KR102559085B1 - Display device having touch sensor and driving method of the same - Google Patents

Abstract

A display device with a built-in touch sensor according to the present invention includes a plurality of touch block lines composed of a plurality of touch sensors, each touch sensor having a display panel including a plurality of pixels defined by a plurality of gate lines and data lines, a data driver generating a source modulation signal and applying it to the data lines, a gate driver generating a scan-on modulation signal for writing the source modulation signal into the pixels and applying it to the gate lines, and applying a touch driving signal to touch wires connected to the touch sensors of all touch block lines. and a touch sensor driver for selectively sensing only touch block lines other than one touch block line to which the scan-on modulation signal is applied among the touch block lines, wherein the source modulation signal and the scan-on modulation signal are each synchronized with the touch driving signal.

Description

Touch sensor built-in display device and its driving method {DISPLAY DEVICE HAVING TOUCH SENSOR AND DRIVING METHOD OF THE SAME}

The present invention relates to a display device having touch sensors embedded in a pixel array and a method for driving the same.

A user interface (UI) allows 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 an infrared communication function or a radio frequency (RF) communication function, and the like. User interface technology continues to evolve in the direction of enhancing user sensibility and convenience of operation. Recently, user interfaces are evolving into touch UIs, voice recognition UIs, 3D UIs, and the like.

Touch UI is essential for portable information devices such as smart phones, and is being applied to notebook computers, computer monitors, and home appliances. Recently, a technique of embedding touch sensors in a pixel array of a display panel (hereinafter referred to as “in-cell touch sensor”) has been proposed. In the in-cell touch sensor method, touch sensors may be installed on the display panel without increasing the thickness of the display panel.

In-cell touch sensor technology uses electrodes connected to pixels of a display panel as electrodes of touch sensors. For example, the in-cell touch sensor technology may divide a common electrode for supplying a common voltage to pixels of a liquid crystal display device and utilize the divided common electrode patterns as electrodes of touch sensors.

Since the in-cell touch sensor technology utilizes the divided common electrode patterns as electrodes of the touch sensors, when the touch sensors are driven while input image data is written into the pixels, the touch sensing signal may be distorted because display noise is mixed.

In order to reduce the distortion of the touch sensing signal, in the conventional in-cell touch sensor technology, as shown in FIG. 1, one frame period is time-divided into a period for driving pixels (hereinafter referred to as a “display period Td”) and a period for driving touch sensors (hereinafter referred to as a “touch period Tt”) based on the touch synchronization signal Tsync. In the conventional in-cell touch technology, pixels are driven during the display period Td, and for this purpose, a common voltage Vcom is applied to the common electrode patterns COM, a data signal Vdata corresponding to input image data is applied to the data lines D1 and D2, and a gate signal is applied to the gate lines G1 and G2. Conventional in-cell touch technology applies the touch driving signal Tdrv to the common electrode patterns only during the touch period Tt to read the amount of change in charge of the touch sensors, thereby preventing display noise from being mixed with the touch sensing signal.

However, in the conventional in-cell touch sensor technology, it is difficult to sufficiently secure each of the touch period Tt and display period Td within one frame period due to time-division driving. This problem increases as the resolution and frame frequency increase. If the touch period Tt is short, the touch sensing sensitivity is reduced because the time allotted for sensing of each touch electrode is small. If the display period Td is not sufficient, the data charging time for driving the display is insufficient and the quality of the displayed image is degraded.

Accordingly, an object of the present invention is to provide a display device with a built-in touch sensor and a method of driving the same, which increase touch sensing sensitivity by overlapping a touch period with a display period, improve the quality of a display image, and minimize distortion of a touch sensing signal due to display noise.

In order to achieve the above object, a display device with a built-in touch sensor according to the present invention includes a plurality of touch block lines composed of a plurality of touch sensors, each touch sensor including a display panel including a plurality of pixels defined by a plurality of gate lines and data lines, a data driver that converts input image data into a source modulated signal and applies it to the data lines, the source modulated signal being synchronized with a touch driving signal, and a gate driver that generates a gate modulated signal synchronized with the touch driving signal and applies it to the gate lines, and all touch blocks A touch sensor driver for applying a touch driving signal to touch wires connected to touch sensors of lines and selectively sensing only touch block lines other than one touch block line to which the scan-on modulation signal of the gate modulation signal is applied among the touch block lines, and a timing controller for controlling a polarity inversion period of the source modulation signal by analyzing the input image data.

The timing controller analyzes the input image data in a predetermined unit to predict the degree of polarity deviation of the input image, determines the input image data as a problem pattern when the degree of polarity deviation of the input image exceeds a preset reference value, and determines the input image data as a normal pattern when the degree of polarity deviation of the input image does not exceed a preset reference value, and changes the polarity inversion period of the source modulation signal to a second inversion method different from the first inversion method when the input image data is a problem pattern; and an inversion control unit maintaining a polarity inversion period of the source modulation signal as the first inversion method when the input image data has a normal pattern.

The image analysis unit maps the input image data with a polar pattern according to the first inversion method, compares the size of positive data and negative data applied to the same pixel line, and predicts the degree of polarity deviation of the input image in units of pixel lines.

In the present invention, only a scan-off modulation signal is applied from the gate driver to the remaining touch block lines, and the scan-off modulation signal is synchronized with the touch driving signal and blocks writing of the source modulation signal to the pixels.

In the present invention, the source modulation signal, the scan-on modulation signal, and the scan-off modulation signal each change with the same phase as the touch driving signal and the same amplitude as the touch driving signal.

In the present invention, when one touch block line to which the scan-on modulation signal is applied is sequentially selected along a first direction, the touch sensor driver determines a touch block line to be selectively sensed from among the remaining touch block lines along the first direction.

In the present invention, when one touch block line to which the scan-on modulation signal is applied is sequentially selected along a first direction, the touch sensor driver determines a touch block line to be selectively sensed among the remaining touch block lines along a second direction opposite to the first direction.

In the present invention, when one touch block line to which the scan-on modulation signal is applied is sequentially selected along a first direction, the touch sensor driver randomly determines a touch block line to be selectively sensed from among the remaining touch block lines regardless of the first direction.

