KR19990068952A - Backlight Unit of Liquid Crystal Display - Google Patents

Abstract

The lower light guide plate is inclined in one direction with respect to the upper light guide plate so as to be spaced apart by a predetermined distance to form a light guide space between the two light guide plates, and has a light irradiation directivity with respect to the inclined direction at wide end portions of the two light guide plates. A backlight unit of a liquid crystal display device is provided.

Therefore, the weight of the product can be reduced in the portable notebook computer and the liquid crystal display device requiring light weight for carrying, and the light efficiency can be improved.

Description

Backlight Unit of Liquid Crystal Display

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a backlight unit of a liquid crystal display, and more particularly, to form a light guide plate spaced apart from an upper light guide plate and a lower light guide plate and to form a light transmission pattern on the upper light guide plate, thereby reducing the weight of a component for a backlight. It is about a unit.

Liquid crystal display devices have been widely used in practical applications such as electronic desk calculators and watches, as well as measuring instruments, office equipment, televisions, and notebook computers. Conventional liquid crystal displays are inconvenient to use in a dark place because they are non-luminescent, and a backlight is devised and applied to compensate for this.

The backlight of the liquid crystal display device has been developed into a direct type and an edge method. However, the edge type is generally used. In the case of the edge type, a light source is formed on both sides or one side to guide light. It is configured to illuminate.

In particular, the backlight unit is a device for irradiating light from the back of the panel, and a fluorescent tube such as a cold cathode ray tube and a hot cathode ray tube is used as a light source, and a light guide plate, a diffusion sheet, a reflective sheet, and the like are composed of components. .

The structure of a conventional backlight unit is disclosed in FIG. 1, and a light source holder 12 having a light source 10 installed therein is configured at one side thereof, and the light source holder 12 has an inner wall reflecting parabolic light. The reflection was configured to be directional with respect to one direction.

The light guide plate 14 is provided on a side surface of the light source holder 12 to which light is irradiated, a reflective sheet 16 is installed below the light guide plate 14, and the diffusion sheet 18 is sequentially disposed on the light guide plate 14. The two light condensing sheets 20 and the protective sheet 22 are laminated and provided.

The light emitted from the light source 10 according to the above-described configuration is directly radiated to the light guide plate 14 or proceeds to the light guide plate 14 after being reflected by the inner wall of the light source holder 12. The light traveling to the light guide plate 14 is reflected by the lower reflector 16 and then continues to move forward or proceeds to the upper diffusion sheet 18 to illuminate the upper part through the light collecting sheet 20 and the protective sheet 22. It is used to

However, the light guide plate of the above-mentioned conventional backlight unit occupies at least four times or ten times more volume than other components, and also accounts for a substantial part of the weight of the entire unit in weight.

Currently, the size of the liquid crystal display device is gradually increasing from small to 12.1 "or 13.3", and in the situation where a module of a larger size is being developed, the light guide plate of the backlight unit is relatively large, especially increasing the weight of the entire product. Acts as.

Accordingly, an object of the present invention is to provide a backlight unit of a liquid crystal display device for reducing the weight specific gravity of the entire product as it is enlarged by improving the structure of the light guide plate to reduce the load by reducing the load.

1 is a cross-sectional view illustrating a backlight unit of a conventional liquid crystal display device.

2 is a cross-sectional view showing a preferred embodiment of a backlight unit of the liquid crystal display according to the present invention.

<Explanation of symbols for main parts of the drawings>

10, 30: light source 12, 32: light source holder

14, 34, 36: Light guide plate 16, 38: Reflective sheet

18, 40: diffusion sheet 20, 42: light collecting sheet

22, 44: protective sheet

In order to achieve the above object, a backlight unit of a liquid crystal display device may have a lower light guide plate disposed at an interval with respect to an upper light guide plate at a predetermined distance to form a light guide space between the two light guide plates. It is provided with the light source which has light irradiation directivity with respect to the said inclination direction in the wide spaced end part.

The upper light guide plate and the lower light guide plate may be coupled to the stepped space by forming upper and lower portions of the end portion in the light irradiation direction of the light source, respectively.

Hereinafter, the features and advantages of the present invention will be described in detail with reference to the accompanying drawings.

Referring to FIG. 2, in the embodiment according to the present invention, a light source holder 32 having a light source 30 installed therein is configured on one side, and the light source holder 32 has an inner wall reflecting parabolic light and has a reflection. Is configured to be oriented in one direction.

On the side of the light source holder 32 to which light is irradiated, a predetermined pattern is formed, and an upper light guide plate 34 serving as a transmissive role and a lower light guide plate 36 performing a front reflection role are installed. The reflective sheet 38 is provided, and the diffusion sheet 40, the two light collecting sheets 42, and the protective sheet 44 are sequentially stacked on the upper light guide plate 34.

In particular, a step that is equal to the thickness of the upper LGP 34 and the lower LGP 36 is formed at one end of the light source holder 32 to which light is irradiated, and one side of the upper LGP 34 and the lower LGP 36 is formed. Is coupled to the above-mentioned stepped portion of the light source holder 32. In addition, the upper light guide plate 34 and the lower light guide plate 36 are disposed such that the lower light guide plate 36 is inclined upward with respect to the upper light guide plate 34 so that the distance from the light guide plate 34 gradually decreases. A space of a predetermined interval is formed between the upper light guide plate 34 and the lower light guide plate 36.

The light emitted from the light source 30 by the above-described configuration is directly or reflected and then proceeds through the space between the upper light guide plate 34 and the lower light guide plate 36 through the side surface of the light source holder 32. The light may be reflected by the reflective sheet 38 below the lower light guide plate 36 to be steered upwards, and conversely, the light may be integrated and irradiated to the upper light guide plate 34 to be steered upwards.

That is, the light emitted from the light source is dispersed in a predetermined pattern of the upper light guide plate 34 and proceeds to the upper diffusion sheet 40, the light collecting sheet 42, and the protective sheet 44.

In the embodiment according to the present invention, since the upper light guide plate 34 and the lower light guide plate 36 are spaced apart to form an air layer, the light transmitting medium is excellent in light transmittance because the medium for passing light is excellent in light transmittance, and accordingly, Excellent

In addition, the embodiment according to the present invention improves only the structure of the light guide plate without changing the structure of the conventional backlight unit, so that unnecessary operations such as unnecessary arrangement changes are unnecessary and efficient, and the load is reduced to a very small amount as compared with the prior art.

As described in detail above, the present invention has been described in detail with respect to preferred embodiments, but those skilled in the art to which the present invention pertains, various embodiments of the present invention without departing from the spirit and scope of the present invention It will be appreciated that the present invention may be modified or modified as described above.

Therefore, according to the present invention, it is possible to reduce the load of the product in a portable notebook computer and a liquid crystal display device requiring light weight for carrying, and also improve the light efficiency.

Claims (2)

The lower light guide plate is inclined in one direction with respect to the upper light guide plate so as to be spaced apart by a predetermined distance to form a light guide space between the two light guide plates, and has a light irradiation directivity with respect to the inclined direction at wide end portions of the two light guide plates. Back light unit of the liquid crystal display device characterized in that it comprises a. The method of claim 1, And forming the upper and lower portions of the end portion of the light source in the light irradiation direction stepwise to couple the upper light guide plate and the lower light guide plate to the stepped space.