KR20170079666A - Touch sensing system - Google Patents

Abstract

A touch driving apparatus of the present invention includes a display panel including a pixel array having touch sensors built therein, a touch panel for driving the touch sensors during a touch interval, and a touch section for driving the touch sensors within one display frame period for displaying an input image (K is a positive integer) display frame to the first touch reporter point of the Kth display frame, the first period including the K + 1 And a second period from the start point of the display frame to the first touch reporter point of the (K + 1) th display frame.

Description

Touch sensing system {TOUCH SENSING SYSTEM}

The present invention relates to a touch sensing system including a capacitive touch sensor.

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

The touch UI is essential for portable information devices. The touch UI is implemented by a method of forming a touch screen on the screen of a display device. Such a touch screen can be implemented in a capacitive manner. A touch screen having a capacitive touch sensor senses touch input by sensing capacitance change, that is, change in charge of a touch sensor when a finger or a conductive material contacts (or is proximate to) the touch sensor.

The capacitive touch sensor may be implemented as a self capacitance sensor or a mutual capacitance sensor. Each of the electrodes of the capacitance sensor may be connected in a one-to-one relationship with sensor wirings formed along one direction. A mutual capacitance sensor may be formed between neighboring sensor electrodes.

Referring to Fig. 1, wires 4 are connected to electrodes 2 of a magnetic capacitance sensor Cs. The capacitance sensor Cs includes a capacitance formed in each of the electrodes 2. When the touch driving signal is applied to the electrode 2 through the wiring 4, the charge Q is accumulated in the capacitance sensor Cs. At this time, when a finger or a conductive object is brought into contact with the electrode 4, the capacitance Cf is further connected to the capacitance sensor Cs to change the capacitance value of the capacitance sensor Cs. Accordingly, since the capacitance value between the finger-touched sensor and the non-touched sensor is different, it is possible to determine whether or not the finger is touched.

The touch sensing system using the capacitance sensor Cs as shown in FIG. 1 has a problem that the number of wires 4 connected to the capacitance capacitors Cs is large, (Dead zone) is large. The dead zone is an area where the touch input can not be sensed.

In the touch sensing system using the conventional capacitive sensor, since the dead zone is large, the electrodes of the sensors can not be formed densely and the touch resolution is low accordingly. If the number of touch sensors is increased in order to increase the touch resolution, the number of the wirings 14 also increases, and the dead zone becomes larger. As a result, in the conventional touch sensing system, it is difficult to improve the resolution due to the structural problem of the capacitive sensor, and it is difficult to improve the sensitivity and the accuracy of the sensing. Further, when the number of touch sensors is increased in the conventional touch sensing system, the number of channels of a touch sensing integrated circuit (hereinafter referred to as "IC") increases and the size of the IC chip increases.

SUMMARY OF THE INVENTION Accordingly, it is an object of the present invention to provide a touch sensing system capable of increasing touch hashing, sensing sensitivity, and accuracy without increasing the number of touch sensors.

In order to achieve the above object, the touch sensing system of the present invention includes capacitive sensors provided on each of the sensor electrodes, mutual capacitance sensors provided between neighboring sensor electrodes, and sensor wirings connected to the sensor electrodes Sensing a touch input to the capacitive sensors according to a first touch drive signal in a first sensing mode and sensing a touch input to the capacitive sensors in a second sensing mode in response to a second touch drive signal in a first sensing mode, And a touch driving circuit for sensing the touch input. Here, the touch driving circuit may include: a sensing unit for sensing the touch input; a multiplexer for selectively connecting a first input terminal of the sensing unit to one of the sensor wiring lines; A driving signal selector for applying a touch driving signal to sensor wirings not connected to the sensing unit and applying the second touch driving signal to the sensor wiring connected to the sensing unit in the second sensing mode, And a reference signal selector for applying the first touch driving signal to the second input terminal of the sensing unit in the sensing mode and applying the reference voltage to the second input terminal of the sensing unit in the second sensing mode.

In the second sensing mode, a base voltage or a direct voltage is applied to the sensor wirings other than the first sensor wiring to which the second touch driving signal is applied and the second sensor wiring to be connected to the first input terminal of the sensing unit.

In the second sensing mode, the sensor electrode connected to the first sensor wiring and the sensor electrode connected to the second wiring are adjacent to each other.

