LED lamp with remote phosphor and diffuser configuration

• US 9,316,361 B2
• Filed: 01/31/2011
• Issued: 04/19/2016
• Est. Priority Date: 03/03/2010
• Status: Active Grant

• Current Assignee: IDEAL Industries Lighting, LLC (Ideal Industries Incorporated)
• Original Assignee: CREE Incorporated (Wolfspeed, Inc.)
• Inventors: Tong, Tao, Le Toquin, Ronan, Keller, Bernd, Tarsa, Eric, Youmans, Mark, Lowes, Theodore, Medendorp, Nicholas W. Jr., Van De Ven, Antony, Negley, Gerald
• Primary Examiner(s): Husar, Stephen F
• Application Number:
  US13/018,245
• Publication Number:
  US 20110267800A1
• Time in Patent Office: 1,905 Days
• Field of Search: 313/501, 362/84
• US Class Current: 1/1
• CPC Class Codes: F21K 9/232 specially adapted for generating an essentially omnidirectional light distribution, e.g. with a glass bulb
• CPC Class Codes: F21K 9/64 using wavelength conversion means distinct or spaced from the light-generating element, e.g. a remote phosphor layer
• CPC Class Codes: F21V 29/505 of reflectors
• CPC Class Codes: F21V 29/767 the planes containing the fins or blades having directions perpendicular to the light emitting axis
• CPC Class Codes: F21V 29/773 the planes containing the fins or blades having the direction of the light emitting axis
• CPC Class Codes: F21V 3/02 characterised by the shape
• CPC Class Codes: F21V 3/12 the coatings comprising photoluminescent substances
• CPC Class Codes: F21Y 2115/10 Light-emitting diodes [LED]

Abstract

An LED lamp or bulb is disclosed that comprises a light source, a heat sink structure and an optical cavity. The optical cavity comprises a phosphor carrier having a conversions material and arranged over an opening to the cavity. The phosphor carrier comprises a thermally conductive transparent material and is thermally coupled to the heat sink structure. An LED based light source is mounted in the optical cavity remote to the phosphor carrier with light from the light source passing through the phosphor carrier. A diffuser dome is included that is mounted over the optical cavity, with light from the optical cavity passing through the diffuser dome. The diffuser dome can disperse the light passing through it into the desired emission pattern, such as omnidirection. In one embodiment, the light source can be blue emitting LED and the phosphor carrier can include a yellow phosphor, with the LED lamp or bulb emitting a white light combination of LED and phosphor light.

Claims

1. A lighting device comprising:

a light source;

a diffuser spaced from the light source;

a wavelength conversion material between the light source and the diffuser and spaced from the diffuser and all of said light source, the wavelength conversion material being positioned so as to receive light emitted by the light source;

wherein said wavelength conversion material comprises a phosphor carrier having a thermal conductivity of 0.5 W/m-k or more; and

heat dissipation elements between said light source and said wavelength conversion material to conduct heat away from said light source and said wavelength conversion material.

2. The lighting device of claim 1, wherein said light source is a solid state light source.

3. The lighting device of claim 1, wherein said wavelength conversion material absorbs at least some of said light emitted by said light source.

4. The lighting device of claim 1, wherein said diffuser disperses light from said light source and/or said wavelength conversion material.

5. The lighting device of claim 1, wherein said wavelength conversion material is three-dimensional.

6. The lighting device of claim 1, wherein said wavelength conversion material is planar.

7. The lighting device of claim 1, wherein said light source comprises a plurality of co-planar light emitting diodes (LEDs).

8. The lighting device of claim 1, wherein said light source comprises a plurality of non-co-planar light emitting diodes (LEDs).

9. The lighting device of claim 1, wherein said wavelength conversion material is substantially frusto-spherical.

10. The lighting device of claim 1, wherein said diffuser is substantially frusto-spherical.

11. The lighting device of claim 1, wherein said wavelength conversion material and said diffuser are substantially frusto-spherical such that said wavelength conversion material phosphor carrier and diffuser provide a double-dome structure.

12. The lighting device of claim 1, wherein the space between said light source and said wavelength conversion material and the space between said diffuser and said wavelength conversion material comprise light mixing chambers.

13. The lighting device of claim 1, wherein said diffuser at least partially conceals the appearance of said wavelength conversion material when said lighting device is not operating.

14. The lighting device of claim 13, wherein said diffuser exhibits a white appearance when said lighting device is not operating.

15. The lighting device of claim 1, providing a steady state lumen output of at least 800 lumens.

16. The lighting device of claim 1, comprising emission efficiency of greater than 50 lumens per watt.

17. The lighting device of claim 1, wherein said light source comprises 10 or fewer light emitting diodes.

18. The lighting device of claim 1, wherein said light source comprises a light emitting chip area of 10 mm² or less.

19. The lighting device of claim 1, emitting light with a color render index (CRI) greater than 80.

20. The lighting device of claim 1, configured to emit light with uniformity within 20% of a mean value from 0°

to 135° and

with greater than 5% flux from 135°

to 180°

.

21. The lighting device of claim 1, sized to fit an A19 size profile.

22. A lighting device comprising:

a solid state light source; and

a wavelength conversion material spaced from the solid state light source, the wavelength conversion material comprising a substantially frusto-spherical shape;

wherein said wavelength conversion material comprises a phosphor carrier with a thermal conductivity of 0.5 W/m-k or more, said phosphor carrier between said solid state light source and said wavelength conversion material.

23. A lighting device comprising:

a remote wavelength conversion material, said remote wavelength conversion material comprising a phosphor carrier;

a light source; and

a remote diffuser, wherein light emitted from the diffuser has reduced variation in spatial emission intensity profile over an angular range compared to the light emitted from the remote wavelength conversion material and has a peak emission outside of the viewing angle from −

20°

to 20°

, said phosphor carrier between said light source and said remote wavelength conversion material.

