KR20170080351A - A touch sensor integrated type display device - Google Patents

Abstract

The present invention relates to a display device including a display panel including a plurality of touch sensors built in a pixel array, a display panel for counting the number of touch points having a touch sensing value higher than a preset reference value among touch sensing values received from the touch sensors, And a touch driver for adjusting the touch gain according to the number of points.

Description

[0001] The present invention relates to a touch sensor integrated type display device,

The present invention relates to a touch sensor built-in display device.

A user interface (UI) enables communication between a person (user) and various electric or electronic devices, allowing a user to easily control the device as desired. 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. In recent years, the user interface has evolved into a touch UI, a voice recognition UI, a 3D UI, and the like, and the touch UI is basically installed in a portable information device. To implement the touch UI, a touch screen is installed on a display element of a home appliance or a portable information device.

The capacitive touch screen has higher durability and sharpness than the conventional resistive touch screen, and has multi-touch recognition and proximity touch recognition, which can be applied to various applications. The electrostatic capacitance type has a mutual capacitance type in which mutual capacitance is used as a touch sensor and a self capacitance type in which a magnetic capacitance is used as a touch sensor. The magneto-capacitance method outputs the output data obtained by applying the touch gain to the touch data input from the touch sensor. Here, the touch gain is a preset value.

The touch data is changed according to the number of touch points touched by the touch sensor. As shown in FIG. 1, when the touch point is single, the touch data has a value of 3K. When the touch point is multi, the touch data has a value between 1K and 2K. That is, as the number of touch points increases, the touch sensitivity decreases.

As shown in FIG. 2, when the touch gain is fixed based on the case where the touch point is a single touch, the touch gain has a low gain value. When touch gain with low gain value is applied to multi touch, the touch data output is small and the touch sensitivity is relatively low.

On the contrary, when the touch gain is fixed based on the case where the touch point is multi-touch, the touch gain has a high gain value. If the touch gain having a high gain value is applied to a case of a single touch, the touch data output increases and exceeds the maximum value of the touch data voltage. Distortion is generated and the touch sensitivity is reduced.

As described above, conventionally, since the same touch gain is applied to both a single touch and a multi-touch, a difference in touch sensitivity occurs in each situation.

SUMMARY OF THE INVENTION It is an object of the present invention to provide a touch sensor built-in display device capable of preventing touch sensitivity from being degraded by adjusting a touch gain according to the number of touch points per frame.

According to an aspect of the present invention, there is provided a display device including a display panel including a plurality of touch sensors incorporated in a pixel array, a display panel including a plurality of touch points having a touch sensing value higher than a predetermined reference value among touch sensing values received from the touch sensors, And a touch driver for adjusting the touch gain according to the counted number of touch points.

The touch driver may adjust the touch gain according to the number of touch points in the first frame and apply the adjusted touch gain to the touch sensing values of the second frame following the first frame.

The touch driver may store the touch sensing values in a memory, adjust the touch gain according to the number of touch points, and apply the adjusted touch gain to the touch sensing values read from the memory.

The touch driver includes a sensing unit for sensing a touch sensing value received from the touch sensors, a comparing unit for comparing the touch sensing values with predetermined reference values, and a comparator for comparing the touch sensing values with a predetermined number of touch points And a gain adjusting unit for adjusting the touch gain according to the number of touch points.

The counter can be initialized at the end of each frame.

The present invention has the effect of preventing the touch sensitivity from being lowered by adjusting the touch gain according to the number of touch points per frame.

The present invention has the effect of improving the reliability of the product by preventing the touch sensitivity from being lowered by adjusting the touch gain according to the number of touch points per frame.

1 is a view showing a touch sensing value when a single touch and a touch sensing value when a touch is multi-touch.
FIG. 2 is a diagram showing a touch gain fixed to a touch sensing value when a single touch and a touch sensing value when a multi-touch is applied.
3 is a view showing a display device according to an embodiment of the present invention.
4 is a view showing an example of a touch sensor built in a pixel array.
5 is a waveform diagram showing signals supplied to a touch sensor, a data line, and a gate line in a display driving period and a touch sensor driving period according to the time division driving method of the present invention.
6 shows multiplexers and sensing units connected to touch sensors;
FIG. 7 shows a configuration of a touch driver according to an embodiment of the present invention.
FIG. 8 is a diagram showing a driving operation of the touch driver of FIG. 7 in order; FIG.
9 is a view showing application of a touch gain adjusted for each frame according to the present invention.
FIG. 10 is a diagram showing a touch sensing value when a single touch and a touch sensing value when a multi-touch according to the present invention. FIG.