The sensing unit may include a radar sensing unit for selectively sensing a touch input to the radar sensor electrodes connected to the radar sensor wirings of the sensor wirings, And an odd-numbered sensing unit for selectively sensing a touch input to the odd-numbered sensing unit, wherein the multiplexer further comprises: a radix multiplexer for selectively connecting a first input of the odd-numbered sensing unit to one of the odd- And an even multiplexer for selectively connecting an input terminal to any one of the even sensor wirings, wherein the odd sensing unit and the superior sensing unit are operated simultaneously, and the odd multiplexer and the even multiplexer operate simultaneously.

Wherein the touch driving circuit applies the first touch driving signal to the first sensor electrode and the second sensor electrode which are adjacent to each other in the first sensing mode and applies the first touch driving signal to the first capacitive sensor provided to the first sensor electrode Sensing the touch input through the first sensor electrode and sensing the touch input to the second capacitive sensor provided on the second sensor electrode through the second sensor electrode.

Wherein the sensor electrodes include a first sensor electrode, a second sensor electrode adjacent to the first sensor electrode, a third sensor electrode adjacent to the second sensor electrode, a fourth sensor electrode adjacent to the third sensor electrode, And the fifth sensor electrode adjacent to the fourth sensor electrode, the touch driving circuit applies the second touch driving signal to the second sensor electrode in the second sensing mode, Sensing the touch input of the first mutual capacitance sensor provided between the second sensor electrodes through the first sensor electrode and applying the second touch driving signal to the fifth sensor electrode, Sensing the touch input to the second mutual capacitance sensor provided between the third sensor electrode and the fifth sensor electrode through the fourth sensor electrode, and applying a base voltage or a DC voltage to the third sensor electrode.

The sensor electrodes are arranged in the order of a first sensor electrode, a second sensor electrode adjacent to the first sensor electrode, a third sensor electrode adjacent to the second sensor electrode, and a fourth sensor electrode adjacent to the third sensor electrode The touch driving circuit applies the second touch driving signal to the second sensor electrode in the second sensing mode and outputs the first touch sensing signal to the first inter-capacitive sensor provided between the first sensor electrode and the second sensor electrode, Sensing the touch input to the first sensor electrode through the first sensor electrode and applying the second touch driving signal to the third sensor electrode to sense the second inter- The touch input to the sensor is sensed through the fourth sensor electrode.

The touch driving circuit alternately senses the first sensing mode and the second sensing mode by the capacitive sensors and the mutual capacitance sensors.

The touch driving circuit alternately senses the first sensing mode and the second sensing mode for each of the capacitive sensors and the mutual capacitive sensors.

The touch sensing system of the present invention senses a touch input at each of sensor electrodes using capacitive sensors and senses a touch input between sensor electrodes using capacitive sensors to increase the number of touch sensors The resolution, sensing sensitivity and accuracy of the touch screen can be improved.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a view showing electrodes and a wiring structure of a touch screen including capacitive sensors. FIG.
2 is a block diagram illustrating a touch sensing system in accordance with an embodiment of the present invention.
3 is a diagram illustrating an example in which a touch sensor is embedded in a pixel array;
4 is a timing diagram showing a method of driving time-divisionally driving pixels and touch sensors of the display panel as shown in FIG.
Figures 5 and 6 show the multiplexers and sensing units connected to the touch sensors.
7 is a diagram for explaining signals applied to a multiplexer and a sensing unit in a first sensing mode for sensing capacitance variation of the capacitive sensors;
8 is a view for explaining signals applied to a multiplexer and a sensing unit in a second sensing mode for sensing capacitance variation of mutual capacitance sensors;
FIGS. 9 to 11 illustrate the sensing channel selection procedure of the multiplexers in the first sensing mode and corresponding sensing electrodes. FIG.
FIGS. 12 to 14 illustrate a sensing channel selection sequence of the multiplexers in the second sensing mode and corresponding sensing electrodes. FIG.
FIGS. 15 through 17 illustrate another sensing channel selection procedure of the multiplexers in the second sensing mode, and FIGS.
18 is a view showing an example in which the capacitive sensors and the mutual capacitive sensors are alternately sensed in a touch interval.
19 is a view showing an example in which the capacitive sensors and the mutual capacitive sensors are all alternately sensed in the touch section.

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.

2 shows a touch sensing system according to an embodiment of the present invention. 3 shows an example in which a touch sensor is embedded in a pixel array. 4 illustrates a method of driving the pixels and the touch sensors of the display panel in a time division manner as shown in FIG.

2 to 4, the touch sensing system of the present invention includes a display device and a touch module.

The display device includes a liquid crystal display (LCD), a field emission display (FED), a plasma display panel (PDP), an organic light emitting diode (OLED) , An electrophoresis display device (Electrophoresis, EPD), or the like. In the following embodiments, the display device is implemented as a liquid crystal display device, but the display device of the present invention is not limited to the liquid crystal display device.

