KR20140065602A - Touch sensing system and driving method thereof - Google Patents

Abstract

The present invention relates to a touch sensing system and an operation method thereof. The touch sensing system includes a touchscreen and a touch sensing circuit which applies operation signals to the touch sensors. An operation signal is generated by a multi-step waveform. The multi-step waveform includes: a pre-charging section which applies a first voltage to the touch sensors; a high-potential sustenance section which applies a second voltage lower than the first voltage to the touch sensors; a discharge acceleration section which applies a third voltage lower than the second voltage to the touch sensors; and a reference potential section which applies a reference voltage lower than the second voltage and higher than the third voltage to the touch sensors.

Description

TECHNICAL FIELD [0001] The present invention relates to a touch sensing system and a method of driving the touch sensing system.

The present invention relates to a touch sensing system and a driving method thereof.

A user interface (UI) enables a user (a user) to communicate with various electric or electronic devices, allowing the 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. Recently, the user interface 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. The touch sensing system of the capacitive type has advantages in that the structure of the touch screen is higher in durability and sharpness than the conventional resistive film type, and can be applied to various applications because multi-touch recognition and proximity touch recognition are possible.

The size of mobile information terminals to which the touch UI is applied is becoming larger. In addition, it is expected that a touch UI will be applied to a large display device such as a computer monitor in the future. As the size of the touch screen becomes larger, the wiring of the touch screen becomes longer, and the resistance and capacitance of the touch screen become larger, and the RC delay of the driving signal applied to the touch screen becomes larger. FIGS. 1 and 2 are diagrams illustrating such an RC delay.

As the size of the touch screen increases, the difference of the RC delay increases according to the position of the touch screen. Therefore, the amount of charge supplied to the touch sensors is changed and the discharge delay of unwanted residual charge is caused in the touch sensors. The signal-to-noise ratio (SNR) deteriorates. When the size of the touch screen is increased, the touch report rate is lowered because the sensing period is lengthened. The lower the touch report rate, the worse the touch sensitivity will be. The touch report rate refers to the speed or frequency (Hz) at which coordinates are calculated by analyzing the touch raw data obtained by sensing the touch sensors in the touch screen during the sensing period, the coordinate information is collected and transmitted to the external host system, . The higher the touch report rate is, the lower the latency between the touch input and the coordinate recognition, and the higher the touch sensitivity the user feels.

1 is a view showing a part of a mutual capacitance type touch screen (TSP). In FIG. 1, Tx1 to Tx5 are Tx lines to which a driving signal is applied, and Rx1 to Rx6 are Rx lines that receive a voltage of the touch sensors Cm. The touch screen (TSP) is connected to a read-out integrated circuit (ROIC) which drives the touch screen and receives the voltages of the touch sensors. The ROIC applies a driving signal to the Tx lines Tx1 to Tx5 and a voltage of the touch sensors Cm through the Rx lines Rx1 to Rx6. Since the RC delay is small in the touch sensors Cm which are close to the ROIC, the amount of electric charge (FIG. 2,? Q1) charged when the driving signal is applied is large. On the other hand, since the touch sensors far from the ROIC have a large RC delay, the amount of charge (FIG. 2, Q1) charged when the driving signal is applied is small. If the RC delay is large, the discharge speed of the touch sensor becomes long. Therefore, as the distance from the portion where the drive signal is applied on the touch screen is increased, the charge amount of the touch sensor Cm is small due to the RC delay and the discharge of the residual charge is delayed.

The present invention provides a touch sensing system and a driving method thereof that can cope with the enlargement of a size of a touch screen.

The touch sensing system of the present invention includes a touch screen including touch sensors; And a touch sensing circuit for applying a driving signal to the touch sensors.

The driving signal may include a precharging period for applying a first voltage to the touch sensors, a high-potential holding period for applying a second voltage lower than the first voltage to the touch sensors, a third voltage And a reference potential section for applying a reference voltage lower than the second voltage and higher than the third voltage to the touch sensors.

The method of driving the touch sensing system may include: pre-charging the touch sensors by applying a first voltage to the touch sensors; Applying a second voltage lower than the first voltage to the touch sensors to maintain the voltage of the touch sensors at a high potential voltage; Applying a third voltage lower than the second voltage to the touch sensors to accelerate the discharges of the touch sensors; And maintaining a discharge of the touch sensors by applying a reference voltage lower than the second voltage and higher than the third voltage to the touch sensors.

