SIDE-EMITTING OPTICAL COUPLING DEVICE

• US 20130342096A1
• Filed: 08/27/2013
• Published: 12/26/2013
• Est. Priority Date: 10/12/2004
• Status: Active Grant

• Current Assignee: Creeled Incorporated
• Original Assignee: CREE Incorporated (Wolfspeed, Inc.)
• Inventors: KELLER, BERND, JACOBSON, BENJAMIN, GENGELBACH, ROBERT
• Granted Patent: US 9,287,474 B2
• Time in Patent Office: Days
• US Class Current: 313/111
• CPC Class Codes: F21K 9/60 Optical arrangements integrated in the light source, e.g. for improving the colour rendering index or the light extraction
• CPC Class Codes: F21K 9/61 using light guides
• 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 19/0071 adapted to illuminate a complete hemisphere or a plane extending 360 degrees around the source
• CPC Class Codes: G02B 6/4214 the intermediate optical element having redirecting reflective means, e.g. mirrors, prisms for deflecting the radiation from horizontal to down- or upward direction toward a device G02B6/4246 takes precedence
• CPC Class Codes: H01L 33/483 Containers
• CPC Class Codes: H01L 33/52 Encapsulations
• CPC Class Codes: H01L 33/54 having a particular shape
• CPC Class Codes: H01L 33/58 Optical field-shaping elements
• CPC Class Codes: H01L 33/60 Reflective elements

Abstract

An LED package includes a LED structure that outputs light in a pattern about an axis and an optical coupling device with a central axis. The coupling device is positioned relative to the LED structure and accepts light from the LED. The coupling device includes a first dielectric interface surface that is substantially cylindrical with respect to the central axis, and a reflecting surface. The first dielectric interface surface accepts a first portion of light from the LED structure and directs it toward the reflecting surface. The reflecting surface accepts the light from the first dielectric interface surface and directs it toward the first dielectric interface surface in a direction substantially perpendicular to the central axis.

Claims

1. A light emitting diode (LED) package comprising:

an LED structure outputting light in a pattern about an axis; and

an optical coupling device having a central axis and positioned relative to the LED structure to accept light from the LED, the device comprising a homogenous first dielectric interface surface that is substantially cylindrical with respect to the central axis, and a substantially conical reflecting surface, the first dielectric interface surface accepting a first portion of light from the LED structure and directing it toward the reflecting surface, the reflecting surface accepting the light from the first dielectric interface surface and directing it toward the first dielectric interface surface to exit the device in a direction substantially perpendicular to the central axis.

2. The package of claim 1, wherein the reflecting surface is configured to accept substantially all of said first portion of light from the first dielectric interface surface and direct it toward the first dielectric interface surface such that the light can exit the device in a direction substantially perpendicular to the central axis.

3. The package of claim 1, wherein said reflecting surface is configured to receive a second portion of light and reflect said second portion toward said first dielectric interface surface.

4. The package of claim 1, wherein said reflecting surface comprises an inner portion and an outer portion.

5. The package of claim 4, wherein said inner portion is configured to accept a second portion of light from said emitter structure and direct it toward said first dielectric interface surface such that the light exits the device in a direction substantially perpendicular to the central axis.

6. The package of claim 5, wherein said inner portion is configured to receive at least some light directly from said emitter structure.

7. The package of claim 5, wherein said inner portion is configured to receive light emitted from said emitter structure within about 20°

of said central axis.

8. The package of claim 4, wherein said outer portion is configured to receive light from said first dielectric interface surface.

9. The package of claim 4, wherein said first dielectric interface surface is configured to receive light emitted by said emitter structure between about 20°

and about 50°

from said central axis.

10. The package of claim 4, wherein said inner portion is flatter than said outer portion.

11. The package of claim 4, wherein one or both of said inner and outer portions are concave.

12. The package of claim 4, wherein one or both of said inner and outer portions are convex.

13. The package of claim 1, further comprising a second dielectric interface surface configured to accept a second portion of light from the emitter structure and refract said light such that it exits the package in a direction substantially perpendicular to said central axis.

14. The package of claim 13, wherein said second portion of light is emitted from said emitter structure at angles of about 50°

and wider.

15. The package of claim 13, wherein said second dielectric interface surface is generally convex.

16. A light emitting system comprising one or more light guides and a package according to claim 1;

wherein said package is disposed proximate to said one or more light guides; and

wherein said one or more light guides are configured to accept at least a portion of light emitted from said package.

17. The light emitting system of claim 16, wherein said one or more light guides at least partially surrounds said package.

18. The light emitting system of claim 17, comprising a disk-shaped light guide.

19. The light emitting system of claim 16, wherein said package is configured to emit light in a full circle of directions substantially coplanar with said light guide.

