Backlight module

• US 7,377,678 B2
• Filed: 05/27/2005
• Issued: 05/27/2008
• Est. Priority Date: 02/16/2005
• Status: Active Grant

• Current Assignee: AUO Corp.
• Original Assignee: AU Optronics Corporation
• Inventors: Chen, Chih-Kuang, Kao, Ko-Chia, Huang, Jyh-Haur
• Primary Examiner(s): Sember; Thomas M.
• Application Number:
  US11/138,405
• Publication Number:
  US 20060181898A1
• Time in Patent Office: 1,096 Days
• Field of Search: 362/608, 362/609, 362/621, 362/622, 362/600, 362/632, 362/634, 362/23, 362/26, 362/623, 362/625, 362/626, 362/298, 362/346
• US Class Current: 362/608
• CPC Class Codes: G02B 6/0026 Wavelength selective element, sheet or layer, e.g. filter or grating
• CPC Class Codes: G02B 6/003 Lens or lenticular sheet or layer
• CPC Class Codes: G02B 6/0031 Reflecting element, sheet or layer
• CPC Class Codes: G02B 6/0046 Tapered light guide, e.g. wedge-shaped light guide
• CPC Class Codes: G02B 6/0051 Diffusing sheet or layer
• CPC Class Codes: G02B 6/0053 Prismatic sheet or layer; Brightness enhancement element, sheet or layer
• CPC Class Codes: G02B 6/0068 Arrangements of plural sources, e.g. multi-colour light sources

Abstract

A backlight module including a diffuser, a reflector, a side light source, a prism lens and a TIR (total internal reflection) lens is disclosed. The reflector is disposed under the diffuser. The side light source is disposed on a side between the diffuser and the reflector. The prism lens is disposed between the side light source and the reflector. The TIR lens is disposed on a bottom of the diffuser and adjacent to the side light source.

Claims

1. A backlight module, comprising:

a diffuser;

a reflector disposed under the diffuser;

a side light source with a bottom for emitting light disposed on a side between the diffuser and the reflector, wherein the reflector extends to a bottom plane of the module from the bottom of the side light source and there is an elevation angle between the reflector and the bottom plane so that the light emitted from the side light source reflected by the reflector travels along a direction nearly parallel to the elevation angle;

a prism lens disposed between the side light source and the reflector;

wherein the prism lens further comprises;

a main body; and

a plurality of protruding parts formed on the main body and facing the side light source, wherein each of the protruding parts has a first plane substantially parallel to the diffuser and a second plane above the first plane, wherein an acute angle is formed between the first plane and the second plane so that the light passing through the prism lens is separated into downward light and upward light; and

an air layer surrounded by the diffuser, the reflector and the prism lens, wherein while an incident angle of the light is increased to a predetermined degree, the light is reflected back to the air layer and is therefore sufficiently mixed.

2. The backlight module according to claim 1, further comprising a bezel including a bottom plane and a side plane, wherein the diffuser is disposed above the bezel, the reflector is disposed on the bottom plane, and the side light source is disposed on the side plane.

3. The backlight module according to claim 1, wherein the reflector is a mirror reflector or a matte finish reflector.

4. The backlight module according to claim 1, further comprising a total internal reflection (TIR) lens, disposed on a bottom of the diffuser and adjacent to the side light source.

5. The backlight module according to claim 4, wherein the total internal reflection (TIR) lens has a reflection surface and a vertical surface, an acute angle is formed by the reflection surface and the diffuser, the vertical surface is perpendicular to the diffuser, and a distance between the vertical surface and the side light source is less than a distance between the reflection surface and the side light source.

6. A backlight module with a bottom plane, comprising:

a diffuser;

a reflector, disposed under the diffuser;

a side light source with a bottom for emitting light, disposed on a side between the diffuser and the reflector;

wherein the reflector extends to a bottom plane of the backlight module from the bottom of the side light source and there is an elevation angle between the reflector and the bottom plane so that the light emitted from the side light source reflected by the reflector travels along a direction nearly parallel to the elevation angle;

a total internal reflection (TIR) lens disposed on a bottom of the diffuser and adjacent to the side light source, wherein the TIR lens has a reflection surface and a vertical surface, an angle is between the reflection surface and the diffuser, the vertical surface is perpendicular to the diffuser, and a distance between the vertical surface and the side light source is less than a distance between the reflection surface and the side light source so that a portion of the light is totally internal reflected and another portion of the light is emitted out of the TIR lens; and

an air layer surrounded by the diffuser, the reflector and the TIR lens, wherein while an incident angle of the light is increased to a predetermined degree, the light is reflected back to the air layer and is therefore sufficiently mixed.

7. The backlight module according to claim 6, further comprising a bezel, wherein the diffuser is disposed above the bezel, the reflector is disposed on a bottom plane of the bezel, and the side light source is disposed on a side plane of the bezel.

8. The backlight module according to claim 6, further comprising a prism lens, disposed between the side light source and the reflector.

9. The backlight module according to claim 8, wherein the prism lens comprises:

a main body; and

a plurality of protruding parts, formed on the main body and facing the side light source, wherein each of the protruding parts has a first plane substantially parallel to the diffuser and a second plane above the first plane, wherein an acute angle is formed between the first plane and the second plane.

10. The backlight module according to claim 6, wherein the reflector is a mirror reflector or a matte finish reflector.