Enhancements in radiant energy transducer systems

• US 6,342,695 B1
• Filed: 02/18/2000
• Issued: 01/29/2002
• Est. Priority Date: 03/31/1998
• Status: Expired due to Term

• Current Assignee: ABL IP Holding LLC (Acuity Brands, Inc.)
• Original Assignee: Advanced Optical Technologies, LLC
• Inventors: Rains, Jack C. Jr., Ramer, David P., Bagwell, Richard S.
• Primary Examiner(s): Kim, Robert H.
• Assistant Examiner(s): THOMAS, COURTNEY D
• Application Number:
  US09/506,385
• Time in Patent Office: 711 Days
• Field of Search: 250/227.24, 250/228, 250/237.R, 250/214.R, 362/298, 362/301, 362/351
• US Class Current: 250/214.00R
• CPC Class Codes: G01D 5/264 Mechanical constructional elements therefor G01D5/28, G01D5/32, G01D5/39 and G01D5/40 take precedence; Mechanical adjustment thereof
• CPC Class Codes: G01J 1/02 Details
• CPC Class Codes: G01J 1/0266 Field-of-view determination; Aiming or pointing of a photometer; Adjusting alignment; Encoding angular position; Size of the measurement area; Position tracking; Photodetection involving different fields of view for a single detector
• CPC Class Codes: G01J 1/04 Optical or mechanical part supplementary adjustable parts
• CPC Class Codes: G01J 1/0414 using plane or convex mirrors, parallel phase plates, or plane beam-splitters
• CPC Class Codes: G01J 1/0422 using light concentrators, collectors or condensers
• CPC Class Codes: G01J 1/0425 using optical fibers
• CPC Class Codes: G01J 1/0474 Diffusers cavities G01J2001/0481
• CPC Class Codes: G01J 1/06 Restricting the angle of incident light

Abstract

Many applications of radiant energy transducer systems call for specific performance characteristics over predetermined fields or surfaces. Constructive occlusion utilizes diffuse reflectivity and a mask sized/positioned to occlude an active optical area, such as an aperture of a reflective cavity, to provide tailored performance characteristics. Constructive occlusion alone or in combination with other techniques enable tailoring of the performance of a radiant energy transducer system to meet requirements of specific applications. One mechanism used to further tailor performance involves a non-diffuse reflective shoulder along a peripheral section of the mask and cavity system. Another technique involves using a retro-reflective surface, for example along a portion of the periphery of the system. Another technique involves use of a reflective wall along one side of the system, to limit the field of view to angles on the opposite side of the axis of the mask and cavity configuration.

Claims

1. A radiant energy transducing system, comprising:

a base having a diffuse active optical area which faces substantially toward at least a portion of an intended field of view of the system;

a mask spaced from the base and positioned to occlude a portion of the active optical area of the base, a reflective surface of the mask facing substantially toward the active optical area of the base;

a diffusely reflective cavity formed in one of the active optical area of the base and the surface of the mask;

a first reflective wall extending from a side of the cavity to an edge of the other one of the active optical area of the base and the surface of the mask;

a shoulder adjacent to and extending outward from a peripheral section of the active optical area of the base and having a reflective surface facing the field of view;

a second reflective wall extending from a periphery of the mask away from the base; and

an electromagnetic transducer for transducing between radiant energy associated with the active optical area and corresponding electrical signals,

wherein the mask has a size in relation to the active optical area and is spaced a distance from the active optical area such that the system exhibits a predetermined performance characteristic with respect to the radiant energy over the intended field of view.

2. A system as in claim 1, wherein the cavity comprises a segment of a sphere or a segment of a cylinder.

3. A system as in claim 1, wherein at least one of the reflective walls has a substantially specular reflective characteristic.

4. A system as in claim 1, wherein the first reflective wall has a substantially diffuse reflective characteristic.

5. A system as in claim 1, wherein the reflective surface of the shoulder has a substantially specular reflective characteristic.

6. A system as in claim 1, wherein the first reflective wall and the second reflective wall are substantially coplanar.

7. A system as in claim 1, wherein the first reflective wall and the second reflective wall are not coplanar.

8. A system as in claim 7, wherein the second reflective wall extends from an outer edge of the mask in a direction away from the base.

9. A system as in claim 8, wherein the second reflective wall has a substantially specular reflective characteristic.

10. A system as in claim 8, wherein the first reflective wall comprises a curved section formed integral with at least one of the active optical area of the base and the surface of the mask.

11. A system as in claim 1, further comprising a retro-reflector arranged on a periphery of the system to redirect radiant energy directed by system components toward an area outside the intended field of view back into the system.

12. A system as in claim 11, wherein the retro-reflector is arranged along a periphery of the shoulder at a distance from the active optical area of the base.

13. A system as in claim 11, wherein the retro-reflector is arranged substantially opposite the active area of the base and at a distance from the mask at least along an axis of the active area and the mask, a retro-reflective surface of the retro-reflector facing substantially toward the base and the mask.

14. A system as in claim 1, wherein the cavity is formed in the mask.

15. A system as in claim 14, further comprising a substantially j-shaped substrate, wherein reflective surfaces of the shoulder, active area of the base, first wall and cavity comprise a diffusely reflective coating on appropriate sections of the j-shaped substrate.

16. A system as in claim 1, wherein the cavity is formed in the base, and the aperture of the cavity substantially forms the active area of the base.

17. A system as in claim 16, further comprising a substantially j-shaped substrate, wherein the reflective surfaces of the cavity, the wall and the mask comprise a diffusely reflective coating on appropriate sections of the j-shaped substrate.

