High efficiency solid state lamp and bulb

• US 9,057,511 B2
• Filed: 02/24/2011
• Issued: 06/16/2015
• 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, Letoquin, Ronan, Keller, Bernd, Tarsa, Eric, Pickard, Paul, Lay, James Michael, Tong, Tao, Youmans, Mark, Lowes, Theodore, Medendorp, Nicholas W. Jr., Van De Ven, Antony, Negley, Gerald
• Primary Examiner(s): Roy, Sikha
• Application Number:
  US13/034,501
• Publication Number:
  US 20120057327A1
• Time in Patent Office: 1,573 Days
• Field of Search: 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 29/745 the fins or blades being planar and inclined with respect to the joining surface from which the fins or blades extend
• 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 29/85 characterised by the material liquid coolants F21V29/56
• 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: 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]
• 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 2924/00012 Relevant to the scope of the group, the symbol of which is combined with the symbol of this group
• 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 2924/181 Encapsulation

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 omni-directional 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 solid state lamp, comprising:

a heat sink with a plurality of heat fins;

a solid state light source mounted on a top surface of said heat sink;

a phosphor carrier on said heat sink, over and spaced apart from said light source, such that an optical cavity is formed by the space between said phosphor carrier and said heat sink top surface; and

a diffuser on said heat sink, over and spaced apart from said phosphor carrier, wherein said phosphor carrier and said diffuser are substantially frusto-spherical such that said phosphor carrier and diffuser provide a double-dome structure, wherein said lamp fits within a standard size profile, and emits a substantially uniform emission pattern, wherein said solid state light source is configured such that there are no surfaces within said optical cavity to block sideways emission from said solid state light source, wherein said diffuser extends below said top surface of said heat sink such that at least some light is emitted in a downward direction when said solid state lamp is in operation.

2. The solid state lamp of claim 1, wherein said standard size envelope includes one from the group A19, A21 and A23.

3. The solid state lamp of claim 1, wherein said substantially uniform emission pattern meets ENERGY STAR®

emission requirements.

4. The solid state lamp of claim 1, providing a steady state output of 800 lumens at 10 watts or less.

5. The solid state lamp of claim 1, wherein said heat fins to not extend beyond the lateral edge of said diffuser.

6. A solid state lamp, comprising a solid state light source on a surface of said solid state lamp and at least one diffuser dome remote from said solid state light source such that an optical cavity is formed by the space between said diffuser dome and said surface of said solid state lamp, said solid state light source emitting light with an efficacy of 80 lumens per watt or more, comprising a color rendering index of greater than 80, and emitting omnidirectionally, wherein said solid state light source is configured such that there are no surfaces within said optical cavity to block sideways emission from said solid state light source, wherein said diffuser dome extends below said surface of said solid state lamp with said solid state light source thereon, such that at least some light is emitted in a downward direction when said solid state lamp is in operation;

and

a phosphor remote from said solid state light source.

7. The lamp of claim 6, emitting light comprising a color rendering index at or greater than 90.

8. The lamp of claim 6, further comprising a phosphor carrier.

9. A solid state lamp, comprising a solid state light source on a surface of said solid state lamp and at least one diffuser dome remote from said solid state light source such that an optical cavity is formed by the space between said diffuser dome and said surface of said solid state lamp, said solid state light source emitting light with an efficacy of 80 lumens per watt or more, comprising a double dome diffuser and conversion material arrangement, and emitting omnidirectionally, wherein said solid state light source is configured such that there are no device side surfaces to block sideways light emission to said diffuser, wherein said diffuser dome extends below said surface of said solid state lamp with said solid state light source thereon, such that at least some light is emitted in a downward direction when said solid state lamp is in operation.