CONDENSING ELEMENT, ARRAY, AND METHODS THEREOF

• US 20100097809A1
• Filed: 10/20/2008
• Published: 04/22/2010
• Est. Priority Date: 10/20/2008
• Status: Active Grant

• Current Assignee: Orafol Americas Inc. (Orafol Europe GmbH)
• Original Assignee: Reflexite
• Inventors: Munro, Penny J., Munro, James F.
• Granted Patent: US 8,235,556 B2
• Time in Patent Office: Days
• US Class Current: 362/308
• CPC Class Codes: F21V 5/002 using microoptical elements for redirecting or diffusing light
• CPC Class Codes: F21V 5/045 the lens having discontinuous faces, e.g. Fresnel lenses
• CPC Class Codes: F21V 7/0091 using total internal reflection
• CPC Class Codes: F21Y 2103/10 comprising a linear array of point-like light-generating elements
• CPC Class Codes: F21Y 2115/10 Light-emitting diodes [LED]
• CPC Class Codes: G02B 19/0028 refractive and reflective surfaces, e.g. non-imaging catadioptric systems
• CPC Class Codes: G02B 19/0066 in the form of an LED array

Abstract

A condensing element, array, and methods thereof include a bowl-shaped outer section and a lens-shaped inner section. The outer section provides substantially total internal reflection of light entering at an input surface of the outer section. The inner section is recessed within the outer section at a distance from the entering light that is within the focal position of the inner section. The outer and inner sections are configured in a preferred embodiment so that substantially all the light exiting the condensing element is substantially parallel to the optical axis of the entering light. In an alternate embodiment, the configuration of the condensing element can be modified to selectively adjust the desired degree of collimation of the exiting light.

Claims

1. A condensing element comprising:

a bowl-shaped outer section having a sidewall between a light input surface at one end and a light output surface at the other end and providing substantially total internal reflection of light emitted from the input surface and incident upon the sidewall of the outer section; and

a lens-shaped inner section that is recessed within the outer section and having a sidewall extending to the output surface of the outer section;

wherein light emitted from the light input surface is not directly incident upon the output surface.

2. The element as set forth in claim 1, wherein light emitted from the input surface and passing through the inner section is not incident on the output surface.

3. The element as set forth in claim 1, further comprising a light source in optical communication with the input surface.

4. The element as set forth in claim 1, wherein the light input surface comprises a planar base of the outer section.

5. The element as set forth in claim 4, wherein the planar input surface comprises a recess sufficient to accommodate an adhesive.

6. The element as set forth in claim 4, wherein the light input surface comprises a protuberance.

7. The element as set forth in claim 3, further comprising a film installed between the light source and the input surface.

8. The element as set forth in claim 1, wherein the inner section comprises a lens.

9. The element as set forth in claim 1, wherein the inner section comprises a Fresnel lens.

10. The element as set forth in claim 1, wherein the inner section comprises a TIRing Fresnel lens.

11. The element as set forth in claim 1, wherein the inner section comprises a conical shape.

12. The element as set forth in claim 1, wherein the inner section comprises a truncated cone.

13. The element as set forth in claim 12, wherein the truncated cone has a lens-shaped top.

14. The element as set forth in claim 1, wherein the inner section exhibits total internal reflection.

15. The element as set forth in claim 1, wherein the inner section comprises a peak that extends above the output surface.

16. The element as set forth in claim 1, wherein the inner section comprises a peak that is at the level of the output surface.

17. The element as set forth in claim 1, wherein the inner section comprises a peak that is below the output surface.

18. The element as set forth in claim 1, wherein the inner section comprises a prescription such that the half-power angle of the light exiting from the lens is less than about twenty degrees about the optical axis of the input light.

19. The element as set forth in claim 1, wherein the inner section comprises a prescription such that the half-power angle of the light exiting from the output surface is less than or equal to about twenty degrees about the optical axis of the input light.

