Liquid crystal display device using light emitting diode

• US 20040262623A1
• Filed: 06/23/2004
• Published: 12/30/2004
• Est. Priority Date: 06/24/2003
• Status: Active Grant

• Current Assignee: LG Display Co., Ltd.
• Original Assignee: LG Philips LCD Company Limited (LG Display Co., Ltd.)
• Inventors: You, Tae Ho
• Granted Patent: US 7,304,697 B2
• Time in Patent Office: Days
• US Class Current: 257/80
• CPC Class Codes: G02F 1/133603 with LEDs
• CPC Class Codes: G02F 1/133607 the light controlling member including light directing or refracting elements, e.g. prisms or lenses
• CPC Class Codes: G02F 1/133628 with cooling means

Abstract

A liquid crystal display device using a light emitting diode includes a light emitting diode and a radiation plate having an asymmetric shape for making outgoing angle ranges of light exiting from the LED chip different depending on which portion of the asymmetric shaped radiation plate reflected the light.

Claims

1. A liquid crystal display device using a light emitting diode comprising:

a light emitting diode; and

a radiation plate having an asymmetric shape for making outgoing angle ranges of light exiting from the LED chip different depending on which portion of the asymmetric shaped radiation plate reflected the light.

2. The liquid crystal display device using a light emitting diode according to claim 1, further comprising a mold material enclosing the light emitting diode, and a side surface and a rear surface of the radiation plate.

3. The liquid crystal display device using a light emitting diode according to claim 2, further comprising:

a light emitting diode package including the light emitting diode, the radiation plate and the mold material; and

a printed circuit board supporting the light emitting diode package and having a controlling circuit mounted thereon for controlling luminescence of the light emitting diode.

4. The liquid crystal display device using a light emitting diode according to claim 3, further comprising:

a diffusion plate arranged over the printed circuit board;

an optical sheet on the diffusion plate; and

a liquid crystal panel arranged over the optical sheet.

5. The liquid crystal display device using a light emitting diode according to claim 4, wherein a plurality of the printed circuit boards is arranged under the diffusion plate.

6. The liquid crystal display device using a light emitting diode according to claim 3, wherein a plurality of the light emitting diode packages is mounted in parallel with each other on the printed circuit board.

7. The liquid crystal display device using a light emitting diode according to claim 3, wherein the printed circuit board is made of a metal to disperse heat generated from the light emitting diode.

8. The liquid crystal display device using a light emitting diode according to claim 3, wherein the light emitting diode package generates red light, green light and blue light.

9. The liquid crystal display device using a light emitting diode according to claim 3, wherein the light emitting diode package generates white light.

10. The liquid crystal display device using a light emitting diode according to claim 1, wherein an outgoing angle range of light exiting from a long axis portion of the radiation plate has a range within 120°

to 170°

.

11. The liquid crystal display device using a light emitting diode according to claim 1, wherein an outgoing angle range of light exiting from a short axis portion of the radiation plate has a range within 70°

to 130°

.

12. The liquid crystal display device using a light emitting diode according to claim 1, wherein the radiation plate has an oval shape.

13. The liquid crystal display device using a light emitting diode according to claim 1, wherein the light emitting diode includes red, green and blue light emitting diodes.

14. A back light for a liquid crystal display device comprising:

a light emitting diode;

a radiation plate having an oval shape;

a mold material enclosing the light emitting diode, and a side surface and a rear surface of the radiation plate to form a light emitting diode package.

15. The back light according to claim 14, wherein an outgoing angle range of light exiting from a long axis portion of the radiation plate has a range within 120°

to 170°

.

16. The back light according to claim 14, wherein an outgoing angle range of light exiting from a short axis portion of the radiation plate has a range within 70°

to 130°

.

17. A liquid crystal display device comprising:

a printed circuit board;

a plurality of the light emitting diode packages each having an oval-shaped radiation plate, wherein the light emitting packages are mounted in parallel with each other on the printed circuit board;

a diffusion plate positioned over the printed circuit board; and

a liquid crystal panel positioned over the diffusion plate.

18. The liquid crystal display device according to claim 17, wherein an outgoing angle range of light exiting from a long axis portion of the radiation plate has a range within 120°

to 170°

.

19. The liquid crystal display device according to claim 17, wherein an outgoing angle range of light exiting from a short axis portion of the radiation plate has a range within 70°

to 130°

.

20. The liquid crystal display device according to claim 17, wherein the printed circuit board is made of a metal to disperse heat generated from the light emitting diode.