sensors Cs are embedded in the pixel array, one frame period includes at least one display period (Fig. 4, TD) for driving the pixels and at least one touch sensor driving period (TT in Fig. 4). The touch sensors Cs supply the common voltage Vcom to the pixels during the display period TD and sense the touch input during the touch sensor driving period TT. The touch sensor driving period TT is divided into a touch input sensing period (FIG. 4, TT1) for sensing the touch input and a noise measuring period (FIG. 4, TT2) for measuring the noise introduced into the touch sensors.

The display drive circuits 102, 104, and 106 write the data of the input image to the pixels of the display panel. The display drive circuits 102, 104, and 106 include a data driver 102, a gate driver 104, and a timing controller 106.

The data driver 102 converts the digital video data DATA of the input image received from the timing controller 106 into an analog positive / negative gamma compensation voltage to output a data voltage. The data voltage output from the data driver 102 is supplied to the pixels through the data lines 101. [

The gate driver 104 sequentially supplies a gate pulse (or a scan pulse) synchronized with the data voltage to the gate lines 103 to select a line of the display panel 100 to which the data voltage is written. The gate pulse swings between the gate high voltage (VGH) and the gate low voltage (VGL). The gate high voltage VGH is set to a voltage higher than the threshold voltage of the TFT while the gate low voltage VGH is set to a voltage lower than the threshold voltage of the TFT. And supplies the data voltage from the data line 101 to the pixel electrode 11. The pixel electrode 11 is connected to the data line 101,

The timing controller 106 transmits data (RGB) of an input image received from the host system 108 to the data driver 102. The timing controller 106 may generate white data W by calculating a white gain from RGB data for each pixel using a known algorithm.

The timing controller 106 receives the vertical synchronization signal Vsync, the horizontal synchronization signal Hsync, the data enable signal Data Enable and the data enable signal DE received from the host system 108 in synchronization with the data RGB of the input image, And controls the operation timing of the data driver 102, the gate driver 104, and the touch sensor driver 110 using a timing signal such as a clock (MCLK). In FIG. 6, SDC is a data timing signal for controlling the operation timing of the data driver 102. GDC is a gate timing signal for controlling the operation timing of the gate driver 104. [ The timing controller 106 may generate a touch enable signal TEN for defining the display period TD and the touch sensor driving period TT using the input timing signal.

The host system 108 may be implemented in any one of a television system, a set top box, a navigation system, a DVD player, a Blu-ray player, a personal computer (PC), a home theater system, and a phone system. The host system 108 converts the digital video data of the input image into a format suitable for the resolution of the display panel 100, including a system on chip (SoC) with a built-in scaler. The host system 108 transmits the timing signals Vsync, Hsync, DE, and MCLK to the timing controller 106 together with the digital video data RGB of the input image. The host system 108 also executes an application program associated with coordinate information XY of the touch input input from the touch sensor driver 110. [

The touch sensor driving unit 110 converts the amount of charge of the touch sensors Cs into digital data and generates touch raw data (hereinafter referred to as " touch data "). The touch sensor driver 110 executes a known touch sensing algorithm to calculate coordinate values for each of the touch inputs. The touch sensing algorithm judges the touch input by comparing the touch data with a predetermined threshold value, adds the identification code and the coordinate information (XY) to each touch input, and transmits it to the host system 108.

The sensing unit 113 changes a touch sensor driving frequency (or sensing frequency) that varies according to the noise level of the touch sensor. The touch sensor driving unit 110 senses the charge variation of the touch sensor at the touch sensor driving frequency. The touch sensor driver 110 measures the amount of charge flowing through the finger or conductor through the touch sensors Cs during the noise measurement period and compares the noise proportional to the charge amount with the previous noise to measure the noise level.

The touch sensor driving unit 110 includes a multiplexer (MUX) 112, a sensing unit 113, and a touch sensor control unit 114.

The multiplexer 112 reduces the number of channels of the touch sensor driver 110 by connecting the channels of the touch sensor driver 110 to the sensor lines 111 under the control of the touch sensor controller 114. [

The sensing unit 113 amplifies the charge amount of the touch sensor using an amplifier, an integrator, an analog-to-digital converter (ADC), and transmits the amplified charge to the ADC 113. The ADC converts the analog signal received from the integrator to a digital value and outputs the touch data.

The touch sensor control unit 114 executes a touch sensing algorithm to determine a touch input. The touch sensing algorithm compares the touch data received from the ADC 113 with a threshold value during a touch input sensing period, determines a touch input position based on the comparison result, and generates an identification code and coordinate information (XY) .

The touch sensor control unit 114 outputs noise data (hereinafter referred to as " current noise ") received from the ADC 113 during a noise measurement period to noise data (hereinafter referred to as " previous noise ") measured in a previous noise measurement period If the current noise is larger than the previous noise, the touch sensor driving frequency is changed according to a predetermined rule. The touch sensor controller 114 maintains the touch sensor driving frequency at the current frequency if the current noise level is less than the previous noise level. The previous noise is stored and delayed in the memory of the touch sensor control unit 114 so as to be compared with the current noise. The touch sensor control unit 114 may be implemented as a micro control unit (MCU).

4A to 4C are views showing a display period (TD) and a touch sensor driving period (TT). 5 is a waveform diagram showing signals applied to signal wirings of a pixel array during a display period and a touch sensor driving period. In Fig. 5, S1 and S2 are the data line 101, and G1 and G2 are the gate line 103.

4A to 5, the display driving circuits 102, 104, and 106 write data of an input image to pixels of a display panel during a display period (TD). The touch sensor driving unit 110 does not sense the touch input during the display period TD in response to the touch enable signal TEN. The display driving circuits 102, 104, and 106 maintain the data voltage (Vdata) charged in the pixels during the touch sensor driving period (TT).

The data driver 101 can supply the AC signals (LFD in FIG. 5) on the data lines 101 in the same phase as the touch sensor driving signal during the touch sensor driving period TT under the control of the timing controller 106. The voltage of the AC signal LFD may be set to the same voltage as the voltage of the touch sensor driving signal V _MOD . The parasitic capacitance between the touch sensor Cs and the data line 101, which is currently driven due to the AC signal LFD, can be reduced. In another embodiment, the data driver 101 interrupts the current path between its output channels and the data lines 101 during the touch sensor driving period TT under the control of the timing controller 106, It can be maintained in a high impedance state.

