Signal light using phosphor coated LEDs

• US 8,328,388 B2
• Filed: 04/04/2011
• Issued: 12/11/2012
• Est. Priority Date: 12/30/2005
• Status: Active Grant

• Current Assignee: Dialight Corporation (Dialight PLC)
• Original Assignee: Dialight Corporation (Dialight PLC)
• Inventors: Curran, John, Peck, John Patrick
• Primary Examiner(s): Alavi, Ali
• Application Number:
  US13/079,480
• Publication Number:
  US 20110182070A1
• Time in Patent Office: 617 Days
• Field of Search: 362/231, 362/84, 362/545
• US Class Current: 362/231
• CPC Class Codes: F21K 9/00 Light sources using semiconductor devices as light-generating elements, e.g. using light-emitting diodes [LED] or lasers
• CPC Class Codes: F21W 2111/02 for roads, paths or the like
• CPC Class Codes: F21Y 2115/10 Light-emitting diodes [LED]
• CPC Class Codes: Y10T 29/49002 Electrical device making

Abstract

An improved signal light and method for making an improved signal light is disclosed. For example, the improved signal light includes a housing, at least one outer lens and at least one or more second type of light emitting diodes (LEDs) deployed in the housing. The at least one or more second type of LEDs includes a pump, a phosphor and a filter having a cutoff point less than or equal to 540 nanometers (nm). The at least one or more second type of LEDs also has a pump peak wavelength less than or equal to 430 nm and has a phosphor with a peak wavelength greater than 575 nm.

Claims

1. A light emitting diode (LED) signal light comprising:

one or more LEDs, wherein the one or more LEDs comprises;

a pump;

a phosphor; and

a filter having a cutoff point less than or equal to 540 nanometers (nm),

wherein the one or more LEDs has a pump peak wavelength less than or equal to 430 nm and have a phosphor with a peak wavelength greater than 575 nm.

2. The LED signal light of claim 1, wherein the filter passes at least 70% of a light emitted from the one or more LEDs at about 600 nm.

3. The LED signal light of claim 1, wherein a light exiting the LED signal light has x and y coordinates in accordance with a 1931 CIE Chromaticity Diagram within the boundaries of:

4. The LED signal light of claim 1, wherein a light exiting the LED signal light has x and y coordinates in accordance with a 1931 CIE Chromaticity Diagram within the boundaries of:

5. The LED signal light of claim 1, wherein the one or more LEDs are made of Indium Gallium Nitride (InGaN).

6. The LED signal light of claim 1, wherein the phosphor is embedded in a ceramic plate and mounted over a LED die.

7. The LED signal light of claim 1, wherein the phosphor is bonded to a ceramic plate and mounted over a LED die.

8. The LED signal light of claim 1, wherein the phosphor includes yttrium aluminum garnet (YAG).

9. The LED signal light of claim 1, wherein the phosphor includes terbium aluminum garnet (TAG).

10. The LED signal light of claim 1, wherein the phosphor includes europium doped silicates.

11. The LED signal light of claim 1, wherein the one or more LEDs are placed in a reflector.

12. The LED signal light of claim 11, wherein the reflector is enclosed by a housing and an outer lens.

13. The LED signal light of claim 1, wherein a Fresnel lens is placed between the one or more LEDs and a housing.

14. The LED signal light of claim 1, wherein a second filter is used, wherein said second filter filters a light energy of the one or more LEDs such that a third dominant wavelength passes from the one or more LEDs.

15. The LED signal light of claim 1, wherein the filter comprises a colored or dichroic filter.

16. A method of creating a light emitting diode (LED) signal light, comprising:

providing one or more LEDs, wherein the one or more LEDs comprises;

a pump;

a phosphor; and

a filter having a cutoff point less than or equal to 540 nanometers (nm),

wherein the one or more LEDs have a pump peak wavelength less than or equal to 430 nm and have a phosphor with a peak wavelength greater than 575 nm.

17. The method of claim 16, wherein the filter passes at least 70% of a light emitted from the one or more LEDs at about 600 nm.

18. The method of claim 16, wherein the one or more LEDs are placed in a reflector.

19. The method of claim 16, wherein the phosphor is embedded in a ceramic plate and mounted over a LED die.

20. The method of claim 16, wherein the phosphor is bonded to a ceramic plate and mounted over a LED die.