High efficiency solid state lamp and bulb

• US 9,062,830 B2
• Filed: 02/16/2011
• Issued: 06/23/2015
• 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: Le, Long Larry, Pickard, Paul, Lay, James Michael, Tong, Tao, Letoquin, Ronan, Keller, Bernd, Tarsa, Eric, Youmans, Mark, Lowes, Theodore, Medendorp, Nicholas W. Jr., Van De Ven, Antony, Negley, Gerald
• Primary Examiner(s): Roy, Sikha
• Application Number:
  US13/028,946
• Publication Number:
  US 20110215699A1
• Time in Patent Office: 1,588 Days
• Field of Search: 362/84, 362/293, 362/294, 362/311.06, 313/46
• 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 29/773 the planes containing the fins or blades having the direction of the light emitting axis
• CPC Class Codes: F21V 3/00 Globes; Bowls; Cover glasses with refracting properties F21V5/00; with reflecting properties F21V7/00; characterised by cooling arrangements F21V29/506
• CPC Class Codes: F21Y 2115/10 Light-emitting diodes [LED]
• CPC Class Codes: H01L 2224/48091 Arched
• CPC Class Codes: H01L 2224/48247 connecting the wire to a bond pad of the item
• CPC Class Codes: H01L 2224/73265 Layer and wire connectors
• CPC Class Codes: H01L 2924/00 Indexing scheme for arrangements or methods for connecting or disconnecting semiconductor or solid-state bodies as covered by H01L24/00
• CPC Class Codes: H01L 2924/00014 the subject-matter covered by the group, the symbol of which is combined with the symbol of this group, being disclosed without further technical details
• CPC Class Codes: H01L 2924/0002 Not covered by any one of groups H01L24/00, H01L24/00 and H01L2224/00
• CPC Class Codes: H01L 33/642 characterized by the shape

Abstract

Solid state lamps and bulbs comprising different combinations and arrangements of a light source, one or more wavelength conversion materials, regions or layers which are positioned separately or remotely with respect to the light source, and a separate diffuser. These are arranged on a heat sink in a manner that allows for the fabrication of lamps and bulbs that are efficient, reliable and cost effective and can provide an essentially omnidirectional emission pattern, even with a light source comprised of a co-planar arrangement of LEDs. Additionally, this arrangement allows aesthetic masking or concealment of the appearance of the conversion regions or layers when the lamp is not illuminated. Various embodiments of the invention may be used to address many of the difficulties associated with utilizing efficient solid state light sources such as LEDs in the fabrication of lamps or bulbs suitable for direct replacement of traditional incandescent bulbs. Embodiments of the invention can be arranged to fit recognized standard size profiles such as those ascribed to commonly used lamps such as incandescent light bulbs, while still providing emission patterns that comply with ENERGY STAR® standards.

Claims

1. A lighting device, comprising:

a light source on a first surface of a heat sink;

a diffuser on a second surface of said heat sink and spaced apart from said light source, wherein said diffuser is widest at a point that is not adjacent to said heat sink, wherein said second surface is below said first surface; and

a wavelength conversion material on said heat sink and between the light source and the diffuser and spaced apart from the light source and the diffuser, wherein said wavelength conversion element is widest at a point that is not adjacent to said heat sink, wherein said wavelength conversion material is a solid;

wherein said lighting device is configured to fit within the A19 envelope while emitting a substantially uniform emission pattern.

2. The lighting device of claim 1, emitting an emission pattern that complies with the ENERGY STAR®

requirements.

3. The lighting device of claim 1, wherein said light source comprises one or more light emitting diodes.

4. The lighting device of claim 1, wherein said wavelength conversion material comprises a phosphor carrier comprising a thermally conductive material.

5. The lighting device of claim 1, wherein said diffuser comprises a diffuser dome.

6. The lighting device of claim 1, wherein said diffuser comprises a diffusing material, wherein said diffuser comprises one or more areas covered by a greater amount of diffusing material.

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

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

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

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

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

12. 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 and diffuser provide a double-dome structure.

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 while 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, providing a steady state lumen output of 65 lumens per watt or more.

17. The lighting device of claim 1, providing a steady state lumen output of 80 lumens per watt or more.

18. The lighting device of claim 16, operating from less than 10 watts.

19. The lighting device of claim 1, providing a steady state output of 800 lumens at 10 watts or less.

20. The lighting device of claim 1, further comprising a layer to cover electrically conducting features below said diffuser dome and wavelength conversion material.

21. The lighting device of claim 1, wherein said light sources are mounted on a printed circuit board that is mounted to said heat sink, further comprising a layer to cover electrically conducting features on said PCB.

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

23. The lighting device of claim 1, emitting light with a color rendering index (CRI) of greater than 90.

24. The lighting device of claim 1, wherein the light emitted from the diffuser comprises a spatial uniformity that is within 20% of a mean value within a range of viewing angles.

25. The lighting device of claim 24, wherein said range of viewing angles is 0 to 135°

.

26. The lighting device of claim 24, comprising greater than 5% of total luminous flux in the 135 to 180°

viewing angles.

27. The lighting device of claim 1, wherein the lower edge of a frusto-spherical phosphor carrier is higher than the lower edge of said diffuser dome.

