KR20140097889A - Touch Screen Integrated Display Device and Method for Driving The Same - Google Patents

Abstract

A display device integrated with a touchscreen according to an embodiment of the present invention includes a display touch panel which has a touchscreen formed in pixels; a driver integrated circuit (IC) which supplies a data voltage according to image data to the pixels of the display touch panel and analyzes the image data to calculate the capacitance variations between touch blocks each comprising a predetermined number of pixels; and a touch IC which supplies a touch driving signal to the touch blocks and compensates the capacitance variations between the touch blocks to sense a touch.

Description

TECHNICAL FIELD [0001] The present invention relates to a touch screen integrated display device and a method of driving the same,

The present invention relates to a touch screen integrated type display device and a method of driving the same, which can improve a touch sensing performance by reducing a touch error due to a screen change.

As mobile electronic devices such as mobile communication terminals and notebook computers are developed, a demand for a flat panel display apparatus that can be applied thereto is increasing.

Examples of flat panel display devices include a liquid crystal display apparatus (LCD), a plasma display panel (PDP), a field emission display apparatus (FED), an organic light emitting diode (OLED) A diode display apparatus, and an electrophoretic display apparatus (EPD) have been developed.

Such flat panel display devices are being applied to the fields of development of mass production technology, ease of driving means, low power consumption, high image quality and large-sized screen realization. A touch screen capable of inputting information directly to a screen by using a finger or a pen instead of a conventional input device such as a mouse or a keyboard has been applied as an input device of a flat panel display device.

The touch screen may include a monitor such as navigation, an industrial terminal, a notebook computer, a financial automation device, a game machine, and the like; A portable terminal such as a mobile phone, MP3, PDA, PMP, PSP, portable game machine, DMB receiver, tablet PC and the like; And household appliances such as refrigerators, microwave ovens, washing machines, and the like, and applications are being expanded due to their ease of operation.

Such a touch screen can be classified into a resistance method, a capacitance method, and an infrared method according to a sensing method, and a capacitance method having excellent manufacturing convenience and sensing performance is most widely applied.

In addition, the touch screen can be classified into an in-cell type that is refracted in a cell of a display panel according to the structure, an on-cell type that is formed on a top of the display panel, and an add-on type in which a touch screen is separately attached to an upper portion of the display device. The insole method, which has advantages of beauty and slimness, is being applied.

FIG. 1 is a view schematically showing a display device including a touch screen according to the related art, and FIG. 2 is a view showing a problem that an auto-touch failure occurs due to a screen change.

Referring to FIG. 1, a display device including a touch screen according to the related art includes a display panel 10, a driver integrated circuit (IC) 20, and a touch integrated circuit (IC) 30.

A plurality of pixels are formed on the display panel 10 and a touch screen is formed by a touch group 12 in units of a predetermined number of pixels (for example, 64 × 64).

A common electrode for supplying the common voltage Vcom to the pixels is formed for each of the touch groups 12. [ At this time, the common electrode of the pixels is used as the touch electrode. The common electrode of each touch group 12 is connected to the touch IC 30 through a separate touch line (not shown), and the common electrode is driven by the touch electrode to sense the user's touch.

In the in-cell touch system, the display and the touch sensing are temporally divided and driven due to a structural characteristic in which a pixel for display and a touch screen for touch detection are formed together.

Here, touch presence and position are sensed by using a capacitance difference between adjacent touch groups. A capacitance variation occurs between a touch block in which a user's finger is touched in a touch sensing period (non-display period) and a touch block in which a touch is not made, and when the touch IC 30 detects a capacitance variation And senses presence / absence and position of the user's touch.

2, when neighboring touch blocks display different images, for example, the first touch block TB1 displays a white image and the second touch block displays a black image, An error may occur.

If the adjacent touch blocks display different images, the electrostatic capacitance is affected by the change of the screen between the touch blocks, which causes a variation in capacitance between the touch blocks.

