KR20080012594A - Liquid crystal display panel with a built-in touch screen - Google Patents

Abstract

An LCD panel with a built-in touch screen is provided to form a first sensing electrode in the rear of a black matrix and use a second sensing electrode as a data line, thereby making the LCD panel have the same weight and thickness as an LCD without having a digitizer and simplifying a manufacturing process. An LCD(Liquid Crystal Display) panel with a built-in touch screen comprises a color filter substrate(100), a TFT(Thin Film Transistor) substrate(200), a liquid crystal layer, a first sensing electrode(115) and a second sensing electrode(240). The color filter substrate has a black matrix(110) formed to prevent light leakage. The TFT substrate has a gate line(220) and a data line(240) formed to transfer signals. The liquid crystal layer is injected between the color filter substrate and the TFT substrate. The first sensing electrode is formed on the black matrix to identify a position where touch is generated. The second sensing electrode is formed oppositely to the first sensing electrode on the TFT substrate.

Description

Liquid crystal display panel with a built-in touch screen}

1 is a schematic plan view showing a color filter substrate of a touch screen embedded liquid crystal display panel according to a first embodiment of the present invention.

2 is a cross-sectional view of a liquid crystal display panel with a touch screen according to a first embodiment of the present invention taken on line A-A of FIG.

3 is a cross-sectional view for describing an operation of a touch screen built-in liquid crystal display panel according to a first exemplary embodiment of the present invention.

4 to 8 are cross-sectional views for explaining the manufacturing process of the color filter substrate according to the first embodiment of the present invention.

9 is a schematic plan view showing a color filter substrate of a liquid crystal display panel with a touch screen according to a second embodiment of the present invention.

10 is a cross-sectional view of a liquid crystal display panel with a touch screen according to a second embodiment of the present invention taken on line B-B of FIG.

11 is a schematic cross-sectional view of a liquid crystal display panel with a touch screen according to a third embodiment of the present invention.

<Explanation of symbols for the main parts of the drawings>

100, 200: substrate 110: black matrix

115: sensing film 120: color filter

130: overcoat film 140: common electrode

220: gate line 240: data line

250: protective film 260: pixel electrode

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a touch screen embedded liquid crystal display panel, and more particularly, to a touch screen embedded liquid crystal display panel having a sensor formed on a rear surface of a black matrix to identify a position where a touch occurs on the liquid crystal display panel.

Touch screen is a new input method that can replace an input method such as a mouse or a keyboard, and a new input method that can directly input information on the screen using a hand or a pen. In particular, the touch screen is evaluated as the most ideal input method under the GUI (Graphical User Interface) environment because the user can directly perform a desired task while viewing the screen, and anyone can easily operate it. It is widely used in various fields such as terminals of government offices, various medical equipment, tourism and information display devices of major organizations.

As mentioned above, the portable PC adopts a method that can be used only by attaching a digitizer to the back of the liquid crystal display panel and using a specific pen. This method is disadvantageous in terms of weight and thickness because a separate digitizer must be attached to the liquid crystal display panel. This is because a portable PC is important for mobility, the increase in weight and thickness as described above may act as a fatal disadvantage in mobility.

In addition, a touch sensor is formed on a liquid crystal display panel without using a digitizer on the touch screen. A hybrid touch screen method such as a resistive method or a capacitive method may be used depending on a sensor element that detects a touch input. However, this has a problem that is difficult to implement in the process.

SUMMARY OF THE INVENTION An object of the present invention is to provide a touch screen embedded liquid crystal display panel having the same weight and thickness as a liquid crystal display panel without a digitizer.

Another object of the present invention is to provide a touch screen embedded liquid crystal display panel with a simple manufacturing process.

In order to achieve the above object, the present invention provides a color filter substrate having a black matrix for preventing light leakage, a thin film transistor substrate having a gate line and a data line for transmitting a signal, and the color filter substrate and the thin film transistor substrate. And a first sensing electrode formed on the black matrix to identify a position at which a touch occurs, and a second sensing electrode formed on the thin film transistor substrate to face the first sensing electrode. A touch screen embedded liquid crystal display panel is provided.