The present invention accelerates the charge rate of the touch sensors by precharging the touch sensors using the driving signal of the multi-step waveform, and sets the interval for accelerating the discharges of the touch sensors to speed up the discharge speed of the touch sensors. The present invention quickly and uniformly charges the charge with a sufficient charge amount to the touch sensors and discharges the unwanted residual charge in a short time. As a result, even if the size of the touch screen is increased, noise can be reduced in the touch signal and the touch sensitivity can be increased.

FIG. 1 is a view showing a part of a mutual capacitive touch screen.
FIG. 2 is a view showing a phenomenon in which the charge amount charged in the touch sensors becomes uneven due to the RC delay of the touch screen.
3 is a diagram illustrating a touch sensing system according to an embodiment of the present invention.
4 is an equivalent circuit diagram of the touch screen shown in FIG.
5 to 7 are views showing various combinations of the display panel and the touch screen.
8 is a circuit diagram showing an integrator of the Rx driving circuit.
9 is a waveform diagram showing a voltage change of the touch sensor before and after the touch.
10 is a waveform diagram showing a driving signal according to the first embodiment of the present invention.
11 is a waveform diagram showing a change in charge amount of a touch sensor by comparing a drive signal of the prior art with a drive signal of the present invention shown in FIG.
12 is a diagram illustrating an example of connection between a touch screen and a touch sensing circuit in the touch sensing system of the present invention.
13 is a diagram illustrating a method of driving a touch screen in a touch sensing system as shown in FIG.
FIG. 14 is a waveform diagram showing an example of a drive signal differently set according to the position of the touch screen shown in FIG.
15 and 16 are waveform diagrams showing driving signals according to another embodiment of the present invention.
17 is a circuit diagram showing a driving signal generator according to an embodiment of the present invention.
FIG. 18 is a waveform diagram showing on / off timings and output waveforms of the switches in the drive signal generator shown in FIG. 17; FIG.
19 is a circuit diagram showing a driving signal generator according to another embodiment of the present invention.
20 is a waveform diagram showing an output waveform of the drive signal generator in Fig.

The touch sensing system of the present invention can be implemented as a capacitive touch screen that senses a touch input through a plurality of capacitive sensors. The capacitive touch screen includes a plurality of touch sensors. Each of the touch sensors includes a capacitance in terms of an equivalent circuit. Capacitance can be divided into self capacitance or mutual capacitance. In the following embodiments, the mutual capacitance type touch screen is exemplified, but the touch sensing system of the present invention is not limited to the mutual capacitance type touch screen.

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.

3 to 7, the touch sensing system of the present invention includes a touch screen (TSP), a touch screen driving circuit, and the like. The touch screen TSP may be bonded on the upper polarizer POL1 of the display panel DIS as shown in FIG. 5 or may be formed between the upper polarizer POL1 of the display panel DIS and the upper substrate GLS1 as shown in FIG. . In addition, the touch sensors Cm of the touch screen TSP may be embedded in the lower substrate in the in-cell type together with the pixel array in the display panel DIS as shown in FIG. 7, or the substrates GLS OR FILM, As shown in FIG. Substrates of the display panel can be made of a glass substrate or a film substrate. 5 to 7, "PIX" denotes a pixel electrode of a liquid crystal cell, "GLS2" denotes a lower substrate, and "POL" and "POL2" denote lower polarizers.

The display panel (DIS) 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 diode A light emitting display (OLED), and an electrophoresis (EPD) display panel. The pixel array of the display panel DIS includes pixels formed in the pixel region defined by the data lines (D1 to Dm, m is a positive integer) and the gate lines (G1 to Gn, n is a positive integer) . TFTs (Thin Film Transistors), storage capacitors (Cst), and the like may be formed in each of the pixels. The TFTs are formed at the intersections of the data lines D1 to Dm and the gate lines G1 to Gn. A color filter array may be formed on the display panel DIS for color implementation.

