Lighting device with flexibly coupled heatsinks

• US 9,395,057 B2
• Filed: 02/07/2011
• Issued: 07/19/2016
• Est. Priority Date: 02/07/2011
• Status: Active Grant

• Current Assignee: Creeled Incorporated
• Original Assignee: CREE Incorporated (Wolfspeed, Inc.)
• Inventors: van de Ven, Antony Paul
• Primary Examiner(s): Mai, Anh
• Assistant Examiner(s): FAROKHROOZ, FATIMA N
• Application Number:
  US13/022,542
• Publication Number:
  US 20120201024A1
• Time in Patent Office: 1,989 Days
• Field of Search: 362/580, 362/565, 362/218, 362/219, 362/373, 362/225, 362/227, 36224901-24908, 362/249.13, 362/268, 362/294, 362/367, 362/547, 362/555, 439/487, 313/17, 313/22, 313/33, 313/46, 313/45, 257/81
• US Class Current: 1/1
• CPC Class Codes: F21S 2/005 of modular construction
• CPC Class Codes: F21S 4/26 of rope form, e.g. LED lighting ropes, or of tubular form
• CPC Class Codes: F21V 19/0015 Fastening arrangements intended to retain light sources
• CPC Class Codes: F21V 23/002 Arrangements of cables or conductors inside a lighting device, e.g. means for guiding along parts of the housing or in a pivoting arm
• CPC Class Codes: F21V 29/74 with fins or blades
• CPC Class Codes: F21Y 2115/10 Light-emitting diodes [LED]
• CPC Class Codes: H01L 2224/48091 Arched
• CPC Class Codes: H01L 2924/00014 the subject-matter covered by the group, the symbol of which is combined with the symbol of this group, being disclosed without further technical details
• CPC Class Codes: Y10T 29/49117 Conductor or circuit manufacturing

Abstract

Lighting devices include multiple heatsink elements arranged to dissipate heat generated by the multiple solid state emitters, with non-rigid coupling between heatsink elements. At least a portion of each heatsink element is preferably exposed to an ambient environment. Each heatsink element may include a switching element, may be addressable, and may receive wired or wireless control signals. A modular solid state lighting unit includes a heatsink and at least one solid state light emitter, with at least one flexible element secured to the heatsink element and to multiple electrical couplings. Flexible rope lights and two-dimensional arrays of emitters are provided.

Claims

1. A solid state lighting device comprising:

multiple solid state emitters; and

multiple heatsink elements arranged to dissipate heat generated by the multiple solid state emitters;

wherein each heatsink element of the multiple heatsink elements is substantially rigid and is coupled to at least one other heatsink element of the multiple heatsink elements solely via a non-rigid connection;

wherein a portion of each heatsink element of the multiple heatsink elements is exposed to an ambient air environment; and

wherein the solid state lighting device comprises at least one of the following features (A) or (B);

(A) the non-rigid connection comprises an electrical conductor and a tubular flexible protective covering element that comprises a light-transmissive material and extends in a longitudinal direction over an entirety of each solid state emitter of the multiple solid state emitters and extends over a first portion of each heatsink element of the multiple heatsink elements, wherein a second portion of each heatsink element of the multiple heatsink elements is not covered with the tubular flexible protective covering element;

or

(B) the non-rigid connection comprises an electrical conductor and a flexible tube that comprises a light-transmissive material and extends in a longitudinal direction over an entirety of each solid state emitter of the multiple solid state emitters.

2. The solid state lighting device of claim 1, wherein at least a portion of each heatsink element of the multiple heatsink elements is substantially rigid.

3. The solid state lighting device of claim 1, wherein the non-rigid connection comprises an electrical conductor and a tubular flexible protective covering element that comprises a light-transmissive material and extends in a longitudinal direction over an entirety of each solid state emitter of the multiple solid state emitters and a first portion of each heatsink element of the multiple heatsink elements, wherein a second portion of each heatsink element of the multiple heatsink elements is not covered with the tubular flexible protective covering element.

4. The solid state lighting device of claim 3, wherein the second portion of each heatsink element of the multiple heatsink elements protrudes in a lateral direction through the tubular flexible protective covering element.

5. The solid state lighting device of claim 1, wherein each heatsink element of the multiple heatsink elements is spaced apart from each other heatsink element.

