CN1619373A - Light guide plate and backlight module - Google Patents

Abstract

A light guide plate includes a light incident surface, a light exit surface adjacent to the light incident surface and a bottom surface opposite to the light exit surface, and the light exit surface is provided with concentric grooves with varying pitches.

Description

Light guide plate and backlight module

【Technical field】

The invention relates to a light guide plate and a backlight module using the light guide plate.

【Background technique】

Liquid crystal display devices are mainly used in various information, communication, and consumer products, such as personal computers, LCD TVs, mobile phones, video phones, and PDAs. Because the liquid crystal display panel itself cannot emit light, it needs a backlight module to provide it with uniform plane light, so as to obtain a good visual effect.

Please refer to FIG. 1 , which is a prior art backlight module disclosed in US Patent No. 5,548,670 issued on August 20, 1996. The backlight module 1 includes light sources 101 and 102 arranged parallel to each other, a light guide plate 12 arranged between the light sources 101 and 102, a reflector 13 arranged below the light guide plate 12, and a prism located above the light guide plate 12. slice 14. In the backlight module 1 , since the light guide plate 12 does not have the function of concentrating light, in order to improve the light output brightness of the backlight module 1 , a prism sheet 14 needs to be used, which increases the cost of the backlight module 1 . In addition, because the prism sheet 14 is used, the light emitted from the light sources 101 and 102 must pass through the prism sheet, which increases the loss of light energy and reduces the light utilization efficiency of the backlight module.

【Content of invention】

In order to overcome the disadvantages of high cost and low light utilization rate of the light guide plate in the prior art, the present invention provides a light guide plate with low cost and high light utilization rate.

In order to overcome the disadvantages of high cost and low light utilization rate of the prior art backlight module, the present invention provides a backlight module with low cost and high light utilization rate.

The technical solution adopted by the present invention to solve the technical problem is: a light guide plate, including a light incident surface, a light exit surface adjacent to the light incident surface, and a bottom surface opposite to the light exit surface. concentric grooves.

The technical solution adopted by the present invention to solve the technical problem is: a backlight module, including a light source and a light guide plate, the light guide plate includes a light incident surface, a light exit surface adjacent to the light incident surface, and a light exit surface connected to the light exit surface. On the bottom surface opposite to each other, the light source is arranged opposite to the light-incident surface, and concentric grooves with varying pitches are arranged on the light-exit surface.

Compared with the prior art, the beneficial effect of the present invention is: grooves are provided on the light-emitting surface of the light guide plate, the prism sheet and the gluing process of the prism sheet and the light guide plate can be omitted, components are reduced, the manufacturing process is simplified, and light rays passing through the adhesive layer are avoided. light energy loss. In addition, because the groove is a concentric structure, it can enhance the light concentrating effect in all directions, save the cost of the prism sheet, and improve the brightness of the light output, so that the light guide plate and the backlight module have the advantages of low cost and high light utilization rate .

【Description of drawings】

FIG. 1 is a perspective view of a prior art backlight module.

Fig. 2 is a side view of the first embodiment of the backlight module of the present invention.

3 is a top view of the light guide plate of the first embodiment of the backlight module of the present invention.

FIG. 4 is a top view of the light guide plate of the second embodiment of the backlight module of the present invention.

【Detailed ways】

Please refer to FIG. 2 and FIG. 3 together, which are respectively a side view and a top view of the light guide plate of the first embodiment of the backlight module of the present invention. The backlight module 2 includes a light guide plate 20 and two light sources 21 . The light guide plate 20 is flat, and its material can be acrylic resin, polycarbonate, polyethylene resin or glass. The light guide plate 20 includes two opposite light incident surfaces 22 , a light exit surface 23 adjacent to the two light incident surfaces 22 , and a bottom surface 24 opposite to the light exit surfaces 23 . Wherein, the light-emitting surface 23 is provided with concentric circular grooves 26 with varying pitches. The concentric circular grooves 26 are concentric circular structures formed by gradually spreading outward from the center of the light guide plate 20, wherein the cross-section of each groove is V It can also be trapezoidal, arc-shaped, elliptical, etc. The concentric circular groove 26 can be integrally injection molded with the light guide plate 20 , and can also be manufactured by chemical etching, laser direct writing and precision mechanical scribing. The bottom surface 24 is provided with a plurality of network points 25, and the size of the plurality of network points 25 is arranged in increments along the direction away from the light incident surface 22. The closer to the light source, the smaller the size and the sparser the distribution; the farther away from the light source, the larger the size and the distribution. The denser it is. The two light sources 21 are respectively disposed opposite to the two light incident surfaces 22 of the light guide plate 20 .

The light is emitted from the two light sources 21 , enters the light guide plate 20 through the light incident surface 22 , is scattered and reflected by multiple dots 25 on the bottom surface 24 , and finally reaches the light exit surface 23 . Because the light-emitting surface 23 is provided with concentric circular grooves 26 with varying pitches, it can gather light in various directions, function as a prism sheet, and improve the brightness of light-emitting. The density of the concentric circular grooves 26 can be changed according to specific requirements, such as linear distribution, polynomial distribution, trigonometric function distribution, etc. can be designed.

Please refer to FIG. 4 , which is a top view of the light guide plate of the second embodiment of the backlight module of the present invention. This embodiment is roughly the same as the first embodiment, except that the concentric grooves are concentric elliptical grooves 36, which are formed by gradually spreading out from the center of the light guide plate, and the concentric elliptical grooves The density of 36 can be changed according to specific requirements, such as linear distribution, polynomial distribution, trigonometric function distribution, etc. can be designed.

The light guide plate and the backlight module of the present invention are not limited to the above-mentioned structures, for example: in order to match different light source positions, the shape of the light guide plate can also be wedge-shaped or triangular; the multiple dots distributed on the bottom surface can be circular or square , rhombus, ellipse or other shapes, the plurality of dots can be protruding or concave, which can be made on the bottom surface by printing or injection molding; the light source can be a cold cathode fluorescent lamp or a light emitting diode.

Claims (8)

1. A light guide plate, comprising a light incident surface, a light exit surface adjacent to the light incident surface, and a bottom surface opposite to the light exit surface, characterized in that: the light exit surface is provided with concentric grooves with varying pitches. 2. The light guide plate according to claim 1, wherein the grooves are concentric circles or concentric ellipses. 3. The light guide plate according to claim 1, characterized in that: the cross section of the groove is V-shaped, trapezoidal, arc-shaped or elliptical. 4. The light guide plate according to claim 1, wherein the groove and the light guide plate are integrally injection molded. 5. The light guide plate according to claim 1, characterized in that: the light guide plate is flat, wedge-shaped or triangular. 6. The light guide plate according to claim 1, characterized in that: the bottom surface is further provided with a plurality of dots, and the dots may be in the shape of a circle, a square, a rhombus or an ellipse. 7. A backlight module, comprising a light source and a light guide plate, the light guide plate comprises a light incident surface, a light exit surface adjacent to the light incident surface and a bottom surface opposite to the light exit surface, the light source is opposite to the light exit surface The light-incident surface is provided, and the feature is that: the light-exit surface is provided with concentric grooves with varying pitches. 8. The backlight module according to claim 7, wherein the light source is a cold cathode fluorescent lamp or a light emitting diode.

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