LED LIGHT BULBS

• US 20110298371A1
• Filed: 06/08/2010
• Published: 12/08/2011
• Est. Priority Date: 06/08/2010
• Status: Active Grant

• Current Assignee: IDEAL Industries Lighting, LLC (Ideal Industries Incorporated)
• Original Assignee: CREE Incorporated (Wolfspeed, Inc.)
• Inventors: Brandes, George R., Garceran, Julio A.
• Granted Patent: US 8,596,821 B2
• Time in Patent Office: Days
• US Class Current: 315/32
• CPC Class Codes: F21K 9/23 Retrofit light sources for lighting devices with a single fitting for each light source, e.g. for substitution of incandescent lamps with bayonet or threaded fittings
• 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 9/238 Arrangement or mounting of circuit elements integrated in the light source
• CPC Class Codes: F21K 9/60 Optical arrangements integrated in the light source, e.g. for improving the colour rendering index or the light extraction
• 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: F21K 9/90 Methods of manufacture
• CPC Class Codes: F21V 23/005 the substrate is supporting also the light source
• CPC Class Codes: F21V 23/02 the elements being transformers, impedances or power supply units, e.g. a transformer with a rectifier
• CPC Class Codes: F21V 29/506 of globes, bowls or cover glasses
• CPC Class Codes: F21V 29/507 of means for protecting lighting devices from damage, e.g. housings
• CPC Class Codes: F21V 29/51 using condensation or evaporation of a fluid, e.g. heat pipes
• CPC Class Codes: F21V 29/57 characterised by control arrangements
• CPC Class Codes: F21V 29/677 the fans being used for discharging
• CPC Class Codes: F21V 29/70 characterised by passive heat-dissipating elements, e.g. heat-sinks
• CPC Class Codes: F21V 29/74 with fins or blades
• CPC Class Codes: F21V 29/83 the elements having apertures, ducts or channels, e.g. heat radiation holes
• CPC Class Codes: F21V 3/049 Patterns or structured surfaces for diffusing light, e.g. frosted surfaces
• CPC Class Codes: F21V 3/08 the material comprising photoluminescent substances
• CPC Class Codes: F21V 3/12 the coatings comprising photoluminescent substances
• CPC Class Codes: F21Y 2105/10 comprising a two-dimensional array of point-like 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 2107/40 : on the sides of polyhedrons, e.g. cubes or pyramids
• CPC Class Codes: F21Y 2115/10 : Light-emitting diodes [LED]
• CPC Class Codes: F21Y 2115/30 : Semiconductor lasers
• CPC Class Codes: H05K 2201/047 : Box-like arrangements of PCBs
• CPC Class Codes: H05K 2201/10106 : Light emitting diode [LED]
• CPC Class Codes: Y10S 362/80 : Light emitting diode
• CPC Class Codes: Y10T 29/4913 : Assembling to base an electrical component, e.g., capacitor, etc.

Abstract

LED light bulbs include openings in base or cover portions, and optional forced flow elements, for convective cooling. Thermally conductive optically transmissive material may be used for cooling, optionally including fins. A LED light engine may be fabricated from a substrate via planar fabrication techiques and shaped to form a substantially rigid upright support structure. Mechanical, electrical, and thermal connections may be made between a LED light engine and a LED light bulb.

Claims

1. A light emitting diode (LED) light engine adapted for use in a LED light bulb, the LED light engine comprising at least one LED mounted to a substrate having patterned thereon at least one electrical trace, the substrate comprising at least one heat conduit portion with which the at least one LED is arranged in conductive thermal communication, wherein the substrate includes at least one bend therein to form a substantially rigid upright support structure for the at least one LED.

2. The LED light engine of claim 1, wherein the at least one electrical trace comprises a plurality of electrical traces.

3. The LED light engine of claim 1, wherein the at least one heat conduit portion comprises, or is in conductive thermal communication with, a heatsink

4. The LED light engine of claim 1, further comprising any of a LED drive circuit element and a LED control circuit element mounted to, defined in, or defined on the substrate.

5. The LED light engine of claim 1, wherein the substrate comprises a metal core printed circuit board.

6. The LED light engine of claim 1, wherein the substrate comprises a stamped metal layer and at least one electrically insulating layer.

7. The LED light engine of claim 1, wherein the at least one heat conduit portion is electrically isolated from the at least one LED.

8. The LED light engine of claim 1, wherein the at least one LED comprises a plurality of LEDs, and the substrate includes a plurality of non-coplanar LED support surfaces adapted to support the plurality of LEDs.

