KR20170081128A - Active stylus pen and touch sensing system and driving method of the same - Google Patents

Abstract

The active stylus pen of the present invention includes a first signal processing unit for generating a touch frame recognition signal based on sub pulses corresponding to a part of each touch screen driving signal received from a touch screen, And a second signal processor for generating a pen drive signal so as to be synchronized with the main pulse except that the pen additional information is reflected on the pen drive signal in units of touch frames in accordance with the touch frame recognition signal .

Description

TECHNICAL FIELD [0001] The present invention relates to an active stylus pen, a touch sensing system including the active stylus pen,

The present invention relates to a touch sensing system, and more particularly, to a touch sensing system capable of touch input through an active stylus pen and a driving method thereof.

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. When a finger or a conductive material touches (or comes close to) the touch sensor, the touch screen having the capacitive touch sensor senses a change in capacitance due to the input of the touch screen drive signal, that is, Thereby detecting the touch input.

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. The mutual capacitance sensor may be formed at the intersection of the sensor wirings orthogonal to each other with the dielectric layer interposed therebetween.

In recent years, not only a finger but also a stylus pen have been widely used as a human interface device (HID) in smart phones and smart books. The stylus pen has the advantage of being able to input more finely than the finger. There are passive and active stylus pens. In the passive type, it is difficult to detect the touch position because the capacitance change is small at the contact point with the touch screen. The active type generates the pen drive signal itself and outputs it to the contact point with the touch screen, so it is easier to detect the touch position than the passive type.

Recently, an active stylus pen is designed not only to transmit a pen drive signal but also to transmit various pen additional information such as pressure information, button state information, pen identification (ID) information, and the like. However, as disclosed in Korean Patent Publication No. 10-2014-0043299, the conventional active stylus pen requires a separate communication block to transmit the pen additional information to the touch module, which increases the manufacturing cost . Moreover, the conventional active stylus pen transmits the pen driving signal and the pen additional information individually, which causes a large transmission load. In order to solve this problem, it is possible to consider transmitting pen-side information to the pen drive signal and transmitting the pen-side information on a touch frame basis. However, this requires that the active stylus pen be able to distinguish the touch frame, which has not yet been developed.

Accordingly, it is an object of the present invention to provide an active stylus pen capable of easily distinguishing a touch frame from an active stylus pen, reflecting the pen additional information on a pen drive signal in units of one touch frame, a touch sensing system including the active stylus pen, Method.

It is another object of the present invention to provide an active stylus pen, a touch sensing system including the active stylus pen, and a method of driving the same, which can improve the accuracy of synchronization between the active stylus pen and the touch screen.

In order to achieve the above object, an active stylus pen of the present invention includes a first signal generating a touch frame recognition signal for distinguishing a touch frame based on sub pulses corresponding to a part of each touch screen driving signal received from a touch screen, A pen drive signal generating unit for generating a pen drive signal in synchronization with the main pulse except for the sub pulse in each of the touch screen drive signals and generating the pen drive signal in accordance with the touch frame recognition signal so that the pen additional information is reflected in the pen drive signal And a second signal processing unit which varies in touch frame units.

The first signal processor counts the first sub pulse of one touch screen drive signal and the second sub pulse of another touch screen drive signal neighboring the one touch screen drive signal to generate a first count value And generates the touch frame recognition signal when the first count value exceeds a preset threshold value.

The first signal processing unit generates a second count value by counting the sub pulses contained in each touch screen driving signal and generates the touch frame recognition signal when the second count value satisfies a preset value .

And the second signal processing unit varies the pulse amplitude of the pen drive signal in units of touch frames according to the touch frame recognition signal so that the pen additional information is reflected in the pen drive signal.

The second signal processing unit varies the pulse duty of the pen drive signal in units of touch frames according to the touch frame recognition signal so that the pen additional information is reflected in the pen drive signal.

And the second signal processing unit assigns one bit of the pen drive signal reflecting the pen additional information to one touch frame.

Wherein the pen additional information includes at least one of a pressure information indicating pressure when the active stylus pen contacts the touch screen, a button state indicating whether the at least one functional button provided in the active stylus pen performs a specific function, Information, and pen identification information to distinguish it from other active stylus pens.

According to another aspect of the present invention, there is provided a touch sensing system including a touch screen, a touch driving device for applying a touch screen driving signal to the touch screen and sensing a capacitance change of the touch screen, Wherein the active stylus pen includes a first signal for generating a touch frame recognition signal for distinguishing a touch frame based on sub pulses corresponding to a part of each touch screen driving signal received from the touch screen, And a controller for generating the pen driving signal so that the pen driving signal is synchronized with the main pulse except for the sub pulse in each touch screen driving signal, A second signal processing unit for varying in units of touch frames .

According to another aspect of the present invention, there is provided a method of driving a touch sensing system including the steps of: receiving an active stylus pen from a touch screen; receiving a touch screen driving signal from the active stylus pen; Generating a pen drive signal from the stylus pen and outputting the generated pen drive signal to the touch screen; sensing a capacitance change of the touch screen according to the touch screen drive signal and the pen drive signal in a touch drive device connected to the touch screen Generating the pen drive signal from the active stylus pen and outputting the generated pen drive signal to the touch screen includes generating a pen drive signal based on a sub pulse corresponding to a part of each touch screen drive signal received from the touch screen, A touch frame recognition signal And generating the pen driving signal so as to be synchronized with the main pulse except for the sub pulse in each of the touch screen driving signals so that the pen additional information is reflected in the pen driving signal, And varying the driving signal in units of touch frames.