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

3 to 7 are views for explaining a display device according to an embodiment of the present invention.

3 to 7, 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 comprises a display module and a touch module.

The display module may include a display panel 10, display drivers 12 and 14, a timing controller 16, and a host system 19

The display panel 10 includes a liquid crystal layer formed between two substrates. The pixel array of the display panel 10 includes pixels 101 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 101 is connected to TFTs (Thin Film Transistors) 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 the voltage of the liquid crystal cell, and the like.

A black matrix, a color filter, or 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 COT (Color Filter On TFT) structure. In this case, the black matrix and the color filter 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 the upper substrate or the lower substrate of the display panel 10. [ On the upper substrate and the lower substrate of the display panel 10, a polarizing plate is attached and an alignment film for forming a pre-tilt angle of the liquid crystal is formed on the inner surface in contact with the liquid crystal. 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 10.

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 to irradiate the display panel 10 with light. The display panel 10 may be implemented in any known liquid crystal mode such as a TN (Twisted Nematic) mode, a VA (Vertical Alignment) mode, an IPS (In Plane Switching) mode, or an FFS (Fringe Field Switching) mode.

The display driver includes a data driver 12 and a gate driver 14 and writes the video data RGB of the input image to the pixels 101 of the display panel 10 under the control of the timing controller 16. The data driver 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 voltages output from the data driver 12 are supplied to the data lines D1 to Dm. The gate driver 14 sequentially supplies a gate pulse (or a scan pulse) synchronized with the data voltage to the gate lines G1 to Gn to select a pixel line of the display panel 10 into 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 driver 12 and the gate driver 14 with each other. The scan timing control signal includes a gate start pulse (GSP), a gate shift clock, a gate output enable signal (GOE), and the like. The data timing control signal includes a source sampling clock (SSC), a polarity control signal (Polarity), a source output enable signal (SOE), and the like.

The host system 19 transmits the timing signals Vsync, Hsync, DE and MCLK together with the digital video data RGB to the timing controller 16 and the touch coordinate information TDATA XY)). ≪ / RTI >

The touch module includes touch sensors (TS1 to TS4) and a touch driver (18) for driving the touch sensors (TS1 to TS4).

The touch sensors TS1 to TS4 may be implemented as capacitive sensors that sense a touch input in a capacitive manner. Capacitance can be divided into Self Capacitance and Mutual Capacitance. The electrostatic capacitance can be formed along a single-layer conductor wiring formed in one direction, and mutual capacitance can be formed between two orthogonal conductor wiring.

The touch sensors TS1 to TS4 may be embedded in the pixel array of the display panel 10 as shown in FIG. 4, the pixel array of the display panel 10 includes touch sensors TS1 to TS4 and sensor lines L1 to Li connected to the touch sensors TS1 to TS4, Positive integer). The common electrode COM of the pixels 101 is divided into a plurality of segments. The touch sensors TS1 to TS4 are implemented as a divided common electrode COM. One common electrode segment is connected in common to the plurality of pixels 101 and forms one touch sensor. The touch sensors TS1 to TS4 supply the common voltage Vcom to the pixels 101 during the display driving periods Td1 and Td2 and input the touch driving signal Vdrv during the touch sensor driving period Tt And senses the touch sensing value. 4 shows the self-capacitance type touch sensor, the touch sensors TS1 to TS4 are not limited thereto.

The touch driver 18 senses the amount of change in the charge of the touch sensors TS1 to TS4 before and after touching to determine whether or not a conductive substance such as a finger (or a stylus pen) is touched and its position. The touch driver 18 counts the number of touch points having a touch sensing value higher than a predetermined reference value among the touch sensing values received from the touch sensors TS1 to TS4, . The touch driver 18 determines the touch sensing value by analyzing the charge variation of the touch sensors TS1 to TS4 depending on the presence or absence of the touch sensing value and calculates coordinates of the touch input position. The coordinate information (TDATA (XY)) of the touch input position is transmitted to the host system 19.