The gate driver 103 can supply the gate lines 103 with the AC signal in the same phase as the touch sensor driving signal (FIG. 5, LFD) during the touch sensor driving period TT under the control of the timing controller 106. The voltage of the AC signal LFD may be set to the same voltage or a similar voltage having the same phase with respect to the touch sensor driving signal. The parasitic capacitance between the touch sensor Cs and the gate line 103 which is currently driven due to the AC signal LFD can be reduced.

The AC signal LFD applied to the gate line may be set to a lower voltage level than the touch sensor driving signal because the TFT of the pixels must remain off during the touch sensor driving period TT. For example, if the touch sensor driving signal is a signal having a magnitude of 2V to 8V, the AC signal LFD applied to the gate line may be a signal having a magnitude of -10 to -4V. At this time, the AC signal applied to the gate line is lower in voltage level than the touch sensor driving signal, but it must be set to a signal having the same phase and the same variation size as the touch driving signal, so that the parasitic capacitance can be reduced.

In another embodiment, the gate driver 103 interrupts the current path between its output channels and the gate lines 103 during the touch sensor drive period TT under the control of the timing controller 106, It can be maintained in a high impedance state.

In Insel touch sensor technology, a common electrode connected to pixels of the display panel 100 is divided into touch sensor units and utilized as electrodes of the touch sensors Cs. For example, as described above, in the case of a liquid crystal display device, the in-line touch sensor technology divides the common electrode 12 and divides the divided common electrode patterns into capacitance type touch sensors Cs ). Since these touch sensors are coupled with the pixels, the parasitic capacitance between the touch sensors and the pixels becomes large. Since the touch sensors and the pixels are coupled through the parasitic capacitance, the pixels and the touch sensors are time-division driven as shown in FIG. 4 because they may adversely affect each other electrically. Even in the time division driving method, the touch sensitivity of the touch sensors and the touch recognition accuracy may be deteriorated due to the parasitic capacitance of the display panel 100.

When the AC signal LFD having the same phase as the touch sensor driving signal is supplied to the data lines 101 and gate lines 103 of the display panel 101 during the touch sensor driving period TT, The parasitic capacitance transfer capacitance can be reduced. This is because the voltage difference across the parasitic capacitance can be minimized to minimize the amount of parasitic capacitance charged.

The AC signal LFD and the touch sensor driving signal swing between the high voltage V _REFH and the low voltage V _REFL . The high voltage V _REFH is set to a voltage lower than the gate high voltage VGH and the threshold voltage of the TFT to prevent the pixel TFT from being turned on unwantedly in the touch sensor driving period TT. The touch sensor drive signal may be set differently according to the design specifications of the panel. That is, it can be set as a touch sensor driving signal having an appropriate size in consideration of the voltage required for the panel such as VCC, VDD, common voltage, data driving voltage, gate voltage, and the like.

The touch sensor driving unit 110 may supply the AC signals LFD on the same level as the touch sensor driving signals to the touch sensors other than the touch sensors currently driven during the touch sensor driving period TT. Due to the AC signal LFD, the parasitic capacitance between the electrodes of the currently driven touch sensor can be reduced.

The touch sensor driver 110 supplies the common voltage Vcom of the pixels to the electrodes of the touch sensors Cs through the sensor lines 100 during the display period TD. The touch sensor driving unit 110 senses the touch input during the touch input sensing period TT1 of the touch sensor driving period TT. The multiplexer 112 senses the touch input under the control of the touch sensor controller 114 and selects the touch sensors Cs for each channel. The sensing unit 113 is connected to the touch sensors through the multiplexer 112 and senses the amounts of charges before and after the touch inputs of the touch sensors. Numerals 1 to 10 in FIGS. 3 to 4C show touch sensors Cs connected to the multiplexer 112 on a channel-by-channel basis. For example, in the case where the multiplexer 112 is a 1: 10 multiplexer, the multiplexer 112 outputs the first group of touch sensors to the sensing unit 113 through the first channel CH1 during the touch input sensing period TT1, And sequentially connects the second to tenth channels CH2 to CH10 to the sensing unit 113 to connect the second to tenth groups of touch sensors to the sensing unit 113. [

The touch sensor driving unit 110 measures the noise applied to the touch sensor Cs through the finger or the conductor during the noise measuring period TT2 of the touch sensor driving period TT and changes the touch sensor driving frequency according to the noise level do.

The sensing unit 113 changes the driving frequency of the touch sensor which varies according to the noise level of the touch sensor. The touch sensor driving unit 110 senses the charge variation of the touch sensor at the touch sensor driving frequency. The touch sensor driver 110 measures the amount of charge flowing through the finger or conductor through the touch sensors Cs during the noise measurement period TT2 and compares the noise proportional to the charge amount with the previous noise to determine the noise level .

The touch sensor driving unit 110 generates coordinates of the touch input at a preset touch report rate. The touch sensor driving unit 110 may output the noise measurement value of the touch sensor at a report rate of the same frequency as the touch report rate, but is not limited thereto.

The noise measurement period TT2 may be arranged after the touch input sensing period TT1 as shown in FIG. 4A within the touch sensor driving period TT or may be allocated in front of the touch input sensing period TT1 as shown in FIG. 4B. The noise measurement period TT2 may be divided into the front and back of the touch input sensing period TT1 within the touch sensor driving period TT as shown in FIG. The noise measurement period TT2 may be divided into a plurality of intervals A to B.

The touch sensor driving frequency can be set to the same frequency in each of the A section, the B section, the C section, and the D section. Alternatively, the touch sensor drive frequency may be set at different frequencies in the A, B, C, and D periods. The touch sensor driver 110 measures the noise of the touch sensors during the noise measurement period TT2, compares the current noise with the previous noise, and changes the touch sensor driving frequency to another frequency when the current noise is high. The touch sensor driving unit 110 may change the touch sensor driving frequency within the noise measurement period TT2.

6 to 8 illustrate the operation of the touch sensor driver 110 in the touch input sensing period TT1.

6 is a circuit diagram showing the circuit configuration of the sensing unit 113 and the operation of the touch input sensing period. 6 shows an operation in which the sensing unit 113 senses a touch input through the touch sensors Cs connected to the first channel CH1. At this time, the AC signals LFD having the same phase as the touch sensor driving signal are supplied to the sensor lines 111 connected to the channels CH2 to CH10 other than the first channel CH1. 7 is a waveform diagram showing the operation of the integrator shown in FIG. 8 is a flowchart showing the operation of the charge rejection shown in FIG. The circuit configuration of the sensing unit 113 is not limited to Fig. In FIG. 6, TSP means a touch screen composed of touch sensors. The touch IC refers to an integrated circuit (IC) on which the touch sensor driver 110 is integrated.