The display device may include a display panel (DIS), a display drive circuit (12, 14, 16), and a host system (19).

The display panel DIS includes a liquid crystal layer formed between two substrates. 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) . Each of the pixels includes a TFT (Thin Film Transistor) formed at intersections of the data lines D1 to Dm and the gate lines G1 to Gn, a pixel electrode for charging a data voltage, A storage capacitor (Cst) for maintaining a voltage, and the like.

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

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

The display driving circuit includes a data driving circuit 12, a gate driving circuit 14, and a timing controller 16, and writes video data of an input image to pixels of the display panel DIS. The data driving circuit 12 converts the digital video data RGB input from the timing controller 16 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 gate drive 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 the pixel line of the display panel DIS to which the data voltage is written.

The timing controller 16 inputs timing signals 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 19 And synchronizes the operation timings of the data driving circuit 12 and the gate 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 host system 19 transmits the timing signals Vsync, Hsync, DE and MCLK together with the digital video data RGB to the timing controller 16 and the touch coordinate information XY ). ≪ / RTI >

The touch module includes a touch screen (TSP) and a touch driving circuit (18).

The touch screen TSP includes a plurality of sensor electrodes C1 to C4 and sensor wirings L1 to L4 connected to the sensor electrodes C1 to C4, respectively. The touch sensors of the touch screen TSP are divided into capacitance capacitors Cs having self capacitance and mutual capacitance sensors Cm having mutual capacitance. A capacitance sensor Cs is formed in each of the sensor electrodes C1 to C4 and a mutual capacitance sensor Cm is formed in the neighboring sensor electrodes C1 to C4.

The capacitance sensing method applies a touch driving signal TX to each of the sensor electrodes C1 to C4 through the sensor wirings L1 to L4 to supply charges to the capacitance sensor Cs. Then, when sensing capacitance change of the capacitance sensor Cs through the sensor electrodes C1 to C4 and the sensor lines L1 to L4 to which the touch driving signal TX is applied, the touch on the sensor electrodes C1 to C4 The input can be sensed.

The mutual capacitance sensing method applies a touch driving signal TX to one of the sensor electrodes (Tx in FIGS. 12 and 15) of the neighboring sensor electrodes C1 to C4 through the sensor wirings L1 to L4 And supplies the electric charge to the mutual capacitance sensor Cm and outputs the capacitance of the mutual capacitance sensor Cm through another sensor electrode (Rx in Figs. 12 and 15, etc.) and the sensor wiring in synchronization with the touch driving signal TX Sensing the change, it is possible to sense the touch input located between neighboring sensor electrodes. The mutual capacitance sensing method can sense the touch input on the sensor wirings (L1 to L4).

Such a mutual capacitance sensing method can sense the touch input at each position between the sensor electrodes C1 to C4. Accordingly, the touch sensing system of the present invention not only can sense the touch input at each of the sensor electrodes using the capacitive sensors, but also senses the touch input among the sensor electrodes using mutual capacitance sensors, The sensing sensitivity and accuracy can be improved.

The touch screen TSP may be bonded onto the upper polarizer plate of the display panel DIS or between the upper polarizer plate of the display panel DIS and the upper substrate. In addition, the touch sensors (C1 to C4) of the touch screen (TSP) can be embedded as an in-cell type in the pixel array of the display panel (DIS). An example in which the touch screen TSP is embedded in the pixel array of the display panel DIS is shown in Fig. 3, the pixel array of the display panel DIS includes touch sensors C1 to C4 and sensor lines L1 to Li connected to the touch sensors C1 to C4, Positive integer). The common electrode COM of the pixels 101 is divided into a plurality of segments. The touch sensors C1 to C4 are implemented as a divided common electrode COM. One common electrode segment is connected in common to the plurality of pixels 101 and forms one touch sensor. Accordingly, the touch sensors C1 to C4 supply the common voltage Vcom to the pixels 101 during the display periods Td1 and Td2 for writing the image data as shown in FIG. 4, and the touch periods Tt1 and Tt2 And receives the touch driving signal TX to sense the touch input.

The touch driving circuit 18 applies the touch driving signal TX to the touch sensors C1 to C4 and senses the capacitance change and mutual capacitance change of the touch sensors C1 to C4, Pen) and the location of the conductive material.

