Liquid crystal display device

• US 7,708,450 B2
• Filed: 11/03/2005
• Issued: 05/04/2010
• Est. Priority Date: 11/08/2004
• Status: Expired due to Fees

• Current Assignee: NLT Technologies, Ltd.
• Original Assignee: NEC LCD Technologies Limited (NEC Corporation)
• Inventors: Mikami, Kazuaki
• Primary Examiner(s): Lee; Jong-Suk (James)
• Assistant Examiner(s): Crowe; David R
• Application Number:
  US11/265,089
• Publication Number:
  US 20060098458A1
• Time in Patent Office: 1,643 Days
• Field of Search: 362/561, 362/231, 362/27, 362/555, 362/606, 362/237, 362/240, 362/247, 362/248, 362/300, 362/307, 362/310, 362/347, 362/390, 362/560, 362/581, 362/29, 362/609, 362/31, 362/279, 362/241, 362/267, 362/369, 362/634, 362/97.3, 362/306, 349/63, 349/65, 349/67, 349/62, 349/60
• US Class Current: 362/632
• CPC Class Codes: G02B 6/0018 Redirecting means on the surface of the light guide
• CPC Class Codes: G02B 6/0031 Reflecting element, sheet or layer
• CPC Class Codes: G02F 1/133615 Edge-illuminating devices, i.e. illuminating from the side

Abstract

A liquid crystal display device includes an LED backlighting unit and a liquid crystal display panel disposed on the backlighting unit. The backlighting unit includes a light source of an array of LEDs and a reflector disposed so as to cover the light source and configured to reflect light emitted from the light source. And a light shielding spacer member is provided between the reflector and the LED light source.

Claims

1. A liquid crystal display device, comprising:

a liquid crystal display panel;

a backlighting unit disposed behind the liquid crystal display panel, the backlighting unit including a light source and a reflector disposed to cover the light source from the liquid crystal display panel and configured to reflect substantially all light emitted from the light source to the liquid crystal display panel; and

a light shielding spacer member attached directly to an entire lower surface of the reflector to prevent contact between the reflector and the light source,

wherein an air gap is provided between an opening of the reflector, into which said light source is placed, and said light source, and

wherein said light shielding spacer member extends other than into the opening of the reflector.

2. The liquid crystal display device according to claim 1, wherein the light shielding spacer member has a plate shape.

3. The liquid crystal display device according to claim 1, wherein the light shielding spacer member has a box shape and is disposed to allow a light emitting portion of the light source out of an aperture provided at a bottom of the box shape and to cover the light source.

4. The liquid crystal display device according to claim 1, wherein the light shielding spacer member comprises an elastic resin material.

5. The liquid crystal display device according to claim 1, wherein the backlighting unit further comprises an optical waveguide that guides the light emitted from the light source, which is entirely reflected by the reflector, before entering the optical waveguide.

6. The liquid crystal display device according to claim 5, further comprising:

an optical sheet disposed on the optical waveguide of the backlighting unit.

7. The liquid crystal display device according to claim 1, wherein said light shielding spacer member shields all light transmission other than from said light source to said reflector.

8. A liquid crystal display device, comprising:

a liquid crystal display panel; and

a backlighting unit disposed behind the liquid crystal display panel, the backlighting unit including a light source, a first reflector, a first optical waveguide, a second reflector, a second optical waveguide, and a light shielding spacer member such that the first reflector is disposed to cover the light source and to reflect an entirety of light emitted from the light source to the first optical waveguide,

wherein the first optical waveguide is arranged to allow the light reflected by the first reflector to be incident on an incident surface, and guiding the light toward an emitting surface,

wherein the second reflector is arranged to reflect the light emitted from the first optical waveguide,

wherein the second optical waveguide is disposed above the first optical waveguide to allow the light reflected by the second reflector to be incident, and to guide the light toward an entire surface,

wherein the light shielding spacer member is attached directly to an entire lower surface of the first reflector to prevent contact between the first reflector and the light source and provides elastic cushioning between said reflector and said light source,

wherein an air gap is provided between an opening of the first reflector, into which said light source is placed, and said light source, and

wherein said light shielding spacer member extends other than into the opening of the first reflector.

9. The liquid crystal display device according to claim 8, further comprising:

reflective means located on a back surface of the second optical waveguide in a space between the first optical waveguide and the second optical waveguide that reflects the light emitted from the back surface of the second optical waveguide and that allows the light to be incident on the second optical waveguide.

10. The liquid crystal display device according to claim 8, further comprising:

an optical sheet disposed on the second optical waveguide of the backlighting unit.

11. The liquid crystal display device according to claim 8, wherein the light shielding spacer member includes a plate shape.

12. The liquid crystal display device according to claim 8, wherein the light shielding spacer member includes a box shape with an aperture provided at a bottom of the box shape and is disposed to allow a light emitting portion of the light source out of the aperture and to cover the light source.

13. The liquid crystal display device according to claim 8, wherein the light source comprises a plurality of light emitting diodes mounted on an insulating substrate and configured respectively to emit red light, blue light, and green light.

14. The liquid crystal display device according to claim 8, wherein each of the first reflector and the second reflector comprises a composite material formed by attaching transparent resin on which silver is evaporated to a metal plate selected from the group of aluminum, stainless steel, and brass.

15. The liquid crystal display device according to claim 8, wherein each of the first reflector and the second reflector comprises a composite material formed by attaching white resin to a metal plate selected from a group of aluminum, stainless steel, and brass.

16. The liquid crystal display device according to claim 8, wherein the light shielding spacer member comprises an elastic resin material.

17. The liquid crystal display device according to claim 16, wherein the elastic resin material is colored white.

18. The liquid crystal display device according to claim 16, wherein the elastic resin material is selected from a group of epoxy resin, polyurethane resin, and silicon resin.

19. An illuminated reflector device for a liquid crystal display, said device comprising:

a light source including a plurality of light emitting diodes (LEDs) for illuminating the liquid crystal display;

a reflector disposed to cover said light source and configured to reflect light emitted from said light source; and

a light shielding spacer member attached directly to an entire lower surface of the reflector to prevent contact between said reflector and each of said plurality of LEDS by providing elastic cushioning between said reflector and each of said plurality of LEDs,

wherein said light shielding spacer member prevents damage to said light source from force transmitted by said reflector,

wherein a diameter of an aperture of the light shielding spacer member is set to be larger than an outside diameter of the light source and smaller than a diameter of an aperture of the reflector,

wherein an air gap is provided between the aperture of the reflector, into which said light source is placed, and said light source, and

wherein said light shielding spacer member extends other than into the aperture of the reflector.

20. The liquid crystal display device according to claim 19, wherein the illuminated reflector device further comprises an optical waveguide that guides the light emitted from the light source, which is entirely reflected by the reflector, before entering the optical waveguide.