The present invention generates a touch frame recognition signal based on a sub pulse corresponding to a part of each touch screen driving signal received from a touch screen, and generates a touch frame recognition signal based on a pulse amplitude and / or a pulse duty of the pen driving signal The pen additional information can be effectively reflected in the pen drive signal by a method of adjusting the touch frame recognition signal in units of one touch frame. According to the present invention, by sensing a change in size of data by a touch according to a pen drive signal, the pen additional information reflected in the pen drive signal can be obtained.

The present invention drives a patterned synchronization signal on a touch screen to increase the accuracy of synchronization between the active stylus pen and the touch screen. In addition, the present invention can implement various additional functions by transmitting a command from a touch screen to a pen using a bit-assigned synchronization signal.

BRIEF DESCRIPTION OF THE DRAWINGS Figure 1 is a schematic illustration of a touch sensing system of the present invention.
2 is a view illustrating a display device to which a touch sensing system according to an embodiment of the present invention is applied.
3 is a view showing an example of a touch sensor built 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.
FIG. 5 illustrates an example in which a plurality of touch frames are included in one display frame period. FIG.
6 to 8 are views showing a touch driving apparatus according to an embodiment of the present invention.
9 is a view showing the multiplexers and sensing units connected to the touch sensor blocks;
10 is a view showing an internal configuration of an active stylus pen according to the present invention.
11 is a flowchart showing an operation procedure for reflecting pen-side information in an active stylus pen according to the present invention to a pen driving signal.
FIGS. 12A and 12B are diagrams showing various schemes of dividing a touch frame in an active stylus pen and various modulation patterns of a pen driving signal for expressing pen additional information. FIG.
13A and 13B are views showing various ways of distinguishing a touch frame in an active stylus pen and various modulation patterns of a pen driving signal for expressing pen additional information.
14 is a view showing an example of generating pen additional information by utilizing a plurality of touch frames in an active stylus pen;
15 is a diagram showing a change in touch raw data sensed by a touch driving device according to pen additional information;
Figures 16 and 17 are diagrams illustrating ways to increase the accuracy of synchronization between the active stylus pen and the touch screen.
18 is a diagram showing an example of bit allocation according to a pattern of a synchronization signal;

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.

[Touch Sensing  system]

1 schematically shows a touch sensing system of the present invention.

Referring to FIG. 1, the touch sensing system of the present invention includes a display device 10 and an active stylus pen 20.

The display device 10 performs a display function and a touch detection function. The display device 10 is capable of touch detection by the contact of a finger or a conductive object such as the active stylus pen 20, and is equipped with an electrostatic capacitive type touch screen integrally therewith. Here, the touch screen may be configured independently of the display panel for implementing the display, or may be embedded in the pixel array of the display panel. The specific configuration and operation of the display apparatus 10 will be described later with reference to Figs. 2 to 9. Fig.

The active stylus pen 20 generates a pen driving signal on the basis of a touch screen driving signal received from the touch screen, and outputs the pen driving signal to a point of contact with the touch screen, thereby facilitating the touch position detection on the touch screen. The active stylus pen 20 generates a touch frame recognition signal based on sub pulses corresponding to a part of each touch screen driving signal and outputs pen driving signals in accordance with a touch frame recognition signal so that preset pen- The signal is varied in touch frame units. The touch sensing system analyzes the change of the touch raw data with a touch according to the pen driving signal and senses the touch input position and the touch side information by the active stylus pen 20. The pen additional information includes the pressure information indicating the pressure when the active stylus pen contacts the touch screen, the button status information indicating whether the at least one functional button performing the specific function is provided in the active stylus pen, And pen identification information for distinguishing the active stylus pen from the active stylus pen.

The construction and operation of the active stylus pen 20 will be described later with reference to FIGS. 10 to 15. FIG.

[Display device]

FIG. 2 shows a display device 10 to which a touch sensing system according to an embodiment of the present invention is applied. FIG. 3 shows an example of a touch sensor built in a pixel array. FIG. 4 shows a method of time-divisionally driving the pixels and the touch sensors of the display panel as shown in FIG. FIG. 5 shows an example in which a plurality of touch frames are included in one display frame period. 6 to 8 show a touch driving apparatus according to an embodiment of the present invention. Figure 9 shows the multiplexers and sensing units connected to the touch sensor blocks.

2 to 9, the display device 10 of the present invention includes a liquid crystal display (LCD), a field emission display (FED), a plasma display panel (PDP) ), An organic light emitting diode (OLED) display, and an electrophoresis (EPD) display device. 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 10 comprises a display module and a touch module.

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

The touch screen (TSP) can be implemented in a capacitive manner that senses touch input through a plurality of capacitive sensors. The touch screen TSP includes a plurality of touch sensors having a capacitance. Capacitance can be divided into Self Capacitance and Mutual Capacitance. The electrostatic capacitance can be formed along a single-layer conductor wiring formed in one direction, and mutual capacitance can be formed between two orthogonal conductor wiring.

The touch sensors of the touch screen (TSP) may be embedded 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. Referring to 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, where i is smaller than m, n 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, as shown in FIG. 4, the touch sensors C1 to C4 supply the common voltage Vcom to the pixels 101 during the display periods Td1 and Td2, and during the touch periods Tt1 and Tt2, (Ts) and senses the touch input. 3 shows the self-capacitance type touch sensor, the touch sensors C1 to C4 are not limited thereto.

