JPH11143396A - Liquid crystal display device, gasket to be used for display device and manufacture of gasket - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain stable display quality and a highly reliable liquid crystal display device(LCD) by providing the LCD with a gasket capable of reducing the generation of a radiation noise causing electro-magnetic interference(EMI) and preventing the generation of malfunction in electronic parts arranged on a printed board even when the gasket is brought into contact with the electronic parts. SOLUTION: The upper and lower faces of a gasket 5 on which conductive cloth 6 is arranged are brought into contact with a ground pad on a printed board 2 and a metallic shield frame 1 and electrically connected to the pad and the frame 1 through a conductive member 8 arranged in an insulating member 7. Polyurethane foam 7 to be the insulating member is arranged on the side face of the gasket 5.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a liquid crystal display device and an EMI (Electro Magnetic Interface) of the liquid crystal display device.
The present invention relates to a gasket used as a measure and a method for manufacturing the gasket.

[0002]

2. Description of the Related Art FIG. 3 is a schematic sectional view showing the structure of a conventional liquid crystal display. In the figure, 1 is a metal shield frame, 2 is a printed circuit board attached to the back surface of the liquid crystal panel 11, 3 is an electronic component mounted on the printed circuit board 2 and fixed by solder 4, and 10 is a conductive cloth 6 made of urethane. This is a gasket formed by winding around the home 7. The ground pad (not shown) on the printed circuit board 2 and the metal shield frame 1 connected to the ground are brought into contact with the upper and lower surfaces of the gasket 10 around which the conductive cloth 6 is wound around the urethane platform 7. , The ground of the printed circuit board 2 is strengthened by the electrical connection.
The generation of radiation noise that causes MI is reduced.

[0003]

Since the gasket 10 used in the conventional liquid crystal display device is constructed as described above, the gasket 10 is deformed by the pressure of the metal shield frame 1, and the gasket 10 on the side surface of the gasket 10 is deformed. Sex cloth 6
Then, the electronic components 3 arranged in the vicinity of the periphery of the gasket 10 come into contact with each other and short-circuit, causing a problem that the electronic components 3 may malfunction.

SUMMARY OF THE INVENTION The present invention has been made to solve the above-described problems. The ground of a printed circuit board on which electronic components are mounted is strengthened to reduce the generation of radiated noise causing EMI and to reduce the occurrence of EMI. By providing a gasket that does not cause a malfunction in the electronic component even when it comes into contact with an electronic component disposed on the substrate, a stable display quality is obtained, and a highly reliable liquid crystal display device without a malfunction or the like is obtained. The purpose is to:

[0005]

A gasket according to the present invention comprises: a plurality of elastic insulating members juxtaposed;
A flexible conductive film attached to each part of each insulating member, and each elastic insulating member is connected so as to be electrically connectable via the respective conductive film. Characteristic gasket.

A method of manufacturing a gasket according to the present invention includes a step of winding a flexible conductive film around an elastic insulating member, a step of juxtaposing a plurality of insulating members around which the conductive film is wound, and A step of sequentially bonding the conductive film to the insulating member to be cut, and cut the insulating member around which the bonded conductive film is wound,
The method includes a step of exposing the insulating member. Also,
The insulating member around which the conductive film is wound is bonded with a double-sided adhesive tape.

Further, the liquid crystal display device according to the present invention comprises:
A liquid crystal display element having a liquid crystal material sandwiched between two opposing insulating substrates, a printed circuit board having a drive circuit for the liquid crystal display element, a metal shield frame connected to ground, a printed circuit board and a metal shield It is provided with a gasket that is disposed between the frames and electrically connects the ground pad of the printed circuit board and the metal shield frame by the conductive film being in contact with the ground pad and the metal shield frame on the printed circuit board, respectively. is there.

[0008]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Embodiment 1 Hereinafter, a gasket used in a liquid crystal display device according to an embodiment of the present invention will be described with reference to the drawings. FIG. 1 shows Embodiment 1 of the present invention.
FIG. 2 is a cross-sectional view of a gasket used in a liquid crystal display device according to the present invention. In the drawing, reference numeral 1 denotes a metal shield frame, 2 denotes a driving circuit for a liquid crystal display element, and a printed board attached to the back surface of the liquid crystal panel 11, and 3 denotes an electron mounted on the printed board 2 and fixed by solder 4. Parts 5 and 5 are gaskets, which are a flexible conductive film 6 (conductive cloth in this embodiment) and an elastic insulating member 7.
(A urethane home in the present embodiment). Reference numeral 8 denotes a conductive member that is disposed inside the insulating member 7 and electrically connects the conductive films 6 formed on two opposing surfaces of the insulating member 7. Gasket 5
A conductive cloth 6 is disposed on two opposing surfaces (an upper surface and a lower surface in the present embodiment) of an insulating member (urethane home) 7 having elasticity, and the conductive cloth 6 disposed on the upper surface and the lower surface. Has a structure electrically connected through a conductive member 8 arranged inside the gasket 5. A urethane home 7 which is an insulating member is disposed on a side surface of the gasket 5. The upper and lower surfaces of the gasket 5 according to the present embodiment, on which the conductive cloth 6 is arranged,
By contacting a ground pad (not shown) on a printed board 2 having a drive circuit of a liquid crystal display element with a metal shield frame 1 connected to the ground, the ground pad of the printed board 2 and the metal shield frame 1 are connected. They are electrically connected via the conductive member 8. In addition, a urethane home 7 which is an insulating member is disposed on a side surface of the gasket 5 which may come into contact with the electronic components 3 arranged around the gasket 5 due to deformation of the gasket 5.