6 to 8, the analog circuit of the sensing unit 110 includes a preamplifier (PREAMP) and an integrator (INT). An ADC (not shown) is connected to the output terminal of the integrator INT.

The preamplifier amplifies the signal on the sensor lines (111) connected to the touch sensors. The preamplifier (PREAMP) can amplify the amount of charge in the rising period of the touch sensor driving signal (V _MOD ). The touch sensor control unit 114 supplies the touch sensor driving signal V _MOD to the inverting input terminal (-) of the preamplifier PREAMP in the touch input sensing period TT1, And supplies the reference voltage VREFL to the inverting input terminal (-) of the preamplifier PREAMP.

A charge rejection (ACR) may be connected to the input terminal of the preamplifier PREAMP. Charge canceling (ACR) reduces the variation of touch sensor signals appropriately. This charge rejection (ACR) may be omitted.

The touch sensor driving signal V _MOD is applied to the reference voltage terminal of the preamplifier PREAMP, that is, the inverting input terminal (+), as shown in FIG. 6 in the case of the capacitance type touch sensor Cs. In the case of the mutual capacitance type touch sensor Cm as shown in FIGS. 13 to 15, the touch sensor driving signal V _MOD is directly applied to the Tx line.

The preamplifier PREAMP includes a first amplifier OPP, a feedback capacitor C _FBP , and a reset switch SW _RP . The first amplifier OPP may be a single-ended amplifier as shown in FIG. A feedback capacitor C _FBP and a reset switch SW _RP are connected in parallel between the inverting input terminal (-) and the output terminal of the first amplifier OPP. The touch sensor driving signal V _MOD is supplied as the reference voltage V _REFP to the non-inverting input terminal (+) of the first amplifier OPP. The touch sensor drive signal (V _MOD ) swings between V _REFH and V _REFL . Since charge is supplied to the touch sensor Cs due to the touch sensor driving signal V _MOD , the amount of charge of the touch sensor before and after the touch input can be known. The output voltage (V _OUTP ) of the preamplifier (PREAMP) when the charge rejection does not operate is expressed by Equation (1) below.

Here, C _FIN is the capacitance between the finger or conductor and the touch sensor.

The integrator INT amplifies the difference between the output voltage V _OUTP of the preamplifier _PRE and the reference voltage V _REFI of the integrator at a ratio of its gain α = Cs / C _FBI, And accumulates and integrates the sampled voltage in the capacitor CFBI. Here, Cs is the capacitance of the sampling capacitor, and CFBI is the feedback capacitor capacitance of the integrator INT.

The integrator INT shown in FIG. 6 accumulates the output voltage of the electronic amplifier by DI (Delta Integration) and DS (Double sampling). DI is a technique for integrating only the difference between touch data and non-touch data. The DS samples the output voltage of the integrator INT during a rising period and a falling period of a driving signal applied to the touch sensor. The integrator (INT) of the present invention can implement a DS using a single-ended amplifier so that the circuit area is not increased due to the DS.

The integrator INT includes a first sampling circuit SCC1, a second sampling circuit SCC2, an integral capacitor CFBI, a second amplifier OPI, and the like.

The first and second sampling circuits SCC1 and SCC2 are connected to the inverting input terminal (-) of the second amplifier OPI. A reset switch SW _RI and a feedback capacitor C _FBI are connected between the inverting input terminal (-) and the output terminal of the second amplifier OPI. The reference voltage V _REFI is supplied to the non-inverting input terminal (+) of the second amplifier OPI.

The reference voltages V _REFIH and V _{REFIL of} the first and second sampling circuits SCC1 and SCC2 are set to the same voltage as the output voltage V _OUTP of the preamplifier PREAMP at the non- Respectively. First and second sampling circuit, the reference voltage (V _REFI) of (SCC1, SCC2) is equal to the reference voltage (V _REFI) of the second amplifier (OPI). Therefore, the integrator INT integrates only the difference between the voltage at the touch input and the voltage at the non-touch state. As a result, the integration frequency of the integrator INT can be increased without increasing the capacity of the integral capacitor C _FBI .

The first sampling circuit SCC1 samples V _OUTP in the rising period of the touch sensor driving signal V _MOD . A first sampling circuit (SCC1) is the 1a switch (SW _11), the 1b switch (SW _12), first 2a switch (SW _21), the 2b switch (SW _22), and a first sampling capacitor (C _S1) of . The first and the first switches SW ₁₁ and SW ₁₂ are turned on / off in response to the first switch control signal SW 1 shown in FIG. 2a and 2b the first switch (SW _21, SW ₂₂₎ to the second switch in response to a control signal (SW2) on / off. The switch control signals SW _RP , SW _RI , SW 1, SW 2, SW 3 and SW 4 shown in FIG. 7 may be generated in the touch sensor control unit 114.

The first and the first switches SW ₁₁ and SW ₁₂ are turned on simultaneously before the rising period of the touch sensor driving signal V _MOD to supply V _OUTP to the first sampling capacitor C _S1 And charges the charge amount of the touch sensor Cs in the rising period. The off (turn-off) - first 2a and second 2b switch (SW _21, SW ₂₂₎ is a touch sensor drive signal first 1a and second 1b switches in the rising period of the _{(V MOD) (SW 11,} SW 12) is turned Then turned on. The 2a and 2b switches SW ₂₁ and SW _{22 supply} V _OUTP to the feedback capacitor C _FBI of the second amplifier OPI within the rising period of the touch sensor driving signal V _MOD .

The voltage sampled during the rising period of the touch sensor drive signal (V _MOD ) is V _OUTP - V _REFIH . If V _OUTP is the output voltage V1 of the preamplifier (PREAMP) and V _REFIH is set to V1 in the non-touch state, V _OUTP -V _REFIH = V1-V1 = 0. When a touch input occurs, V _OUTP increases V _REFIH .

