Constructive occlusion lighting system with ported cavity and fan structure

• US 6,286,979 B1
• Filed: 02/24/2000
• Issued: 09/11/2001
• Est. Priority Date: 02/24/2000
• Status: Expired due to Term

• Current Assignee: ABL IP Holding LLC (Acuity Brands, Inc.)
• Original Assignee: David P. Ramer, Jack C. Rains Jr, Matthew Brown
• Inventors: Brown, Matthew, Rains, Jack C. Jr., Ramer, David P.
• Primary Examiner(s): Sember, Thomas M.
• Assistant Examiner(s): Alavi, Ali
• Application Number:
  US09/512,086
• Time in Patent Office: 565 Days
• Field of Search: 362/297, 362/298, 362/301, 362/302, 362/303, 362/304, 362/305, 362/346
• US Class Current: 362/297
• CPC Class Codes: F21S 8/04 intended only for mounting on a ceiling or the like overhead structures F21S8/02 takes precedence; details of ceiling bases F21V21/03
• CPC Class Codes: F21V 11/02 using parallel laminae or strips, e.g. of Venetian-blind type F21V11/06 takes precedence
• CPC Class Codes: F21V 5/00 Refractors for light sources characterised by cooling arrangements F21V29/504
• CPC Class Codes: F21V 7/0016 on lighting devices that also provide for direct lighting, e.g. by means of independent light sources, by splitting of the light beam, by switching between both lighting modes
• CPC Class Codes: F21V 7/09 with a combination of different curvatures

Abstract

An optical integrating cavity supplies light or other radiant energy through a port to a deflector. The deflector coupled to the port may form a “fan” extending along one side or around all or part of the circumference of the cavity. Preferred embodiments use principles of constructive occlusion (diffuse reflectivity in a mask and cavity structure) together with the port and deflector structure. The cavity and mask serve as the optical integrating cavity. The constructive occlusion provides a tailored intensity distribution for radiant energy illuminating a first region; whereas the integrating cavity, port and deflector distribute another portion of the electromagnetic energy over a second field of intended illumination. The first and second areas illuminated may overlap slightly, or one may include the other, but preferably most of the two areas are separate. In some cases, the system configuration creates a dead zone between the two regions.

Claims

1. A lighting system, comprising:

a diffusely reflective optical-integrating cavity;

a source coupled to emit light into the cavity;

an elongated port extending along a portion of a perimeter of the cavity, for providing a passage for light from within the cavity;

a first reflector mounted along the portion of the perimeter of the cavity, the first reflector having a reflective surface extending at a first angle from a first elongated edge of the port toward a region to be illuminated;

a second reflector mounted along the portion of the perimeter of the cavity, the second reflector having a reflective surface extending at a second angle from a second elongated edge of the port toward the region to be illuminated;

the reflective surfaces of the first and second reflectors forming a fan-shaped deflector coupled to the port and expanding outward as the reflective surfaces extend from the edges of the port toward the region to be illuminated, for directing the light from within the cavity over the region to be illuminated.

2. A lighting system as in claim 1, wherein the diffusely reflective optical-integrating cavity approximates an integrating sphere.

3. A lighting system as in claim 1, wherein the diffusely reflective optical-integrating cavity comprises two semi-spherical domes having diffusely reflective inner surfaces.

4. A lighting system as in claim 1, wherein the diffusely reflective optical-integrating cavity comprises two quarter-spherical domes having diffusely reflective inner surfaces and a reflective wall abutting edges of the domes.

5. A lighting system as in claim 1, wherein the diffusely reflective optical-integrating cavity comprises a base, a mask and a diffusely reflective cavity formed in the base or the mask configured to provide constructive occlusion illumination of another region.

6. A lighting system as in claim 1, further comprising:

another port for providing a passage for light from within the cavity; and

another deflector coupled to said another port for directing light from said another port over another region to be illuminated.

7. A lighting system as in claim 6, further comprising:

a third port for providing a passage for light from within the cavity; and

a third deflector coupled to said third port for directing light from said third port over a third region to be illuminated.

