CN201310821Y - Light guide plate and backlight module - Google Patents

Abstract

The utility model provides a light guide plate and a backlight module, backlight module includes a light guide plate, an at least light source and an at least bowl. The side of the light guide plate is provided with at least one light incident surface which is an inclined surface. The light source and the reflector are arranged beside the light incident surface, and the reflector surrounds the light source. In addition, the central point of the light source is positioned on the vertical plane of the light incident surface. The light source is, for example, a cold cathode fluorescent lamp or a light emitting diode. The utility model discloses a light guide plate has great light yield.

Description

A light guide plate and a backlight module

technical field

The utility model relates to a light guide plate and a backlight module, in particular to a light guide plate with relatively large light output and a backlight module using the light guide plate.

Background technique

Over the years, with the rapid development of liquid crystal display technology, and the amount of radiation emitted by it is much smaller than that of traditional CRT displays, liquid crystal displays have now become the mainstream of the display market. The backlight module is one of the key components of the liquid crystal display panel. Since the liquid crystal itself does not emit light, the function of the backlight module is to supply sufficient brightness and evenly distributed light source so that it can display images normally. Generally speaking, backlight modules can be divided into two types: side-illuminated and direct-illuminated, and side-illuminated backlight modules are mainly used in small-sized liquid crystal displays, such as desktop computers or notebook computers. LCD Monitor. The main components of the side-illuminated backlight module are a light guide plate and a light tube, wherein the light tube is placed on the side of the light guide plate.

Please refer to FIG. 1 , which is a schematic diagram of a conventional side-illuminated backlight module. The side-illuminated backlight module 100 includes: two reflectors 110 , two lamp tubes 120 , a reflector 130 , a light guide plate 140 and a plurality of optical films 150 . Wherein, the two lamp tubes 120 are respectively arranged on both sides of the light guide plate 140 and covered by the reflector 110, the reflector 130 is arranged under the light guide plate 140, and the optical film 150 is It is arranged above the light guide plate 140 . The light guide plate 140 has two light incident surfaces 141 and a light exit surface 142 , wherein the light incident surface 141 and the light exit surface 142 are perpendicular to each other.

Some of the light emitted by the lamp tube 120 will directly enter the light-incident surface 141 , and other parts of the light will be reflected by the reflector 110 and then enter the light-incident surface 141 . The bottom surface of the light guide plate 140 is coated with a plurality of reflective patterns (not shown), so the light emitted by the lamp tube 120 will be reflected by the reflective patterns after entering the light guide plate 140, so that the light is incident toward the direction of the optical film 150 .

Since current liquid crystal displays are more and more focused on thin and light shapes, the thickness of the light guide plate 140 is also getting thinner and thinner. If the light guide plate 140 is thinner, the area of the light-incident surface 141 is smaller, and the light emitted by the lamp tube 120 is directly incident on the light-incident surface 141. The amount of the glossy surface 141 is larger. However, after the light is reflected by the reflector 110 , part of the energy will be absorbed by the reflector 110 . In this way, the less the amount of light incident on the light-incident surface 141 is, the lower the amount of light emitted from the light-emitting surface 142 of the light guide plate 140 is.

Therefore, how to reduce the thickness of the light guide plate while maintaining a certain amount of light is worthy of consideration by those skilled in the art.

Contents of the invention

The main purpose of the utility model is to provide a light guide plate and a backlight module using the light guide plate, and the light guide plate has a relatively large light output.

In order to achieve the above and other objectives, the utility model provides a backlight module, which includes: a light guide plate, at least one light source and at least one reflector. The side of the light guide plate has at least one light incident surface, and the light incident surface is an inclined surface. Wherein, both the light source and the reflection cover are arranged beside the light incident surface, and the reflection cover surrounds the light source. In addition, the center point of the light source is, for example, located on the vertical plane of the light incident surface.

In the above backlight module, the light source is a cold cathode fluorescent lamp or a light emitting diode.

In the above-mentioned backlight module, a diffusion film is further included, and the diffusion film is located above the light guide plate.

