# US 2016/0259115 A1 · Prism sheet, surface light source device, image source unit, and liquid crystal display device

> Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt

- Number: US 2016/0259115 A1
- Document ID: US20160259115A1
- Status: Published application
- Kind: A1
- Application number: 15/025,096
- Filed: 2014-09-26
- Published: 2016-09-08
- Earliest claimed: 2013-09-26
- Assignees: Dai Nippon Printing Co., Ltd.
- Applicants: Dai Nippon Printing Co., Ltd.
- Inventors: Keiko KITANO; Daijiro KODAMA
- Web page: https://patentgrep.com/patent/US20160259115A1

## CPC

- G02B 6/0053: {Prismatic sheet or layer; Brightness enhancement element, sheet or layer}
- G02B 5/0231: {the surface having microprismatic or micropyramidal shape (macroscopic prism arrays G02B5/045)}
- G02B 5/0242: {by means of dispersed particles}
- G02B 5/045: {Prism arrays}
- G02B 6/0038: {Linear indentations or grooves, e.g. arc-shaped grooves or meandering grooves, extending over the full length or width of the light guide}
- G02F 1/133308: {Support structures for LCD panels, e.g. frames or bezels}
- G02F 1/133615: {Edge-illuminating devices, i.e. illuminating from the side}
- G02B 6/0041: {provided in the bulk of the light guide}
- G02B: OPTICAL ELEMENTS, SYSTEMS OR APPARATUS
- G02F: OPTICAL DEVICES OR ARRANGEMENTS FOR THE CONTROL OF LIGHT BY MODIFICATION OF THE OPTICAL PROPERTIES OF THE MEDIA OF THE ELEMENTS INVOLVED THEREIN; NON-LINEAR OPTICS; FREQUENCY-CHANGING OF LIGHT; OPTICAL LOGIC ELEMENTS; OPTICAL ANALOGUE/DIGITAL CONVERTERS

## Abstract

Provided is a prism sheet which inhibits the occurrence of scintillations, having less light loss. The prism sheet includes a body portion formed in a sheet, having a light transmitting property, a unit prism portion arranged on one face side of the body portion, having a plurality of unit prisms each having a convex and arrayed in a direction along a sheet face, and a light diffusing layer arranged on the other face side of the body portion, wherein P and Ra have a predetermined relationship wherein P (μm) is a pitch of the plurality of unit prisms and Ra (μm) is a surface roughness of the light diffusing layer.

## Claims

### Claim 1

A prism sheet which changes directions of incident lights to emit the incident lights, the prism sheet comprising:
a body portion formed in a sheet, having a light transmitting property;
a unit prism portion arranged on one face side of the body portion, having a plurality of unit prisms each having a convex shape and arrayed in a direction along a sheet face; and
a light diffusing layer arranged on the other face side of the body portion, wherein:
a vertex angle at a tip of the convex shape of each of the unit prisms is no more than 80°; and
Ra≦−0.0296·P+1.9441 is satisfied wherein P (μm) is a pitch of the plurality of unit prisms, and Ra (μm) is a surface roughness of the light diffusing layer.

### Claim 2

A prism sheet which changes directions of incident lights to emit the incident lights, the prism sheet comprising:
a body portion formed in a sheet, having a light transmitting property;
a unit prism portion arranged on one face side of the body portion, having a plurality of unit prisms each having a convex shape and arrayed in a direction along a sheet face; and
a light diffusing layer arranged on the other face side of the body portion, wherein:
one side across a tip of the convex shape is a light input face of each of the unit prisms, the other side is a reflection face, and the reflection face consists of three faces each having a different inclination angle; and
Ra≦−0.0263·P+2.0537 is satisfied wherein P (μm) is a pitch of the plurality of unit prisms and no less than 10 μm, and Ra (μm) is a surface roughness of the light diffusing layer and no less than 0.035.

### Claim 3

A prism sheet which changes directions of incident lights to emit the incident lights, the prism sheet comprising:
a body portion formed in a sheet, having a light transmitting property;
a unit prism portion arranged on one face side of the body portion, having a plurality of unit prisms each having a convex shape and arrayed in a direction along a sheet face; and
a light diffusing layer arranged on the other face side of the body portion, wherein:
the unit prism is formed in a symmetrical shape and a vertex angle at a tip of the convex shape of each of the unit prisms is no more than 80°; and
Ra≦−0.0208·P+2.0223 is satisfied wherein P (μm) is a pitch of the plurality of unit prisms, and Ra (μm) is a surface roughness of the light diffusing layer.

### Claim 4 (depends on 1)

A surface light source device comprising:
a light source;
a light guide plate which guides lights emitted from the light source; and
the prism sheet according to claim 1, arranged on a light output face side of the light guide plate.

### Claim 5 (depends on 4)

An image source unit comprising:
the surface light source device according to claim 4; and
a liquid crystal panel arranged on a light output side of the surface light source device.

### Claim 6 (depends on 5)

A liquid crystal display device comprising:
the image source unit according to claim 5; and
a housing accommodating the image source unit thereinside.

### Claim 7 (depends on 2)

A surface light source device comprising:
a light source;
a light guide plate which guides lights emitted from the light source; and
the prism sheet according to claim 2, arranged on a light output face side of the light guide plate.

### Claim 8 (depends on 3)

A surface light source device comprising:
a light source;
a light guide plate which guides lights emitted from the light source; and
the prism sheet according to claim 3, arranged on a light output face side of the light guide plate.