In this case, the second sensing electrode may be a data line. However, the present invention is not limited thereto, and a pixel electrode may be formed on the thin film transistor substrate, and the second sensing electrode may be formed on the same plane between the pixel electrodes. In addition, the first sensing electrode may be a transparent electrode.

In addition, the black matrix may be a metal material. In this case, the black matrix has a lattice structure and may be electrically connected only in the gate line direction.

However, the present invention is not limited thereto, and further includes an insulating layer formed between the black matrix and the first sensing electrode, and is formed between the insulating layer and the first sensing electrode and changes in the amount of charge caused by the first sensing electrode and the data line. It may further include a sensing line for transmitting.

Hereinafter, exemplary embodiments of the present invention will be described in detail with reference to the accompanying drawings.

However, the present invention is not limited to the embodiments disclosed below, but will be implemented in various forms, and only the embodiments are intended to complete the disclosure of the present invention, and to those skilled in the art to fully understand the scope of the invention. It is provided to inform you. Like reference numerals in the drawings refer to like elements. On the other hand, when a part such as a layer, a film, an area, or a plate is expressed as being on or above another part, not only when each part is directly above or directly above the other part but also another part between each part and another part This includes cases.

1 is a schematic plan view showing a color filter substrate of a touch screen embedded liquid crystal display panel according to a first embodiment of the present invention, and FIG. 2 is a touch screen according to the first embodiment of the present invention taken at line AA of FIG. It is sectional drawing of a built-in liquid crystal display panel.

As illustrated in FIGS. 1 and 2, a touch screen embedded liquid crystal display panel includes a thin film transistor substrate 2000, a color filter substrate 1000 bonded to the thin film transistor substrate 2000, and the thin film. And a touch sensor formed on the transistor substrate 2000 and the color filter substrate 1000. In addition, a liquid crystal (not shown) is injected between the thin film transistor substrate 2000 and the color filter substrate 1000.

The thin film transistor substrate 2000 is for controlling the direction of the liquid crystal, and transmits a gate signal on a transparent insulating substrate, and includes a plurality of gate lines 220 formed in a horizontal direction on the substrate, and the plurality of gate lines. A plurality of data lines 240 formed to be insulated from and intersect with the 220, a pixel electrode 260 and a thin film transistor formed in an intersection area of the plurality of gate lines 220 and the plurality of data lines 240, respectively. City).

The thin film transistor is configured to charge a pixel signal supplied to the data line 240 to the pixel electrode 260 in response to a signal supplied to the gate line 220, and includes a gate electrode, a drain electrode, a channel layer, and a source. An electrode. One thin film transistor is connected to each pixel electrode 260. A gate line 220 is commonly connected to the gate electrodes of the thin film transistors belonging to one row of the thin film transistors arranged in a matrix form, and a data line is provided to the source electrode of the thin film transistors belonging to one column of the thin film transistors arranged in a matrix form. 240 is connected. The drain electrode is connected to the pixel electrode 260.

The pixel electrode 260 is formed on the passivation layer 250 and disposed in a matrix form on the thin film transistor substrate 2000. The pixel electrode 260 is connected to the drain electrode of the thin film transistor through a contact hole. In addition, the pixel electrode 260 may generally use indium tin oxide (ITO) or indium zinc oxide (IZO) made of a transparent conductive material.

The color filter substrate 1000 is used to adjust the color of the white light whose luminance is adjusted by the thin film transistor substrate 2000. The color filter substrate 1000 is adjacent to the light leakage on the insulating substrate 100 made of a transparent insulating material such as glass. The black matrix 110 and the color filters 120 of red (R), green (G), and blue (B) and the overcoat layer formed on the color filter 120 to prevent optical interference between them. 130 and a common electrode 140 formed of a transparent conductive material such as ITO or IZO on the overcoat layer 130.

The color filter 120 is formed to be divided into red (R), green (G), and blue (B), and the black matrix 110 to transmit the red (R), green (G), and blue (B) light, respectively. It is formed to cover the opening of). The color filter 120 is a color filter of the red (R), green (G), blue (B) is arranged in a matrix form to allow color display by transmitting light of a specific wavelength band. The color filter 120 is disposed at a position corresponding to each pixel electrode 260 of the thin film transistor substrate 2000, and the common electrode 140 covers the entire surface of the color filter substrate 1000 such that the color filter 120 is covered. Formed over. In this case, the area of the color filter substrate 1000 is slightly smaller than the thin film transistor substrate 2000 in order to expose the signal line of the thin film transistor substrate 2000. In addition, an overcoat layer 130 formed of an organic material is formed on the rear surface of the color filter 120.