8. A lighting system, comprising:

a cavity having a diffusely reflective inner surface and an aperture;

a light source coupled to the cavity, for emitting light into an area within the cavity;

a mask positioned outside the cavity at a distance from the aperture, the mask having a reflective surface optically facing the aperture, the mask constructively occluding the aperture of the cavity with respect to a first field of intended illumination, such that light reflected between the mask and cavity and emerging from a gap between the mask and the aperture illuminates a substantial portion of the first field of intended illumination with a desired intensity distribution pattern;

a port extending from the diffusely reflective inner surface of the cavity toward a second field of intended illumination; and

a reflector optically coupled to the port, for directing light emerging through the port toward the second field of intended illumination.

9. A lighting system as in claim 8, wherein the second field of intended illumination includes a substantial area outside the first field of intended illumination.

10. A lighting system as in claim 8, wherein the second field of intended illumination includes portion of the first field of intended illumination.

11. A system for projecting electromagnetic radiation with predetermined intensity over two distinct regions, comprising:

a base having a defined area substantially facing a first region to be illuminated with the electromagnetic radiation, the defined area of the base having a reflective characteristic with respect to the electromagnetic radiation;

a shoulder adjacent to and extending along a substantial portion of the defined area of the base, the shoulder having a surface with a reflective characteristic with respect to the electromagnetic radiation facing toward at least a portion of the first region to be illuminated;

a mask between the base and the first region to be illuminated at a predetermined distance from the defined area of the base, said mask having a defined area substantially facing the defined area of the base, the defined area of the mask having a reflective characteristic with respect to the electromagnetic radiation;

a source configured to emit the electromagnetic radiation for reflection between the defined areas of the base and mask, such that the base, mask and shoulder emit a substantial first portion of the electromagnetic radiation with a tailored intensity distribution of electromagnetic radiation over the first region to be illuminated;

a port providing a radiation coupling from one of the defined areas toward a second region to be illuminated with the electromagnetic radiation; and

a deflector having at least one reflective inner surface extending from a narrow end of the deflector coupled to the port to a wide end of the deflector directed toward the second region to be illuminated, such that a second portion of the electromagnetic radiation emerging through the port and deflector illuminates the second region.

12. A system as in claim 11, wherein the second region to be illuminated includes a substantial area outside the first region to be illuminated.

13. A system as in claim 11, wherein the second region to be illuminated includes a portion of the first region to be illuminated.

14. A system as in claim 11, wherein the second region to be illuminated is located entirely within the first region to be illuminated.

15. A system as in claim 11, wherein the defined area of the base comprises an aperture of a diffusely reflective cavity formed in the base.

16. A system as in claim 11, wherein the defined area of the mask comprises an aperture of a diffusely reflective cavity formed in the mask, and the defined area of the base comprises an area reflecting electromagnetic radiation emerging from the cavity through the aperture.

17. A system as in claim 11, wherein the surface of the shoulder is inclined at an angle from the defined area of the base toward the first region to be illuminated.

18. A system as in claim 11, wherein the deflector directs the second portion of the electromagnetic radiation away from the first region to be illuminated such that the shoulder and the deflector create a dead zone of little or no illumination by the system between the first and second regions.

19. A system as in claim 11, wherein:

the port comprises an elongated opening extending along at least a portion of the periphery of the base; and

the deflector forms a fan-shaped structure extending along the elongated opening.

20. A system as in claim 11, wherein the port extends from the defined area of the base toward the second region to be illuminated.

21. A system as in claim 11, wherein the port extends from the defined area of the mask toward the second region to be illuminated.

22. A system for projecting electromagnetic radiation, comprising:

a source emitting the electromagnetic radiation;

a base comprising a cavity optically coupled to receive the electromagnetic radiation from the source, the cavity having an inner surface with a substantially diffuse reflective characteristic with respect to the electromagnetic radiation and having an opening, a perimeter of the opening of the cavity forming an aperture substantially facing a first region to be illuminated with a first portion of the electromagnetic radiation;

a shoulder adjacent to and extending along a substantial portion of the aperture, the shoulder having a surface with a reflective characteristic with respect to the electromagnetic radiation facing toward at least a portion of the first region to be illuminated;