The touch driving circuit 18 drives the touch sensors C1 to C4 during the touch periods Tt1 and Tt2 in response to the touch enable signal TEN input from the timing controller 16 or the host system 19 . The touch driving circuit 18 supplies the touch driving signal TX to the touch sensors C1 to C4 through the sensor wirings L1 to L4 during the touch periods Tt1 and Tt2 to sense the touch input. The touch driving circuit 18 determines the touch input by analyzing the capacitance change of the touch sensor depending on the presence or absence of the touch input, and calculates coordinates of the touch input position. The coordinate information of the touch input position is transmitted to the host system 19 in the form of a touch reporter.

The touch driving circuit 18 drives the touch sensors C1 to C4 in response to the touch enable signal TEN during the touch periods Tt1 and Tt2, At least two touch frames for driving the touch panels C1 to C4 can be allocated to increase the touch report rate than the display frame rate. Here, within one touch frame, a plurality of touch intervals corresponding to the number of the plurality of multiplexers may be included.

For example, if the display periods Td1 and Td2 and the touch intervals Tt1 and Tt2 are divided into a plurality of intervals as shown in FIG. 4 within one frame period, the touch driving circuit 18 outputs the touch interval Tt1 And Tt2, and transmits coordinate information of the touch input to the host system 19 at the time when each touch frame is completed. Accordingly, the present invention can further increase the touch report rate than the display frame rate. The display frame rate is the frame frequency at which one frame image is written to the pixel array. The touch reporter rate is the speed at which coordinate information of the touch input is generated. The higher the touch reporter rate is, the faster the coordinate recognition speed of the touch input becomes, thereby improving the touch sensitivity.

FIGS. 5 and 6 show the multiplexers 140 and the sensing units 160 connected to the sensor electrodes 22. FIG. 7 is a view for explaining a signal applied to the multiplexer and the sensing unit in the first sensing mode for sensing capacitance change of the capacitive sensors. 8 is a diagram for explaining a signal applied to the multiplexer and the sensing unit in the second sensing mode for sensing capacitance variation of mutual capacitance sensors.

5 and 6, the touch driving circuit 18 may include an MCU (Micro Controller Unit) for controlling the operation of the multiplexers 140 and the sensing units 160. Referring to FIG. The MCU can be replaced by a touch IC.

The multiplexer 140 selectively connects the sensing unit 160 and the sensor electrodes 22 under the control of the MCU. The multiplexer 140 can supply the common voltage Vcom under the control of the MCU. When the resolution of the touch screen is M (horizontal) x N (vertical) (each of M and N is a positive integer of 2 or more), the number of required multiplexers 140 may be M. When the resolution of the touch screen is MxN, the sensor electrodes 12 may be divided into MxN. Each of the multiplexers 140 is connected to N sensor electrodes 22, Y1 to Yn via N sensor wirings 115 and N sensor wirings 115 are sequentially connected to one sensing unit 160 .

The sensing unit 160 is connected to the sensor wirings 115 via the multiplexer 140 and converts sensing signals received from the sensor electrodes 12 into digital data. The sensing unit 160 includes an amplifier for amplifying the received sensing signal, an integrator for accumulating the voltage of the amplifier, and an analog-to-digital converter (ADC) for converting the voltage of the integrator into digital data ). The digital data output from the ADC is transferred to the MCU as touch raw data. When the resolution of the touch screen is M x N, the number of sensing units 160 may also be required.

The MCU compares the data with a predetermined threshold value by touching and determines the position of the touch sensor having a charge variation amount larger than the threshold value as the touch input area. The MCU calculates coordinates for each of the touch inputs and transmits touch data (TDATA) including the touch input coordinate information to the host system (19).

The touch driving circuit 18 is connected to the driving power source to receive driving power. The touch driving circuit 18 generates a touch driving signal TX at the touch intervals Tt1 and Tt2 by considering the touch enable signal TEN and applies the generated touch driving signal TX to the sensor electrodes 22. [ The touch driving signal TX may be generated in various forms such as a square wave type pulse, a sinusoidal wave, and a triangular wave, but it is preferably implemented as a square wave. The touch driving signal may be applied to each of the sensor electrodes 22 a plurality of times so that charge can be accumulated in the integrator of the sensing unit 160 a plurality of times.

The touch driving circuit 18 generates a sensing mode control signal CTRL at the touch intervals Tt1 and Tt2 to generate a first sensing mode for sensing a capacitance change of the capacitive sensors And a second sensing mode (hereinafter referred to as "mutual sensing mode") for sensing a capacitance change of the mutual capacitance sensors. The touch driving circuit 18 generates the first touch driving signal TXS in the self-sensing mode and the second touch driving signal TXM in the mutual sensing mode. The first touch driving signal TXS and the second touch driving signal TXM may have the same shape or different shapes.