When the variation of the electrostatic capacitance is larger than the touch judgment reference value, the touch IC 30 determines whether the touch of the user is in a state where the touch block 12 has a touch judgment reference value (for example, 120) . That is, even when there is no actual touch, an auto touch error occurs which is malfunctioning due to a touch, and a serious obstacle occurs in the reliability of the touch sensing when the screen is changed.

On the other hand, the amount of change (? Data) of the touch row data according to the brightness of the image is similar to that of 2.2 gamma curve, and when the touch sensitivity is increased, the amount of change of the touch row data according to the screen change also increases proportionally There is a limitation in increasing the touch sensing performance.

In addition, since the display device including the touch screen according to the related art according to the related art can not respond to defects and rework due to the mass production deviation of the display panel after the manufacture of the display panel is completed, It is difficult to improve.

Accordingly, there is a demand for a touch screen integrated display device and a method of driving the touch screen integrated display device capable of preventing a touch error due to a screen change between touch blocks in a capacitive differential drive system.

SUMMARY OF THE INVENTION The present invention has been made to solve the above-mentioned problems, and it is an object of the present invention to provide a touch screen integrated type display device capable of reducing a touch sensing error, particularly, an auto touch error, And to provide a driving method.

SUMMARY OF THE INVENTION It is an object of the present invention to provide a touch screen integrated type display device and a method of driving the same, which can improve the touch sensing performance of the capacitance displacement driving method.

SUMMARY OF THE INVENTION The present invention has been made to solve the above problems and provides a touch screen integrated type display device and a method of driving the same that can reduce a touch failure rate and rework due to a deviation of a display panel during a mass production.

Other features and advantages of the invention will be set forth in the description which follows, or may be obvious to those skilled in the art from the description and the claims.

According to an aspect of the present invention, there is provided a touch screen integrated display device including: a display touch panel having a touch screen formed in a pixel; A driver IC (Integrated Circuit) for supplying a data voltage according to image data to pixels of the display touch panel and analyzing the image data to calculate a capacitance variation of the touch blocks composed of a certain number of pixels; And a touch IC that supplies a touch driving signal to the touch blocks and senses the touch by compensating for a variation in capacitance between the touch blocks.

According to an aspect of the present invention, there is provided a method of driving a touch screen integrated display device, comprising: calculating capacitance variation between touch blocks by analyzing image data in units of frames; Generating touch correction data for each touch block based on a capacitance variation between the touch blocks; And compensating a capacitance change amount of the touch blocks according to the screen change based on the touch correction data for each touch block, wherein the touch correction data for each touch block is reflected on the sensed touch row data to sense the touch .

INDUSTRIAL APPLICABILITY The touch screen integrated display device and the driving method thereof according to the present invention can reduce a touch error due to a screen change, particularly an auto touch error, when applying a capacitive differential driving method.

INDUSTRIAL APPLICABILITY The touch screen integrated display device and the driving method thereof according to the present invention can improve the touch sensing performance.

The touch screen integrated display device and the driving method thereof according to the embodiment of the present invention can increase the mass productivity of the touch screen integrated display device and reduce the touch defect rate to enhance the product competitiveness.

INDUSTRIAL APPLICABILITY The touch screen integrated display device and the driving method thereof according to the present invention can reduce a touch defect rate and rework due to mass production deviation of a display panel.

In addition, other features and advantages of the present invention may be newly understood through embodiments of the present invention.

1 is a schematic view of a display device including a touch screen according to the related art.
Fig. 2 is a view showing a problem in which an auto-touch failure occurs due to a change in the screen.
3 is a view illustrating a display device including a touch screen according to an embodiment of the present invention.
4 is a view showing a drive IC according to an embodiment of the present invention.
5 to 9 are views illustrating a method of driving a display device including a touch screen according to an embodiment of the present invention.
FIG. 10 is a diagram showing that the touch error is improved by compensating the touch data. FIG.