The second sampling circuit SCC2 samples V _OUTP in the polling interval of the touch sensor driving signal (V _MOD ). The second sampling circuit SCC2 includes a third switch SW31, a third switch SW32, a fourth switch SW41, a fourth switch SW42 and a second sampling capacitor CS2. 3a and 3b the first switch (SW _31, SW ₃₂₎ is on / off in response to the third switch control signal (SW3) shown in Fig. 4a and 4b the first switch (SW _41, SW ₄₂₎ is the fourth on / off in response to a switch control signal (SW4). The third and the third switches SW ₃₁ and SW ₃₂ are turned on before the rising period of the touch sensor driving signal V _MOD to initialize the voltage of the second sampling capacitor C _S2 to V _REFIL -V _REFI . The fourth and fourth switches SW ₄₁ and SW ₄₂ are turned on prior to the polling interval of the touch sensor driving signal V _{MOD to} switch V _OUTP to the feedback capacitor C _FBI through the second sampling capacitor C _S2 , . The voltage sampled during the polling interval of the touch sensor drive signal (V _MOD ) is V _REFIL - V _OUTP . When V _OUTP is non-touch, VREFI2-VOUTP = V2-V2 = 0 if the output voltage is V2 of the preamplifier (PREAMP). If a touch input occurs in the polling interval of the touch sensor drive signal (V _MOD ), V _OUTP is lower than V _REFIL because it is a negative voltage.

6, the integrator INT can integrate only the difference between the touch voltage and the non-touch voltage in the integrator INT, and the first sampling circuit SCC1 and the second sampling circuit SCC2 Double sampling can be implemented with a second amplifier (OPI) by sampling the input voltage alternately. The integrator (INT) of the present invention is not limited to the circuit as shown in Fig. For example, the integrator of the present invention can be implemented with a simpler circuit that accumulates the input voltage only in the rising period and the polling period of the touch sensor driving signal (V _MOD ).

If the capacitance value of the touch sensor is large as in the case of the large-screen display panel, the output voltage (V _OUTP ) of the preamplifier (PREAMP) becomes large so that V _OUTP may saturate out of the allowable range defined by the specification of the touch IC have. In this case, it is not easy to determine the touch input because V _OUTP is almost the same or almost similar in the touch input and non-touch state. The charge rejection (ACR) can be applied to adjust the charge amount of the touch sensor appropriately.

The charge rejection (ACR) includes one or more capacitors (C _C , C _F ), first and second switches (SW _A , SW _B ).

One electrode of the capacitor (C _C, C _F) is the inverting input terminal of the first amplifier (OPP) via a first switch (SW _A) - is connected to the (). One electrode of the capacitors C _C and C _F is connected to the non-inverting input terminal (+) of the first amplifier OPP via the second switch SW _B. The charge erasing pulse signals V _{CR_C} and V _{CR_F} are supplied to the other electrodes of the capacitors C _C and C _F during the touch input sensing period TT1. 8, V _CR represents V _{CR_C} and V _{CR_F} shown in FIG.

The first and second switches SW _A and SW _B are turned on alternately under the control of the touch sensor controller 114 as shown in FIG. In other words, the first and second switches SW _A and SW _B are turned on when one of the switches is turned on in response to the switch control signals of opposite phases to each other, -off).

The first switch SW _A is turned on and the second switch SW _B is turned off at a timing earlier than the falling edge of the charge erasing pulse signals V _{CR_C} and V _{CR_F} . A first switch (SW _A) on (on) is polled for the charge erase pulse signal (V _{CR_C,} V _{CR_F)} in state, the more such a polling frequency increases the output voltage (Vout) accumulated count of the adjustment value of is increased .

The output voltage (V _OUTP ) of the preamplifier (PREAMP) when the charge rejection (ACR) operates is shown in Equation (2) below. As can be seen from Equation (2), the charge rejection (ACR) can be achieved by using an amplifier (not shown) within a range that satisfies the input voltage range input to the ADC without increasing the size of the touch IC, PREAMP) and the integrator (INT).

Here, CCR is the capacitance of the capacitors C _C and C _F. C _S is the capacitance of the touch sensor C _S. n is the number of charge erasing pulse signals (VCR_C, VCR_F).

The touch sensor driving frequency is the operating frequency of the sensing unit 113. More specifically, the touch sensor driving frequency means the operating frequency of the switch elements SWRP and SWRI SW1 to SW4 as the driving frequency of the integrator INT and the preamplifier PREAMP. The switch elements SWRP and SWRI SW1 to SW4 are turned on / off in synchronization with each other at the same frequency. Hereinafter, the touch sensor driving frequency described in the noise measuring method of the touch sensor means the operating frequency of the switch elements SWRP and SWRI SW1 to SW4.

9 is a view showing the operation of the touch sensor driver 110 in the noise measurement period TT2.

Referring to FIG. 9, in the case of a touch sensor of a magnetic capacitance type, the present invention excludes the charge of the touch sensor during the noise measurement period TT2 and, in order to measure the noise only by the amount of charge flowing through the finger or the conductor, The driving signal V _MOD is not generated. During the noise measurement period TT2, the sensing unit 113 operates at the currently set touch sensor driving frequency to sense the noise introduced through the touch sensor. A charge can flow to the sensing unit 113 through the touch sensor through the user's finger due to a fluorescent lamp or an electronic device, and the charge flowing from the external environment acts as noise to the touch sensor signal.

The sensing unit 113 connects the two or more channels CH1 to CH10 to one preamplifier PREAMP and outputs the touch sensors Cs connected to the two or more sensor wirings 111 during the noise measurement period TT2, To simultaneously measure the noise introduced from the external environment. To this end, the multiplexer 112 short-circuits two or more channels CH1 to CH10 and connects them to the inverting input terminal (-) of the preamplifier PREAMP. Therefore, during the noise measurement period TT2, only the electric charge flowing into the touch sensors through the finger or the conductor is input to the preamplifier PREAMP.

The sensing unit 113 receives the low voltage VREFL at the non-inverting input terminal (+) of the preamplifier PREAMP to amplify only the amount of charge flowing through the finger or conductor during the noise measurement period TT2. The low voltage VREFL may be set to a DC voltage higher than 0 V and lower than the power supply voltage VDD. VDD is the supply voltage between 3.3V and 12V. The present invention is characterized in that the reference voltage input to the capacitors C _C and C _F of the preamplifier PREAMP and the charge rejection circuit ACR is fixed to 0 V during the noise measurement period TT2, . The integrator INT operates in the same manner in the touch input sensing period TT1 and the noise measuring period TT2 to accumulate and amplify the noise voltage amplified by the preamplifier PREAMP to the ADC.

The sensing unit 113 converts the analog voltage output from the integrator INT during the noise measurement period TT2 into digital data via the ADC. The touch sensor control unit 114 receives the digital data as the current noise during the noise measurement period TT2, compares the digital data with the previous noise stored in the memory, and changes the touch sensor driving frequency when the current noise is higher than the previous noise. On the other hand, the touch sensor control unit 114 receives the noise measurement period TT2 digital data as the current noise, compares it with the previous noise stored in the memory, and maintains the current touch sensor driving frequency when the current noise is less than the previous noise .