In the above-mentioned backlight module, a brightness enhancement film is further included, and the brightness enhancement film is located above the diffusion film.

In the above-mentioned backlight module, there are two light incident surfaces, which are respectively located on opposite sides of the light guide plate.

In the above-mentioned backlight module, a reflective sheet is further included, and the reflective sheet is arranged under the light guide plate.

In order to achieve the above and other objectives, the utility model provides a light guide plate, the side of which has at least one light incident surface, and the light incident surface is an inclined surface.

Compared with the prior art, since the light guide plate of the present invention has an inclined light incident surface, the light incident surface has a larger area than the existing light guide plate. Therefore, compared with the existing light guide plate, the amount of light emitted by the light source directly incident on the light-incident surface is larger, while the amount reflected by the reflector and then incident on the light-incident surface is smaller. Therefore, compared with the existing light guide plate, the light output surface of the light guide of the present invention has a larger light output.

In order to make those of ordinary skill in the art understand the purpose, features and effects of the utility model, the utility model will be described in detail as follows through the following specific examples and accompanying drawings.

Description of drawings

FIG. 1 is a schematic diagram of an existing side-illuminated backlight module;

FIG. 2 is a schematic diagram of a backlight module according to a first embodiment of the present invention;

FIG. 3 is a schematic diagram of a backlight module according to a second embodiment of the present invention;

FIG. 4 is a schematic diagram of a backlight module according to a third embodiment of the present invention.

Explanation of reference numerals: prior art: 100-backlight module; 110-reflector; 120-lamp tube; 130-reflector; 140-light guide plate; 141-light incident surface; The utility model: 200, 300-backlight module; 210, 310-reflector; 220, 320-light source; 322-printed circuit board; 230, 330-reflector; 240, 340-light guide plate; 241a-vertical surface; 242-light-emitting surface; 343-bottom surface; 250, 350-optical film; 251, 351-diffusion film; 252, 352-brightness enhancement film; θ-angle.

Detailed ways

The above-mentioned and other technical features and advantages of the present utility model will be described in more detail below in conjunction with the accompanying drawings.

Please refer to FIG. 2 first. FIG. 2 is a schematic diagram of a backlight module according to a first embodiment of the present invention. The backlight module 200 includes: two reflectors 210 , two light sources 220 , a reflector 230 , a light guide plate 240 and a plurality of optical films 250 . Wherein, the above-mentioned two light sources 220 are respectively arranged on both sides of the light guide plate 240 and covered by the reflector 210, the reflector 230 is arranged under the light guide plate 240, and the optical film 250 is arranged above the light guide plate 240 . The light guide plate 240 has two light incident surfaces 241 and a light exit surface 242 , wherein the light incident surface 241 is an inclined surface, and an included angle θ exists between the light incident surface 241 and the light exit surface 242 . Wherein, some of the light emitted by the light source 220 will directly enter the light-incident surface 241, and other parts of the light will be reflected by the reflector 210 and then enter the light-incident surface 241.

The bottom of the light guide plate 240 is coated with a plurality of reflective patterns (not shown), so the light emitted by the light source 220 will be reflected by the reflective patterns after entering the light guide plate 240, so that the light is directed toward the light-emitting surface 242 shoot out. The optical film 250 includes a diffusion film 251 and a brightness enhancement film 252 , the diffusion film 251 can diffuse the light more uniformly, and the brightness enhancement film 252 is used to gather the diffused light to increase the brightness. In addition, the light leaked from the bottom of the light guide plate 240 will be reflected by the reflective sheet 230 and enter into the light guide plate 240 again. In addition, the function of the reflector 210 is to allow the light emitted by the light source 220 to be emitted toward the direction of the light guide plate 240 .