The touch driving device 18 applies the touch screen driving signal Ts to the touch sensors C1 to C4 and senses the amount of charge change of the touch sensors C1 to C4 to detect Determine whether or not the conductive material is touched and its position.

The touch driving device 18 drives the touch sensors 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 device 18 supplies the touch screen driving signal Ts to the touch sensors C1 to C4 through the sensor lines L1 to Li during the touch periods Tt1 and Tt2 to sense the touch input. The touch driver 18 analyzes the charge variation of the touch sensor depending on the presence or absence of the touch input, determines 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.

The touch driving device 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 TF1, TF2 and TF3 for driving the touch sensors C1 to C4 can be allocated to at least two or more touch frames 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 driver 18 sequentially outputs the touch interval Tt1 And Tt2, and transmits coordinate information of the touch input to the host system 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.

The touch-driving device 18 of the present invention can be implemented as an IC (Integrate Circuit) package as shown in Figs.

Referring to FIG. 6, the touch driver 18 includes a driver IC (DIC) and a touch IC (TIC).

The driver IC DIC includes a touch sensor channel unit 100, a Vcom buffer 110, a switch array 120, a timing control signal generating unit 130, a multiplexer (MUX) 140, 150).

The touch sensor channel unit 100 is connected to the electrodes of the touch sensors through the sensor lines and is connected to the Vcom buffer 110 and the multiplexer 140 through the switch array 120. The multiplexer 140 couples the sensor lines to the touch IC (TIC). In the case of the 1: 3 multiplexer, the multiplexer 140 reduces the number of channels of the touch IC (TIC) by sequentially connecting one channel of the touch IC (TIC) to the three sensor lines in a time division manner. The multiplexer 140 sequentially selects the sensor 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 140 is connected to the channels of the touch IC (TIC) through the touch lines.

The Vcom buffer 110 outputs the common voltage Vcom of the pixel. The switch array 120 supplies the common voltage Vcom from the Vcom buffer 110 to the touch sensor channel unit 100 under the control of the timing control signal generator 130 during the display period. The switch array 120 connects the sensor lines to the touch IC (TIC) under the control of the timing control signal generator 130 during the touch interval.

The timing control signal generator 130 generates timing control signals for controlling operation timings of the display driver circuit and the touch IC (TIC).

The timing control signal generator 130 may be included in the timing controller 16 shown in FIG. The timing control signal generator 130 drives the display driving circuit during the display period and drives the touch IC (TIC) during the touch interval.

The timing control signal generating unit 130 generates a touch enable signal TEN defining the display periods Td1 and Td2 and the touch periods Tt1 and Tt2 as shown in FIG. . The display driving circuit writes the image data to the pixels during the first level period of the touch enable signal TEN. The touch IC (TIC) senses the touch input by driving the touch sensors in response to the second level of the touch enable signal TEN. The first level of the touch enable signal TEN may be a high level, the second level may be a low level, and vice versa.

The touch IC (TIC) is connected to a driving power source (not shown) to receive driving power. The touch IC TIC generates a touch screen driving signal Ts in response to a second level of the touch enable signal TEN and applies the touch screen driving signal Ts to the touch sensors. The touch screen driving signal Ts 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 screen driving signal Ts may be applied to each of the touch sensors N times so that electric charge can be accumulated in the integrator of the touch IC (TIC) N or more times (N is a natural number of 2 or more).

The noise may be increased in the touch sensor signal according to the change of the input image data. The DTX compensator 150 analyzes the input image data, removes noise components from the touch raw data according to the gradation change of the input image, and transmits the same to the touch IC (TIC). DTX stands for Display and Touch crosstalk. The contents of the DTX compensation unit 150 are described in detail in the patent application No. 10-2012-0149028 (filed December 19, 2012), which is filed by the present applicant. In the case of a system in which the noise of the touch sensor does not change sensitively according to the data change of the input image, the DTX compensation unit 150 is not necessary and can be omitted. In FIG. 6, DTX DATA is output data of the DTX compensation unit 150.

The touch IC TIC drives the multiplexer 140 during the touch periods Tt1 and Tt2 in response to the touch enable signal TEN from the timing control signal generation unit 130 so that the touch IC And receives the charge of the touch sensor. In FIG. 6, MUXs C1 to C3 are signals for selecting the channel of the multiplexer.

The touch IC (TIC) detects the amount of charge change before and after the touch input from the touch sensor signal, compares the amount of charge change with a predetermined threshold value, and determines the position of the touch sensor having the charge variation amount equal to or larger than the threshold value as the touch input area. The touch IC (TIC) calculates coordinates for each of the touch inputs and transmits touch data (TDATA (XY)) including the touch input coordinate information to the external host system 19. 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 (Analog to Digital Converter) for converting the voltage of the integrator into digital data, and an arithmetic logic section. The arithmetic logic unit compares the touch raw data output from the ADC with a threshold value, and executes a touch recognition algorithm that determines a touch input and calculates coordinates based on the comparison result.

The driver IC (DIC) and the touch IC (TIC) can transmit and receive signals through the SPI (Serial Peripheral Interface) interface.

