KR20010060825A - Liquid crystal display - Google Patents

Abstract

PURPOSE: A liquid crystal display device is to prevent an occurrence of an electromagnetic interference(EMI) at the front face of the liquid crystal panel effectively, thereby improving a picture quality. CONSTITUTION: A thin film transistor array substrate(10) is prepared. A color filter substrate(20) having a black matrix(12) with a conductive metal material is formed on one side of a liquid crystal layer. The first conductive layer(5) of a pattern type is formed on one edge of the thin film transistor array substrate. The second conductive layer(15) of a dot type, which is in contact with the black matrix, is formed on the color filter substrate. The substrates are charged with electricity. A conductive frame chassis encloses a liquid crystal panel. The conductive frame chassis is electrically contacted with the black matrix.

Description

Liquid Crystal Display {LIQUID CRYSTAL DISPLAY}

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a liquid crystal display, and more particularly, to a liquid crystal display for reducing electromagnetic interference emitted or introduced into the front surface of a liquid crystal panel.

Liquid crystal displays (LCDs) have been developed in place of the CRT (Cathod-ray Tube), and have recently been in the spotlight in the notebook PC and monitor market. The LCD is a display device that displays a predetermined image by changing an arrangement direction of liquid crystal molecules. The LCD includes a liquid crystal panel in which a thin film transistor array substrate and a color filter substrate are bonded to each other under a liquid crystal, and electrically connected to the liquid crystal panel. And a back-light unit including a printed circuit board (PCB) for applying a predetermined electrical signal to the liquid crystal panel and a back-light functioning as a light source. In addition, the back-light unit is fixed and arranged on a plastic mold frame, and the liquid crystal panel including the printed circuit board is fixed and arranged on the back-light by a metallic frame chassis surrounding the liquid crystal panel. do.

On the other hand, in all display devices, electromagnetic interference (EMI), which acts as a factor of lowering the screen quality of the display device due to the use of electrical and electronic components, occurs. In particular, since LCD screen quality is sharply degraded by the above-mentioned EMI, various studies have recently been developed to minimize the influence of the EMI.

Here, the EMI generated in the LCD is mainly generated at the connection portion between the source PCB and the gate PCB, and plays a noise role on the image signal applied to the liquid crystal panel, and consequently, reduces the screen quality of the LCD. Accordingly, in order to block the EMI, conventionally, the metallic frame chassis and the PCB are connected to each other by a conductive coupling member such as a screw, thereby reinforcing the ground by the metallic frame chassis and simultaneously reducing EMI. have.

However, the use of the above-described metallic frame chassis does not directly block the effects of EMI radiation and EMI of peripheral devices. Therefore, in a typical LCD assembly process, the liquid crystal panel or the rear surface of the PCB may be used. The aluminum tape is attached first to shield the EMI, and then the EMI is further shielded by assembling the main body of the notebook PC or the main body of the monitor, that is, the back-light unit with the fixed and placed mold frame. Doing.

However, in the conventional EMI shielding method in which aluminum tape is attached to the back of the liquid crystal panel or the back of the PCB with an EMI shielding film, EMI generated from the back of the LCD can be shielded to some extent. EMI generated from the front surface cannot be shielded, and in particular, since the EMI shielding method for the front surface of the liquid crystal panel is hardly considered, there is a limit to improving the screen quality of the LCD.

Accordingly, the present invention has been made to solve the above problems, to provide an LCD that can effectively shield the EMI generated from the front surface of the liquid crystal panel, an object thereof.

1 is a plan view of a black matrix;

2 is a sectional view schematically showing a part of a liquid crystal panel;

3 is a cross-sectional view schematically showing a liquid crystal display device according to an exemplary embodiment of the present invention.

4 is a cross-sectional view schematically illustrating a liquid crystal display device according to an exemplary embodiment of the present invention.

(Explanation of symbols for the main parts of the drawing)

5: patterned first conductive layer 10: thin film transistor array substrate

11: glass substrate 12: black matrix

15 dot-shaped second conductive layer 20 color filter substrate

30: liquid crystal panel 40: metallic frame chassis

40a: protrusion 50: conductive tape

The LCD of the present invention for achieving the above object is an LCD having a structure for suppressing the EMI emitted to the front surface of the liquid crystal panel, or the incoming EMI, a thin film transistor array substrate and a conductive metal black matrix is provided The color filter substrate is bonded to each other under a liquid crystal layer, and the first conductive layer having a pattern shape formed at one edge of the thin film transistor array substrate and the color filter substrate portion opposite thereto are formed to contact the black matrix. A liquid crystal panel in which a dot-shaped second conductive layer is contacted to electrically connect the substrates; And a metallic frame chassis surrounding the liquid crystal panel to support the liquid crystal panel, wherein the metallic frame chassis and the black matrix of the conductive metal material are electrically contacted.

According to the present invention, the liquid crystal panel is electrically contacted with a metallic frame chassis that surrounds and supports the liquid crystal panel with a black matrix made of a conductive chromium metal film provided on the color filter substrate for the purpose of increasing the contrast ratio of the LCD. The back side of the, of course, can radiate or minimize the EMI to the front, thereby improving the LCD screen quality.