The output voltage (V _OUTP ) of the preamplifier (PREAMP) when the charge rejection (ACR) does not operate is expressed by Equation (3) below.

Where C _FIN is the capacitance between the finger or conductor and the touch sensor. ΔV _noise is the input voltage of the preamplifier (PREAMP) caused by the charge flowing through the finger or conductor.

The present invention can shorten the noise measurement time by simultaneously measuring the noise introduced into the touch sensors through the finger or the conductor in a state where a plurality of sensor wires are short-circuited during the noise measurement period TT2 by the multiplexer 112. [ In addition, the present invention shortens a plurality of sensor wirings to increase the amount of current flowing to the preamplifier (PREAMP), thereby increasing the noise voltage, thereby enabling noise measurement even if the noise is small.

Figs. 10A to 10F are diagrams showing various channel short examples of the sensing unit during the noise measurement period. Fig.

10A to 10F, the touch sensor driver 110 of the present invention can short-circuit the sensor wires in various forms using the multiplexer 112 to connect a plurality of sensor wires to one channel in the sensing unit 113. [ The touch sensor driving unit 110 can short-circuit all the sensor wirings and simultaneously measure the noise introduced through all the touch sensors Cs.

FIG. 11 is a flowchart showing a step-by-step control procedure of a noise measurement method according to an embodiment of the present invention. 12A to 12C are diagrams illustrating noise measured according to a change in the touch driving frequency.

Referring to FIGS. 11 to 12C, the touch sensor controller 114 senses a charge amount of the touch sensors at the touch sensor driving frequency during the touch input sensing period TT1 of the touch sensor driving period TT. The touch sensor control unit 114 senses the amount of charge of the touch sensors during the noise measurement period TT2 at the touch sensor driving frequency maintained during the touch input sensing period TT1 to measure noise (S1 and S2).

The present invention can be carried out every frame period, and noise measurement of the touch sensor can be performed once at a specific time period, for example, every several seconds. The noise can be measured immediately after the power of the display device is turned on by the user and the noise can be measured when the power is turned on again. When the power off command of the display device is received from the user, the power off timing may be delayed, the noise may be measured to change the touch sensor driving frequency, and then the power may be turned off. In addition, the user can measure the noise when the user desires through the user interface, and the noise can be temporarily measured in the standby mode. If noise is measured every frame period, it can respond quickly to changes in the noise environment. Measuring the noise once at a specific time period or measuring the noise at power on / off can reduce the power consumption required for noise measurement.

Various methods for changing the frequency for noise detection are possible within the operating range of the touch sensor driver 110. [ The noise can be measured by repeating the process of sequentially raising and lowering the driving frequency of the touch sensor. For example, you can change the touch sensor drive frequency during noise measurement in the same way as 80Hz -> 90Hz -> 100Hz -> 110Hz -> 100Hz -> 90Hz -> 80Hz. As another example, the touch sensor driving frequency can be changed randomly at the time of noise measurement. For example, you can change the frequency in the same way as 80Hz -> 110Hz -> 100Hz -> 90Hz. If the current noise is larger than the previous noise (S3 and S4), the touch sensor controller 114 changes the current touch sensor driving frequency to a preset frequency changing method and repeats steps S1 to S4. On the other hand, if the current noise is less than the previous noise, the touch sensor control unit 114 senses the touch input at the current frequency (S5).

The noise level of the external environment flowing to the touch sensor may vary according to the frequency of the noise and the driving frequency of the touch sensor, as shown in FIGS. 12A to 12C. For example, when the touch sensor driving frequency is SW _{RP (1)} , as shown in Figs. 12A to 12B, the electromotive force Q introduced from the outer circumferential environment becomes larger than the SW _{RP (2)} and SW _{RP (3)} . In this case, the present invention adjusts the touch sensor driving frequency to SW _{RP (2)} or SW _{RP (3)} to drive the touch sensors.

Although the present invention has been described with reference to the magneto-capacitance type touch sensors Cs in the above-described embodiment, it is not limited thereto. Figs. 13 to 15 show embodiments of capacitive touch sensors. Fig.

13 and 14 are diagrams showing a normal touch input sensing operation in mutual capacitive type touch sensors.

13 and 14, the sensor lines 111 include Tx lines Tx1 to Tx4 and Rx lines Rx1 to Rx4 orthogonal to each other with an insulating layer interposed therebetween. The mutual capacitance type touch sensor Cm is formed between the Tx lines Tx1 to Tx4 and the Rx lines Rx1 to Rx4.

The touch sensor driving unit 110 supplies a touch sensor driving signal to the Tx lines Tx1 to Tx4 and outputs the touch sensor driving signals to the touch sensors Cm received through the Rx lines Rx1 to Rx4 in synchronization with the touch sensor driving signal Receives the charge amount, amplifies and integrates the charge amount. When a touch input occurs through a finger or a conductor, the amount of charge of the touch sensor is reduced. Therefore, the mutual capacitive type touch sensors can determine the touch input based on the differences in the amount of charge before and after the touch input.

A differential amplifier (OP) may be connected to the Rx lines Rx1 to Rx4. The sensing unit 113 may receive the amplified signal through a differential amplifier OP connected to two neighboring Rx lines. The output terminal of the differential amplifier OP is connected to the inverting input terminal (-) via the capacitor C. Each of the differential amplifiers OP outputs a difference between the i-th (i is a positive integer) touch sensor signal input to the inverting input terminal (-) and the i + 1 touch sensor signal input to the non-inverting input terminal And outputs an i-th sensor signal. The differential amplifiers OP can improve the SNR by amplifying the difference between the signals received through the neighboring Rx lines as shown in FIG. 14 to make the signal components larger than noise.

The differential amplifiers OP can reduce the noise received through the touch sensors Cm during the touch input sensing period TT1, but make the noise measurement difficult.

The present invention supplies a predetermined reference voltage V _REF to the non-inverting terminal of the differential amplifier OP as shown in Figs. 15 and 16 in order to prevent the noise from becoming too small at the time of noise measurement. The switch SW ₅₀ may be connected to the non-inverting input terminal (+) of the differential amplifier OP as shown in FIG. Switch (SW ₅₀₎ is a touch input sensing period (TT1) for connecting the Rx line to the non-inverting input terminal (+) of the differential amplifier (OP), and a DC reference voltage (VREF) to the noise measurement period (TT2), a differential amplifier Inverting input terminal (+) of the operational amplifier OP. The reference voltage VREF may be set to a voltage between 3.3V and 12V.

