Compact Heat Sinks and Solid State Lamp Incorporating Same

• US 20110090686A1
• Filed: 10/20/2009
• Published: 04/21/2011
• Est. Priority Date: 10/20/2009
• Status: Active Grant

• Current Assignee: CREE Incorporated (Wolfspeed, Inc.)
• Original Assignee: Cree Lighting Company (Ideal Industries Incorporated)
• Inventors: Pickard, Paul Kenneth
• Granted Patent: US 9,243,758 B2
• Time in Patent Office: Days
• US Class Current: 362/235
• CPC Class Codes: F21K 9/232 specially adapted for generating an essentially omnidirectional light distribution, e.g. with a glass bulb
• CPC Class Codes: F21V 29/74 with fins or blades
• CPC Class Codes: F21V 29/75 with fins or blades having different shapes, thicknesses or spacing
• CPC Class Codes: F21V 29/763 the planes containing the fins or blades having the direction of the light emitting axis
• CPC Class Codes: F21V 29/777 the planes containing the fins or blades having directions perpendicular to the light emitting axis
• CPC Class Codes: F21V 29/83 the elements having apertures, ducts or channels, e.g. heat radiation holes
• CPC Class Codes: F21V 29/86 Ceramics or glass
• CPC Class Codes: F21Y 2107/00 Light sources with three-dimensionally disposed light-generating elements
• CPC Class Codes: F21Y 2107/30 on the outer surface of cylindrical surfaces, e.g. rod-shaped supports having a circular or a polygonal cross section
• CPC Class Codes: F21Y 2115/10 Light-emitting diodes [LED]

Abstract

A solid state lamp with efficient heat sink arrangement. To provide adequate cooling utilizing a defined form factor, such as that of the A-lamp incandescent bulb, the interior volume is used more efficiently. As one example, a solid state lamp employs a heat sink with inward facing fins. Solid state light sources, such as light emitting diodes (LEDs), are mounted on the exterior of the heat sink. An air path for convective flow is established through the center of the lamp.

Claims

1. A solid state lamp, comprising:

at least two solid state light emitters, the at least two solid state light emitters being disposed so that a primary axis of a light output of one of the at least two light emitters is in a direction in which the other of the at least two solid state light emitters directs no light; and

a heat sink disposed between the at least two light emitters and defining a space between the at least two light emitters that is exposed to an environment for heat dissipation.

2. The solid state lamp according to claim 1, further comprising at least one lens disposed opposite the heat sink from at least one of the at least two solid state light emitters.

3. The solid state lamp according to claim 2, wherein the heat sink and the lens define at least one cavity in which the solid state light emitters are disposed.

4. The solid state lamp according to claim 3, further comprising a reflector in the at least one cavity.

5. The solid state lamp according to claim 4, further comprising a diffuser associated with the at least one cavity to diffuse light from at least one of the solid state light emitters.

6. The solid state lamp according to claim 1, wherein the heat sink comprises a substantially hollow structure having fins disposed therein, the hollow portion of the heat sink being disposed opposite from the direction of light emission by the at least two solid state light emitters.

7. The solid state lamp according to claim 1, wherein the lamp is contained within the envelope of an A lamp.

8. The solid state lamp according to claim 1, wherein the lamp has a correlated color temperature of greater than 2500 K and less than 4500 K.

9. The solid state lamp according to claim 8, wherein the lamp has a color rendering index of 90 or greater.

10. The solid state lamp according to claim 1, wherein the lamp has a lumen output of about 600 lumens or greater.

11. The solid state lamp according to claim 10, wherein the lamp has a light output of from about 0°

to about 150°

axially symmetric.

12. A solid state lamp comprising:

a heat sink comprising a plurality of mounting surfaces, the plurality of mountings surfaces defining an opening that extends from a bottom to a top of the heat sink at least one of the mounting surfaces having at least one fin that extends into the opening;

light emitting diodes on the heat sink; and

at least one lens.

13. The solid state lamp according to claim 12, comprising:

a lower portion comprising an electrical contact;

an upper portion comprising the heat sink; and

a stand for connecting the lower portion and the upper portion configured to allow air flow between the upper portion and the lower portion.

14. The solid state lamp according to claim 13, wherein the electrical contact comprises one of an Edison screw contact, a GU24 contact or a bayonet contact.

15. The solid state lamp according to claim 13, wherein the upper portion has a form factor substantially corresponding to an A lamp.

16. The solid state lamp according to claim 13, wherein the lamp provides at least about 600 lumens while passively dissipating at least about 6 W of heat.

17. The solid state lamp according to claim 13, further comprising driver circuitry disposed within the lower portion to provide a selfballasted lamp.

18. A heat sink for a solid state lighting device, comprising:

a main body section that defines a central opening extending longitudinally along the main body section;

at least one inwardly extending fin extending from the main body section into the central opening.

19. The heat sink according to claim 18, wherein the at least one outwardly facing mounting surface comprises a plurality of outwardly facing mounting surfaces.

20. The heat sink according to claim 18, wherein the at least one inwardly extending tin comprises a plurality of inwardly extending fins.

21. The heat sink of claim 18 having an outer profile small enough to fit within the profile of an A lamp.