18. A system as in claim 17, wherein the reflective surface of the shoulder comprises a polished section of the substrate adjacent the cavity, and a reflective surface of the second wall comprises a polished section of the substrate adjacent an edge of the mask.

19. A system as in claim 1, wherein the electromagnetic transducer comprises an elongated tubular lamp positioned between the mask and the base.

20. A system as in claim 1, wherein the electromagnetic transducer comprises:

a light source positioned remote from the base and the mask;

one or more optical fibers having proximal ends coupled the light source; and

one or more openings through either the base or the mask coupled to distal ends of the one or more optical fibers, to supply light from the source to a region between the base and the mask.

21. A system as in claim 1, further comprising a baffle, having a highly diffusely reflective characteristic with respect to the radiant energy, located between the base and the mask, for increasing intensity of radiant energy distributed toward peripheral portions of the region to be illuminated.

22. A system as in claim 21, wherein the baffle comprises a cone extending from a broad end to a narrow end, and the broad end of cone is located within the cavity.

23. A system as in claim 22, wherein an annular surface of the baffle extends to the inner wall of the cavity.

24. A system as in claim 17, further comprising a retro-reflector located along an axis of the base and the mask substantially opposite the active area of the base and at a distance from the mask, a retro-reflective surface of the retro-reflector facing substantially toward the base and the mask.

25. A system as in claim 24, further comprising a pair of walls, extending from the shoulder to the retro-reflector, located on opposite sides of the base and mask, wherein opposing surfaces of the pair of walls have a reflective characteristic.

26. A radiant energy transducing system, comprising:

a substrate having a substantially j-shaped cross-section forming a base, a mask and a connecting wall between the base and the mask;

a reflective surface formed on the base, a portion of the reflective surface on the base constituting an active optical area of the base and another portion of the reflective surface on the base constituting a shoulder adjacent the active optical area;

a cavity formed in the mask having an aperture facing substantially toward the active optical area of the base

a reflective surface formed on the interior of the cavity;

a reflective surface formed on the connecting wall; and

an electromagnetic transducer for transducing between radiant energy associated with a region between the active optical area and the mask and corresponding electrical signals,

wherein the mask has a size in relation to the active optical area and is spaced a distance from the active optical area such that the system exhibits a predetermined performance characteristic with respect to the radiant energy over a predetermined field of operation.

27. A system as in claim 26, wherein each of the reflective surfaces exhibits a substantially diffuse reflectivity.

28. A system as in claim 27, wherein the reflective surfaces comprise a substantially continuous reflective coating formed on appropriate regions of the substrate.

29. A system as in claim 26, wherein the substrate further comprises another wall adjacent a periphery of the aperture at a distance from the connecting wall and extending in a direction substantially away from the base, and the system further comprises a reflective surface formed on the other wall.

30. A system as in claim 29, wherein each of the reflective surfaces exhibits a substantially diffuse reflectivity.

31. A system as in claim 30, wherein the reflective surfaces comprise a substantially continuous reflective coating formed on appropriate regions of the substrate.

32. A system as in claim 31, wherein the cavity and the connecting wall consist of a continuous curved section of the j-shaped substrate extending from the active area of the base to a peripheral region of the mask.

33. A system as in claim 26, wherein the electromagnetic transducer comprises a light source.

34. A system as in claim 26, wherein the cavity comprises a segment of a cylinder.

35. A system as in claim 34, wherein the aperture is a substantially elongated rectangle, and the electromagnetic transducer comprises an elongated tubular member located between the active area of base and the reflective surface of the cavity.

39. A system as in claim 29, wherein the reflective surface on the shoulder and the reflective surface of the other wall have substantially specular reflective characteristics.

36. A radiant energy transducing system, comprising:

a substrate having a substantially j-shaped cross-section forming a base, a mask and a connecting wall between the base and the mask;

a cavity formed in the base having an aperture facing substantially toward the mask;

a reflective surface formed on an interior surface the cavity;

a reflective surface formed on a surface of the mask facing substantially toward the aperture;

a reflective surface formed on the connecting wall;

a reflective surface formed on the shoulder; and

an electromagnetic transducer for transducing between radiant energy in a region between the mask and the cavity and corresponding electrical signals;

wherein the mask has a size in relation to the active optical area and is spaced a distance from the aperture such that the system exhibits a predetermined performance characteristic with respect to the radiant energy over a predetermined field of operation.

37. A system as in claim 36, wherein each of the reflective surfaces formed on the mask, the wall and the cavity comprise a coating having a substantially diffuse reflectivity with respect to the radiant energy.

38. A system as in claim 36, wherein the substrate further comprises another wall adjacent a periphery of the mask at a distance from the connecting wall and extending in a direction substantially away from the base, and the system further comprises a reflective surface formed on the other wall.

40. A system as in claim 36, wherein the substrate comprises:

a first section including the mask, the other wall and a first curved section of the connecting wall; and

a second section including the base, the cavity, the shoulder and a first curved section of the connecting wall,

wherein the first and second sections of the substrate are arranged such that the first curved section of the connecting wall abuts the second curved section of the connecting wall.

41. A system as in claim 36, wherein the electromagnetic transducer comprises a light source.

42. A system as in claim 41, wherein the cavity comprises a segment of a cylinder, and the aperture is a substantially elongated rectangle.

43. A system as in claim 42, wherein, and the light source comprises:

a lamp separate from the base and mask;

one or more optical fibers coupled at a proximal end to the lamp; and

one or more openings through the mask coupled to a distal end of the one or more optical, to supply light from the source toward the cavity.