Backlight unit having heat dissipating layer, display device having heat dissipating layer, and method for manufacturing heat dissipating layer

• US 7,527,408 B2
• Filed: 08/21/2006
• Issued: 05/05/2009
• Est. Priority Date: 10/24/2005
• Status: Expired due to Fees

• Current Assignee: LG Electronics, Inc. (LG Corporation)
• Original Assignee: LG Electronics, Inc. (LG Corporation)
• Inventors: Hwang, Kab Jin
• Primary Examiner(s): O'Shea; Sandra L.
• Assistant Examiner(s): Dunwiddie; Meghan K.
• Application Number:
  US11/506,852
• Publication Number:
  US 20070091588A1
• Time in Patent Office: 988 Days
• Field of Search: 362/294, 362/373, 362/612, 362/614, 362/615, 362/617
• US Class Current: 362/609
• CPC Class Codes: C08K 3/04 Carbon
• CPC Class Codes: G02B 6/0055 Reflecting element, sheet or layer
• CPC Class Codes: G02B 6/0085 Means for removing heat created by the light source from the package heat extraction or cooling elements for semiconductor light sources in general H01L33/64
• CPC Class Codes: G02F 1/133615 Edge-illuminating devices, i.e. illuminating from the side
• CPC Class Codes: G02F 1/133628 with cooling means

Abstract

A backlight unit and a display device having heat dissipating layer, and a method for manufacturing the heat dissipating layer are provided. A backlight unit includes a light source for emitting a light; a reflector below the light source for reflecting the light emitted from the light source and absorbing heat generated by the light source; and a heat dissipating layer including thermal conductive particles, the heat dissipating layer being disposed on a first surface of the reflector for dissipating the heat transferred to the reflector.

Claims

1. A backlight unit, comprising:

a light source for emitting a light;

a reflector below the light source for reflecting the light emitted from the light source and absorbing heat generated by the light source;

a heat dissipating layer including thermal conductive particles, the heat dissipating layer being disposed on and in direct contact with a first surface of the reflector for dissipating the heat transferred to the reflector;

a light guide plate for guiding the light emitted from the light source, the light source being located at least one lateral side of the light guide plate; and

a light source reflector above the reflector and surrounding the light source,

wherein the reflector and the heat dissipating layer have a length larger than a length of the light guide plate and are disposed directly below the light source reflector for absorbing the heat transferred to the light source reflector.

2. The backlight unit of claim 1, wherein the thermal conductive particles include a graphite powder.

3. The backlight unit of claim 1, wherein the heat dissipating layer is formed of a mixture including a graphite powder, a binder, and a curing agent.

4. The backlight unit of claim 3, wherein the mixture further includes a filler, a dispensing agent and a solvent.

5. The backlight unit of claim 3, wherein the heat dissipating layer is in contact with the first surface of the reflector.

6. The backlight unit of claim 5, wherein the first surface of the reflector is a bottom surface of the reflector, and a top surface of the reflector faces the light source for reflecting the light emitted from the light source.

7. The backlight unit of claim 1, further comprising:

a diffuser for diffusing the light from the light source; and

a prism sheet for condensing the light diffused by the diffuser.

8. The backlight unit of claim 1, wherein the light source is at least one of a cold cathode fluorescent lamp (CCFL), a light emitting diode (LED) and an external electrode fluorescent lamp (EEFL).

9. A method of manufacturing a heat dissipating layer of claim 1, the method comprising:

forming a mixture by mixing a graphite powder, a binder and a curing agent; and

forming the heat dissipating layer by applying the mixture onto a first surface of a reflector.

10. The method of claim 9, wherein the step of forming the mixture further includes mixing a filler, a dispersing agent and a solvent with the graphite powder, the binder and the curing agent.

11. A display device, comprising:

a display panel for displaying an image by using a light;

a light source for emitting a light;

a reflector below the light source for reflecting the light emitted from the light source and absorbing heat generated by the light source;

a heat dissipating layer including thermal conductive particles, the heat dissipating layer being disposed on and in direct contact with a first surface of the reflector for dissipating the heat transferred to the reflector;

a light guide plate for guiding the light emitted from the light source, the light source being located at least one lateral side of the light guide plate; and

a light source reflector above the reflector and surrounding the light source,

wherein the reflector and the heat dissipating layer have a length larger than a length of the light guide plate and are disposed directly below the light source reflector for absorbing the heat transferred to the light source reflector.

12. The display device of claim 11, wherein the thermal conductive particles include a graphite powder.

13. The display device of claim 11, wherein the heat dissipating layer is formed of a mixture including a graphite powder, a binder, and a curing agent.

14. The display device of claim 13, wherein the mixture further includes a filler, a dispersing agent and a solvent.

15. The display device of claim 13, wherein the heat dissipating layer is in contact with the first surface of the reflector.

16. The display device of claim 15, wherein the first surface of the reflector is a bottom surface of the reflector, and a top surface of the reflector faces the light source for reflecting the light emitted from the light source.

17. The display device of claim 11, wherein the display device is one of a liquid crystal display device (LCD), a plasma display device (PDP) and an organic electroluminescent device (OELD).