20. A light emitting package comprising:

a base structure;

an emitter mounted on said base structure; and

an optical coupling device having a central axis and positioned relative to said emitter to accept light from said emitter, the device comprising;

a first dielectric interface surface having sidewalls substantially perpendicular to said base structure; and

a reflecting surface comprising a first portion within said first dielectric interface surface and a second portion outside said first dielectric interface surface;

wherein the reflecting surface is configured to reflect light in a direction substantially perpendicular to said central axis.

21. The package of claim 20, wherein said first portion is steeper than said second portion.

22. The package of claim 20, wherein said first portion comprises a lower section and an upper section.

23. The package of claim 22, wherein said lower section is steeper than said upper section.

24. The package of claim 20, wherein said second portion is angled 30°

or less from perpendicular to said central axis.

25. The package of claim 20, wherein said second portion is configured to receive light refracted by said first dielectric interface surface.

26. The package of claim 20, wherein said reflecting surface is substantially conical.

27. The package of claim 20, wherein said base structure comprises a perimeter support surrounding said emitter.

28. A light emitting system comprising:

one or more emitters;

at least one reflector proximate to said emitters;

at least one light guide;

wherein said light guide is configured to accept at least a portion of light from said emitters.

29. The light emitting system of claim 28, wherein said reflector is configured to reflect light from said emitters in a pattern substantially coplanar with said light guide;

and

wherein said light guide is configured to accept said reflected light.

30. The light emitting system of claim 28, wherein said reflector is configured to reflect light in a radial pattern.

31. The light emitting system of claim 30, wherein said light guide comprises a first surface substantially parallel to a primary emission axis of said emitters;

and

wherein said first surface is configured to accept at least about 180 degrees of said radially reflected light.

32. The light emitting system of claim 31, wherein said first surface is configured to accept substantially all of said radially reflected light.

33. The light emitting system of claim 28, wherein said reflector is configured to reflect light in a full circle of directions substantially coplanar with said light guide.

34. The light emitting system of claim 28, wherein said at least one light guide at least partially surrounds said emitters.

35. The light emitting system of claim 28, wherein said emitters are disposed in the center of said light guide.

36. The light emitting system of claim 28, wherein said light guide is disk-shaped.

37. The light emitting system of claim 28, comprising first and second light guides;

wherein said reflector is configured to reflect a first portion of light from said emitters in a radial pattern substantially coplanar with said first and second light guides; and

wherein each of said first and second light guides is configured to accept about half of said first portion of light.

38. The light emitting system of claim 28, wherein an emitter package comprises said reflector and at least one of said emitters, said emitter package configured to emit light in a direction substantially perpendicular to a primary emission axis of said emitters.

39. The light emitting system of claim 28, wherein said portion of light is refracted and reflected throughout said light guide.

40. The light emitting system of claim 28, wherein said portion of light propagates within said light guide via total internal reflection.

41. A light emitting system, comprising:

an emitter package comprising an emitter, said emitter emitting light about a primary emission axis; and

a light guide at least partially surrounding said emitter package;

wherein said light guide is configured to accept at least a portion of the light emitted by said emitter package.

42. The light emitting system of claim 41, wherein said emitter package emits light in a direction substantially perpendicular to said primary emission axis.

43. The light emitting system of claim 41, wherein said light guide comprises a first surface approximately parallel to said primary chip emission axis;

wherein said first surface is configured to accept light emitted from said emitter package.

44. The light emitting system of claim 43, wherein said first surface is configured to accept substantially all light emitted from said emitter package.

45. The light emitting system of claim 41, wherein said light guide substantially fully surrounds said emitter package.

46. The light emitting system of claim 41, wherein said light guide is substantially disk-shaped.

47. The light emitting system of claim 41, wherein said light guide is substantially planar.

48. The light emitting system of claim 41, wherein said light guide comprises a tapering surface.

49. The light emitting system of claim 41, wherein said light guide comprises a concave or convex surface.

50. The light emitting system of claim 41, wherein said light guide is panel shaped.

51. The light emitting system of claim 41, wherein said light guide comprises a curved surface.

52. The light emitting system of claim 41, wherein an emission surface of said light guide comprises surface roughness.

53. The light emitting system of claim 41, wherein said light guide comprises a sawtooth refractive portion.

54. The light emitting system of claim 41, wherein said light guide comprises a lens.

55. The light emitting system of claim 41, wherein said light guide comprises a Fresnel lens.

56. The light emitting system of claim 41, wherein said portion of light is refracted and reflected throughout the entire light guide.

57. The light emitting system of claim 41, wherein said portion of light propagates within said light guide via total internal reflection.