The black matrix 110 is formed in the thin film transistor region to prevent light leakage from an area other than the pixel region and optical interference between adjacent pixel regions. That is, the black matrix 110 has an opening that opens an area of the pixel electrode 260 of the thin film transistor substrate 2000. In this case, the sensing film 115 is formed on the rear surface of the black matrix 110 of the color filter substrate 1000 according to the present embodiment.

In the liquid crystal display panel according to the present exemplary embodiment, the sensing film 115 formed on the rear surface of the black matrix 110 is used as the first sensing electrode, and the data line 240 formed on the thin film transistor substrate 2000 is used as the second sensing electrode. The touch sensor may identify a position where a touch occurs on the liquid crystal display panel. In this case, the liquid crystal injected between the color filter substrate 1000 and the thin film transistor substrate 2000 serves as a dielectric, and the black matrix 110 functions as a wiring of the first sensing electrode, that is, a first sensing wiring. Done. That is, the touch sensor according to the present embodiment is a capacitive sensor using a liquid crystal injected between the first and second sensing electrodes and the first and second sensing electrodes, and the charge amount of the first and second sensing electrodes changes. Check to identify the location where the touch occurs on the liquid crystal display panel. To this end, the black matrix 110 may be electrically shorted in the direction of the data line 240 in the region where the first sensing electrode is formed so that the black matrix 110 may be a wiring formed in the same direction as the gate line 220. have.

The first sensing electrode includes one selected from a group of transparent conductive metals including indium tin oxide (ITO), tin oxide (TO), or indium zinc oxide (IZO). can do. In addition, the data line 240 including the second sensing electrode extends in a direction crossing the black matrix 110 extending in the gate line direction to function as the second sensing wiring. That is, an area of the data line 240 in an area crossing the first sensing wire functions as a second sensing electrode, and an area of the data line 240 other than the second sensing electrode functions as a second sensing wire.

As shown in FIG. 3, the liquid crystal display panel according to the present exemplary embodiment having the above structure has the first sensing electrode and the thin film transistor substrate 2000 in a region where the user's finger is touched when the user touches on the liquid crystal display panel. The amount of charges between the data line 240, that is, the second sensing electrode, is changed. That is, when a reference voltage is applied to the first sensing electrode, charge is charged between the first sensing electrode and the second sensing electrode, and the charge charged by the user's finger is discharged while the charge is charged as described above. . In this case, a controller (not shown) connected to the second sensing wire including the first sensing wire and the second sensing electrode connected to the first sensing electrode senses a change in the charge amount of the first and second sensing electrodes. That is, the analog signal according to the change in the amount of charge sensed by the first and second sensing electrodes is converted into a digital signal by the A / D converter in the controller, and the converted signal is transmitted to the microcontroller in the controller. . The microcontroller generates coordinates according to the signal converted into a digital signal and transfers these coordinates to the driver. The driver operates an image displayed in an area of the liquid crystal display panel corresponding to the input coordinates in the same manner as a manipulation using an input tool such as a mouse.

As described above, the touch screen embedded liquid crystal display panel according to the present invention forms a first sensing electrode on the back of the black matrix of the color filter substrate, and uses the data line of the thin film transistor substrate as the second sensing electrode, without the digitizer attached thereto. It may have the same weight and thickness as the panel, and the manufacturing process is simpler than the conventional method using the first sensing electrode formed on the rear surface of the black matrix and the data line serving as the second sensing electrode.

Next, a manufacturing process of the color filter substrate according to the first embodiment of the present invention will be described with reference to the drawings.

4 to 8 are cross-sectional views illustrating a manufacturing process of a color filter substrate according to a first embodiment of the present invention.

Referring to FIG. 4, first, a black matrix 110 is formed on the substrate 100. In this case, as the material of the black matrix 110, a carbon-based organic material or a metal thin film such as chromium (Cr) is mainly used. In this embodiment, a metal thin film will be used.

