Backlight system

• US 20050248695A1
• Filed: 05/02/2005
• Published: 11/10/2005
• Est. Priority Date: 04/30/2004
• Status: Abandoned Application

• Current Assignee: Citizen Electronics Company Limited
• Original Assignee: Citizen Electronics Company Limited
• Inventors: Miyashita, Junji
• Application Number:
  US11/118,763
• Publication Number:
  US 20050248695A1
• Time in Patent Office: Days
• US Class Current: 349/65
• CPC Class Codes: G02F 1/133603 with LEDs
• CPC Class Codes: G02F 1/133615 Edge-illuminating devices, i.e. illuminating from the side

Abstract

A backlight system is provided which comprises a light guide plate formed with a light diffusion surface to reflect light from a light source and a reflection sheet positioned on the light diffusion surface side of the light guide plate. A light scattering area to positively scatter light is formed in the reflection sheet at a position adjacent to the light source to eliminate brightness variations in light rays emitted from the light guide plate, thereby producing a uniform brightness in a planar light emission.

Claims

1. A backlight system comprising:

a light guide plate almost rectangular in plan view, having a light emitting surface on one of its planar surfaces and a light diffusion surface on the other opposite surface to reflect rays of light from a light source;

a light source positioned adjacent to one side of the light guide plate;

a prism sheet positioned on the light emitting surface side of the light guide plate; and

a reflection sheet positioned on the light diffusion surface side of the light guide plate;

wherein a light scattering area to positively scatter light is formed in the reflection sheet at a position adjacent to the light source.

2. A backlight system according to claim 1, wherein the light scattering area formed in the reflection sheet takes the form of a line shape with a width of 3 mm or less extending from one side which is adjacent to the light source side.

3. A backlight system according to claim 1, wherein the light scattering area formed in the reflection sheet is a matte-finished, white light scattering surface.

4. A backlight system according to claim 1, wherein the reflection sheet is formed with a light reflection area next to the light scattering area to reflect light.

5. A backlight system according to claim 4, wherein the light reflection area formed in the reflection sheet is a glossy, metallic mirror surface.