Light guide device and backlight module using the same

• US 7,252,426 B2
• Filed: 08/05/2005
• Issued: 08/07/2007
• Est. Priority Date: 08/06/2004
• Status: Expired due to Fees

• Current Assignee: Hon Hai Precision Industry Co., Ltd.
• Original Assignee: Hon Hai Precision Industry Co., Ltd.
• Inventors: Lin, Jhy-Chain
• Primary Examiner(s): O'Shea; Sandra
• Assistant Examiner(s): Cranson, Jr.; James W
• Application Number:
  US11/198,741
• Publication Number:
  US 20060028845A1
• Time in Patent Office: 732 Days
• Field of Search: 362/616, 362/615
• US Class Current: 362/616
• 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, the light reflective mirror comprising a first interface configured for reflecting a first part of incident light to a first one of the light emitting surfaces, and an opposite second interface configured for reflecting a second part of the incident light to a second one of 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 further comprises reflective dots on the first interface and the second interface thereof.

8. The light guide device according to claim 7, wherein the light reflective mirror has reflective dots distributed over an entire area of the first interface thereof, and reflective dots distributed over part of the second interface 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, comprising;

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

a light reflective mirror integrally set in the light guide plate between the light emitting surfaces of the light guide plate, the light reflective mirror comprising a first interface and an opposite second interface, each interface being wholly in contact with adjacent portions 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 has light reflective dots forming part of said first interface and light reflective dots forming part of said second interface of said light reflective mirror.

14. The backlight module according to claim 13, wherein said light reflective dots are hemispherical.

15. The backlight module according to claim 13, wherein said light reflective dots are semi-spheroid, dome-shaped, conical, or frustum-shaped.

16. The backlight module according to claim 13, wherein said light reflective dots are diamond-shaped or pyramidal.

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

18. A display device comprising:

a light source providing light for said display device; and

a light guide device disposed next to said light source to receive said light from said light source, said light guide device defining two light emitting surfaces thereon to emit said received light out of said light guide device for further use of said display device, a light reflector disposed in said light guide device, said light reflector comprising a first interface, an opposite second interface, reflective dots forming part of said first interface, and reflective dots forming part of said second interface, said light reflector being capable of separating said received light into two groups of light and reflecting each group of light toward one of said two light emitting surfaces respectively.

19. The display device according to claim 18, wherein said light reflector is made of silver.