KR20110063044A - Touch panel integrated liquid crystal display - Google Patents

Abstract

PURPOSE: A liquid crystal display device for an integrated type touch panel is provided to minimize the total thickness and weight even if the touch panel is added so that the panel can be design slim. CONSTITUTION: A liquid crystal display device for an integrated type touch panel includes a thin film transistor array substrate(110) and a color filter array substrate(120), a plurality of spacer(140), a liquid crystal layer(130), a plurality of lead electrode(150), a plurality of second lead electrode(160), and a compensation electrode(300). The thin film transistor array substrate and the color filter array substrate are facing each other. The plurality of spacer is arranged between the thin film transistor array substrate and the color filter array substrate to maintain an interval between the thin film transistor array substrate and the color filter array substrate.

Description

Touch panel integrated liquid crystal display

The present invention relates to a touch panel integrated liquid crystal display device capable of reducing overall weight and thickness.

In recent years, as the information age has entered, the display field for visually expressing electrical information signals has been rapidly developed, and various flat panel display devices having excellent performance of thinning, light weight, and low power consumption have been developed. Flat Display Device has been developed to quickly replace the existing Cathode Ray Tube (CRT).

Specific examples of such a flat panel display device include a liquid crystal display device (LCD), a plasma display panel device (PDP), a field emission display device (FED), and an electroluminescent display device. Electro luminescence Display Device (ELD) and Electro-Wetting Display (EWD). Such flat panel displays essentially include a display panel that implements an image by bonding a pair of insulating substrates to each other with a unique light emitting or polarizing material layer interposed therebetween. Among them, the liquid crystal display device displays an image by using the light transmittance of the liquid crystal that is adjusted according to the electric field, and has the advantages of miniaturization, thinning, and low power consumption, and is used for notebook computers, office automation devices, and audio / video devices. It is widely used.

In general, personal computers, portable communication devices, and other personal information processing devices use various input devices such as a keyboard, a mouse, and a digitizer to configure an interface with a user. In recent years, as the development of mobile communication equipment has been expanded, input devices such as a keyboard and a mouse have difficulty in increasing the completeness of a product, and thus, development of an input device having high portability, which can be used in a simpler method, continues. Accordingly, a touch panel has been proposed in which a user directly touches a screen with a hand or a pen to input information.

The touch panel is simple, has less malfunctions, can be inputted without any other input device, and thus is easy to carry, and the user can easily recognize how to use it. In particular, when an icon or a keyboard displayed on the screen of the display device is selected, a flat panel display device with a touch panel is added to a portable information processing device such as a personal computer or a mobile phone so that the corresponding icon or keyboard can be selected to input information. Frequently applied. As a flat panel display device to which such a touch panel is added, a touch panel attached liquid crystal display device to which a touch panel and a liquid crystal panel are attached has been proposed.

1 is a cross-sectional view showing a touch panel attached liquid crystal display device according to the prior art. 2A is a cross-sectional view illustrating an example of the touch panel illustrated in FIG. 1, and FIG. 2B is a cross-sectional view illustrating another example of the touch panel illustrated in FIG. 1.

In the touch panel attached liquid crystal display device according to the related art, as illustrated in FIG. 1, a liquid crystal panel 10 displaying an image, a backlight unit 20 irradiating light to the liquid crystal panel, a touch sensing touch or not It comprises a panel 30, and an adhesive layer 40 for bonding the liquid crystal panel 10 and the touch panel 30.

The liquid crystal panel 10 includes a thin film transistor array substrate 11 (hereinafter referred to as a TFT substrate) and a color filter array substrate 12 (CF substrate) facing each other. ), A spacer (not shown) for maintaining a constant cell gap between the TFT substrate 11 and the CF substrate 12, and a liquid crystal layer 13 filled between the TFT substrate 11 and the CF substrate 12. To form a plurality of pixels.

The TFT substrate 11 includes a gate line and a data line intersecting each other to define a pixel region, a thin film transistor disposed at an intersection of the gate line and the data line, and a pixel electrode disposed corresponding to the pixel region. It is configured to include. Here, the pixel electrode is applied with a pixel voltage corresponding to each pixel, and a common electrode to which a common voltage corresponding to a plurality of pixels is applied, and an electric field for adjusting the direction of the liquid crystal cell of the liquid crystal layer 13 is provided. Form.

