Linear LED lamp

• US 8,587,185 B2
• Filed: 12/08/2010
• Issued: 11/19/2013
• Est. Priority Date: 12/08/2010
• Status: Active Grant

• Current Assignee: IDEAL Industries Lighting, LLC (Ideal Industries Incorporated)
• Original Assignee: CREE Incorporated (Wolfspeed, Inc.)
• Inventors: Negley, Gerry, van de Ven, Antony Paul, Pickard, Paul
• Primary Examiner(s): HINES, ANNE M
• Application Number:
  US12/962,847
• Publication Number:
  US 20120146503A1
• Time in Patent Office: 1,077 Days
• Field of Search: 313/22, 313/46, 313502-512, 257/88, 362/101
• US Class Current: 313/46
• CPC Class Codes: F21K 9/27 Retrofit light sources for lighting devices with two fittings for each light source, e.g. for substitution of fluorescent tubes
• 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 9/62 using mixing chambers, e.g. housings with reflective walls
• CPC Class Codes: F21Y 2103/10 comprising a linear array of point-like light-generating elements
• CPC Class Codes: F21Y 2115/10 Light-emitting diodes [LED]
• CPC Class Codes: Y10T 29/49002 Electrical device making

Abstract

A linear LED lamp is disclosed. Embodiments of the invention can provide an LED-based replacement lamp for a linear or “tube-type” bulb or a bulb with a linear filament or element. By filling the void within the lamp with an optically transmissive fluid to cool the LEDs without the use of a traditional heat sink, the light blocking effects of such a heat sink can be avoided. Thus, the LED replacement lamp can emit light in a substantially omnidirectional pattern. In some embodiments, the optically transmissive fluid medium is a liquid. In some embodiments, the optically transmissive fluid medium is a gel. An index matching medium can be used as the optically transmissive fluid medium. A color mixing treatment can optionally be included to eliminate color tints in cases where multiple LEDs of different colors are used to produce white light.

Claims

1. A lamp comprising:

an enclosure having an electrical connection;

a linear array of LED devices disposed in the enclosure to be operable to emit light when energized through the electrical connection;

an optically transmissive, fluid medium contained in the enclosure in thermal communication with the linear array of LED devices; and

a color mixing treatment permeated with the fluid medium.

2. The lamp of claim 1 wherein the linear array of LED devices emits light in a substantially omnidirectional pattern.

3. The lamp of claim 2 wherein the optically transmissive, fluid medium is selected from a group consisting of a liquid and a gel.

4. The lamp of claim 3 wherein the optically transmissive, fluid medium is an index matching medium.

5. The lamp of claim 4 wherein the color mixing treatment is selected from a group consisting of an open cell foam and a nanowire.

6. The lamp of claim 4 further comprising a power supply coupled to the electrical connection.

7. The lamp of claim 6 wherein the linear array of LED devices further comprises a plurality of LEDs wherein each LED includes an optically transmissive substrate.

8. The lamp of claim 7 wherein the optically transmissive substrate is selected from a group consisting of sapphire and silicon carbide.

9. The lamp of claim 8 wherein the color mixing treatment is selected from a group consisting of an open cell foam and a nanowire.

10. The lamp of claim 6 further comprising a phosphor disposed to be energized by the linear array of LED devices.

11. A method of assembling a lamp, the method comprising:

placing a linear array of LED devices in an enclosure;

placing a color mixing treatment in the enclosure;

connecting the linear array of LED devices to be operable to emit light; and

filling the enclosure with an optically transmissive, fluid medium so that the optically transmissive, fluid medium permeates the color mixing treatment and is in thermal communication with the linear array of LED devices.

12. The method of claim 11 wherein the linear array of LED devices emits light in a substantially omnidirectional pattern.

13. The method of claim 12 wherein the optically transmissive, fluid medium is selected from a group consisting of a liquid and a gel.

14. The method of claim 13 wherein the optically transmissive, fluid medium is an index matching medium.

15. The method of claim 14 further comprising connecting a power supply to the linear array of LED devices.

16. The method of claim 15 wherein the color mixing treatment is selected from a group consisting of an open cell foam and a nanowire.

17. The method of claim 15 further comprising adding a phosphor to the lamp wherein the phosphor is disposed to be energized by the linear array of LED devices.

