CN101118341A - Backlight module - Google Patents

Abstract

A backlight module comprises a shell, a plurality of point light sources, a diffusion plate and a plurality of convex light homogenizing units; wherein, a plurality of point light sources set up in the casing with the array mode, and every pointolite has first center, and the diffuser plate sets up in these pointolites top, and the even light unit of a plurality of arch sets up on the diffuser plate is towards the surface of pointolite with the array mode, and every even light unit is corresponding with every pointolite, can go out the light behind the strongest central beam homodisperse in pointolite through setting up of even light unit to improve the degree of consistency of light-emitting.

Description

Backlight module

technical field

The invention relates to a backlight module, in particular to a backlight module capable of emitting light uniformly.

Background technique

In recent years, due to the continuous improvement of the luminous efficiency of light-emitting diodes, light-emitting diodes have gradually replaced fluorescent lamps and incandescent lamps in some fields. For example, backlight modules used in liquid crystal displays use light-emitting diodes as light sources. Common configurations of light sources in the backlight module include direct type and side-edge type. In the direct-lit backlight module, the light source is placed directly under the liquid crystal panel, and in the edge-lit backlight module, the light source is placed on the side below the liquid crystal panel.

Please refer to FIG. 1 , a known backlight module 10 includes a casing 16 , a plurality of LED light sources 11 , a reflector 15 , a diffusion plate 12 and an optical material layer 13 . The light sources 11 are equidistantly arranged in the casing 16 in an array, and the reflection sheet 15 is pasted on the inner surface of the casing 16 to reflect the light provided by the light source 11 to the diffusion plate 12. The diffusion plate 12 is a flat type diffusion plate. 12 and the optical material layer 13 are disposed above the light source 11 in sequence, so that the light provided by the light source 11 can be emitted uniformly.

However, the central point of the LED light source 11 has the strongest luminance, and the luminance gradually decreases from the central point in a concentric circle radially outward. Generally, the luminance of the edge is about half of the central point luminance. After the light passes through the diffusion plate 12 , the central point will still be brighter, making it impossible for the backlight module to emit light uniformly. The current solution is to increase the overall thickness of the diffuser plate 12 to strengthen the effect of dispersing light, so as to improve the uniformity of light emission, but this will result in higher cost, increased light loss and overall thickness.

Contents of the invention

An object of the present invention is to provide a backlight module, which can improve the uniformity of light emitted by a point light source.

In order to achieve the above object, the backlight module of the present invention includes a casing, several point light sources, a diffuser plate and several raised uniform light units; wherein, several point light sources are arranged in the casing in an array, and each point light source There is a first center, the diffusion plate is arranged above these point light sources, and several raised dodging units are arranged in an array on the surface of the diffusion plate facing the point light sources, and each dodging unit corresponds to each point light source, through The setting of the uniform light unit can evenly disperse the central beam with the strongest light intensity in the point light source and then emit light, so as to improve the uniformity of the light output.

Preferably, the point light source is a light emitting diode.

Preferably, the uniform light unit is made of the same material as that of the diffusion plate.

Preferably, several diffusing particles are arranged in the uniform light unit.

Preferably, a connection surface between the light homogenizing unit and the diffusion plate is circular, and the second center and the center of the circle are located on the line connecting the second center and the first center.

Preferably, the light homogenizing unit is integrally formed with the diffuser plate.

Preferably, the point of the dodging unit closest to the point light source is located on the line connecting the first center and the second center.

Preferably, the light homogenizing unit includes a connecting surface flatly attached to the diffuser plate and an arc surface surrounding the connecting surface.

Preferably, the homogenization unit can be a semi-spherical or pyramidal structure.

Description of drawings

FIG. 1 is a side view of a known direct-lit backlight module.

FIG. 2 is a side view of the backlight module of the present invention.

FIG. 3 is a schematic diagram of a diffusion plate of a backlight module of the present invention.

