Backlight unit having optical reflector

• US 7,239,792 B2
• Filed: 12/23/2003
• Issued: 07/03/2007
• Est. Priority Date: 02/18/2003
• Status: Expired due to Fees

• Current Assignee: LG Display Co., Ltd.
• Original Assignee: LG Philips LCD Company Limited (LG Display Co., Ltd.)
• Inventors: Kim, Jae Bum
• Primary Examiner(s): Healy; Brian
• Assistant Examiner(s): PENG, CHARLIE Y
• Application Number:
  US10/742,930
• Publication Number:
  US 20040170373A1
• Time in Patent Office: 1,288 Days
• Field of Search: 385/901, 349 61- 65, 362/545, 362/561, 345/418
• US Class Current: 385/125
• CPC Class Codes: G02B 6/0018 Redirecting means on the surface of the light guide
• CPC Class Codes: G02B 6/0021 for housing at least a part of the light source, e.g. by forming holes or recesses
• CPC Class Codes: G02B 6/0028 Light guide, e.g. taper
• CPC Class Codes: G02B 6/4298 coupling with non-coherent light sources and/or radiation detectors, e.g. lamps, incandescent bulbs, scintillation chambers
• CPC Class Codes: Y10S 385/901 Illuminating or display apparatus

Abstract

A backlight unit is disclosed, in which the light is concentrated when the light is incident on a light-guiding plate so as to improve light efficiency and color realization ratio. The backlight unit includes a light source emitting light; and optical fiber surrounding the circumference of the light source so as to concentrate and emit the light emitted from the light source.

Claims

1. A backlight unit comprising:

a light-guiding plate at the rear of an LCD panel;

first and second light source units at both sides of the light-guiding plate to emit light, each first and second light source unit having at least one luminous element;

a plurality of optical fibers each optical fiber corresponding to the at least one luminous element and surrounding a circumference of the corresponding luminous element of the first and second light source units, to concentrate and to emit the light emitted from the first and second light units; and

a reflecting plate below the light-guiding plate, so as to reflect the light leaking in a direction away from the LCD panel to the light-guiding plate.

2. The backlight unit of claim 1, wherein each optical fiber is one of a glass optical fiber and a plastic optical fiber.

3. The backlight unit of claim 2, wherein the glass optical fiber is any of a silicic optical fiber, a fluoride optical fiber, and a rare-earth optical fiber.

4. The backlight unit of claim 1, wherein the luminous elements include one of a plurality of red, green and blue LEDs, a plurality of white LEDs, and fluorescent lamps.

5. A backlight unit comprising:

a main light-guiding plate at the rear of an LCD panel;

a sub light-guiding plate at one side of the main light-guiding plate;

a light source at one side of the sub light-guiding plate to emit light;

first optical fibers surrounding the circumference of the light source, so as to concentrate and to emit the light emitted from the light source to an incident surface of the sub light-guiding plate;

first and second reflecting plates below the main light-guiding plate, reflecting the light leaking from the main and sub light-guiding plates; and

a second optical fiber surrounding an emitting surface of the sub light-guiding plate and an incident surface of the main light-guiding plate, so as to concentrate and emit the light emitted from the sub light-guiding plate to the incident surface of the main light-guiding plate.

6. The backlight unit of claim 5, wherein the first and second optical fibers are one of a glass optical fiber and a plastic optical fiber.

7. The backlight unit of claim 6, wherein the glass optical fiber is any one of a silicic optical fiber, a fluoride optical fiber, and a rare-earth optical fiber.