LED light bulbs

• US 8,596,821 B2
• Filed: 06/08/2010
• Issued: 12/03/2013
• 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.
• Primary Examiner(s): Husar, Stephen F
• Assistant Examiner(s): DUNWIDDIE, MEGHAN K
• Application Number:
  US12/796,555
• Publication Number:
  US 20110298371A1
• Time in Patent Office: 1,274 Days
• Field of Search: 362/249.01, 362/249.02, 362/249.14, 362/294, 362/311.02, 362/373, 362/800
• US Class Current: 362/249.02
• 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:

a substrate having patterned thereon at least one electrical trace and comprising at least one bend therein arranged to form multiple non-coplanar LED mounting surfaces of a substantially rigid upright support structure, wherein the substrate comprises multiple connectors extending beyond at least some LED mounting surfaces of the multiple non-coplanar LED mounting surfaces, and wherein the connectors are arranged for insertion into multiple recesses or compression fittings of a base element in conductive thermal communication with an externally accessible heatsink arranged between a threaded contact-defining end cap and a light-transmissive cover of a LED light bulb; and

a plurality of LEDs mounted to LED mounting surfaces of the substrate, arranged in electrical communication with the at least one trace, and arranged in conductive thermal communication with at least portions of the substrate.

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, further comprising any of a LED drive circuit element and a LED control circuit element mounted to, defined in, or defined on the substrate.

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

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

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

7. The LED light bulb of claim 6, wherein the threaded contact-defining end cap comprises a plurality of electrical contacts arranged to mate with an electrical socket to receive electric current, and wherein the plurality of electrical contacts are arranged to supply electric current to the LED light bulb.

8. The LED light bulb of claim 6, further comprising a cover defining an interior volume, wherein the plurality of LEDs and at least a portion of the substrate are disposed within the interior volume.

9. The LED light bulb of claim 8, wherein the cover comprises any of a diffuser, a lens, and a lumiphoric material.

10. The LED light bulb of claim 8, wherein the cover comprises a plurality of openings to enable air or other fluid to flow between the interior volume and an ambient environment.

11. The LED light bulb of claim 8, 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.

12. A method utilizing the LED light bulb of claim 6, comprising supplying electric current to the at least one electrical trace to illuminate the at least one LED.

13. A method for forming a LED light engine according to claim 1, the method comprising:

patterning a substantially planar substrate to define at least one electrical trace for a plurality of light emitting diodes (LEDs);

mounting a plurality of LEDs to the substrate in electrical communication with the at least one electrical trace; and

shaping the substrate to define at least one bend therein to form multiple non-coplanar LED mounting surfaces of a substantially rigid upright support structure for the plurality of LEDs.

14. The method of claim 13, wherein the at least one electrical trace comprises a plurality of electrical traces for the plurality of LEDs and for at least one electrical circuit element associated with the plurality of LEDs.

15. The method of claim 14, 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.

16. The method of claim 13, wherein the substrate comprises a metal core printed circuit board.

17. The method of claim 13, wherein the shaping of the substrate is performed after the mounting of the plurality of LEDs to the substrate.

18. The method of claim 13, wherein the shaping of the substrate includes forming a plurality of non-coplanar LED mounting surfaces adapted to support the plurality of LEDs.

19. The method of claim 13, further comprising arranging a cover that is at least partially transmissive of visible wavelengths over the substantially rigid upright support structure.

20. The method of claim 13, 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 multiple non-coplanar LED mounting surfaces of a substantially rigid upright support structure.

21. 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 LED light engine according to claim 1, wherein the plurality of LEDs and at least a portion of the substrate are disposed within the interior volume.

22. The LED light bulb of claim 21, wherein said material has a thermal conductivity of at least about 100 W/(m·

°

K) at about 25°

C.

23. The LED light bulb of claim 21, wherein the cover comprises a plurality of fins.

24. The LED light bulb of claim 23, wherein the fins are formed by sintering.

25. The LED light bulb of claim 21, wherein the cover serves as an optical diffuser or at least one lens.

26. The LED light bulb of claim 21, wherein the cover has associated therewith a lumiphoric material arranged to receive emissions from the plurality of LEDs and responsively emit spectral output with a peak wavelength differing from a peak wavelength of emissions of the plurality of LEDs.

27. The LED light bulb of claim 21, 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.

28. The LED light bulb of claim 21, wherein the cover comprises at least one opening to enable air or other fluid to flow between the interior volume and an ambient environment.