The host system 19 refers to a system body of an electronic apparatus to which the display apparatus 10 of the present invention is applicable. The host system 19 may be any one of a phone system, a television system, a set top box, a navigation system, a DVD player, a Blu-ray player, a personal computer (PC), and a home theater system. The host system 19 transmits the input image data RGB to the driver IC DIC and receives the touch input data TDATA XY from the touch IC TIC and outputs an application associated with the touch input, .

Referring to FIG. 7, the touch driver 18 includes a driver IC (DIC) and a micro controller unit (MCU).

The driver IC DIC includes a touch sensor channel unit 100, a Vcom buffer 110, a switch array 120, a first timing control signal generating unit 130, a multiplexer 140, a DTX compensating unit 150, Unit 160, a second timing control signal generator 170, and a memory 180. This embodiment differs from the embodiment of FIG. 6 in that the sensing unit 160 and the second timing control generator 170 are integrated in the driver IC (DIC). The first timing control generator 130 is substantially the same as that of FIG. Accordingly, the first timing control generator 130 generates timing control signals for controlling the operation timing of the display driver circuit and the touch IC (TIC).

The multiplexer 140 floats the touch sensor electrodes that are accessed by the sensing unit 160 under the control of the MCU. The sensing unit 160 accesses other touch sensor electrodes except the touch sensor electrodes connected to the pixels for charging the data voltage. The multiplexer 140 can supply the common voltage Vcom under the control of the MCU. When the resolution of the touch screen is M × N (M and N are positive integers of 2 or more) as shown in FIG. 9, the number of required multiplexers 140 is M. When the resolution of the touch screen is M x N, the touch sensor electrodes 22 are divided into M x N pieces. Each of the multiplexers 140 is connected to N touch sensor electrodes 22 through N sensor lines 115 and sequentially connects N sensor lines 115 to one sensing unit 160 .

The sensing unit 160 is connected to the sensor lines 115 via the multiplexer 140 to measure a change in the voltage waveform received from the touch sensor electrodes 22 and convert the measurement result into digital data. The sensing unit 160 includes an amplifier for amplifying the voltage of the touch sensor electrodes 22, an integrator for accumulating the voltage of the amplifier, an analog-to-digital converter (ADC) for converting the voltage of the integrator into digital data , Hereinafter referred to as "ADC"). 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 × N (M and N are positive integers of 2 or more) as shown in FIG. 9, M number of sensing units 160 are required.

The second timing control generator 170 generates a timing control signal for controlling the operation timing of the multiplexer 140, the sensing unit 160, a clock, and the like. The DTX compensation section 150 in the driver IC (DIC) may be omitted. The memory 180 temporarily stores data (TDATA) under the control of the second timing control generator 170.

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

Referring to FIG. 8, the touch driver 18 includes a driver IC (DIC) and a memory (MEM).

The driver IC DIC includes a touch sensor channel unit 100, a Vcom buffer 110, a switch array 120, a first timing control signal generating unit 130, a multiplexer 140, a DTX compensating unit 150, Unit 160, a second timing control signal generator 170, a memory 180, and an MCU 190. This embodiment differs from the above-described embodiment of FIG. 6 in that the MCU 190 is integrated in a driver IC (DIC). The MCU 18 compares the data TDATA with a threshold value by touching, executes a touch recognition algorithm for determining a touch input according to the comparison result, and calculating coordinates.

The memory MEM stores a register setting value related to the timing information required for the operation of the display driving circuit and the sensing unit 160. [ The register set value is loaded from the memory MEM to the first timing control signal generator 16 and the second timing control signal generator 170 when the power of the display device is turned on. The first timing control signal generator 16 and the second timing control signal generator 170 generate timing control signals for controlling the display driving circuit and the sensing unit 160 based on the register set values read from the memory do. 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.

The display module may include a display panel (DIS), a display driving 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 gate drive circuit 14 may be disposed together with the pixels on the substrate of the display panel DIS.

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 to the timing controller 16 together with the digital video data RGB and outputs the touch coordinate information XY ). ≪ / RTI >

On the other hand, the touch enable signal TEN of FIG. 4 may be generated in the host system 19. During the display periods Td1 and Td2, the data driving circuit 12 supplies the data voltages to the data lines D1 to Dm under the control of the timing controller 16, and the gate driving circuit 14 supplies the data voltages to the timing controller 16 Sequentially supplies gate pulses synchronized with the data voltage to the gate lines G1 to Gn. Meanwhile, during the display periods Td1 and Td2, the touch-driving device 18 stops operating.

During the touch periods Tt1 and Tt2, the touch driving device 18 applies a touch screen driving signal Ts to the touch sensors of the touch screen TSP. During the touch periods Tt1 and Tt2, the display driver circuits 12, 14, and 16 are turned on and off in order to minimize the parasitic capacitance between the signal lines D1 to Dm and G1 to Gn connected to the pixels and the touch sensors It is possible to supply an AC signal having the same amplitude and the same phase as the touch screen driving signal Ts to the signal lines D1 to Dm and G1 to Gn. In this case, the display noise mixed into the touch sensing signal is remarkably reduced, and the accuracy of the touch sensing is increased.

 [ Stylus  pen]

10 shows the internal structure of the active stylus pen 20 according to the present invention.