In this case, when a carbon-based organic material is used, the black matrix 110 is formed by using a negative photoresist, and when chromium (Cr) is used, a positive type that can be developed with a developer for a negative photoresist. The resist is used to form the black matrix 110.

Next, as illustrated in FIG. 5, the sensing layer 115, that is, the first sensing electrode is formed on the black matrix 110. The first sensing electrode may deposit one selected from a group of transparent conductive metals including indium tin oxide (ITO), tin oxide (TO), or indium zinc oxide (IZO). have.

Next, as shown in FIG. 6, the color filter 120 is formed. Although not shown, the color filter 120 has a shape in which color filters representing red (R), green (G), and blue (B) are arranged in a predetermined order in a plurality of pixel areas.

The red color pattern of the color filter 120 is applied by applying a negative color photoresist (not shown) in which the pigment of the red component is dispersed on the black matrix pattern 110, and exposed using a mask (not shown), The photopolymerization initiator in the exposed area reacts to form a polymer that is not removed during development and remains in a pattern. The color filter pattern formed after development is fixed by applying heat.

Since the color filter 120 does not require the precision of the pattern formation level of the thin film transistor substrate 2000, a negative photoresist in which an unexposed portion is removed with a developer may be generally used. Here, the developer for negative photoresist can use the potassium hydroxide developer containing surfactant and aqueous potassium hydroxide solution.

Subsequently, a negative color photoresist in which green pigment is dispersed is applied to a substrate on which a red color filter is formed, and the mask of the same design is exposed and developed by moving a unit pixel separation distance, and the green color filter is developed. Is formed. Then, when the above process is repeated using a negative color photoresist in which a pigment of blue component is dispersed, the color filter 120 is formed.

However, the present invention is not limited thereto, and after laminating any one of red (R), green (G), and blue (B) color resins on the substrate 100 on which the black matrix 110 is formed, pattern the color resins. The color filter 120 may be formed.

Subsequently, when the color filter 120 is formed as shown in FIG. 7, an overcoat layer 130 is formed on the color filter 120. The overcoat layer 130 is formed on the surface of the color filter 120 in order to prevent elution of organic substances from the color filter 120 toward the liquid crystal cell and to provide good step coverage when forming the common electrode. At this time, an acrylic resin or the like may be used as the material of the overcoat film 130.

Next, as shown in FIG. 8, indium tin oxide (ITO), tin oxide (TO), or indium zinc oxide (Indium Zinc oxide) on the entire surface of the substrate 100 on which the overcoat layer 130 is formed. A common electrode 140 is formed by depositing one selected from the group of transparent conductive metals including IZO. In this case, the common electrode 140 may be deposited through a sputtering method. In addition, a cutting pattern (not shown) for cutting a portion of the common electrode 140 may be formed, and a protrusion pattern (not shown) formed of an organic insulating material for protruding the same may be formed under the common electrode 140. It may be. In this case, the protruding pattern may be formed between the pixel electrode cutouts to divide the pixel area into a plurality of domains.

After forming the common electrode 140 as described above, a culture film (not shown) is formed to complete the color filter substrate 1000 according to the present embodiment.

Next, a touch screen embedded liquid crystal display panel according to a second exemplary embodiment of the present invention will be described with reference to the accompanying drawings. Duplicate contents will be omitted or briefly described below with respect to the above-described embodiment.

FIG. 9 is a schematic plan view illustrating a color filter substrate of a touch screen embedded liquid crystal display panel according to a second embodiment of the present invention, and FIG. 10 is a touch screen according to the second embodiment of the present invention taken from the line BB of FIG. It is sectional drawing of a built-in liquid crystal display panel.

According to the second exemplary embodiment of the present invention, the liquid crystal display panel having a touch screen includes a thin film transistor substrate 2000 and a color filter substrate 1000 bonded to the thin film transistor substrate 2000 as shown in FIGS. 9 and 10. ). In this case, a black matrix 110 is formed on the color filter substrate 1000, and an insulating layer 112 is formed on a rear surface of the black matrix 110, and a sensing line 114 is formed on a rear surface of the insulating layer 112. Is formed. In addition, a sensing layer 115, that is, a first sensing electrode is formed on the rear surface of the sensing line 114. In addition, a liquid crystal (not shown) is injected between the thin film transistor substrate 2000 and the color filter substrate 1000.