In the present invention, the source modulation signal, the scan-on modulation signal, and the scan-off modulation signal are each generated according to a ground modulation signal having the same phase and amplitude as the touch driving signal.

The present invention is connected to the classical power supply through the first switch and connected to the base power through the second switch, and the power supply unit for applying the classical power and the base power supply to the data driving unit and the gate driving unit, and the first switch and the second switch are applied to the power supply unit at the same time to apply to the power supply unit. Further includes a controller that cracks down, and a ground modulation signal generator for generating the ground modulation signal and applying to the data driving unit and the gate drive unit.

In the present invention, the ground modulation signal generator applies the ground modulation signal to the data driver and the gate driver only while the first switch and the second switch are turned off.

In the present invention, the source modulation signal is a data voltage modulated according to the ground modulation signal, the scan on modulation signal is a gate high voltage level scan on gate signal modulated according to the ground modulation signal, and the scan off modulation signal is a gate low voltage level scan off gate signal modulated according to the ground modulation signal.

In the present invention, the ground modulation signal generation unit applies the ground modulation signal to the data driver and the gate driver while the first switch and the second switch are turned on, the data driver includes an adder generating the source modulation signal by adding a source signal and the ground modulation signal, the gate driver adds a scan on gate signal and the ground modulation signal to generate the scan on modulation signal, and adds the scan off gate signal and the ground modulation signal to generate the scan off modulation signal It includes an adder that generates

Also, the present invention provides a method for driving a display device with a built-in touch sensor including a plurality of pixels including a plurality of touch block lines composed of a plurality of touch sensors, each touch sensor being defined by a plurality of gate lines and data lines, wherein a data driver converts input image data into a source modulated signal and applies it to the data lines, the source modulated signal being synchronized with a touch driving signal, and a gate driver generating a gate modulated signal synchronized with the touch driving signal and applying the same to the gate lines; , applying a touch driving signal to touch wires connected to touch sensors of all touch block lines, selectively sensing only the touch block lines other than one touch block line to which the scan-on modulation signal of the gate modulation signal is applied among the touch block lines, and controlling a polarity inversion period of the source modulation signal by analyzing the input image data.

According to the present invention, the display period for display writing and the touch period for touch sensing do not temporally separate but overlap each other, thereby solving the problem of insufficient touch sensing time and insufficient display charging time caused by conventional time-division driving. As a result, the present invention can increase the image quality of the display image and the sensitivity of touch sensing.

Furthermore, the present invention spatially separates a display writing position and a touch sensing position within a display panel while overlapping a display period and a touch period, and in particular, by supplying a source modulation signal and a gate modulation signal synchronized with a touch driving signal to data lines and gate lines, respectively, distortion of the touch sensing signal due to display noise can be drastically reduced and touch sensing accuracy can be improved.

Furthermore, according to the present invention, in driving in which writing of input image data and touch sensing are simultaneously performed, the polarity inversion period of the source modulation signal is appropriately controlled according to the degree of polarity deviation of the input image data, so that the influence of noise caused by the polarity deviation of the input image data on the touch sensing result can be suppressed as much as possible.

1 is a diagram showing a conventional time-division driving technique in which one frame period is divided into a touch period and a display period;
2 and 3 are views showing a display device with a built-in touch sensor according to an embodiment of the present invention.
4 is a diagram showing various configurations for controlling the supply of a ground signal and a ground modulation signal according to the present invention;
5 is a diagram showing the configuration of a source & lead-out IC in which a data driver and a touch sensor driver are integrated according to the present invention;
6 is a view showing the configuration of a gate driver of the present invention;
7 is a diagram showing a method of generating a source modulated signal and a gate modulated signal using a ground modulated signal according to the present invention;
8 is a diagram showing another method of generating a source modulated signal and a gate modulated signal using a ground modulated signal according to the present invention;
9 is a diagram showing the configuration of some touch sensors embedded in a pixel array and a read-out IC for driving them.
10 is a diagram showing a pixel array composed of first to fourth touch block lines and driving units for driving the pixel array;
11 is a diagram showing an example of driving signals generated by driving units of FIG. 10;
12 and 13 are diagrams showing examples in which a touch block line on which a source modulation signal is written and a touch block line on which touch sensing is performed are spatially separated from each other according to the drive signals of FIG. 11 .
14 is a diagram showing another example of driving signals generated by driving units of FIG. 10;
15 and 16 are diagrams showing examples in which a touch block line on which a source modulation signal is written and a touch block line on which touch sensing is performed are spatially separated from each other according to the driving signals of FIG. 14;
17 is a diagram showing the configuration of a timing controller for controlling a polarity inversion period of a source modulation signal;
18 is a diagram showing an operation sequence of a timing controller for controlling a polarity inversion period of a source modulation signal;
19 and 20 are diagrams showing examples of controlling a polarity inversion period of a source modulation signal.

Hereinafter, preferred embodiments according to the present invention will be described in detail with reference to the accompanying drawings. Like reference numbers throughout the specification indicate substantially the same elements. In the following description, if it is determined that a detailed description of a known function or configuration related to the present invention may unnecessarily obscure the subject matter of the present invention, the detailed description will be omitted.

2 and 3 show a display device with a built-in touch sensor according to an embodiment of the present invention. And, Figure 4 shows the overall configuration for controlling the supply of the ground signal and the ground modulation signal of the present invention.

2 to 4 , the touch sensor built-in display device 10 of the present invention may be implemented based on a flat panel display device such as a liquid crystal display (LCD), a field emission display (FED), a plasma display panel (PDP), an organic light emitting display (OLED), or an electrophoresis display (EPD). In the following embodiments, it is described that 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 touch sensor built-in display device of the present invention may include a display panel 10, a data driver 12, a gate driver 14, a timing controller 16, a touch sensor driver 18, a host system 19, and a ground modulation signal generator 20. Here, the ground modulation signal generator 20 may be provided inside the touch sensor driver 18 .

