KR101243157B1 - Liquid crystal display device - Google Patents

Abstract

The present invention relates to a liquid crystal display device capable of preventing static electricity, comprising: first and second substrates having an image display unit defined therein; A seal pattern formed at an outer side of the recall display unit to bond the first and second substrates together; A conductive pad formed outside the seal pattern of the first substrate; A conductive black matrix formed on the second substrate; A silver dot electrically connecting the conductive pad and the conductive black matrix; And a liquid crystal layer formed between the first and second substrates.

Static, Silver Dot, Conductive Black Matrix, Topcase

Description

Liquid crystal display device {LIQUID CRYSTAL DISPLAY DEVICE}

1A and 1B show a general horizontal field type liquid crystal display device, in which FIG. 1A is a plan view, and FIG. 1B is a sectional view taken along line II ′ of FIG. 1A.

2 is a view showing a static discharge structure using a transparent electrode pattern and a top case.

3 is a view showing an electrostatic discharge structure using a conductive polarizing plate and a top case.

4 is a plan view schematically showing a liquid crystal display panel according to the present invention;

5 is a cross-sectional view taken along the line II-II 'of FIG. 4;

*** Explanation of symbols for main parts of drawing ***

110: thin film transistor array substrate 116: seal pattern

120: color filter substrate 121: conductive black matrix

140 and 143: polarizer 150: conductive pad

153: conductive tape 160: silver dot

170: optical sheet 190: backlight

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a liquid crystal display device, and in particular, by using a conductive black matrix, electrically connecting the black matrix with a pad formed on the lower substrate, and electrically connecting the pad to an external device, thereby preventing static electricity. The present invention relates to a liquid crystal display device.

Liquid crystal display devices are mainly used as flat panel display devices having high quality and low power. The liquid crystal display device is bonded so that the thin film transistor array substrate and the color filter substrate face each other at uniform intervals, and a liquid crystal layer is formed between the thin film transistor array substrate and the color filter substrate.

In the thin film transistor array substrate, pixels are arranged in a matrix form, and a thin film transistor, a pixel electrode, and a capacitor are formed in a unit pixel, and the color filter substrate is a common electrode and an actual color for applying an electric field to the liquid crystal layer together with the pixel electrode. An RGB color filter and a black matrix are implemented to implement the.

On the other hand, an alignment layer is formed on the opposite surface of the thin film transistor array substrate and the color filter substrate, and rubbing is performed so that the liquid crystal layer is arranged in a constant direction. In this case, the liquid crystal is rotated by dielectric anisotropy when an electric field is applied between the pixel electrode formed for each unit pixel of the thin film transistor array substrate and the common electrode formed on the front surface of the color filter substrate, thereby passing or blocking light per unit pixel. Characters or images are displayed. However, the above-described twisted nematic mode liquid crystal display device has a disadvantage in that the viewing angle is narrow.

Therefore, a horizontal field type liquid crystal display (In Plane Switching mode LCD) that solves the viewing angle problem by aligning the liquid crystal molecules almost in the direction of the substrate has been actively studied in recent years.

FIG. 1 schematically illustrates a unit pixel of a general horizontal field type liquid crystal display device. FIG. 1A is a plan view, and FIG. 1B is a cross-sectional view taken along line II ′ of FIG. 1A.

As shown in the figure, the gate line 1 and the data line 3 are vertically and horizontally arranged on the transparent first substrate 10 to define a pixel area. In an actual liquid crystal display device, n gate lines 1 and m data lines 3 intersect with n x m pixels, but only one pixel is shown in the figure for simplicity.

A thin film transistor 9 composed of a gate electrode 1a, a semiconductor layer 5, and source / drain electrodes 2a and 2b is disposed at an intersection point of the gate line 1 and the data line 3. The gate electrode 1a and the source / drain electrodes 2a and 2b are connected to the gate line 1 and the data line 3, respectively. In addition, the gate insulating film 8 is laminated over the entire substrate.

The common line 4 is arranged in parallel with the gate line 1 in the pixel area, and at least one pair of electrodes for switching the liquid crystal molecules, that is, the common electrode 6 and the pixel electrode 7 are parallel with the data line. Are arranged. The common electrode 6 is formed at the same time as the gate line 1 and connected to the common line 4, and the pixel electrode 7 is formed at the same time as the source / drain electrodes 2a and 2b to form the thin film transistor 9. It is connected to the drain electrode 2b. A protective film 11 is formed over the entire substrate including the source / drain electrodes 2a and 2b. In addition, the pixel electrode line 14 formed to overlap the common line 4 and connected to the pixel electrode 7 forms the storage capacitor Cst with an insulating film 8 interposed therebetween. do.

