Lighting device with reverse tapered heatsink
View Patent ↗A solid state lighting devices includes a heatsink having a first end arranged proximate to a base end, and a second end arranged between the first end and a solid state emitter, wherein at least a portion of the heatsink is wider at point intermediate the first end and the second end than the width of the heatsink at the second end. Such reverse angled heatsink reduces obstruction of light. A heatsink may include multiple fins and a heatpipe.
1. A solid state lighting device comprising:
a base end;
at least one solid state emitter;
a light-transmissive cover arranged to cover the at least one solid state emitter and transmit at least a portion of emissions generated by the at least one solid state emitter; and
a heatsink disposed between the base end and the at least one solid state emitter, and arranged to dissipate heat generated by the at least one solid state emitter;
wherein:
the heatsink comprises a first heatsink end and comprises a first width at the first heatsink end;
the heatsink comprises a second heatsink end and comprises a second width at the second heatsink end;
the base end is closer to the first heatsink end than to the second heatsink end;
at least a portion of the heatsink disposed between the first heatsink end and the second heatsink end comprises a third width that is greater than the second width; and
the heatsink comprises a maximum width dimension that is substantially equal to a corresponding maximum width dimension of the cover.
2. The solid state lighting device of claim 1 , wherein the cover comprises a height dimension that is substantially smaller than a height dimension of the heatsink.
3. The solid state lighting device of claim 1 , wherein the cover comprises a diffuser arranged to diffuse light emitted by the at least one solid state emitter.
4. The solid state lighting device of claim 1 , wherein the cover comprises a curved or hemispherical outer surface.
5. The solid state lighting device of claim 1 , wherein each of the first heatsink end, the second heatsink end, and the at least a portion of the heatsink end having the third width is exposed to an ambient air environment.
6. The solid state lighting device of claim 1 , wherein the second heatsink end is arranged to be illuminated with emissions generated by the at least one solid state emitter.
7. The solid state lighting device of claim 1 , wherein the base end comprises at least one electrical contact.
8. The solid state lighting device of claim 1 , having a substantially central axis extending in a direction between the base end and an emitter mounting area, wherein the heatsink is arranged to permit unobstructed emission of light generated by the at least one solid state emitter according to each emission half-angle of at least about 135 degrees relative to the substantially central axis around an entire lateral perimeter of the solid state lighting device.
9. The solid state lighting device of claim 1 , having a substantially central axis extending in a direction between the base end and an emitter mounting area, wherein the heatsink is arranged to permit unobstructed emission of light generated by the at least one solid state emitter according to each emission half-angle of at least about 145 degrees relative to the substantially central axis around an entire lateral perimeter of the solid state lighting device.
10. The solid state lighting device of claim 1 , wherein the heatsink comprises a plurality of fins.
11. The solid state lighting device of claim 10 , wherein at least a portion of the plurality of fins is arranged in a spiral shape.
12. The solid state lighting device of claim 10 , wherein at least a widest portion of each fin of the plurality of fins is exposed along a periphery of the solid state lighting device.
13. The solid state lighting device of claim 1 , wherein the heatsink is adapted to dissipate a steady state thermal load of at least about 4 watts in an ambient air environment of about 35° C. while maintaining a junction temperature of the at least one solid state emitter at or below about 85° C.
14. The solid state lighting device of claim 1 , wherein the heatsink is adapted to dissipate a steady state thermal load of at least about 8 watts in an ambient air environment of about 35° C. while maintaining a junction temperature of the at least one solid state emitter at or below about 85° C.
15. The solid state lighting device of claim 1 , wherein an upper boundary of the heatsink provides a linear boundary arranged perpendicular to a central longitudinal axis definable through the solid state lighting device.
16. The solid state lighting device of claim 1 , further comprising any of a plurality of electrical conductors and a plurality of electrical circuit elements disposed within the heatsink.
17. The solid state lighting device of claim 1 , further comprising at least one column or emitter support structure extending from the base end through at least a portion of the heatsink.
18. The solid state lighting device of claim 1 , wherein the at least one solid state emitter is arranged in a leadframe-based solid state emitter package arranged under or within the cover.
19. The solid state lighting device of claim 1 , wherein the at least one solid state emitter comprises a plurality of solid state emitters.
20. A solid state lighting device comprising:
a base end;
at least one solid state emitter;
a light-transmissive cover comprising a curved or hemispherical outer surface, and arranged to cover the at least one solid state emitter and transmit at least a portion of emissions generated by the at least one solid state emitter; and
a heatsink comprising a plurality of fins disposed between the base end and the at least one solid state emitter, and arranged to dissipate heat generated by the at least one solid state emitter;
wherein:
the heatsink comprises a first heatsink end and comprises a first width at the first heatsink end;
the heatsink comprises a second heatsink end and comprises a second width at the second heatsink end;
the base end is closer to the first heatsink end than to the second heatsink end;
at least a portion of the heatsink disposed between the first heatsink end and the second heatsink end comprises a third width that is greater than the second width;
the solid state lighting device comprises a substantially central axis extending in a direction between the base end and an emitter mounting area, wherein the heatsink is arranged to permit unobstructed emission of light generated by the at least one solid state emitter according to each emission half-angle of at least about 135 degrees relative to the substantially central axis around an entire lateral perimeter of the solid state lighting device.
21. The solid state lighting device of claim 20 , wherein the heatsink comprises a maximum width dimension that is substantially equal to a corresponding maximum width dimension of the cover.
22. The solid state lighting device of claim 20 , wherein the second heatsink end is arranged to be illuminated with emissions generated by the at least one solid state emitter.
23. The solid state lighting device of claim 20 , wherein at least a portion of the plurality of fins is arranged in a spiral shape.
24. The solid state lighting device of claim 20 , wherein at least a widest portion of each fin of the plurality of fins is exposed along a periphery of the solid state lighting device.
25. The solid state lighting device of claim 20 , wherein the at least one solid state emitter is arranged in a leadframe-based solid state emitter package arranged under or within the cover.
26. The solid state lighting device of claim 20 , wherein the cover comprises a height dimension that is substantially smaller than a height dimension of the heatsink.
27. The solid state lighting device of claim 20 , wherein the heatsink is arranged to permit unobstructed emission of light generated by the at least one solid state emitter according to each emission half-angle of at least about 145 degrees relative to the substantially central axis around an entire lateral perimeter of the solid state lighting device.