9. The LED light engine of claim 1, wherein the substrate comprises at least one edge connector adapted to engage at least one electrical contact of a socket or fixture to supply electric current to the at least one LED.

10. A LED light bulb comprising the LED light engine of claim 1.

11. The LED light bulb of claim 10, including a base end comprising a plurality of electrical contacts arranged to mate with an electrical receptacle to receive electric current, wherein the plurality of electrical contacts are arranged to supply electric current to the LED light bulb.

12. The LED light bulb of claim 10, further comprising a cover defining an interior volume, wherein the at least one LED is disposed within the interior volume.

13. The LED light bulb of claim 10, wherein the cover comprises any of a diffuser, a lens, and a lumiphoric material.

14. The LED light bulb of claim 12, wherein the cover comprises a plurality of openings to enable air or other fluid to flow between the interior volume and an ambient environment.

15. The LED light bulb of claim 12. wherein at least a portion of the cover comprises a material having visible spectrum transmittance of least about 80% and a thermal conductivity of at least 25 W/(m·

°

K) at about 25°

C., and the cover is in conductive thermal communication the at least one LED.

16. A method utilizing the LED light bulb of claim 10, comprising supplying electric current to the at least one electrical trace to illuminate the at least one LED.

17. A method comprising:

patterning a substantially planar substrate to define at least one electrical trace for at least one light emitting diode (LED);

mounting at least one LED to the substrate; and

shaping the substrate to define at least one bend therein to form at least one substantially rigid upright support structure for the at least one LED.

18. The method of claim 17, wherein the at least one electrical trace comprises a plurality of electrical traces for the at least one LED and for at least one electrical circuit element associated with the at least one LED.

19. The method of claim 18, wherein the at least one electrical circuit element comprises at least one of a LED drive circuit element and a LED control circuit element, the method further comprising mounting to, defining in, or defining on the substrate the at least one of a LED drive circuit element and a LED control circuit element.

20. The method of claim 17, wherein the substrate comprises a metal core printed circuit board.

21. The method of claim 17, wherein the substrate comprises a heatsink portion, the method further comprising mounting the at least one LED to the substrate in conductive thermal communication with the heatsink portion.

22. The method of claim 17, wherein the shaping of the substrate is performed after the mounting of the at least one LED to the substrate.

23. The method of claim 17, wherein the at least one LED comprises a plurality of LEDs, and the shaping of the substrate includes forming a plurality of non-coplanar LED support surfaces adapted to support the plurality of LEDs.

24. The method of claim 17, further comprising arranging a cover that is at least partially transmissive of visible wavelengths over the substantially rigid upright support structure.

25. The method of claim 17, further comprising forming on the substrate at least one edge connector adapted to engage at least one electrical contact of a socket or fixture to supply electric current to the at least one LED.

26. The method of claim 17, wherein the at least one trace comprises a plurality of electrical traces for a plurality of LEDs and for a plurality of electrical circuit elements, the method further comprising cutting the substrate into a plurality of segments, and shaping the plurality of segments to define at least one bend in each segment to form a plurality of substantially rigid upright support structures for the plurality of LEDs.

27. A light emitting diode (LED) light bulb comprising:

a cover defining an interior volume, wherein at least a portion of the cover comprising a material having visible spectrum transmittance of least about 80% and a thermal conductivity of at least 25 W/(m·

°

K) at about 25°

C.; and

a substrate supporting at least one LED, wherein the at least one LED and at least a portion of the substrate are disposed within the interior volume.

28. The LED light bulb of claim 27, wherein said material has a thermal conductivity of at least about 100 W/(m·

°

K) at about 25°

C.

29. The LED light bulb of claim 27, wherein the cover comprises a plurality of fins.

30. The LED light bulb of claim 29, wherein the fins are formed by sintering.

31. The LED light bulb of claim 27, wherein the cover serves as an optical diffuser or at least one lens.

32. The LED light bulb of claim 27, wherein the cover has associated therewith a lumiphoric material arranged to downconvert emissions from the at least one LED.

33. The LED light bulb of claim 27, wherein substantially all of the cover comprises said material having visible spectrum transmittance of least about 80% and a thermal conductivity of at least 25 W/(m·

°

K) at about 25°

C.

34. The LED light bulb of claim 27, wherein the cover comprises at least one opening to enable air or other fluid to flow between the interior volume and an ambient environment.

35. The LED light bulb of claim 34, further comprising at least one baffle arranged to prevent unobstructed visibility of the at least one LED through the at least one opening.

