# US 8,540,412 B2 · Light guide plate, method of manufacturing the same, and liquid crystal display device including the same

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- Number: US 8,540,412 B2
- Document ID: US8540412B2
- Status: Granted
- Kind: B2
- Application number: 12/838,560
- Filed: 2010-07-19
- Published: 2010-11-04
- Granted: 2013-09-24
- Earliest claimed: 2007-06-22
- Assignees: Samsung Display Co., Ltd.
- Applicants: Hyoung-Joo Kim; Heu-Gon Kim; In-Sun Hwang; Taek-Sun Shin; Byung-Seo Yoon
- Inventors: Hyoung-Joo Kim; Heu-Gon Kim; In-Sun Hwang; Taek-Sun Shin; Byung-Seo Yoon
- Web page: https://patentgrep.com/patent/US8540412B2

## CPC

- G02F 1/133615: {Edge-illuminating devices, i.e. illuminating from the side}
- G02B 6/0025: {Diffusing sheet or layer; Prismatic sheet or layer}
- G02B 6/0061: {to provide homogeneous light output intensity}
- G02B 6/0036: {2-D arrangement of prisms, protrusions, indentations or roughened surfaces}
- 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}
- G02B 6/0043: {provided on the surface of the light guide}
- G02B 6/0068: {Arrangements of plural sources, e.g. multi-colour light sources}
- 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
- G02B: OPTICAL ELEMENTS, SYSTEMS OR APPARATUS

## Abstract

A light guide plate includes a light incident surface to which light is incident as incident light, an opposite surface formed opposite to the light incident surface, a light emitting surface through which the incident light is emitted, a rear surface formed opposite to the light emitting surface and including a prism pattern which reflects the incident light to the light emitting surface, and lateral surfaces, wherein a diffuse reflection pattern is formed on at least any one of the light emitting surface and the lateral surfaces to diffuse-reflect light incident to the lateral surfaces, thus rendering a brightness at both the opposite surface and the light incident surface substantially uniform.

## Claims

### Claim 1

A light guide plate comprising:
a light incident surface to which light is incident as incident light;
an opposite surface formed opposite to the light incident surface;
a light emitting surface through which the incident light is emitted;
a rear surface formed opposite to the light emitting surface and including a prism pattern to reflect the incident light to the light emitting surface; and
lateral surfaces,
wherein a diffuse reflection pattern is formed on at least any one of the light emitting surface and the lateral surfaces to diffuse-reflect light incident to the lateral surfaces, thus rendering a brightness adjacent both the opposite surface and the light incident surface substantially uniform,
wherein the rear surface further comprises at least one reflection pattern formed in a prism shape spaced apart from and interposed between prism lines defining the prism pattern to reflect light to the light emitting surface,
wherein the reflection pattern has a height from the rear surface different from a height of the prism lines defining the prism pattern from the rear surface.

### Claim 2 (depends on 1)

The light guide plate of claim 1, wherein the reflection pattern is formed within a region of the rear surface occupying about 10% of a length between the lateral surfaces, and the region is disposed adjacent at least one of the lateral surfaces.

### Claim 3 (depends on 2)

The light guide plate of claim 2, wherein the reflection pattern is formed in any one of relief and intaglio patterns.

### Claim 4 (depends on 3)

The light guide plate of claim 3, wherein the reflection pattern has a vertex angle in a range of about 130° to about 140°.

### Claim 5 (depends on 4)

The light guide plate of claim 4, wherein the reflection pattern has a height in a range of about 1 μm to about 10 μm from the rear surface and a width in a range of several tens to several hundreds of micrometers.

### Claim 6 (depends on 5)

The light guide plate of claim 5, wherein a number of reflection patterns increases as a distance increases from the light incident surface toward the opposite surface.

### Claim 7 (depends on 5)

The light guide plate of claim 5, wherein at least any one of the height and the width of the reflection pattern gradually increases as a distance increases from the light incident surface toward the opposite surface.

### Claim 8 (depends on 1)

The light guide plate of claim 1, wherein the reflection pattern is formed as a projection extending from the rear surface and formed spaced apart from and interposed between intaglio prism lines defining the prism pattern.