The display device of the present invention temporally separates the period of sensing the touch input and the period of input image data. To this end, the timing controller 16, based on the touch enable signal TEN as shown in FIG. 3, generates a touch sensor driving period Tt for sensing a touch input in one frame period, It can be time-divided by the display driving period Td. Although FIG. 5 shows that one-frame period is divided into one touch sensor driving period Tt and one display driving period Td, the present invention is not limited thereto, and at least one touch sensor driving period Tt) and at least one or more display driving periods (Td).

During the display driving period Td, the data driver 12 supplies the data voltages to the data lines D1 to Dm under the control of the timing controller 16, and the gate driver 14 controls the timing controller 16 A gate pulse synchronized with the data voltage is sequentially supplied to the gate lines G1 to Gn. Meanwhile, during the display driving period Td, the touch driver 18 stops the touch sensing operation.

During the touch sensor driving period Tt, the touch driver 18 drives the touch sensors TS1 to TS4. The touch driver 18 supplies the touch driving signal Vdrv to the touch sensors TS1 through TS4 through the sensor lines L1 through Li to sense the touch sensing value.

During the touch sensor driving period Tt, the display driving units 12 and 14 apply a first driving signal Vdrv synchronized with the touch driving signal Vdrv to the signal lines D1 to Dm and G1 to Gn connected to the pixels 101, And the second AC signals LFD1 and LFD2 to minimize the parasitic capacitance between the signal lines D1 to Dm and G1 to Gn connected to the pixels 101 and the touch sensors TS1 to TS4.

The touch sensor driving unit RIC supplies the touch driving signals Vdrv to the touch sensors TS1 to TS4 during the touch sensor driving period Tt as shown in FIG. The display driving units 12 and 14 supply the first AC signal LFD1 to the data lines D1 to Dm during the touch sensor driving period Tt and the second AC signal LFD2, To the gate lines G1 to Gn. That is, the touch sensor driving unit RIC supplies the touch driving signals Vdrv to the touch sensors TS1 to TS4 during the touch sensor driving period Tt for sensing the touch sensing values, The first AC signal LFD1 having the same phase and amplitude as the touch driving signal Vdrv is supplied to the connected data lines D1 to Dm and the first AC signal LFD1 is supplied to the gate lines G1 to Gn connected to the pixels 101 The second AC signal LFD2 having the same phase and amplitude as the touch driving signal Vdrv is supplied.

The touch sensor driver RIC may include a multiplexer MUX and a sensing unit SU, as shown in FIG. The multiplexer MUX selects the touch sensors TS to be accessed by the sensing unit SU under the control of an MCU (Micro Controller Unit), and then supplies the touch driving signals Vdrv to the selected touch sensors TS.

The sensing unit SU is connected to the sensor lines L1 to Li through a multiplexer MUX to measure a change in the voltage waveform received from the touch sensors TS and convert the measurement result into digital data. The sensing unit SU includes an amplifier for amplifying the voltage of the received touch sensors TS, an integrator for accumulating the voltage of the amplifier, an analog-to-digital converter (hereinafter referred to as " ADC "). The digital data output from the ADC is transferred to the MCU (Micro Controller Unit) as touch raw data.

FIG. 7 shows a configuration of a touch driver according to an embodiment of the present invention.

7, the touch driver according to the embodiment of the present invention counts the number of touch points having a touch sensing value higher than a predetermined reference value among the touch sensor sensing values received from the touch sensors, Set the touch gain according to the number. The touch driver may adjust the touch gain differently according to the single-touch or multi-touch.

The touch driver includes a sensing unit 30, a comparator 31, a counter 32, and a gain adjuster 33.

Since the description of the sensing unit 30 has been fully described above, it will be omitted here.

The comparing unit 31 compares the touch sensing values with preset reference values. The predetermined reference value can be reset by the surrounding environment or the like. If the input touch sensing values are higher than a preset reference value, the comparator 31 outputs the data to the counter 32. If the input touch sensing values are lower than a preset reference value, the comparing unit 31 may determine that the touch is not input or that it is a touch noise.

The counter unit 32 counts the number of touch points when the touch sensing values have a touch sensing value higher than the reference value through the comparing unit 31. [ The counter 32 may receive a touch sensing value higher than the reference value and may store a count obtained by counting the number of touch points in a lookup table or a memory. The counter unit 32 is initialized each time one frame ends. The counter unit 32 is initialized before the start of the frame, and counts the number of touch points in the initialized state. Thus, by initializing every frame, the number of more accurate touch points can be counted.