In addition, the second substrate 20 includes a black matrix 21 for preventing light leakage into the thin film transistor 9, the gate line 1, and the data line 3, and a color filter 23 for realizing color. The overcoat film for planarizing the color filter 23 may be applied thereon. On the opposing surfaces of the first substrate 10 and the second substrate 20, alignment films 12a and 12b for determining the initial alignment direction of the liquid crystal are coated.

In addition, a liquid crystal layer 13 is formed between the first substrate 10 and the second substrate 20 to control light transmittance by a voltage applied to the common electrode 6 and the pixel electrode 7. have.

The conventional liquid crystal display device having the structure as described above has the advantage of improving the viewing angle because the common electrodes 6a and 6b and the pixel electrode 7 are arranged on the same plane to generate a transverse electric field.

On the other hand, by driving the liquid crystal by a horizontal electric field, the first and second substrates 10 and 20 are electrically isolated, respectively, so that the amount of static electricity generated is relatively high and the discharge is not easy.

In order to solve the problem of static electricity generation, as shown in FIG. 2, the transparent electrode pattern 27 is formed on the rear surface of the second substrate 20 (color filter substrate) and the top is formed using the conductive material 51. A structure for electrically connecting with the case 54 has been proposed. However, the light transmittance is lowered by the transparent electrode pattern 27 shown in FIG. 2 and the transparent electrode pattern 27 is formed, thereby causing a problem in that the process and the cost are increased.

Accordingly, as shown in FIG. 3, a structure for discharging static electricity to the outside through the top case 54 using the conductive polarizing plate 53 has been proposed. However, the structure shown in FIG. 3 also has a problem in that the cost increases in order to fabricate the polarizing plate 53 having conductivity.

Accordingly, the present invention has been made to solve the above problems, an object of the present invention is to form a conductive black matrix on the color filter substrate, and to form a conductive pad on one side of the thin film transistor array substrate, The present invention provides a liquid crystal display device capable of preventing static electricity by electrically connecting the conductive pads with silver dots and electrically connecting the conductive pads with the top case.

Other objects and features of the present invention will be described in detail in the configuration and claims of the following invention.

The present invention for achieving the above object is a first and second substrate with an image display portion defined; A seal pattern formed at an outer side of the recall display unit to bond the first and second substrates together; A conductive pad formed outside the seal pattern of the first substrate; A conductive black matrix formed on the second substrate; A silver dot electrically connecting the conductive pad and the conductive black matrix; And a liquid crystal layer formed between the first and second substrates.

The conductive pad is electrically connected to an external device by a conductive tape, and the external device may be a top case.

The first substrate may include a plurality of gate lines and data lines that vertically intersect to define a plurality of pixels; A switching element formed at an intersection of the gate line and the data line to switch each pixel; And a common electrode and a pixel electrode for generating a horizontal electric field in the pixel.

The second substrate further includes a color filter formed on the conductive black matrix.

In addition, the present invention provides a liquid crystal panel including a color filter substrate including a conductive black matrix, a thin film transistor array substrate including a conductive pad, and a silver dot electrically connecting the conductive black matrix and the conductive pad; A liquid crystal panel; A backlight for supplying light to the liquid crystal panel; A main support for mounting the liquid crystal panel and the optical sheet; And a top case which presses an edge of the liquid crystal panel to support the liquid crystal panel and is in electrical contact with the conductive pad.

In this case, the conductive black matrix and the top case may be electrically connected by a conductive tape.

As described above, the present invention uses a conductive black matrix on the upper substrate (color filter substrate), and forms a conductive pad on the lower substrate (thin film transistor array substrate) to silver dot (Ag dot) the conductive black matrix and the conductive pad. By electrically connecting through and connecting the conductive pad to an external device (top case) through a conductive material such as a conductive tape, it is possible to effectively prevent static electricity of the liquid crystal display device.

That is, in the related art, since the static electricity is prevented through the conductive polarizing plate or the transparent electrode pattern on the rear surface of the upper substrate, there is a problem in that the cost increases and the process becomes complicated. It is electrically connected, and by connecting it with external equipment, it effectively prevents static electricity.