24. The lighting device of claim 23, wherein said light source comprises a solid state light source.

25. The lighting device of claim 23, wherein the light emitted from the diffuser has a spatial uniformity that is within 40% of a mean value within a range of viewing angles.

26. The lighting device of claim 25, wherein said range of viewing angles is 0 to 135°

.

27. The lighting device of claim 23, wherein the light emitted from the diffuser has a spatial uniformity that is within 20% of a mean value within a range of viewing angles.

28. The lighting device of claim 27, wherein said range of viewing angles is 0 to 135°

.

29. The lighting device of claim 23, wherein the light emitted from the diffuser has a color uniformity that is within a 10-step McAdams ellipse on a CIE diagram within a range of viewing angles.

30. The lighting device of claim 29, wherein the standard deviation is a 4-step MacAdams ellipse.

31. The lighting device of claim 30, wherein said range of viewing angles is 0 to 135°

.

32. The lighting device of claim 23, wherein said remote wavelength conversion material comprises a phosphor carrier comprising a thermally conductive material.

33. The lighting device of claim 32, wherein said thermally conductive material has a thermal conductivity of at least 0.5 W/m-k.

34. The lighting device of claim 23, further comprising heat dissipation elements to conduct conversion heat away from said remote wavelength conversion material.

35. The lighting device of claim 23, wherein said wavelength conversion material is three-dimensional.

36. The lighting device of claim 23, wherein said wavelength conversion material is two-dimensional.

37. The lighting device of claim 23, wherein said light source comprises a plurality of co-planar light emitting diodes (LEDs).

38. The lighting device of claim 23, wherein said light source comprises a plurality of non-co-planar light emitting diodes (LEDs).

39. The lighting device of claim 23, wherein said remote wavelength conversion material and said remote diffuser are dome-shaped such that said remote wavelength conversion material and diffuser provide a double-dome structure.

40. The lighting device of claim 23, further comprising a first space between said light source and said wavelength conversion material and a second space between said diffuser and said wavelength conversion material, wherein said spaces comprise light mixing chambers.

41. The lighting device of claim 23, wherein said diffuser at least partially conceals said wavelength conversion material when said lighting device is not operating.

42. A solid state lamp comprising:

a first solid state light emitter which defines a plane that is substantially perpendicular to the radial axis of the lamp;

an optical cavity, said first solid state light emitter within said optical cavity;

a heat sink structure, said optical cavity within said heat sink structure; and

an optical system that distributes at least 5% of the light emitted by said first solid state light emitter in a direction that is below the plane defined by the at least one solid state light emitter.

43. The solid state lamp of claim 42, wherein said at least 5% of light is emitted in viewing angles within the range of 135 to 180°

.

44. The solid state lamp of claim 42, configured to emit light with a uniformity within 20% of a mean value from 0°

to 135° and

with greater than 5% flux from 135°

to 180°

.

45. The solid state lamp of claim 42, sized to fit an A19 profile.

46. A solid state lamp, comprising:

an light emitting diode (LED) based light source;

a remote wavelength conversion material spaced from said LED light source, wherein said remote wavelength conversion material comprises a phosphor carrier having a thermal conductivity of 0.5 W/m-k or more; and

a diffuser remote to said remote wavelength conversion material wherein said diffuser comprises a shape and light scattering properties to disperse the light from said LED light source and wavelength conversion material in a substantially omnidirectional emission pattern;

said phosphor carrier between said LED based light source and said remote wavelength conversion material.

47. A solid state lamp, comprising:

a light emitting diode (LED) based light source;

a remote phosphor spaced from said LED light source, wherein said remote phosphor comprises a phosphor carrier having a thermal conductivity of 0.5 W/m-k or more; and

a diffuser remote to said remote phosphor wherein said diffuser masks said remote phosphor when said solid state lamp is not operating;

said phosphor carrier between said LED based light source and said remote phosphor.

48. The solid state lamp of claim 47, wherein said diffuser appears white when said lamp is not operating.

49. The solid state lamp of claim 47, configured to emit light with a uniformity within 20% of a mean value from 0°

to 135° and

with greater than 5% flux from 135°

to 180°

.

50. The solid state lamp of claim 47, sized to fit an A19 profile.

51. A solid state lamp, comprising:

a light emitting diode (LED) based light source;

a three dimensional remote phosphor spaced from said LED light source; and

a three dimensional diffuser remote to said remote phosphor, wherein light emitted from the diffuser has reduced variation in spatial emission intensity profile over an angular range compared to the light emitted from the remote phosphor and has a peak emission outside of the viewing angle from −

20°

to 20°

;

wherein said remote phosphor comprises a phosphor carrier, said phosphor carrier between said LED based light source and said remote phosphor.

52. A solid state lamp, comprising:

a light emitting diode (LED) based light source;

a remote phosphor comprising a frustospherical portion, said remote phosphor spaced from said LED light source; and

a diffuser comprising a frustospherical portion, said diffuser spaced from said remote phosphor;

wherein light emitted from the diffuser has reduced variation in spatial emission intensity profile over an angular range compared to the light emitted from the remote phosphor and has a peak emission outside of the viewing angle from −

20°

to 20°

;

wherein said remote phosphor comprises a phosphor carrier, said phosphor carrier between said LED based light source and said remote phosphor.

53. The solid state lamp of claim 52, configured to emit light with a uniformity within 20% of a mean value from 0°

to 135° and

with greater than 5% flux from 135°

to 180°

.

54. The solid state lamp of claim 52, sized to fit an A19 profile.