Backlight unit including a first reflector and a second reflector and liquid crystal display using the same

• US 7,566,146 B2
• Filed: 06/13/2006
• Issued: 07/28/2009
• Est. Priority Date: 06/15/2005
• Status: Expired due to Fees

• Current Assignee: LG Display Co., Ltd.
• Original Assignee: LG Display Co., Ltd.
• Inventors: Jeon, Seong Man
• Primary Examiner(s): CARIASO, ALAN B
• Application Number:
  US11/451,480
• Publication Number:
  US 20060285326A1
• Time in Patent Office: 1,141 Days
• Field of Search: 362/240, 362/241, 362/245, 362/247, 362/97.2, 362/97.3, 362/296.05, 362/296.09, 362/297, 362/304, 362/311.11, 362/349
• 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 having an opening and an inner space;

a reflector installed within the inner space of the case and having a first reflective portion and a second reflective portion; and

a light source disposed on the first reflective portion of the reflector;

wherein the first reflective portion is a flat bottom surface,

wherein the second reflective portion of the reflector is provided along first and second sides of the case, and

wherein the second reflective portion of the reflector includes;

a first side wall and a second side wall on opposite sides of the case having a first gradient angle with respect to the first reflective portion of the reflector, wherein the first and second side walls are perpendicular to the first reflective portion and on opposite sides of the case; and

a third side wall and a fourth side wall respectively extending from the first and second side walls and extending symmetrically from an end of the first and second side walls at a second gradient angle with respect to the first reflective portion of the reflector.

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

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

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

5. The backlight unit of claim 1, wherein each of the first and second side walls has a curved surface.

6. The backlight unit of claim 5, wherein the curved surface includes a logarithmic shape.

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

8. 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.

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

10. 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.

11. The backlight unit according to claim 1, further comprising a double-sided reflector at a middle part of the case.

12. The backlight unit of claim 11, wherein the double-sided reflector includes a third reflector.

13. The backlight unit according to claim 11, wherein the light source includes at least a first row of light emitting diodes on a first side of the double-sided reflector and at least a second row of light emitting diodes on a second side of the double-sided reflector.

14. The backlight unit according to claim 11, wherein a first height of the first and second side walls from the first reflective portion of the reflector is greater than a second height of the double-sided reflector above the first reflective portion of the reflector.

15. A backlight unit, comprising:

a case having an opening and an inner space;

a reflector installed within the inner space of the case and having a first reflective portion and a second reflective portion; and

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

wherein the first reflective portion is a flat bottom surface,

wherein the second reflective portion of the reflector is provided along first and second sides of the case, and

wherein the second reflective portion of the reflector includes;

a first side wall and a second side wall extending to a first height above the first reflective portion of the reflector on opposite sides of the case and having a first gradient angle with respect to the first reflective portion of the reflector, a first distance between the first and second side walls is greater than the first height, wherein the first and second side walls are perpendicular to the first reflective portion; and

a third side wall and a fourth side wall respectively extending from the first and second side wall and extending symmetrically from the first and second reflective portions at a second gradient angle with respect to the first reflective portion of the reflector.

16. The backlight unit of claim 15, further comprising a diffusion plate disposed over the at least one row of light emitting diodes and the first reflective portion of the reflector.

17. The backlight unit according to claim 15, wherein the at least row of light emitting diodes includes side emitting type light emitting diodes.

18. The backlight unit according to claim 15, further comprising a double-sided reflector at a middle part of the case.

19. The backlight unit according to claim 18, wherein the light emitting diodes include at least a first row of light emitting diodes on a first side of the double-sided reflector and at least a second row of light emitting diodes on a second side of the double-sided reflector.

20. The backlight unit according to claim 18, wherein the first height of the first and second side walls from the first reflective portion of the reflector is greater than a third height of the double-sided reflector above the first reflective portion of the reflector.

21. A liquid crystal display device, comprising:

a backlight unit including a case having an opening and an inner space, a reflector installed within the inner space of the case and having a first reflective portion and a second reflective portion, a light source disposed on the first reflective portion, and a diffusion plate disposed over the light source and the reflector; and

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

wherein the first reflective portion is a flat bottom surface,

wherein the second reflective portion of the reflector is provided along first and second sides of the case, and

wherein the second reflective portion of the reflector includes;

a first side wall and a second side wall extending to a first height above the first reflective portion of the reflector on opposite sides of the case and having a first gradient angle with respect to the first reflective portion of the reflector, a first distance between the first and second side walls is greater than the first height, wherein the first and second side walls are perpendicular to the first reflective portion of the reflector and on opposite sides of the first reflective portion; and

a third side wall and a fourth side wall respectively extending from the first and second side wall and extending symmetrically from the first and second reflective portions at a second gradient angle with respect to the first reflective portion of the reflector.