Hereinafter, the liquid crystal display device according to the present invention will be described in more detail with reference to the accompanying drawings.

4 is a plan view schematically showing a liquid crystal display panel according to the present invention.

As shown in the figure, the liquid crystal display panel 100 according to the present invention includes a thin film transistor array substrate 110 and a color filter substrate 120 and a liquid crystal layer (not shown) interposed therebetween.

The thin film transistor array substrate 110 includes a plurality of gate lines 101 arranged in a first direction and a plurality of liquid crystal cells defined by a plurality of data lines 103 vertically intersecting the gate lines 101. An image display unit 113 arranged to be connected to the image display unit 113, a gate pad 114 connected to the gate line 101 of the image display unit 113 to transmit an external signal, and a data pad connected to the data lines 103. 115).

In this case, the gate pad 114 and the data pad 115 are cut into unit panels, and are formed in the edge region of the thin film transistor array substrate 110 that does not overlap the color filter substrate 120. 114 supplies a gate signal supplied from a gate driver circuit (not shown) to the gate lines 101 of the image display unit 113, and the data pad unit 115 is supplied from a data driver circuit (not shown). The data signal to be supplied is supplied to the data lines 103 of the image display unit 113. In this case, the gate driving circuit may be formed separately on the outside or on the substrate.

Although not shown in the drawings, a thin film transistor is formed as a switching element for switching respective liquid crystal cells in a region where the gate line 101 and the data line 103 cross each other. The thin film transistor includes a gate electrode, a semiconductor layer, and a source / drain electrode, and the gate electrode and the semiconductor layer are insulated by a gate insulating film (not shown) interposed therebetween. In this case, the gate insulating film (not shown) is formed over the entire surface of the thin film transistor array substrate 110, and a protective film (not shown) for protecting the thin film transistor is formed over the entire surface of the substrate. Therefore, a gate insulating film and a protective film are stacked on the thin film transistor array substrate 110 on the outside of the image display unit 113.

In addition, the color filter substrate 120 includes a color filter coated separately for each cell region, a switching element of the thin film transistor array substrate 110, a gate line 101, a data line 103, and an image display unit 113. A black matrix (not shown) is formed between the pad parts 114 and 115 to prevent light leakage, and the black matrix is formed of a conductive material such as chromium (Cr).

On the other hand, a seal pattern 116 is formed on the upper substrate (color filter substrate; 120) corresponding to the image display unit 113 to bond with the thin film transistor array substrate 110, and the image display unit 113 The outer side of the conductive pad 150 is formed.

The conductive pad 150 may be formed of a transparent electrode such as indium tin oxide (ITO). In particular, when the transparent pattern is formed on the gate pad 114 or the data pad 115 to be connected to the driving unit, Can be formed together. Therefore, a separate process for forming the conductive pad 150 is not added.

In addition, although not shown in detail in the drawing, the conductive black matrix formed on the color filter substrate 120 and the conductive pad 150 are electrically connected through a silver dot, and the conductive pad 150 is an external device ( Electrically connected).

That is, the liquid crystal display panel configured as described above is supported and assembled by a mechanism such as a main support, a top case, etc. The conductive pad 150 may be connected to the top case.

FIG. 5 is a cross-sectional view of the II-II 'of FIG. 4. In particular, FIG. 5 is a cross-sectional view of a liquid crystal display including both a liquid crystal panel and a backlight mounted on an instrument. The electrical contact of the battery will be described in detail.

As shown in the figure, the liquid crystal display device 100 ′ according to the present invention is disposed under the liquid crystal panel 100 and the liquid crystal panel 100, and provides a backlight unit for supplying light to the liquid crystal panel 100 ( 190).

In the liquid crystal panel 100, the color filter substrate 110 and the thin film transistor substrate 120 are bonded by the seal pattern 116 at regular intervals, and the liquid crystal layer is formed in the bonded space. In addition, polarizing plates 141 and 143 are attached to both surfaces of the liquid crystal panel 100, and the polarizing plates 141 and 143 may use a general polarizing plate having no conductivity.

In addition, the conductive black matrix 121 formed on the color filter substrate 120 is electrically connected to the conductive pad 150 formed on the thin film transistor array substrate 110 through the silver dot 160.