The display driving circuit includes a data driving circuit 12, a scan driving circuit 14, and a 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 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 a gate pulse (or a scan pulse) synchronized with the data voltage to the gate lines G1 to Gn to select a line of the display panel DIS to which the data voltage is written.

The 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 the host system 40 And synchronizes the operation timings of the data driving circuit 12 and the scan driving circuit 14 with each other. 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 screen TSP includes Tx lines (Tx1 to TxN, N is a positive integer), Rx lines (Rx1 to RxM, M are positive integers) intersecting with Tx lines (Tx1 to TxN) And MxN touch sensors Cm formed at intersections of the Rx lines Rx1 to RxM and the Rx lines Tx1 to TxN. Each of the touch sensors Cm includes mutual capacities.

The touch screen driving circuit includes a touch sensing circuit (30) and a coordinate calculation unit (36). The touch screen driving circuit supplies a driving signal to the touch screen TSP to sense the voltage change of the touch sensors and transmits coordinate information of the touch input position to the host system 40.

The host system 40 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 40 includes a system on chip (SoC) with a built-in scaler to convert the digital video data RGB of the input image into a format suitable for display on the display panel DIS. The host system 40 transmits the timing signals Vsync, Hsync, DE, and MCLK to the timing controller 20 together with the digital video data. The host system 40 also executes an application program associated with the coordinate information XY of the touch data input from the coordinate calculator 36. [

The touch sensing circuit 30 includes a Tx driving circuit 32, an Rx driving circuit 34, a Tx / Rx controller 38, and the like.

The touch sensing circuit 30 applies a driving signal to the touch sensors through the Tx lines Tx1 to TxN using the Tx driving circuit 32 in the normal operation mode and applies the driving signals to the Rx lines Rx1 RxM) and the Rx driving circuit 34 to output touch raw data, which is digital data, by sensing the voltage of the touch sensors Cm. The driving signal is generated in the waveforms of FIGS. 10 and 12 to 16 in order to rapidly increase the charge amount of the touch sensors Cm and to increase the discharge speed. The touch sensing circuit 30 can be integrated into one ROIC. In addition, the touch sensing circuit 30 and the coordinate calculation unit 36 can be integrated into one touch IC.

The Tx driving circuit 32 selects the Tx channel to output the driving signal in response to the Tx setup signal from the Tx / Rx controller 38 in the normal operation mode, selects the Tx line Tx1 to TxN connected to the selected Tx channel, As shown in FIG. The Tx lines Tx1 to TxN are charged during the high potential section of the driving signal to supply charge to the touch sensors Cm and are discharged in the low potential section of the driving signal. The drive signal is applied to the capacitors (FIG. 8, Cs) of the integrator incorporated in the Rx driving circuit 34 via the Rx lines Rx1 to RxM through N (N is 2 or more And can be continuously supplied N times to each of the Tx lines Tx1 to TxN so as to be accumulatively accumulated for a predetermined number of times.

The Rx driving circuit 34 accumulates the touch sensor voltage in the capacitor Cs of the integrator in synchronization with the driving signal and supplies the accumulated voltage to an analog-to-digital converter And outputs the touch raw data. When the touch sensor is touched before and after the touch, the capacitance value (C) of the touch sensor decreases at Q (charge) = C (capacitance) × V Is larger than other sensors without touch input. Accordingly, it is possible to determine whether or not touch input is performed in accordance with the change of the touch sensor voltage before and after the touch. The Rx drive circuit 34 converts the touch sensor voltage changes before and after the touch into the touch raw data which is digital data and supplies the touch raw data to the coordinate calculation section 36. [ 8 and 9, "Vd" is the voltage of the driving signal. "OP" is an operational amplifier of the integrator. 11 is a waveform example in which the voltage of the touch sensor is accumulated in the integrator before touching, and 12 is a waveform example in which the voltage of the touch sensor is accumulated in the integrator after touching.

The coordinate calculation unit 36 executes a preset touch recognition algorithm to compare the touch primitive data received from the Rx driving circuit 34 in a normal operation mode with a preset threshold value. Any known algorithm for the touch recognition algorithm is possible. The touch recognition algorithm detects touch primitive data above a threshold value. The touch primitive data exceeding the threshold value is determined as touch data obtained from the touch sensors in which the touch input is generated. The coordinate calculation unit 36 executes a touch recognition algorithm, assigns an identification number to each touch data that is equal to or larger than the threshold value, and calculates coordinates. Then, the coordinate calculation unit 36 transmits the identification number and coordinate information of the touch data equal to or greater than the value of the letter to the host system 40. The coordinate calculation unit 36 may be implemented as an MCU (Micro Controller Unit).

