Backlight unit in liquid crystal display

• US 6,923,548 B2
• Filed: 06/29/2001
• Issued: 08/02/2005
• Est. Priority Date: 12/13/2000
• Status: Expired due to Term

• Current Assignee: LG Display Co., Ltd.
• Original Assignee: LG Philips LCD Company Limited (LG Display Co., Ltd.)
• Inventors: Lim, Moo Jong
• Primary Examiner(s): O'Shea, Sandra
• Assistant Examiner(s): Choi, Jacob Y.
• Application Number:
  US09/893,558
• Publication Number:
  US 20020071288A1
• Time in Patent Office: 1,495 Days
• Field of Search: 362/231, 362/29, 362/31, 362/249, 362/252, 362/800
• US Class Current: 362/612
• CPC Class Codes: G02B 5/02 Diffusing elements; Afocal elements
• CPC Class Codes: G02B 6/0051 Diffusing sheet or layer
• CPC Class Codes: G02B 6/0068 Arrangements of plural sources, e.g. multi-colour light sources
• CPC Class Codes: G02F 1/133621 providing coloured light G02F1/133617, G02F1/133533 take precedence
• CPC Class Codes: G02F 1/133622 Colour sequential illumination
• CPC Class Codes: Y10S 362/80 Light emitting diode

Abstract

A backlight unit in a liquid crystal display enabling to realize high brightness over 2000 nit and provide a thin backlight unit is described. In a backlight unit using LED as a backlight lamp in a field sequence type liquid crystal display including a light-guiding plate, a reflection plate, and a diffusion plate, a plurality of lamps or chips are arranged such that LED chips realizing R, G, and B colors are built in the respective lamps or chips.

Claims

1. A liquid crystal display device, comprising:

a reflection plate;

a diffusion plate having a planar surface; and

a backlight unit using LEDs as a backlight lamp,

wherein a plurality of lamps are arranged such that LED chips realizing R, G, and B colors are built in the respective lamps and wherein the planar surface of the diffusion plate is uniformly and directly exposed to light emitted by the plurality of lamps.

2. The backlight unit in a liquid crystal display of claim 1, wherein each of the lamps has a luminescent area over 100°

.

3. The backlight unit in a liquid crystal display of claim 1, wherein the plurality of lamps are within 10 mm of each other.

4. The backlight unit in a liquid crystal display of claim 1, wherein each of the plurality of LED lamps is within 5 mm of the diffusion plate.

5. The backlight unit in a liquid crystal display of claim 1, further comprising a light-guiding plate.

6. The backlight unit in a liquid crystal display of claim 1, wherein the plurality of lamps are arranged between the reflection plate and the diffusion plate.

7. A liquid crystal display device, comprising:

a reflection plate;

a diffusion plate having a planar surface; and

a backlight unit using LEDs as a backlight lamp,

wherein a plurality of unit chips are arranged such that LED chips realizing R, G, and B colors are built in the respective unit chips and wherein the planar surface of the diffusion plate is uniformly and directly exposed to light emitted by the plurality of unit chips.

8. The backlight unit in a liquid crystal display of claim 7, wherein each of the unit chips has a luminescent area over 100°

.

9. The backlight unit in a liquid crystal display of claim 7, wherein the plurality of unit chips are within 10 mm of each other.

10. The backlight unit in a liquid crystal display of claim 7, wherein each of the plurality of unit chips is within 5 mm of the diffusion plate.

11. The backlight unit in a liquid crystal display of claim 7, further comprising a light-guiding plate.

12. The backlight unit in a liquid crystal display of claim 7, wherein the plurality of unit chips are arranged between the reflection plate and the diffusion plate.

13. A liquid crystal display device, comprising:

a reflection plate;

a diffusion plate having a planar surface; and

a backlight unit using LEDs as a backlight lamp, the backlight unit further comprising;

a plurality of lamps arranged alternatively in a plurality of rows; and

three LED chips built in each of the lamps, the three LED chips realizing R, G, and B colors respectively,

wherein the lamps are turned on/off according to a sequence of a R chip, a G chip, and a B chip in each of the rows and wherein the planar surface of the diffusion plate is uniformly and directly exposed to light emitted by the plurality of lamps.

14. The backlight unit in a liquid crystal display of claim 13, further comprising a light-guiding plate.

15. The backlight unit in a liquid crystal display of claim 13, wherein the plurality of lamps are arranged between the reflection plate and the diffusion plate.

16. A liquid crystal display device, comprising:

a reflection plate;

a diffusion plate having a planar surface; and

a backlight unit using LEDs as a backlight lamp, the backlight unit further comprising;

a plurality of unit chips arranged alternatively in a plurality of rows; and

three LED chips built in each of the unit chips, the three LED chips realizing R, G, and B colors respectively,

wherein the unit chips are turned on/off according to a sequence of a R chip, a G chip, and a B chip in each of the rows and wherein the planar surface of the diffusion plate is uniformly and directly exposed to light emitted by the plurality of unit chips.

17. The backlight unit in a liquid crystal display of claim 16, further comprising a light-guiding plate.

18. The backlight unit in a liquid crystal display of claim 16, wherein the plurality of unit chips are arranged between the reflection plate and the diffusion plate.

19. A liquid crystal display, comprising:

a reflection plate;

a first surface of a backlight lamp on the reflection plate, the backlight lamp including a plurality of lamps arranged in a plurality of rows, each of the plurality of lamps including LED chips realizing R, G, and B colors;

a diffusion plate having a planar surface, wherein the planar surface is on a second surface of the backlight lamp, the first surface opposing the second surface and wherein the planar surface of the diffusion plate is uniformly and directly exposed to light emitted by the plurality of lamps; and

a liquid crystal display panel on the diffusion plate.

20. The liquid crystal display of claim 19, wherein each of the lamps has a luminescent area over 100°

.

21. The liquid crystal display of claim 19, wherein the lamps are within 10 mm of each other.

22. The liquid crystal display of claim 19, wherein the lamps are within 5 mm of the diffusion plate.