Hereinafter, a touch screen integrated display device and a driving method thereof according to embodiments of the present invention will be described in detail with reference to the accompanying drawings. Like reference numerals throughout the specification denote substantially identical components. In the following description, detailed descriptions of configurations and functions known in the technical field of the present invention and those not related to the core configuration of the present invention can be omitted.

Prior to the detailed description with reference to the drawings, a liquid crystal display device may include a twisted nematic (TN) mode, a VA (Vertical Alignment) mode, an IPS (In Plane Switching) mode, a FFS Mode and so on.

In the IPS mode and the FFS mode, a pixel electrode and a common electrode are formed on a lower substrate (TFT array substrate), and the alignment of the liquid crystal layer is adjusted by a vertical electric field formed between the pixel electrode and the common electrode .

In particular, in the IPS mode, a pixel electrode and a common electrode are alternately arranged in parallel so that a horizontal electric field is generated between both electrodes to adjust the alignment of the liquid crystal layer.

In the FFS mode, a pixel electrode and a common electrode are formed so as to be spaced apart with an insulating layer therebetween. At this time, one electrode is formed in a plate shape or a pattern and the other electrode is formed in a finger shape. And arranges the liquid crystal layer through a fringe field generated between the pixel electrode and the common electrode.

The touch screen integrated display device according to an embodiment of the present invention can be applied to all liquid crystal panels of TN mode, VA mode, IPS mode and FFS mode. In detail, the touch screen is integrated with the FFS mode liquid crystal panel, And touch sensing are performed as an example.

FIG. 3 is a view illustrating a display device including a touch screen according to an embodiment of the present invention, and FIG. 4 is a view illustrating a drive IC according to an embodiment of the present invention.

3, a touch screen integrated display device according to an exemplary embodiment of the present invention includes a display touch panel 100, a driver integrated circuit (IC) 200, a touch integrated circuit (IC) 300, and a lookup table 310 , Look-up table (LUT)). Although not shown in the drawing, the touch screen integrated display device according to the embodiment of the present invention includes a back light unit (not shown) for supplying light to the display touch panel 100, a driving power source for driving backlight driver circuits And a power supply unit (not shown).

The display touch panel 100 includes an upper substrate (color filter array substrate), a lower substrate (TFT array substrate), and a liquid crystal layer interposed between the upper substrate and the lower substrate. The display touch panel 100 includes a plurality of gate lines and data lines formed to cross each other, and a plurality of pixels are defined by the plurality of gate lines and data lines.

A plurality of pixels are arranged in a matrix, and one pixel may be composed of three sub-pixels (RGB) or four sub-pixels (RGBW). In each sub-pixel, a switching TFT, a storage capacitor, a pixel electrode, and a common electrode are formed. At this time, the common electrode may be formed in one pixel unit or in a group unit composed of a plurality of pixels.

Here, when an image is displayed using a vertical electric field such as a TN (Twisted Nematic) mode and VA (Vertical Alignment) mode, a common electrode is formed on the upper substrate. Meanwhile, when an image is displayed using a horizontal electric field or a fringe field, such as an IPS (In Plane Switching) mode or an FFS (Fringe Field Switching) mode, a common electrode is formed on the lower substrate.

The plurality of pixels controls the arrangement of the liquid crystal in accordance with the data voltage supplied to the pixel electrode and the electric field formed by the common voltage Vcom supplied to the common electrode and adjusts the arrangement of the liquid crystal, The image is displayed by adjusting the transmittance.

A predetermined number of pixels (for example, 64 pixels x 64 pixels) are formed as a single touch group 120, and a plurality of touch groups 120 are formed as a touch screen. At this time, a common electrode is formed for each touch group 120. The common electrode of each touch group 120 is connected to the touch IC 300 through a separate touch line (not shown).

The display touch panel 100 is formed by integrating a touch screen with a pixel for display and a touch screen for touch detection in an in-cell touch manner. Therefore, the display and the touch sensing are temporally divided and driven.

