KR101407303B1 - Touch Panel Apparatus - Google Patents

Abstract

The touch panel device according to the present invention is intended to reduce the production cost and improve the detection accuracy of the touch position.

In order to achieve the above-described object, a color filter substrate having a color filter side common electrode, an array substrate having pixel electrodes, a liquid crystal interposed between the color filter substrate and the array substrate, a gate driver for driving the liquid crystal, A touch panel device having a data driver, comprising: three or more current measuring means for measuring a current value flowing through a common electrode on a color filter side when a contact object contacts the surface of the panel; And the current measuring means measures the current value during the blanking period in which the gate driver and the data driver are not driven. In addition, the blanking period may be set longer than usual.

The touch panel device according to the present invention integrates the liquid crystal panel and the touch panel to reduce the cost and improve the precision of detecting the position of the touch position.

Touch panel device, blanking period, current measuring means

Description

[0001] The present invention relates to a touch panel device,

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a touch panel, and more particularly to a touch panel employing a liquid crystal display device.

2. Description of the Related Art Conventionally, a touch panel has been developed which outputs a current signal output according to a position when a contact object such as a finger touches an image surface on which image information is output. (Patent Document 1: JP-A-5-324203)

For example, in a conventional capacitive touch panel, a second transparent substrate for preventing glare by a transparent adhesive material is attached to a touch surface side of a first transparent substrate provided with a transparent conductive film for touch position detection Thereby preventing damage to the transparent conductive film and realizing a touch panel with a simple structure, thereby improving the mechanical strength.

However, in such a capacitive touch panel, since the touch panel itself must be adhered to the front surface of the display on which the screen is implemented, the manufacturing cost is increased and the thickness of the device itself is increased, There was a problem that it was difficult.

In order to solve such a problem, a touch panel device has been proposed in which the display and the touch panel share an electrode plate, thereby reducing the production cost and reducing the thickness of the device itself. (Patent Document 2: Japanese Patent Application Laid-Open No. 2003-99192)

Figs. 8A and 8B are diagrams showing a configuration of a conventional touch panel device described in Patent Document 2. Fig.

8A, the conventional touch panel device has a structure in which a common transparent electrode 109, a liquid crystal 110, and a display transparent electrode 111 are sequentially stacked between two transparent insulating plates 107 and 108,

In order to sense the positional coordinates of the contact portion on the transparent insulating plate 107 disposed on the common transparent electrode 109 side on which the touching object is in contact, as shown in Fig. 8B, And current detectors (101 to 104) for detecting a current flowing between the common transparent electrodes (109) with a contact material and a transparent insulating plate interposed therebetween at four corners of the common transparent electrode (109)

The change of the current value due to the contact of the contact object with the contact portion on the transparent insulating plate 107 is measured by the current detector provided at the four corners and the current signal from the current detector showing the measured current value And a signal processing circuit 106 for calculating the positional coordinates of the contact portion by means of the first to fourth switches S1 to S4.

However, in the conventional touch panel device disclosed in Patent Document 2,

There is a problem that an error occurs in the detection of the touch position due to the influence of the coupling of the signal line or the gate line and the contents of the touch input by the user may be misrecognized.

The reason for this will be described with reference to Figs. 9 and 10 which are timing charts of waveforms of dot inversion driving.

For reference, Vcom is a common voltage, Vgh is a gate ON voltage, Vgl is a gate OFF voltage, and Vsig is a data voltage.

As shown in Fig. 9, theoretically, the common voltage Vcom is constant, there is no fluctuation, and there is almost no current flow.

However, in reality, as shown in Fig. 10, the common voltage Vcom fluctuates due to the influence of the coupling of the signal line and the gate line, and the current always flows in and out. Therefore, even if the current measurement for touch position detection is performed in this state, errors are likely to occur, and it becomes difficult to perform the touch position detection with high precision.

SUMMARY OF THE INVENTION The present invention has been made in order to solve such a problem,

It is an object of the present invention to provide a touch panel device which can integrate a liquid crystal panel and a touch panel to reduce the cost and improve the accuracy of detecting the position of the touch position.