The first sensing electrode is used to identify a location where a touch occurs on the liquid crystal display panel. The first sensing electrode is formed of the same material as the first embodiment described above.

In the present exemplary embodiment, a separate first sensing line 114 is formed without using the black matrix 110 as a wiring for sensing a change in the amount of charge in the first sensing electrode.

In this case, an insulating layer 112 for insulation is formed between the first sensing line 114 and the black matrix 110, and the first sensing line 114 is formed on the insulating layer 112. However, the present invention is not limited thereto, and when the carbon-based organic material is used as the black matrix 110, the insulating layer may be omitted.

Next, a liquid crystal display panel according to a third exemplary embodiment of the present invention will be described with reference to the drawings. Duplicate contents will be omitted or briefly described below with respect to the above-described embodiment.

11 is a cross-sectional view of a liquid crystal display panel according to a third exemplary embodiment of the present invention.

The liquid crystal display panel according to the third exemplary embodiment of the present invention includes a thin film transistor substrate 2000 and a color filter substrate 1000 bonded to the thin film transistor substrate 2000 as shown in FIG. 11. In this case, a black matrix 110 is formed on the color filter substrate 1000, and a sensing layer 115, that is, a first sensing electrode, is formed on the rear surface of the black matrix 110. In addition, a liquid crystal (not shown) is injected between the thin film transistor substrate 2000 and the color filter substrate 1000.

The first sensing electrode is used to identify a location where a touch occurs on the liquid crystal display panel. The first sensing electrode is formed of the same material as the first embodiment described above.

In this embodiment, the pixel electrode is used as the second sensing electrode and the second sensing wiring. That is, when the pixel electrode is formed, the pixel electrode is formed on the entire surface of the passivation layer 250 and patterned to form the pixel electrode 260, the second sensing electrode, and the second sensing wiring. In this case, the second sensing electrode and the second sensing wiring are formed between the pixel electrode 260 on the passivation layer 250.

When the data line 240 is formed on the passivation layer 250 as described above, more accurate sensing is possible.

Meanwhile, a separate sensing line may be formed on the rear surface of the black matrix 110 as in the above-described second embodiment. In this case, an insulation layer for insulation is formed between the sensing line and the black matrix 110, and the sensing line is formed on the insulation layer. However, the present invention is not limited thereto, and when the carbon-based organic material is used as the black matrix 110, the insulating layer may be omitted. In addition, the black matrix 110 may be used as the sensing line in the same manner as in the above-described first embodiment without separately forming the sensing line.

Although described above with reference to the drawings and embodiments, those skilled in the art can be variously modified and changed within the scope of the invention without departing from the spirit of the invention described in the claims below. I can understand.

As described above, the present invention forms the first sensing electrode on the back of the black matrix of the color filter substrate, and has the same weight and thickness as the liquid crystal display panel without the digitizer, with the data line as the second sensing electrode, and the manufacturing process is simple. A touch screen embedded liquid crystal display panel may be provided.

Claims (8)

A color filter substrate on which a black matrix is formed to prevent light leakage; A thin film transistor substrate having a gate line and a data line formed thereon for transmitting a signal; A liquid crystal injected between the color filter substrate and the thin film transistor substrate; A first sensing electrode formed on the black matrix to identify a location where a touch occurs; And a second sensing electrode formed on the thin film transistor substrate to face the first sensing electrode. The method according to claim 1, And the second sensing electrode is a data line. The method according to claim 1, The pixel electrode is formed on the thin film transistor substrate, The second sensing electrode is formed on the same plane between the pixel electrode, the touch screen embedded liquid crystal display panel. The method according to claim 1, And the first sensing electrode comprises a transparent electrode. The method according to claim 1, The black matrix is a touch screen embedded liquid crystal display panel, characterized in that the metal material. The method according to claim 1, And the black matrix has a lattice structure and is electrically connected only in a gate line direction. The method according to claim 1, And an insulating layer formed between the black matrix and the first sensing electrode. The method according to claim 7, And a sensing line formed between the insulating layer and the first sensing electrode and transferring a change amount of charge by the first sensing electrode and the data line.

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