LIGHT GUIDE PLATE, METHOD OF MANUFACTURING THE SAME, AND LIQUID CRYSTAL DISPLAY DEVICE INCLUDING THE SAME

• US 20080319715A1
• Filed: 05/01/2008
• Published: 12/25/2008
• Est. Priority Date: 06/22/2007
• Status: Abandoned Application

• Current Assignee: Samsung Electronics Co. Ltd.
• Original Assignee: Samsung Electronics Co. Ltd.
• Inventors: Hwang, In-Sun, Kim, Hyoung-Joo, Shin, Taek-Sun, Kim, Heu-Gon, Yoon, Byung-Seo
• Application Number:
  US12/113,448
• Publication Number:
  US 20080319715A1
• Time in Patent Office: Days
• US Class Current: 703/1
• CPC Class Codes: G02B 6/0025 Diffusing sheet or layer; Prismatic sheet or layer
• CPC Class Codes: G02B 6/0036 2-D arrangement of prisms, protrusions, indentations or roughened surfaces
• CPC Class Codes: 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
• CPC Class Codes: G02B 6/0043 provided on the surface of the light guide
• CPC Class Codes: G02B 6/0061 to provide homogeneous light output intensity
• CPC Class Codes: G02B 6/0068 Arrangements of plural sources, e.g. multi-colour light sources
• CPC Class Codes: G02F 1/133615 Edge-illuminating devices, i.e. illuminating from the side

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

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.

2. The light guide plate of claim 1, wherein an area of the diffuse reflection pattern is reduced as a distance increases from the light incident surface toward the opposite surface.

3. The light guide plate of claim 2, wherein the diffuse reflection pattern has an average roughness decreased as a distance increases from the light incident surface toward the opposite surface.

4. The light guide plate of claim 3, wherein the diffuse reflection pattern is formed in a range of about 80% to about 95% of a length from the light incident surface to the opposite surface.

5. The light guide plate of claim 1, wherein the prism pattern comprises a plurality of intaglio prism lines extending substantially parallel to the light incident surface.

6. The light guide plate of claim 5, wherein a size of the intaglio prism lines gradually increases as a distance increases from the light incident surface toward the opposite surface.

7. The light guide plate of claim 6, wherein the size of at least any one of the intaglio prism lines formed in a region adjacent to the opposite surface decreases as a distance increases from the lateral surfaces to a central region thereof.

8. The light guide plate of claim 5, wherein the light emitting surface further comprises a second prism pattern including a plurality of relief prism lines, in which a groove and a projection are repeatedly formed, and which extend in a direction crossing a direction of extension of the intaglio prism lines.

9. The light guide plate of claim 1, wherein the rear surface further comprises at least one reflection pattern formed in a prism shape between prism lines of the prism pattern to reflect light to the light emitting surface.

10. The light guide plate of claim 9, 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.

11. The light guide plate of claim 10, wherein the reflection pattern is formed in any one of relief and intaglio patterns.

12. The light guide plate of claim 11, wherein the reflection pattern has a vertex angle in a range of about 130°

to about 140°

.

13. The light guide plate of claim 12, wherein the reflection pattern has a height in a range of about 1 μ

m to about 10 μ

m from the rear surface and a width in a range of several tens to several hundreds of micrometers.

14. The light guide plate of claim 13, wherein a number of reflection patterns increases as a distance increases from the light incident surface toward the opposite surface.

15. The light guide plate of claim 13, 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.

16. A liquid crystal display device comprising:

a liquid crystal panel displaying an image;

a light source generating light; and

a light guide plate including a light incident surface to which the light supplied from the light source 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.

17. The liquid crystal display device of claim 16, wherein the diffuse reflection pattern of the light guide plate is formed in a range of about 80% to about 95% of a length from the light incident surface to the opposite surface.

18. The liquid crystal display device of claim 17, wherein the prism pattern is formed with a plurality of intaglio prism lines extending substantially parallel to the light incident surface on the rear surface, and wherein a height of the intaglio prism lines formed in a region adjacent to the opposite surface decreases as a distance increases from the lateral surfaces to a central region thereof.

19. The liquid crystal display device of claim 18, wherein the light guide plate further comprises at least one reflection pattern projected in a prism shape from the rear surface.

20. A method of manufacturing a light guide plate, the method comprising:

forming a light incident surface to which light is incident, an opposite surface formed opposite to the light incident surface, a light emitting surface through which incident light is emitted, a rear surface formed opposite to the light emitting surface, and lateral surfaces;

forming a prism pattern including a plurality of intaglio prism lines on the rear surface; and

forming a diffuse reflection pattern 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.

21. The method of claim 20, where, in forming the diffuse reflection pattern, the diffuse reflection pattern is formed in a range of about 80% to about 95% of a length from the light incident surface to the opposite surface.

22. The method of claim 20, wherein forming the prism pattern including a plurality of intaglio prism lines on the rear surface further comprises forming a reflection pattern in any one of relief and intaglio patterns on the rear surface to reflect light incident between the intaglio prism lines to the light emitting surface.