The touch driving circuit 18 outputs the first touch driving signal TXS in the self sensing mode to the sensor wirings 115 not connected to the first input terminal of the sensing unit 160 (the (-) input terminal of the amplifier Amp) And applies a second driving signal TXM to the sensor wiring 115 connected to the first input terminal (the negative input terminal of the amplifier Amp) of the sensing unit 160 in the mutual sensing mode (Not shown). The touch driving circuit 18 applies the first touch driving signal TXS to the second input terminal (the (+) input terminal of the amplifier Amp) of the sensing unit 160 in the self-sensing mode, And a reference signal selection unit 220 for applying the reference voltage VREF to the second input terminal of the sensing unit 160 (the (+) input terminal of the amplifier Amp).

A case where the capacitance sensor Cs of the sensor electrode Y1 is sensed in the self-sensing mode will be described with reference to FIG. In the self-sensing mode, when the first touch driving signal TXS is applied to the first input terminal of the sensing unit 160 (the negative input terminal of the amplifier Amp), the multiplexer 140 outputs the first touch driving signal TXS is selectively applied to only the sensor wiring connected to the sensor electrode Y1. Then, the sensing unit 160 senses the potential change of the sensor electrode Y1 according to the first touch driving signal TXS through the sensor wiring and the multiplexer 140. The multiplexer 140 is connected to the sensor wirings not connected to the first input terminal (the negative input terminal of the amplifier Amp) of the sensing unit 160, that is, the sensor wirings connected to the other sensor electrodes Y2 to Yn It is possible to prevent the sensing signal from being distorted due to non-sensed sensor wirings by applying the first touch driving signal TXS. For this purpose, a certain DC voltage may be applied to the sensor wirings connected to the other sensor electrodes Y2 to Yn in addition to the first touch driving signal TXS.

Referring to FIG. 8, a case where the mutual capacitance sensor Cm between the sensor electrodes Y1 and Y2 is sensed in the mutual sensing mode will be described. In the mutual sensing mode, the multiplexer 140 selectively applies the second touch driving signal TXM only to the sensor wiring connected to the sensor electrode Y2. The sensing unit 160 senses the potential change of the sensor electrode Y1 according to the second touch driving signal TXM through the sensor wiring connected to the sensor electrode Y1 and the multiplexer 140. [ On the other hand, the multiplexer 140 prevents the sensing signal from being distorted due to sensor wires that are not sensed by applying a base voltage or a DC voltage to sensor wirings that are not connected to the sensor electrodes Y1 and Y2 .

FIGS. 9 to 11 show the sensing channel selection procedure of the multiplexers in the self-sensing mode and the electrodes to be sensed according to the selection order.

Referring to FIG. 9, the touch driving circuit 12 of the present invention can simultaneously sense two neighboring sensor electrodes in the self-sensing mode. In other words, the touch driving circuit 12 applies the first touch driving signal TXS to the first sensor electrode Y1 and the second sensor electrode Y2, which are adjacent to each other, The touch input to the first capacitive sensor is sensed through the first sensor electrode Y1 and the touch input to the second capacitive sensor provided in the second sensor electrode Y2 is sensed through the second sensor electrode Y1, Y1).

For this purpose, the sensing unit 160 of FIG. 6, which is responsible for the sensing of the one-column sensor electrodes, performs touch input to the ninth sensor electrodes Y1, Y3, ..., Y23 connected to the sensor wires of the sensor wires (Y2, Y4, ..., Y22) connected to the sensor wirings among the sensor wirings, and a sensor for selectively sensing touch inputs to the sensor electrodes And a sensing unit (AFE). The multiplexer 140 of FIG. 6, which is responsible for sensing one row of sensor electrodes, includes a radix multiplexer MUXO (-) for selectively connecting the first input terminal (-) of the radix sensing unit And an even multiplexer (MUXE) for selectively connecting the first input terminal (-) of the abscissa sensing unit (AFE) to any one of the sensor wiring lines. Here, the radix sensing unit AFE and the superior sensing unit AFE operate simultaneously, and the radix multiplexer MUXO and the fine multiplexer MUXE operate simultaneously.

In the self-sensing mode as shown in FIGS. 10 and 11, 26 * 23 (598) sensor electrodes are sensed through a total of 12 sensing operations. The sensor electrodes Y1 and Y2 are simultaneously sensed at the first sensing S1 and the sensor electrodes Y3 and Y4 are simultaneously sensed at the second sensing S2. On the same principle, the sensor electrodes Y11 and Y12 are simultaneously sensed at the twelfth sensing time S12.