The CF substrate 12 includes a black matrix layer disposed to correspond to the outer periphery of the pixel region, a color filter layer corresponding to any one of R, G, and B, and a top portion of the color filter layer disposed corresponding to the pixel region. And an overcoat layer.

The touch panel 30 may form a metal electrode on the upper plate or the lower plate according to a method of detecting a contacted portion, and may determine a contact position as a voltage gradient according to resistance in a state where a DC voltage is applied. type), a capacitive type forming an equipotential on the conductive film and detecting the position of the voltage change of the upper and lower plates due to contact, and the contacted position by reading the LC value induced when the electronic pen contacts the conductive film. Electromagnetic induction (Electro Magnetic type) for detecting the may be provided.

As illustrated in FIG. 2A, the touch panel 30a according to an example may include an insulating substrate 31 such as glass, a first electrode 32 and a first electrode disposed on the rear surface of the insulating substrate 31. And a lead electrode 33 disposed on the rear surface of the electrode 32, a second electrode 34 disposed on the upper surface of the insulating substrate 31, and a potential compensation electrode 35 disposed on the upper surface of the second electrode. . In addition, a protective substrate 36 for protecting the touch panel 30a from external shock is disposed on the potential compensation electrode 35. The touch panel 30a configured as described above has a protective substrate 36 in a state in which a predetermined electric field is formed between the first electrode 32 and the second electrode 34 by applying an alternating voltage to the potential compensation electrode 35. The capacitance between the first electrode 32 and the second electrode 35 is changed by the touch generated on the upper part, and the amount of current reaching the edge of the second electrode 35 is changed by the changed capacitance. The touch is sensed by recognizing the amount of current reaching the edge of the second electrode 35 by using the difference for each touched position.

As another example of the touch panel 30b, as illustrated in FIG. 2B, the X electrode disposed in the first direction on the lower substrate 37a of the insulation, such as glass, and the lower substrate 37a ( 38a), a first insulating layer 39a formed on the front surface of the lower substrate 37a including the X electrode 38a, and Y disposed in a second direction perpendicular to the first direction on the first insulating layer 39a. And a second insulating layer 39b formed on the entire surface of the first insulating layer 39a including the electrode 38b and the Y electrode 38b. In addition, an upper substrate 37b for protecting the touch panel 30a from external shock is disposed on the touch panel 30b. In the touch panel 30b configured as described above, the capacitance generated between the X electrode 38a and the Y electrode 38b varies depending on the touch applied on the upper substrate 37b. The touched position is sensed by recognizing a change in capacitance.

As described above, in the touch panel type liquid crystal display device according to the related art, the liquid crystal panel 10 and the touch panel 30 are separately provided, and the liquid crystal panel 10 and the touch panel 30 are provided through the adhesive layer 40. It is manufactured by bonding. As such, since the liquid crystal panel 10 and the touch panel 30 are provided including respective insulating substrates, there is a limit in reducing the overall thickness and weight of the touch panel attached liquid crystal display device. In addition, since a separate configuration (adhesive layer 40) for bonding the liquid crystal panel 10 and the touch panel 30 is necessarily provided, there is a limit in reducing the bezel, so that it is difficult to design a slim body.

Accordingly, the present invention provides a touch panel integrated liquid crystal display device that can be designed slim because the overall thickness and weight of the device can be minimized even if a touch panel is added.

In order to solve such a problem, the present invention, the thin film transistor array substrate and the color filter array substrate facing each other; A plurality of spacers disposed between the thin film transistor array substrate and the color filter array substrate such that a gap between the thin film transistor array substrate and the color filter array substrate is maintained; A liquid crystal layer filled between the thin film transistor array substrate and the color filter array substrate; A plurality of first lead electrodes spaced at predetermined intervals and disposed on a portion of a rear surface of the color filter array substrate including at least one corresponding spacer among the plurality of spacers; A plurality of second lead electrodes disposed on an upper surface of the thin film transistor array substrate to be in contact with the plurality of first lead electrodes, respectively; And a compensation electrode disposed on an upper surface of the color filter array substrate and configured to apply an alternating voltage to the touch panel.

