Tiring condensing element and methods thereof

• US 20100079987A1
• Filed: 09/30/2008
• Published: 04/01/2010
• Est. Priority Date: 09/30/2008
• Status: Active Grant

• Current Assignee: Orafol Americas Inc. (Orafol Europe GmbH)
• Original Assignee: Reflexite
• Inventors: Munro, Penny J., Munro, James F.
• Granted Patent: US 8,226,262 B2
• Time in Patent Office: Days
• US Class Current: 362/231
• CPC Class Codes: F21K 9/00 Light sources using semiconductor devices as light-generating elements, e.g. using light-emitting diodes [LED] or lasers
• CPC Class Codes: F21L 4/005 the device being a pocket lamp F21L4/022, F21L4/045, F21L4/085 take precedence
• CPC Class Codes: F21S 41/143 the main emission direction of the LED being parallel to the optical axis of the illuminating device
• CPC Class Codes: F21S 41/322 the reflector using total internal reflection
• CPC Class Codes: F21V 5/04 of lens shape
• CPC Class Codes: F21V 7/0091 using total internal reflection
• 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 19/0061 the light source comprising a LED semiconductor devices with at least one potential-jump barrier or surface barrier specially adapted for light emission H01L33/00
• CPC Class Codes: G02B 19/0066 in the form of an LED array

Abstract

A TIRing condensing element and methods thereof includes a first section and a second section. The first section provides substantially total internal reflection of light entering at a base of the first section. The second section tapers from a first section towards an optical axis of the element extending through the second section to output light from the first section. The first and second sections are configured so a half-power angle of the light output from the second section is less than the half-power angle of the light entering the first section.

Claims

1. A condensing element comprising:

a first section that provides substantially total internal reflection of light entering at a base of the first section; and

a second section which tapers from a first section towards an optical axis of the element extending through the second section to output light from the first section, the first and second sections are configured so a half-power angle of the light output from the second section is less than the half-power angle of the light entering the first section.

2. The element as set forth in claim 1 wherein the first section has at least one sidewall with a curvature to provide the substantially total internal reflection of light entering at the base of the first section.

3. The element as set forth in claim 1 wherein the second section has at least one sidewall which is substantially linear in cross-section and provides internal reflection and refraction of the light from the first section.

4. The element as set forth in claim 3 wherein the at least one sidewall of the second section tapers to an end point at the optical axis for the condensing element.

5. The element as set forth in claim 1 wherein the second section has at least one sidewall that is at least one of non-linear in cross-section, textured, and made from a light diffusing material.

6. The element as set forth in claim 1 wherein the half-power angle of the light output from the second section is less than or equal to about twenty degrees about the optical axis.

7. The element as set forth in claim 6 wherein the half-power angle of the light entering the first section is greater than or equal to about forty degrees about the optical axis.

8. The element as set forth in claim 1 wherein a base of the first section is substantially piano.

9. The element as set forth in claim 1 further comprising at least one light source positioned to transmit light into the first section of the condensing element.

10. The element as set forth in claim 9 further comprising at least one transparent layer between the at least one light source and the condensing element, wherein the condensing element increases an extraction efficiency of the transmitted light passing through the at least one transparent layer from the at least one light source.

11. The element as set forth in claim 9 wherein the light source is at least one light emitting diode.

12. The element as set forth in claim 9 further comprising multiple light sources positioned adjacent the optical axis to transmit light into the first section of the condensing element.

13. The element as set forth in claim 12 wherein the multiple light sources comprise a red light source, a green light source, and a blue light source.

14. The element as set forth in claim 1 wherein the first section and the second section of the condensing element are integrally formed together.

15. The element as set forth in claim 1 wherein the base comprises a plurality of separate base sections provided about the optical axis, each of the base sections integrally formed with the second section and including a respective first section providing substantially total internal reflection of light entering at a respective base section.

16. The element as set forth in claim 15 wherein a light source is provided at each the base section to transmit light into the respective first section of the condensing element.

17. The element as set forth in claim 16 wherein the light sources are light emitting diodes.

18. The element as set forth in claim 15 wherein the number of base sections is greater than or equal to two.

19. The element of claim 1 wherein condensed light output from the second section is white.

20. A method for making a condensing element the method comprising:

forming a first section that provides substantially total internal reflection of light entering at a base of the first section; and

forming a second section which tapers from the first section towards an optical axis extending through the second section to output light from the first section, the first and second sections are formed so a half-power angle of the light output from the second section is less than the half-power angle of the light entering the first section.

21. The method as set forth in claim 20 further comprising forming the first section to have at least one sidewall with a curvature to provide the substantially total internal reflection of light entering at the base of the first section.

22. The method as set forth in claim 20 further comprising forming the second section to have at least one sidewall which is substantially linear in cross-section and provides internal reflection and refraction of light from the first section.

23. The method as set forth in claim 22 wherein the forming the second section further comprises forming the at least one sidewall of the second section to taper to an end point at the optical axis of the condensing element.

24. The method as set forth in claim 20 wherein the forming the second section further comprises forming the at least one sidewall of the second section to be at least one of non-linear in cross-section, textured, and made from a light diffusing material.

25. The method as set forth in claim 20 wherein the half-power angle of the light output from the second section is less than or equal to about twenty degrees about the optical axis.

26. The method as set forth in claim 25 wherein the half-power angle of the light entering the first section is greater than or equal to forty degrees about the optical axis.

27. The method as set forth in claim 20 wherein a base of the first section for at least one of the condensing elements is formed substantially plano.

28. The method as set forth in claim 20 further comprising providing at least one light source at the base to transmit light into the first section of the condensing element.

29. The method as set forth in claim 28 further comprising providing at least one transparent layer between the at least one light source and the condensing element, wherein the condensing element increases an extraction efficiency of the transmitted light passing through the at least one transparent layer from the at least one light source.

30. The method as set forth in claim 28 wherein the light source is at least one light emitting diode.

31. The method as set forth in claim 28 further comprising providing multiple light sources at the base and adjacent the optical axis to transmit light into the first section of the condensing element.

32. The method as set forth in claim 31 wherein the multiple light sources comprise a red light source, a green light source, and a blue light source.

33. The method as set forth in claim 20 further comprising integrally forming the first section and the second section of the condensing elements together.

34. The method as set forth in claim 20 wherein forming the first section includes forming a plurality of separate base sections provided about the optical axis, each of the base sections formed integrally with the second section and including a respective the first section providing substantially total internal reflection of light entering at a respective base section.

35. The method as set forth in claim 34 further comprising providing a light source at each the separate base section to transmit light into the respective first section of the condensing element.

36. The method as set forth in claim 35 wherein the light sources are light emitting diodes.

37. The method as set forth in claim 34 wherein the number of base sections is greater than or equal to two.

38. The method of claim 20 wherein condensed light output from the second section is white.