Backlight unit and display apparatus thereof

Patent metadata

Field	Value
Publication number	US-9053650-B2
Application number	US-201213678133-A
Country	US
Kind code	B2
Filing date	Nov 15, 2012
Priority date	Nov 16, 2011
Publication date	Jun 9, 2015
Grant date	Jun 9, 2015

Abstract

A backlight unit and a display device having the same are provided. The backlight unit includes a light source, a reflector arranged on and under the light source to totally reflect at least a part of light emitted from the light source in a lateral direction, a reflective sheet arranged under the reflector, and a diffusion sheet arranged on the reflector.

First claim

What is claimed is:

1. A backlight unit comprising:
a light source;
a reflector disposed to enclose the light source;
a reflective sheet arranged under the reflector; and
a diffusion sheet arranged over the reflector,
wherein a center axis of the reflector is spaced apart from an optical axis of the light source at a certain distance.

2. The backlight unit according to claim 1 , wherein the reflector has at least one of cross sections shaped like an ellipse and a parabola, and has a reflective layer formed on an inner side thereof.

3. The backlight unit according to claim 1 , wherein the reflector has an opening facing a light emitting surface of the light source.

4. The backlight unit according to claim 1 , wherein the reflector comprises an upper reflector and a lower reflector having different cross section shapes.

5. The backlight unit according to claim 4 , wherein the cross section of the upper reflector is shaped like an ellipse and the cross section of the lower reflector is shaped like a parabola.

6. The backlight unit according to claim 1 , wherein an open angle of the reflector is about 30 degrees or less.

7. The backlight unit according to claim 6 , wherein the reflector comprises an upper reflector and a lower reflector having different open angles.

8. The backlight unit according to claim 7 , wherein the open angle of the upper reflector is smaller than that of the lower reflector.

9. The backlight unit according to claim 1 , wherein the reflective sheet comprises a part where a distance between the reflective sheet and the diffusion sheet decreases as a distance to the light source increases.

10. The backlight unit according to claim 1 , wherein the reflective sheet comprises a first reflective layer and a second reflective layer having different reflectance.

11. The backlight unit according to claim 1 , further comprising a light shielding layer arranged between the reflector and the diffusion sheet, wherein a part of the light shielding layer overlaps the reflector.

12. The backlight unit according to claim 1 , further comprising a substrate on which the light is mounted, wherein the substrate contacts the reflector.

13. The backlight unit according to claim 1 , further comprising another reflector so that an opening thereof faces the opening of the reflector, wherein the two reflectors are respectively arranged on both ends of the backlight unit.

14. The backlight unit according to claim 1 , further comprising another reflector so that an opening thereof and the opening of the reflector face opposite directions, wherein the two reflectors are arranged on a center part of the backlight unit.

15. A display device comprising:
a backlight unit; and
a display panel arranged over the backlight unit,
wherein the backlight unit comprises:
a plurality of light sources;
a reflector disposed to enclose the light sources;
a reflective sheet arranged under the reflector; and
a diffusion sheet arranged over the reflector,

wherein a center axis of the reflector is spaced apart from an optical axis of the light sources at a certain distance.

16. The display device according to claim 15 , wherein the reflector comprises an upper reflector and a lower reflector having different cross section shapes or open angles.

17. The display device according to claim 16 , wherein the cross section of the upper reflector is shaped like an ellipse and the cross section of the lower reflector is shaped like a parabola.

18. The display device according to claim 16 , wherein the open angle of the upper reflector is smaller than that of the lower reflector.

Assignees

• Lg Electronics Inc

Inventors

• Kwon Soonhyung
• Kim Sungwoo
• Han Jongho

Classifications

• G09F13/14 Primary

  Arrangements of reflectors therein · CPC title

• F21V7/06

  with parabolic curvature · CPC title

• F21V7/0008

  providing for indirect lighting · 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

• G02F1/133615 Primary

  Edge-illuminating devices, i.e. illuminating from the side · CPC title