Backlight module

• US 20070171676A1
• Filed: 08/23/2006
• Published: 07/26/2007
• Est. Priority Date: 01/20/2006
• Status: Abandoned Application

• Current Assignee: Hon Hai Precision Industry Co., Ltd.
• Original Assignee: Hon Hai Precision Industry Co., Ltd.
• Inventors: Chang, Shao-Han
• Application Number:
  US11/508,542
• Publication Number:
  US 20070171676A1
• Time in Patent Office: Days
• US Class Current: 362/613
• 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 6/0068 Arrangements of plural sources, e.g. multi-colour light sources
• CPC Class Codes: G02F 1/133603 with LEDs
• CPC Class Codes: G02F 1/133605 including specially adapted reflectors
• CPC Class Codes: G02F 1/133615 Edge-illuminating devices, i.e. illuminating from the side

Abstract

A backlight module includes a housing, at least two light sources, and a light diffusion plate. The housing includes a base, a plurality of sidewalls extending from the peripheral of the base to define an opening, and a protrusion extending out from the base toward the opening. The protrusion defines two opposing reflective surfaces facing two opposing sidewalls respectively. The light diffusion plate is disposed on the opening of the housing. The two light sources are fixed on inner surface of the two opposing sidewalls respectively, the two reflecting surfaces uniformly reflecting light from the light sources toward the light diffusion plate. The present backlight module has a good optical performance, lightweight and thin body.

Claims

1. A backlight module comprising:

a housing having a base, a plurality of sidewalls extending from the peripheral of the base to define an opening, and a protrusion extending out from the base toward the opening, the protrusion having two opposing reflective surfaces facing two opposing sidewalls respectively;

a light diffusion plate disposed on the opening of the housing; and

at least two light sources fixed on inner surfaces of the two opposing sidewalls correspondingly, the two reflecting surfaces uniformly reflecting light from the light sources toward the light diffusion plate.

2. The backlight module according to claim 1, wherein a shape of the protrusion is an elongated ridge extending along a direction parallel to the two opposing sidewalls where the light sources are fixed.

3. The backlight module according to claim 2, wherein the protrusion has a similar semi-circular cross-section taken along a direction perpendicular to the two opposing sidewalls that fixes the light sources thereon, and the two opposing reflective surfaces of the protrusion are curved surfaces connecting with the base.

4. The backlight module according to claim 2, wherein the protrusion has a triangular cross-section taken along a direction perpendicular to two opposing sidewalls that fixes the light sources thereon.

5. The backlight module according to claim 2, wherein protrusion has a stepped-shaped cross-section taken along a direction perpendicular to two opposing sidewalls that fixes the light sources thereon.

6. The backlight module according to claim 1, wherein the housing further comprises two upper reflective units each positioned on a top of the two opposing sidewalls where the light sources are fixed.

7. The backlight module according to claim 6, wherein each upper reflective unit comprises a first protruding portion extending from a top the sidewalls towards an inner area of an upper part of the housing, a second protruding portion extending from a bottom surface of the protruding portion towards the base, and a third reflective surface defined by the intersection between the first protruding portion and the second protruding portion facing the corresponding reflective surface.

8. The backlight module according to claim 6, wherein each upper reflective unit includes a first protruding portion extending from a top of sidewalls towards an inner area of housing, a third reflective surface defined by intersection of the first protruding portion and an inner surface of the corresponding sidewall.

9. The backlight module according to claim 1, wherein the housing further comprises two bottom reflective units each positioned on the base adjacent to the corresponding sidewalls.

10. The backlight module according to claim 9, wherein each bottom reflective unit includes a third protruding portion extending from the base toward the light diffusion plate, and a fourth reflective surface defined by intersection between the base and the third protruding portion, facing the third curved reflective surface and interconnecting the adjacent reflective surface of the protrusion.

11. The backlight module according to claim 9, wherein each bottom reflective unit defines a fourth reflective surface defined by intersection between the base and the corresponding sidewalls and interconnecting the adjacent reflective surface of the protrusion.

12. The backlight module according to claim 1, wherein inner surfaces of two opposing sidewalls that fixes light sources thereon are slanted inwards in respect to the base.

13. The backlight module according to claim 12, wherein an inclination angle defined by the inner surface of the sidewall with respect to the base is configured to be in a range from about 45 degrees to about 90 degrees.

14. The backlight module according to claim 1, wherein the light sources are selected from light emitting diodes and cold cathode fluorescent lamps.

15. The backlight module according to claim 14, wherein the light sources are light emitting diodes, and the light emitting diodes are adhered to the inner surfaces of the two opposing sidewalls.

16. The backlight module according to claim 14, wherein the light sources are light emitting diodes, and the light emitting diodes are aligned apart on an electric circuit board, each electric circuit board with the light emitting diodes is fixed to the inner surface of the two opposing sidewalls.

17. The backlight module according to claim 1, further comprising a prism sheet and a reflective polarizer stacked on the light diffusion plate in that order, for increasing optical brightness.

18. The backlight module according to claim 1, further comprising a highly reflective film deposited on the two reflective surfaces of the protrusion.

19. A backlight module comprising:

a housing including a base and a pair of opposed sidewalls extending from opposite ends the base, the base at a substantially central portion thereof forming a protrusion with a pair of reflective surfaces formed at opposite sides of the protrusion, each of the reflective surfaces substantially rising from a corresponding one of the sidewalls toward the protrusion;

a pair of light sources each fixed to or adjacent a corresponding one of the sidewalls; and

a light diffusion plate placed on the housing with opposite edge portions of the light diffusion plate each aligned with a corresponding one of the sidewalls so that light rays emitted from the light sources are reflected toward the light diffusion plate by the reflective surface.