LED traffic light with individual LED reflectors

• US 6,283,613 B1
• Filed: 07/29/1999
• Issued: 09/04/2001
• Est. Priority Date: 07/29/1999
• Status: Expired due to Term

• Current Assignee: Eaton Intelligent Power Limited (Eaton Corporation PLC.)
• Original Assignee: Cooper Technologies Company (Eaton Corporation PLC.)
• Inventors: Schaffer, Irving
• Primary Examiner(s): O'Shea, Sandra
• Assistant Examiner(s): Zeade, Bertrand
• Application Number:
  US09/362,878
• Time in Patent Office: 768 Days
• Field of Search: 362/245, 362/247, 362/800, 362/554, 362/545, 362/328, 362/329, 362/339, 116/63.R, 116/63.P
• US Class Current: 362/245
• CPC Class Codes: F21V 13/04 the elements being reflectors and refractors for vehicle rear lights F21S43/40
• CPC Class Codes: F21V 7/0083 Array of reflectors for a cluster of light sources, e.g. arrangement of multiple light sources in one plane combination of two or more reflectors F21V7/0025
• 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: G02B 3/0056 arranged along two different directions in a plane, e.g. honeycomb arrangement of lenses G02B3/0043 takes precedence; miniaturised objectives for electronic devices employing wafer level optics G02B13/0085
• CPC Class Codes: G02B 3/08 with discontinuous faces, e.g. Fresnel lens diffractive Fresnel lenses G02B5/1876
• CPC Class Codes: G08G 1/095 Traffic lights
• CPC Class Codes: H01L 33/60 Reflective elements
• CPC Class Codes: Y10S 362/80 Light emitting diode

Abstract

An LED signal module includes a casing defining a cavity. Within the cavity is an array of LEDs. Individual reflectors are placed around individual LEDs of the array. The individual reflectors are structured to receive direct light from their associated individual LEDs and substantially to prevent direct light from their associated individual LEDs from impinging upon the individual reflectors of other LEDs of the array of LEDs. Also included, and covering the cavity, is a lens shaped to direct the output luminance of the LEDs below a horizontal axis of the module.

Claims

1. A signal light module comprising:

a casing defining a cavity;

an array of LEDs positioned in the cavity;

individual reflectors positioned around individual LEDs of the array of LEDs, the individual reflectors being structured to receive direct light from their associated individual LEDs and substantially to prevent direct light from their associated individual LEDs from impinging upon the individual reflectors of other LEDs of the array of LEDs; and

a lens covering the cavity and shaped to concentrate the output luminance of the LEDs below a horizontal axis of the module.

2. The module of claim 1, wherein the lens is clear and the LEDs are operable to emit light having a desired signal color.

3. The module of claim 1, wherein the individual reflectors comprise conic reflectors.

4. The module of claim 1, wherein the individual reflectors comprise parabolic reflectors.

5. The module of claim 1, wherein the individual reflectors are formed as parts of an insert which fits over the LED array and includes holes sized and positioned to integrate each LED with its corresponding reflector.

6. The module of claim 1, wherein the outer surface of the lens has a flat shape.

7. The module of claim 1, wherein the outer surface of the lens has a dome-shaped curvature.

8. The module of claim 1, wherein the lens includes an inner surface having optical detail necessary to position an individual fresnel lens along an optical axis of each LED.

9. The module of claim 8, wherein a fresnel lens comprises three facets, two in an upper region of the lens and one in a lower region of the lens, the upper region being configured to refract upward moving light downward below the horizontal axis, and the lower region being configured to refract light passing through it slightly towards the downward direction.

10. The module of claim 8, wherein the lens has a smooth outer surface.

11. The signal module of claim 1, wherein the lens has a diameter of about eight inches and the module includes less than 80 LEDs.

12. The signal module of claim 1, wherein the lens has a diameter of about twelve inches and the module includes less than 160 LEDs.

13. A traffic light including one or more of the modules of claim 1.

14. The traffic light of claim 13, wherein a module lens includes an inner surface having optical detail necessary to position an individual fresnel lens along an optical axis of each LED.

15. The traffic light of claim 14, wherein a fresnel lens comprises three facets, two in an upper region of the lens and one in a lower region of the lens, the upper region being configured to refract upward moving light downward below the horizontal axis, and the lower region being configured to have a neutral effect upon the direction of light propagating through it.

16. The traffic light of claim 14, wherein a lens has a smooth outer surface.

17. A method of making a signal light module, the method comprising:

positioning an array of LEDs in a casing;

positioning individual reflectors around individual LEDs of the array, the individual reflectors being structured to receive direct light from their associated individual LEDs and substantially to prevent direct light from their associated individual LEDs from impinging upon the individual reflectors of other LEDs of the array of LEDs; and

covering the cavity with a lens, the lens being shaped to produce a signal concentrated below a horizontal plane in which the signal module lies and providing generally uniform luminosity when viewed from below the horizontal plane.