Description of main component symbols

10 direct type backlight module

11 LED light source

12 diffuser plate

13 optical material layer

15 Reflectors

16 Shell

100 backlight modules

101 point lights

102 Diffusion plate

1021 surface

103 uniform light unit

1031 connection surface

1032 curved surface

104 diffuse particles

106 Shell

Q1 First Center

Q2 Second Center

L1 first beam

L2 second beam

A half light intensity angle

Detailed ways

Referring to FIG. 2 , the backlight module 100 of the present invention includes a housing 106 , at least one light source 101 and a diffusion plate 102 . The point light sources 101 are arranged in the housing 106 in an array, and the point light sources 101 can be light emitting diodes. The diffuser plate 102 is arranged above the light source 101 to homogenize the light from the point light source 101 before emitting light, and the surface 1021 of the diffuser plate 102 facing the point light source 101 is provided with at least one raised dodging unit 103, each dodging unit 103 corresponds to each point light source 101 , that is, each point light source 101 is disposed directly under the corresponding light uniformity unit 103 , and the light uniformity unit 103 is disposed on the diffuser plate 102 in an array. The uniform light unit 103 is made of the same material as the diffuser plate 102 . Please refer to FIG. 3 , the protruding uniform light unit 103 includes a connection surface 1031 flatly attached to the diffuser plate 102 and an arc surface 1032 surrounding the connection surface 1031 . The point light source 101 has a first center Q1, and the homogenization unit 103 has a second center Q2, wherein the second center Q2 is located directly above the first center Q1, the first center Q1 is the position where the point light source 101 emits the strongest light, and the second center Q2 is located directly above the first center Q1. The center Q2 is the geometric center of the dodging unit 103 , and the point of the dodging unit 103 closest to the point light source is located on the line connecting the first center Q1 and the second center Q2 . Please refer to FIG. 3 , in this embodiment, the connection surface 1031 of the light homogenizing unit 103 is circular, and the center of the circle is located on the connecting line between the first center Q1 and the second center Q2 . For example, the uniform light unit 103 can be integrally formed with the diffusion plate 102 . In addition, the contact area (that is, the area of the connection surface) between the uniform light unit 103 and the diffuser plate 102 may be approximately equal to the area of the point light source 101 irradiated on the diffuser plate 102 . Wherein, the uniform light unit 103 may be a semi-spherical or pyramidal structure.

In this embodiment, light-emitting diodes are used for illustration. The light beam emitted from the center point of the point light source 101 is the first light beam L1 (i.e. the most luminous light beam), and the second light beam L2 is emitted from the edge of the point light source 101, and the light intensity of the second light beam L2 is about that of the first light beam L1 half. Wherein, the included angle between the second light beams L2 on both sides is the half-light intensity angle A, and the light-emitting area within the half-light intensity angle A is the part where the point light source 101 mainly emits light. The light beam of the light source 101 within the range of the half-light intensity angle A increases the degree of diffusion after passing through the convex uniform light unit 103 on the arc surface, that is to say, after the stronger light passes through the light uniform unit 103, it has a stronger light scattering effect , to homogenize the strong light and emit light.

In addition, in the present invention, the second center Q2 of the uniform light unit 103 on the diffuser plate 102 is aligned directly above the first center Q1 of the light source 101, so that the central point where the light output of the light source 101 is the strongest has the best light uniform effect , where a plurality of diffusing particles 104 can also be arranged in the dodging unit 103, and the degree of convexity of the curved surface of the dodging unit 103 can have different curvature radii according to design requirements. Preferably, it can be designed according to the luminance distribution of the point light source 101 , so that the convexity of the arc surface is proportional to the luminance of the light source 101 .

The backlight module of the present invention utilizes uniformly arranged arc-protruded uniform light units on the surface of the diffuser plate facing the light source, which can effectively disperse the central beam with the strongest light intensity evenly before emitting light.

The above is only used to illustrate the preferred embodiments of the present invention for convenience, the scope of the present invention is not limited to these preferred embodiments, any changes made in the present invention, without departing from the spirit of the present invention, all belong to the application of the present invention patent scope.

Claims (9)

1. backlight module comprises:

Housing;

The some spots light source is arranged in this housing with array way, and each pointolite has first center, and this first center is this strongest position of pointolite bright dipping;

Diffuser plate is arranged at these pointolite tops; And

The even light unit of several projectioies, be arranged at this diffuser plate on the surface of this pointolite with array way, and each even light unit is corresponding with each pointolite, and each should have second center in even light unit, and this second be centered close to this first center directly over.

2. backlight module as claimed in claim 1, wherein this pointolite is a light emitting diode.

3. backlight module as claimed in claim 1 wherein should be spared the light unit by constituting with the diffuser plate identical materials.

4. as claim 1 or 3 described backlight modules, wherein should in the even light unit several diffusion particles be set.

5. backlight module as claimed in claim 1, the joint face that wherein should spare light unit and this diffuser plate is rounded, and the center of circle of this second center and circle is positioned on the line at this second center and this first center.

6. backlight module as claimed in claim 1, wherein this even light unit and this diffuser plate are one-body molded.

7. backlight module as claimed in claim 1 wherein should even light unit be positioned on the line at this first center and second center near the point of this pointolite.

8. backlight module as claimed in claim 1 wherein should comprise smooth in the joint face of diffuser plate and the cambered surface of surrounding this joint face in even light unit.

9. backlight module as claimed in claim 1 wherein should can be semicircle sphere or pyramidal shaped structures in even light unit.

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