Optic for Leds and Other Light Sources

• US 20080192477A1
• Filed: 08/16/2006
• Published: 08/14/2008
• Est. Priority Date: 08/17/2005
• Status: Active Grant

• Current Assignee: Illumination Management Solutions Incorporated (Eaton Corporation PLC.)
• Original Assignee: Illumination Management Solutions Incorporated (Eaton Corporation PLC.)
• Inventors: Holder, Ronald G., Rhoads, Greg
• Granted Patent: US 7,850,345 B2
• Time in Patent Office: Days
• US Class Current: 362/294
• CPC Class Codes: F21S 45/47 Passive cooling, e.g. using fins, thermal conductive elements or openings
• CPC Class Codes: F21V 29/76 with essentially identical parallel planar fins or blades, e.g. with comb-like cross-section
• CPC Class Codes: F21V 7/0008 providing for indirect lighting
• CPC Class Codes: F21V 7/0025 Combination of two or more reflectors for a single light source array of reflectors for a cluster of light sources F21V7/0083
• CPC Class Codes: F21Y 2115/10 Light-emitting diodes [LED]

Abstract

An LED lighting device comprises an LED light source; a thermal management element coupled to the LED light source to manage heat generated by the LED light source; a primary reflector with at least one reflective surface oriented to collect light from the LED light source and direct collected light into a first reflected beam; at least one central inclined reflector surface disposed to receive light from the LED light source; and at least one corresponding angled mirror surface disposed to collect light from the central inclined reflector surface and to direct the collected light into a second reflected beam (see FIG. 1).

Claims

1. An apparatus comprising:

an LED light source;

a thermal management element coupled to the LED light source to manage heat generated by the LED light source;

a primary reflector with at least one reflective surface oriented to collect light from the LED light source and direct collected light into a first reflected beam;

at least one central inclined reflector surface disposed to receive light from the LED light source; and

at least one corresponding angled mirror surface disposed to collect light from the central inclined reflector surface and to direct the collected light into a second reflected beam.

2. The apparatus of claim 1 where the first and second reflected beams are combined into a composite beam.

3. The apparatus of claim 2 where the first and second reflected beams are approximately parallel.

4. The apparatus of claim 1 where the primary reflector has an upper peripheral edge and where the angled mirror surface is disposed at or near the upper peripheral edge of the primary reflector to collect and redirect the energy from the central inclined reflector surface.

5. The apparatus of claim 1 where the LED is rearwardly directed and where the primary reflector comprises a parabolic reflector as defined by a surface of rotation facing the rearwardly directed LED.

6. The apparatus of claim 1 where the central inclined reflector surface comprises a parabolic surface of rotation.

7. The apparatus of claim 1 where the LED light source radiates energy in a peripheral forward solid angle, which energy is directed rearwardly into the primary reflector, is reflected by the primary reflector into a reflected beam, which is reflected forwardly in direction of the LED light source approximately along the centerline or optical axis of the primary reflector.

8. The apparatus of claim 2 where the LED light source radiates energy in a central solid angle, which energy would have been blocked by the LED light source when reflected, but for being included in a central forward solid angle of the composite beam.

9. The apparatus of claim 8 where the energy in the central forward solid angle of light radiated from the LED light source, which energy impinges on the central inclined reflector surface, is collected by the central inclined reflector surface and reflected to the angled mirror surface.

10. The apparatus of claim 9 where the angled mirror surface is oriented to reflect the energy directed to it into a beam that is approximately parallel or combined with the energy reflected from the primary reflector to form the composite beam.

11. The apparatus of claim 1 where the angled mirror surface has an optical axis and where the angled mirror surface is oriented such that its optical axis is a bisector of the angle between a second reflected light ray reflected from the angled mirror surface and a first reflected ray reflected from the central inclined reflector surface to the angled mirror surface, which first reflected ray is parallel to a centerline of the surface of rotation that defines the central inclined reflector surface.

12. The apparatus of claim 1 further comprising at least two inclined central reflector surfaces and at least two corresponding angled mirror surfaces, where the primary reflector has a first elliptical surface characterized by a first and second focus, where each inclined central reflector surface has a second elliptical surface, and where the LED light source is disposed at or near the first focus of the first elliptical surface of the primary reflector, where the shape and angular orientation of each of the inclined central reflector surfaces is defined by the second elliptical surface, and where each of the angled mirror surfaces is defined by a normal to the angled mirrored surface which normal is a bisector of the angle between a first ray reflected from the corresponding central inclined reflector surface to the corresponding angled mirror surface and a second ray reflected from the angled mirror surface to the second focus of the first elliptical surface of the primary reflector.

13. The apparatus of claim 1 further comprising at least two inclined central reflector surfaces and at least two corresponding angled mirror surfaces, where the primary reflector has a first parabolic surface characterized by a first focus, where each inclined central reflector surface has a second parabolic surface, and where the LED light source is disposed at or near the first focus of the first parabolic surface of the primary reflector, where the shape and angular orientation of each of the inclined central reflector surfaces is defined by the second parabolic surface, and where each of the angled mirror surfaces is defined by a normal to the angled mirrored surface which normal is a bisector of the angle between a first ray reflected from the corresponding central inclined reflector surface to the corresponding angled mirror surface and a second ray reflected from the angled mirror surface in a predetermined forward direction.