29. The LED light bulb of claim 28, further comprising at least one baffle arranged to prevent unobstructed visibility of the plurality of LEDs through the at least one opening.

30. The LED light bulb of claim 29, wherein the at least one baffle is arranged within the interior volume.

31. The LED light bulb of claim 21, 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.

32. The LED light bulb of claim 21, wherein the at least one LED plurality of LEDs comprises a heat spreader arranged in conductive thermal communication with the plurality of LEDs and in conductive thermal communication with the cover.

33. 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 LED light engine according to claim 1, wherein the plurality of LEDs and at least a portion of the substrate are disposed within the interior volume;

a base element supporting the substrate and comprising a plurality of electrical conductors in electrical communication with the plurality of LEDs; and

a threaded contact-defining end cap including first and second electrical contacts extending from the base element and arranged to receive electric current, wherein the first and second electrical contacts are in electrical communication with the plurality of electrical conductors.

34. The LED light bulb of claim 33, wherein the plurality of LEDs are adapted to emit light having at least one peak wavelength, and the cover comprises at least one lumiphoric material adapted to receive light from the plurality of LEDs and responsively emit light having at least one other peak wavelength that differs from the at least one peak wavelength.

35. The LED light bulb of claim 33, further comprising an externally accessible heatsink including a plurality of fins arranged to dissipate heat generated by the plurality of LEDs.

36. The LED light bulb of claim 33, 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.

37. The LED light engine of claim 1, wherein at least portions of at least some LED mounting surfaces of the multiple non-coplanar LED mounting surfaces are longitudinally arranged for placement substantially parallel to a longitudinal axis of a LED light bulb.

38. The LED light engine of claim 1, wherein the multiple connectors are arranged to make at least two of:

a mechanical connection, a thermal connection, and an electrical connection between the substrate and the base element.

39. The LED light engine of claim 1, wherein the multiple connectors are arranged to make at least one mechanical connection, at least one thermal connection, and at least one electrical connection between the substrate and the base element.

40. The LED light engine of claim 1, wherein the multiple connectors include at least one edge connector.

41. A LED light bulb comprising the LED light engine of claim 1, a base element, a threaded contact-defining end extending from the base element, a light-transmissive cover, and an externally accessible heatsink exposed to an ambient environment and arranged between the threaded contact-defining end and the light-transmissive cover, wherein the multiple connectors are inserted into multiple recesses or compression fittings of the base element.

42. The LED light bulb of claim 41, wherein the cover defines an interior volume, and wherein the plurality of LEDs and at least a portion of the substrate are disposed within the interior volume.

43. The LED light bulb of claim 42, wherein the threaded contact-defining end cap comprises a plurality of electrical contacts arranged to mate with an electrical socket and receive electric current.

44. The LED light bulb of claim 41, wherein the externally accessible heatsink is arranged along an externally accessible surface of the base element.

45. The LED light bulb of claim 41, wherein the externally accessible heatsink includes a plurality of fins.

46. The LED light bulb of claim 41, wherein at least portions of at least some LED mounting surfaces of the multiple non-coplanar LED mounting surfaces are longitudinally arranged for placement substantially parallel to a longitudinal axis of a LED light bulb.

47. The LED light bulb of claim 41, wherein at least one control circuit element arranged to control operation of the plurality of LEDs is arranged in the base element.

48. The LED light bulb of claim 41, wherein at least a portion of the base element comprises a tubular support column.

49. The LED light bulb of claim 48, wherein the support column comprises metal.

50. The LED light bulb of claim 48, wherein at least a portion of the support column is contained within the interior volume of the cover.

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

a 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; and

a cover defining an interior volume, wherein the at least one LED is disposed within the interior volume, wherein the cover comprises a plurality of openings to enable air or other fluid to flow between the interior volume and an ambient environment.

52. The LED light bulb of claim 51, further comprising at least one baffle arranged to prevent unobstructed visibility of the at least one LED through the plurality of openings.

53. The LED light bulb of claim 52, wherein the at least one baffle is arranged within the interior volume.

54. The LED light bulb of claim 51, further comprising at least one additional opening defined in a base portion of the light bulb disposed outside the cover.

55. The LED light bulb of claim 54, 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.

56. The LED light bulb of claim 51, further comprising a filter element arranged inhibit passage of dust or other particulate matter through the plurality of openings.

57. The LED light bulb of claim 56, further comprising at least one sensor arranged to sense a condition indicative of a need for the filter element to be cleaned or changed.