Light guide plate, method for producing light guide plate, surface light source device, and liquid crystal display device

Patent metadata

Field	Value
Publication number	US-9551824-B2
Application number	US-201013387863-A
Country	US
Kind code	B2
Filing date	Jul 29, 2010
Priority date	Jul 31, 2009
Publication date	Jan 24, 2017
Grant date	Jan 24, 2017

Abstract

A light guide plate has a light exit surface, a back surface opposed to the light exit surface, and a light entrance surface consisting of at least part of a side surface. The light guide plate also has a body portion, and a light exit-side layer formed from an ionizing radiation curable resin. The light exit-side layer includes an optical element portion which defines the light exit surface. The optical element portion includes unit shaped elements arranged in one direction intersecting a light guide direction, each unit shaped element extending linearly in a direction intersecting the one direction.

First claim

The invention claimed is:

1. A light guide plate comprising:
a light exit surface;
a back surface opposed to the light exit surface;
a light entrance surface consisting of at least part of a side surface between the light exit surface and the back surface;
said light guide plate further comprising:
a body portion; and
a light exit-side layer disposed on a side of the light exit surface side relative to the body portion and formed by curing of an ionizing radiation curable resin;
wherein the light exit-side layer includes an optical element portion which defines the light exit surface and which has a plurality of unit shaped elements arranged in one direction, the one direction intersecting a direction connecting the light entrance surface and a surface which consists of another part of the side surface and which is opposed to the light entrance surface, each unit shaped element extending linearly in a direction intersecting the one direction;
wherein a ratio (L/T) of a length L of the light guide plate, from the light entrance surface to the surface consisting of another part of the side surface and opposed to the light entrance surface, relative to an average thickness T of the light guide plate along a normal direction of a plate plane of the light guide plate, is not more than 500; and
wherein a ratio (t 2 /t 1 ) of an average thickness t 2 of the light exit-side layer along the normal direction of the plate plane of the light guide plate to an average thickness t 1 of the body portion along the normal direction of the plate plane of the light guide plate, is not more than 0.1.

2. The light guide plate according to claim 1 , wherein the unit shaped elements each have a triangular shape in a cross-section along the arrangement direction thereof.

3. The light guide plate according to claim 1 , wherein the light exit-side layer is composed of a single resin material.

4. The light guide plate according to claim 1 , wherein the body portion is composed of a resin and a light scattering component dispersed in the resin.

5. The light guide plate according to claim 1 , wherein the body portion is a plate-like member formed by extrusion molding.

6. A surface light source device comprising:
the light guide plate according to claim 1 ; and
a light source disposed so as to face the light entrance surface of the light guide plate.

7. The surface light source device according to claim 6 , further comprising:
a reflective sheet disposed so as to face the back surface of the light guide plate; and
an optical sheet disposed so as to face the light exit surface of the light guide plate, the optical sheet having unit prisms.

8. A display device comprising:
the surface light source device according to claim 6 ; and
a liquid crystal panel disposed so as to face the surface light source device.

9. The display device according to claim 8 , further comprising a controller configured to control an output of the light source,
wherein the light source includes point-like light emitters arranged so as to face the light entrance surface of the light guide plate; and
wherein the controller adjusts the output of each point-like light emitter according to an image to be displayed.

Assignees

• Yamamoto Hiroshi
• Sekiguchi Hiroshi
• Goto Masahiro
• Kashima Keiji
• Dainippon Printing Co Ltd

Inventors

• Yamamoto Hiroshi
• Sekiguchi Hiroshi
• Goto Masahiro
• Kashima Keiji

Classifications

• G02B6/0065 Primary

  Manufacturing aspects; Material aspects · CPC title

• G02B6/0041

  provided in the bulk of the light guide · CPC title

• Y10T29/49826

  Assembling or joining · CPC title

• G02B6/0038

  Linear indentations or grooves, e.g. arc-shaped grooves or meandering grooves, extending over the full length or width of the light guide · CPC title

• G02F2001/133607

  Physics · mapped topic