As described above, the touch panel integrated liquid crystal display device according to the present invention includes a liquid crystal panel provided integrally with the touch panel, and may minimize the overall thickness and weight while having the touch panel. Accordingly, it can be designed to be slim, thereby improving portability.

Hereinafter, a touch panel integrated liquid crystal display according to an exemplary embodiment of the present invention will be described in detail with reference to the accompanying drawings.

3 is a cross-sectional view illustrating a touch panel integrated liquid crystal display device according to an exemplary embodiment of the present invention. FIG. 4 is a plan view corresponding to one pixel of the thin film transistor array substrate shown in FIG. 3, and FIG. 5 is shown in FIG. 3. Is a plan view of the color filter array substrate. 6 is a cross-sectional view taken along line AA ′ of FIG. 5, and FIG. 7 is a cross-sectional view taken along line B-B ′ of FIG. 5.

As shown in FIG. 3, the touch panel integrated liquid crystal display according to an exemplary embodiment of the present invention displays an image by adjusting light transmittance in the direction of the liquid crystal cell, and detects touch. The backlight unit 200 disposed under the 100 to irradiate light to the liquid crystal panel 100, the compensation electrode 300 and the compensation electrode 300 disposed above the liquid crystal panel 100 and to which an AC voltage is applied. It is disposed on the upper portion of the protection panel 400 and the compensation electrode 300 to protect from the external shock is configured to include.

The liquid crystal panel 100 includes a thin film transistor array substrate 110 (hereinafter referred to as a TFT substrate) and a color filter array substrate 120 (hereinafter referred to as a “CF substrate”) that face each other. In order to maintain the gap between the liquid crystal layer 130 and the CF substrate 120 and the TFT substrate 110 filled between the CF substrate 120 and the TFT substrate 110, the CF substrate 120 and A plurality of spacers 140 disposed between the TFT substrates 110 and a plurality of spacers spaced at predetermined intervals and disposed on a portion of the rear surface of the CF substrate 120 including at least one spacer corresponding to the plurality of spacers 140. The first lead electrode 150 and the TFT substrate 110 include a plurality of second lead electrodes 160 disposed to be in contact with the plurality of first lead electrodes 150, respectively.

The backlight unit 200 includes a light source provided with a plurality of light emitting diodes (LEDs) or at least one lamp, a reflector disposed under the light source, and reflects light generated from the light source toward the liquid crystal panel 100. It includes a plurality of light diffusion sheet disposed on the top of the light scattering or diffusing light, and supplies the light generated from the light source to the liquid crystal layer 130 side.

An alternating voltage (AC) is applied to the compensation electrode 300 disposed on the CF substrate 120, so that a first storage capacitor may be disposed between the plurality of first lead electrodes 150 disposed on the rear surface of the CF substrate 120. Storage Capacitor, Cst1) is generated. The touch voltage Vtouch stored in the first storage capacitor Cst1 is changed according to the touch, and the touch sensing may be performed by tracking a position corresponding to the first storage capacitor in which the touch voltage Vtouch is changed. .

Next, the liquid crystal panel 100 will be described next.

As illustrated in FIG. 4, the TFT substrate 110 included in the liquid crystal panel 100 includes a gate line GL, a data line DL, and a gate line intersecting each other so that the pixel region P is defined. A pixel electrode (not shown) connected to the display transistor Td disposed at the intersection of the GL and the data line DL, the table sheet transistor Td, and disposed to correspond to the pixel region P, and the data line (not shown). The second lead electrode LD 160 disposed in parallel with the DL and disposed at an intersection of the lead-out line RL and the gate line GL and the lead-out line RL disposed to cross the gate line GL. It is configured to include a switch transistor (Ts) connected to. In this case, when the liquid crystal panel 100 is driven in the transverse electric field mode in which the direction of the liquid crystal cell included in the liquid crystal layer 130 is controlled by the transverse electric field, the TFT substrate 110 may correspond to the pixel region P. The display device may further include a common electrode (not shown) disposed alternately with the display, and to which a common voltage corresponding to the plurality of pixels is applied.

