KR20170081127A - Touch sensing system including active stylus pen - Google Patents

Abstract

The present invention is a touch sensing system in which one frame is time-divided into at least one of a touch driving period and a display driving period, and includes an active stylus pen for generating a first pen driving signal and a second pen driving signal, and a touch driving device.
The touch driving device applies a touch driving signal to the touch screen, senses a first pen driving signal input through the touch screen within a first period of the touch driving period, Sensing the second pen drive signal input via the second pen drive signal.

Description

{TOUCH SENSING SYSTEM INCLUDING ACTIVE STYLUS PEN}

The present invention relates to a touch sensing system capable of touch input through an active stylus pen.

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 drive signal, that is, a change in the charge of the touch sensor Touch input is detected.

Recently, a stylus pen is 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. The passive stylus pen is difficult to detect the touch position because of the small change in capacitance at the point of contact with the touch screen. On the other hand, since the active stylus pen generates a pen driving signal by itself and outputs the pen driving signal to the contact point with the touch screen, the touch position detection is easier than the passive type, and development thereof is concentrated.

In the conventional touch sensing system, the active stylus pen transmits pen additional information such as pressure information to the touch IC (Integrated Circuit) separately from the pen driving signal in order to realize various convenience functions. To this end, the conventional active stylus pen individually transmits the pen driving signal and the pen additional information to the touch IC using a modulation method using high frequency (several to several tens of MHz), and the touch IC is a band pass filter And a detection circuit to separate and process the pen driving signal and the pen additional information. These pen drive signals and pen additional information were much higher in frequency than the touch drive signals driving the touch screen.

This conventional touch sensing system has a problem that the size and manufacturing cost of the touch IC are increased because a complicated processing circuit must be added in the touch IC to separate the pen driving signal and the pen additional information.

Furthermore, the conventional touch sensing system can be applied only to an add-on type touch screen and can not be applied to an in-cell type touch screen. The add-on type means a touch screen forming method for bonding a touch screen to a display panel, and the inser type means a touch screen forming method for incorporating touch sensors of a touch screen into a pixel array of a display panel.

In the in-cell type, since the touch sensors are coupled to the pixel signal lines through the parasitic capacitance, the RC delay in the touch screen is larger than in the add-on type. Therefore, it is difficult to accurately transmit the high-frequency pen drive signal and the pen additional information as in the conventional touch sensing system to the touch IC due to the lack of the RC time in the in-cell type touch screen.

SUMMARY OF THE INVENTION It is therefore an object of the present invention to provide a touch sensing system in which a touch sensor has an insole type touch screen and an active stylus pen embedded in a pixel array of a display panel, And the like.

In order to achieve the above object, the present invention provides a touch sensing system in which one frame is divided into at least one of a touch driving period and a display driving period, wherein a touch input is performed in synchronization with a touch driving signal input from a touch screen during the touch driving period And a second pen drive signal for detecting an additional input associated with the additional function of the pen, and for outputting the first pen drive signal and the second pen drive signal to the touch screen continuously And a second stylus pen driver for applying the touch driving signal to the touch screen, sensing the first pen driving signal inputted through the touch screen within a first period of the touch driving period, And a second period of the touch driving period, And a touch drive device for sensing the second pen drive signal.

In addition, in the touch-driving device of the present invention, one frame is divided into at least one of a touch driving period and a display driving period and is operated in the touch driving period, and the touch driving signal is generated and applied to the touch screen during the touch driving period , Sensing a first pen drive signal applied to the touch screen from the stylus pen within a first period of the touch drive period, sensing the first pen drive signal from the stylus pen within a second period of the touch drive period subsequent to the first period, And senses the second pen drive signal applied to the screen. Here, the first pen driving signal and the second pen driving signal are synchronized with the touch driving signal, the first pen driving signal is for detecting a touch input, and the second pen driving signal is for controlling the stylus pen For detecting an additional input related to the additional function.

First, the present invention adds a circuit for digitally processing a sensed value of a second pen drive signal to a conventional touch sensor of an in-cell type to precisely receive digital additional information (pressure, button, pen ID, etc.) can do.

Second, since the first pen drive signal and the second pen drive signal are temporally separated from each other by the touch driving signal, the present invention enables more accurate information transmission.

