Light guide plate, backlight module and liquid crystal display

• US 8,308,337 B2
• Filed: 12/31/2008
• Issued: 11/13/2012
• Est. Priority Date: 09/22/2008
• Status: Active Grant

• Current Assignee: AU Optronics Corporation
• Original Assignee: AU Optronics Corporation
• Inventors: Yeh, Yao-Chung
• Primary Examiner(s): Sawhney, Hargobind S
• Application Number:
  US12/318,547
• Publication Number:
  US 20100073913A1
• Time in Patent Office: 1,413 Days
• Field of Search: 362/326, 362/330, 362/332, 362/333, 362/336, 362/337, 362/600, 362608-626, 349/57, 349/59, 349/61, 349/62, 349/65, 349/69, 349/70
• US Class Current: 362/620
• CPC Class Codes: G02B 6/0036 2-D arrangement of prisms, protrusions, indentations or roughened surfaces
• CPC Class Codes: G02B 6/0038 Linear indentations or grooves, e.g. arc-shaped grooves or meandering grooves, extending over the full length or width of the light guide
• CPC Class Codes: G02F 1/133615 Edge-illuminating devices, i.e. illuminating from the side

Abstract

A light guide plate, a backlight module and a liquid crystal display are provided. The light guide plate has a first surface at least having one first structure and one second structure formed thereon. The first structure and the second structure are adjacent arranged and are mirror reflection with each other. Each of the first structure and the second structure has a first protrusion having a cross section of eccentric triangle.

Claims

1. A light guide plate, having a first surface with a plurality of pairs of structures, each pair including a first structure and a second structure, wherein:

the first structures and the second structures are alternately arranged and the adjacent first and the second structures of each pair are mirror reflection with each other;

each of the first structures includes at least one first protrusion having a cross section of an eccentric triangle; and

each of the second structures includes at least one second protrusion having a cross section of an eccentric triangle.

2. The light guide plate according to claim 1, wherein the eccentric triangle of at least one of the first protrusion and the second protrusion has a top angle of about 80 degree to 140 degree.

3. The light guide plate according to claim 1, wherein the eccentric triangle of at least one of the first protrusion and the second protrusion has two bottom angles with difference of about 2 degree to 30 degree.

4. The light guide plate according to claim 1, further having a second surface opposite to the first surface, wherein the second surface is with a flat, a sand-blasting pattern or a dots pattern.

5. The light guide plate according to claim 1, further having a second surface opposite to the first surface, wherein the second surface is with a plurality of pairs of structures, each pair including another first structure and another second structure, wherein:

the another first structures and the another second structures are alternately arranged and the adjacent another first and the another second structures of each pair are mirror reflection with each other;

each of the another first structures includes an another first protrusion having a cross section of an eccentric triangle; and

each of the another second structures includes an another second protrusion having a cross section of an eccentric triangle.

6. The light guide plate according to claim 5, wherein the first protrusion of the first surface has an extension direction perpendicular to or parallel to that of the another first protrusion of the second surface.

7. The light guide plate according to claim 5, wherein the first surface and the second surface are mirror reflection.

8. The light guide plate according to claim 1, further having a second surface opposite to the first surface, wherein the second surface is with a plurality of V-shaped protrusions.

9. The light guide plate according to claim 1, wherein each of the first structures further includes a first connection flat located between the two adjacent first protrusions of the first structures.

10. The light guide plate according to claim 9, wherein each of the second structures further includes a second connection flat located between the two adjacent second protrusions of the second structures.

11. A backlight module, comprising:

a light guide plate, having a light input surface and a first surface with a plurality of pairs of structures, each pair including a first structure and a second structure, wherein;

the first structures and the second structures are alternately arranged and the adjacent first and the second structures of each pair are mirror reflection with each other;

each of the first structures includes at least one first protrusion having a cross section of an eccentric triangle; and

each of the second structures includes at least one second protrusion having a cross section of an eccentric triangle; and

a light source disposed adjacent to the light input surface.

12. The backlight module according to claim 11, wherein the extension direction of the light source and that of the first protrusion of the first structures form an angle of about 75 degree to 105 degree.

13. The backlight module according to claim 11, wherein the extension direction of the light source and that of the first protrusion of the first structures form an angle of about 90 degree.

14. The backlight module according to claim 11, wherein the light source comprises a plurality of light-emitting diodes (LEDs), cold cathode fluorescent lamp (CCFL) or external electrode fluorescent lamp (EEFL).

15. A liquid crystal display, comprising:

a backlight module, comprising;

a light guide plate, having a light input surface and a first surface with a plurality of pairs of structures, each pair including a first structure and a second structure, wherein;

the first structures and the second structures are alternately arranged and the adjacent first and the second structures of each pair are mirror reflection with each other;

each of the first structures includes at least one first protrusion having a cross section of an eccentric triangle; and

each of the second structures includes at least one second protrusion having a cross section of an eccentric triangle; and

a light source disposed adjacent to the light input surface; and

a liquid crystal display panel disposed above the backlight module.