The display transistor Td is turned on and off according to the gate signal applied through the gate line GL, and when turned on, the display transistor Td outputs the data signal applied through the data line DL to the pixel electrode (not shown). The switch transistor Ts is turned on and off in response to a gate signal applied through the gate line GL, and when turned on, the switch transistor Ts outputs a voltage to the second lead electrode LD and 160 as a readout line RL. .

Next, as illustrated in FIGS. 5 to 7, the CF substrate 120 is disposed to correspond to the outside of the pixel region P on the back surface of the insulating substrate 121 such as glass and the first substrate 121. The black matrix layer 122 corresponds to the pixel region P and at least a portion of the black matrix layer 122 overlaps the black matrix layer 122 and corresponds to any one of R (Red), G (Green), and B (Blue). The color filter layer 123 and the overcoat layer 124 disposed on the rear surface of the color filter layer 123 are included. At this time, when the liquid crystal panel 110 is driven in a twisted nematic manner, in which the direction of the liquid crystal cell provided in the liquid crystal layer 130 is twisted, the CF substrate 120 includes pixels of a plurality of pixels. The semiconductor device may further include a common electrode 125 disposed on the rear surface of the overcoat layer 124 including the region P.

The black matrix layer 122 is made of a material of a color that absorbs or blocks light, thereby preventing light leakage around the pixel area P. In this case, when the black matrix layer 122 is formed of a conductive material, the touch voltage Vtouch stored in the first storage capacitor Cst may vary due to the AC voltage applied to the compensation electrode 300. Therefore, in order to prevent this, the black matrix layer 122 is made of an insulating acrylic or polymer-based material.

The color filter layer 123 is disposed in each pixel of the plurality of pixels and includes a dye corresponding to any one of R (Red), G (Green), and B (Blue), and includes a liquid crystal layer ( In the light transmitted through 130, only the light of the corresponding R (Red), G (Green), and B (Blue) wavelength bands is separated and emitted. In this case, the color filter layer 123 may include dyes of colors other than R (Red), G (Green), and B (Blue).

The overcoat layer 124 is formed on the entire surface of the rear surface of the color filter layer 123 so that the surface of the color filter layer 123 facing the liquid crystal layer is flattened so that the CF substrate (regardless of whether the color filter layer 123 is formed) The distance between the 120 and the TFT substrate 110 is made constant.

Next, as illustrated in FIG. 7, the spacers 140 are disposed on a portion of the rear surface of the overcoat layer 124 corresponding to the outer portion of the pixel region P. As shown in FIG. In this case, the spacers 140 are arranged in a matrix form spaced apart at predetermined intervals along the horizontal and vertical directions so that the gap between the TFT substrate 110 and the CF substrate 120 can be maintained uniformly. .

The plurality of first lead electrodes 150 may be spaced apart at predetermined intervals and disposed on portions of the rear surface of the overcoat layer 124 including at least one spacer 140 corresponding to the plurality of spacers 140. That is, one first lead electrode 150 is formed on a portion of the rear surface of the overcoat layer 124 to cover at least one spacer 140. The first lead electrode 150 is for forming a first storage capacitor Cst1 for sensing a touch. The larger the number of the first lead electrodes 150, the more accurate sensing can be performed, whereas the plurality of first lead electrodes 150 is provided. Along with the number of, the number of the second lead electrodes 160, the switch transistors Ts and the lead out lines RL is increased, thereby increasing the manufacturing cost. Accordingly, the number of spacers 140 corresponding to the plurality of first lead electrodes 150 may be determined in consideration of sensing accuracy and manufacturing cost.

In addition, since the plurality of first lead electrodes 150 are disposed outside the pixel area P, any one of conductive materials such as metal in the form of a thin film may be provided, but such as indium-tin oxide (ITO). The transparent conductive material may be formed on the rear surface of the overcoat layer 124 together with the common electrode 125. In addition, the plurality of second lead electrodes 160 may be formed on the TFT substrate 110 together with a pixel electrode (not shown) using a transparent conductive material such as indium-tin oxide (ITO).