In the display period, a data voltage corresponding to the video data is supplied to the pixel electrodes of each pixel, and a common voltage is supplied to the common electrodes formed in units of the touch blocks 120 to display an image. In the non-display period, the common electrode of the touch block 120 is driven by the touch electrode to sense the user's touch.

4, the driver IC 200 includes a timing controller 210, a gate driver 220, a data driver 230, and a touch data compensator 240, .

When the display touch panel 100 is manufactured in a small size and applied to a mobile device, the timing controller 210, the gate driver 220, the data driver 230, and the touch data correcting unit 240 are integrated into one chip (single chip).

Meanwhile, when the liquid crystal display device is manufactured in a medium size or more and is applied to a monitor or a TV, the gate driver 220 may be directly formed on a substrate of a liquid crystal panel by an ASG (Amorphous Silicon Gate) method or a GIP . In addition, the timing controller 210, the data driver 230, and the touch data correction unit 240 may be formed as separate chips, or some components may be implemented as a single chip.

The timing controller 210 aligns the input video signal DATA, converts the input video signal DATA into RGB image data in a frame unit, and supplies the converted video data to the data driver 230.

The timing controller 210 uses the input timing signal TS to generate a gate control signal GCS for controlling the gate driver 220 and a data control signal DCS for controlling the data driver 230 . The timing signal includes a vertical synchronization signal Vsync, a horizontal synchronization signal Hsync, and a clock signal CLK.

Supplies the gate control signal GCS to the gate driver 220 and supplies the data control signal DCS to the data driver 230. [

The data control signal DCS includes a source start pulse (SSP), a source sampling clock (SSC), a source output enable (SOE) and a polarity (POL) .

The gate control signal GCS may include a gate start pulse (GSP), a gate shift clock (GSC), and a gate output enable (GOE).

The gate driver 220 generates a scan signal (gate drive signal) for driving the TFT formed on the pixels of the display touch panel 100 based on the gate control signal GCS supplied from the timing controller 210. And sequentially supplies the generated scan signal to the gate lines formed on the display touch panel 100 to drive the TFTs of the pixels.

The data driver 230 converts the digital image data R, G, B supplied from the timing controller 210 into an analog data voltage (data signal) using a gamma voltage GMA. The data driver 230 supplies the analog data voltage to the plurality of pixels through the data lines of the panel 100 based on the data control signal DCS from the timing controller 210. [ The data driver 230 generates a common voltage Vcom and supplies the common voltage Vcom to the plurality of touch blocks 120 to display an image.

As described above, a malfunction may occur in the touch sensing due to a change in the capacitance of a pixel due to a change in the screen. In the present invention, the occurrence of an auto-touch failure is prevented by compensating for a change in capacitance of pixels due to a change in the screen.

5 to 9 are views illustrating a method of driving a display device including a touch screen according to an embodiment of the present invention. Hereinafter, the touch data correcting unit 240 and the touch IC 300 will be described with reference to FIGS. 5 to 9 and a driving method of a display device including a touch screen according to an embodiment of the present invention.

As shown in FIGS. 5 and 6, the touch data correcting unit 240 analyzes the image data of one frame unit inputted from the data driver 230. Analyze image data by touch block by analyzing image data.

The electrostatic capacity can be changed in accordance with the change of the image data of each touch block. Therefore, the electrostatic capacitance for each touch block is calculated based on the image data of the sub pixels, and the electrostatic capacitance deviation between the touch blocks is calculated. At this time, the average capacitance of each touch block 120 can be calculated by dividing the sum of capacitances according to image data of the sub-pixels constituting the individual touch block 120 by the number of sub-pixels.

Then, the correcting capacity deviation data for each touch block is transmitted to the touch IC 300. [

Here, a plurality of pixels constituting one touch block 120 share one common electrode to display an image. In the non-display period, the common electrode of each touch block 120 functions as a touch electrode to sense the touch, so that the touch data correction unit 240 calculates an average touch data correction value for each touch block.