According to an aspect of the present invention, there is provided a touch panel device comprising:

A liquid crystal display device comprising: a color filter substrate having a common electrode; an array substrate having pixel electrodes; a liquid crystal interposed between the color filter substrate and the array substrate; and a touch panel having driving means for driving the liquid crystal, Device,

Current measuring means for measuring a current value flowing through the common electrode at a plurality of three or more places when a contact object contacts the surface of the panel; And a position coordinate calculation means for calculating a position coordinate,

The current measuring means measures the electric current value during a blanking period in which the electric driving means is not driven.

In the touch panel device according to the present invention,

A touch panel including a color filter substrate having a common electrode, an array substrate having pixel electrodes, liquid crystal interposed between the color filter substrate and the array substrate, and driving means for driving the liquid crystal, ) Device,

A plurality of, preferably three or more, current measuring means for measuring a current flowing through the common electrode when the contact surface of the panel is in contact with the surface of the panel; And position coordinate calculation means for calculating the position coordinate of the object,

Wherein the current measuring means performs the measurement of the current value during a blanking period in which the driving means is not driven,

By integrating the liquid crystal panel and the touch panel, the cost can be reduced and the precision of the position detection of the touch position can be improved.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, embodiments of the present invention will be described in detail with reference to the accompanying drawings.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a view showing a basic configuration of a touch panel device according to a first embodiment of the present invention; FIG.

1, a touch panel device according to a first embodiment of the present invention includes a liquid crystal panel 1 having a pixel matrix, a liquid crystal panel 1 for driving a gate line GL of the liquid crystal panel 1, A data driver 3 which is a drive circuit for driving the data line DL of the liquid crystal panel 1 and a timing controller 4 for controlling the gate driver and the data driver, Respectively.

Further, when a contact object such as a finger or a touch pen touches the display area (touch surface) of the liquid crystal panel 1,

In the case of a capacitive touch panel device, the electrostatic capacity is changed. In the case of a resistive touch panel device, the resistance value is changed.

A signal processing circuit 5 for calculating the position coordinates of the touch position of the touching object in accordance with the change of the current value based on the change, and a signal processing circuit 5 for extracting the contents corresponding to the position coordinates from the storage device 7 such as an internal memory And a control circuit 6 for displaying a character or an image on the liquid crystal panel 1 based on the extracted contents or performing necessary processing to output a signal to another apparatus.

The liquid crystal panel 1 has a pixel matrix composed of liquid crystal cells formed in each pixel region defined by the intersection of the gate line GL and the data line DL.

The liquid crystal cell includes a liquid crystal cell Clc for adjusting the amount of light transmitted by an image data signal and a thin film transistor (TFT) serving as a liquid crystal driving switching element for driving a liquid crystal capacitor.

The thin film transistor TFT is responsive to the scan signal of the gate line GL so that the data signal of the data line is charged and held in the liquid crystal cell Clc.

The liquid crystal cell Clc changes the arrangement state of the liquid crystal by the data signal to adjust the light transmittance to realize the gradation.

The gate driver 2 sequentially supplies a scan signal to the gate line GL in response to a control signal from the timing controller 4. [

The data driver 3 converts the digital image data from the timing controller 4 into analog data signals and supplies them to the data lines.

The timing controller 4 supplies a control signal for controlling the gate driver 2 and the data driver 3 and supplies digital image data to the data driver so as to control the display area of the liquid crystal panel 1, So that an image is displayed.

Next, the liquid crystal panel 1 will be described with reference to Fig. 2 which is an exploded perspective view of the liquid crystal panel.

2, the liquid crystal panel 1 is constituted by a color filter substrate 10 and an array substrate 20 to which liquid crystal 9 is bonded.

The color filter substrate 10 is constituted by sequentially forming a black matrix 12, a color filter 13 and a color filter side common electrode 14 on a color filter side glass substrate 11 composed of a transparent insulating plate .

The black matrix 12 is formed in the form of a matrix on the color filter side glass substrate 11 so that the region of the color filter side glass substrate 11 is divided into a plurality of cell regions in which the color filter 13 is formed, It prevents light interference and reflection of external light.

The color filter 13 is divided into red (R), green (G), and blue (B) in a cell region divided by a black matrix to transmit red, green, and blue light, respectively.

The color filter side common electrode 14 is a transparent electrically conductive layer formed on the front surface of the color filter 13 and supplies a common voltage Vcom as a reference for driving the liquid crystal 9. [

An overcoat layer (not shown) may be additionally formed between the color filter 13 and the color filter side common electrode 14 in order to planarize the color filter 13.

