BACK LIGHT UNIT

• US 20040228110A1
• Filed: 02/24/2004
• Published: 11/18/2004
• Est. Priority Date: 05/15/2003
• Status: Active Grant

• Current Assignee: AU Optronics Corporation
• Original Assignee: AU Optronics Corporation
• Inventors: Yu, Chuan-Pei, Liu, Han-Chou, Hsieh, Chin-Kun
• Granted Patent: US 7,101,055 B2
• Time in Patent Office: Days
• US Class Current: 362/31
• CPC Class Codes: F21V 29/51 using condensation or evaporation of a fluid, e.g. heat pipes
• CPC Class Codes: F21V 29/56 using liquid coolants F21V29/51 takes precedence
• CPC Class Codes: F21V 29/74 with fins or blades
• CPC Class Codes: F21V 29/89 Metals
• CPC Class Codes: G02F 1/133602 Direct backlight
• CPC Class Codes: G02F 1/133628 with cooling means
• CPC Class Codes: G09F 13/04 Signs, boards or panels, illuminated from behind the insignia

Abstract

A backlight unit with high thermal dissipation. The back light unit includes a light source generator positioned in a backside of a display panel for providing light beams to the display panel, a diffuser positioned between the light source generator and the display panel for uniformly scattering light beams from the light source generator to the display panel, and a housing enclosing the light source generator and connecting to the diffuser for reflecting the light beams to the diffuser. The housing further includes a heat pipe for being a heat transfer interface between the back light unit and an external environment.

Claims

1. A backlight unit comprising:

a light source generator positioned in a backside of a display panel for providing light beams to the display panel;

a diffuser positioned between the light source generator and the display panel for uniformly scattering light beams from the light source generator to the display panel; and

a housing enclosing the light source generator and connecting to the diffuser for reflecting the light beams to the diffuser, the housing further comprising a heat pipe for being a heat transfer interface between the back light unit and an external environment.

2. The back light unit of claim 1, wherein the heat pipe is composed of metal materials.

3. The back light unit of claim 1, wherein the material of the heat pipe is selected from copper, alumna, tin, or an alloy of any of the above metal materials.

4. The back light unit of claim 1, wherein the heat pipe is a solid heat-conductive pipe.

5. The back light unit of claim 1, wherein the heat pipe is a hollow heat-conductive pipe, and an inner portion of the hollow heat-conductive pipe contains a cooling liquid.

6. The back light unit of claim 1, wherein the heat pipe is connected to the external environment through a radiator piece for transferring heat to the external environment effectively.

7. The back light unit of claim 1, wherein the heat pipe is positioned at a contact point of the diffuser and an up-side of the housing for avoiding affecting paths of the light beams.

8. The back light unit of claim 1, wherein the light source generator comprises a fluorescent tube.

9. The back light unit of claim 8, wherein the heat pipe is positioned directly below the fluorescent tube, and a surface of the heat pipe contains a radiative reflective layer for reflecting light beams from the fluorescent tube.

10. The back light unit of claim 9, wherein the surface of the heat pipe is an arc surface for reducing a rate of light beams emitted from the fluorescent tube being reflected back to the fluorescent tube.

11. The back light unit of claim 1, wherein a contact surface of the heat pipe and the external environment is a rough surface, the rough surface comprising a plurality of sharp teeth so that a radiating area is increased.

12. The back light unit of claim 1 further comprising a diffusion sheet or a prism positioned on the diffuser for increasing the utility of the light resource generator.