The display panel 10 includes a liquid crystal layer formed between two sheets of substrates. The pixel array of the display panel 10 includes pixels PXL formed in a pixel area defined by data lines D1 to Dm, where m is a positive integer and gate lines G1 to Gn, where n is a positive integer. Each of the pixels PXL may include thin film transistors (TFTs) formed at intersections of the data lines D1 to Dm and the gate lines G1 to Gn, a pixel electrode for charging the data voltage, a storage capacitor (Cst) connected to the pixel electrode to maintain the voltage of the liquid crystal cell, and a common electrode (COM).

The common electrode COM of the pixels PXL is divided into a plurality of segments, and the touch sensors TS are implemented with the divided common electrode COM. One common electrode segment is commonly connected to a plurality of pixels PXL and forms one touch sensor TS. A plurality of touch sensors disposed side by side on one line may form one touch block line (TL1 to TL8 in FIG. 9 ). Also, each touch sensor may include a plurality of pixels defined by a plurality of gate lines and data lines. Each of the touch block lines (TL1 to TL8 in FIG. 9 ) overlaps a plurality of pixel lines (L#1 to L#4), and the width of one touch block line is greater than the width of one pixel line. Here, one pixel line is composed of pixels PXL arranged side by side on one line.

A black matrix, a color filter, and the like may be formed on the upper substrate of the display panel 10 . The lower substrate of the display panel 10 may be implemented as a color filter on TFT (COT) structure. In this case, the black matrix and color filters may be formed on the lower substrate of the display panel 10 . The common electrode to which the common voltage is supplied may be formed on an upper substrate or a lower substrate of the display panel 10 . A polarizer is attached to each of the upper and lower substrates of the display panel 10, and an alignment layer for setting a pretilt angle of the liquid crystal is formed on an inner surface in contact with the liquid crystal. A column spacer is formed between the upper substrate and the lower substrate of the display panel 10 to maintain a cell gap of the liquid crystal cell.

A backlight unit may be disposed under the rear surface of the display panel 10 . The backlight unit is implemented as an edge type or direct type backlight unit and irradiates light to the display panel 10 . The display panel 10 may be implemented in any known liquid crystal mode, such as a twisted nematic (TN) mode, a vertical alignment (VA) mode, an in plane switching (IPS) mode, and a fringe field switching (FFS) mode.

The data driver 12 and the gate driver 14 write the input image data RGB into the pixels PXL of the display panel 10 under the control of the timing controller 16 .

The data driver 12 includes a plurality of source driver ICs (Integrated Circuits) (SICs), converts digital image data (RGB) input from the timing controller 16 into an analog positive/negative polarity gamma compensation voltage according to a scan timing control signal to generate a data voltage (source signal), modulates the data voltage according to a ground modulation signal (MGND), and outputs a source modulation signal (Sdrv). Since the size of the data voltage (source signal) changes according to the gray level of the input image, the size of the source modulation signal Sdrv also changes according to the gray level of the input image. The source modulation signal Sdrv output from the data driver 12 is supplied to the data lines D1 to Dm.

The data driver 12 applies the source modulation signal Sdrv, which changes with the same phase and same amplitude as the touch driving signal Tdrv applied to the touch sensors TS, to the data lines D1 to Dm to minimize the parasitic capacitance between the touch sensors TS and the data lines D1 to Dm, thereby reducing the effect of the parasitic capacitance on the touch sensors TS. This is because the voltages of both ends of the parasitic capacitance change simultaneously, and the smaller the voltage difference, the smaller the amount of charge charged in the parasitic capacitance. When the parasitic capacitance between the touch sensors TS and the data lines D1 to Dm is minimized, mixing of display noise into the touch sensing signal is minimized and distortion of the touch sensing signal is prevented.

The gate driver 14 refers to the scan timing control signal to generate a gate pulse synchronized with the data voltage. The gate pulse includes a scan on gate signal having a gate high voltage level and a scan off gate signal having a gate low voltage level. The gate driver 14 modulates a gate pulse according to the ground modulation signal MGND and outputs a scan-on modulation signal and a scan-off modulation signal to the gate lines G1 to Gn to select one display line of the display panel 10 on which the source modulation signal is written. The scan-on modulation signal is for writing the source modulation signal into the pixels, and blocking the source modulation signal from being written into the scan-off modulation signal pixels.

The gate driver 14 applies the gate modulation signal Gdrv, which changes with the same phase and same amplitude as the touch driving signal Tdrv applied to the touch sensors TS, to the gate lines G1 to Gn to minimize the parasitic capacitance between the touch sensors TS and the gate lines G1 to Gn, thereby reducing the effect of the parasitic capacitance on the touch sensors TS. When the parasitic capacitance between the touch sensors TS and the gate lines G1 to Gn is minimized, mixing of display noise into the touch sensing signal is minimized and distortion of the touch sensing signal is prevented.

The gate driver 14 may be composed of a gate driver IC (Integrated Circuit) or may be directly formed on the lower glass substrate of the display panel 10 according to a Gate Driver In Panel (GIP) method. In the description of the embodiment of the present invention, an example in which the gate driver 14 is implemented as a GIP device (GIC) will be described.

The timing controller 16 receives timing signals such as a vertical sync signal (Vsync), a horizontal sync 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 driver 12 and the gate driver 14. 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 vertical polarity control signal (POL), a horizontal polarity control signal (HINV), a source output enable signal (Source Output Enable (SOE)), and the like.

The timing controller 16 analyzes the input image data RGB and controls the polarity inversion period of the source modulation signal Sdrv, thereby maximally reducing touch noise according to the degree of polarity deviation of the input image data RGB. The timing controller 16 can reduce touch noise as much as possible by changing the polarity inversion period of the source modulation signal Sdrv when a problem pattern having a large degree of polarity deviation of the input image data RGB is input in driving in which input image data RGB is written and touch sensing is simultaneously performed within one frame. This will be described later with reference to FIGS. 17 to 20 .

The host system 19 transmits timing signals (Vsync, Hsync, DE, MCLK) together with digital image data (RGB) to the timing controller 16, and can execute an application program associated with touch coordinate information (TDATA(XY)) input from the touch sensor driver 18.