The gain adjusting unit 33 adjusts the touch gain according to the number of touch points. The gain adjustment unit 33 may store the touch gain according to the number of touch points in a look-up table or a memory. The touch gains stored in the lookup table or memory may be adjusted according to the number of touch points and applied to the touch sensing values. The gain adjustment unit 33 may include a selection unit that can select a touch gain according to the number of touch points. When the number of touch points is " 3 ", the selector performs a switching operation so that the corresponding touch gain # 3 is selected. When the number of touch points is " 2 & When the number of touch points is " 1 ", the touch operation is switched so that the corresponding touch gain # 1 is selected. The touch gain # 1 to the touch gain # 3 have different gain values.

Also, the touch driver stores the touch sensing values in a memory. The touch driver may adjust the touch gain according to the number of touch points and then apply the adjusted touch gain to the touch sensing values read from the memory. Here, the memory does not store only the touch sensing values, but can store the touch gain, the value obtained by counting the number of touch points, and the like.

As described above, the touch driver of the present invention can prevent the touch sensitivity from being lowered regardless of the single-touch or multi-touch by adjusting the touch gain according to the number of touch points.

FIG. 8 shows the driving operation of the touch driver of FIG. 7 in order, FIG. 9 shows application of the touch gain adjusted for each frame according to the present invention, FIG. 10 shows the touch sensing Value and multi-touch touch sensing value.

Referring to FIG. 8, the touch driver of the present invention receives touch sensing values from touch sensors.

The touch sensing values received from the touch sensors are compared with preset reference values. The number of touch points having a touch sensing value higher than a reference value among the touch sensing values is counted (S110).

The counting of the number of touch points can be continuously counted until one frame ends and the next frame starts (S120). When one frame ends, the number of counted touch points can be initialized.

The final count value of the number of touch points having a touch sensing value higher than the reference value among the touch sensing values after one frame ends can be checked and the touch gain can be adjusted according to the final count value. The touch gain can be adjusted upward or downward (S130, S140).

The touch driver may adjust the touch gain according to the number of touch points in the first frame and apply the adjusted touch gain to the touch sensing values of the second frame following the first frame (S150a, S150b, S150c). Referring to FIG. 9, when the number of touch points counted in the first frame is three, the touch gain can be adjusted upward from 2 to 3, and the adjusted touch gain can be applied to the second frame's touch sensing value. And the second frame can be set to 3 by adjusting the touch gain.

When the number of touch points counted in the second frame is 1, the touch gain can be adjusted down from 3 to 1, and the adjusted touch gain can be applied to the touch sensing value of the third frame. The third frame can be set to 1 by adjusting the touch gain.

10 (a) shows a case of multi-touch, and Fig. 10 (b) shows a case of a single touch. In case of multi-touch, the touch gain is adjusted upward because the number of touch points is large. In case of a single touch, the touch gain can be adjusted downward because the number of points is small. As described above, the touch driver of the present invention can easily adjust the touch gain according to the number of touch points. Accordingly, even in a multi-touch condition, the touch sensitivity of a single touch level can be easily secured.

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 panel 12: data driving circuit
14: Gate driving circuit 16: Timing controller
18: touch driver 19: host system
30: ADC 31:
32: Counter section 33: Gain adjustment section

Claims (5)

A display panel including a plurality of touch sensors embedded in the pixel array,
And a touch driver for counting the number of touch points having a touch sensing value higher than a predetermined reference value among the touch sensing values received from the touch sensors and adjusting the touch gain according to the number of the counted touch points, Display device with integrated touch sensor. The method according to claim 1,
Wherein the touch driver adjusts the touch gain in accordance with the number of touch points in a first frame and applies the adjusted touch gain to the touch sensing values of a second frame subsequent to the first frame, Device. The method according to claim 1,
Wherein the touch driver stores the touch sensing values in a memory,
And adjusting the touch gain according to the number of touch points and applying the adjusted touch gain to the touch sensing values read from the memory. The method according to claim 1,
The touch driver
A sensing unit for sensing the touch sensing value received from the touch sensors;
A comparator for comparing the touch sensing values with a predetermined reference value,
A counter for counting the number of touch points having a sensing value higher than the reference value among the touch sensing values through the comparator;
And a gain adjuster for adjusting the touch gain according to the number of touch points. The method of claim 3,
Wherein the counter unit is initialized at the end of one frame.

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