14. The apparatus of claim 12 where the second focus is defined at or near an end of an optic fiber.

15. The apparatus of claim 1 where a demarcation point is defined between the forward solid angle of energy from the LED light source and the peripheral forward solid angle of the LED light source at that point on the primary reflector where the reflected energy is blocked by the LED light source with substantially all the energy from the demarcation point to the optical axis of the LED light source being collected by the center inclined reflector surface.

16. The apparatus of claim 1 further comprising means for providing in combination with the LED light source, thermal management element, primary reflector, central inclined reflector surface and angled mirror surface, one of the group including a flashlight, head torch, automotive headlight, bicycle light, aircraft lighting, marine lighting, theater and stage lighting, general area lighting, fiber optic system, reading light, medical lighting, dental lighting or overhead task light.

17. A method comprising:

generating light from an LED light source;

reflecting light from the LED light source by a primary reflector with at least one reflective surface oriented to collect light from the LED light source and direct collected light into a first reflected beam;

reflecting light from the LED light source by at least one central inclined reflector surface to at least one corresponding peripherally positioned angled mirror surface; and

reflecting light from the angled mirror surface into a second reflected beam.

18. The method of claim 17 further combining the first and second reflected beams into a composite beam.

19. The method of claim 18 where combining the first and second reflected beams comprises combining the first and second reflected beams as approximately parallel beams.

20. The method of claim 17 where the primary reflector has an upper peripheral edge, where the angled mirror surface is disposed at or near the upper peripheral edge of the primary reflector and where reflecting light from the one central inclined reflector surface to at least one corresponding angled mirror surface comprises collecting and redirecting the energy from the central inclined reflector surface into a forward beam which is unobstructed by the LED light source.

21. The method of claim 17 where generating light from an LED light source comprises directing light rearwardly into the primary reflector, and where reflecting light from the LED light source from a primary reflector comprises forwardly reflecting light from a parabolic reflector as defined by a surface of rotation.

22. The method of claim 17 where reflecting light from the LED light source from at least one central inclined reflector surface comprises reflecting light from a parabolic surface of rotation into a peripheral direction toward the angled mirror surface.

23. The method of claim 17 where generating light from an LED light source comprising rearwardly radiating energy in a peripheral forward solid angle from the LED light source into the primary reflector, and where reflecting light from the LED light source from a primary reflector comprises forwardly reflecting the energy in a peripheral forward solid angle into a reflected beam approximately along a centerline or optical axis of the primary reflector.

24. The method of claim 18 where generating light from an LED light source comprises radiating energy in a central solid angle, which energy would have been at least partially blocked by the LED light source when reflected by the primary reflector, but for being included in the second reflected beam of the composite beam.

25. The method of claim 17 where reflecting light from the one central inclined reflector surface comprises reflecting light in a first reflected ray which is parallel to a centerline of the surface of rotation that defines the central inclined reflector surface and where reflecting light from the angled mirror surface into the second reflected beam comprises redirecting the light collected from the central inclined reflector surface into a forward beam.

26. The method of claim 17 where reflecting light from the LED light source by a primary reflector comprises reflecting light from the LED light source, which is disposed at or near a first focus of a first elliptical surface of the primary reflector, and which light is reflected by the first elliptical surface of the primary reflector, where reflecting light from the LED light source by at least one central inclined reflector surface comprises reflecting light by at least two second elliptical surfaces of two corresponding central inclined reflector surfaces to at least two corresponding angled mirror surfaces, and where reflecting light from the angled mirror surface into a second reflected beam comprises reflecting light from the angled mirror surface to a second focus of the first elliptical surface of the primary reflector.

27. The method of claim 17 where reflecting light from the LED light source by a primary reflector comprises reflecting light from the LED light source, which is disposed at or near a focus of a first parabolic surface of the primary reflector, and which light is reflected by the first parabolic surface of the primary reflector, where reflecting light from the LED light source by at least one central inclined reflector surface comprises reflecting light by at least two second parabolic surfaces of two corresponding central inclined reflector surfaces to at least two corresponding angled mirror surfaces, and where reflecting light from the angled mirror surface into a second reflected beam comprises reflecting light from the angled mirror surface in a predetermined forward direction.

28. The method of claim 27 where reflecting light from the LED light source by the first elliptical surface of the primary reflector comprises redirecting light to an end of an optic fiber, and where reflecting light from the angled mirror surface to a second focus of the first elliptical surface of the primary reflector comprises redirecting light to the end of the optic fiber.

29. The method of claim 17 where a demarcation point is defined between a forward solid angle of energy from the LED light source and the peripheral forward solid angle of the LED light source at that point on the primary reflector where the reflected energy is blocked by the LED light source where reflecting light from the LED light source by at least one central inclined reflector surface comprises collecting substantially all the energy from the demarcation point to the optical axis of the LED light source.