The touch sensor driving signal is not applied to the Tx lines Tx1 to Tx4 in order to exclude the amount of charge charged to the touch sensor at the time of noise measurement and to measure only the noise flowing into the touch sensors through the finger or the conductor.

The driving circuit of the display device including the display driving circuits 102, 104, and 106 and the touch sensor driving unit 110 may be implemented in various forms. 17 to 19 show examples in which the driving circuit is applied to a mobile device.

Referring to Fig. 17, the drive circuit includes a drive IC (DIC) and a touch IC (TIC).

The drive IC DIC includes a touch sensor channel unit 210, a Vcom buffer 211, a switch array 212, a timing control signal generation unit 213, a multiplexer 214, and a DTX compensation unit 215, .

The touch sensor channel unit 210 is connected to the electrodes of the touch sensors Cs and Cm through the sensor lines 111 and is connected to the Vcom buffer 211 and the multiplexer 214 through the switch array 212 . The multiplexer 214 couples the sensor line 111 to the touch IC (TIC). In the case of the 1: 3 multiplexer, the multiplexer 214 reduces the number of channels of the touch IC (TIC) by time-sharing one channel of the touch IC (TIC) to the three sensor lines 111. The multiplexer 214 selects the sensing lines to be connected to the channel of the touch IC (TIC) in response to the MUX control signals MUX C1 to C3. The multiplexer 214 is connected to the channels of the touch IC (TIC) through the touch lines.

The Vcom buffer 211 outputs the common voltage Vcom of the pixel. The switch array 212 supplies the common voltage Vcom from the Vcom buffer 211 to the touch sensor channel unit 210 under the control of the timing control signal generator 213. [ The switch array 212 connects the sensor line 111 to the touch IC (TIC) during the touch sensor driving period TT under the control of the timing control signal generator 213.

The timing control signal generating unit 213 generates timing control signals for controlling the operation timings of the display driving circuits 102, 104, and 106 and the touch IC (TIC). The display drive circuits 102, 104, and 106 write the data of the input image to the pixels as described above. The data driver 102 generates a data voltage of the input image and supplies the data voltage to the data lines 101 of the display panel 100. The data driver 102 may be integrated in the drive IC (DIC). The gate driver 104 sequentially supplies a gate pulse (or a scan pulse) synchronized with the data voltage to the gate lines 103 of the display panel 100. [ The gate driver 104 may be formed directly on the substrate on which the pixel array is disposed.

The timing control signal generator 213 is substantially the same as the timing control signal generator in the timing controller 106 shown in Fig. The timing control signal generating section 213 drives the display driving circuits 102, 104 and 106 during the display period TD and drives the touch IC TIC during the touch sensor driving period TT.

The timing control signal generating unit 213 generates a touch enable signal TEN defining the display period TD and the touch sensor driving period TT and outputs the touch enable signal TEN to the display driving circuits 102, Synchronize the touch IC (TIC). The display driving circuits 102, 104, and 106 write data to the pixels during the first level period of the touch enable signal TEN. The touch IC drives the touch sensors Cs and Cm in response to the second level of the touch enable signal TEN to sense the touch input. 4A to 4C, the first level of the touch enable signal TEN may be a low level, the second level may be a high level, and vice versa have.

The noise may be increased in the touch sensor signal according to the change of the input image data. The DTX compensating unit 215 analyzes the input image data and removes noise of the touch data that varies according to the gradation change of the input image. The touch data output from the DTX compensation unit 215 is transmitted to the touch IC (TIC). DTX stands for Display and Touch crosstalk. The DTX compensation unit 215 may use the DTX compensation algorithm disclosed in Korean Patent Application No. 10-2014-0079689 filed by the present applicant.

When the parasitic capacitance connected to the touch sensor is minimized by applying the AC signal LFD on the same level as the touch sensor driving signal to the data lines 101 and the gate lines 103 during the touch sensor driving period TT, can do. Therefore, when this technique is applied, since the parasitic capacitance between the pixels and the touch sensors can be minimized, the noise of the touch sensor does not change sensitively according to the data change of the input image. In this case, the DTX compensation unit 215 is not necessary and can be omitted. In Fig. 17, DTX DATA is the output data of the DTX compensating unit 15. Fig.

The touch IC TIC drives the multiplexer 214 during the touch interval in response to the touch enable signal TEN from the timing control signal generator 213 to generate a touch signal through the multiplexer 214 and the sensor lines 111 And receives charges of the sensors Cs and Cm.

The touch IC (TIC) detects the amount of charge before and after the touch input from the received signal of the touch sensor, compares the amount of charge with a predetermined threshold value, and determines the position of the touch sensor having the amount of charge equal to or higher than the threshold value as the touch input area. The touch IC (TIC) calculates coordinates for each of the touch inputs and transmits the touch data including the touch input coordinate information to the external host system 108. The touch IC (TIC) includes an amplifier for amplifying the charge of the touch sensor, an integrator for accumulating the charge received from the touch sensor, an ADC for converting the voltage of the integrator into digital data, and an arithmetic logic section. The arithmetic logic unit compares the touch data output from the ADC with a threshold value, and executes a touch sensing algorithm for determining a touch input and calculating coordinates according to the comparison result.

The drive IC (DIC) and the touch IC (TIC) can send and receive signals through the SPI (Serial Peripheral Interface).

Referring to FIG. 18, the drive circuit includes a drive IC (DIC) and an MCU (Micro Controller Unit).

The drive IC DIC includes a touch sensor channel unit 210, a Vcom buffer 211, a switch array 212, a first timing control signal generation unit 213, a multiplexer 214, a DTX compensation unit 215, A second timing control signal generator 217 and a memory 218. [ This embodiment differs from the embodiment of FIG. 17 in that the sensing unit 216 and the second timing control generator 217 are integrated in the drive IC (DIC). The first timing control generator 213 is substantially the same as that of Fig. Therefore, the first timing control generator 213 generates timing control signals for controlling the operation timings of the display driving circuits 102, 104, and 106 and the touch IC (TIC).

The sensing unit 216 includes an amplifier for amplifying the charge of the touch sensor, an integrator for accumulating the charge received from the touch sensor, and an ADC for converting the voltage of the integrator to digital data. The touch data output from the ADC is transmitted to the MCU. The second timing control generator 217 generates a timing control signal and clock for controlling the operation timing of the multiplexer 214, the sensing unit 216, and the like. The DTX compensation section 215 in the drive IC (DIC) may be omitted. The memory 218 temporarily stores the touch data under the control of the second timing control generator 217.

