Light Guide Plate, and Backlight Module and Liquid Crystal Display Incorporating Same

• US 20070217224A1
• Filed: 08/02/2006
• Published: 09/20/2007
• Est. Priority Date: 03/15/2006
• Status: Active Grant

• Current Assignee: AUO Corp.
• Original Assignee: AU Optronics Corporation
• Inventors: Chen, Chih-Kuang, Kao, Ko-Chia
• Granted Patent: US 8,033,709 B2
• Time in Patent Office: Days
• US Class Current: 362/615
• CPC Class Codes: G02B 6/0016 Grooves, prisms, gratings, scattering particles or rough surfaces
• CPC Class Codes: G02B 6/0065 Manufacturing aspects; Material aspects
• CPC Class Codes: G02B 6/0073 Light emitting diode [LED]

Abstract

A light guide plate for a liquid crystal display is disclosed. The light guide plate is adapted for use in a side-light emission type of backlight module. The light guide plate comprises a light incidence face that has at least one surface having at least one annular protrusion or recess, thereby enhancing the capability of light diffusion, uniformity of the light distribution, as well as promoting brightness.

Claims

1. A light guide plate including a light incidence face having at least one annular protrusion or recess, and a light emission face substantially perpendicular to the light incidence face.

2. The light guide plate as claimed in claim 1, wherein the at least one annular protrusion of the light incidence face forms a plurality of convex surfaces.

3. The light guide plate as claimed in claim 2, wherein the light incidence face has a light incidence area completely extending along the light incidence face, and the plurality of the convex surfaces are distributed on the plurality of the light incidence area.

4. The light guide plate as claimed in claim 1, wherein the at least one annular protrusion or recess is substantially elliptic-shaped.

5. The light guide plate as claimed in claim 1, wherein the at least one annular protrusion or recess is substantially circular-shaped.

6. The light guide plate as claimed in claim 3, wherein the plurality of convex surfaces are irregularly distributed on the light incidence area.

7. The light guide plate as claimed in claim 3, wherein the plurality of convex surfaces are regularly distributed on the light incidence area.

8. The light guide plate as claimed in claim 1, wherein the light guide plate is made of Poly (3-hydroxybutyrate-co-3-hydroxyvalerate) (PMMA).

9. A backlight module, for use in a liquid crystal display, comprising:

the light guide plate as claimed in claim 1; and

at least one light source disposed adjacent to the light incidence face.

10. The backlight module as claimed in claim 9, wherein the at least one light source is an LED.

11. The backlight module as claimed in claim 10, wherein the LED is a white LED.

12. The backlight module as claimed in claim 9, wherein the at least one light source is a cold cathode fluorescent lamp.

13. The backlight module as claimed in claim 9, wherein the light guide plate is made of Poly (3-hydroxybutyrate-co-3-hydroxyvalerate) (PMMA).

14. The backlight module as claimed in claim 9, further comprising a reflective sheet disposed under the light guide plate.

15. A display device, comprising:

a display panel; and

the backlight module as claimed in claim 13 disposed under the display panel.

16. The display device as claimed in claim 15, further comprising at least one optical sheet disposed between the display panel and the backlight module.