FIGS. 12 to 14 show the selection order of the sensing channels of the multiplexers in the mutual sensing mode and the electrodes to be sensed according to the selection order.

Referring to FIG. 12, in the mutual sensing mode, the touch driver circuit 12 of the present invention can simultaneously sense the sensor electrodes in two rows separated from each other. In other words, the sensor electrodes include a first sensor electrode Y1, a second sensor electrode Y2 adjacent to the first sensor electrode Y1, a third sensor electrode Y3 adjacent to the second sensor electrode Y2, The fourth sensor electrode Y4 adjacent to the third sensor electrode Y3 and the fifth sensor electrode Y5 adjacent to the fourth sensor electrode Y4 are arranged in this order, The touch input to the first mutual capacitance sensor formed between the first sensor electrode Y1 and the second sensor electrode Y2 is applied to the first sensor electrode Y2 by applying the second touch driving signal TXM to the second sensor electrode Y2, The first sensor electrode Y4 and the fifth sensor electrode Y5 are connected to the fifth sensor electrode Y5 by applying the second touch driving signal TXM to the fifth sensor electrode Y5, The touch input to the mutual capacitance sensor can be sensed through the fourth sensor electrode Y4. At this time, a base voltage (GND) or a direct-current voltage (DC) may be applied to the third sensor electrode Y3 to reduce the distortion of the sensing signal. Here, the sensor electrode to which the second touch driving signal TXM is applied becomes the Tx electrode, the capacitive sensor is formed adjacent to the Tx electrode, and the sensor electrode to be directly sensed becomes the Rx electrode. In this embodiment, the sensor electrodes for sensing the touch input to the mutual capacitance sensor are arranged as Rx-Tx-GND-Rx-Tx.

In this embodiment, the sensing unit 160 of FIG. 6, which is responsible for sensing the one-column sensor electrodes, is connected to the odd sensor electrodes Y1, Y3, ..., Y23 connected to the sensor wires of the sensor wires (AFE) for selectively sensing a touch input to the sensor electrodes (Y2, Y4, ..., Y22) connected to the sensor wirings, and a touch sensor (AFE). The multiplexer 140 of FIG. 6, which is responsible for sensing one row of sensor electrodes, selectively connects the first input terminal (-) of the radix sensing unit AFE to one of the radar sensor wirings, A rudder multiplexer MUXO for applying a second touch driving signal TXM to the other one of the wirings and a first input terminal (-) of the superior sensing unit AFE to selectively connect to one of the sensor wirings And a superior multiplexer (MUXE) for applying a second touch driving signal (TXM) to the other one of the sensor wires. Here, the radix sensing unit AFE and the superior sensing unit AFE operate simultaneously, and the radix multiplexer MUXO and the fine multiplexer MUXE operate simultaneously.

In the mutual sensing mode as shown in FIGS. 13 and 14, 26 * 23 (598) sensor electrodes are sensed through a total of 12 sensing operations. The second touch driving signal TXM is simultaneously applied to the sensor electrodes Y2 and Y5 at the first sensing time M1 and the sensor electrodes Y1 and Y4 are simultaneously sensed at the same time. The second touch driving signal TXM is simultaneously applied to the sensor electrodes Y3 and Y6 at the second sensing time M2 and the sensor electrodes Y2 and Y5 are simultaneously sensed at the same time. The second touch driving signal TXM is simultaneously applied to the sensor electrodes Y4 and Y7 at the third sensing time M3 and the sensor electrodes Y3 and Y6 are sensed at the same time in synchronization therewith. With this principle, twelve sensing operations are performed.

FIGS. 15 to 17 show another sensing channel selection procedure of the multiplexers in the mutual sensing mode, and the electrodes to be sensed according to the selection order.