The liquid crystal panel 100 configured as described above forms a plurality of pixels to display an image, and the plurality of first storage capacitors Cst1 generated between the compensation electrode 300 and the plurality of first lead electrodes 150. The touched position is sensed by detecting a coordinate value corresponding to the first storage capacitor Cst1 changed by the touch.

8 is a circuit diagram briefly illustrating a touch sensing principle of a liquid crystal panel according to an exemplary embodiment of the present invention, and FIG. 9 is a circuit diagram briefly showing a liquid crystal panel according to an exemplary embodiment of the present invention.

According to the exemplary embodiment of the present invention, as shown in FIG. 8, the protective substrate 400 corresponding to a portion in which a touch on the upper portion of the protective substrate 400 is generated and the compensation electrode 300 to which the AC voltage AC is applied. The first storage for storing the touch voltage (Vtouch) in the CF substrate 120 corresponding to the touch capacitor (Ctouch) is generated, and the compensation electrode 300 to which the AC voltage is applied and the first lead electrode 150 The capacitor Cst1 is generated. Here, the touch voltage Vtouch has a predetermined initial value by the AC voltage AC applied to the compensation electrode 300.

When the upper portion of the protective substrate 400 is touched while the first storage capacitor Cst1 stores the initial touch voltage Vtouch, the touch capacitor Ctouch affected by the touch is variable, and the touch capacitor ( According to the change of Ctouch, the touch voltage Vtouch also changes. Accordingly, the touched position is detected by a method of detecting the position of the first lead electrode 150 corresponding to the first storage capacitor Cst1 storing the touch voltage Vtouch having a value different from the initial value. Touch sensing can be performed.

That is, as illustrated in FIG. 9, a gate is connected to the gate line GL, a source is connected to the second lead electrode LD, and the readout of the switch transistor Ts. A drain is connected to the line RL. The switch transistor Ts is turned on-off according to a gate signal applied through the gate line GL, and when turned on, the switch transistor Ts is stored in the first storage capacitor Cst1 applied through the second lead electrode LD. The touch voltage Vtouch is output to the readout line RL.

The lead-out line RL is connected to a lead-out driver circuit (not shown), and the lead-out driver circuit (not shown) recognizes the touch voltage Vtouch applied to the lead-out line RL and changes by touch. Detect whether or not.

In the display transistor Td illustrated in FIG. 9, a gate is connected to the gate line GL, and a source is connected to the data line DL. The display transistor Td is turned on and off according to the gate signal applied through the gate line GL, and when turned on, the display transistor Td outputs the applied data signal to the pixel electrode (not shown) through the data line DL.

The liquid crystal capacitor Clc refers to a capacitor generated in the liquid crystal layer 130 between the pixel electrode (not shown) and the common electrode (not shown). The liquid crystal capacitor Clc is charged to a predetermined voltage by the pixel voltage corresponding to the data signal and the common voltage Vcom applied to the common electrode (not shown). The liquid crystal capacitor Clc is charged to the electric field of the liquid crystal layer 130 formed at this time. As a result, the direction of the liquid crystal cell included in the liquid crystal layer 130 is adjusted to adjust the light transmittance.

The second storage capacitor Cst2 is provided so that the electric field formed in the liquid crystal layer can be maintained for a predetermined period even after the display transistor Td is turned off.

As described above, the liquid crystal panel 100 according to the exemplary embodiment of the present invention includes a compensation electrode 300, a plurality of first lead electrodes 150, and a plurality of second electrodes disposed on the upper and lower portions of the CF substrate 120, respectively. The switch electrode Ts and the lead-out line RL disposed on the lead electrode 160 and the TFT substrate 110 are integrally provided with the touch panel. As described above, the liquid crystal panel 100 integrally provided with the touch panel may exclude an adhesive layer for bonding the touch panel and the liquid crystal panel while the touch panel is added, and thus may prevent a defect caused by the adhesive layer. In addition, since the liquid crystal panel and the touch panel are integrally provided, the overall thickness and weight may be minimized, and thus, the portability may be improved by a slim design. In addition, since the first lead electrode 150 may be formed at the same time as the common electrode 125 and the second lead electrode 160 may be formed at the same time as the pixel electrode (not shown), the manufacturing process may be simplified. Can improve.