In addition, an optical sheet 170 is provided between the liquid crystal panel 100 and the backlight 190 to improve light efficiency of the light generated by the backlight 190 toward the liquid crystal panel 100.

The liquid crystal panel 100, the optical sheet 170, and the backlight 190 are seated on a main support 195, and the upper edge of the liquid crystal panel 100 is compressed to compress the upper edge of the main support 195. The liquid crystal panel 100 and the backlight 190 are fixed to the main support 195 by a top case 153 coupled to the side surface. In addition, a lower cover 181 for supporting and protecting the mold frame 195 is configured under the main support 195.

The conductive pad 150 formed on the thin film transistor array substrate 110 and contacting the conductive black matrix 121 through the silver dot 160 is also electrically connected to the top case 183. In this case, the conductive pad 150 and the top case 183 may be electrically connected through a conductive tape 153 such as aluminum tape. In addition, the conductive pad 150 and the top case 183 may be connected through another conductive material.

As such, in the present invention, the conductive black matrix 121 formed on the color filter substrate 120 and the conductive pad 150 formed on the thin film transistor array substrate 110 are electrically connected to each other through the silver dot 160. The pad 150 is electrically grounded to the top case 183 through the conductive tape 153 to prevent static electricity from occurring in the liquid crystal panel 100.

As described above, since the present invention does not use the transparent electrode pattern on the back of the color filter substrate, the transmittance can be improved compared to the conventional art. Furthermore, since the conductive polarizer is not used, the cost can be reduced.

In addition, the present invention uses a conductive black matrix on the color filter substrate, a conductive pad is formed on the thin film transistor array substrate to form a transparent pad for connection with a driving circuit on the gate pad or the data pad, and the conductive black matrix By electrically connecting the conductive pads with silver dots, an additional process for forming the conductive pads can be omitted.

Furthermore, the present invention can effectively prevent static electricity generated in the liquid crystal panel by grounding the conductive pads on the top case to discharge static electricity, and as a means for electrically connecting the conductive pads and the top case, as described in the detailed description. In addition to the conductive tape, any means may be used as long as the material has conductivity.

As described above, the basic concept of the present invention is to electrically connect the conductive black matrix to the conductive pad of the lower substrate and to electrically ground the conductive pad to an external device. The present invention provides a liquid crystal display panel of the IPS mode described in the detailed description. In addition, the present invention can be easily applied to liquid crystal display panels of TN mode (twisted nematic mode), electric controlled birefringence (ECB), and liquid crystal display panels of VA (Vertical Alignment) mode.

As described above, according to the present invention, a black matrix of a conductive material is used to form a lower substrate conductive pad, electrically connect them through silver dots, and ground the conductive pad to an external device, thereby preventing static electricity. It can prevent.

As described above, the present invention eliminates the need for a conventional transparent electrode pattern or a conductive polarizing plate, thereby improving light transmittance, reducing costs, and improving productivity.

Claims (8)

First and second substrates on which an image display unit is defined; A seal pattern formed at an outer side of the recall display unit to bond the first and second substrates together; A conductive pad formed outside the seal pattern of the first substrate; A conductive black matrix formed on the second substrate; A silver dot electrically connecting the conductive pad and the conductive black matrix; A conductive tape electrically connecting the conductive pad and an external appliance to discharge static electricity through the external appliance; And And a liquid crystal layer formed between the first and second substrates. delete delete The method of claim 1, The external device is a liquid crystal display device, characterized in that the top case. The method of claim 1, Wherein the first substrate comprises: A plurality of gate lines and data lines that vertically intersect to define a plurality of pixels; A switching element formed at an intersection of the gate line and the data line to switch each pixel; And And a common electrode and a pixel electrode for generating a horizontal electric field in the pixel. The method of claim 1, The second substrate, And a color filter formed on the conductive black matrix. A color filter substrate comprising a conductive black matrix, Thin film transistor array substrate comprising a conductive pad, A liquid crystal panel including a silver dot electrically connecting the conductive black matrix and the conductive pad; A backlight for supplying light to the liquid crystal panel; A main support for mounting the liquid crystal panel and the backlight; A top case pressing an edge of the liquid crystal panel to support the liquid crystal panel and to be in electrical contact with the conductive pad; And And a conductive tape electrically connecting the conductive pad and the top case to discharge static electricity through the top case. delete

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