Compact folded-optics illumination lens

• US 20040070855A1
• Filed: 10/11/2002
• Published: 04/15/2004
• Est. Priority Date: 10/11/2002
• Status: Active Grant

• Current Assignee: Light Engine Limited
• Original Assignee: Light Prescriptions Innovators LLC A Delaware Limited Liability Company
• Inventors: Benitez, Pablo, Minano, Juan C.
• Granted Patent: US 6,896,381 B2
• Time in Patent Office: Days
• US Class Current: 359/858
• CPC Class Codes: F21V 13/04 the elements being reflectors and refractors for vehicle rear lights F21S43/40
• CPC Class Codes: F21V 5/04 of lens shape
• CPC Class Codes: F21V 7/0091 using total internal reflection
• CPC Class Codes: F21Y 2101/00 Point-like light sources
• 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 27/0012 Optical design, e.g. procedures, algorithms, optimisation routines
• CPC Class Codes: G02B 3/02 with non-spherical faces G02B3/10 takes precedence

Abstract

A method for manufacturing an apparatus and the apparatus being configured to convert a first distribution of an input radiation to a second distribution of output radiation. The method consists of the steps of generating a two-dimensional representation of at least three active optical surfaces of an optical device including calculating a segment of a first surface based on edge ray sets as a first generalized Cartesian oval, calculating a segment of an entry surface based on the edge ray set as a second generalized Cartesian oval, calculating a segment of a second surface based on the edge ray set as a third generalized Cartesian oval, and successively repeating the steps of calculating the segment of the first surface and calculating the segment of the second surface in a direction towards a source, and rotationally sweeping the two-dimensional representation about a central axis providing a three-dimensional representation of the optical device.

Claims

1. A method of manufacturing an optical device, comprising the steps of:

generating a two-dimensional representation of at least three active optical surfaces of an optical device, comprising the steps of;

calculating a segment of a first surface based on edge ray sets as a first generalized Cartesian oval;

calculating a segment of an entry surface based on the edge ray set as a second generalized Cartesian oval;

calculating a segment of a second surface based on the edge ray set as a third generalized Cartesian oval; and

successively repeating the steps of calculating the segment of the first surface and calculating the segment of the second surface in a direction towards a source; and

rotationally sweeping the two-dimensional representation about a central axis providing a three-dimensional representation of the optical device.

2. The method as claimed in claim 1, wherein the step of calculating the segment of the first surface includes initially calculating a perimeter segment of the first surface;

and

wherein the step of calculating the segment of the second surface includes initially calculating a perimeter segment of the second surface.

3. The method as claimed in claim 2, wherein the step of calculating the segment of the entry surface includes initially calculating a first surface of the entry surface where a first end of the first surface of the entry surface is an inflection point along the entry surface.

4. The method as claimed in claim 2, wherein the step of calculating the segment of the entry surface includes initially calculating a first surface of the entry surface where a second end of the first surface of the entry surface is an intercept point of a near edge outer ray along the entry surface.

5. The method as claimed in claim 2, wherein the step of calculating the segment of the entry surface includes determining a position of a first end of the segment of the entry surface including the steps of:

determining a flux weighting for edge rays intercepting the first segment of the entry surface;

determining a flux weighting for all edge rays of the edge ray sets; and

determining a resultant sum of the flex weighting for the edge rays intercepting the first segment of the entry surface as a fraction of the flux weighting for all the edge-rays of the edge ray sets.

6. The method as claimed in claim 2, wherein the step of successively repeating the step of calculating the segment of the first surface includes calculating a second segment of the first surface as a fourth generalized Cartesian oval based on a far edge ray set.

7. The method as claimed in claim 6, wherein the step of calculating the second segment of the first surface includes calculating the second segment such that the far edge ray set intercepts the perimeter segment of the second surface after reflecting from the second segment of the first surface.

8. The method as claimed in claim 6, wherein the step of successively repeating the step of calculating the segment of the second surface includes calculating a second segment of the second surface as a fifth generalized Cartesian oval based on a near edge ray set.

9. The method as claimed in claim 8, wherein the step of calculating the second segment of the second surface includes calculating the second segment such that the near edge ray set intercepts the second segment of the second surface after reflecting from the second segment of the first surface.

10. The method as claimed in claim 1, wherein the step of generating a two-dimensional representation includes calculating the first, second and third surfaces such that the three-dimensional representation is configured to collimate light to an etendue limit defined by a relative size of aperture to effective source diameter.

11. The method as claimed in claim 1, wherein the step of generating a two-dimensional representation includes calculating the first, second and third surfaces such that the three-dimensional representation is configured to provide an exit beam having variable divergence angle and variable central-ray tilt such that when integrated across an exit diameter conforms to a predefined illumination prescription.

12. A method for generating an optical beam, comprising the steps of:

refracting initial light;

internally reflecting the light;

again reflecting the light; and

refracting the light producing an output light that is at least partially collimated.

