JPH10268303A - Surface light source device for liquid crystal display device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To improve the reliability of a surface light source device for transmission type liquid crystal display device by preventing a lead wire of a lamp unit constituting the surface light source device from being broken. SOLUTION: The lamp unit 11 consists of a fluorescent lamp 112, rubber holes 21 and 22 fitted to both the ends of the fluorescent lamp 12, a lead wire 13 connected to one end side of the fluorescent lamp 12, an earth wire connected to the other end side of the fluorescent lamp 12, a connector 15 connected to the tips of the lead wire 13 and earth wire 14, etc. The lamp unit 11 is stored inside one side of a frame 17 and fixed to the frame 17 through the rubber holders 21 and 22. The lead wire 13 and earth wire 14 are led out of a corner of the frame 17 and connected to an AC power source through the connector 15. The length of the lead wire 13 led out of the corner of the frame 17 is shorter than the length of the earth wire 14 lead out of the same corner.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a surface light source device of a transmission type liquid crystal display device, and more particularly to a structure of a lamp unit used as a light source of the surface light source device.

[0002]

2. Description of the Related Art In a transmissive liquid crystal display device, a surface light source device is a lamp unit composed of a fluorescent tube as a light source and its wiring, and diffuses light emitted from the fluorescent tube in a plane on the back surface of a display substrate. A light guide plate, a plurality of sheets disposed between the light guide plate and the display substrate for uniformly dispersing light, and a frame for accommodating these sheets.

FIG. 2 shows an outline of a conventional surface light source device.
2A shows the outline of the surface light source device, and FIG. 2B shows the configuration of the lamp unit. The surface light source device 30 includes a frame 17, a lamp unit 31, a light guide plate 18, and the like. The lamp unit 31 is arranged along one side of the frame 17, and the light guide plate 18 is arranged at the center of the frame 17.

The lamp unit 31 includes a fluorescent tube 12, plastic rubber holders 21 and 22 attached to both ends of the fluorescent tube 12, a lead wire 33 connected to one end of the fluorescent tube 12, and the other end of the fluorescent tube 12. , A lead wire 33, a connector 15 connected to the end of the ground wire 14, and the like. The lamp unit 31 is housed inside one side of the frame 17 and is fixed to the frame 17 via rubber holders 21 and 22. The lead wiring 33 and the ground wiring 14 are connected to the frame 1
7 is pulled out to the outside from a corner and is connected to an AC power supply via a connector 15.

(Problems of the conventional surface light source device) In the conventional surface light source device 30, as shown in FIG.
1 lead wire 33 and ground wire 14
The lengths of the portions L drawn out from the corners are the same. As described above, if the lengths of the two wirings drawn from the corners of the frame 17 are the same, when the connector 15 is connected to an external AC power supply, depending on the orientation of the connector 15, one of the two wirings may be used. Tensile stress is applied to one of them, which easily causes disconnection. If the lead wiring 33 is disconnected, a high voltage is applied to the lead wiring 33, which is dangerous, and there is also a risk of ignition due to sparks. For this reason, the conventional lamp unit has a problem regarding its reliability.

[0006]

SUMMARY OF THE INVENTION The present invention has been made in view of the above-mentioned problems of the conventional lamp unit.
SUMMARY OF THE INVENTION It is an object of the present invention to prevent disconnection of a lead wire of a lamp unit constituting a surface light source device and improve reliability of the lamp unit in a surface light source device of a transmission type liquid crystal display device.

[0007]

A surface light source device of a liquid crystal display device according to the present invention comprises a frame, a lamp unit arranged along at least one side of the frame, and a lamp unit arranged at the center of the frame and irradiated from the lamp unit. In a surface light source device of a liquid crystal display device including a light guide plate that diffuses the reflected light in a plane, the lamp unit includes a linear light-emitting body,
A lead wire connected to one end of the light emitting body and drawn out from the corner of the frame, and an earth wire connected to the other end of the light emitting body and drawn out together with the lead wire from the corner of the frame; A connector connected to the leading ends of the lead wiring and the ground wiring, and connecting the lead wiring and the ground wiring to an external AC power supply, wherein the length of the lead wiring pulled out from the corner of the frame is the length of the frame. It is characterized in that it is longer than the length of the ground wire drawn from the corner.