The present invention described above is not limited to the above-described embodiment and the accompanying drawings, and various substitutions, modifications, and changes may be made without departing from the technical spirit of the present invention.

1 is a cross-sectional view of a touch panel attached liquid crystal display device according to the related art.

2A is a cross-sectional view illustrating an example of the touch panel illustrated in FIG. 1.

2B is a cross-sectional view illustrating another example of the touch panel illustrated in FIG. 1.

3 is a cross-sectional view illustrating a touch panel integrated liquid crystal display device according to an exemplary embodiment of the present invention.

FIG. 4 is a plan view corresponding to one pixel of the thin film transistor array substrate shown in FIG. 3.

FIG. 5 is a plan view illustrating the color filter array substrate illustrated in FIG. 3.

6 is a cross-sectional view taken along line AA ′ of FIG. 5.

FIG. 7 is a cross-sectional view taken along line BB ′ shown in FIG. 5.

8 is a circuit diagram briefly illustrating a touch sensing principle of a liquid crystal panel according to an exemplary embodiment of the present invention.

9 is a circuit diagram schematically illustrating a liquid crystal panel according to an exemplary embodiment of the present invention.

<Description of identification numbers for the main parts of the drawings>

100: liquid crystal panel 110: thin film transistor array substrate (TFT substrate)

120: color filter array substrate (CF substrate) 130: liquid crystal layer

140: spacer 150: first lead electrode

160: second lead electrode 300: compensation electrode

Claims (9)

A thin film transistor array substrate and a color filter array substrate facing each other; A plurality of spacers disposed between the thin film transistor array substrate and the color filter array substrate such that a gap between the thin film transistor array substrate and the color filter array substrate is maintained; A liquid crystal layer filled between the thin film transistor array substrate and the color filter array substrate; A plurality of first lead electrodes spaced at predetermined intervals and disposed on a portion of a rear surface of the color filter array substrate including at least one corresponding spacer among the plurality of spacers; A plurality of second lead electrodes disposed on an upper surface of the thin film transistor array substrate to be in contact with the plurality of first lead electrodes, respectively; And And a compensation electrode disposed on an upper surface of the color filter array substrate and configured to receive an alternating voltage. The method of claim 1, The thin film transistor array substrate, A plurality of gate lines and a plurality of data lines disposed to cross each other to define a pixel area; A plurality of display transistors disposed at intersections of the gate lines and the data lines; A plurality of lead-out lines crossing the gate lines and arranged in parallel to the data lines; And And a plurality of switch transistors respectively connected to the plurality of second lead electrodes and disposed at intersections of the gate line and the lead out line. The method of claim 2, Each of the plurality of switch transistors, The touch panel integrated type is turned on and off according to a gate signal through the gate line, and when turned on, the touch voltage accumulated in the capacitance between the compensation electrode and the first lead electrode is output to the lead out line. LCD display device. The method of claim 2, The color filter array substrate, A black matrix layer disposed to correspond to the outside of the pixel area; A color filter layer at least partially overlapping the black matrix layer and disposed to correspond to the pixel area; And And an overcoat layer disposed on a rear surface of the color filter layer so that the surface of the rear surface of the color filter layer is flat and having the plurality of spacers and the plurality of first lead electrodes formed on the rear surface of the color filter layer. . 5. The method of claim 4, The black matrix layer is a touch panel integrated liquid crystal display device, characterized in that made of an acrylic or polymer-based material. 5. The method of claim 4, The color filter array substrate, And a common electrode on the rear surface of the overcoat layer, the common electrode corresponding to the pixel area and insulated from the first lead electrode. The method of claim 2, And a protective substrate disposed on an upper surface of the compensation electrode. The method of claim 1, And the plurality of first lead electrodes are spaced apart at a predetermined interval along a first direction and a second direction perpendicular to the first direction. The method of claim 8, And the first lead electrode corresponds to two or more consecutive spacers.

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