The array substrate 20 includes a plurality of gate lines GL and data lines DL formed vertically and horizontally on the array side glass substrate 21 constituted by a transparent insulating plate and a plurality of gate lines GL and data lines DL crossing the gate lines GL and data lines A thin film transistor (TFT) formed for each cell region defined by the pixel region, and an array pixel electrode 22. [

The thin film transistor TFT supplies a data signal from the data line to the array pixel electrode 22 in response to a gate signal from the gate line GL.

The array pixel electrode 22 made of a transparent electrically conductive layer drives the liquid crystal 9 through a data signal from the thin film transistor TFT.

The liquid crystal 9 having a dielectric anisotropy realizes gradation by rotating along the electric field formed by the data signal of the array pixel electrode 22 and the common voltage Vcom of the common electrode 14 to adjust the light transmittance.

The liquid crystal panel 1 includes an alignment film for initial alignment of the liquid crystal 9 and a spacer for maintaining a constant cell gap between the color filter substrate 10 and the array substrate 20 ).

The basic structure of the liquid crystal panel 1 has been described above and the touch panel device according to the present invention is constructed by using the liquid crystal panel 1 described above to display characters and images on the liquid crystal panel 1 At the same time, it is configured to detect the position coordinates of the touch position (contact portion) of the color filter substrate 14 disposed on the color filter side common electrode side where the contact area such as the finger or the touch pen touches the display area of the liquid crystal panel 1 do.

3 is a view showing an example of a panel configuration of a touch panel device employing the above-described liquid crystal panel 1, and Fig. 4 is a cross-sectional view taken along line A-A 'of Fig.

3 and 4, the liquid crystal panel 1 includes a display area 30 composed of a pixel matrix, and a black matrix frame 30 having a predetermined line width 31a provided around the display area 30, (31).

An X tab 32 for electrically connecting the data driver 3 and the liquid crystal panel 1 is provided on the liquid crystal panel 1. [ The X-tap 32 is provided with a data line input section 33 into which a data signal supplied from the data line is input.

A Y-tab 34 for electrically connecting the gate driver 2 and the liquid crystal panel 1 is provided on the liquid crystal panel 1. [ The Y tab 34 is provided with a gate line input section 35 to which a gate signal supplied from the gate line GL is input.

A common electrode input portion 36 for giving a common voltage Vcom from the power source (8 in Fig. 1) to the color filter side common electrode 14 is connected to the color filter side common electrode 14, Three corners of the four corners.

The junctions 37 for electrically connecting the array side common electrodes 23 and the color filter side common electrodes 14 are provided at three corners provided with the common electrode input portions (see the sectional view of FIG. 4). ).

As described above, since the configuration of Fig. 3 is a tab, the X tab 32 and the Y tab 34 are provided on the array substrate, respectively. Therefore, the supply of the common voltage Vcom to the color filter side common electrode 14 is often performed through three points from the three common electrode input units 36 as shown in Fig. 3. In this case, And the voltage is not supplied to the lower right corner of the region.

If a common voltage is supplied to the common electrode on the color filter side in more than three places, the X tab 32 and the Y tab 34 may be provided on the sides provided with the common voltage.

 On the other hand, here, the tab is a case in which a signal is supplied to one side of the liquid crystal panel

For example, a case where a signal is input to both sides of the liquid crystal panel, such as a case where the signal input on the Y side is both, is referred to as both tabs.

Next, the operation of the touch panel device of the present invention configured as described above will be described.

5 is a view for explaining the driving timing in the column direction in the touch panel device of the present invention.

The liquid crystal panel 1 having the configuration of Fig. 3 is driven at 60 Hz in general.

Taking the case of a VGA (Video Graphics Array) as an example, the number of pixels of VGA is 640 x 3 rows in the column direction and 480 rows in the row direction.

The timing shown in FIG. 5 will be described with reference to VGA. The active period is a period in which gate signals are sequentially supplied to 480 rows, that is, 480 rows, and the blanking period is several tens, And the gate signal is sequentially supplied to the line.

On the other hand, the active period is a period in which a data line and a gate line are driven so that a character or an image is displayed in the display area 30 of the liquid crystal panel 1,

The blanking period is a period during which both the data line and the gate line are not driven.

The active period and the blanking period are determined depending on the specification of the product, and thus they are somewhat different for each product.