According to the surface light source device of the present invention, the length of the lead wire extending from the corner of the frame and reaching the connector is also longer than the length of the ground wiring extending from the same corner of the frame and reaching the connector. This makes it difficult for tensile stress to act on the lead wiring side, so that the risk of disconnection of the lead wiring is reduced, and the reliability of the lamp unit is improved.

[0009]

FIG. 1 shows an outline of a surface light source device according to the present invention. FIG. 1a shows an outline of a surface light source device, and FIG.
Indicates the configuration of the lamp unit. Surface light source device 10
Is a frame 17, a lamp unit 11, and a light guide plate 18.
Etc. The lamp unit 11 is arranged along one side of the frame 17, and the light guide plate 18 is
7 is arranged at the center.

The lamp unit 11 includes a fluorescent tube 12 (light emitting body), plastic rubber holders 21 and 22 attached to both ends of the fluorescent tube 12, a lead wire 13 connected to one end of the fluorescent tube 12, and a fluorescent tube 12. Wiring 14, lead wiring 13 and ground wiring 14 connected to the other end of the
And a connector 15 connected to the distal end of the connector. The lamp unit 11 is housed inside one side of the frame 17, and is inserted into the frame 17 via rubber holders 21 and 22.
It is fixed to. Lead wiring 13 and ground wiring 14
Is drawn out from the corner of the frame 17 and connected to an AC power supply (not shown) via the connector 15.

Here, the lamp unit 11 shown in FIG.
In this case, the length of the lead wiring 13 extending from the corner of the frame 17 to the connector 15 is similarly set to the length of the ground wiring 14 extending from the same corner of the frame 17 to the connector 15.
Is configured to be longer than the length L.

As described above, the lead wires 13 drawn from the corners of the frame are similarly drawn from the same corner of the frame and made longer than the ground wires 14, so that tensile stress is less likely to act on the lead wires 13 side. Therefore, the risk of disconnection of the lead wiring 13 is reduced, and the reliability of the lamp unit 11 is improved.

[0013]

According to the surface light source device of the present invention, a tensile stress is less likely to act on the lead wiring side of the lamp unit, so that the risk of disconnection of the lead wiring is reduced and the reliability of the lamp unit is improved. I do. Further, according to the surface light source device of the present invention, since there is no special change in the structure on the frame side, it can be implemented at low cost and a great effect can be obtained.

[Brief description of the drawings]

FIG. 1 is a view schematically showing a surface light source device according to the present invention, FIG. 1A is a perspective view of the surface light source device, and FIG. 1B is a perspective view of a lamp unit.

FIG. 2 is a diagram showing an outline of a conventional surface light source device, FIG. 2A is a perspective view of the surface light source device, and FIG. 2B is a perspective view of a lamp unit.

[Explanation of symbols]

10: Surface light source device, 11: Lamp unit, 1
2 ... fluorescent tube (light emitting body), 13 ... lead wiring, 1
4 ... ground wiring, 15 ... connector, 17 ...
Frame, 18: Light guide plate, 21: Rubber holder,
22: rubber holder, 30: surface light source device, 31
..Lamp unit, 33 ... lead wiring.

Claims (1)

[Claims] 1. A liquid crystal display comprising: a frame; a lamp unit disposed along at least one side of the frame; and a light guide plate disposed at the center of the frame and diffusing light emitted from the lamp unit in a plane. In the surface light source device of the device, the lamp unit includes a linear illuminant, a lead wire connected to one end of the illuminant, and a lead wire drawn outside from a corner of the frame, and connected to the other end of the illuminant. A ground wire extending to the outside together with the lead wire from the corner of the frame; and a connector connected to the leading ends of the lead wire and the ground wire for connecting the lead wire and the ground wire to an external AC power supply; The length of the lead wire drawn from the corner of the frame is longer than the length of the ground wire drawn from the corner of the frame. The surface light source device of the liquid crystal display device that.