Backlight unit and liquid crystal display using the same

• US 20060285326A1
• Filed: 06/13/2006
• Published: 12/21/2006
• Est. Priority Date: 06/15/2005
• Status: Active Grant

• Current Assignee: LG Display Co., Ltd.
• Original Assignee: LG Philips LCD Company Limited (LG Display Co., Ltd.)
• Inventors: Jeon, Seong Man
• Granted Patent: US 7,566,146 B2
• Time in Patent Office: Days
• US Class Current: 362/247
• CPC Class Codes: G02F 1/133603 with LEDs
• CPC Class Codes: G02F 1/133605 including specially adapted reflectors

Abstract

A backlight unit includes a case; a first reflector on a surface of the case; a light source disposed on the first reflector; and a second reflector having a first reflective portion and a second reflective portion along first and second sides of the case.

Claims

1. A backlight unit, comprising:

a case;

a first reflector on a surface of the case;

a light source disposed on the first reflector; and

a second reflector having a first reflective portion and a second reflective portion along first and second sides of the case.

2. The backlight unit of claim 1, further comprising a diffusion plate disposed over the light source and the second reflector.

3. The backlight unit of claim 1, wherein each of the first and second reflective portions has a curved surface.

4. The backlight unit of claim 3, wherein the curved surface includes a logarithmic shape.

5. The backlight unit of claim 2, wherein the first reflector and the second reflector mix light emitted from the light source toward the diffusion plate.

6. The backlight unit of claim 1, wherein the second reflector includes third and fourth reflective portions respectively extending from the first and second reflective portions.

7. The backlight unit according to claim 6, wherein the first and second sidewalls are on opposite sides of the case and have a first gradient angle with respect to the first reflector, and the third and fourth portions extend symmetrically from the first and second portions at a second gradient angle with respect to the first reflector.

8. The backlight unit of claim 2, wherein the first gradient angle is larger than the second gradient angle.

9. The backlight unit according to claim 1, wherein the first and second reflective portions are on opposite sides of the case and have a first gradient angle with respect to the first reflector.

10. The backlight unit according to claim 1, wherein the light source includes side emitting type light emitting diodes.

11. The backlight unit according to claim 1, wherein the light source includes a red, a green and a blue light emitting diodes in a row.

12. The backlight unit according to claim 1, wherein the first and second reflective portions are perpendicular to the first reflector and on opposite sides of the case.

13. The backlight unit of claim 12, wherein the second reflector includes third and fourth reflective portions respectively extending from the first and second reflective portions.

14. The backlight unit according to claim 12, wherein the light source includes side emitting type light emitting diodes.

15. The backlight unit according to claim 12, wherein the light source includes a red, a green, and a blue light emitting diodes in a row.

16. The backlight unit according to claim 1, further comprising a third reflector at a middle part of the case.

17. The backlight unit of claim 16, wherein the third reflector includes a double-sided reflector.

18. The backlight unit according to claim 16, wherein the light source includes at least a first row of light emitting diodes on a first side of the third reflector and at least a second row of light emitting diodes on a second side of the third reflector.

19. The backlight unit according to claim 16, wherein a first height of the first and second reflective portions from the first reflector is greater than a second height of the third reflector above the first reflector.

20. A backlight unit, comprising:

a case;

a first reflector on a surface of the case;

at least one row of light emitting diodes disposed on the first reflector; and

a second reflector having a first reflective portion and a second reflective portion along first and second sides of the case, each of the first and second reflective portions extending to a first height above the first reflector, a first distance between the first and second reflective portions is greater than the first height.

21. The backlight unit of claim 20, further comprising a diffusion plate disposed over the at least one row of light emitting diodes and the first reflector.

22. The backlight unit of claim 20, further comprising third and fourth reflective portions respectively extending from the first and second reflective portions.

23. The backlight unit according to claim 20, wherein the at least one row of light emitting diodes includes side emitting type light emitting diodes.

24. The backlight unit according to claim 22, wherein the first and second reflective portions are on opposite sides of the case and have a first gradient angle with respect to the first reflector, and the third and fourth reflective portions extend symmetrically from the first and second reflective portions at a second gradient angle with respect to the first reflector.

25. The backlight unit according to claim 20, wherein the first and second reflective portions are on opposite sides of the case and have a first gradient angle with respect to the first reflector.

26. The backlight unit according to claim 20, wherein the first and second reflective portions are perpendicular to the first reflector.

27. The backlight unit according to claim 26, further comprising a third reflector at a middle part of the case.

28. The backlight unit of claim 27, wherein the third reflector includes a double-sided reflector.

29. The backlight unit according to claim 27, wherein the light source includes at least a first row of light emitting diodes on a first side of the third reflector and at least a second row of light emitting diodes on a second side of the third reflector.

30. The backlight unit according to claim 27, wherein the first height of the first and second reflective portions from the first reflector is greater than a third height of the third reflector above the first reflector.

31. A liquid crystal display device, comprising:

a backlight unit including a case, a first reflector on a surface of the case, a light source disposed on the first reflector, a second reflector having a first reflective portion and a second reflective portion along first and second sides of the case, and a diffusion plate disposed over the light source and the second reflector; and

a liquid crystal display panel disposed over the diffusion plate for displaying a picture using light emitted from the backlight unit.

32. The backlight unit according to claim 31, wherein the first and second sidewalls are on opposite sides of the flat bottom surface and have a first gradient angle, and the third and fourth side walls extend symmetrically from the first and second side walls at a second gradient angle.

33. The backlight unit according to claim 31, wherein the first and second side walls are perpendicular to the flat bottom surface of the reflector plate and on opposite sides of the flat bottom surface, and the third and fourth side walls extend symmetrically from the first and second side walls at a first gradient angle.