Referring to FIG. 15, in the mutual sensing mode, the touch driving circuit 12 of the present invention can simultaneously sense the sensor electrodes in two rows apart from each other. In other words, the sensor electrodes include a first sensor electrode Y1, a second sensor electrode Y2 adjacent to the first sensor electrode Y1, a third sensor electrode Y3 adjacent to the second sensor electrode Y2, And the fourth sensor electrode Y4 adjacent to the third sensor electrode Y3 are arranged in the order of the first sensor electrode Y1 and the second sensor electrode Y2, the touch driving circuit 12 applies the second touch driving signal TXM to the second sensor electrode Y2 The touch input to the first mutual capacitance sensor formed between the first sensor electrode Y1 and the second sensor electrode Y2 is sensed through the first sensor electrode Y1 and the second touch sensing signal TXM is sensed through the first sensor electrode Y1. The touch input to the second mutual capacitance sensor formed between the third sensor electrode Y3 and the fourth sensor electrode Y4 by applying to the third sensor electrode Y3 can be sensed through the fourth sensor electrode Y4 have. Here, the sensor electrode to which the second touch driving signal TXM is applied becomes the Tx electrode, the capacitive sensor is formed adjacent to the Tx electrode, and the sensor electrode to be directly sensed becomes the Rx electrode. In this embodiment, the sensor electrodes for sensing the touch input to the mutual capacitance sensor are arranged as Rx-Tx-Tx-Rx. This electrode arrangement is advantageous in suppressing the voltage change between Tx and GDN and the charge loss due to the electric field formation as compared with that of Fig. In addition, in such an electrode arrangement, since the Tx electrodes are disposed adjacent to each other, the voltage change on the Tx electrode can be canceled, thereby maximizing the capacitance change of the mutual capacitance sensor.

In this embodiment, the sensing unit 160 of FIG. 6, which is responsible for sensing the one-column sensor electrodes, is connected to the odd sensor electrodes Y1, Y3, ..., Y23 connected to the sensor wires of the sensor wires (AFE) for selectively sensing a touch input to the sensor electrodes (Y2, Y4, ..., Y22) connected to the sensor wirings, and a touch sensor (AFE). The multiplexer 140 of FIG. 6, which is responsible for sensing one row of sensor electrodes, selectively connects the first input terminal (-) of the radix sensing unit AFE to one of the radar sensor wirings, A rudder multiplexer MUXO for applying a second touch driving signal TXM to the other one of the wirings and a first input terminal (-) of the superior sensing unit AFE to selectively connect to one of the sensor wirings And a superior multiplexer (MUXE) for applying a second touch driving signal (TXM) to the other one of the sensor wires. Here, the radix sensing unit AFE and the superior sensing unit AFE operate simultaneously, and the radix multiplexer MUXO and the fine multiplexer MUXE operate simultaneously.

In the mutual sensing mode as shown in FIGS. 16 and 17, 26 * 23 (598) sensor electrodes are sensed through a total of 12 sensing operations. The second touch driving signal TXM is simultaneously applied to the sensor electrodes Y2 and Y3 at the first sensing time M1 and the sensor electrodes Y1 and Y4 are simultaneously sensed at the same time. The second touch driving signal TXM is simultaneously applied to the sensor electrodes Y3 and Y4 during the second sensing period M2 and the sensor electrodes Y2 and Y5 are simultaneously sensed in synchronization with the second touch driving signal TXM. The second touch driving signal TXM is simultaneously applied to the sensor electrodes Y6 and Y7 at the third sensing time M3 and the sensor electrodes Y5 and Y8 are simultaneously sensed at the same time. With this principle, twelve sensing operations are performed.

FIG. 18 shows an example in which the capacitive sensors and the mutual capacitive sensors are alternately sensed in the touch interval. FIG. 19 shows an example in which the capacitive sensors and the mutual capacitive sensors are alternately sensed in the touch interval.

Referring to FIG. 18, the touch driving circuit 18 of the present invention alternately switches the self-sensing modes S1 to Sn and the mutual sensing modes M1 to Mn in the first period within the touch interval Tt, And the mutual capacitance sensors can be alternately sensed one by one. In the case of FIG. 18, since the self-sensing and the mutual sensing are continuously performed, it is advantageous to secure the continuity of the sensing data for each position. However, in the case of FIG. 18, since the switching time of the multiplexer for alternating the self-sensing and the mutual sensing is long, the sensing time may be long.

Referring to FIG. 19, the touch driving circuit 18 of the present invention alternates the self-sensing modes S1 to Sn and the mutual sensing modes M1 to Mn in a second period longer than the first period in the touch period Tt So that the magnetic capacitance sensors and the mutual capacitance sensors can be alternately sensed one by one. 19, the self-sensing is performed on all the sensor electrodes, and then the mutual sensing is performed on all the sensor electrodes. Therefore, the switching time of the multiplexer for alternating the self-sensing and the mutual sensing is small and the sensing time is short There are advantages. However, in the case of Fig. 19, this is disadvantageous compared with Fig. 18 in terms of securing the continuity of sensing data by position.