The touch sensor driver 18 drives and senses the touch sensors TS embedded in the pixel array of the display panel 10 including a read-out IC (RIC) and the like. The touch sensors TS may be implemented as capacitive sensors that sense a touch input. Capacitance can be divided into self capacitance and mutual capacitance. Self-capacitance may be formed along a single-layer conductor line formed in one direction, and mutual capacitance may be formed between two orthogonal conductor lines.

The read-out IC (RIC) drives all the touch sensors TS overlapping the image data write timing within the same frame period, but avoids the touch block line where the image data is written, and selectively senses only the touch sensors TS of other touch block lines. That is, the read-out IC (RIC) applies a touch driving signal to touch wires connected to touch sensors of all touch block lines, and selectively senses only the remaining touch block lines except for one touch block line to which a scan-on modulation signal is applied among touch block lines. As such, the read-out IC (RIC) does not temporally separate display writing and touch sensing within the same frame, but spatially separates them within the display panel 10 .

The read-out IC (RIC) and the source driver IC (SIC) can be implemented as a source & read-out IC (SRIC) by integrating into a single chip. A source & lead-out IC (SRIC) may be mounted on a source COF (Chip On Film) (SCOF).

The host system 19 means a system body of an electronic device to which the display device of the present invention is applicable. The host system 19 may be any one of a phone system, a television (TV) 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 receives touch input data (TDATA(XY)) from the touch sensing IC (TIC) and executes an application associated with the touch input.

The ground modulation signal generator 20 generates a ground modulation signal MGND applied to the data driver 12 and the gate driver 14 . As shown in FIG. 4 , the ground modulation signal generation unit 20 is interlocked with the operation of the power supply unit PMIC and the control unit MCU.

The power supply unit PMIC is connected to the high potential power source VCC through the first switch MT1 and connected to the base power source GND through the second switch MT2, and applies the high potential power source VCC and the base power source GND to the data driver 12, the gate driver 14, and the touch sensor driver 18.

The control unit MCU turns on or off the first switch MT1 and the second switch MT2 at the same time to regulate the high potential power supply VCC and the base power supply GND applied to the power supply unit PMIC. The control unit MCU may turn on/off the first switch MT1 and the second switch MT2 at regular intervals as shown in FIG. 11, and may continuously turn on the first switch MT1 and the second switch MT2 as shown in FIG. 14. When the first switch MT1 and the second switch MT2 are turned off, the data driver 12 and the gate driver 14 may float. The control unit MCU may generate a control pulse CPLS having a first amplitude W1 having the same phase as the touch driving signal Tdrv and supply the control pulse CPLS to the ground modulation signal generator 20 .

The ground modulation signal generation unit 20 may generate a ground modulation signal MGND of a second amplitude W2 having the same amplitude as the touch driving signal Tdrv by level-shifting the control pulse CPLS of the first amplitude W1.

The ground modulation signal generation unit 20 may apply the ground modulation signal MGND to the data driving unit 12 and the gate driving unit 14 while the first switch MT1 and the second switch MT2 are turned off.

Meanwhile, the ground modulation signal generation unit 20 may apply the ground modulation signal MGND to the data driving unit 12 and the gate driving unit 14 even while the first switch MT1 and the second switch MT2 are turned on. In this case, the data driver 12 may further include an adder ADD at its output terminal to generate the source modulated signal Sdrv, and the gate driver 14 may further include an adder ADD at its output terminal to generate the gate modulated signal Gdrv.

5 shows the configuration of a source & lead-out IC in which the data driver 12 and the touch sensor driver 18 are integrated. 6 shows the configuration of the gate driver 14 of the present invention.

Referring to FIG. 5 , the source & lead-out IC (SRIC) includes a source driver IC (SIC) that drives the data lines D1 to D5 of the display panel 10 and a read-out IC (RIC) that drives the touch lines SL connected to the touch sensors in the display panel 10.

The source driver IC (SIC) includes a digital-to-analog converter that generates a data voltage (source signal) and an output buffer that stabilizes the data voltage, and supplies the source modulation signal Sdrv synchronized with the touch sync signal Tdrv to the data lines D1 to D5 according to the ground modulation signal MGND.

The read-out IC (RIC) may include a multiplexer (MUX) and a sensing unit (SU). The multiplexer MUX supplies the touch driving signal Vdrv to the touch sensors TS of all touch block lines, and the sensing unit SU generates touch sensing signals T1 to T3 by selectively sensing only the touch block lines to which the source modulation signal Sdrv is not written. The multiplexer MUX supplies the touch drive signal Vdrv to all touch block lines instead of selectively supplying the touch drive signal Vdrv only to the touch block line where touch sensing is performed in order to eliminate the load deviation between the touch sensors TS.

Referring to FIG. 6 , the GIP element GIC implementing the gate driver 14 includes a plurality of stages STG1 to STG4 connected to gate lines G1 to G4. The GIP element GIC supplies a gate modulation signal Gdrv synchronized with the touch synchronization signal Tdrv to the gate lines G1 to G4 according to the ground modulation signal MGND. The scan-on modulation signal SON constituting the gate modulation signal Gdrv is obtained by changing the gate-high voltage level scan-on gate signal according to the ground modulation signal MGND. The source modulation signal charged in the data line is written into the pixels in synchronization with the scan-on modulation signal SON. The scan-off modulation signal SOFF constituting the gate modulation signal Gdrv is obtained by changing the gate-low voltage level scan-off gate signal according to the ground modulation signal MGND. The source modulation signal charged in the data line is blocked from being written to the pixels while the scan off modulation signal SOFF is applied.

7 and 8 show methods of generating a source modulated signal Sdrv and a gate modulated signal Gdrv using the ground modulated signal MGND according to the present invention.

4 and 7 , the ground modulation signal generator 20 may apply the ground modulation signal MGND to the data driver 12 and the gate driver 14 only while the first and second switches MT1 and MT2 are turned off.