a mask between the base and the first region to be illuminated at a predetermined distance from the aperture, the mask having a surface area substantially facing the aperture which has a reflective characteristic with respect to the electromagnetic radiation, the mask having a relationship to the aperture such that the mask, cavity and shoulder provide a tailored intensity distribution of the first portion of the electromagnetic radiation over the first region;

a port extending through the base from the cavity toward a second region to be illuminated with a second portion of the electromagnetic radiation, the second region including a substantial area outside the first region to be illuminated; and

a deflector, having a reflective inner surface, extending from a narrow end coupled to the port to a wide end directed toward the second region to be illuminated.

23. A system for projecting electromagnetic radiation as in claim 22, wherein the source comprises a visible light source.

24. A system for projecting electromagnetic radiation as in claim 22, wherein at least a portion of the surface of the shoulder exhibits a substantially diffuse reflective characteristic.

25. A system for projecting electromagnetic radiation as in claim 22, wherein at least a portion of the surface of the shoulder exhibits a substantially specular reflective characteristic.

26. A system for projecting electromagnetic radiation as in claim 22, wherein the surface area of the mask substantially facing the aperture has a substantially diffuse reflective characteristic.

27. A system for projecting electromagnetic radiation as in claim 22, wherein at least a substantial portion of the inner surface of the deflector has a substantially specular reflective characteristic.

28. A system for projecting electromagnetic radiation as in claim 22, wherein the port and deflector are directed at such an angle away from the first region to be illuminated as to create a dead zone of substantially no illumination by the system between the first and second regions to be illuminated.

29. A system for projecting electromagnetic radiation as in claim 22, wherein the cavity is substantially hemispherical, and the port comprises an annular opening extending around the hemispherical cavity about an axis through the cavity, the aperture and the mask.

30. A system for projecting electromagnetic radiation as in claim 29, wherein the deflector forms a fan structure encircling the annular opening.

31. A system for projecting electromagnetic radiation as in claim 22, wherein the mask comprises a curved reflector for reflecting light from the source substantially toward the cavity.

32. A system for projecting electromagnetic radiation as in claim 31, wherein the source comprises a lamp mounted within a volume substantially enclosed by the cavity and the curved reflector.

33. A system for projecting electromagnetic radiation as in claim 22, further comprising:

another port extending through the base from the cavity toward a third region to be illuminated with a third portion of the electromagnetic radiation; and

another deflector having a reflective inner surface extending from a narrow end coupled to the other port to a wide end directed toward the third region to be illuminated.

34. A system for projecting electromagnetic radiation as in claim 33, wherein:

the port comprises an elongated opening along a first side of the cavity; and

the other port comprises an opening along a second side of the cavity substantially opposite the first side of the cavity.

35. A system as in claim 34, wherein each of the deflectors comprises a fan-shaped structure constructed along one of the elongated openings.

36. A system as in claim 34, wherein the inner surface of the cavity comprises a segment of a cylinder.

37. A system as in claim 36, wherein the source comprises a tubular lamp located between the mask and the inner surface of the cavity.

38. A system for projecting electromagnetic radiation, comprising:

a source emitting the electromagnetic radiation;

a base comprising a cavity optically coupled to receive the electromagnetic radiation from the source, the cavity having an inner surface with a substantially diffuse reflective characteristic with respect to the electromagnetic radiation and having an opening, a perimeter of the opening of the cavity forming an aperture substantially facing a first region to be illuminated with a first portion of the electromagnetic radiation;

a port coupled to one of the defined areas and extending toward a second region to be illuminated with the electromagnetic radiation; and

a deflector having at least one reflective inner surface extending from the port toward the second region to be illuminated, such that a second portion of the electromagnetic radiation emerging through the port and deflector illuminates the second region.

39. A system as in claim 38, wherein said at least one reflective inner surface of the deflector extends from a narrow end of the deflector coupled to the port to a wide end of the deflector directed toward the second region to be illuminated.

40. A system as in claim 38, wherein the deflector comprises a solid member providing total internal reflection from sides extending along the length of the solid member between an end coupled to the port and an end facing substantially toward the second region to be illuminated.