LIGHT GUIDE PLATE AND LIQUID CRYSTAL DISPLAY APPARATUS USING THE SAME

• US 20130300979A1
• Filed: 12/05/2012
• Published: 11/14/2013
• Est. Priority Date: 05/10/2012
• Status: Active Grant

• Current Assignee: LG Display Co., Ltd.
• Original Assignee: LG Display Co., Ltd.
• Inventors: Seo, Jeongho, Park, Dongnyuck, Heo, Kang, Park, Hansol
• Granted Patent: US 9,007,546 B2
• Time in Patent Office: Days
• US Class Current: 349/64
• CPC Class Codes: G02B 6/0015 provided on the surface of the light guide or in the bulk of it
• CPC Class Codes: G02B 6/0016 Grooves, prisms, gratings, scattering particles or rough surfaces
• 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

Light can be uniformly distributed in the bezel area by diffusing the light in the bezel area blocked by an upper case, or by providing an optical pattern for light concentration. Accordingly, the brightness of light is similar for all positions at the boundary between the bezel area and the display area, thereby solving the hot spot problem caused by a brightness difference depending on position.

Claims

1. A light guide plate, which allows light emitted from a light source to enter through an incident plane,

the light guide plate comprising:

a pattern unit spaced a predetermined distance away from the incident plane and at least partially disposed in a first direction in parallel with the incident plane,

wherein the light guide plate comprises a bezel area blocked by a bezel and a display area outside the bezel area,

wherein the pattern unit is configured to diffuse light incident through the incident plane in the first direction in the bezel area, and

wherein the bezel area comprises an emission area, which falls within the range of the directivity angle of the light source, and a shaded area, which is out of the range of the directivity angle of the light source, and

wherein a part of the pattern unit is formed in the shaded area.

2. The light guide plate of claim 1,

wherein the pattern unit comprises a compensation pattern which crosses the shaded area so that the ends of the compensation pattern fall within the range of the directivity angle of the light source.

3. The light guide plate of claim 2,

wherein the compensation pattern is spaced away from the incident plane by a distance greater than about 0.3 mm and less than about 0.7 mm.

4. The light guide plate of any one of claim 2 or 3,

wherein the pattern unit further comprises a diffusion pattern which is disposed in both the shaded area and the emission area and is in parallel with the incident plane.

5. The light guide plate of claim 4,

wherein the diffusion pattern is disposed to be more adjacent to the incident plane than the compensation pattern.

6. The light guide plate of claim 5,

wherein the diffusion pattern is spaced away from the incident plane by a distance greater than about 0.8 mm and less than about 1.2 mm, and

wherein the diffusion pattern is spaced away from the compensation pattern by a distance greater than about 0.3 mm and less than about 0.7 mm.

7. The light guide plate of claim 4,

wherein the line width of the compensation pattern and

wherein the diffusion pattern is greater than 8 um and less than 12 um, or greater than about 0.3 mm and less than about 0.7 mm.

8. A liquid crystal display apparatus comprising:

a liquid crystal display panel; and

a backlight unit comprising a light source; and

a light guide plate, which allows light emitted from a light source to enter through an incident plane,

the light guide plate comprising;

a pattern unit spaced a predetermined distance away from the incident plane and at least partially disposed in a first direction in parallel with the incident plane,

wherein the light guide plate comprises a bezel area blocked by a bezel and a display area outside the bezel area,

wherein the pattern unit is configured to diffuse light incident through the incident plane in the first direction in the bezel area, and

wherein the bezel area comprises an emission area, which falls within the range of the directivity angle of the light source, and a shaded area, which is out of the range of the directivity angle of the light source, and

wherein a part of the pattern unit is formed in the shaded area.

9. The liquid crystal display apparatus of claim 8, further comprising:

an upper case and a lower case for packaging the liquid crystal panel and the backlight unit.

10. The liquid crystal display apparatus of claim 8,

wherein the pattern unit comprises a compensation pattern which crosses the shaded area so that the ends of the pattern unit fall within the range of the directivity angle of the light source.

11. The liquid crystal display apparatus of claim 10,

wherein the compensation pattern is spaced away from the incident plane by a distance greater than about 0.3 mm and less than about 0.7 mm.

12. The liquid crystal display apparatus of claim 10,

wherein the pattern unit further comprises a diffusion pattern which is disposed in both the shaded area and the emission area and is in parallel with the incident plane.

13. The liquid crystal display apparatus of claim 11,

wherein the diffusion pattern is disposed to be more adjacent to the incident plane than the compensation pattern.

14. The liquid crystal display apparatus of claim 13,

wherein the diffusion pattern is spaced away from the incident plane by a distance greater than about 0.8 mm and less than about 1.2 mm, and

wherein the diffusion pattern is spaced away from the compensation pattern by a distance greater than about 0.3 mm and less than about 0.7 mm.

15. The liquid crystal display apparatus of claim 12,

wherein the line width of the compensation pattern and the diffusion pattern is greater than about 8 um and less than about 12 um, or greater than about 0.3 mm and less than about 0.7 mm.