Since the data driver 12 floats while the first switch MT1 and the second switch MT2 are turned off, the source signal of the data driver 12 becomes the source modulated signal Sdrv under the influence of the ground modulated signal MGND, and the source modulated signal Sdrv changes with the same phase and the same amplitude as the ground modulated signal MGND. Since the ground modulation signal MGND has the same phase and amplitude as the touch synchronization signal Tdrv, the source modulation signal Sdrv changes with the same phase and the same amplitude as the touch synchronization signal Tdrv, thereby minimizing the parasitic capacitance between the touch sensors TS and the data lines D1 to Dm, thereby reducing the mixing of display noise in the touch sensing signal.

Also, since the gate driver 14 floats while the first switch MT1 and the second switch MT2 are turned off, the gate pulse of the gate driver 14 becomes the gate modulation signal Gdrv under the influence of the ground modulation signal MGND, and the scan-on modulation signal and the scan-off modulation signal change with the same phase and the same amplitude as the ground modulation signal MGND. Since the ground modulation signal MGND has the same phase and amplitude as the touch synchronization signal Tdrv, the gate modulation signal Gdrv changes with the same phase and the same amplitude as the touch synchronization signal Tdrv, and accordingly, parasitic capacitance between the touch sensors TS and the gate lines G1 to Gn is minimized, thereby reducing display noise mixing in the touch sensing signal.

4 and 8 , the ground modulated signal generator 20 may apply the ground modulated signal MGND to the data driver 12 and the gate driver 14 even while the first and second switches MT1 and MT2 are turned on.

In this case, the data driver 12 may further include an adder at an output terminal thereof to generate the source modulation signal Sdrv. The adder in the data driver 12 adds the source signal and the ground modulation signal MGND to output the source modulation signal Sdrv, and the source modulation signal Sdrv changes to the same phase and the same amplitude as the ground modulation signal MGND. Since the ground modulation signal MGND has the same phase and amplitude as the touch synchronization signal Tdrv, the source modulation signal Sdrv changes with the same phase and the same amplitude as the touch synchronization signal Tdrv, thereby minimizing the parasitic capacitance between the touch sensors TS and the data lines D1 to Dm, thereby reducing the mixing of display noise in the touch sensing signal.

In addition, the gate driver 14 may further include an adder at an output terminal thereof to generate the gate modulation signal Gdrv. The adder in the gate driver 14 adds the gate pulse and the ground modulation signal MGND to output the gate modulation signal Gdrv. That is, the adder in the gate driver 14 adds the scan on gate signal VGH and the ground modulated signal MGND to generate the scan on modulated signal SON, and adds the scan off gate signal VGL and the ground modulated signal MGND to output the scan off modulated signal SOFF. The gate modulation signal Gdrv changes with the same phase and the same amplitude as the ground modulation signal MGND. Since the ground modulation signal MGND has the same phase and amplitude as the touch synchronization signal Tdrv, the gate modulation signal Gdrv changes with the same phase and the same amplitude as the touch synchronization signal Tdrv, and accordingly, parasitic capacitance between the touch sensors TS and the gate lines G1 to Gn is minimized, thereby reducing display noise mixing in the touch sensing signal.

9 shows the configuration of some touch sensors embedded in a pixel array and a read-out IC for driving them.

Referring to FIG. 9 , when the resolution of the touch sensors TS is J (horizontal)×K (vertical) (where each of J and K is a positive integer greater than or equal to 2), the number of required multiplexers MUX may be J. Each multiplexer MUX is connected to K touch sensors TS through K touch wires SL, and sequentially connects K touch wires SL to one sensing unit SU. At this time, the touch driving signal Tdrv is simultaneously supplied to all touch sensors TS located on all touch block lines TL1 to TL8.

For example, each multiplexer MUX may selectively connect eight mux channels 1 to 8 respectively connected to eight touch wires SL to one sensing unit SU. When the first mux channel 1 is connected to each sensing unit SU in each of the eight multiplexers MUX, each sensing unit SU converts the amount of charge received from the touch sensors TS of the touch block line 1 TL1 into digital data T1 to TJ. When the second mux channel 2 is connected to each sensing unit SU in each of the eight multiplexers MUX, each sensing unit SU converts the amount of charge received from the touch sensors TS of the touch block line 2 TL2 into digital data T1 to TJ. Similarly, when the eighth mux channel CH8 is connected to each sensing unit SU in each of the eight multiplexers MUX, each sensing unit SU outputs the amount of charge received from the touch sensors TS of the touch block line 8 TL8 as digital data T1 to TJ.

In other words, touch sensing for touch block line 1 (TL1) is performed when the first mux channel (CH1) of the multiplexers (MUX) is connected to each sensing unit (SU), touch sensing for touch block line 2 (TL2) is performed when the second mux channel (CH2) of the multiplexers (MUX) is connected to each sensing unit (SU), and touch sensing for touch block line 8 (TL8) is connected to each sensing unit (SU). This is done when the eighth mux channel CH8 is connected to each sensing unit SU.

The sensing unit SU may include an amplifier that amplifies the received voltage of the touch sensors TS, an integrator that accumulates the voltage of the amplifier, and an analog-to-digital converter (hereinafter referred to as “ADC”) that converts the voltage of the integrator into digital data. The digital data (T1 to TJ) output from the ADC is touch raw data, and the touch raw data is transmitted to a touch controller (not shown).

10 shows a pixel array composed of first to fourth touch block lines TL1 to TL4 and driving units for driving the pixel array. 11 shows an example of driving signals generated by the driving units of FIG. 10 . 12 and 13 show examples in which a touch block line on which a source modulation signal is written and a touch block line on which touch sensing is performed are spatially separated from each other according to the driving signals of FIG. 11 .

10 and 11, the touch sensor driver 18 applies a touch driving signal Tdrv to the touch lines SL connected to the touch sensors TS of all touch block lines TL1 to TL4, and selectively senses only the remaining touch block lines excluding one touch block line to which the scan on modulation signal SON is applied among the touch block lines TL1 to TL4. In FIG. 11 , X1 indicates a period during which the high potential power supply VCC and the base power supply GND are released and the ground modulation signal MGND is applied to the data driver 12 and the gate driver 14 . Further, X2 indicates a period during which the high potential power supply VCC and the base power supply GND are applied to the data driver 12 and the gate driver 14 .