(Example)

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

First, as is well known, the color filter substrate is provided with a black matrix for the purpose of increasing the contrast ratio of the LCD. Such a black matrix is usually formed in a laminated structure with a conductive chromium metal film or a chromium oxide film, and has a form of a mesh grid surrounding each pixel region, as shown in FIG. In FIG. 1, reference numeral 20 denotes a color filter substrate, 11 a glass substrate, 12 a black matrix, and 13 a pixel area.

In addition, as shown in FIG. 2, the color filter substrate 20 having the black matrix 12 may include a thin film transistor array substrate 10 having a thin film transistor (not shown) and a liquid crystal layer (not shown). Are bonded to each other to form a liquid crystal panel 30, wherein one side edge portion of the thin film transistor array substrate 10 and one side edge portion of the color filter substrate 20 opposite to the thin film transistor array substrate 10 are disposed on the substrates 10 and 20. ), The first conductive layer 5 in the form of a pattern and the second conductive layer 15 in the form of dots are provided, respectively, so that electrical connection therebetween is achieved, and they are contacted with each other. In addition, the dot-shaped second conductive layer 15 is also in electrical contact with the black matrix 12 having a mesh grid form.

Therefore, in the exemplary embodiment of the present invention, the black matrix formed of the conductive chromium film is connected to the metallic frame chassis surrounding the liquid crystal panel, so that EMI radiated to the front surface of the liquid crystal panel or incoming EMI can be effectively shielded. Be sure to

4 is a cross-sectional view schematically showing the LCD according to the first embodiment of the present invention.

As shown, the metallic frame chassis 40 surrounds the liquid crystal panel 30 in which the thin film transistor array substrate 10 and the color filter substrate 20 are bonded to each other under the interposition of the liquid crystal layer (not shown). The protrusion 40a is disposed at a predetermined portion of the metallic frame chassis 40, that is, a portion opposed to the patterned first conductive layer 5 formed on the thin film transistor array substrate 10. The protrusion 40a is in electrical contact with the first conductive layer 5 in the pattern form.

In addition, the color filter substrate 20 is formed of a conductive chrome metal film, and is provided with a black matrix 12 having a mesh grid shape, and the black matrix 12 is the color filter substrate 20. Contact with the dot-shaped second conductive layer 15 formed at one edge portion of the substrate), and the second conductive layer 15 is a patterned first conductive layer formed on the thin film transistor array substrate 10. It is in contact with (5).

Thus, the metallic frame chassis 40 and the black matrix 12 are electrically contacted by the first and second conductive layers 5 and 15, and in the LCD having such a structure, the liquid crystal panel 30 EMI radiated to the front of the panel, or the incoming EMI, is shielded by the black matrix 12 in electrical contact with the metallic frame chassis 40.

In addition, as described above, an EMI shielding film such as aluminum tape is formed on the rear surface of the liquid crystal panel 30, and thus the influence of EMI on both the front and rear surfaces of the liquid crystal panel 30 can be suppressed or minimized. So, you can improve the screen quality of the LCD.

On the other hand, in the LCD having the above structure, since the EMI shielding structure is obtained only by providing the metallic frame chassis with the protrusions that can be contacted with the patterned first conductive layer, the change of the existing process line is Without this, it is very simple to shield the EMI at the front and back of the liquid crystal panel.

FIG. 2 is a schematic cross-sectional view of an LCD according to a second embodiment of the present invention, as shown, unlike the previous embodiment in which the projections are provided in the metallic frame chassis in this embodiment, the metallic frame The shape of the chassis 40 is maintained as it is, but the bonding between the metallic frame chassis 40 and the liquid crystal panel 30 is performed using the conductive tape 50, and at the same time, the conductive tape 50 is formed. ) To electrically contact the metallic frame chassis 40 and the first conductive layer 5 in a pattern form formed on the thin film transistor array substrate 10, thereby resulting in the metallic frame chassis ( 40 and the black matrix 12 having a mesh shape of the mesh formed on the color filter substrate 20 is electrically contacted.

As described above, since the present invention uses the black matrix of the mesh grid structure as an EMI shielding film that can radiate to the front surface of the liquid crystal panel or can suppress defects caused by EMI, there is no additional component or process. EMI can be effectively suppressed on the front surface of the liquid crystal panel very easily, thereby improving the screen quality of the LCD.

In addition, this invention can be implemented in various changes within the range which does not deviate from the summary.

Claims (3)

A liquid crystal display device having a structure for suppressing electromagnetic interference emitted to or in front of a liquid crystal panel, A thin film transistor array substrate and a color filter substrate having a black matrix of a conductive metal material are bonded to each other under a liquid crystal layer, and the first conductive layer having a pattern shape formed at one edge portion of the thin film transistor array substrate and facing the same. A liquid crystal panel in which a dot-shaped second conductive layer formed to be in contact with the black matrix is contacted to a portion of the color filter substrate to electrically connect the substrates; And a metallic frame chassis surrounding the liquid crystal panel to support the liquid crystal panel, wherein the metallic frame chassis and the black matrix of the conductive metal material are electrically contacted. Display. The electrical contact between the metallic frame chassis and the conductive matrix black matrix, And a projection provided in the metallic frame chassis so as to be in contact with the first conductive layer in the pattern form. The electrical contact of claim 1 wherein the electrical contact between the metallic frame chassis and the conductive bla matrix is: And a conductive tape in contact with the first conductive layer in the pattern form on the contact surface of the metallic frame chassis and the liquid crystal panel.