Surface light source device and liquid crystal display device

Patent metadata

Field	Value
Publication number	US-2016109633-A1
Application number	US-201514861045-A
Country	US
Kind code	A1
Filing date	Sep 22, 2015
Priority date	Oct 20, 2014
Publication date	Apr 21, 2016
Grant date	—

Abstract

A surface light source device includes a first light source for emitting first light, a first light guide rod for causing the first light to be incident thereon and converting the first light into first linear light, a second light source for emitting second light having a greater divergence angle than the first light, and a second light guide rod for converting the second light into second linear light extended in the same direction as the first linear light. Moreover, the surface light source device includes a reflecting bar disposed on an emitting side of the planar light from the first and second light guide rods, and a reflecting portion taking such a box shape as to have an internal wall serving as a reflecting surface, and having an opening portion on a surface at the emitting side of the planar light.

First claim

What is claimed is:

1 . A surface light source device for emitting planar light, comprising:
a first light source for emitting first light; a first light guide rod having an incident surface, causing said first light to be incident from the incident surface and converting said first light into first linear light; a second light source for emitting second light having a greater divergence angle than said first light; a second light guide rod having an incident surface, causing said second light to be incident from the incident surface and converting said second light into second linear light extended in the same direction as said first linear light; a reflecting bar disposed on an emitting side of said planar light from said first light guide rod and said second light guide rod; and a reflecting portion taking such a box shape as to accommodate said first light guide rod, said second light source, said light guide rod and said reflecting bar and to have an internal wall serving as a reflecting surface for reflecting said first linear light and said second linear light, and having an opening portion on a surface at the emitting side of said planar light, wherein said first linear light and said second linear light are reflected by said reflecting bar and said reflecting surface and are emitted from said opening portion to an outside of said reflecting portion.

2 . The surface light source device according to claim 1 , wherein the incident surface of said first light guide rod includes a first incident surface and a second incident surface which are end faces in a longitudinal direction of said first light guide rod, and
a pair of light sources is provided as said first light source in opposed positions to said first incident surface and said second incident surface.

3 . The surface light source device according to claim 2 , wherein said first light guide rod has ends including said first incident surface and said second incident surface protruded to the outside of said reflecting portion,
said first light source is disposed on the outside of said reflecting portion, and said second light source and said second light guide rod are disposed on the inside of said reflecting portion.

4 . The surface light source device according to claim 2 , wherein the incident surface of said second light guide rod is a third incident surface formed on an opposite side to said emitting side in a longitudinal direction of said light guide rod, and
said second light source is disposed in an opposed position to said third incident surface.

5 . The surface light source device according to claim 2 further comprising a lens for collecting said first light,
said lens being disposed either between said first incident surface and said first light source opposed thereto or between said second incident surface and said first light source opposed thereto.

6 . The surface light source device according to claim 4 , wherein said first light guide rod is disposed on said opening portion side from said second light guide rod.

7 . The surface light source device according to claim 1 , wherein said first light guide rod is constituted by using a transparent material and a diffusing material having a higher refractive index than said transparent material, and diffuses, reflects and emits said first light which is incident.

8 . The surface light source device according to claim 1 , wherein said first light source is a laser beam source.

9 . The surface light source device according to claim 1 , wherein said second light source is an LED light source.

10 . A surface light source device for emitting planar light, comprising:
a light source; a light guide rod for receiving light from said light source and converting said light into linear light; a reflecting bar disposed on an emitting side of said planar light from said light guide rod; and a reflecting portion taking such a box shape as to accommodate said light source, said light guide rod and said reflecting bar and to have an internal wall serving as a reflecting surface for reflecting said linear light, and having an opening portion on a surface at the emitting side of said planar light, wherein said linear light is reflected by said reflecting bar and said reflecting surface and is emitted from said opening portion to an outside of said reflecting portion.

11 . A liquid crystal display device comprising:
the surface light source device according to claim 1 , and a liquid crystal panel for displaying an image through illumination with light from said surface light source device.

Assignees

• Mitsubishi Electric Corp

Inventors

• Kida Hiroshi
• Daijogo Akira
• Maeda Saki
• Okimoto Nami
• Niikura Eiji

Classifications

• G02B6/001 Primary

  the light being emitted along at least a portion of the lateral surface of the fibre · CPC title

• G02B6/0006

  Coupling light into the fibre (in general G02B6/4298) · CPC title

• G02B6/0078

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

• G02F1/133624

  characterised by their spectral emissions · CPC title

• G02F1/133615 Primary

  Edge-illuminating devices, i.e. illuminating from the side · CPC title