In period ① of the n-th frame Fn, when the source modulation signal Sdrv is written into the pixels of the first touch block line TL1 as the scan-on modulation signal (SON of Gdrv) is sequentially supplied to the gate lines G11, G12, ... of the first touch block line TL1, the touch sensor driver 18 may perform touch sensing for TLa. Here, TLa may include at least one of the remaining touch block lines TL2 , TL3 , and TL4 except for the first touch block line TL1 .

In the period ② of the n-th frame Fn, when the source modulation signal Sdrv is written into the pixels of the second touch block line TL2 as the scan on modulation signal (SON of Gdrv) is sequentially supplied to the gate lines G21, G22, ... of the second touch block line TL2, the touch sensor driver 18 may perform touch sensing on TLb. Here, TLb may include at least one of the remaining touch block lines TL1 , TL3 , and TL4 excluding the second touch block line TL2 .

In the period ③ of the nth frame Fn, when the scan on modulation signal (SON of Gdrv) is sequentially supplied to the gate lines G31, G32, ... of the third touch block line TL3 so that the source modulation signal Sdrv is written into the pixels of the third touch block line TL3, the touch sensor driver 18 can perform touch sensing on TLc. Here, TLc may include at least one of the remaining touch block lines TL1 , TL2 , and TL4 excluding the third touch block line TL3 .

In the period ③ of the nth frame Fn, when the scan on modulation signal (SON of Gdrv) is sequentially supplied to the gate lines G31, G32, ... of the third touch block line TL3 so that the source modulation signal Sdrv is written into the pixels of the third touch block line TL3, the touch sensor driver 18 can perform touch sensing on TLc. Here, TLc may include at least one of the remaining touch block lines TL1 , TL2 , and TL4 excluding the third touch block line TL3 .

In period ④ of the n-th frame Fn, when the source modulation signal Sdrv is written into the pixels of the fourth touch block line TL4 as the scan on modulation signal (SON of Gdrv) is sequentially supplied to the gate lines G41, G42, ... of the fourth touch block line TL4, the touch sensor driver 18 may perform touch sensing on the TLd. Here, TLd may include at least one of the touch block lines TL1 , TL2 , and TL3 excluding the fourth touch block line TL4 .

Meanwhile, as shown in FIG. 12 , when one touch block line to which the scan on modulation signal SON is applied is sequentially selected along the first direction, that is, from top to bottom, the touch sensor driver 18 may determine a touch block line that is selectively sensed among the remaining touch block lines along the first direction. Specifically, when the scan on modulation signal SON is applied to the first touch block line TL1 in period ① of the nth frame Fn, the touch sensor driver 18 may perform touch sensing on the second touch block line TL2. Also, when the scan on modulation signal SON is applied to the second touch block line TL2 in the period ② of the nth frame Fn, the touch sensor driver 18 may perform touch sensing on the third touch block line TL3. Also, when the scan on modulation signal SON is applied to the third touch block line TL3 in the period ③ of the nth frame Fn, the touch sensor driver 18 may perform touch sensing on the fourth touch block line TL4. Also, when the scan on modulation signal SON is applied to the fourth touch block line TL4 in period ④ of the nth frame Fn, the touch sensor driver 18 may perform touch sensing on the first touch block line TL1.

Meanwhile, as shown in FIG. 13 , when one touch block line to which the scan-on modulation signal SON is applied is sequentially selected along the first direction, that is, from top to bottom, the touch sensor driver 18 may determine the touch block line to be selectively sensed among the remaining touch block lines along a second direction (direction from bottom to top) opposite to the first direction. Specifically, when the scan on modulation signal SON is applied to the first touch block line TL1 in period ① of the nth frame Fn, the touch sensor driver 18 may perform touch sensing on the fourth touch block line TL4. Also, when the scan on modulation signal SON is applied to the second touch block line TL2 in the period ② of the nth frame Fn, the touch sensor driver 18 may perform touch sensing on the third touch block line TL3. Also, when the scan on modulation signal SON is applied to the third touch block line TL3 in the period ③ of the nth frame Fn, the touch sensor driver 18 may perform touch sensing on the second touch block line TL2. Also, when the scan on modulation signal SON is applied to the fourth touch block line TL4 in period ④ of the nth frame Fn, the touch sensor driver 18 may perform touch sensing on the first touch block line TL1.

Meanwhile, although not shown, when one touch block line to which the scan-on modulation signal SON is applied is sequentially selected along the first direction, that is, from top to bottom, the touch sensor driver 18 may randomly determine a touch block line that is selectively sensed among the remaining touch block lines regardless of the first direction.

Meanwhile, the touch sensor driver 18 may increase sensing accuracy by simultaneously sensing a plurality of touch block lines among the remaining touch block lines to which the scan-on modulation signal SON is not applied during periods ① to ④, respectively.

14 shows another example of driving signals generated by the driving units of FIG. 10 . 15 and 16 show examples in which a touch block line on which a source modulation signal is written and a touch block line on which touch sensing is performed are spatially separated from each other according to the drive signals of FIG. 14 .

14 to 16 differ from FIGS. 11 to 13 in that the ground modulation signal MGND is applied while the high potential power supply VCC and the base power supply GND are continuously applied to the data driver 12 and the gate driver 14 during each frame (Fn, Fn+1). The touch sensing concept of FIGS. 14 to 16 is substantially the same as that described in FIGS. 11 to 13 .

17 and 18 respectively show the configuration and operation sequence of the timing controller 16 for controlling the polarity inversion period of the source modulation signal. 19 and 20 show examples of controlling the polarity inversion period of the source modulation signal.

17 to 20, the timing controller 16 includes an image analyzer 161 and an inversion controller 162 to minimize the effect of the degree of polarity deviation of the source modulation signal Sdrv on the touch sensing signal.