As described above, the touch sensing system of the present invention senses the touch input at each of the sensor electrodes using the capacitive sensors, senses the touch input among the sensor electrodes using mutual capacitance sensors, It is possible to improve the resolution, sensing sensitivity and accuracy of the touch screen without increasing the number of the touch screen.

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.

18: Touch driving circuit 140: Multiplexer
160: sensing unit 210: driving signal selection unit
220: Reference signal selector

Claims (9)

A touch screen including capacitive sensors provided on each of the sensor electrodes, mutual capacitance sensors provided between neighboring sensor electrodes, and sensor wires connected to the sensor electrodes;
Sensing a touch input to the capacitive sensors according to a first touch drive signal in a first sensing mode and a touch sensing a touch input to the capacitive sensors according to a second touch drive signal in a second sensing mode, And a driving circuit,
The touch-
A sensing unit for sensing the touch input;
A multiplexer for selectively connecting a first input terminal of the sensing unit to one of the sensor wirings;
The first touch driving signal is applied to the sensor wirings not connected to the sensing unit in the first sensing mode and the second touch driving signal is applied to the sensor wiring connected to the sensing unit in the second sensing mode A drive signal selection unit,
And a reference signal selection unit for applying the first touch driving signal to the second input terminal of the sensing unit in the first sensing mode and applying the reference voltage to the second input terminal of the sensing unit in the second sensing mode, . The method according to claim 1,
In the second sensing mode, the sensor wirings other than the first sensor wiring to which the second touch driving signal is applied and the second sensor wiring to be connected to the first input terminal of the sensing unit are subjected to touch sensing system. 3. The method of claim 2,
In the second sensing mode, a sensor electrode connected to the first sensor wiring and a sensor electrode connected to the second wiring are adjacent to each other. The method according to claim 1,
The sensing unit may include a radar sensing unit for selectively sensing a touch input to the radar sensor electrodes connected to the radar sensor wirings of the sensor wirings, And an excellent sensing unit for selectively sensing a touch input to the touch input,
The multiplexer includes a radar multiplexer for selectively connecting a first input end of the radar sensing unit to one of the radar sensor wirings and a radar sensor for selectively connecting the first input end of the superior sensor to any one of the sensor wirings Includes an excellent multiplexer,
Wherein the odd-numbered sensing unit and the superior-sensing unit are operated at the same time, and the odd-numbered multiplexer and the even-numbered multiplexer are simultaneously operated. 5. The method of claim 4,
The touch-
The method of claim 1, wherein in the first sensing mode, the first touch driving signal is applied to the first sensor electrode and the second sensor electrode which are adjacent to each other, and the touch input to the first capacitance sensor Sensing the touch input through the first sensor electrode and the touch input to the second capacitive sensor provided on the second sensor electrode through the second sensor electrode. 5. The method of claim 4,
Wherein the sensor electrodes include a first sensor electrode, a second sensor electrode adjacent to the first sensor electrode, a third sensor electrode adjacent to the second sensor electrode, a fourth sensor electrode adjacent to the third sensor electrode, And the fifth sensor electrode adjacent to the fourth sensor electrode,
The touch-
In the second sensing mode, the second touch driving signal is applied to the second sensor electrode, and the touch input to the first inter-capacitive sensor provided between the first sensor electrode and the second sensor electrode is applied to the first sensor electrode Sensing the touch input to the second inter-capacitive sensor provided between the fourth sensor electrode and the fifth sensor electrode by applying the second touch driving signal to the fifth sensor electrode, Sensing through the sensor electrode,
And a base voltage or a DC voltage is applied to the third sensor electrode. 5. The method of claim 4,
The sensor electrodes are arranged in the order of a first sensor electrode, a second sensor electrode adjacent to the first sensor electrode, a third sensor electrode adjacent to the second sensor electrode, and a fourth sensor electrode adjacent to the third sensor electrode When deployed,
The touch-
In the second sensing mode, the second touch driving signal is applied to the second sensor electrode, and the touch input to the first inter-capacitive sensor provided between the first sensor electrode and the second sensor electrode is applied to the first sensor electrode Sensing the touch input to the second mutual capacitance sensor provided between the third sensor electrode and the fourth sensor electrode by applying the second touch driving signal to the third sensor electrode, A touch sensing system for sensing through a sensor electrode. The method according to claim 1,
The touch-
Wherein the first sensing mode and the second sensing mode alternately sense the capacitive sensors and the mutual capacitance sensors partly. The method according to claim 1,
The touch-
Wherein the first sensing mode and the second sensing mode alternately sense the capacitive sensors and the mutual capacitive sensors all at once.

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