Third, the present invention can transmit 2048 or more pressure information in the same manner as the touch report rate through digital additional information.

Fourth, the present invention can transmit two or more button information (eraser, barrel, etc.) through digital additional information.

Fifth, the present invention can transmit a pen ID through the digital additional information to simultaneously recognize a plurality of pens.

Sixth, the present invention can process digital additional information into three states and transmit more additional information within a limited time.

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.
FIG. 3 is a view showing an example of a touch screen provided in the display device of FIG.
FIG. 4 is a view showing an example of a touch screen provided in the display device of FIG. 2, which is implemented by an insensitive type capacitive sensor. FIG.
5 is a view showing an internal configuration of an active stylus pen according to the present invention.
FIG. 6 is a diagram illustrating that a first pen driving signal and a second pen driving signal are continuously output in synchronization with a touch driving signal during a touch driving period in an active stylus pen according to the present invention. FIG.
7 is a diagram illustrating a second pen driving signal generated in an amplitude modulation method in synchronism with a touch driving signal in an active stylus pen according to the present invention.
8 is a diagram illustrating a second pen driving signal generated in a frequency modulation manner in synchronism with a touch driving signal in an active stylus pen according to the present invention.
FIG. 9 is a view showing a touch driving device provided in the display device of FIG. 2. FIG.
10 is a diagram illustrating a configuration for digitally processing a sensing value for a second pen drive signal in the touch driver of FIG.
Fig. 11 and Fig. 12 are waveform diagrams for explaining the operation timing of the touch driver of Fig. 9; Fig.
13 and 14 illustrate a second pen drive signal generated in a 3-state in synchronism with a touch drive signal in an active stylus pen according to the present invention.
15 is a diagram showing a possible amount of information transmission when the second pen drive signal is generated in a three-state;

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Reference will now be made in detail to the preferred embodiments of the present invention, examples of which are illustrated in the accompanying drawings. Like reference numerals throughout the specification denote substantially identical components. In the following description, a detailed description of known functions and configurations incorporated herein will be omitted when it may make the subject matter of the present invention rather unclear.

1 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 is implemented as an in-cell type touch screen in which the touch sensors are 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 4 and Figs. 9 to 12. Fig.

The active stylus pen 20 operates in the Rx mode and the Tx mode based on the touch synchronous signal. The active stylus pen 20 generates a first pen driving signal for detecting a touch input in synchronism with a touch driving signal received from the touch screen and a second pen driving signal for detecting an additional input related to the additional function of the pen It is possible to easily detect the touch position on the touch screen by outputting it continuously to the point of contact with the touch screen. In particular, after processing the second pen drive signal to the same frequency as the touch drive signal, Therefore, it is possible to transmit more accurate information. The construction and operation of the active stylus pen 20 will be described later with reference to FIGS. 5 to 8. FIG.

FIG. 2 shows a display device to which a touch sensing system according to an embodiment of the present invention is applied. FIG. 3 and FIG. 4 show that the touch screen of the display device of FIG. 2 is implemented by an in-cell type mutual capacitance sensor and an insensitive type capacitance sensor, respectively.

2 to 4, 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 screen TSP implemented by the mutual capacitive sensor Cm includes Tx electrode lines, Rx electrode lines intersecting the Tx electrode lines, and a plurality of Rx electrode lines at the intersections of the Tx electrode lines and the Rx electrode lines, And the touch sensors Cm formed thereon. The Tx electrode lines are driving signal wirings for supplying a charge to the touch sensors by applying a touch driving signal to each of the touch sensors Cm. The Rx electrode lines are sensor wirings connected to the touch sensors Cm to supply the charges of the touch sensors to the touch driver 18. [ In the mutual capacitance sensing method, a driving signal is applied to the Tx electrode through a Tx electrode line to supply electric charge to the touch sensor (Cm), and the electric potential of the touch sensor (Cm) through the Rx electrode and the Rx electrode line By sensing the capacitance change, the touch input can be detected.

The touch screen TSP implemented by the capacitance sensor Cs may be connected in a one-to-one relationship with the sensor wires 32 formed along one direction of the touch electrodes 31 as shown in FIG. The capacitance sensor Cs includes a capacitance formed in each of the electrodes 31. [ In the capacitance sensing method, when a touch driving signal is applied to the electrode 31 through the sensor wiring 32, the electric charge Q is accumulated in the touch sensor Cs. At this time, when a finger or a conductive object contacts the electrode 31, the parasitic capacitance Cf is further connected to the capacitance sensor Cs to change the total capacitance value. Accordingly, the capacitance value between the finger-touched sensor and the non-touched sensor can be changed to determine whether the finger is touched or not.