36. The LED light bulb of claim 35, wherein the at least one baffle is arranged within the interior volume.

37. The LED light bulb of claim 27, wherein the cover comprises a first portion comprising said material having visible spectrum transmittance of least about 80% and a thermal conductivity of at least 25 W/(m·

°

K), and a second portion having a visible spectrum transmittance of less than about 80% and a thermal conductivity of greater than 25 W/(m·

°

K), wherein the first portion and the second portion are coupled along an interface arranged to promote conductive heat transfer between the first portion and the second portion.

38. The LED light bulb of claim 27, wherein the at least one LED further comprising a heat spreader arranged in conductive thermal communication with the at least one LED and in conductive thermal communication with the cover.

39. The LED light bulb of claim 27, further comprising:

at least one electrical conductor arranged to supply electric current to the at least one LED; and

at least one electrical contact arranged to mate with an electrical receptacle to receive electric current, wherein the at least one electrical contact is in electrical communication with the at least one electrical conductor.

40. A light emitting diode (LED) light bulb comprising:

a cover defining an interior volume, the cover comprising a material adapted to transmit at least a portion of light in the visible spectrum;

at least one LED disposed within the interior volume;

a support column comprising a plurality of electrical conductors in electrical communication with the at least one LED; and

first and second electrical contacts disposed in or on the support column and arranged to mate with an electrical receptacle to receive electric current, wherein the first and second electrical contacts are in electrical communication with the plurality of electrical conductors;

wherein a portion of the support column is disposed outside of the interior volume and is exposed to an ambient environment.

42. The LED light bulb of claim 40, wherein the at least one LED comprises a plurality of LEDs.

43. The LED light bulb of claim 40, wherein the at least one LED comprises light having at least one peak wavelength, and the cover comprises at least one lumiphoric material adapted to receive light from the at least one LED and responsively emit light having at least one other peak wavelength that differs from the at least one peak wavelength.

44. The LED light bulb of claim 40, wherein:

at least a portion of the support column has a hollow core;

the support column defines at least one first opening disposed within the interior volume and arranged for passage of fluid;

the support column defines at least one second opening disposed outside of the interior volume and exposed to an ambient environment; and

each of the at least one first opening and the at least one second opening is in fluid communication with the hollow core.

45. The LED light bulb of claim 40, wherein the support column comprises at least one heat transfer device arranged to promote dissipation of heat from the substrate to the ambient environment.

46. The LED light bulb of claim 45, wherein the at least one heat transfer device comprises a fan.

47. The LED light bulb of claim 45, wherein the at least one heat transfer device comprises a heatpipe.

48. The LED light bulb of claim 45, wherein the at least one heat transfer device comprises a plurality of fins.

49. The LED light bulb of claim 40, further comprising a cap disposed along an end of the support column distal from the substrate, wherein the cap includes the first and second electrical conductors.

50. The LED light bulb of claim 40, wherein at least an outer portion of the support column comprises an electrically insulating material.

51. The LED light bulb of claim 50, wherein the support column comprises an electrically conductive inner portion, and the electrically insulating material comprises a coating or covering disposed over the electrically conductive inner portion.

52. The LED light bulb of claim 40, wherein at least a portion of the cover comprises a material having visible spectrum transmittance of least about 80% and a thermal conductivity of at least 25 W/(m·

°

K) at about 25°

C.

41. The LED light bulb of claim 41, further comprising a substrate within the interior volume, wherein the at least one LED is arranged on or over the substrate, and the substrate is supported by the support column.

53. A light emitting diode (LED) light bulb comprising:

a cover defining an interior volume, the cover comprising a material adapted to transmit at least a portion of light in the visible spectrum;

a substrate supporting at least one LED, wherein the at least one LED and at least a portion of the substrate are disposed within the interior volume; and

at least one opening defined in the cover, wherein the at least one opening is in fluid communication with an ambient environment.

54. The LED light bulb of claim 53, further comprising at least one baffle arranged to prevent unobstructed visibility of the at least one LED through the at least one opening.

55. The LED light bulb of claim 54, wherein the at least one baffle is arranged within the interior volume.

56. The LED light bulb of claim 53, wherein the cover comprises a plurality of openings to enable air or other fluid to flow between the interior volume and an ambient environment.

57. The LED light bulb of claim 53, further comprising at least one additional opening defined in at least one of (a) the cover and (b) a base portion of the light bulb disposed outside the cover.

58. The LED light bulb of claim 57, further comprising a fluid circulation element adapted to cause air or other fluid to flow through the at least one opening and the at least one additional opening.

59. The LED light bulb of claim 53, further comprising a filter element arranged inhibit passage of dust or other particulate matter through the at least one opening.

60. The LED light bulb of claim 59, further comprising at least one sensor arranged to sense a condition indicative of a need for the filter element to be cleaned or changed.