At this time, during the blanking period, since neither the data line nor the gate line is driven, the voltage becomes constant, and the common voltage Vcom is also constant regardless of the coupling of the data line and the gate line.

Taking such a point into consideration, the touch panel device of the present invention performs the position measurement of the touch position in the blanking period, thereby improving the accuracy of current detection for position detection, thereby improving the accuracy of position detection.

As the current measuring method, the color filter side common electrode 14, the color filter side common electrode 14 and the junction portion 37 of the array side common electrode 23 are connected to a sensor for detecting the position of the touch panel, It is used as a current measuring means.

In the electrostatic capacitance type touch panel, electricity flows to the color filter side common electrode 14 when a touching object such as a finger or a touch pen touches the surface of the panel. Therefore, the electric current flows in three corners of the liquid crystal panel 1 And then outputs the signal to the signal processing circuit 5. The signal processing circuit 5 outputs the signal to the signal processing circuit 5,

Since the magnitudes of the three current values thus measured are proportional to the distance to the touch position, the signal processing circuit 5 calculates the position coordinates of the touch position from the magnitude of the measured three current values.

The control circuit 6 extracts processing contents set in advance for each display screen from the storage device 7 in accordance with the position coordinates of the calculated touch position,

Displays a character or an image on the display panel 1 in accordance with the extracted information, or outputs a result obtained by performing necessary processing to another apparatus.

On the other hand, in the configuration of Fig. 3, the junction 37 is provided outside the three corners of the display region, and three current values are measurable, but the present invention is not limited thereto,

For example, the junction 37 may be provided at the four corners of the liquid crystal panel 1, the current value may be measured at the four junctions, and the position detection may be performed using the four measured current values. In this case The accuracy is further improved.

As described above, the touch panel device according to the first embodiment of the present invention performs the current measurement for position detection during the blanking period in which the common voltage Vcom is constant, so that the influence of the coupling of the data line and the gate line It is possible to improve the accuracy of the current detection for the position detection and thereby improve the accuracy of the position detection.

In addition, a touch panel device according to the first embodiment of the present invention includes:

The color filter side common electrode provided on the liquid crystal panel can be used as current measuring means for touch position detection to share the electrode plate of the liquid crystal monitor and the touch panel, panel can be integrated, so that the thickness of the touch panel device and the manufacturing cost can be reduced.

Next, a touch panel device according to a second embodiment of the present invention will be described.

In the touch panel device according to the second embodiment of the present invention, it is desirable to keep the blanking period as long as possible in order to improve the position detection accuracy.

FIG. 6A is a timing chart showing a blanking period in the touch panel device according to the first embodiment of the present invention, and FIG. 6B is a timing chart showing a blanking period in the touch panel device according to the second embodiment of the present invention It is a timing chart.

6A and 6B, it can be seen that the blanking period of FIG. 6B is longer than the blanking period of FIG. 6A, so that the active period of FIG. 6B is shorter than the active period of FIG. 6A.

More specifically, since the liquid crystal panel 1 is driven at 60 Hz in general, the ratio of the active period and the blanking period in one period is changed.

Here, as described above, since the active period and the blanking period are arbitrarily set to specifications of the product,

In the design stage, it will be possible to easily design the blanking period to be long. Usually, the ratio of the active period to the blanking period is about 50: 1. In the touch panel device according to the second exemplary embodiment of the present invention, the ratio of the active period to the blanking period is set to about 499: 10 to 1: 2.

As described above, since the blanking period is set to be long in the touch panel device according to the second embodiment of the present invention, the detection period can be shortened, and the detection accuracy can be improved.

For example, in the touch panel device according to the first embodiment of the present invention, since the liquid crystal panel 1 is driven at 60 Hz, the position detection period is also set to a cycle of 60 Hz,

If the length of the blanking period is set equal to the length of the active period, the position detection period can be increased to 120 Hz. It is also possible to increase the detection period by simply making the blanking period constant and increasing the driving frequency.

The other structures and operations of the touch panel device according to the second embodiment of the present invention are the same as those of the touch panel device according to the first embodiment of the present invention.

As described above, the touch panel device according to the second embodiment of the present invention can obtain the same effect as the touch panel device according to the first embodiment of the present invention described above, and simultaneously sets the blanking period to be longer, The detection accuracy can be further improved.

Next, a touch panel device according to a third embodiment of the present invention will be described.