As another example of the present invention, the touch data correcting unit 240 analyzes the image data of one frame unit inputted from the data driver 230 to calculate the average brightness for each touch block 120. [ At this time, the average brightness of each touch block 120 can be calculated by adding the brightness values of the sub-pixels constituting the individual touch block 120 and then dividing the brightness value by the number of the sub-pixels.

Then, the electrostatic capacitance for each touch block and the electrostatic capacitance deviation between the touch blocks are calculated based on the average brightness for each touch block, and the corrected capacitance deviation data for each touch block is transmitted to the touch IC 300. [

The touch IC 300 supplies a touch driving signal to each of a plurality of common electrodes through a touch line (not shown), and detects a change in capacitance formed in each touch block 120. The touch block 120 having the finger touch of the user in the non-display period (touch sensing period) generates a change in capacitance, and the touch IC 300 detects the difference in capacitance by the touch blocks 120, Sensing presence and position of touch.

Here, the capacitance data calculated for each touch block 120 can be transmitted and received between the display period in which the image is displayed and the non-display period in which the touch is sensed, and transmission and reception of the capacitance data calculated for each touch block 120 and It can be flexibly adjusted so as not to be disturbed by transmission of data for display of a screen and transmission of touch signals for touch sensing.

5 to 7, the capacitance data for each touch block according to the analysis of image data is input to the touch IC 300 in the touch data correction unit 240, The electrostatic capacitance variation of the touch block due to the screen change is compensated based on the individual capacitance variation data.

At this time, the touch correction data based on the block-by-block capacitance deviation data is loaded in the lookup table 310, and the touch correction data is reflected in the sensed touch raw data to compensate the touch error value according to the screen change . Thus, an auto-touch failure due to a change in luminance of the screen is prevented from occurring.

Referring to FIGS. 7 and 8, the touch correction data according to the capacitance variation of the touch blocks is mapped to the lookup table 310, and the touch IC 300 stores the touch correction data corresponding to the capacitance variation for each touch block Up table (310).

As shown in FIG. 9, the touch IC 300 reflects the touch correction data corresponding to the capacitance variation of each touch block in the sensed touch row data to compensate for the touch error of the touch blocks according to the screen change. Accordingly, since the touch blocks display different images, it is possible to improve the defective auto touch which may occur in the capacitance displacement driving method.

Here, the touch correction data according to the capacitance variation of the touch blocks mapped to the lookup table 310 are prepared in advance and are generated by measuring the variation of the capacitance while changing the image between the touch blocks.

Specifically, the capacitance variation between the touch blocks is measured while one touch block is fixed to a black image (0 gray) while the other touch block is changed from a black image (0 gray) to a white image (255 gray). Thereafter, the touch correction data is generated according to the capacitance variation between the measured touch blocks and is mapped to the lookup table 310.

On the other hand, as another example, the electrostatic capacitance deviation per touch block is calculated by analyzing based on the luminance information of sub pixels per touch block, and the touch correction data is generated based on the electrostatic capacitance deviation.

Thereafter, the touch correction data is reflected on the sensed touch row data to compensate for the touch error caused by the screen change. Accordingly, since the touch blocks display different images, it is possible to improve the defective auto touch which may occur in the capacitance displacement driving method.

Here, when the driver IC 200 and the touch IC 300 are formed as separate chips, a separate communication protocol for data transmission between the driver IC 200 and the touch IC 300 is provided. On the other hand, when the driver IC 200 and the touch IC 300 are constituted by a single chip, it is possible to reduce hassle of hardware design and communication protocol design.

FIG. 10 is a diagram showing that the touch error is improved by compensating the touch data. FIG.

Referring to FIG. 10, various test patterns are automatically changed to show a result of applying touch correction data for each touch block in a random image.

In the case of applying the above-described touch correction data, it can be confirmed that a touch error does not occur in the capacitance displacement driving method even if adjacent touch blocks display different screens. On the other hand, when the touch correction data according to the present invention is not applied, it is possible to confirm that a touch error occurs due to a deviation of the capacitance due to the screen change exceeding the touch judgment criterion when a different screen is displayed on adjacent touch pixels.

