Backlight device

• US 7,510,314 B2
• Filed: 08/15/2005
• Issued: 03/31/2009
• Est. Priority Date: 08/18/2004
• Status: Expired due to Fees

• Current Assignee: Sony Corporation (Sony Group Corp.)
• Original Assignee: Sony Corporation (Sony Group Corp.)
• Inventors: Oku, Takashi, Arai, Takeo
• Primary Examiner(s): Ward; John A
• Application Number:
  US10/595,355
• Publication Number:
  US 20070121320A1
• Time in Patent Office: 1,324 Days
• Field of Search: 362/609, 362/612, 362623-625, 362/800, 362/633, 362/634
• US Class Current: 362/609
• CPC Class Codes: G02F 1/133603 with LEDs

Abstract

The present invention is directed to a backlight device using light emitting units (7) in which a large number of light emitting diodes (12) are mounted, which comprises a reflection plate (16) for reflecting rays of light which have been emitted from a light emitting unit (11), wherein the reflection plate (16) is composed of a bottom surface reflection plate (16a) for reflecting rays of light emitted from the light emitting units (7) from the bottom surface direction, side surface reflection plates (16b) to (16e) for reflecting rays of light emitted from the light emitting units (7) from respective forward and backward, and left and right side surface directions, and corner reflection plates (16f) to (16i) in which the bottom surface reflection plate (16a) and the side surface reflection plates (16b) to (16e) are connected to cover the respective corner portions, and serves to permit rays of light incident onto a display panel (1) to be uniform to realize uniformity of brightness of the entire surface thereof.

Claims

1. A backlight device comprising:

a rectangular surface reflection sheet having front, backward, left side and right side directions along its surface and four corner portions;

a plurality of side reflection sheets;

a plurality of corner reflection sheets;

a light source unit, mounted on the surface reflection sheet, comprising a plurality of light emitting diodes;

a diverter plate located above the light source unit; and

a diffusion sheet located above the diverter plate,

wherein,

the diverter plate reflects light rays orthogonal to its surface back to the rectangular surface reflection sheet,

the diffusion plate reflects light received from the diverter plate to the side and corner reflection sheets,

the side reflection sheets are positioned along respective edges of said rectangular surface reflection sheet and extend at an angle therefrom, adjacent side reflection sheets abutting along adjoining edges,

the corner reflection sheets covering interior corners formed by the surface reflection sheet and the side reflection sheets at the corner portions of the surface reflection sheet,

the side and corner reflection sheets reflect light emitted from the light source unit towards the front, backward, left side and right side surface directions,

light emitting diodes of the light source unit are located at the corner portions of the surface reflection sheet, and

each of the light emitting diodes located in the corner portions of the rectangular surface reflection sheet is equidistant from the two closest side reflection sheets and the corner reflection sheet forming the interior corner at said reflection surface corner portion.

2. The backlight device as set forth in claim 1, wherein a reflection surface of the corner reflection sheet takes a polygonal shape.

3. The backlight device as set forth in claim 1, wherein a reflection surface of the corner reflection sheet takes a flat sheet shape.

4. The backlight device as set forth in claim 1, wherein a reflection surface of the corner reflection sheet takes a spherical shape.