10, the active stylus pen 20 includes a housing 280, a conductive tip 210 protruding from one side of the housing 280, and a conductive tip 210 connected to the conductive tip 210 inside the housing 280 A switching unit 220 and a switching unit 220. The switching unit 220 includes a receiving unit 230 for receiving a touch screen driving signal input from the conductive tip 210, A signal processing unit 250 for generating a digital pen driving signal in which the information is reflected, a level shifter for shifting the digital pen driving signal generated in the signal processing unit 250 to an analog level, A power supply unit 260 for generating a driving power required for the operation, and an input / output interface 270. The power supply unit 260 includes a power supply unit 240,

The conductive tip 210 is made of a conductive material such as metal and serves as a receiving electrode and a transmitting electrode. When the conductive tip 210 contacts the touch screen TSP of the display device 10, the conductive tip 210 at that point of contact is coupled to the touch screen TSP. The conductive tip 210 receives the touch screen drive signal from the touch screen TSP at the touch point and then transmits the pen drive signal generated inside the active stylus pen 20 to the touch screen TSP Point.

The switching unit 220 electrically connects the conductive tip 210 and the receiving unit 230 for Rx time when the conductive tip 210 is in contact with the touch screen TSP of the display apparatus 10 The conductive tip 210 and the driving unit 240 are electrically connected to each other for a period of Tx, thereby temporally separating the reception timing of the touch screen driving signal and the transmission timing of the pen driving signal. Since the conductive tip 210 also serves as a receiving electrode and a transmitting electrode, the structure of the active stylus pen 20 is simplified.

The receiving unit 230 may include at least one amplifier to amplify a touch screen driving signal input from the conductive tip 210 through the switching unit 220. The receiving unit 230 includes a comparator, compares the amplified signal with a preset reference voltage, and outputs the result to the signal processing unit 250.

The signal processing unit 250 divides the touch frame based on the touch screen driving signal input from the receiving unit 230, and varies the pen driving signal on a touch frame basis to reflect the pen additional information on the pen driving signal. To this end, the signal processing unit 250 includes a first signal processing unit for identifying the touch frame and a second signal processing unit for reflecting the pen additional information on the pen driving signal.

The first signal processing unit may generate a touch frame recognition signal based on sub pulses corresponding to a part of each touch screen driving signal received from the touch screen. The second signal processing unit generates a pen driving signal so that the pen additional information is reflected in the pen driving signal so that the pen driving signal is synchronized with the main pulse except for the sub pulse in each touch screen driving signal, .

The signal processing unit 250 outputs a pen driving signal reflecting the pen additional information to the driving unit.

The driver 240 includes a level shifter to shift a pen drive signal at a digital level to an analog level. The driving unit 240 outputs the level-shifted pen driving signal to the conductive tip 210 through the switching unit 220.

The input / output interface 270 is connected to the power supply unit 260 and can supply necessary power to the receiving unit 230, the driving unit 240, and the signal processing unit 250.

11 shows an operation procedure for reflecting the pen additional information in the pen drive signal in the active stylus pen 20 according to the present invention.

11, the conductive tip 210 contacts a predetermined point of the touch screen TSP (S1, S2) while the power is applied through the input / output interface 270 and the power supply unit 260. FIG.

During the touch interval, each touch sensor of the touch screen (TSP) is supplied with a touch screen drive signal. During the touch interval, the conductive tip 210 is coupled to the touch screen TSP at the contact point to sense the touch screen drive signal received from the touch screen TSP and deliver the sensed signal to the receiver 220 . The receiving unit 220 amplifies the touch screen driving signal through an internal amplifier, compares the amplified signal with a reference voltage in an internal comparator, and outputs the comparison result to the signal processing unit 250 (S3).

The signal processing unit 250 analyzes a touch screen driving signal inputted from the receiving unit 230 to determine a timing to be synchronized with the touch screen driving signal, and generates a pen driving signal according to the synchronizing timing. In particular, the signal processing unit 250 generates a touch frame recognition signal based on the touch screen driving signal to distinguish the touch frame, and generates the pulse amplitude and / or pulse width of the pen driving signal in units of touch frames, By varying the duty, the pen drive signal reflecting the pen additional information is outputted (S4, S5, S6).

12A and 12B show various ways of distinguishing a touch frame from an active stylus pen and various modulation patterns of a pen driving signal for expressing pen additional information. 13A and 13B show other ways of distinguishing the touch frame in the active stylus pen and various modulation types of the pen driving signal for expressing pen additional information. 14 shows a method of generating pen additional information by utilizing a plurality of touch frames in an active stylus pen. 15 shows the change of the touch raw data sensed by the touch driving device according to the pen additional information.

12A and 12B, the first signal processing unit of the active stylus pen 20 includes a first sub pulse of one touch screen driving signal Ts and another touch signal of a touch adjacent to the one touch screen driving signal Ts Generates a first count value by counting the second sub pulse interval of the screen driving signal Ts and outputs a touch frame recognition signal TFsync for discriminating a touch frame when the first count value exceeds a predetermined threshold value Can be generated. 12A and 12B, Mux 1 to Mux last are touch screen driving signals corresponding to one touch period (Tt1 or Tt2) shown in FIG.

The touch screen driving signal Ts includes a sub pulse assigned to a partial interval of one touch interval and a main pulse allocated to the remaining interval of one touch interval. The sub pulse of the touch screen driving signal Ts can be used to judge the validity of the touch screen driving signal Ts. The first signal processing unit of the active stylus pen 20 can generate the touch frame recognition signal TFsync based on the sub pulse of the touch screen driving signal Ts.