The lookup table 310 refers to the touch correction data corresponding to the capacitance variation data for each touch block input to the touch IC 300 to compensate for the change amount of the capacitance unexpectedly changed by the screen change, It is possible to prevent the occurrence of a touch error of the touch sensing function and improve the touch sensing performance.

As the touch sensitivity increases, the touch error data due to screen switching also increases in proportion to increase in touch sensitivity. On the other hand, the touch screen integrated display device and the driving method thereof according to the embodiment of the present invention can prevent the touch failure due to the auto touch while increasing the touch sensitivity.

In manufacturing a display device, a touch failure that may occur due to a production deviation may occur. However, rework of a product that has been mass-produced has many limitations, and there has been a restriction in improving the touch failure.

In contrast, the touch screen integrated display device and the driving method thereof according to the embodiment of the present invention can compensate the capacitance variation according to the mass production deviation and improve the touch defect due to the mass production deviation. Therefore, it is possible to increase the mass productivity of the touch screen integrated display device and reduce the defective touch ratio, thereby enhancing the product competitiveness.

It will be understood by those skilled in the art that the present invention can be embodied in other specific forms without departing from the spirit or essential characteristics thereof.

It is therefore to be understood that the above-described embodiments are illustrative in all aspects and not restrictive. The scope of the present invention is defined by the appended claims rather than the detailed description and all changes or modifications derived from the meaning and scope of the claims and their equivalents are to be construed as being included within the scope of the present invention do.

100: Display touch panel 200: Driver IC
210: timing controller 220: gate driver
230: Data driver 240: Touch data correction unit
300: touch IC 310: lookup table

Claims (10)

A display touch panel in which a touch screen is formed in a pixel;
A driver IC (Integrated Circuit) for supplying a data voltage according to image data to pixels of the display touch panel and analyzing the image data to calculate a capacitance variation of the touch blocks composed of a certain number of pixels; And
And a touch IC which supplies a touch driving signal to the touch blocks and senses a touch by compensating for a variation in capacitance between the touch blocks. The method according to claim 1,
The touch IC includes:
And compensates the electrostatic capacitance change amount of the touch block based on a deviation of capacitance between the touch blocks generated by the touch blocks having different screens. The method according to claim 1,
The touch IC includes:
And compensates the electrostatic capacitance change amount of the touch block according to the screen change by reflecting a deviation of capacitance between the touch blocks in the sensed touch row data. The method according to claim 1,
The touch IC includes:
Wherein the touch sensing unit senses a touch by reflecting a capacitance variation of each touch block due to a difference in brightness between the touch blocks. The method according to claim 1,
The touch IC includes:
And sensing the touch by reflecting the capacitance deviation between the touch blocks to the sensed touch row data. The method according to claim 1,
Further comprising a look-up table to which touch correction data according to a capacitance variation between the touch blocks are mapped,
Wherein the touch IC compensates for a capacitance change amount of a touch block according to a screen change by referring to the touch correction data mapped to the lookup table. Calculating capacitance variation between the touch blocks by analyzing image data of each frame;
Generating touch correction data for each touch block based on a capacitance variation between the touch blocks; And
And compensating a capacitance change amount of the touch blocks according to a screen change based on the touch correction data for each touch block,
And sensing the touch by reflecting the touch correction data for each touch block to the sensed touch low data. 8. The method of claim 7,
And sensing the touch by reflecting the touch correction data corresponding to the capacitance deviation between the touch blocks to the touch determination reference data. 8. The method of claim 7,
The touch correction data corresponding to the capacitance variation between the touch blocks is mapped to the lookup table,
And compensating for a capacitance change amount of the touch block in accordance with the change of the screen with reference to the touch correction data. 8. The method of claim 7,
Wherein the touch block is turned off by reflecting the capacitance variation between the touch blocks generated due to the display of the different images by the touch blocks in the touch presence / absence determination.

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