Light guide device and backlight module using the same

• US 20060028845A1
• Filed: 08/05/2005
• Published: 02/09/2006
• Est. Priority Date: 08/06/2004
• Status: Active Grant

• Current Assignee: Hon Hai Precision Industry Co., Ltd.
• Original Assignee: Hon Hai Precision Industry Co., Ltd.
• Inventors: Lin, Jhy-Chain
• Granted Patent: US 7,252,426 B2
• Time in Patent Office: Days
• US Class Current: 362/623
• CPC Class Codes: G02B 6/0055 Reflecting element, sheet or layer
• CPC Class Codes: G02B 6/0063 for extracting light out both the major surfaces of the light guide

Abstract

A light guide device (1) and a backlight module (3) using the same. The light guide device includes a light guide plate (11) and a reflective mirror (10). The light guide plate has at least one light receiving surface (111), and two opposite light emitting surfaces (112,113). The reflective mirror is set between the light emitting surfaces, and is integrally manufactured with the light guide plate. The light guide device and backlight module using the same may be applied to optoelectronic devices, such as liquid crystal displays, overhead projectors, etc. The light guide device has a simple structure, and transforms light from at least one light source (31) into two surface light sources emitting light with uniform brightness.

Claims

1. A light guide device, comprising:

a light guide plate including at least one light receiving surface and two opposite light emitting surfaces; and

a light reflective mirror set between the light emitting surfaces.

2. The light guide device according to claim 1, wherein the light guide plate is generally flat, and has a uniform thickness.

3. The light guide device according to claim 1, wherein the light guide plate is curved.

4. The light guide device according to claim 1, wherein the light guide plate is wedge-shaped.

5. The light guide device according to claim 1, wherein the light reflective mirror is set midway between the light emitting surfaces.

6. The light guide device according to claim 1, wherein the light reflective mirror is integrally manufactured with the light guide plate.

7. The light guide device according to claim 1, wherein the light reflective mirror comprises reflective dots on two major surfaces thereof.

8. The light guide device according to claim 7, wherein the light reflective mirror has reflective dots distributed over an entire area of one of the major surfaces thereof, and reflective dots distributed over part of the other major surface thereof.

9. The light guide device according to claim 7, wherein the light reflective dots are hemispherical.

10. The light guide device according to claim 7, wherein the light reflective dots are dome-shaped.

11. The light guide device according to claim 7, wherein the light reflective dots are pyramidal.

12. A backlight module comprising:

a light guide device, including;

a light guide plate having at least one light receiving surface and two opposite light emitting surfaces; and

a light reflective mirror set between the light emitting surfaces of the light guide plate;

at least one light source facing toward the light receiving surface; and

two light diffusers located adjacent opposite sides of the light guide device respectively.

13. The backlight module according to claim 12, wherein said light reflective mirror is manufactured with said light guide plate as one.

14. The backlight module according to claim 12, wherein said light reflective mirror has reflective dots on the two surfaces of said light reflective mirror.

15. The backlight module according to claim 14, wherein said light reflective dots may be semi-sphere.

16. The backlight module according to claim 14, wherein said light reflective dots may be semi-spheroid.

17. The backlight module according to claim 14, wherein said light reflective dots may be diamond.

18. The backlight module according to claim 12, wherein the light source is selected from the group consisting of a light emitting diode and a phosphor lamp.

19. A display device comprising:

a light source providing lights for said display device; and

a light guide device disposed next to said light source to receive said lights from said light source, said light guide device defining two light emitting surfaces thereon to emit said received lights out of said light guide device for further use of said display device, a light reflector disposed in said light guide device, and capable of separating said received lights into two groups of lights and reflecting each group of lights toward one of said two light emitting surfaces respectively.

20. The display device according to claim 19, wherein said light reflector is made of silver and has a plurality of reflective dots formed thereon to face each of said two light emitting surfaces respectively.