Apparatus for providing a light source that combines different color LEDS

• US 7,777,322 B2
• Filed: 12/29/2006
• Issued: 08/17/2010
• Est. Priority Date: 12/30/2005
• Status: Active Grant

• Current Assignee: Dialight Corporation (Dialight PLC)
• Original Assignee: Dialight Corporation (Dialight PLC)
• Inventors: Curran, John W., Peck, John Patrick, Goldstein, Peter
• Primary Examiner(s): Dang; Phuc T
• Application Number:
  US11/618,552
• Publication Number:
  US 20070164268A1
• Time in Patent Office: 1,327 Days
• Field of Search: 257/678, 257/686, 257/693, 257/E25.032, 257/E33.056, 359/618, 359/634
• US Class Current: 257/686
• CPC Class Codes: F21V 3/00 Globes; Bowls; Cover glasses with refracting properties F21V5/00; with reflecting properties F21V7/00; characterised by cooling arrangements F21V29/506
• CPC Class Codes: F21V 5/045 the lens having discontinuous faces, e.g. Fresnel lenses
• CPC Class Codes: F21V 9/08 for producing coloured light, e.g. monochromatic; for reducing intensity of light with provision for controlling the colour F21V9/40
• CPC Class Codes: F21W 2111/00 Use or application of lighting devices or systems for signalling, marking or indicating, not provided for in codes F21W2102/00 – F21W2107/00
• CPC Class Codes: F21W 2111/02 for roads, paths or the like
• CPC Class Codes: F21Y 2105/10 comprising a two-dimensional array of point-like light-generating elements
• CPC Class Codes: F21Y 2105/12 characterised by the geometrical disposition of the light-generating elements, e.g. arranging light-generating elements in differing patterns or densities
• CPC Class Codes: F21Y 2113/13 comprising an assembly of point-like light sources
• CPC Class Codes: F21Y 2115/10 Light-emitting diodes [LED]
• CPC Class Codes: H05B 45/00 Circuit arrangements for operating light-emitting diodes [LED]
• CPC Class Codes: H05B 45/20 Controlling the colour of the light

Abstract

A method for creating an improved signal light is disclosed. For example, the improved signal light includes a housing, one or more first type of light emitting diodes (LEDs) emitting a light energy having a first dominant wavelength deployed in the housing, one or more second type of LEDs emitting a light energy having a second dominant wavelength deployed in the housing, a filter and a mixer. The filter may filter the light energy of the one or more second type of LEDs such that only a third dominant wavelength passes from the one or more second type of LEDs. The mixer may mix the light energy having the first dominant wavelength and the filtered light energy having the third dominant wavelength to form a light energy having a desired fourth dominant wavelength.

Claims

1. A signal light comprising:

a housing;

one or more first type of light emitting diodes (LEDs) emitting a light energy having a first dominant wavelength deployed in said housing;

one or more second type of LEDs emitting a light energy having a second dominant wavelength deployed in said housing, wherein said one or more second type of LEDs comprise a blue LED coated with a yellow phosphor;

a filter, wherein said filter filters said light energy of said one or more second type of LEDs such that only a third dominant wavelength passes from said one or more second type of LEDs; and

a mixer, wherein said mixer mixes said light energy having said first dominant wavelength and said filtered light energy having said third dominant wavelength to form a light energy having a desired fourth dominant wavelength.

2. The signal light of claim 1, comprising:

an outer lens attached to said housing, wherein said filter and said mixer are integrated into said outer lens.

3. The signal light of claim 2, wherein said outer lens comprises a scattered surface to mix said light energy having said first dominant wavelength and said filtered light energy having said third dominant wavelength.

4. The signal light of claim 1, wherein said filter is located between said one or more first and second type of LEDs and at least one lens.

5. The signal light of claim 1, wherein said filter is located directly on each one of said one or more second type of LEDs.

6. The signal light of claim 1, wherein said filter is a colored filter or dichroic filter.

7. The signal light of claim 1, wherein said mixer is deployed in a Fresnel lens and said filter is deployed in an outer lens.