For example, the first signal processing unit may include a first signal processing unit for generating a plurality of touch screen driving signals (intervals Mux 1 and Mux 2, Mux 2 and Mux 3, ..., Mux Last-1 and Mux Last, Mux Last and Mux 1) (D or D + d), and generates a touch frame recognition signal (TFsync) when the first count value exceeds a preset threshold value. When the vertical blank period d is further included between the touch frames TFn-1 and TFn, the interval (D + 1) between the touch screen driving signals Mux Last and Mux 1 adjacent to each other in the different touch frames, d may be larger than the interval D between the touch screen driving signals Mux Last-1 and Mux Last adjacent to each other within the same touch frame by the vertical blank period d. In this case, the first signal processing unit determines that the touch screen driving signal (Mux 1) following the touch screen driving signal (Mux Last) belongs to a new touch frame, and the touch screen driving signal The frame recognition signal TFsync can be generated.

12A and 12B, the second signal processing unit of the active stylus pen 20 generates the pen driving signal Ps so as to be synchronized with the main pulse except for the sub pulse in each touch screen driving signal Ts. The second signal processing unit of the active stylus pen 20 generates a pulse of the pen driving signal Ps in accordance with the touch frame recognition signal TFsync so that the preset pen- The pen drive signal Ps (Ps) is changed in accordance with the touch frame recognition signal TFsync so that the duty can be changed in units of the touch frames TFn-1 and TFn or the pen additional information set in advance as shown in Fig. 12B is reflected in the pen drive signal Ps ) Can be varied in increments of the touch frame (TFn-1, TFn). The second signal processing unit of the active stylus pen 20 receives the pen drive signal Ps (Ps) in accordance with the touch frame recognition signal TFsync so that the preset pen additional information is reflected in the pen drive signal Ps ) May be varied in increments of the touch frame (TFn-1, TFn).

13A and 13B, the first signal processing unit of the active stylus pen 20 counts sub pulses contained in each touch screen driving signal Ts to generate a second count value, and the second count value The touch frame recognition signal TFsync for distinguishing the touch frame can be generated when the preset value is satisfied. 13A and 13B, Mux 1 to Mux last are touch screen driving signals corresponding to one touch period (Tt1 or Tt2) shown in FIG. For example, when the two count values corresponding to the number of sub pulses # 1 to # Last contained in each touch screen driving signal Ts satisfy a preset value, The frame recognition signal TFsync can be generated.

13A and 13B, the second signal processing unit of the active stylus pen 20 generates the pen driving signal Ps so as to be synchronized with the main pulse except for the sub pulse in each touch screen driving signal Ts. At this time, the second signal processing unit of the active stylus pen 20 generates a pulse of the pen driving signal Ps in accordance with the touch frame recognition signal TFsync so that the preset pen additional information is reflected in the pen driving signal Ps The pen drive signal Ps (Ps) is generated in accordance with the touch frame recognition signal TFsync so that the duty can be changed in units of the touch frames TFn-1 and TFn or the pen additional information set in advance as shown in Fig. ) Can be varied in increments of the touch frame (TFn-1, TFn). The second signal processing unit of the active stylus pen 20 receives the pen drive signal Ps (Ps) in accordance with the touch frame recognition signal TFsync so that the preset pen additional information is reflected in the pen drive signal Ps ) May be varied in increments of the touch frame (TFn-1, TFn).

On the other hand, the touch input detection should not be disturbed due to the variation of the pen drive signal Ps. Therefore, the range in which the pulse amplitude and / or the pulse duty of the pen drive signal Ps can be varied in order to indicate the pen additional information in the second signal processing section should be within a range in which the pen drive signal (Ps) touch input detection is possible .

On the other hand, the second signal processing section generates the pen drive signal Ps corresponding to each touch frame by generating the pen drive signal Ps in which the pen additional information is reflected in the same manner as in Figs. 12A to 13B, "Can be expressed as. That is, the second signal processing section can generate the pen drive signal Ps to have the first pulse amplitude and / or the first pulse duty so as to express the pen drive signal Ps as "1 & (Smaller than the first pulse amplitude) and / or the second pulse duty (smaller than the first pulse duty) in order to represent the pen drive signal Ps as "0" .

The second signal processing unit can implement sophisticated information representation by implementing the pen drive signal Ps reflecting the pen additional information in one touch frame by one bit in a plurality of touch frames. For example, as shown in FIG. 14, the second signal processing unit can display 256 steps by assigning 1 bit to the eight touch frames TF1 to TF8, respectively, of the pen drive signal Ps in which the pen additional information is reflected.

The touch sensing value (data by touch) according to the pen driving signal Ps represented by the logical value "1 " is larger than the touch sensing value according to the pen driving signal Ps represented by the logical value" 0 " . The touch driving device 18 of the display device 10 can detect the pen additional information of a plurality of bits based on the magnitude of the touch sensing value in accordance with the pen driving signal Ps.

Figures 16 and 17 illustrate how to increase the accuracy of synchronization between the active stylus pen and the touch screen. FIG. 18 shows an example of bit allocation according to a pattern of a synchronization signal.

The active stylus pen operates by way of driving a signal synchronized with the touch screen. Therefore, there is a need for a method that allows the active stylus pen to accurately synchronize even in environments with varying noises. In addition, it is necessary to implement the function of changing the operating frequency of the active stylus pen and other additional functions to avoid performance degradation due to noise.

