Light emitting diode backlight unit and liquid crystal display having the same

• US 7,481,566 B2
• Filed: 09/21/2006
• Issued: 01/27/2009
• Est. Priority Date: 03/27/2006
• Status: Expired due to Fees

• Current Assignee: LG Display Co., Ltd.
• Original Assignee: LG Display Co., Ltd.
• Inventors: Han, Jeong Hun
• Primary Examiner(s): Lee; Jong-Suk (James)
• Assistant Examiner(s): MAY, ROBERT J
• Application Number:
  US11/524,816
• Publication Number:
  US 20070223248A1
• Time in Patent Office: 859 Days
• Field of Search: 362/606, 362/612, 362608-610, 362/621, 362/623, 362/625, 362632-634, 362244-245, 362/607, 362/622, 362/342, 362/346, 349 64- 67, 385146-147
• US Class Current: 362/621
• CPC Class Codes: G02B 6/0025 Diffusing sheet or layer; Prismatic sheet or layer
• CPC Class Codes: G02B 6/0028 Light guide, e.g. taper
• CPC Class Codes: G02B 6/0031 Reflecting element, sheet or layer
• CPC Class Codes: G02B 6/0068 Arrangements of plural sources, e.g. multi-colour light sources

Abstract

A backlight unit and a liquid crystal display having the backlight are provided. The backlight unit includes a plurality of light emitting diode (LED) chips, a light guide plate for converting light generated from the LED chips into surface light, and a plurality of optical guide modules corresponding to the respective LED chips and disposed between the LED chips and the light guide plate.

Claims

1. A backlight unit comprising:

a circuit board;

a plurality of light emitting diode (LED) chips on the circuit board;

a light guide plate operative to convert light generated from the LED chips into surface light; and

a plurality of optical guide modules corresponding to the respective LED chips and disposed between the plurality of LED chips and the light guide plate, wherein the plurality of optical guide modules further comprise a light scattering unit and a plurality of plates,

wherein the plurality of plates comprises a plurality of louver plates and the plurality of light scattering elements comprises a plurality of slits,

wherein the plurality of louver plates are symmetrically disposed with reference to the plurality of slits.

2. The backlight unit of claim 1, wherein each of the plurality of LED chips comprises red, green and blue LEDs.

3. The backlight unit of claim 1, wherein each of the plurality of LED chips comprises a white LED.

4. The backlight unit of claim 1, wherein the plurality of LED chips are mounted on a circuit board at determined intervals.

5. The backlight unit of claim 1, wherein the plurality of louver plates are inclined at a determined angle with reference to a centerline of an LED chip of the plurality of LED chips.

6. The backlight unit of claim 1, wherein each of the plurality of louver plates have different lengths from each other.

7. The backlight unit of claim 1, wherein distances between the slits disposed at an area corresponding to the plurality of LED chips are less than those between the plurality of slits disposed at other areas.

8. The backlight unit of claim 1, further comprising a reflective unit formed on the circuit board between the plurality of LED chips.

9. A backlight unit comprising:

a circuit board;

a plurality of light emitting diode (LED) chips on the circuit board;

a light guide plate operative to convert light generated from the LED chips into surface light; and

a plurality of optical guide modules corresponding to the respective LED chips and disposed between the plurality of LED chips and the light guide plate, wherein the plurality of optical guide modules further comprise a plurality of light scattering elements formed on a plate,

wherein the plurality of light scattering elements comprises a plurality of slits and bars,

wherein distances between the slits disposed at an area corresponding to the plurality of LED chips are less than those between the plurality of slits disposed at other areas.

10. The backlight unit of claim 9, wherein each of the plurality of LED chips comprises red, green and blue LEDs.

11. The backlight unit of claim 9, wherein each of the plurality of LED chips comprises a white LED.

12. The backlight unit of claim 9, wherein the plurality of LED chips are mounted on the circuit board at determined intervals.

13. The backlight unit of claim 9, further comprising a reflective unit formed on the circuit board between the plurality of LED chips.

14. A method of displaying in a liquid crystal device, the liquid crystal device comprising a circuit board, a plurality of light emitting diode (LED) chips on the circuit board, a light guide plate operative to convert light generated from the LED chips into surface light, and a plurality of optical guide modules corresponding to the respective LED chips and disposed between the plurality of LED chips and the light guide plate, the method comprising:

arranging a circuit board operative to supply electric power to the plurality of LED chips at a light incident area of the light guide plate;

mounting the plurality of LED chips on the circuit board at determined intervals;

arranging the plurality of optical guide modules to enclose respective LED chips of the plurality of LED chips, wherein the plurality of optical guide modules include a plurality of light scattering elements and a plurality of plates,

wherein the plurality of optical guide modules further comprise a plurality of slits and a plurality of louver plates, the method further comprising;

arranging the plurality of slits in front of the plurality of LED chips; and

symmetrically arranging the plurality of louver plates with reference to the plurality of slits.

15. The method of claim 14, further comprising inclining the plurality of louver plates at a determined angle with reference to a centerline of an LED chip of the plurality of LED chips.