LIGHT EMITTING DIODE MODULE WITH IMPROVED LIGHT DISTRIBUTION UNIFORMITY

Abstract

In one embodiment, the invention is a light emitting diode module with improved light distribution uniformity. One embodiment of a signal head includes a light emitting diode and a reflector cup positioned to reflect light emitted by the light emitting diode, the reflector cup having a non-symmetrical curvature.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

So that the manner in which the above recited features of the present invention can be understood in detail, a more particular description of the invention, may be had by reference to embodiments, some of which are illustrated in the appended drawings. It is to be noted, however, that the appended drawings illustrate only typical embodiments of this invention and are therefore not to be considered limiting of its scope, for the invention may admit to other equally effective embodiments.

FIG. 1 depicts one embodiment of a traffic head assembly that may be adapted to benefit from the present invention;

FIG. 2 depicts a second embodiment of a traffic head assembly that may be adapted to benefit from the present invention;

FIGS. 3A and 3B depict a third embodiment of a traffic head assembly that may be adapted to benefit from the present invention;

FIG. 4 depicts one embodiment of a reflector optic;

FIG. 5 depicts a second embodiment of a reflector optic;

FIG. 6A depicts a third embodiment of a reflector optic;

FIG. 6B depicts a fourth embodiment of a reflector optic;

FIG. 7 is a graph depicting a representation of relative light intensity versus angular displacement, for light typically emitted from an LED;

FIG. 8 is a graph depicting a representation of relative light intensity versus angular displacement, for light typically emitted from an LED reflector optic without tilt and also for light typically emitted from an LED reflector optic with tilt;

FIG. 9 depicts an array of reflector optics with non-symmetric curvature;

FIG. 10 a depicts a second embodiment of an array of reflector optics with non-symmetric curvature;

FIGS. 10 b and 10c depict, respectively, side views of the array of FIG. 10a from a first edge and a second edge;

FIG. 11 a depicts a top perspective view of the array of reflector optics illustrated in FIGS. 10a-10c;

FIG. 11 b depicts a bottom perspective view of the array of reflector optics illustrated in FIGS. 10a-10c;

FIG. 12 a depicts a view of a single reflector cup in an array of reflector cups;

FIG. 12 b depicts a cross sectional view of the reflector cup of FIG. 12a taken along line 12b-12b of FIG. 12a;

FIG. 13 depicts the manner in which light is directed by the array of reflector cups of FIGS. 10a-10c.

Claims

1. A signal head, comprising: a light emitting diode; anda reflector cup positioned to reflect light emitted by the light emitting diode, the reflector cup having a non-symmetrical curvature.

2. The signal head of claim 1, further comprising: a first lens for collimating the light reflected by the reflector cup; anda second lens for distributing the light collimated by the first lens.

3. The signal head of claim 2, wherein the first lens is a Fresnel lens.

4. The signal head of claim 2, wherein the first lens and the second lens each have a diameter of approximately eight to twelve inches.

5. The signal head of claim 4, wherein a distance from the light emitting diode and the reflector cup to the first lens and the second lens is approximately three to four and one half inches.

6. The signal head of claim 1, wherein the reflector cup has a substantially conical shape.

7. The signal head of claim 6, wherein the substantially conical shape is one of: a hyperbola, a parabola, an ellipse, a sphere, an oblate sphere or a modified conic.

8. The signal head of claim 6, wherein the substantially conical shape has a faceted surface.

9. The signal head of claim 1, wherein the substantially conical shape satisfies:

10. The signal head of claim 1, wherein the reflector cup is formed of at least one of: a metal, a metallized surface, a reflectorized surface, a plastic or a glass.

11. The signal head of claim 1, wherein a first section of a perimeter of the reflector cup has a slope that is at least five degrees greater than a slope of a second section of the perimeter.

12. A method for illuminating a signal head, the method comprising: providing light via a light emitting diode; andreflecting light emitted by the light emitting diode via a reflector cup, the reflector cup having a non-symmetrical curvature.

13. The method of claim 12, further comprising: collimating the light reflected by the reflector cup using a first lens; anddistributing the light collimated by the first lens using a second lens.

14. The method of claim 13, wherein the first lens is a Fresnel lens.

15. The method of claim 13, wherein the first lens and the second lens each have a diameter of approximately eight to twelve inches.

16. The method of claim 15, wherein a distance from the light emitting diode and the reflector cup to the first lens and the second lens is approximately three to four and one half inches.

17. The method of claim 12, wherein the reflector cup has a substantially conical shape.

18. The method of claim 17, wherein the substantially conical shape is one of: a hyperbola, a parabola, an ellipse, a sphere, an oblate sphere or a modified conic.

19. The method of claim 17, wherein the substantially conical shape has a faceted surface.

20. The method of claim 17, wherein the substantially conical shape satisfies:

21. The method of claim 12, wherein the reflector cup is formed of at least one of: a metal, a metallized surface, a reflectorized surface, a plastic or a glass.

22. The method of claim 12, wherein a first section of a perimeter of the reflector cup has a slope that is at least five degrees greater than a slope of a second section of the perimeter.

23. A reflector optic for reflecting light emitted by an array of light-emitting diodes, the reflector optic comprising: a reflective surface; anda plurality of reflector cups formed in the reflective surface, each of the reflector cups having a non-symmetrical curvature designed to direct the emitted light away from a central axis.