The touch sensors Cm or Cs of the touch screen TSP may be embedded in the pixel array of the display panel DIS. In order to embed the touch sensors Cm or Cs into the pixel array, the common electrode of the pixels may be divided into a plurality of segments. In this case, the touch sensors Cm or Cs may be implemented as divided common electrodes. One common electrode segment may be connected in common to a plurality of pixels and form one touch sensor. A common voltage is applied to the common electrode of the pixels during the display driving period, and a touch driving signal and a pen driving signal are applied during the touch driving period.

The touch driver 18 senses the amount of change in the charge of the touch sensor to determine whether or not a conductive substance such as a finger (or a stylus pen) is touched and its position, and calculates a coordinate value XY of the touch input. Further, the touch driver 18 senses the amount of change in the charge of the touch sensor and generates information (PAF) about the additional function of the active stylus pen 20. The information on the additional function of the active stylus pen 20 includes information on whether or not the pressure information, the button function (eraser function, barrel function, etc.) is used, and the ID information.

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 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 ), And information about the pen additional function (PAF).

In this display device 10 of the present invention, one frame is divided into at least one touch driving period (TP in Fig. 6) and a display driving period (DP in Fig. 6). The touch driving period (TP in Fig. 6) is a period in which the touch synchronizing signal (Tsync in Fig. 6) is maintained at the first voltage level and the display driving period (DP in Fig. 6) And is maintained at the second voltage level. The touch synchronous signal (Tsync in Fig. 6) may be generated in the timing controller 16, or in the host system 19.

During the display driving period DP, 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. [ A gate pulse synchronized with the data voltage is sequentially supplied to the gate lines G1 to Gn under the control of the control circuit. On the other hand, during the display driving period DP, the touch driving device 18 stops operating.

During the touch driving period TP, the touch driving device 18 applies a touch driving signal to the touch sensors of the touch screen TSP. During the touch driving period TP, the display driving circuits 12, 14, and 16 are turned on and off in order to minimize 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 driving signal 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.

5 shows the internal structure of the active stylus pen 20 according to the present invention. 6 is a timing chart showing the operation of the active stylus pen 20 according to the present invention when the first pen drive signal PD1 and the second pen drive signal PD2 are consecutively provided in synchronization with the touch drive signal TS during the touch drive period TP . 7 shows a second pen drive signal PD2 generated in an amplitude modulation manner in synchronization with the touch drive signal TS in the active stylus pen 20 according to the present invention. 8 shows a second pen driving signal PD2 generated in a frequency modulation manner in synchronization with the touch driving signal TSP in the active stylus pen 20 according to the present invention.

5 to 8, the active stylus pen 20 of the present invention includes a conductive tip 201, a switching unit 202 connected to the conductive tip 201, a receiving unit 203, The pen drive signal generation unit 205, the parameter selection unit 206 and the transmission unit 207 in synchronization with the touch drive signal TS during the touch drive period TP, And sequentially outputs the signal PD1 and the second pen drive signal PD2.

The conductive tip 201 is made of a conductive material such as metal and serves as a receiving electrode and a transmitting electrode. When the conductive tip 201 is contacted on the touch screen TSP of the display device 20, the conductive tip 201 is coupled to the touch screen TSP at the contact point. The conductive tip 201 receives the touch driving signal TS from the touch screen TSP at the contact point and then outputs the pen driving signal PS generated inside the active stylus pen 20 to the touch screen TSP). Since the conductive tip 201 serves also as a receiving electrode and a transmitting electrode, the structure of the active stylus 20 is simplified.

When the conductive tip 201 is in contact with the touch screen TSP of the display device 20, the switching unit 202 switches the reception timing of the touch driving signal TS and the transmission of the pen driving signal PS Timing is separated in time. The switching unit 202 transmits the touch driving signal TS inputted from the touch screen TSP to the receiving unit 203 through the conductive tip 201 in the Rx mode and outputs the touch driving signal TS to the pen driving signal generating unit 205 in the Tx mode. To the touch screen (TSP) through the conductive tip (201).