10 is a waveform diagram showing driving signals of the touch screen according to the first embodiment of the present invention. FIG. 11 is a waveform diagram showing a change in charge amount of the touch sensors by comparing the drive signal (a) of the prior art with the drive signal (b) of the present invention shown in FIG.

10 and 11, the driving signal of the present invention is a multi-step waveform including a precharging period t1, a high potential holding period t2, a discharging acceleration period t3, and a reference potential period t4 .

The precharging period t1 is a period in which the positive polarity precharge voltage Vpre higher than the high potential driving voltage Vd is directly applied to the touch sensors Cm. The touch sensors Cm rapidly charge the charge during the precharging period t1 as shown in FIG. 11 (b). The conventional driving signal charges the touch sensors Cm with the high potential driving voltage Vd without the precharging period t1 as shown in FIG. In Fig. 11,? Q is a charge amount charged in the touch sensors. The high potential driving voltage Vd may be set to a voltage between 2 and 3 (V). The precharging voltage Vpre is appropriately selected in accordance with the precharging effect and the width W of the driving signal.

The high-potential holding period t2 charges the touch sensors Cm by applying the high-potential driving voltage Vd directly to the touch sensors Cm. The voltage of the touch sensors Cm is rapidly increased to the precharging period t1 and then discharged to the high potential driving voltage Vd during the high potential holding period t2 as shown in FIG. do.

The discharge acceleration period t3 applies the reverse polarity discharge voltage Vdis directly to the touch sensors Cm to discharge the charges of the touch sensors Cm. The touch sensors Cm rapidly discharge the charge during the discharge acceleration period t3 as shown in FIG. 11 (b).

The reference potential section t4 directly applies the low potential reference voltage Vref to the touch sensors Cm to discharge the charges of the touch sensors Cm. The low potential reference voltage Vref is set to a voltage lower than the high potential driving voltage Vd and higher than the reverse polarity discharge voltage Vdis. The low potential reference voltage Vref may be set to the ground voltage (GND) or 0V. The touch sensors Cm discharge to the low potential reference voltage Vref during the reference potential section t4.

11 (a) and 11 (b), the present invention can sufficiently increase the amount of charge ΔQ of the touch sensors Cm within a short time by using the precharging effect, The discharge voltage can be applied to the touch sensors Cm to discharge the touch sensors Cm within a short time. Therefore, the present invention can supply enough charge uniformly to the touch sensors Cm even on a touch screen (TSP) having a large RC delay, and quickly discharges the touch sensors Cm to reduce noise in the touch signal to reduce the signal- SNR) can be improved. Furthermore, since the charging time and discharging time of the touch sensors Cm can be reduced to reduce the width W of the driving signal, the touch sensitivity can be increased by reducing the touch report rate.

The touch sensing circuit 30 is generally disposed at a position close to any one of the touch screens TSP as shown in FIG. Since the touch sensing circuit 30 and the touch screen TSP are connected to each other, the RC delay of the touch screen TSP becomes larger as the distance from the touch sensing circuit 30 increases. The touch sensing system of the present invention may consider a RC delay having a variation depending on the position of the touch screen TSP and consider the RC delay of the driving signal according to the position of the touch screen TSP as shown in FIGS. 13 and 14, And the reverse polarity discharge voltage Vdis can be set differently.

13 and 14, the touch screen TSP may be divided into a plurality of blocks B1 to B3. Each of the blocks B1 to B3 includes two or more Tx lines to which a driving signal is applied. 13 shows an example in which the touch screen TSP is divided into three blocks B2 to B3, the number of block divisions is not limited to three.

The RC delay of the first block B1 is close to the touch sensing circuit 30 and is smaller than the other blocks B2 and B3. On the other hand, the RC delay of the third block B3 is the largest because it is far from the touch sensing circuit 30. [ The RC delay of the second block B2 is larger than the first block B1 and smaller than the third block B3. The RC delay difference of each block makes the charge / discharge characteristics of the touch sensors Cm different. For example, the charge / discharge time of the touch sensor Cm formed at a position where the RC delay is small is relatively long, whereas the charge / discharge time of the touch sensor Cm formed at a position where the RC delay is large is relatively long.