18. A lamp comprising:

a tubular enclosure having an electrical connection;

an array of LED devices disposed on a metal wire frame in the tubular enclosure to be operable to emit light when energized through the electrical connection; and

an optically transmissive, fluid medium contained in the tubular enclosure in thermal communication with the array of LED devices.

19. The lamp of claim 18 wherein the array of LED devices emits light in a substantially omnidirectional pattern.

20. The lamp of claim 19 wherein the optically transmissive, fluid medium is selected from a group consisting of a liquid and a gel.

21. The lamp of claim 20 wherein the optically transmissive, fluid medium is an index matching medium.

22. The lamp of claim 21 further comprising a color mixing treatment.

23. The lamp of claim 22 wherein the color mixing treatment is selected from a group consisting of an open cell foam and a nanowire, in either case permeated with the index matching medium.

24. The lamp of claim 21 further comprising a power supply coupled to the electrical connection.

25. The lamp of claim 24 wherein the array of LED devices further comprises a plurality of LEDs wherein each LED includes an optically transmissive substrate.

26. The lamp of claim 25 wherein the optically transmissive substrate is selected from a group consisting of sapphire and silicon carbide.

27. The lamp of claim 26 further comprising a color mixing treatment.

28. The lamp of claim 27 wherein the color mixing treatment is selected from a group consisting of an open cell foam and a nanowire, in either case permeated with the index matching medium.

29. The lamp of claim 24 further comprising a phosphor disposed to be energized by the array of LED devices.

30. A lamp comprising:

an enclosure having an electrical connection;

an array of LED devices disposed in the enclosure, the LED devices being electrically connected to be operable to emit light when energized through the electrical connection but otherwise unattached to any separate structure; and

an optically transmissive, fluid medium contained in the enclosure to mechanically support the array of LED devices while in thermal communication with the array of LED devices.

31. The lamp of claim 30 wherein the array of LED devices emits light in a substantially omnidirectional pattern.

32. The lamp of claim 31 wherein the optically transmissive, fluid medium is selected from a group consisting of a liquid and a gel.

33. The lamp of claim 32 wherein the optically transmissive, fluid medium is an index matching medium.

34. The lamp of claim 33 further comprising a color mixing treatment.

35. The lamp of claim 34 wherein the color mixing treatment is selected from a group consisting of an open cell foam and a nanowire, in either case permeated with the index matching medium.

36. The lamp of claim 33 further comprising a power supply coupled to the electrical connection.

37. The lamp of claim 36 wherein the array of LED devices further comprises a plurality of LEDs wherein each LED includes an optically transmissive substrate.

38. The lamp of claim 37 wherein the optically transmissive substrate is selected from a group consisting of sapphire and silicon carbide.

39. The lamp of claim 38 further comprising a color mixing treatment.

40. The lamp of claim 39 wherein the color mixing treatment is selected from a group consisting of an open cell foam and a nanowire, in either case permeated with the index matching medium.

41. The lamp of claim 36 further comprising a phosphor disposed to be energized by the array of LED devices.

42. A lamp comprising:

an enclosure having an electrical connection;

an array of LED devices disposed in the enclosure to be operable to emit light in a substantially omnidirectional 360-degree pattern when the lamp is energized through the electrical connection; and

an optically transmissive, fluid medium contained in the enclosure in thermal communication with the array of LED devices.

43. The lamp of claim 42 wherein the optically transmissive, fluid medium is selected from a group consisting of a liquid and a gel.

44. The lamp of claim 43 wherein the optically transmissive, fluid medium is an index matching medium.

45. The lamp of claim 44 further comprising a color mixing treatment.

46. The lamp of claim 45 wherein the color mixing treatment is selected from a group consisting of an open cell foam and a nanowire, in either case permeated with the index matching medium.

47. The lamp of claim 44 further comprising a power supply coupled to the electrical connection.

48. The lamp of claim 47 wherein the array of LED devices further comprises a plurality of LEDs wherein each LED includes an optically transmissive substrate.

49. The lamp of claim 48 wherein the optically transmissive substrate is selected from a group consisting of sapphire and silicon carbide.

50. The lamp of claim 46 further comprising a color mixing treatment.

51. The lamp of claim 50 wherein the color mixing treatment is selected from a group consisting of an open cell foam and a nanowire, in either case permeated with the index matching medium.

52. The lamp of claim 47 further comprising a phosphor disposed to be energized by the array of LED devices.