8. The signal light of claim 1, wherein said mixer and said filter are deployed in a Fresnel lens.

9. The signal light of claim 1, wherein said filter is deployed in a Fresnel lens.

10. The signal light of claim 9, wherein said outer lens diffracts light into a desired angular direction.

11. The signal light of claim 1, wherein said one or more first type of LEDs comprise aluminum indium gallium phosphide (AIInGaP) and said one or more second type of LEDs comprise indium gallium nitride (InGaN).

12. The signal light of claim 1, wherein said first dominant wavelength is approximately 595 nanometers having an orange-yellow color.

13. The signal light of claim 12, wherein said light energy having said first dominant wavelength comprises x and y coordinates in accordance with a 1931 CIE Chromaticity Diagram within boundaries of:

x y 0.3 0.2 0.2 0.3 0.4 0.5 0.5 0.4 0.3 0.2.

14. The signal light of claim 1, wherein said third dominant wavelength is approximately 580 nanometers having a yellow-green color.

15. The signal light of claim 14, wherein said light energy having said third dominant wavelength comprises x and y coordinates in accordance with a 1931 CIE Chromaticity Diagram within boundaries of:

x y 0.4 0.6 0.4 0.5 0.5 0.4 0.55 0.45 0.4 0.6.

16. The signal light of claim 1, wherein said fourth dominant wavelength is approximately 590 nanometers having a yellow color.

17. The signal light of claim 16, wherein said light energy of said desired fourth wavelength comprises x and y coordinates in accordance with a 1931 CIE Chromaticity Diagram within boundaries of:

x y 0.53 0.47 0.51 0.47 0.59 0.39 0.61 0.39 0.53 0.47.

18. A signal light comprising:

a housing;

one or more light emitting diodes (LEDs) emitting a light energy having a dominant wavelength of approximately 595 nanometers (nm) deployed in said housing;

one or more LEDs emitting a light energy having a dominant wavelength of approximately 450 nm deployed in said housing;

a filter, wherein said filter filters said light energy of said one or more LEDs having a dominant wavelength of approximately 450 nm such that only a light energy having a dominant wavelength of approximately 580 nm passes; and

a mixer, wherein said mixer mixes said light energy having said dominant wavelength of approximately 595 nm and said light energy having said dominant wavelength of approximately 580 nm to form a light energy having a dominant wavelength of approximately 590 nm.

19. A signal light comprising:

a housing;

one or more first type of light emitting diodes (LEDs) emitting a light energy having a first dominant wavelength deployed in said housing;

one or more second type of LEDs emitting a light energy having a second dominant wavelength deployed in said housing;

a filter, wherein said filter filters said light energy of said one or more second type of LEDs such that only a third dominant wavelength passes from said one or more second type of LEDs; and

a mixer, wherein said mixer mixes said light energy having said first dominant wavelength and said filtered light energy having said third dominant wavelength to form a light energy having a desired fourth dominant wavelength, wherein said mixer is deployed in a Fresnel lens and said filter is deployed in an outer lens.

20. A signal light comprising:

a housing;

one or more first type of light emitting diodes (LEDs) emitting a light energy having a first dominant wavelength deployed in said housing;

one or more second type of LEDs emitting a light energy having a second dominant wavelength deployed in said housing;

a filter, wherein said filter filters said light energy of said one or more second type of LEDs such that only a third dominant wavelength passes from said one or more second type of LEDs; and

a mixer, wherein said mixer mixes said light energy having said first dominant wavelength and said filtered light energy having said third dominant wavelength to form a light energy having a desired fourth dominant wavelength, wherein said mixer and said filter are deployed in a Fresnel lens.

21. A signal light comprising:

a housing;

one or more first type of light emitting diodes (LEDs) emitting a light energy having a first dominant wavelength deployed in said housing;

one or more second type of LEDs emitting a light energy having a second dominant wavelength deployed in said housing;

a filter, wherein said filter filters said light energy of said one or more second type of LEDs such that only a third dominant wavelength passes from said one or more second type of LEDs; and

a mixer, wherein said mixer mixes said light energy having said first dominant wavelength and said filtered light energy having said third dominant wavelength to form a light energy having a desired fourth dominant wavelength, wherein said filter is deployed in a Fresnel lens.

22. The signal light of claim 21, wherein said outer lens diffracts light into a desired angular direction.