16 and 17, the touch screen driving signal Ts of the present invention may be a beacon signal including a pen operation mode, a hovering or contact state, a tilt data transmission state, Signal. The beacon signal corresponds to the dummy touch interval (Dummy TP). The active stylus pen generates a touch frame recognition signal TFsync based on a beacon signal and can distinguish a touch frame according to a touch frame recognition signal TFsync.

The sub pulse of the touch screen drive signal Ts and the beacon signal are synchronization signals for synchronization between the main pulse of the touch screen drive signal Ts and the pen drive signal Ps. The touch driver drives a beacon signal in a dummy TP section and drives a patterned ping signal in each touch section TP so that accurate synchronization can be obtained even when noise is present. The synchronization signal can be implemented with patterned Direct Sequence Spread Spectrum (DSSS) code to maximize noise immunity. If the synchronization signal is implemented in the DSSS code, the signal bandwidth can be dispersed and transmitted, thereby improving the signal-to-noise ratio (SNR). In other words, if the synchronization signal is implemented in the DSSS code, it can be driven in a noisy environment, thereby increasing the accuracy of synchronization between the active stylus pen and the touch screen.

The touch driver may transmit a command from the touch screen to the active stylus pen, and may transmit a variety of additional functions by allocating a plurality of bits according to the pattern of the synchronization signal. That is, the touch driving apparatus can drive a beacon signal bit-allocated as shown in FIG. 18 in a dummy touch interval (Dummy TP) to transmit various additional functions such as changing a driving frequency of a pen, changing operation parameters, and the like to the pen. In addition, the touch driving apparatus can drive a bit-assigned ping signal as shown in FIG. 18 in each touch period TP to increase the accuracy of synchronization between the active stylus pen and the touch screen. As described above, Generates a touch frame recognition signal based on sub pulses corresponding to a part of each touch screen driving signal received from the touch screen, and outputs the pulse amplitude and / or pulse duty of the pen driving signal to the touch frame It is possible to effectively reflect the pen additional information to the pen drive signal by a method of adjusting in units of one touch frame in accordance with the recognition signal. According to the present invention, by sensing a change in size of data by a touch according to a pen drive signal, the pen additional information reflected in the pen drive signal can be obtained.

Furthermore, the present invention can increase the accuracy of synchronization between the active stylus pen and the touch screen using a patterned synchronization signal. In addition, the present invention can implement various additional functions by transmitting a command from a touch screen to a pen using a bit-assigned synchronization signal.

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.

10: display device 18: touch drive device
20: Stylus Pen 210: Conductive tip
220: switching unit 230: receiving unit
240: driver 250: signal processor

Claims (33)