Please compare FIG. 1 with FIG. 2 , since the light incident surface 241 is an inclined surface, the area of the light incident surface 241 of the light guide plate 240 is larger than the area of the light incident surface 141 of the light guide plate 140 . Therefore, compared with the light guide plate 140 , the amount of the light emitted by the light source 220 directly entering the light incident surface 241 is larger, while the amount reflected by the reflector 210 and then entering the light incident surface 241 is smaller. Therefore, compared with the light-emitting surface 142 of the light-guiding plate 140 , the light-emitting surface 242 of the light-guiding plate 240 has a larger light output. According to the simulation results, if the included angle θ is 30 degrees and other conditions are the same, the amount of light emitted by the light emitting surface 242 is about twice that of the light emitting surface 142 .

Those skilled in the art can adjust the above-mentioned included angle θ according to the situation. If the included angle θ is smaller, the area of the light-incident surface 241 is larger, and the amount of light output from the light-emitting surface 242 is also larger. In addition, the above-mentioned center point of the light source 220 is located on the vertical plane 241 a of the light incident surface 241 , but those skilled in the art can also adjust the position of the light source 220 according to the situation.

In addition, the above-mentioned light source 220 is a cold cathode fluorescent lamp (Cold Cathode Fluorescent Lamp), but those skilled in the art can replace it with a light emitting diode (Light Emitting Diode). Please refer to FIG. 3 , which is a schematic diagram of a backlight module according to a second embodiment of the present invention. In FIG. 3, the same elements as those of the first embodiment will be marked with the same symbols and will not be described again. In this embodiment, the light source 320 is a light emitting diode and is soldered on a printed circuit board 322 .

In the above-mentioned embodiment, the light incident surface 241 is disposed on both sides of the light guide plate 240 , but those skilled in the art may also only provide the light incident surface on one side. Please refer to FIG. 4 , which is a schematic diagram of a backlight module according to a third embodiment of the present invention. The backlight module 300 includes: a reflector 310 , a light source 320 , a reflector 330 , a light guide plate 340 and a plurality of optical films 350 . The optical film 350 includes a diffusion film 351 and a brightness enhancement film 352 . Wherein, the bottom surface 343 of the light guide plate 340 is an inclined surface inclined from the bottom right to the top left, and the reflection sheet 330 is disposed below the bottom surface 343 . The light incident surface 341 is only disposed on one side of the light guide plate 340 , and the reflector 310 and the light source 320 are disposed beside the light incident surface 341 .

To sum up, since the light guide plate of the present invention has an inclined light incident surface, the light incident surface has a larger area than the conventional light guide plate. Therefore, compared with the existing light guide plate, the amount of light emitted by the light source directly incident on the light-incident surface is larger, while the amount reflected by the reflector and then incident on the light-incident surface is smaller. Therefore, compared with the existing light guide plate, the light output surface of the light guide of the present invention has a larger light output.

The above description is only illustrative of the present utility model, rather than restrictive. Those of ordinary skill in the art understand that many modifications, changes, or Equivalent, but all will fall within the protection scope of the present utility model.

Claims (10)

1. A backlight module, characterized in that it comprises: A light guide plate, the side of which has at least one light incident surface, and the light incident surface is an inclined surface; at least one light source arranged beside the light incident surface; and At least one reflector is arranged beside the light incident surface and surrounds the light source. 2 . The backlight module according to claim 1 , wherein the central point of the light source is located on a vertical plane of the light incident surface. 3 . 3. The backlight module according to claim 1, wherein the light source is a cold cathode fluorescent lamp. 4. The backlight module according to claim 1 or 2, wherein the light source is a light emitting diode. 5. The backlight module according to claim 1 or 2, further comprising a diffusion film, the diffusion film is located above the light guide plate. 6. The backlight module according to claim 5, further comprising a brightness enhancement film, the brightness enhancement film is located above the diffusion film. 7. The backlight module according to claim 1 or 2, wherein there are two light incident surfaces, which are respectively located on opposite sides of the light guide plate. 8. The backlight module according to claim 1 or 2, further comprising a reflective sheet disposed under the light guide plate. 9. A light guide plate, the side of which has at least one light-incident surface, characterized in that the light-incident surface is an inclined surface. 10 . The light guide plate according to claim 9 , wherein there are two light incident surfaces, which are respectively located on opposite sides of the light guide plate. 11 .

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