LIGHT GUIDE BLOCK AND RELATED ILLUMINATION DEVICE AND BACKLIGHT MODULE HAVING THE SAME

• US 20090046468A1
• Filed: 03/14/2008
• Published: 02/19/2009
• Est. Priority Date: 08/14/2007
• Status: Active Grant

• Current Assignee: Foxsemicon Integrated Technology Incorporated
• Original Assignee: Foxsemicon Integrated Technology Incorporated
• Inventors: WEI, AN-CHI, LIN, MEI-JIUN, WANG, MENG-HUA
• Granted Patent: US 7,798,681 B2
• Time in Patent Office: Days
• US Class Current: 362/297
• CPC Class Codes: F21V 7/09 with a combination of different curvatures
• CPC Class Codes: G02B 6/0021 for housing at least a part of the light source, e.g. by forming holes or recesses
• CPC Class Codes: G02B 6/0048 with stepwise taper

Abstract

A backlight module (300) includes a plurality of illumination devices (100). Each of the illumination devices includes a light guide block (120) and a point light source (140) optically coupled with the light guide block. The light guide block includes a light exit surface (121), a bottom surface (123) opposite to the light exit surface, and a tapered portion (122) located between the light exit surface and the bottom surface. The bottom surface has a receiving hole (1232) formed therein. The tapered portion includes an outside surface (1221) and a prism array (1224) formed on the outside surface. The point light source is secured in the receiving hole. The plurality of illumination devices are joined with one another and the light exit surfaces of light guide blocks are substantially coplanar and whereby cooperatively constitute a light output surface of the backlight module.

Claims

1. An illumination device comprising:

a light guide block including a light exit surface, and a bottom surface opposite to the light exit surface, the light guide block tapering from the light exit surface to the bottom surface, the light guide block having a receiving hole formed in the bottom surface, and a peripheral stepped side surface interconnecting the light exit surface and the bottom surface; and

a point light source secured in the receiving hole and facing toward the light guide block.

2. The illumination device of claim 1, wherein the receiving hole is arranged on a geometrical center line of the light guide block.

3. The illumination device of claim 1, wherein the light guide block is multi-pyramid in profile.

4. The illumination device of claim 2, wherein the peripheral stepped surface forms a plurality of continuously connected [ring shaped implies it is circular] prisms which are concentrically arranged around the geometrical center line.

5. The illumination device of claim 3, wherein the light guide block is octagon pyramid shaped in profile, and the peripheral stepped side surface comprises eight side surfaces having the same vertex angles.

6. The illumination device of claim 1, wherein the configuration of the light exit surface is selected from a group consisting of quarter round shaped and multi-polygon shaped.

7. The illumination device of claim 1, wherein the light exit surface of the light guide block is substantially planar.

8. The illumination device of claim 1, wherein a thickness of the light guide block is about no more than 1 centimeter, whilst an area of the light exit surface of the light guide block is about no less than 10 times 10 square centimeters.

9. The illumination device of claim 1, wherein the point light source is a light emitting diode.

10. A light guide block comprising:

a light exit surface;

a bottom surface opposite to the light exit surface with a receiving hole formed therein, the receiving hole being configured for receiving a light source therein; and

a peripheral stepped side surface interconnecting the light exit surface and the bottom surface, the light guide block tapering from the light exit surface to the bottom surface.

11. The light guide block of claim 10, wherein the receiving hole is arranged on a geometrical center line of the light guide block, and the peripheral stepped side surface is arranged around the geometrical center line.

12. The light guide block of claim 10 is multi-pyramid in profile.

13. The light guide block of claim 11, wherein the peripheral stepped side surface forms a plurality of continuously connected prisms which are concentrically arranged around the geometrical center line.

14. The light guide block of claim 10, wherein the light exit surface of the light guide block is substantially planar.

15. The light guide block of claim 10, wherein a thickness of the light guide block approximately no more than 1 centimeter, whilst an area of the light exit surface of the light guide block approximately no less than 10 times 10 square centimeters.

16. A backlight module comprising:

a plurality of illumination devices, each of the illumination devices comprising;

a light guide block including a light exit surface, and a bottom surface opposite to the light exit surface, the light guide block tapering from the light exit surface to the bottom surface, the light guide block having a receiving hole formed in the bottom surface thereof, and a peripheral stepped side surface interconnecting the light exit surface and the bottom surface; and

a point light source secured in the receiving hole and facing toward the light guide block;

wherein the illumination devices are arranged in a manner that the light exit surfaces of the light guide blocks are substantially coplanar and cooperatively constitute a light output surface of the backlight module.

17. The back plate module of claim 16, wherein the light guide blocks are in surface contact with one another.

18. The back plate module of claim 16, wherein the light guide blocks are in line contact with one another.

19. The back plate module of claim 16, wherein the receiving hole is arranged on a geometrical center line of the light guide block.