According to the present invention, by forming the side surface of the gasket 5 with the insulating member (urethane home) 7, even if the electronic component 3 arranged near the periphery of the gasket 5 comes into contact with the gasket 5, Malfunction of the electronic component 3 can be prevented, and the gasket 5
A conductive cloth 6 is disposed on the upper surface and the lower surface of the device, and is brought into contact with a ground pad (not shown) on a printed circuit board 2 having a driving circuit for a liquid crystal display element and a metal shield frame 1 connected to the ground. By electrically connecting the liquid crystal, the ground of the printed circuit board 2 can be strengthened, the generation of radiation noise that causes EMI can be reduced, a stable display quality can be obtained, and a highly reliable liquid crystal free from malfunction or the like can be obtained. A display device can be obtained.

Embodiment 2 FIG. 2 is a diagram for explaining a method of manufacturing a gasket. In the figure, reference numeral 9 denotes an adhesive material such as a double-sided adhesive tape. The same parts as those in FIG. 1 are denoted by the same reference numerals, and description thereof will be omitted. An adhesive material 9 such as a double-sided adhesive tape is applied (attached) to a side surface of a gasket 10 having the structure shown in the conventional example of FIG. 3 (the conductive cloth 6 is wound around the urethane home 7), and is shown in FIG. By joining the plurality of adjacent gaskets 10 as described above, and then cutting along the line AA, the gasket 5
A conductive cloth 6 electrically connected to each other is disposed on an upper surface and a lower surface, and a gasket 5 having a structure in which a urethane home 7 as an insulating member is disposed on a side surface of the gasket 5. You. According to the present embodiment, gasket 5 can be easily manufactured at low cost.

[0011]

As described above, according to the present invention, the side surface of the gasket 5 disposed between the printed circuit board having the driving circuit of the liquid crystal display element and the metal shield frame is provided with an elastic insulating member (urethane). In the case where the gasket comes into contact with an electronic component disposed near the periphery of the gasket, it is possible to prevent the electronic component from malfunctioning, and to form a conductive film on the upper and lower surfaces of the gasket. (Conductive cloth) is arranged, and the ground pad on the printed circuit board is brought into contact with the metal shield frame connected to the ground, thereby electrically connecting the ground pad of the printed circuit board and the metal shield frame. By strengthening the ground of the printed circuit board, it is possible to reduce the generation of radiated noise that causes EMI. Obtained display quality with it can be unreliable malfunctions like to obtain a high liquid crystal display device. Further, according to the present invention, a gasket can be easily and inexpensively manufactured.

[Brief description of the drawings]

FIG. 1 is a sectional view showing a gasket used in a liquid crystal display device according to a first embodiment of the present invention.

FIG. 2 is a view illustrating a method of manufacturing a gasket according to a second embodiment of the present invention.

FIG. 3 is a sectional view showing a gasket of a conventional liquid crystal display device of this type.

[Explanation of symbols]

1 metal shield frame, 2 printed circuit board, 3 electronic components, 4 solder, 5 gasket, 6 conductive film (conductive cloth), 7 insulating member (urethane home),
8 conductive member, 9 adhesive material (double-sided adhesive tape), 1
1 LCD panel.

Claims (4)

[Claims] A plurality of elastic insulating members arranged side by side, and a flexible conductive film attached to opposing portions of each of the insulating members, wherein each of the insulating members is A gasket, which is electrically connected via respective conductive films. 2. A step of winding a flexible conductive film around an elastic insulating member, arranging a plurality of insulating members around which the conductive film is wound, and forming a conductive member on an adjacent insulating member. A method of manufacturing a gasket, comprising: a step of sequentially bonding films; and a step of cutting an insulating member around which the bonded conductive film is wound to expose the insulating member. 3. The method according to claim 2, wherein the insulating member around which the conductive film is wound is adhered with a double-sided adhesive tape. 4. A liquid crystal display device comprising a liquid crystal material sandwiched between two opposing insulating substrates, a printed circuit board having a driving circuit for the liquid crystal display device, and a metal shield frame connected to ground. The metal pad is disposed between the printed board and the metal shield frame, and the conductive film is in contact with the ground pad and the metal shield frame on the printed board, respectively. A liquid crystal display device comprising the gasket according to claim 1, wherein the gasket is electrically connected.