A first signal processing unit for generating a touch frame recognition signal for identifying a touch frame based on sub pulses corresponding to a part of each touch screen driving signal received from the touch screen; And
Generating a pen driving signal so as to be synchronized with the main pulse except for the sub pulse in each of the touch screen driving signals so that the pen additional information is reflected in the pen driving signal, And a second signal processing unit that varies the first signal processing unit. The method according to claim 1,
Wherein the first signal processor comprises:
A first count value is generated by counting a first sub pulse of one touch screen driving signal and a second sub pulse of another touch screen driving signal neighboring the one touch screen driving signal, And generates the touch frame recognition signal when a preset threshold value is exceeded. The method according to claim 1,
Wherein the first signal processor comprises:
Generating a second count value by counting the sub pulses included in each touch screen drive signal and generating the touch frame recognition signal when the second count value satisfies a predetermined value. The method according to claim 1,
Wherein the second signal processing unit comprises:
Wherein the pulse amplitude of the pen drive signal varies in units of touch frames in accordance with the touch frame recognition signal so that the pen additional information is reflected in the pen drive signal. The method according to claim 1,
Wherein the second signal processing unit comprises:
Wherein the pulse duty of the pen driving signal varies in units of touch frames in accordance with the touch frame recognition signal so that the pen additional information is reflected in the pen driving signal. 6. The method according to any one of claims 1 to 5,
Wherein the second signal processing unit comprises:
And a pen drive signal in which the pen additional information is reflected is allocated to each touch frame by one bit. The method according to claim 1,
Wherein the pen additional information includes at least one of a pressure information indicating pressure when the active stylus pen contacts the touch screen, a button state indicating whether the at least one functional button provided in the active stylus pen performs a specific function, An active stylus pen that contains information, identification of the pen to distinguish it from other active stylus pens. The method according to claim 1,
Wherein the touch screen driving signal further comprises a beacon signal including a pen operation mode, hovering or contact contact, and whether to transmit tilt data. 9. The method of claim 8,
Wherein the sub pulse and the beacon signal are implemented as a patterned ping signal as a synchronization signal for synchronization between the main pulse and the pen drive signal. 10. The method of claim 9,
Wherein the synchronization signal is implemented in a patterned DSSS (Direct Sequence Spread Spectrum) code. 10. The method of claim 9,
Wherein a plurality of bits are assigned according to a pattern of the synchronization signal so that a command is transmitted from the touch screen to the active stylus pen to secure various additional functions. With a touch screen,
A touch driver for applying a touch screen driving signal to the touch screen and sensing a capacitance change of the touch screen,
And an active stylus pen for generating a pen driving signal and transmitting the pen driving signal to the touch screen,
The active stylus pen includes:
A first signal processing unit for generating a touch frame recognition signal for distinguishing a touch frame based on a sub pulse corresponding to a part of each touch screen driving signal received from the touch screen; And
Generating a pen drive signal so that the pen drive signal is synchronized with the main pulse except for the sub pulse in each touch screen drive signal, And a second signal processing unit that varies the input signal. 13. The method of claim 12,
Wherein the first signal processor comprises:
A first count value is generated by counting a first sub pulse of one touch screen driving signal and a second sub pulse of another touch screen driving signal neighboring the one touch screen driving signal, And generates the touch frame recognition signal when a preset threshold value is exceeded. 13. The method of claim 12,
Wherein the first signal processor comprises:
Generating a second count value by counting the sub pulses included in each of the touch screen driving signals and generating the touch frame recognition signal when the second count value satisfies a preset value. 13. The method of claim 12,
Wherein the second signal processing unit comprises:
And the pulse amplitude of the pen drive signal is varied in units of touch frames according to the touch frame recognition signal so that the pen additional information is reflected in the pen drive signal. 13. The method of claim 12,
Wherein the second signal processing unit comprises:
Wherein the pulse duty of the pen drive signal is varied in units of touch frames according to the touch frame recognition signal so that the pen additional information is reflected in the pen drive signal. 17. The method according to any one of claims 12 to 16,
Wherein the second signal processing unit comprises:
And a pen drive signal in which the pen additional information is reflected is allocated to one touch frame by one bit. 13. The method of claim 12,
Wherein the pen additional information includes at least one of a pressure information indicating pressure when the active stylus pen contacts the touch screen, a button state indicating whether the at least one functional button provided in the active stylus pen performs a specific function, Information, and pen identification information to distinguish it from other active stylus pens. 13. The method of claim 12,
Wherein the touch screen driving signal further comprises a beacon signal including a pen operation mode, hovering or contact contact, and whether to transmit tilt data. 20. The method of claim 19,
Wherein the sub pulse and the beacon signal are implemented as a patterned ping signal as a synchronization signal for synchronization between the main pulse and the pen drive signal. 21. The method of claim 20,
Wherein the synchronization signal is implemented in a patterned DSSS (Direct Sequence Spread Spectrum) code. 21. The method of claim 20,
Wherein a plurality of bits are allocated according to a pattern of the synchronization signal so that a command is transmitted from the touch screen to the active stylus pen to secure various additional functions. Contacting the active stylus pen with a touch screen to receive a touch screen drive signal from the active stylus pen,
Generating a pen driving signal in the active stylus pen so as to be synchronized with the received touch screen driving signal and outputting the pen driving signal to the touch screen;
Sensing the capacitance change of the touch screen in accordance with the touch screen drive signal and the pen drive signal in a touch drive device connected to the touch screen,
Generating the pen driving signal from the active stylus pen and outputting the pen driving signal to the touch screen,
Generating a touch frame recognition signal for identifying a touch frame based on a sub pulse corresponding to a part of each touch screen driving signal received from the touch screen; And
Generating a pen drive signal so that the pen drive signal is synchronized with the main pulse except for the sub pulse in each touch screen drive signal, Wherein the step of changing the sensitivity of the touch sensing system comprises the steps of: 24. The method of claim 23,
Wherein the step of generating a touch frame recognition signal based on the sub-
A first count value is generated by counting a first sub pulse of one touch screen driving signal and a second sub pulse of another touch screen driving signal neighboring the one touch screen driving signal, And generating the touch-frame recognition signal when a preset threshold value is exceeded. 24. The method of claim 23,
Wherein the step of generating a touch frame recognition signal based on the sub-
Generating a second count value by counting the sub pulses included in each of the touch screen driving signals and generating the touch frame recognition signal when the second count value satisfies a preset value. 24. The method of claim 23,
Wherein the step of varying the pen drive signal in units of touch frames according to the touch frame recognition signal so that the pen additional information is reflected in the pen drive signal,
And the pulse amplitude of the pen driving signal is varied in units of touch frames in accordance with the touch frame recognition signal. 24. The method of claim 23,
Wherein the step of varying the pen drive signal in units of touch frames according to the touch frame recognition signal so that the pen additional information is reflected in the pen drive signal,
Wherein the pulse duty of the pen drive signal is varied in units of touch frames in accordance with the touch frame recognition signal. 28. The method according to any one of claims 23 to 27,
Wherein the step of varying the pen drive signal in units of touch frames according to the touch frame recognition signal so that the pen additional information is reflected in the pen drive signal,
And a pen drive signal in which the pen additional information is reflected is allocated to each touch frame by 1 bit. 24. The method of claim 23,
Wherein the pen additional information includes at least one of a pressure information indicating pressure when the active stylus pen contacts the touch screen, a button state indicating whether the at least one functional button provided in the active stylus pen performs a specific function, Information, and pen identification information for distinguishing from other active stylus pens. 24. The method of claim 23,
Wherein the touch screen driving signal further comprises a beacon signal including a pen operation mode, hovering or contact contact, and whether to transmit tilt data. 31. The method of claim 30,
Wherein the sub pulse and the beacon signal are implemented as a patterned ping signal as a synchronization signal for synchronization between the main pulse and the pen drive signal. 32. The method of claim 31,
Wherein the synchronization signal is implemented in a patterned DSSS (Direct Sequence Spread Spectrum) code. 32. The method of claim 31,
Further comprising the step of transmitting a command from the touch screen to the active stylus pen to allocate a plurality of bits according to a pattern of the synchronization signal so that various additional functions can be secured, .

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