Method and apparatus for the efficient collection and distribution of light for illumination

• US 20040155565A1
• Filed: 02/06/2003
• Published: 08/12/2004
• Est. Priority Date: 02/06/2003
• Status: Abandoned Application

• Current Assignee: CAD Research Incorporated
• Original Assignee: CAD Research Incorporated
• Inventors: Holder, Ronald G., Rhoads, Greg
• Application Number:
  US10/361,137
• Publication Number:
  US 20040155565A1
• Time in Patent Office: Days
• US Class Current: 313/113
• CPC Class Codes: A61B 1/0669 at proximal end of an endoscope
• CPC Class Codes: A61B 1/0684 using light emitting diodes [LED]
• CPC Class Codes: A61B 1/07 using light-conductive means, e.g. optical fibres
• CPC Class Codes: F21S 43/14 Light emitting diodes [LED]
• CPC Class Codes: F21V 7/0008 providing for indirect lighting
• CPC Class Codes: H01L 33/54 having a particular shape
• CPC Class Codes: H01L 33/60 Reflective elements

Abstract

The emitter within LED lamp(s) radiates light over of solid angle of approximately 2π steradians or an approximate hemisphere. Conventionally, some of the light emitted is directly transmitted to the object to be illuminated and another portion is indirectly transmitted by means of a reflector, refractive optic or both. The disclosed method increases the collection efficiency of the radiated energy from LED lamp(s) by turning the LED or other light source so that all of its transmitted light is directed away from the object of the apparatus and directed into a reflector. The reflector then reflects the light toward the object. This singular handling of all the energy from the emitter results in more precise control of the radiated energy of the source. Optional subsequent controlling elements may be utilized efficiently due to the fact that the rays they will affect are of a single class of rays.

Claims

1. An apparatus comprising:

a source of light emitting light rays with a defined forward direction which is substantially the direction of the center of all rays emanating from the source; and

a light reflector with a defined optical axis and a defined forward direction;

wherein the source of light is oriented toward the reflector so that the light reflected by the reflector is propagated substantially opposite the forward direction of the source and along the forward direction of the reflector.

2. The apparatus of claim 1 where the source of light has a base through which little light is propagated with light generally propagating away from the source in directions not directed into the base of the source, and wherein the base of the source is directed away from the reflector.

3. The apparatus of claim 1 where the reflector collects substantially all of the light and directs it toward a predetermined direction of illumination.

4. The apparatus of claim 3 where the reflector tends to collimate the collected light and direct it toward the predetermined direction of illumination.

5. The apparatus of claim 1 where the source of light is a light emitting diode.

6. The apparatus of claim 5 where the light emitting diode is packaged in a transparent body shaped to provide a lens disposed proximate to the light emitting diode for focusing light from the light emitting diode in a defined direction, and where the light emitting diode is oriented so that the defined direction is turned back into the reflector which collects substantially all of the light emitted from the light emitting diode and directs the collected light in a predetermined direction generally opposite to the defined direction of the light emitting diode.

7. The apparatus of claim 6 where there is space defined between the body of the light emitting diode and the reflector and where the transparent body of the light emitting diode is potted in a transparent material with an at least approximately matching index of refraction filling the space between the light emitting diode and the reflector.

8. The apparatus of claim 5 where the light emitting diode is characterized by a substantially two dimensional area acting as the source of light defined as a light surface, light being emitted from the light surface from only one side of the light surface, the light emitting diode be oriented so that the light surface is directed back into the reflector, the reflector collecting substantially all of the light from the light surface and directing it in at least one predetermined direction.

9. The apparatus of claim 8 further comprising a mechanical fixture attached to the light emitting diode for orienting the source of light with respect to the reflector.

10. The apparatus of claim 8 further comprising a transparent material disposed between the reflector and the light emitting diode for orienting the source of light with respect to the reflector.

11. The apparatus of claim 10 where there is a defined space between the reflector and the light surface of the light emitting diode, and where the transparent material disposed between the reflector and the light emitting diode completely fills the space between the light surface and the reflector.

12. The apparatus of claim 11 where the transparent material has a defined surface and where the reflector is a specular layer on the defined surface to comprise the reflector.

13. The apparatus of claim 1 where the source of light comprises an incandescent light source.

14. The apparatus of claim 1 where the source of light comprises a plasma light source.

15. The apparatus of claim 1 where the source of light comprises a fluorescent light source.

16. A method comprising:

providing light from a source in at least one direction of preferred light propagation defined as a solid light angle while not providing any substantial amount of light in at least one other direction defined as a solid shadow angle;

directing light in the solid light angle to a reflector to be entirely collected;

redirecting substantially all of the collected light from the reflector into at least one predetermined direction; and

directing the solid shadow angle in a direction other than to the reflector so that the reflector collects substantially all of the light emitted by the source.

