Light source of back light module

• US 7,097,339 B2
• Filed: 04/09/2004
• Issued: 08/29/2006
• Est. Priority Date: 04/22/2003
• Status: Active Grant

• Current Assignee: AU Optronics Corporation
• Original Assignee: AU Optronics Corporation
• Inventors: Li, Shu-Hsien, Chou, Shen-Hong
• Primary Examiner(s): Luebke, Renee
• Assistant Examiner(s): Shallenberger, Julie A.
• Application Number:
  US10/709,057
• Publication Number:
  US 20040213017A1
• Time in Patent Office: 872 Days
• Field of Search: 362/612, 362/611, 362/561, 362/628, 362/609, 362/600
• US Class Current: 362/612
• CPC Class Codes: G02B 6/0041 provided in the bulk of the light guide
• CPC Class Codes: G02B 6/0055 Reflecting element, sheet or layer
• CPC Class Codes: G02B 6/0088 of the light guide or other optical sheets in the package
• CPC Class Codes: G02F 1/133603 with LEDs
• CPC Class Codes: G02F 1/133605 including specially adapted reflectors
• CPC Class Codes: G02F 1/133606 including a specially adapted diffusing, scattering or light controlling members

Abstract

A light source inside a back light module comprising a red light-emitting diode, a green light-emitting diode, a blue light-emitting diode, a diffusion device, some supporting elements and reflectors is provided. The red, green and blue light-emitting diodes mount on a holder. The diffusion device is set up over the holder. The diffusion device comprises a transparent body and a plurality of fine particles distributed within the transparent body. The supporting elements are positioned between the diffusion device and the holder. The reflectors are attached to the surface on each side of the holder and the diffusion device. Red, green and blue lights from various light-emitting diodes are thoroughly mixed inside the diffusion device to form a uniform white light.

Claims

1. A light source inside a back light module, comprising:

a plurality of light-emitting diodes mounted on a holder;

a diffusion device set up over the holder, wherein the diffusion device comprises a transparent body and a plurality of fine particles distributed within the transparent body;

a plurality of supporting elements set up between the diffusion device and the holder; and

reflectors positioned on each side of the holder and the diffusion device.

2. The light source of claim 1 wherein the supporting elements have a light-reflecting property.

3. The light source of claim 1, wherein the fine particles within the diffusion device have different refractivity rates.

4. The light source of claim 1, wherein the fine particles within the diffusion device comprise glass particles.

5. The light source of claim 1, wherein the transparent body of the diffusion device comprises a transparent planar substrate.

6. The light source of claim 1, wherein the holder has a light-reflecting property.

7. The light source of claim 1, wherein the light-emitting diodes comprise at least a red light-emitting diode, at least a green light-emitting diode and at least a blue light-emitting diode.

8. A light source inside a back light module, comprising:

at least a first light-emitting diode having a first optical axis;

at least a second light-emitting diode having a second optical axis;

at least a third light-emitting diode having a third optical axis, wherein the first optical axis, the second optical axis and the third optical axis are not parallel to one another;

a diffusion device set up over the first light-emitting diode, the second light-emitting diode and the third light-emitting diode such that the first optical axis, the second optical axis and the third optical axis all converge towards the diffusion device; and

reflectors attached to the surface of the diffusion device such that uncovered portion of the diffusion device constitute a light-incident surface and a light-emitting surface.

9. The light source of claim 8, wherein the first optical axis, the second optical axis and the third optical axis all direct towards a same location within the diffusion device.

10. The light source of claim 8, wherein the first light-emitting diode, the second light-emitting diode and the third light-emitting diode are all mounted on a holder.

11. The light source of claim 8, wherein the light source further comprises a first lens, a second lens and a third lens such that the first lens is positioned between the first light-emitting diode and the diffusion device, the second lens is positioned between the second light-emitting diode and the diffusion device and the third lens is positioned between the third light-emitting diode and the diffusion device.

12. The light source of claim 11, wherein the first lens, the second lens and the third lens comprise cylindrical spherical lenses.

13. The light source of claim 8, wherein diffusion device furthermore comprises:

a transparent body; and

a plurality of fine particles distributed within the transparent body.

14. The light source of claim 13, wherein the fine particles have different refractivity rates.

15. The light source of claim 13, wherein the fine particles within the diffusion device comprise glass particles.

16. The light source of claim 13, wherein material constituting the transparent body of the diffusion device comprises transparent acrylic material.

17. The light source of claim 8, wherein the first light-emitting diode is selected from a group consisting of at least a red light-emitting diode, at least a green light-emitting diode, at least a blue light-emitting diode and an assembly of them.

18. The Tight source of claim 8, wherein the second light-emitting diode is selected from a group consisting of at least a red light-emitting diode, at least a green light-emitting diode, at least a blue light-emitting diode and an assembly of them.

19. The light source of claim 8, wherein the third light-emitting diode is selected from a group consisting of at least a red light-emitting diode, at least a green light-emitting diode, at least a blue light-emitting diode and an assembly of them.