BACKLIGHT UNIT FOR LIQUID CRYSTAL DISPLAY DEVICE

• US 20110001693A1
• Filed: 12/29/2008
• Published: 01/06/2011
• Est. Priority Date: 12/27/2007
• Status: Abandoned Application

• Current Assignee: Samsung Electronics Co. Ltd.
• Original Assignee: Samsung LED Co., Ltd. (Samsung Electronics Co. Ltd.)
• Inventors: Kim, Dae-Yeon, Kim, Hyung-Suk, Kim, Dae-Hyun, Hahn, Hun-Joo
• Application Number:
  US12/810,623
• Publication Number:
  US 20110001693A1
• Time in Patent Office: Days
• US Class Current: 345/102
• CPC Class Codes: G02B 6/0068 Arrangements of plural sources, e.g. multi-colour light sources
• CPC Class Codes: G02B 6/0073 Light emitting diode [LED]
• CPC Class Codes: G02B 6/0078 Side-by-side arrangements, e.g. for large area displays
• CPC Class Codes: G02F 1/133603 with LEDs
• CPC Class Codes: G02F 1/133615 Edge-illuminating devices, i.e. illuminating from the side

Abstract

There is provided a backlight unit for an LCD device. The backlight unit, disposed under a liquid crystal panel and emitting light to a liquid crystal panel, includes a lightguide plate, a light emitting diode (LED) array disposed at an edge of the lightguide plate and including a plurality of LED blocks each including at least one LED emitting white light, and a controller controlling a current signal applied to each of the plurality of LED blocks to regulate the luminance of each LED block. Accordingly, the backlight unit can be provided, which is capable of contributing to manufacturing thinner and larger products and realizing effective local dimming by using an LED disposed at an edge of the lightguide plate.

Claims

1. A backlight unit for a liquid crystal display (LCD) device, disposed under a liquid crystal panel and emitting light to a liquid crystal panel, the backlight unit comprising;

a lightguide plate;

an light emitting diode (LED) array disposed at an edge of the lightguide plate and including a plurality of LED blocks each including at least one LED emitting white light; and

a controller controlling a current signal applied to each of the plurality of LED blocks to regulate the luminance of each LED block.

2. The backlight unit of claim 1, wherein the lightguide plate has at least one separation structure controlling light propagation therein.

3. The backlight unit of claim 2, wherein the separation structure is disposed in at least one of vertical and horizontal directions with respect to the lightguide plate.

4. The backlight unit of claim 2, wherein the separation structure is at least one of an LED array structure and a reflective layer mounted on a circuit board and inserted linearly between the lightguide plates.

5. The backlight unit of claim 2, wherein the separation structure is an uneven part formed at a boundary between regions divided by the separation structure.

6. The backlight unit of claim 1, wherein the LED array comprises a first LED array and a second LED array that are disposed at one edge and the other edge perpendicular to the one edge of the lightguide plate, respectively.

7. The backlight unit of claim 6, wherein light emitted from the first LED overlaps light emitted from the second LED array in the lightguide plate.

8. The backlight unit of claim 6, further comprising a third LED array and a fourth LED array respectively facing the first LED array and the second LED array with the lightguide plate therebetween and having the same configurations as the first and second LED arrays, respectively.

9. The backlight unit of claim 1, wherein the LED array comprises a first LED array and a second LED array disposed at one edge and the other edge facing the one edge of the lightguide plate, respectively.

10. The backlight unit of claim 1, wherein the LED block comprises a red LED, a green LED, and a blue LED.

11. The backlight unit of claim 1, wherein the controller comprises an LED block driving a controller and a panel image signal transmitter.

12. The backlight unit of claim 11, wherein the panel image signal transmitter comprises a panel information transfer circuit and a panel information combination circuit.

13. The backlight unit of claim 1, further comprising a reflective plate disposed under the lightguide plate.

14. The backlight unit of claim 1, further comprising an optical sheet disposed on the lightguide plate.

15. The backlight unit of claim 1, wherein the LED emits white light by at least one fluorescent material.