20. The element as set forth in claim 1, wherein the light output surface is planar.

21. The element as set forth in claim 1, wherein the light output surface is textured.

22. The element as set forth in claim 1, wherein the light output surface is micro-structured.

23. The element as set forth in claim 1, wherein the light output surface comprises a diffractive optical element.

24. The element as set forth in claim 1, wherein the light output surface is curved.

25. The element as set forth in claim 1, wherein the outer section sidewall has a prescription such that the totally internally reflected light is reflected in a direction that is substantially parallel to the optical axis of the input light.

26. The element as set forth in claim 1, wherein the outer section and the inner section of the condensing element are integrally formed together.

27. The element as set forth in claim 1, further comprising a layer of material provided below the output surface which facilitates molding of the element.

28. The element as set forth in claim 1, further comprising multiple condensing elements arranged in an array.

29. The element as set forth in claim 28, wherein the array is planar.

30. The element as set forth in claim 28, wherein the configuration of the array is adjustable.

31. The element as set forth in claim 28, wherein the array is attached to a light output surface of a light-guide.

32. A method for making a condensing element, the method comprising:

forming a bowl-shaped outer section having a sidewall between a light input surface at one end and a light output surface at the other end and providing substantially total internal reflection of light emitted from the input surface and incident upon the sidewall of the outer section and;

recessing within the outer section, a lens-shaped inner section having a sidewall extending to the output surface of the outer section, at a distance from the entering light that is within the focal position of the inner section, such that light emitted from the input surface is not directly incident upon the output surface.

33. The method as set forth in claim 32, further comprising providing a light source in optical communication with the input surface.

34. The method as set forth in claim 32, wherein the light input surface comprises a planar base of the outer section.

35. The method as set forth in claim 34, wherein the planar input surface comprises a recess sufficient to accommodate an adhesive.

36. The method as set forth in claim 34, wherein the light input surface comprises a protuberance.

37. The method as set forth in claim 33, further comprising installing a film between the light source and the input surface.

38. The method as set forth in claim 32, wherein the inner section comprises a lens.

39. The method as set forth in claim 32, wherein the inner section comprises a Fresnel lens.

40. The method as set forth in claim 32, wherein the inner section comprises a TIRing Fresnel lens.

41. The method as set forth in claim 32, wherein the inner section comprises a conical shape.

42. The method as set forth in claim 32, wherein the inner section comprises a truncated cone.

43. The method as set forth in claim 42, wherein the truncated cone has a lens-shaped top.

44. The method as set forth in claim 32, wherein the inner section exhibits total internal reflection.

45. The method as set forth in claim 32, wherein the inner section comprises a peak that extends above the output surface.

46. The method as set forth in claim 32, wherein the inner section comprises a peak that is at the level of the output surface.

47. The method as set forth in claim 32, wherein the inner section comprises a peak that is below the output surface.

48. The method as set forth in claim 32, wherein the inner section comprises a prescription such that the half-power angle of the light exiting from the lens is less than about twenty degrees about the optical axis of the input light.

49. The method as set forth in claim 32, wherein the inner section comprises a prescription such that the half-power angle of the light exiting from the output surface is less than or equal to about twenty degrees about the optical axis of the input light.

50. The method as set forth in claim 32, wherein the light output surface is planar.

51. The method as set forth in claim 32, wherein the light output surface is textured.

52. The method as set forth in claim 32, wherein the light output surface is micro-structured.

53. The method as set forth in claim 32, wherein the light output surface comprises a diffractive optical element.

54. The method as set forth in claim 32, wherein the light output surface is curved.

55. The method as set forth in claim 32, wherein the outer section sidewall has a prescription such that the totally internally reflected light is reflected in a direction that is substantially parallel to the optical axis of the input light.

56. The method as set forth in claim 32, further comprising integrally forming together the outer section and the inner section of the condensing element.

57. The method as set forth in claim 32, further comprising providing a layer of material below the output surface which facilitates molding of the element.

58. The method as set forth in claim 32, further comprising arranging multiple condensing elements in an array.

59. The method as set forth in claim 58, wherein the array is planar.

60. The method as set forth in claim 58, wherein the configuration of the array is adjustable.

61. The method as set forth in claim 58, further comprising attaching the array to a light output surface of a light-guide.

62. The method as set forth in claim 32, wherein light emitted from the input surface and passing through the inner section is not incident on the output surface.