28. A lighting device, comprising:

a light source on a heat sink;

a diffuser on said heat sink and spaced apart from said light source; and

a wavelength conversion material on said heat sink and between the light source and the diffuser and spaced away from the light source and the diffuser, wherein said heat sink comprises a plurality of heat fins each comprising a lower angled portion that angles out from the central axis of said lighting device, and an upper portion that angles back toward said central axis and begins below where said fins meet the rest of said lighting device, emitting a substantially uniform emission pattern.

29. The lighting device of claim 28, configured to fit an A19 size envelope.

30. The lighting device of claim 28, wherein said diffuser comprises a diffuser dome and said heat fins do not extend beyond outer lateral edge of said diffuser dome.

31. The lighting device of claim 28, wherein said wavelength conversion material and said diffuser are substantially frusto-spherical such that said phosphor carrier and diffuser form a double-dome structure.

32. The lighting device of claim 28, wherein said heat sink comprise 20 to 60 heat fins.

33. The lighting device of claim 28, wherein said heat sink comprises 30 to 50 heat fins.

34. The lighting device of claim 28, wherein said heat sink comprises approximately 38 heat fins.

35. The lighting device of claim 28, wherein said lower section comprises an angle of 150°

or more from said lighting device central axis.

36. The lighting device of claim 28, wherein said upper section comprises a measured angle of 60°

or less.

37. The lighting device of claim 28, wherein said upper section comprises a measured angle of 50°

or less.

38. The lighting device of claim 28, wherein said upper section comprises a measured angle of approximately 42°

.

39. A solid state lamp, comprising solid state light source emitting light with an efficacy of 80 lumens per watt or more, and fitting within an A19 size envelope;

wherein said lamp further comprises a heat sink;

wherein said lamp comprises a diffuser on said heat sink;

wherein said heat sink comprises a plurality of fins, wherein each of said fins comprises an upper portion angling away from said lamp and a lower portion angling toward said lamp.

40. A solid state lamp, comprising solid state light source emitting light with an efficacy of 80 lumens per watt or more, and comprising an emission pattern compliant with ENERGY STAR®

performance requirements;

said lamp further comprising a diffuser on a heat sink and spaced apart from said light source and a conversion material between said light source and said diffuser, wherein said diffuser is widest at a point that is not adjacent to said heat sink;

wherein said heat sink comprises a plurality of fins, each of said fins comprising an angled upper surface angling away from said heat sink and an angled lower surface angling back toward said heat sink;

wherein no two angled upper surfaces form an angle of more than 45°

.

41. A solid state lamp, comprising solid state light source emitting light with an efficacy of 80 lumens per watt or more from 10 watts or less;

said lamp further comprising a diffuser on a heat sink and spaced apart from said light source and a conversion material between said light source and said diffuser, wherein said diffuser is widest at a point that is not adjacent to said heat sink;

wherein said heat sink comprises a plurality of fins comprising a first section angled away from said solid state lamp connected to a second section angled toward said solid state lamp.

42. A solid state lamp, comprising solid state light source emitting light with an efficacy of 80 lumens per watt or more, and comprising a color temperature of 3000 Kelvin or less;

said lamp further comprising a diffuser on a heat sink wherein said diffuser is widest at a point that is not adjacent to said heat sink;

said lamp further comprising a wavelength conversion element on said heat sink wherein said wavelength conversion element is widest at a point that is not adjacent to said heat sink, wherein said wavelength conversion material is a solid;

wherein said solid state lamp comprises one or more light sources;

wherein said one or more light sources emit a single color of light;

wherein said solid state lamp emits light having a normalized intensity of greater than 0.8 at angles greater than +120 degrees and less than −

120 degrees, wherein said angles are measured from a point on said diffuser, said point on a side of said diffuser opposite said heat sink.

43. The lamp of claim 42, emitting light comprising a color temperature of 2700 Kelvin or less.

44. A solid state lamp, comprising solid state light source emitting light with an efficacy of 80 lumens per watt or more, and comprising a lifetime of greater than 25,000 hours or more at an operating temperature of 25°

C. or more;

said lamp further comprising a diffuser on a heat sink wherein said diffuser is widest at a point that is not adjacent to said heat sink;

said lamp further comprising a wavelength conversion element on said heat sink wherein said wavelength conversion element is a solid element which is widest at a point that is not adjacent to said heat sink;

wherein said solid state lamp emits light having a normalized intensity of greater than 0.8 at angles greater than +120 degrees and less than −

120 degrees, wherein said angles are measured from a point on said diffuser, said point on a side of said diffuser opposite said heat sink;

wherein said solid state lamp comprises one or more light sources;

wherein said one or more light sources emit a single color of light.

45. A solid state lamp, comprising solid state light source emitting light with an efficacy of 80 lumens per watt or more, and comprising a lifetime of 50,000 hours or more at an operating temperature of 25°

C. or more;

said lamp further comprising a diffuser on a heat sink wherein said diffuser is widest at a point that is not adjacent to said heat sink;

said lamp further comprising a wavelength conversion element on said heat sink wherein said wavelength conversion element is a solid element which is widest at a point that is not adjacent to said heat sink;

wherein said solid state lamp emits light having a normalized intensity of greater than 0.8 at angles greater than +120 degrees and less than −

120 degrees, wherein said angles are measured from a point on said diffuser, said point on a side of said diffuser opposite said heat sink;

wherein said solid state lamp comprises one or more light sources;

wherein said one or more light sources emit a single color of light.