FLICKERLESS LIGHT SOURCE

• US 20080298080A1
• Filed: 05/30/2007
• Published: 12/04/2008
• Est. Priority Date: 05/30/2007
• Status: Active Grant

• Current Assignee: Pixon Technologies Corp.
• Original Assignee: Pixon Technologies Corp.
• Inventors: Wu, Rong-Yaw, Hsu, Ai-Lan
• Granted Patent: US 7,478,941 B2
• Time in Patent Office: Days
• US Class Current: 362/555
• CPC Class Codes: F21K 9/27 Retrofit light sources for lighting devices with two fittings for each light source, e.g. for substitution of fluorescent tubes
• CPC Class Codes: F21K 9/61 using light guides
• CPC Class Codes: F21Y 2115/10 Light-emitting diodes [LED]
• CPC Class Codes: G02B 17/006 Systems in which light light is reflected on a plurality of parallel surfaces, e.g. louvre mirrors, total internal reflection [TIR] lenses Fresnel mirrors G02B5/09, Fresnel lenses G02B3/08
• CPC Class Codes: G02B 5/021 the diffusion taking place at the element's surface, e.g. by means of surface roughening or microprismatic structures
• CPC Class Codes: G02B 6/001 the light being emitted along at least a portion of the lateral surface of the fibre

Abstract

A flickerless light source comprising a transparent or semitransparent diffuser, a lightpipe with a patterned surface inside the diffuser, and an LED light source attached to each end of the lightpipe is disclosed. The patterned surface of the lightpipe diffuses or reflects light emitted by the LED light sources and through the lightpipe to provide a light with uniform brightness and intensity. The lightpipe is coated with a thin layer of visible-light transparent material which is doped with organic dye molecules. The organic dye has strong ultraviolet light absorption characteristics. By changing the doping concentration of the dye molecules the coating can become total opaque or semi-transparent to certain wavelengths and selective wavelength conversion is obtained. In this way light color, brightness, and intensity can be varied or controlled.

Claims

1. A light source comprising:

a diffuser;

a lightpipe inside the diffuser; and

at least one light emitting diode light source attached to the diffuser.

2. The light source of claim 1, the lightpipe comprising a patterned surface for diffusing or reflecting light.

3. The light source of claim 1, where one light emitting diode light source is attached to each end of the diffuser.

4. The light source of claim 1, the light emitting diode light source comprising:

at least one light emitting diode;

a housing for holding the at least one light emitting diode; and

an electrical connector for allowing power to be applied to the at least one light emitting diode from a power source.

5. The light source of claim 1, the lightpipe comprising a coating of visible-light transparent material doped with organic dye molecules.

6. The light source of claim 1, the lightpipe comprising an organic dye coating with ultraviolet light absorption characteristics.

7. The light source of claim 1, the lightpipe comprising a coating for selective wavelength conversion.

8. The light source of claim 7, the coating comprising a visible-light transparent material doped with organic dye molecules.

9. A light source comprising:

a diffuser;

a lightpipe inside the diffuser, the lightpipe comprising a patterned surface for diffusing or reflecting light; and

at least one light emitting diode light source attached to the diffuser.

10. The light source of claim 9, where one light emitting diode light source is attached to each end of the diffuser.

11. The light source of claim 9, the light emitting diode light source comprising:

at least one light emitting diode;

a housing for holding the at least one light emitting diode; and

an electrical connector for allowing power to be applied to the at least one light emitting diode from a power source.

12. The light source of claim 9, the lightpipe comprising a coating of visible-light transparent material doped with organic dye molecules.

13. The light source of claim 9, the lightpipe comprising an organic dye coating with ultraviolet light absorption characteristics.

14. The light source of claim 9, the lightpipe comprising a coating for selective wavelength conversion.

15. The light source of claim 14, the coating comprising a visible-light transparent material doped with organic dye molecules.

16. A light source comprising:

a hollow diffuser tube;

a lightpipe inside the hollow diffuser tube, the lightpipe comprising a patterned surface for diffusing light; and

a light emitting diode light source attached to each end of the hollow diffuser tube.

17. The light source of claim 16, the light emitting diode light source comprising:

at least one light emitting diode;

a housing for holding the at least one light emitting diode; and

an electrical connector for providing power to the at least one light emitting diode from a power source.

18. The light source of claim 16, the lightpipe comprising a coating of visible-light transparent material doped with organic dye molecules.

19. The light source of claim 16, the lightpipe comprising an organic dye coating with ultraviolet light absorption characteristics.

20. The light source of claim 19, the coating comprising a visible-light transparent material doped with organic dye molecules.

21. A flickerless light source comprising:

a diffuser;

a lightpipe with patterned surface inside the diffuser for diffusing or reflecting light; and

a light emitting diode light source attached to the lightpipe.

22. The flickerless light source of claim 21, the light emitting diode light source further comprising:

an electrical connector for allowing power to be applied to the light emitting diode light source from a power source.

23. The flickerless light source of claim 22, the electrical connector shaped to match a socket of a conventional incandescent light fixture.