The drive IC (DIC) and the MCU can send and receive signals through the SPI (Serial Peripheral Interface). The MCU compares the touch data with a threshold value and executes a touch recognition algorithm to determine the touch input according to the comparison result and to calculate coordinates.

Referring to Fig. 19, the drive circuit includes a drive IC (DIC) and a memory (Memory, MEM).

The drive IC DIC includes a touch sensor channel unit 210, a Vcom buffer 211, a switch array 212, a first timing control signal generation unit 213, a multiplexer 214, a DTX compensation unit 215, A second timing control signal generation unit 217, a memory 218, and an MCU 219. The second timing control signal generation unit 217, This embodiment differs from the above-described embodiment of Fig. 18 in that the MCU 219 is integrated in the drive IC (DIC). The MCU 219 compares the touch data with a threshold value, and executes a touch sensing algorithm for determining a touch input and calculating coordinates according to the comparison result.

The memory MEM stores a register setting value related to timing information necessary for operations of the display driving circuits 102, 104, and 108 and the sensing unit 16. [ When the power of the register set value display device is turned on from the memory MEM, the data is loaded into the first timing control signal generator 216 and the second timing control signal generator 217. The first timing control signal generation unit 216 and the second timing control signal generation unit 217 control the display driving circuits 102, 104 and 106 and the sensing unit 216 based on the register setting values read from the memory Lt; / RTI > It is possible to cope with the model change by changing the register setting value of the memory MEM without structural modification of the driving apparatus.

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. 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.

100: display panel 102: data driver
104: Gate driver 106: Timing controller
108: host system 110: touch sensor driver
112: Multiplexer 113:
114: Touch sensor control unit

Claims (38)