17. The method of claim 16 where the source of light has a base through which little light is propagated with light generally propagating away from the source in directions not directed into the base of the source, and wherein the base of the source is directed away from the reflector, so that the base defines the solid shadow angle, where directing the solid shadow angle in a direction other than to the reflector comprises orienting the base away from the reflector.

18. The method of claim 16 further comprising collimating the collected light and directing it toward the predetermined direction.

19. The method of claim 16 where providing light from a source comprises providing light from a light emitting diode.

20. The method of claim 16 where there is space defined between the body of the light emitting diode and the reflector and where directing light in the solid light angle to a reflector to be entirely collected comprises potting the transparent body of the light emitting diode in a transparent material with an approximately matching index of refraction filling the space between the light emitting diode and the reflector.

21. The method of claim 16 where the light emitting diode is characterized by a two dimensional area acting as the source of light defined as a light surface, light being emitted from the light surface substantially from only one side of the light surface, where directing light in the solid light angle to a reflector comprises orienting the light emitting diode so that the light surface is directed back into the reflector, the reflector extending to collect substantially all of the light from the light surface.

22. The method of claim 21 where orienting the light emitting diode with respect to the reflector comprises attaching a mechanical fixture to the light emitting diode to fix the orientation back toward the reflector.

23. The method of claim 21 where orienting the light emitting diode with respect to the reflector comprises disposing a transparent material between the reflector and the light emitting diode in which material the light emitting diode is fixed in an orientation directed back to the reflector.

24. The method of claim 23 further comprising providing the transparent material with a defined surface and providing the reflector by disposing a specular layer on the defined surface.

25. The method of claim 16 where providing light from a source comprises providing an incandescent light source.

26. The method of claim 16 where providing light from a source comprises providing a plasma light source.

27. The method of claim 16 where providing light from a source comprises providing a fluorescent light source.

28. A method for illuminating an object in combination with a light collecting reflector comprising:

providing a light source; and

orienting and positioning the light source relative to the reflector to direct to the light toward the collecting reflector which reflects substantially all of the light toward the object.

29. The method of claim 28 further comprising providing the light collecting reflector.

30. The method of claim 28 where the light source also has a substantially unilluminated solid angle into which substantially no light is emitted, and where orienting the light source directs the substantially unilluminated solid angle toward the object to be illuminated.

31. The method of claim 29 further comprising collimating the light and directing it toward the object to be illuminated.

32. The method of claim 29 where there is a defined space between the reflector and the light surface of the light emitting diode, and where orienting and positioning the light source relative to the reflector comprises disposing a transparent material between the reflector and the light emitting diode completely fills the space between the light surface and the reflector.

33. An apparatus comprising:

an LED emitter with emitted ray pattern substantially directed into a hemispherical angle space, the pattern having a defined forward direction; and

a reflective surface facing the forward direction of the LED emitter, which reflective surface reflects the energy from the emitter back in an approximately opposite direction to the LED emitter'"'"'s forward direction.

34. The apparatus of claim 33 where the reflective surface comprises a surface of revolution with conic or aconic cross-section.

35. The apparatus of claim 33 where the reflective surface comprises a surface, which shapes the reflecting energy via nonanalytically defined points, such as facets or nonuniform cross sections.

36. The apparatus of claim 33 where the reflective surface comprises a surface which is either uniformly or randomly disturbed to provide integration of the energy.

37. The apparatus of claim 33 further comprising an optical surface and where the energy reflected from the reflective surface is, after being reflected, refracted through the optical surface.

38. The apparatus of claim 37 where the optical surface comprises a conical, spherical, aconic, or Fresnel optical surface.

39. The apparatus of claim 33 where the LED emitter is provided as a premanufactured LED package with a lens portion and where the reflector surface is provided as a separate reflector.

40. The apparatus of claim 33 where the LED emitter has a center and further comprises a premanufactured LED package with a lens portion, which has been modified by machining a spherical surface on the lens portion with a spherical center approximately at the center of the LED emitter.

41. The apparatus of claim 33 where the reflective surface comprises a reflector body on which a specular surface is provided and where the LED emitter further comprises a premanufactured LED package which has been immersed in an index matching, or near index matching material by either molding around it the premanufactured LED package filling a space between the reflector body and premanufactured LED package, or by potting it into a premolded recess defined in a reflector body for receiving the premanufactured LED package.

42. The apparatus of claim 37 where the LED emitter, reflective surface and optical surface are each separate from each other, and are glued, potted, bonded, molded or assembled into a single unit.

43. The apparatus of claim 33 further comprising an optic fiber, the reflective surface being focused on the optic fiber so that the numerical aperture of the optic fiber and reflective surface are matched.

44. The apparatus of claim 43 where the optic fiber has an end surface and where the LED emitter, reflective surface and end surface of the optic fiber are integrated into a single body.

45. The apparatus of claim 43 further comprising a detector so that the apparatus is an optical transceiver.