The image analyzer 161 analyzes the input image data RGB in predetermined units, for example, pixel lines L#1, L#2, L#3, and L#4, predicts the degree of polarity deviation of the input image for each pixel line (L#1, L#2, L#3, and L#4), determines the input image data RGB as a problem pattern when the degree of polarity deviation of the input image exceeds a preset reference value, and determines the input image data RGB as a problem pattern when the degree of polarity deviation of the input image does not exceed the preset reference value. (RGB) may be determined as a normal pattern (S10, S20).

The image analyzer 161 maps the input image data RGB with a polarity pattern according to the first inversion method, and compares the size of the positive data (+) and the negative data (-) applied to the same pixel line (L#1, L#2, L#3, L#4) to predict the degree of polarity deviation of the input image in units of pixel lines (L#1, L#2, L#3, and L#4). Here, the first inversion method may be an inversion method determined as a default value, or may also be an inversion method used in the previous step.

For example, the image analyzer 161 maps the input image data (RGB) as shown in (A) of FIG. 19 with a polar pattern according to the vertical 2-dot inversion method, compares the size of positive data (+) and negative data (-) applied to the same pixel line (L#1, L#2, L#3, and L#4), and determines the degree of polarity deflection for the first to fourth pixel lines (L#1, L#2, L#3, and L#4), respectively. You can predict +2, -2, -4, +4. In FIG. 19 , a pixel PXL displayed in black is a pixel into which black gradation image data having the smallest data size is written, a pixel PXL displayed in color is a pixel into which white gradation image data having the largest data size is written, and a pixel PXL displayed in gray indicates a pixel in which intermediate grayscale image data having a data size larger than black gradation image data and smaller than white gradation image data is written. In the vertical two-dot inversion method, the polarity of the source modulation signal Sdrv continuously output from each output channel of the source driver IC (SIC) is inverted in a repeating pattern of "- - + +" or "+ + - -", and the polarity of the source modulation signal Sdrv simultaneously output from adjacent outputs of the source driver IC (SIC) is inverted in a repeating pattern of "- + - +" or "+ - + -". This vertical 2-dot inversion method may be a default inversion method or may also be an inversion method used in the previous step.

In addition, the image analyzer 161 maps the input image data (RGB) as shown in (A) of FIG. 20 with a polar pattern according to the horizontal 2-dot inversion method, compares the size of positive data (+) and negative data (-) applied to the same pixel line (L#1, L#2, L#3, and L#4) to determine the degree of polarity deflection for the first to fourth pixel lines (L#1, L#2, L#3, and L#4), respectively. You can predict +2, -2, +10, -10. In FIG. 20 , a pixel PXL displayed in black is a pixel into which black gradation image data having the smallest data size is written, a pixel PXL displayed in color is a pixel into which white gradation image data having the largest data size is written, and a pixel PXL displayed in gray indicates a pixel into which intermediate grayscale image data having a data size larger than black gradation image data and smaller than white gradation image data is written. In the horizontal two-dot inversion method, the polarity of the source modulation signal Sdrv continuously output from each output channel of the source driver IC (SIC) is inverted in a repeating pattern of "- + - +" or "+ - + -", and the polarity of the source modulation signal Sdrv simultaneously output from adjacent outputs of the source driver IC (SIC) is inverted in a repeating pattern of "- - + +" or "+ + - -". This horizontal 2-dot inversion method may be a default inversion method or may also be an inversion method used in the previous step.

The image analyzer 161 may determine the input image data RGB as a problem pattern that may cause distortion of the touch sensing signal if the sum of the absolute values of the degree of polarity deflection shown in FIG. 19 (A) or 20 (A) exceeds a preset reference value, and may determine the input image data RGB as a normal pattern that does not affect the touch sensing signal if the sum of absolute values of the degree of polarity deflection does not exceed the reference value.

The inversion control unit 162 changes the polarity inversion period of the source modulation signal Sdrv to a second inversion method different from the first inversion method using the vertical polarity control signal POL and the horizontal polarity control signal HINV when the input image data RGB has a problem pattern, and changes the polarity inversion period of the source modulation signal Sdrv to the first inversion method using the vertical polarity control signal POL and the horizontal polarity control signal HINV when the input image data RGB has a normal pattern. It is maintained as a method (S30, S40).

For example, as shown in (B) of FIG. 19, when the input image data RGB has a problem pattern, the polarity inversion period of the source modulation signal Sdrv is changed from a vertical 2-dot inversion method to a horizontal 2-dot inversion method, thereby lowering the degree of polarity deviation for the first to fourth pixel lines L#1, L#2, L#3, and L#4 to 0, 0, +2, and -2, respectively.

In addition, as shown in (B) of FIG. 20, when the input image data RGB has a problem pattern, the polarity inversion period of the source modulation signal Sdrv is changed from a horizontal 2-dot inversion method to a vertical 2-dot inversion method, thereby lowering the degree of polarity deviation for the first to fourth pixel lines L#1, L#2, L#3, and L#4 to 0, 0, 0, and 0, respectively.

As described above, the present invention overlaps the display period for display writing and the touch period for touch sensing without temporally separating them, thereby solving the problem of insufficient touch sensing time and insufficient display charging time due to conventional time-division driving. As a result, the present invention can increase the image quality of the display image and the sensitivity of touch sensing.

Furthermore, the present invention spatially separates a display writing position and a touch sensing position within a display panel while overlapping a display period and a touch period, and in particular, by supplying a source modulation signal and/or a gate modulation signal synchronized with a touch driving signal to data lines and gate lines, respectively, distortion of the touch sensing signal due to display noise can be dramatically reduced and accuracy of touch sensing can be improved.

Furthermore, according to the present invention, in driving in which writing of input image data and touch sensing are simultaneously performed, the polarity inversion period of the source modulation signal is appropriately controlled according to the degree of polarity deviation of the input image data, so that the influence of noise caused by the polarity deviation of the input image data on the touch sensing result can be suppressed as much as possible.

Through the above description, those skilled in the art will understand that various changes and modifications are possible without departing from the spirit of the present 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 determined by the claims.