The receiving unit 203 includes at least one amplifier and a comparator and digitally processes the touch driving signal Ts inputted through the switching unit 202. [

The validity checking unit 204 analyzes the touch driving signal Ts with reference to the validity condition of the set default parameter set after receiving the touch driving signal Ts from the receiving unit 203, Lt; / RTI > Specifically, the validity checker 204 determines that the number of consecutive pulses of N (N is a positive integer equal to or larger than 2) pulses are equal to the validity condition (valid period PE) of the default parameter set Effective duty DT) is satisfied, it is possible to determine that the touch driving signal TS is valid. In this case, the validity checker 204 switches the switching unit 202 to the Tx mode.

When it is determined by the validity checking unit 204 that the touch driving signal TS is valid, the pen driving signal generating unit 205 generates a pen driving signal TS synchronized with the touch driving signal TS based on the signal generation condition of the default parameter set And generates a signal PS. In other words, the pen drive signal generating unit 205 synchronizes the touch drive signal TS with the signal generation conditions (cycle, duty, number, etc.) of the default parameter set loaded in the register after a certain time delay from the Tx mode switching time The pen drive signal PS can be generated.

Here, the pen drive signal PS includes a first pen drive signal PD1 for detecting a touch input and a second pen drive signal PD2 for detecting an additional input related to the additional function of the pen. The first pen drive signal PD1 is synchronized with the first frequency f1 component of the touch drive signal TS and the second pen drive signal PD2 is synchronized with the second frequency f2 component of the touch drive signal TS Lt; / RTI > The touch driving signal TS may be input at the first frequency f1 during the first period of the touch driving period TP and at the second frequency f2 during the second period of the touch driving period TP . The first frequency f1 and the second frequency f2 may be different from each other as shown in FIG. 11, or may be equal to each other as shown in FIG.

When the first frequency f1 and the second frequency f2 are equal to each other, the second pen drive signal PD2 has the same frequency as the first pen drive signal PD1 (see FIG. 12). On the other hand, when the first frequency f1 and the second frequency f2 are different from each other, the second pen drive signal PD2 has a different frequency from the first pen drive signal PD1 (see FIG. 11). The second frequency f2 is increased with respect to the first frequency f1 so that the second pen drive signal PD2 is driven by the first pen drive signal PD1 in order to transmit a large amount of additional function information within a limited second period, It is preferable to have a higher frequency than that of the first embodiment.

The pen drive signal generating unit 205 can generate the second pen drive signal PD2 through the amplitude modulation method as shown in FIG. 7 in synchronization with the second frequency (f2) component of the touch drive signal TS. The pen drive signal generating unit 205 generates the pen drive signal using the first voltage level V1 representing the digital information "1 " and the second voltage level V2 representing the digital information" 0 & And implements various preset additional functions as the second pen drive signal PD2. According to the amplitude modulation scheme, the second pen drive signal PD2 includes various combinations of the first voltage level V1 and the second voltage level V2, that is, the first pulses having the first amplitude A1, And a second pulse having a second amplitude A2. The pen drive signal generating unit 205 can generate the second pen drive signal PD2 through the frequency modulation method as shown in Fig. 8 in synchronization with the second frequency f2 component of the touch drive signal TS. The pen drive signal generating unit 205 generates a pen drive signal using the first frequency fa representing the digital information "1 " and the second frequency fb representing the digital information" 0 " And implements various additional functions as the second pen drive signal PD2. That is, according to the frequency modulation method, the second pen drive signal PD2 includes various combinations of the first frequency fa and the second frequency fb, i.e., the first pulses having the first pulse width W1, And a second pulse having a second pulse width W2. Since the width of the second pen drive signal PD2 is inversely proportional to the frequency, the width W1 for the first frequency fa is wider than the width W2 for the second frequency fb.

Specifically, when the touch drive signal TS has the same frequency in the first period SS1 and the second period SS1 as shown in FIG. 12, the second pen drive signal PD2 is the first pen drive signal PD1 ) And a plurality of second pulses having a first amplitude A1 and a second plurality of pulses having a second amplitude A1 different from the first amplitude, as shown in FIG. 7 .

