Surface light source device and liquid crystal display device

Patent metadata

Field	Value
Publication number	US-9703142-B2
Application number	US-201514823031-A
Country	US
Kind code	B2
Filing date	Aug 11, 2015
Priority date	Aug 20, 2014
Publication date	Jul 11, 2017
Grant date	Jul 11, 2017

Abstract

A surface light source device includes a plurality of LEDs for emitting a plurality of light having different colors, and a light guide body for mixing the colors of the plurality of light and emitting light having colors mixed. The light guide body includes a light incident portion for causing the plurality of light to be individually incident, and a light emitting portion provided beside the light incident portion and changing propagation angles of the plurality of light which is incident from the light incident portion and propagated into the light guide body to mix colors, thereby controlling a quantity of light emission from the light guide body and a light emitting position.

First claim

What is claimed is:

1. A surface light source device comprising:
a plurality of light sources for emitting a plurality of light having different colors; and
a light guide body for mixing the colors of said plurality of light and emitting light having colors mixed,
wherein said light guide body includes,
recessed light incident portions for causing said plurality of light to be individually incident, said plurality of light sources being disposed within respective ones of said plurality of light incident portions, and
at least one light emitting portion provided beside one of said light incident portions and for changing propagation angles of said plurality of light, which is incident from said light incident portion and propagated into said light guide body to mix colors, thereby controlling a quantity of light emission from said light guide body and a light emitting position.

2. A surface light source device comprising:
a plurality of light sources for emitting a plurality of light having different colors; and
a light guide body for mixing the colors of said plurality of light and emitting light having colors mixed,
wherein
said light guide body includes a light incident portion for causing said plurality of light to be individually incident, and a light emitting portion provided beside said light incident portion and for changing propagation angles of said plurality of light, which is incident from said light incident portion and propagated into said light guide body to mix colors, thereby controlling a quantity of light emission from said light guide body and a light emitting position,
said light incident portion is provided on an incident surface side of said light guide body, and
said light emitting portion is provided on said incident surface side of said light guide body and controls a quantity of light emission from an emitting surface on an opposite side to said incident surface and said light emitting position.

3. The surface light source device according to claim 2 , wherein said light emitting portion is formed into a recessed portion having a triangular prism shape with said emitting surface side of said light guide body set to be an apex.

4. The surface light source device according to claim 3 , wherein said light emitting portion includes a triangular prism shape having different angles of sides.

5. The surface light source device according to claim 2 , wherein said light incident portion is formed into a recessed portion having a triangular prism shape with said emitting surface side of said light guide body set to be an apex.

6. The surface light source device according to claim 2 , wherein said light guide body further includes a recessed structure portion being provided in a corresponding position to said light incident portion in said emitting surface and having a curved surface concaved toward said light incident portion side.

7. A liquid crystal display device comprising:
the surface light source device according to claim 1 ; and
a liquid crystal panel for displaying an image by illumination of light from said surface light source device.

Assignees

• Mitsubishi Electric Corp

Inventors

• Maeda Saki
• Okimoto Nami
• Niikura Eiji
• Sawanaka Tomohiko
• Kida Hiroshi

Classifications

• G02B6/0001 Primary

  specially adapted for lighting devices or systems (lighting or signalling on vehicles using light guides B60Q1/00; lighting devices for vehicle dashboards B60Q3/10; lighting devices for vehicle interior using light guides B60Q3/62; lighting devices mounted on the vehicle rear part using light guides F21S43/235; measuring arrangements having light conducting pointers G01D13/265; illumination of liquid crystal displays G02F1/1336; illuminated signs G09F13/00) · CPC title

• G02F1/133609 Primary

  including means for improving the color mixing, e.g. white · CPC title

• G02F1/133603

  with LEDs · CPC title

• G02F1/133607

  the light controlling member including light directing or refracting elements, e.g. prisms or lenses · CPC title

• G02B6/0078

  Side-by-side arrangements, e.g. for large area displays · CPC title