SIGNAL LIGHT USING PHOSPHOR COATED LEDS

• US 20080170397A1
• Filed: 03/26/2008
• Published: 07/17/2008
• 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
• Granted Patent: US 7,918,582 B2
• Time in Patent Office: Days
• US Class Current: 362/244
• 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 signal light comprising:

a housing;

at least one outer lens; and

at least one or more second type of light emitting diodes (LEDs) deployed in the housing, wherein the at least one or more second type of LEDs comprises;

a pump;

a phosphor; and

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

wherein the at least one or more second type of LEDs has a pump peak wavelength less than or equal to 430 nm and has a phosphor with a peak wavelength greater than 575 nm.

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

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

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

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

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

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

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

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

10. The signal light of claim 1, wherein the one or more second type of LEDs are placed in a reflector.

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

12. The signal light of claim 1, wherein one or more first type of LEDs emitting a light energy having a second dominant wavelength are deployed in said housing.

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

14. The signal light of claim 1, comprising a colored or dichroic filter.

15. A method of creating a signal light, comprising:

providing a housing;

providing at least one outer lens; and

providing at least one or more second type of light emitting diodes (LEDs) deployed in the housing, wherein the at least one or more second type of LEDs comprises;

a pump;

a phosphor; and

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

wherein the at least one or more second type of LEDs has a pump peak wavelength less than or equal to 430 nm and has a phosphor with a peak wavelength greater than 575 nm.