When the touch drive signal TS has the same frequency in the first period SS1 and the second period SS2 as shown in Fig. 12, the second pen drive signal PD2 is the first pen drive signal PD1, As shown in FIG. 8, a plurality of first pulses having a first pulse width W1 and a plurality of second pulses having a second pulse width W2 different from the first pulse width, .

On the other hand, when the touch driving signal TS has a higher frequency in the second period SS2 than the first period SS1 as shown in Fig. 11, the second pen driving signal PD2 is the first pen driving signal PD1 As shown in FIG. 7, a plurality of first pulses having a first amplitude A1 and a plurality of second pulses having a second amplitude A1 different from the first amplitude, as shown in FIG. 7, do.

When the touch driving signal TS has a higher frequency in the second period SS2 than the first period SS1 as shown in Fig. 11, the second pen driving signal PD2 is the first pen driving signal PD1 As shown in FIG. 8, a plurality of first pulses having a first pulse width W1 and a plurality of second pulses having a second pulse width W2 different from the first pulse width, Pulses.

The transmission unit 207 amplifies the voltage level of the pen drive signal PS input from the pen drive signal generation unit 205 including the level shifter, and then applies the amplified voltage level to the switching unit 202.

Fig. 9 shows the touch driver 18 provided in the display device of Fig. Fig. 10 shows a configuration for digitally processing the sensing value for the second pen drive signal PD2 in the touch-driving device 18 of Fig. Figs. 11 and 12 are waveform diagrams for explaining the operation timing of the touch driver of Fig. 9. Fig.

The touch driver 18 according to the embodiment of the present invention can be implemented in an IC (Integrate Circuit) package.

9 to 12, the touch driver 18 includes a touch integrated IC (SRIC) and a microcontroller unit (MCU). The touch integrated IC (SRIC) includes a sensing unit (SUT), an analog-to-digital converter (ADC), a comparator (COMP), a digital controller (CTR), a switching unit (SW)

The sensing unit SUT is connected to sensor wirings of the touch screen TSP to apply the touch driving signal TS to the touch screen TSP and to input the touch input by the first pen driving signal PD1 And senses the pen-added input by the second pen drive signal PD2. To this end, the sensing unit SUT includes a touch driving signal supply unit (not shown), a touch sensor channel unit (or channel mux), a plurality of sensing units AFE, and a MUX. The touch sensor channel portion is connected to the electrodes of the touch sensors through sensor wirings (or Rx electrode lines). The touch sensor channel part connects the sensor wires to the sensing parts (AFE). The sensing units AFE sense the charge amount of the touch sensors inputted through the sensor wirings. The sensing units AFE sense the amount of charge by the first pen drive signal PD1 input through the touch screen TSP in the first period SS1 of the touch drive period TP and output the first period SS1 ) Senses the amount of charge by the second pen drive signal PD2 input through the touch screen TSP in the second period SS2 of the touch drive period TP. The MUX connects the sensing units AFE to the switching unit SW one by one in the first to nth touch driving periods (see FIGS. 11 and 12) according to the touch synchronizing signal Tsync.

The switching unit SW is switched in accordance with the time division control signal CONT from the digital controller CTR to output the output terminal of the sensing unit SUT during the first period SS1 of each touch driving period 1 to n to the analog Digital converter ADC and connects the output terminal of the sensing unit SUT to the input terminal of the comparator COMP during the second period SS2 of each touch driving period 1 to n.

During the first period SS1 of each of the touch driving periods 1 to n, the analog-to-digital converter ADC converts the analog sensing value for the touch input (i.e., the charge amount by the first pen drive signal PD1) To a sensing value.

During the second period SS2 of each of the touch driving periods 1 to n, the comparator COMP compares the analog sensing value for the additional input (i.e., the amount of charges by the second pen drive signal PD2) Vref) to generate a digital additional sensing value. When the second pen drive signal PD2 is a combination of the first voltage level V1 and the second voltage level V2 according to the amplitude modulation method shown in Fig. 7, the amount of charge by the first voltage level V1 is Is generated as digital information "1" because it is larger than the reference value Vref, and the amount of charge due to the second voltage level V2 is smaller than the reference value Vref. When the second pen drive signal PD2 is a combination of the first frequency fa and the second frequency f2 according to the frequency modulation method as shown in FIG. 8, the amount of charge due to the first frequency fa is smaller than the reference value Vref , And the amount of charge due to the second frequency f2 is smaller than the reference value Vref, so that it can be generated as digital information "0 ".