The touch sensing system of the present invention can set the precharging voltage Vpre and the reverse polarity discharge voltage Vdis differently for each of the blocks divided in the touch screen TSP as shown in FIG. The precharging voltage Vpre and the reverse polarity discharge voltage Vdis are set to a voltage proportional to the RC delay.

When the touch screen TSP is divided and driven into a plurality of blocks B1 to B3 as shown in FIG. 13, the driving signals applied to the blocks B1 to B3 are shifted from the precharging voltage Vpre The polarity discharge voltage (Vdis) is proportional to the RC delay of the touch screen (TSP). For example, the precharging voltage Vpre and the reverse polarity discharge voltage Vdis of the driving signal applied to the Tx lines of the first block B1 are set to be smaller or smaller than the other blocks B2 and B3 . The drive signal applied to the first block B1 may be set to the same waveform as the drive signal of the prior art. The precharging voltage Vpre and the reverse polarity discharge voltage Vdis of the driving signal applied to the Tx lines of the third block B3 are set to be larger than those of the other blocks B1 and B2. The precharging voltage Vpre and the reverse polarity discharge voltage Vdis of the driving signal applied to the Tx lines of the second block B2 are set to be larger than the first blocks B1 and B2 and smaller than the third block B3 do.

The driving signal of the present invention can be modified as shown in FIGS. 15 and 16 according to the size of the touch screen (TSP) and the charge / discharge characteristics. In the example of Fig. 15, the driving signal of the present invention is generated in a multi-step waveform divided into a precharging period t1, a high-potential sustaining period t2, and a reference potential period t4 without a discharging acceleration period t3 . In the example of Fig. 16, the driving signal of the present invention is generated in a multi-step waveform divided into a high-potential holding period t2, a discharge acceleration period t3, and a reference potential period t4 without a precharging period t1 .

17 is a circuit diagram showing an example of a drive signal generator according to an embodiment of the present invention. This drive signal generator may be incorporated in the Tx drive circuit 32. [ FIG. 18 is a view showing on / off timing of switches in the drive signal generator shown in FIG.

17 and 18, the drive signal generator includes a plurality of switches S0 to S3. The switches SO to S3 may be implemented with a transistor, for example, a metal-oxide semiconductor field effect transistor (MOSFET). These switches S0 to S3 are controlled by the Tx / Rx controller 38. [

The first switch S0 supplies the low potential reference voltage Vref to the output terminal of the drive signal generator in response to the first control signal CTRL0. The output terminal is connected to the Tx line. The second switch S1 supplies the first voltage V1 to the output terminal in response to the second control signal CTRL1. The first voltage V1 may be selected as the positive precharge voltage Vpre described above. The third switch S2 supplies the second voltage V2 to the output terminal in response to the third control signal CTRL2. The second voltage V2 may be selected as the above-mentioned high potential driving voltage Vd. The fourth switch S3 supplies the third voltage V3 to the output terminal in response to the fourth control signal CTRL3. The third voltage V3 may be selected as the above-described reverse polarity discharge voltage Vdis. The switches S0 to S3 are turned on when the control signals CTRLO to CTRL3 are at a high logic voltage. The control signals CTRLO to CTRL3 are sequentially generated as a high logic voltage H as shown in Fig. Accordingly, the switches S0 to S3 are sequentially turned on to generate the driving signals as shown in FIG. 10 and FIGS. The driving signal includes a precharging period for applying the first voltage V1 to the touch sensors Cm and a high voltage holding period for applying the second voltage V2 lower than the first voltage V1 to the touch sensors Cm A discharge acceleration period for applying a third voltage V3 lower than the second voltage V2 to the touch sensors Cm and a reference voltage Vref lower than the second voltage V2 and higher than the third voltage V3, ) To the touch sensors (Cm). The second switch S1 or the fourth switch S3 may be omitted in the case of the drive signals as shown in Figs.