13. The method as claimed in claim 12, wherein the step of internally reflecting the light includes totally internally reflecting the light.

14. The method as claimed in claim 12, wherein the output light is collimated to an etendue limit defined by a relative size of aperture to effective source diameter.

15. A folded-optics apparatus, comprising:

a transparent body including a first surface, a second surface and a cavity formed within at least the second surface;

the cavity having a third surface;

the second surface comprising a reflective region extending radially away from the cavity; and

the first surface comprising an annular zone configured to provide internal reflection folding and a refractive transition between the transparent body and an exterior of the transparent body.

16. The apparatus as claimed in claim 15, wherein the cavity is configured to be positioned about an optical device such that the third surface is proximate the optical device and the first surface emits an output optical beam.

17. The apparatus as claimed in claim 16, further comprising a gap defined between the optical device and the third surface.

18. The apparatus as claimed in claim 16, wherein the optical device is a light source, and the third surface is an entry surface allowing light emitted from the light source to pass through the third surface to enter the transparent body.

19. The apparatus as claimed in claim 15, wherein the first, second and third surfaces are optically active surfaces.

20. The apparatus as claimed in claim 19, wherein the first surface internally reflects an optical beam propagating within the body and to refract the optical beam as the beam passes through the first surface;

the second surface reflects the optical beam propagating within the body; and

the third surface refractively redistributes the optical beam as the beam passes through the third surface.

21. The apparatus as claimed in claim 15, wherein the cavity extends through the body to the first surface forming a through hole.

22. The apparatus as claimed in claim 15, wherein a beam exits the first surface and the exiting beam is collimated to an etendue limit set by a relative size of aperture to effective source-diameter.

23. The apparatus as claimed in claim 15, further comprising a light detecting device positioned at least partially within the cavity proximate the third surface of the cavity such that light received by the first surface of the transparent body passes through the third surface of the cavity to impinge on the light detecting device.

24. The apparatus as claimed in claim 15, wherein the cavity is configured to be positioned about an incandescent lamp light source such that the third surface is proximate the light source allowing light emitted from the light source to pass through the third surface to enter the transparent body.

25. The apparatus as claimed in claim 15, wherein the first surface further comprises a central region that is absorptive.

26. The apparatus as claimed in claim 25, wherein the first surface further comprises a central region that is reflective.

27. The apparatus as claimed in claim 25, wherein the first surface further comprises a central region that is refractive.

28. The apparatus as claimed in claim 15, wherein the first surface is planar.

29. The apparatus as claimed in claim 15, wherein the first surface has a reflective central cuspoid depression.

30. The apparatus as claimed in claim 15, wherein the transparent body includes a central zone, the central zone comprising an unfolded beam-forming reflector.

31. The apparatus as claimed in claim 15, wherein the transparent body is configured from a plurality of non-symmetric portions, wherein the plurality of non-symmetric portions provide bilaterally asymmetric distributions.

32. The apparatus as claimed in claim 15, wherein the first, second and third surfaces form a folded edge ray device.

33. The apparatus as claimed in claim 32, wherein the first, second and third surfaces are formed to define an RXIR device.

34. The apparatus as claimed in claim 15, wherein the cavity comprises a bell shape that compresses an angular range of a light source.

35. The apparatus as claimed in claim 15, wherein the cavity comprises a pointed arch configured such that light is deflected away from a central zone of the first surface.

36. The apparatus as claimed in claim 15, wherein the first, second and extended surfaces are configured such that an output light beam has a variable collimation across an exit diameter so as to conform to a particular illumination prescription.

37. The apparatus as claimed in claim 15, wherein the transparent body is formed of glass, silicone or injection-molded plastic.

38. The apparatus as claimed in claim 15, wherein the third surface includes an anti-reflection coating.

39. The apparatus as claimed in claim 15, wherein the transparent body includes a peripheral portion having a means for snap-fitting.

40. A method of manufacturing an optical device that convert a first distribution of an input radiation to a second distribution of output radiation, comprising:

providing a two-dimensional model that describes a first distribution of an input radiation as an input bundle of edge rays and the second distribution of an output radiation as an output bundle of edge rays, and representing the input and output edge ray bundles each in a phase-space representation in terms of the position of each ray in space;

defining a two-dimensional representation of three active optical surfaces responsive to the boundary conditions of the phase-space representations, including successively calculating segments of at least a first and second surfaces; and

symmetrically extending said two-dimensional representation of said optical surfaces to provide a three-dimensional optical device.

41. An optical device that converts a first distribution of an input radiation to a second distribution of output radiation, comprising:

first, second and third active surfaces, wherein the first and second surfaces are opposing active non-spherical optical surfaces, where the first, second and third active surfaces are defined by a two-dimensional representation that is symmetrically extended to provide a three-dimensional device; and

the first and third active surfaces provide transitions for the first and second radiation between an exterior and interior of a body of the three-dimensional device defined by the first, second and third surfaces.