The digital controller (CTR) stores the digital touch sensing value from the analog to digital converter (ADC) in the first memory and the digital additional sensing value from the comparator COMP in the second memory. The digital controller CTR generates a time division control signal CONT for distinguishing the first and second periods SS1 and SS2 from each other in the touch driving periods 1 to n and outputs the time division control signal CONT to the switching unit SW Supply. The digital controller CTR transmits the digital touch sensing value stored in the first memory and the digital additional sensing value stored in the second memory to the microcontroller unit (MCU) through the SPI (Serial Peripheral Interface) method.

The microcontroller unit (MCU) calculates the coordinate value of the touch input based on the digital touch sensing value, generates information about the additional function of the pen based on the digital additional sensing value, And transmits information (PAF) about the additional function to the host system.

13 and 14 show a second pen drive signal generated in a three-state in synchronization with a touch driving signal in the active stylus pen according to the present invention. 15 shows a possible amount of information transfer when the second pen drive signal is generated in a 3-state.

13 and 14, the active stylus pen generates the first pen driving signals Pen1 to Pen4, ... in some of the touch driving periods TP of one frame, and the remaining touch driving periods TP The second pen drive signals Data1 to Data6, ... are generated. The first pen drive signals Pen1 through Pen4 and the second pen drive signals Data1 through Data6 are output to the touch screen during the display drive period DP. The first period of the touch driving period in which the first pen driving signals Pen1 to Pen4, ... are generated and the second period of the touch driving period in which the second pen driving signals Data1 to Data6, ... are generated Are arranged in different touch driving periods (TP) with the display driving period (DP) interposed therebetween.

When the second pen drive signals (Data1 to Data6, ...) indicating the additional input related to the pen additional function are outputted to the touch screen through the separate touch drive period TP, the sensitivity of the additional input is improved . Further, since the first pen drive signals Pen1 through Pen4, ... and the second pen drive signals Data1 through Data6, ... are output to the touch screen with the display drive period DP in between, Since the sensing data can be processed during the period DP, a sufficient time for data processing can be secured.

The second pen drive signals Data1 to Data6, ... may have a three-state to increase the amount of information transfer to the additional input. For example, the second pen drive signals Data1 to Data6,... May include first state ('0') signals having the same phase as the touch drive signal TS, (&Apos; 1 ') signals, and third state (' Passive ' signals) for deactivating the active stylus pen.

If the second pen drive signals (Data1 to Data6, ...) are implemented in a three-state, three-bit effects can be created with two bits, so that more additional function information can be transmitted with limited data, . In addition, the same performance can be obtained with a shorter driving time than when two-state ('0', '1') implementation is performed, which is effective in reducing power consumption.

As an example, if the second pen drive signals (Data1 to Data6, ...) are implemented in a three-state, 27 pieces of information can be transmitted in the case of three symbols as shown in FIG. On the other hand, if the second pen drive signals (Data1 to Data6, ...) are implemented in a two-state, only eight pieces of information can be transmitted in the case of three symbols.

Although not shown in Figs. 13 and 14, the first period of the touch driving period in which the first pen driving signals Pen1 to Pen4, ... are generated and the second period of the second pen driving signals Data1 to Data6, The touch driving signal TS may have the same frequency in the second period of the touch driving period in which the touch driving signal TS is generated.

In this case, the second pen drive signals (Data1 to Data6, ...) have the same frequency as the first pen drive signals (Pen1 to Pen4, ...) The first state signals '0', the second state signals '1' which are opposite in phase to the touch driving signal TS, and the third state signals &Quot; Passive ").

Although not shown in Figs. 13 and 14, the second pen drive signals Data1 to Data6,..., And the second pen drive signals Data1 to Data6, In the second period of the touch driving period in which the touch driving signal TS is generated, the touch driving signal TS may have a higher frequency.

In this case, the second pen drive signals Data1 to Data6, ... have higher frequencies than the first pen drive signals Pen1 to Pen4, ..., The first state signals '0', the second state signals '1', which are opposite in phase to the touch driving signal TS, and the third state signals, (&Quot; Passive ").