The driving method of the touch sensing system according to the embodiment of the present invention applies the first voltage V1 to the touch sensors Cm using the driving signal of the multi-step waveform as described above to pre-charge the touch sensors Cm , Applying a second voltage (V2) to the touch sensors (Cm) to maintain the voltage of the touch sensors (Cm) at a high potential, applying a third voltage (V3) to the touch sensors (Cm) And accelerating the discharge of the touch sensors Cm by applying a reference voltage Vref to the touch sensors Cm to maintain the discharge of the touch sensors Cm.

A resistor R and a capacitor C may be connected between the output terminal of the driving signal generator and the ground voltage source GND. The resistor R and the capacitor C eliminate noise such as ripple to stabilize the output voltage. The adder 61 and the waveform generator 62 may be connected to the output terminal of the drive signal generator. The waveform generator 62 can generate waveforms such as sinusoidal waves, triangular waves, and sawtooth waves. The adder 61 adds the output of the waveform generator 62 to the voltage of the multi-step waveform applied from the drive signal generator. When the output of the waveform generator 62 is sinusoidal, the output of the adder 61 is as shown in Fig. As described above, the driving signal of the present invention can be modified into various forms based on the multi-step waveform as shown in FIG.

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.

DIS: Display panel TSP: Touch screen
12: Data driving circuit 14: Scan driving circuit
20: timing controller 30: touch sensing circuit
32: Tx driving circuit 34: Rx driving circuit
36: Coordinate calculation unit

Claims (10)

A touch screen including touch sensors; And
And a touch sensing circuit for applying a driving signal to the touch sensors,
The driving signal may include a precharging period for applying a first voltage to the touch sensors, a high-potential holding period for applying a second voltage lower than the first voltage to the touch sensors, a third voltage And a reference potential section for applying a reference voltage, which is lower than the second voltage and higher than the third voltage, to the touch sensors, wherein the touch acceleration is applied to the touch sensors. Sensing system. The method according to claim 1,
Wherein the third voltage is a voltage having a polarity opposite to the polarity of the first and second voltages. 3. The method of claim 2,
The touch screen is divided into a plurality of blocks,
Each of the blocks including two or more lines to which the driving signal is applied,
Wherein the first and third voltages in one block are equal,
Wherein the first and third voltages are set to different voltages between the blocks. The method of claim 3,
Wherein the first and third voltages are proportional to the RC delay of the touch screen. 5. The method of claim 4,
Wherein the first and third voltages are set to be smaller or smaller than the first and third voltages applied to the other blocks in the driving signal applied to the first block closest to the touch sensing circuit. system. 6. The method of claim 5,
Wherein in the driving signal applied to the third block farthest from the touch sensing circuit, the first and third voltages are greater than the first and third voltages applied to the other blocks. The method according to claim 6,
In the driving signal applied to the second block located between the first block and the third block, the first and third voltages are larger than the first and third voltages applied to the first block, Is less than the first and third voltages applied to the touch sensing system. A touch screen including touch sensors; And
And a touch sensing circuit for applying a driving signal to the touch sensors,
A driving signal applied to the touch sensors includes a precharging period for applying a first voltage to the touch sensors, a high potential holding period for applying a second voltage lower than the first voltage to the touch sensors, And a reference potential section for supplying a reference voltage lower than the reference voltage to the touch sensors. A touch screen including touch sensors; And
And a touch sensing circuit for applying a driving signal to the touch sensors,
The driving signal applied to the touch sensors may include a high-level sustain period for applying a first voltage to the touch sensors, a discharge accelerating period for applying a second voltage lower than the first voltage to the touch sensors, And a reference potential section that is lower than the first voltage and supplies the reference voltage higher than the second voltage to the touch sensors. A method of driving a touch sensing system including a touch screen including touch sensors and a touch sensing circuit for applying a driving signal to the touch sensors,
Applying a first voltage to the touch sensors to pre-charge the touch sensors;
Applying a second voltage lower than the first voltage to the touch sensors to maintain the voltage of the touch sensors at a high potential voltage;
Applying a third voltage lower than the second voltage to the touch sensors to accelerate the discharges of the touch sensors; And
And maintaining a discharge of the touch sensors by applying a reference voltage lower than the second voltage and higher than the third voltage to the touch sensors.

Images