10: display panel 12: data driving unit
14: gate driver 16: timing controller
18: touch sensor driver 20: ground modulation signal generator
161: video analysis unit 162: inversion control unit

Claims (27)

a display panel including a plurality of pixels including a plurality of touch block lines including a plurality of touch sensors, each touch sensor being defined by a plurality of gate lines and data lines;
a data driver that converts input image data into a source modulation signal and applies it to the data lines, wherein the source modulation signal is synchronized with a touch driving signal;
a gate driver generating a scan-on modulation signal and a scan-off modulation signal synchronized with the touch driving signal and applying them to the gate lines;
A touch sensor driver that applies a touch driving signal to touch wires connected to touch sensors of all touch block lines and selectively senses only touch block lines other than one touch block line to which the scan-on modulation signal is applied among the touch block lines; and
A timing controller controlling a polarity inversion period of the source modulation signal by analyzing the input image data;
The scan-on modulation signal is a gate-high voltage level scan-on gate signal modulated according to a ground modulation signal having the same phase and amplitude as the touch driving signal;
The scan-off modulation signal is a scan-off gate signal having a gate low voltage level that is modulated according to the ground modulation signal. According to claim 1,
The timing controller,
an image analyzer configured to analyze the input image data in a predetermined unit to predict a degree of polarity deflection of the input image, to determine the input image data as a problem pattern when the degree of polarity deflection of the input image exceeds a preset reference value, and to determine the input image data as a normal pattern when the degree of polarity deflection of the input image does not exceed a preset reference value; and
A display device with a built-in touch sensor including an inversion control unit for changing a polarity inversion period of the source modulation signal to a second inversion method different from a preset first inversion method when the input image data has a problem pattern, and maintaining a polarity inversion period of the source modulation signal in the first inversion method when the input image data is a normal pattern. According to claim 2,
The image analysis unit maps the input image data with a polar pattern according to the first inversion method and compares the size of positive data and negative data applied to the same pixel line to predict the degree of polarity deviation of the input image in units of pixel lines. A display device with a built-in touch sensor. According to claim 1,
Only the scan off modulation signal is applied from the gate driver to the remaining touch block lines;
The scan off modulation signal blocks the writing of the source modulation signal to the pixels. According to claim 1,
The source modulation signal, the scan-on modulation signal, and the scan-off modulation signal each change in the same phase as the touch drive signal and in the same amplitude as the touch drive signal to reduce the effect of parasitic capacitance on the touch sensors. A display device with a built-in touch sensor. According to claim 5,
When the one touch block line to which the scan-on modulation signal is applied is sequentially selected along a first direction,
wherein the touch sensor driver determines a touch block line to be selectively sensed from among the remaining touch block lines along the first direction. According to claim 5,
When the one touch block line to which the scan-on modulation signal is applied is sequentially selected along a first direction,
wherein the touch sensor driver determines a touch block line to be selectively sensed from among the remaining touch block lines along a second direction opposite to the first direction. According to claim 5,
When the one touch block line to which the scan-on modulation signal is applied is sequentially selected along a first direction,
wherein the touch sensor driver randomly determines a touch block line that is selectively sensed from among the remaining touch block lines regardless of the first direction. delete According to claim 1,
The source modulation signal is a data voltage modulated according to the ground modulation signal. According to claim 1,
a power supply unit connected to a high potential power source through a first switch and connected to a base power source through a second switch to apply the high potential power source and the base power source to the data driver and the gate driver;
a control unit controlling the high potential power and the base power applied to the power supply unit by simultaneously turning on or off the first switch and the second switch; and
and a ground modulation signal generator for generating the ground modulation signal and applying the generated ground modulation signal to the data driver and the gate driver. According to claim 11,
The ground modulation signal generating unit,
The touch sensor built-in display device applies the ground modulation signal to the data driver and the gate driver only while the first switch and the second switch are turned off. According to claim 11,
The ground modulation signal generating unit,
applying the ground modulation signal to the data driver and the gate driver while the first switch and the second switch are turned on;
The data driver includes an adder generating the source modulation signal by adding the source signal and the ground modulation signal to each other;
wherein the gate driver includes an adder for generating the scan-on modulated signal by adding the scan-on gate signal and the ground modulated signal, and generating the scan-off modulated signal by adding the scan-off gate signal and the ground modulated signal. A method of driving a display device with a built-in touch sensor including a plurality of pixels including a plurality of touch block lines composed of a plurality of touch sensors and each touch sensor being defined by a plurality of gate lines and data lines, the method comprising:
converting input image data into source modulation signals and applying them to the data lines by a data driver, the source modulation signals being synchronized with the touch driving signals;
generating, by a gate driver, a scan-on modulation signal and a scan-off modulation signal synchronized with the touch driving signal and applying them to the gate lines;
In a touch sensor driver, applying a touch driving signal to touch wires connected to touch sensors of all touch block lines, and selectively sensing only the remaining touch block lines except for one touch block line to which the scan-on modulation signal is applied among the touch block lines; and
Controlling a polarity inversion period of the source modulation signal by analyzing the input image data;
The scan-on modulation signal is a gate-high voltage level scan-on gate signal modulated according to a ground modulation signal having the same phase and amplitude as the touch driving signal;
The scan-off modulation signal is a scan-off gate signal having a gate low voltage level that is modulated according to the ground modulation signal. 15. The method of claim 14,
The step of controlling the polarity inversion period of the source modulation signal,
predicting the degree of polarity deflection of the input image by analyzing the input image data in a predetermined unit, determining the input image data as a problem pattern when the degree of polarity deflection of the input image exceeds a preset reference value, and judging the input image data as a normal pattern when the degree of polarity deflection of the input image does not exceed the preset reference value; and
When the input image data has a problem pattern, changing a polarity inversion period of the source modulating signal to a second inversion method different from a preset first inversion method, and maintaining a polarity inversion period of the source modulation signal in the first inversion method when the input image data is a normal pattern. According to claim 15,
In the step of predicting the degree of polarity deviation of the input image by analyzing the input image data in pixel line units, the input image data is mapped with the polarity pattern according to the first inversion method, and the size of positive data applied to the same pixel line is compared with the size of negative data to predict the degree of polarity deviation of the input image in unit of pixel line. delete delete delete delete delete delete delete delete delete delete delete