In FIG. 13, the 'Beacon' signal is a signal for informing the stylus pen about the pen frequency, the pen driving method (contact, hovering), and the panel driving state (basic driving, low power driving).

The present invention has the following effects.

First, the present invention adds a circuit for digitally processing a sensed value of a second pen drive signal to a conventional touch sensor of an in-cell type to precisely receive digital additional information (pressure, button, pen ID, etc.) can do.

Second, since the first pen drive signal and the second pen drive signal are temporally separated from each other by the touch driving signal, the present invention enables more accurate information transmission.

Third, the present invention can transmit 2048 or more pressure information in the same manner as the touch report rate through digital additional information.

Fourth, the present invention can transmit two or more button information (eraser, barrel, etc.) through digital additional information.

Fifth, the present invention can transmit a pen ID through the digital additional information to simultaneously recognize a plurality of pens.

Sixth, the present invention can process digital additional information into three states and transmit more additional information within a limited time.

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

Claims (22)

A touch sensing system in which one frame is time-divided into at least one of a touch driving period and a display driving period,
A second pen driving signal for detecting a touch input and a second pen driving signal for detecting an additional input related to an additional function of the pen are generated in synchronization with a touch driving signal input from the touch screen in the touch driving period, An active stylus pen for outputting the first pen drive signal and the second pen drive signal to the touch screen; And
Wherein the controller is configured to apply the touch driving signal to the touch screen, sense the first pen driving signal inputted through the touch screen within a first period of the touch driving period, And a touch driver for sensing the second pen drive signal input via the touch screen. The method according to claim 1,
Wherein the active stylus pen successively outputs the first pen drive signal and the second pen drive signal to the touch screen,
Wherein the first period and the second period of the touch driving period are continuously arranged within the same touch driving period. 3. The method of claim 2,
Wherein the active stylus pen generates the second pen driving signal through an amplitude modulation method or a frequency modulation method in synchronization with the touch driving signal. 3. The method of claim 2,
Wherein the touch driving signal has the same frequency in the first period and the second period,
The second pen drive signal having a same frequency as the first pen drive signal and a plurality of first pulses having a first amplitude and a plurality of second pulses having a second amplitude different from the first amplitude, Comprising a touch sensing system. 3. The method of claim 2,
Wherein the touch driving signal has the same frequency in the first period and the second period,
Wherein the second pen drive signal has the same frequency as the first pen drive signal and has a plurality of first pulses having a first pulse width and a plurality of pulses having a second pulse width different from the first pulse width, 2 < / RTI > pulses. 3. The method of claim 2,
Wherein the touch driving signal has a higher frequency in a second period than the first period,
The second pen drive signal having a higher frequency than the first pen drive signal and having a plurality of first pulses having a first amplitude and a plurality of second pulses having a second amplitude different from the first amplitude, And a touch sensing system. 3. The method of claim 2,

