Backlight module

• US 8,657,478 B2
• Filed: 03/20/2013
• Issued: 02/25/2014
• Est. Priority Date: 12/06/2006
• Status: Active Grant

• Current Assignee: AU Optronics Corporation
• Original Assignee: AU Optronics Corporation
• Inventors: Liu, Pang-Hsuan
• Primary Examiner(s): Husar, Stephen F
• Application Number:
  US13/847,496
• Publication Number:
  US 20130215641A1
• Time in Patent Office: 342 Days
• Field of Search: 349/65, 362/606, 362/612, 362/613, 362/616, 362/618, 362/620, 362/625, 362/626, 362/628, 385/901
• US Class Current: 362/606
• CPC Class Codes: G02B 6/0018 Redirecting means on the surface of the light guide
• 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 6/0035 provided on the surface of the light guide or in the bulk of it
• CPC Class Codes: G02B 6/0051 Diffusing sheet or layer
• CPC Class Codes: G02B 6/0078 Side-by-side arrangements, e.g. for large area displays

Abstract

A backlight module includes a light guide plate, a light source disposed at a side of the light guide plate, a diffuser sheet positioned over the light guide plate but not directly contacting the light guide plate, and a light mixing space positioned between the light guide plate and the diffuser sheet so that light emitted from the light guide plate mixes in the light mixing space before being emitted out of the backlight module.

Claims

1. A backlight module comprising:

a light guide plate having a light-exit face and at least one light-incidence face, wherein the light-incidence face and the light-exit face of the light guide plate are opposed to each other collaterally;

a light source positioned at a side of the light guide plate, wherein light emitted from the light source enters the light guide plate from the light-incidence face;

a diffuser sheet positioned on the light guide plate without contacting the light guide plate and the light source, the diffuser sheet being parallel to the light-exit face of the light guide plate; and

a light mixing space disposed between the diffuser sheet and the light guide plate wherein the light passing through the light-exit face mixes in the light mixing space before being emitted from the backlight module.

2. The backlight module of claim 1, wherein the light guide plate comprises at least a recessed space to hold the light source.

3. The backlight module of claim 1, further comprising a supporting structure positioned under the light guide plate to hold the light guide plate higher than the light source.

4. The backlight module of claim 3, wherein the supporting structure comprises a reflective element.

5. The backlight module of claim 1, wherein the light guide plate is strip-shaped to make the light passing through the light guide plate become a line-like source.

6. The backlight module of claim 1, wherein the light guide plate comprises a plurality of light guide patterns to guide the light toward the light-exit face, and make light passing through the light-exit face become a plurality of line-like sources.

7. The backlight module of claim 6, wherein the light guide pattern is a V-shaped type or a U-shaped type.

8. The backlight module of claim 1, further comprising a reflective sheet positioned under the light source and the light guide plate.

9. The backlight module of claim 1, further comprising a frame comprising a containing space to hold the light source, the light guide plate and the diffuser sheet, wherein the portion of the containing space surrounded by the light source, the light guide plate and the diffuser sheet forms the light mixing space.

10. The backlight module of claim 1, wherein the light guide plate comprises a reflective face to reflect the light entering the light guide plate laterally and make light passing through the light-exit face become a plurality of line-like sources, and an obtuse angle is between the reflective face and the light-exit face.