Backlight unit of liquid crystal display device and liquid crystal display device using the same

• US 20060002151A1
• Filed: 06/23/2005
• Published: 01/05/2006
• Est. Priority Date: 06/30/2004
• Status: Active Grant

• Current Assignee: LG Display Co., Ltd.
• Original Assignee: LG Display Co., Ltd.
• Inventors: Park, Hee Jeong
• Granted Patent: US 8,235,571 B2
• Time in Patent Office: Days
• US Class Current: 362/631
• CPC Class Codes: G02F 1/133603 with LEDs

Abstract

A direct-type backlight unit having a plurality of light emitting diodes and a liquid crystal display device having the same are disclosed. The backlight unit includes a printed circuit board (PCB); a plurality of light emitting diodes (LEDs) formed on the PCB for emitting light; and a light diffusion unit included in each of the LEDs for diffusing light.

Claims

1. A backlight unit of a display device, comprising:

a printed circuit board (PCB);

a plurality of light emitting diodes (LEDs) formed on the PCB for emitting light; and

a light diffusion unit included in each of the LEDs for diffusing light.

2. The backlight unit according to claim 1, wherein the light diffusion unit includes a fine pattern formed on a lens surface of each LED and wherein the fine pattern is a mixture of a light diffusion material, a pigment and an adhesive and coated on the lens surface.

3. The backlight unit according to claim 2, wherein a density of the light diffusion material in the fine pattern has an effect on various light transmission characteristics.

4. The backlight unit according to claim 1, wherein the light diffusion unit is a diffusion sheet having a fine pattern.

5. The backlight unit according to claim 1, wherein the light diffusion unit is formed by a metal plate coating.

6. The backlight unit according to claim 4, wherein the diffusion sheet is attached on a lens surface of each LED.

7. The backlight unit according to claim 1, wherein each of the LEDs is a point light source and emits a red light, a green light or a blue light.

8. The backlight unit according to claim 1, wherein the PCB includes a circuit for controlling the LEDs.

9. The backlight unit according to claim 7, wherein the PCB supports the LEDs.

10. A liquid crystal display (LCD) device, comprising:

a liquid crystal panel;

a printed circuit board (PCB); and

a plurality of light emitting diodes (LEDs) on the PCB, each of the LEDs including a light diffusion unit for diffusing light.

11. The LCD device according to claim 10, wherein the light diffusion unit diffuses light emitted from each of the LEDs.

12. The LCD device according to claim 10, wherein each of the LEDs is a point light source and emits a red light, a green light or a blue light.

13. The LCD device according to claim 10, wherein the light diffusion unit includes a fine pattern formed on a surface of a lens of the LED.

14. The LCD device according to claim 10, wherein the light diffusion unit includes a mixture of a light diffusion material, a pigment and an adhesive and the mixture is coated on a lens surface of the LED.

15. A display device, comprising:

a display panel and a backlight unit, the backlight unit including a printed circuit board (PCB), a plurality of light emitting diodes (LED) on the PCB and a lens on each of the LEDs, wherein a diffusion pattern is formed on a surface of the lens.

16. The display device according to claim 15, wherein the diffusion pattern includes a light diffusion material.

17. The display device according to claim 15, wherein the diffusion pattern is on a transparent sheet and is attached on the surface of the lens.

18. The display device according to claim 15, wherein the diffusion pattern is a metal plate coating.

19. The display device according to claim 15, wherein the PCB includes a circuit for controlling the LEDs.

20. The display device according to claim 16, wherein a density of the light diffusion material increases the diffusion efficiency of the diffusion pattern.

21. A method of fabricating a backlight unit for a display device, comprising:

preparing a light emitting diode;

forming a lens having a light diffusion unit on the light emitting diode; and

mounting the light emitting diode on a substrate.

22. The method according to claim 21, wherein forming the lens having a light diffusion unit further includes mixing a light diffusion material with a pigment and an adhesive and coating the mixed light diffusion material on a surface of the lens.

23. The method according to claim 21, wherein forming the lens having a light diffusion unit further includes forming a metal plate coating on a surface of the lens.