Wherein the touch driving signal has a higher frequency in a second period than the first period,
Wherein the second pen drive signal has a higher frequency than the first pen drive signal and has a plurality of first pulses having a first pulse width and a plurality of second pulses having a second pulse width different from the first pulse width And second pulses. The method according to claim 1,
Wherein the active stylus pen outputs the first pen drive signal and the second pen drive signal to the touch screen during the display driving period,
Wherein the first period and the second period of the touch driving period are disposed within different touch driving periods with the display driving period interposed therebetween. 9. The method of claim 8,
Wherein the touch driving signal has the same frequency in the first period and the second period,
The second pen drive signal has first state signals having the same frequency as the first pen drive signal and having the same phase as the touch drive signal and a second state signal having a phase opposite to the touch drive signal, And third state signals for undoing the active stylus pen. 9. The method of claim 8,
Wherein the touch driving signal has a higher frequency in a second period than the first period,
Wherein the second pen drive signal has a higher frequency than the first pen drive signal and includes first state signals having the same phase as the touch drive signal and a second state signal having a phase opposite to the touch drive signal, And third state signals for undoing the active stylus pen. The method according to claim 1,
The touch-
A sensing unit, connected to sensor wirings of the touch screen, for sensing the touch input by the first pen drive signal and sensing the additional input by the second pen drive signal;
An analog-to-digital converter for converting an analog sensing value for the touch input into a digital touch sensing value,
A comparator for comparing the analog sensing value of the additional input with a predetermined reference value to generate a digital additional sensing value,
A digital controller for storing the digital touch sensing value in a first memory, storing the digital additional sensing value in a second memory, and generating a time division control signal for distinguishing the first period and the second period;
A switching unit that is switched according to the time division control signal and connects the sensing unit and the analog digital converter during the first period and connects the sensing unit and the comparator during the second period;
And a microcontroller unit for calculating a coordinate value of the touch input based on the digital touch sensing value and generating information about the additional function of the pen based on the digital additional sensing value. 1. A touch driver apparatus in which one frame is divided into at least one touch driving period and a display driving period and is operated in the touch driving period,
And a controller for sensing a first pen drive signal applied to the touch screen from the stylus pen within a first period of the touch drive period, Sensing the second pen drive signal applied to the touch screen from the stylus pen within two periods,
Wherein the first pen drive signal and the second pen drive signal are synchronized with the touch drive signal,
Wherein the first pen drive signal is for detecting a touch input and the second pen drive signal is for detecting an additional input related to an additional function of the stylus pen. 13. The method of claim 12,
The first pen drive signal and the second pen drive signal are continuously applied to the touch screen,
Wherein the first period and the second period of the touch driving period are continuously arranged within the same touch driving period. 14. The method of claim 13,
And the second pen drive signal is generated through an amplitude modulation method or a frequency modulation method in synchronization with the touch driving signal. 14. The method of claim 13,
Wherein the touch driving signal has the same frequency in the first period and the second period,
The second pen drive signal having a same frequency as the first pen drive signal and a plurality of first pulses having a first amplitude and a plurality of second pulses having a second amplitude different from the first amplitude, Wherein the touch- 14. The method of claim 13,
Wherein the touch driving signal has the same frequency in the first period and the second period,
Wherein the second pen drive signal has the same frequency as the first pen drive signal and has a plurality of first pulses having a first pulse width and a plurality of pulses having a second pulse width different from the first pulse width, 2 pulses. 14. The method of claim 13,
Wherein the touch driving signal has a higher frequency in a second period than the first period,
The second pen drive signal having a higher frequency than the first pen drive signal and having a plurality of first pulses having a first amplitude and a plurality of second pulses having a second amplitude different from the first amplitude, And a touch panel. 14. The method of claim 13,

Wherein the touch driving signal has a higher frequency in a second period than the first period,
Wherein the second pen drive signal has a higher frequency than the first pen drive signal and has a plurality of first pulses having a first pulse width and a plurality of second pulses having a second pulse width different from the first pulse width And second pulses. 13. The method of claim 12,
Wherein the first pen drive signal and the second pen drive signal are applied to the touch screen during the display driving period,
Wherein the first period and the second period of the touch driving period are disposed within different touch driving periods with the display driving period interposed therebetween. 20. The method of claim 19,
Wherein the touch driving signal has the same frequency in the first period and the second period,
The second pen drive signal has first state signals having the same frequency as the first pen drive signal and having the same phase as the touch drive signal and a second state signal having a phase opposite to the touch drive signal, And third state signals for undoing the active stylus pen. 20. The method of claim 19,
Wherein the touch driving signal has a higher frequency in a second period than the first period,
Wherein the second pen drive signal has a higher frequency than the first pen drive signal and includes first state signals having the same phase as the touch drive signal and a second state signal having a phase opposite to the touch drive signal, And third state signals for undoing the active stylus pen. 13. The method of claim 12,
A sensing unit, connected to sensor wirings of the touch screen, for sensing the touch input by the first pen drive signal and sensing the additional input by the second pen drive signal;
An analog-to-digital converter for converting an analog sensing value for the touch input into a digital touch sensing value,
A comparator for comparing the analog sensing value of the additional input with a predetermined reference value to generate a digital additional sensing value,
A digital controller for storing the digital touch sensing value in a first memory, storing the digital additional sensing value in a second memory, and generating a time division control signal for distinguishing the first period and the second period;
A switching unit that is switched according to the time division control signal and connects the sensing unit and the analog digital converter during the first period and connects the sensing unit and the comparator during the second period;
A microcontroller unit for calculating a coordinate value of the touch input based on the digital touch sensing value and generating information about the additional function of the pen based on the digital additional sensing value.

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