A method of driving a display device including a display panel having one or more touch sensors,
Supplying at least one touch driving signal to the touch sensors to sense the touch; And
And measuring a first noise of the touch sensors while the touch sensor driving signal is not supplied to the touch sensors. The method according to claim 1,
The display panel is driven in a display period for video display and a touch sensor driving period for touch sensing,
The touch driving signal is supplied during a touch input sensing period of the touch sensor driving period,
Wherein the first noise is measured during a noise measurement period of the touch sensor driving period. The method according to claim 1,
Measuring a second noise while the touch sensor driving signal is not supplied to the touch sensors;
Comparing the first noise and the second noise; And
And adjusting an operation frequency of a driving circuit for measuring noise of the touch sensors based on a result of the comparison. The method of claim 3,
Wherein the first noise is measured by the driving circuit while the driving circuit is driven at a first frequency and the second noise is measured by the driving circuit while the driving circuit is being driven at a second frequency different from the first frequency And driving the display device. The method according to claim 1,
And selectively shorting the touch sensors while the noise of the touch sensors is being measured. The method according to claim 1,
The display device includes a first input terminal connected to the first touch sensor wiring, a second touch sensor wiring, a first touch sensor wiring, and a differential amplifier having a second input terminal,
Selectively connecting a second input terminal of the differential amplifier to a second touch sensor wiring when the touch is sensed; And
And selectively connecting the second input terminal to a reference voltage source when the noise is measured. A touch sensor driving method using an amplifier for amplifying a signal on sensor lines connected to touch sensors, an integrator for integrating an output signal of the amplifier, and a multiplexer for connecting the sensor lines to the amplifier,
Sensing a touch input by supplying a touch sensor driving signal to the touch sensor or the amplifier during a touch input sensing period; And
And measuring a current noise received through the touch sensors without the touch sensor driving signal during a noise measurement period. 8. The method of claim 7,
Comparing the current noise with a previous noise measured in a previous noise measurement interval and changing the driving frequency of the amplifier and the integrator if the current noise is greater than the previous noise; And
And maintaining the driving frequency of the amplifier and the integrator at the current frequency if the current noise is less than the previous noise. 9. The method of claim 8,
Sequentially connecting the sensor lines to the amplifier during the touch input sensing period; And
And simultaneously connecting two or more sensor lines to the amplifier during the noise measurement period. A driving circuit for a display panel comprising at least one touch sensor,
Wherein at least one touch driving signal is supplied to the touch sensors to sense a touch and the first noise of the touch sensors is measured while the touch sensor driving signal is not supplied to the touch sensors. 11. The method of claim 10,
The display panel is driven in a display period for video display and a touch sensor driving period for touch sensing,
Wherein the driving circuit supplies the touch driving signal during a touch input sensing period of the touch sensor driving period to sense a touch,
Wherein the driving circuit measures the first noise during a noise measurement period of the touch sensor driving period. 11. The method of claim 10,
The driving circuit measures a second noise while the touch sensor driving signal is not supplied to the touch sensors,
And compares the first noise with the second noise, and adjusts the operating frequency of the driving circuit based on the comparison result. 13. The method of claim 12,
Wherein the first noise is measured by the driving circuit while the driving circuit is driven at a first frequency and the second noise is measured by the driving circuit while the driving circuit is being driven at a second frequency different from the first frequency And a driving circuit for driving the display panel. 11. The method of claim 10,
Wherein the driving circuit includes a circuit for selectively shorting the touch sensors while the noise of the touch sensors is measured. 11. The method of claim 10,
The drive circuit
An amplifier for amplifying a signal on a sensor wiring connected to the touch sensors; And
And an integrator for integrating the signal of the amplifier,
Wherein the driving circuit senses a touch based on an output of the integrator and measures noise. 11. The method of claim 10,
A differential amplifier having a first input terminal connected to the first touch sensor wiring and a second input terminal; And
And a switch for connecting the second input terminal of the differential amplifier to the second touch sensor wiring when the touch is sensed and for connecting the second input terminal to the reference voltage source when the noise is measured. An amplifier for amplifying a signal on sensor lines connected to the touch sensors;
An integrator for integrating an output signal of the amplifier;
A multiplexer coupling the sensor lines to the amplifier; And
And a touch sensor controller for supplying a touch sensor driving signal to the touch sensor or the amplifier to sense a touch input during a touch input sensing period and measuring a current noise received through the touch sensors during a noise measurement period,
Wherein the touch sensor driving signal is not generated during the noise measurement period. 18. The method of claim 17,
The touch sensor driver includes:
Comparing the current noise with a previous noise measured in a previous noise measurement period and changing the driving frequency of the amplifier and the integrator if the current noise is greater than the previous noise,
And maintains the driving frequency of the amplifier and the integrator at a current frequency when the current noise is less than the previous noise. 18. The method of claim 17,
The touch sensor control unit,
The sensor lines are sequentially connected to the amplifier during the touch input sensing period,
And simultaneously connects two or more sensor lines to the amplifier during the noise measurement period. 18. The method of claim 17,
The amplifier
An inverting input terminal connected to the sensor lines through the multiplexer;
A non-inverting input terminal to which the touch driving signal is applied during the touch input sensing period and to which a DC reference voltage is supplied during the noise measuring period;
An output terminal connected to an input terminal of the integrator; And
And a feedback capacitor and a reset switch connected in parallel between the inverting input terminal and the output terminal. 21. The method of claim 20,
Further comprising charge rejection coupled to an inverting input terminal of the amplifier,
The charge rejection may comprise:
A first switch connected to an inverting input terminal of the amplifier;
A second switch coupled to the non-inverting input terminal of the amplifier; And
And at least one capacitor connected to the first switch and the second switch,
During the touch input sensing period, the first and second switches are alternately turned on
Wherein a pulse is supplied to the capacitor during the touch input sensing period and 0V is applied to the capacitor during the noise measurement period. 18. The method of claim 17,
The touch sensor
A touch sensor driving circuit including a touch sensor of a magneto-capacitance type or mutual capacitance type. 18. The method of claim 17,
A differential amplifier receiving a signal of the neighboring sensing lines and performing differential amplification of the signals of the neighboring sensor lines; And
And a switch for connecting a sensor line to a non-inverting input terminal of the differential amplifier during the touch input sensing period and supplying a DC reference voltage to a non-inverting input terminal of the differential amplifier during the noise measurement period, . A display panel having one or more touch sensors;
And a touch sensor driver for sensing the touch by supplying one or more touch driving signals to the touch sensors and measuring a first noise of the touch sensors while the touch sensor driving signal is not supplied to the touch sensors, Sensing display. 25. The method of claim 24,
The display panel is driven in a display period for video display and a touch sensor driving period for touch sensing,
Wherein the touch sensor driver supplies the touch driving signal during a touch input sensing period of the touch sensor driving period to sense a touch,
Wherein the touch sensor driver measures the first noise during a noise measurement period of the touch sensor driving period. 25. The method of claim 24,
Wherein the touch sensor driver measures a second noise while the touch sensor driving signal is not supplied to the touch sensors,
And compares the first noise with the second noise, and adjusts the operating frequency of the touch sensor driver based on the comparison result. 27. The method of claim 26,
Wherein the first noise is measured by the touch sensor driving unit while the touch sensor driving unit is driven at a first frequency and the second noise is measured by the touch sensor driving unit while the touch sensor driving unit is driven at a second frequency different from the first frequency, The touch-sensitive display device according to claim 1, 25. The method of claim 24,
Wherein the touch sensor driver includes a circuit for selectively shorting the touch sensors while noise of the touch sensors is measured. 25. The method of claim 24,
The touch sensor driver
An amplifier for amplifying a signal on a sensor wiring connected to the touch sensors; And
And an integrator for integrating the signal of the amplifier,
Wherein the touch sensor driving unit senses a touch based on an output of the integrator and measures noise. 25. The method of claim 24,
A first touch sensor wiring;
A second touch sensor wiring;
A differential amplifier having a first input connected to the first touch sensor line and a second input; And
And a switch for connecting the second input terminal of the differential amplifier to the second touch sensor wiring when the touch is sensed and for connecting the second input terminal to the reference voltage source when the noise is measured. A display device including a display panel having touch sensors built in a pixel array, the display device being time-divisionally driven by a display period and a touch sensor driving period,
A display driving circuit for writing data of an input image to pixels of the pixel array during the display period; And
And a touch sensor driving circuit for driving the touch sensors during the touch sensor driving period,
The touch sensor driving period is divided into a touch input sensing period and a noise measuring period,
The touch sensor driving circuit includes:
An amplifier for amplifying a signal on sensor lines connected to the touch sensors;
An integrator for integrating an output signal of the amplifier;
A multiplexer coupling the sensor lines to the amplifier; And
And a touch sensor controller for supplying a touch sensor driving signal to the touch sensor or the amplifier to sense a touch input during the touch input sensing period and measuring a current noise received through the touch sensors during the noise measurement period,
Wherein the touch sensor driving signal is not generated during the noise measurement period. 32. The method of claim 31,
The touch sensor driver includes:
Comparing the current noise with a previous noise measured in a previous noise measurement period and changing the driving frequency of the amplifier and the integrator if the current noise is greater than the previous noise,
And maintains the driving frequency of the amplifier and the integrator at the current frequency when the current noise is less than the previous noise. 32. The method of claim 31,
The touch sensor control unit,
The sensor lines are sequentially connected to the amplifier during the touch input sensing period,
And simultaneously connects two or more sensor lines to the amplifier during the noise measurement period. 34. The method of claim 33,
The display driving circuit includes:
Supplying an AC signal having a same phase as the touch driving signal to the data lines and the gate lines of the display panel during the touch sensor driving period,
The touch sensor driving circuit includes:
And supplies an AC signal of a same level as the touch driving signal to sensor lines other than the sensor line currently sensed during the touch sensor driving period. 32. The method of claim 31,
The amplifier
An inverting input terminal connected to the sensor lines through the multiplexer;
A non-inverting input terminal to which the touch driving signal is applied during the touch input sensing period and to which a DC reference voltage is supplied during the noise measuring period;
An output terminal connected to an input terminal of the integrator; And
And a feedback capacitor and a reset switch connected in parallel between the inverting input terminal and the output terminal. 36. The method of claim 35,
Further comprising charge rejection coupled to an inverting input terminal of the amplifier,
The charge rejection may comprise:
A first switch connected to an inverting input terminal of the amplifier;
A second switch coupled to the non-inverting input terminal of the amplifier; And
And at least one capacitor connected to the first switch and the second switch,
During the touch input sensing period, the first and second switches are alternately turned on
Wherein a pulse is supplied to the capacitor during the touch input sensing period and 0V is applied to the capacitor during the noise measurement period. 32. The method of claim 31,
The touch sensor
A display device comprising a touch sensor of a magneto-capacitance type or a mutual capacitance type. 32. The method of claim 31,
A differential amplifier receiving a signal of the neighboring sensing lines and performing differential amplification of the signals of the neighboring sensor lines; And
Further comprising a switch for connecting a sensor line to a non-inverting input terminal of the differential amplifier during the touch input sensing period and for supplying a DC reference voltage to a non-inverting input terminal of the differential amplifier during the noise measurement period.

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