Direct type backlight module

• US 20070171626A1
• Filed: 08/23/2006
• Published: 07/26/2007
• Est. Priority Date: 01/21/2006
• Status: Abandoned Application

• Current Assignee: Hon Hai Precision Industry Co., Ltd.
• Original Assignee: Hon Hai Precision Industry Co., Ltd.
• Inventors: Chang, Shao-Han
• Application Number:
  US11/508,635
• Publication Number:
  US 20070171626A1
• Time in Patent Office: Days
• US Class Current: 362/97.300
• CPC Class Codes: G02F 1/133602 Direct backlight
• CPC Class Codes: G02F 1/133605 including specially adapted reflectors
• CPC Class Codes: G02F 1/133628 with cooling means

Abstract

A direct type backlight module includes a diffusion plate, at least a lamp-fixing unit, at least a light source and a reflective plate. The lamp-fixing unit is disposed under one edge of the diffusion plate. The lamp-fixing unit includes an inner surface facing the inner area underneath the diffusion plate, an outer surface opposite to the inner surface, and a plurality of fin structures defined on the outer surface. The light source is fixed on the inner surface of the lamp-fixing unit. The reflective plate is disposed adjacent the lamp-fixing unit and under the diffusion plate, facing the light source. Light rays emitted from the light source being uniformly reflected toward the diffusion plate by the reflective plate. The present backlight module has a thin body and also has a good heat dissipation capability.

Claims

1. A direct type backlight module comprising:

a diffusion plate;

at least a lamp-fixing unit disposed under one edge of the diffusion plate, the lamp-fixing unit having an inner surface facing the inner area underneath the diffusion plate, an outer surface opposite to the inner surface, and a plurality of fin structures defined on the outer surface;

at least a light source fixed on the inner surface of the lamp-fixing unit; and

a reflective plate disposed adjacent the lamp-fixing unit and under the diffusion plate, light rays emitted from the light source being uniformly reflected toward the diffusion plate by the reflective plate.

2. The direct type backlight module according to claim 1, wherein the inner surface of the lamp-fixing unit is slanted with respect to a horizontal portion of a reflective plate.

3. The direct type backlight module according to claim 2, wherein an inclination angle defined by the inner surface of the lamp-fixing unit with respect to the horizontal portion of the reflective plate is chosen to be in a range from about 30 degrees to about 150 degrees.

4. The direct type backlight module according to claim 1, wherein the lamp-fixing unit further comprises an upper reflective portion, the upper reflective portion having a first protruding wall extending from a top of an inner surface of the lamp-fixing unit along a direction parallel to the diffusion plate towards an inner area of the diffusion plate, a second protruding wall extending from a bottom surface of the first protruding wall toward the reflective plate adjacent to the inner surface, the first protruding wall and the second protruding wall cooperatively defining a second reflective surface facing the reflective plate.

5. The direct type backlight module according to claim 1, wherein the lamp-fixing unit further comprises an bottom reflective portion, the bottom reflective unit includes a third protruding wall extending from a bottom of an inner surface of the lamp-fixing unit along a direction parallel to the diffusion plate toward an inner area of the diffusion plate, a fourth protruding wall extending from an upper surface of the third protruding wall toward the diffusion plate adjacent to the inner surface, the third protruding wall and the fourth protruding wall cooperatively defining a third reflective surface facing the diffusion plate.

6. The direct type backlight module according to claim 1, further comprising a first heat conductive layer, sandwiched between the light source and the inner surface of the lamp-fixing unit.

7. The direct type backlight module according to claim 6, further comprising an aluminum based printed circuit board sandwiched between the light source and the first heat conductive layer.

8. The direct type backlight module according to claim 7, further comprising a second heat conductive layer sandwiched between the aluminum base printed circuit board and the light source.

9. The direct type backlight module according to claim 1, further comprising a reflector defining a through hole conformed to the light source therein, the reflector being disposed on the inner surface of lamp-fixing unit, and the light source being exposed through the through hole thereof.

10. The direct type backlight module according to claim 1, further comprising a frame, the frame having a rectangular base according to the diffusion plate, and three sidewalls extending perpendicularly from three edges excluding the edge aligned with the lamp-fixing unit of the base, the diffusion plate being positioned on a top of sidewalls.

11. The direct type backlight module according to claim 1, wherein the backlight module comprises two lamp-fixing units and a plurality of light sources fixed on an inner surface of each lamp-fixing unit, the two lamp-fixing units being disposed under two opposing edges of the diffusion plate respectively.

12. The direct type backlight module according to claim 11, wherein the reflective plate is a curved plate having a crest that has two opposing reflective surfaces, the reflective plate being disposed under the diffusion plate and between the two lamp-fixing units, the two opposing reflective surfaces of the reflective plate facing the two lamp-fixing units respectively.

13. The direct type backlight module according to claim 12, further comprising a frame, the frame having a rectangular base according to the diffusion plate, and only two sidewalls extending perpendicularly from two opposing edges not aligned with the lamp-fixing units of the base, the reflective plate being disposed on the base with the two opposing reflective surfaces facing the light sources and the two lamp-fixing units.

14. The direct type backlight module according to claim 1, wherein a material of the lamp-fixing unit is selected from a group comprising of aluminum, magnesium, copper or their alloys.

15. The direct type backlight module according to claim 1, wherein the light source is selected from a group comprising of light emitting diode and cold cathode fluorescent lamp.

16. A direct type backlight module comprising:

a diffusion plate being a substantially flat sheet having opposite two sides;

a reflective plate disposed at one side of the diffusion plate and spaced from the one side of the diffusion plate; and

a first light source disposed at the one side of diffusion plate and adjacent one edge of the diffusion plate, wherein the reflective plate has at least one reflective portion slanted toward the diffusion plate so that light rays emitted from the first light source is uniformly reflected toward the diffusion plate by the at least one reflective portion.

17. The direct type backlight module of claim 16, wherein the reflective plate is a smooth curved sheet bent towards the diffusion plate.

18. The direct type backlight module of claim 16 further comprising a second light source disposed at the one side of the diffusion plate and adjacent an opposite edge of the diffusion plate with the reflective plate located between the first and second light sources.

19. The direct type backlight module of claim 18, wherein the reflective plate is a curved plate having a crest that has two opposing reflective surfaces, the reflective plate being disposed under the diffusion plate and between the two light sources, the two opposing reflective surfaces of the reflective plate facing the two light sources respectively.

20. The direct type backlight module of claim 16, wherein the first light source comprising an inner surface facing the inner area underneath the diffusion plate, an outer surface opposite to the inner surface, and a plurality of fin structures defined on the outer surface.