Light guide plates and backlight module

• US 8,057,056 B2
• Filed: 06/16/2009
• Issued: 11/15/2011
• Est. Priority Date: 08/09/2008
• Status: Active Grant

• Current Assignee: Hon Hai Precision Industry Co., Ltd., Tsinghua University
• Original Assignee: Hon Hai Precision Industry Co., Ltd., Tsinghua University
• Inventors: Zhao, Yan, Jin, Guo-Fan, Zhu, Jun, Zhang, He
• Primary Examiner(s): Sawhney; Hargobind S
• Application Number:
  US12/485,267
• Publication Number:
  US 20100033955A1
• Time in Patent Office: 882 Days
• Field of Search: 362 971- 974, 362/223, 362/327, 362/330, 362/346, 362/348, 362/558, 362/561, 362600- 62, 349/56, 349/57, 349 61- 65, 349 67- 70
• US Class Current: 362/97.1
• CPC Class Codes: G02B 6/0018 Redirecting means on the surface of the light guide
• CPC Class Codes: G02B 6/0036 2-D arrangement of prisms, protrusions, indentations or roughened surfaces
• CPC Class Codes: G02B 6/0061 to provide homogeneous light output intensity
• CPC Class Codes: G02F 1/133603 with LEDs

Abstract

A light guide plate includes a body having a bottom surface and a light output surface opposite to the bottom surface. A scattering structure is formed on the bottom surface. The scattering structure includes a plurality of scattering dots located in the form of a plurality of concentric shapes about the center. A backlight module using the light guide plate is also provided.

Claims

1. A backlight module comprising:

a light guide plate including a bottom surface, a light output surface opposite to the bottom surface;

a light source located adjacent to a center of the bottom surface;

a reflective plate, comprising a portion allowing light to pass through, and located between the light source and the bottom surface; and

at least one scattering structure formed on the bottom surface or the light output surface, and the scattering structure comprises a plurality of scattering dots arranged in the form of a plurality of concentric shapes about the center of the bottom surface or a center of the light output surface.

2. The backlight module as claimed in claim 1, wherein the reflective plate comprises a reflective film located on a surface of the reflective plate.

3. The backlight module as claimed in claim 1, further comprising a brightness enhancement film located above the light output surface of the light guide plate.

4. The backlight module as claimed in claim 1, further comprising a light scattering film located above the light output surface of the light guide plate.

5. The backlight module as claimed in claim 1, further comprising a microprism plate, a polarization plate and a diffusing plate.

6. The light guide plate as claimed in claim 1, wherein the plurality of concentric shapes are round, polygonal or both round and polygonal.

7. The light guide plate as claimed in claim 6, wherein part of the plurality of scattering dots adjacent to the center are arranged in a plurality of concentric circles, and part of the plurality of scattering dots adjacent to edges are arranged in a plurality of concentric polygons.

8. The light guide plate as claimed in claim 7, wherein a ratio of the number of circles to the number of polygons is less than 20:

1.

9. The light guide plate as claimed in claim 7, wherein a second plurality of scattering dots are located in an area between the most outside of concentric circle and the most inside of concentric polygon;

the second plurality of scattering dots are arranged in a circular arcs.

10. The light guide plate as claimed in claim 9, wherein the most outside of concentric circle is tangential to the most inside of concentric polygon.

11. The light guide plate as claimed in claim 7, wherein the plurality of concentric polygons substantially corresponds to a shape of the light guide plate.

12. The light guide plate as claimed in claim 1, wherein two adjacent concentric shapes have a distance between them that ranges from about 0.5 millimeters to about 2 millimeters.

13. The light guide plate as claimed in claim 1, wherein a density of the plurality of scattering dots increases further away from the center.

14. The light guide plate as claimed in claim 1, wherein some of the plurality of scattering dots on the same concentric shape are dispersed uniformly, and a distance between adjacent two scattering dots on the same concentric shape ranges from about 0.1 millimeters to about 1 millimeter.

15. The light guide plate as claimed in claim 1, wherein a density of the plurality of scattering dots on each of the plurality of concentric shapes increases further away from the center.

16. The light guide plate as claimed in claim 1, wherein exposed surfaces of the plurality of scattering dots are coated with reflective material.

17. The light guide plate as claimed in claim 1, wherein both the bottom surface and the light output surface have scattering structure formed thereon.

18. The light guide plate as claimed in claim 1, further comprising a reflector located opposite to the center;

the reflector protrudes from the light output surface to the inside of the light guide plate.

19. A backlight module comprising:

a light guide plate including a bottom surface, a light output surface opposite to the bottom surface;

a light source located adjacent to a center of the bottom surface;

a reflective plate comprising a portion allowing light to pass through, and located between the light source and the bottom surface; and

a scattering structure formed on the bottom surface, wherein the scattering structure comprises a plurality of scattering dots arranged in the form of a plurality of concentric shapes about the center of the bottom surface.

20. A backlight module comprising:

a light guide plate including a bottom surface, a light output surface opposite to the bottom surface;

a light source located adjacent to a center of the bottom surface;

a reflective plate comprising a portion allowing light to pass through, and located between the light source and the bottom surface; and

a scattering structure formed on the light output surface, wherein the scattering structure comprises a plurality of scattering dots arranged in the form of a plurality of concentric shapes about the center of the light output surface.