In the touch panel device according to the first embodiment of the present invention, since the liquid crystal panel 1 is driven at 60 Hz, the position detection is performed at a cycle of 60 Hz,

The touch panel device according to the third embodiment of the present invention performs field sequential driving of 180 Hz.

FIG. 7A is a timing chart showing a blanking period in the touch panel device according to the first embodiment of the present invention, and FIG. 7B is a timing chart showing a blanking period of the touch panel device according to the third embodiment of the present invention .

7B, in the touch panel device according to the third embodiment of the present invention, the liquid crystal panel 1 is driven at 180 Hz, and the ratio in one cycle to the active period of the blanking period in Fig. Is equal to, but is not limited to, the ratio in one cycle to the active period of the blanking period in Fig. 6A,

The ratio in one cycle to the active period of the blanking period can be increased and the blanking period can be set longer to improve the position detection precision.

The touch panel device according to the third exemplary embodiment of the present invention drives the liquid crystal panel 1 at a cycle of 180 Hz, thereby performing position detection at a cycle of 180 Hz, thereby further improving detection accuracy.

Further, by driving at 360 Hz, the position detection accuracy can be further improved.

On the other hand, the driving period is not limited to 180 Hz and 360 Hz, and can be set to any desired period.

Similarly, the other structures and operations of the touch panel device according to the third embodiment of the present invention are the same as those of the touch panel device according to the first embodiment of the present invention, and therefore, the above description will be substituted.

As described above, the touch panel device according to the third embodiment of the present invention can obtain the same effects as those of the touch panel device according to the first embodiment of the present invention described above, sets the blanking period to be longer, The detection accuracy can be further improved.

While the present invention has been described in connection with what is presently considered to be the most practical and preferred embodiment, it is to be understood that the invention is not limited to the disclosed embodiments, but, on the contrary, is intended to cover various modifications and equivalent arrangements included within the spirit and scope of the appended claims. As will be apparent to those of ordinary skill in the art.

1 is an explanatory view showing a basic configuration of a touch panel device according to a first embodiment of the present invention;

2 is an exploded perspective view showing a configuration of a liquid crystal panel that can be employed in a touch panel device according to a first embodiment of the present invention.

3 is a plan view showing an example of a panel configuration in a touch panel device according to the first embodiment of the present invention.

4 is a sectional view taken along line A-A 'in Fig. 3;

FIGS. 5, 6A and 7A are timing charts showing operations of a touch panel device according to the first embodiment of the present invention. FIG.

6B is a timing chart showing the operation of a touch panel device according to the second embodiment of the present invention.

7B is a timing chart showing the operation of the touch panel device according to the third embodiment of the present invention.

8 is an explanatory view showing a configuration of a conventional touch panel device.

9 is a diagram showing a theoretical waveform of the dot inversion driving.

10 is a diagram showing an actual waveform of a dot inversion driving;

Description of the Related Art

1: liquid crystal panel 2: gate driver

3: Data driver 4: Timing controller

5: Signal processing circuit 6: Control circuit

7: memory device 8: power source

9: liquid crystal 10: color filter substrate

11: Color filter side glass substrate 12: Black matrix

13: Color filter 14: Color filter side common electrode

20: array substrate 21: array-side glass substrate

22: array pixel electrode 30: display area

31: black matrix frame portion 31a: line width

32: X tab 34: Y tab

33: data line input section 35: gate line input section

36: common electrode input unit 37:

DL: Data line GL: Gate line

TFT: Thin film transistor

Claims (4)

A color filter substrate having a common electrode; An array substrate having a pixel electrode and a common electrode; A liquid crystal interposed between the color filter substrate and the array substrate; A driving unit for driving the liquid crystal; Three or more current measuring units for measuring a current flowing in a junction connecting the common electrode of the color filter substrate and the common electrode of the array substrate during a blanking period during which the driving unit is not driven; And And a position coordinate calculation unit for calculating position coordinates of the measured current value. The method according to claim 1, Wherein the blanking period is set so that the ratio of the active period in which the driving unit is driven and the blanking period is in the range of 1: 1 to 1: 2. The method according to claim 1, Wherein the driving frequency of the liquid crystal is set to a frequency higher than 60 Hz, and the current measuring unit measures the current value at a frequency faster than 60 Hz. The method according to claim 1, Wherein a common voltage having a constant voltage is supplied to the common electrode during the blanking period.

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