6. The solid state lighting device of claim 1, wherein each heatsink element of the multiple heatsink elements comprises stamped metal with an electrically insulating material arranged on at least a portion of at least one surface of the heatsink element.

7. The solid state lighting device of claim 1, wherein at least a portion of each heatsink element of the multiple heatsink elements comprises a printed circuit board, and wherein at least a portion of the printed circuit board is exposed to the ambient air environment.

8. The solid state lighting device of claim 1, wherein each heatsink element of the multiple heatsink elements is not in substantial conductive thermal communication with any other heatsink element of the multiple heatsink elements.

9. The solid state lighting device of claim 1, wherein at least some solid state emitters of the multiple solid state emitters are adapted to output emissions perceived as white.

10. The solid state lighting device of claim 1, wherein the multiple solid state emitters include at least two solid state emitters with peak emissions at wavelengths at least about 50 nm apart.

11. The solid state lighting device of claim 1, wherein each heatsink element of the multiple heatsink elements is in conductive thermal communication with at least two solid state emitters of the multiple solid state emitters.

12. The solid state lighting device of claim 11, wherein the at least two solid state emitters are independently controllable.

13. The solid state lighting device of claim 1, wherein the multiple solid state emitters include solid state emitters facing in different directions when the multiple heatsink elements are arranged in a straight line.

14. The solid state lighting device of claim 1, further comprising at least one electrical cable extending between the multiple heatsink elements.

15. The solid state lighting device of claim 1, wherein each heatsink element of the multiple heatsink elements is electrically isolated from the multiple solid state emitters.

16. The solid state lighting device of claim 1, wherein each heatsink element of the multiple heatsink elements comprises at least one electrically conductive trace in electrical communication with at least one solid state emitter supported by the heatsink element.

17. The solid state lighting device of claim 1, comprising at least one spacer element arranged to maintain separation between at least two heatsink elements of the multiple heatsink elements.

18. The solid state lighting device of claim 1, further comprising at least one lumiphor arranged to receive emissions from at least one solid state emitter of the multiple solid state emitters.

19. The solid state lighting device of claim 1, wherein each heatsink element of the multiple heatsink elements is sized and arranged to dissipate at least about 2 watts to the ambient air environment while maintaining a junction temperature of at least one solid state emitter of the multiple solid state emitters arranged in conductive thermal communication with the heatsink element at or below 85°

C.

20. The solid state lighting device of claim 1, wherein:

the multiple solid state emitters are contained in multiple solid state emitter packages each including at least two solid state emitters and at least one of the following features (a) to (c);

(a) a single leadframe including multiple conductive leads arranged to supply current to the at least two solid state emitters;

(b) a single substrate arranged to structurally support the at least two solid state emitters;

or (c) a single reflector arranged to reflect light emissions of each solid state emitter of the at least two solid state emitters; and

each heatsink element of the multiple heatsink elements is arranged to support at least one solid state emitter package of the multiple solid state emitter packages.

21. The solid state lighting device of claim 1, operatively connected to at least one sensor, wherein operation of the solid state lighting device is controlled responsive to an output signal of the at least one sensor.

22. The solid state lighting device of claim 1, having a luminous efficiency of at least about 100 lumens per watt.

23. The solid state lighting device of claim 22, having a color rendering index of at least 90.

24. The solid state lighting device of claim 1, further comprising a diffuser arranged to receive and diffuse emissions from the multiple solid state emitters.

25. The solid state lighting device of claim 1, wherein the non-rigid connection comprises an electrical conductor and a flexible tube that comprises a light-transmissive material and extends in a longitudinal direction over an entirety of each solid state emitter of the multiple solid state emitters.

26. The solid state lighting device of claim 1, wherein the tubular flexible protective covering element or the flexible tube comprises a material molded over or around a portion of each heatsink element of the multiple heatsink elements.

27. The solid state lighting device of claim 1, wherein each heatsink element of the multiple heatsink elements is arranged to dissipate heat generated by at least one solid state emitter of the multiple solid state emitters through a thermally conductive path devoid of an electrical lead for the at least one solid state emitter.

28. The solid state lighting device of claim 1, embodied in a rope light.

29. The solid state lighting device of claim 1, wherein the multiple heatsink elements are arranged in a two-dimensional array.

30. The solid state lighting device of claim 29, further comprising at least one control element arranged to individually control each solid state emitter of the multiple solid state emitters.

31. The solid state lighting device of claim 1, further comprising multiple switching elements arranged to selectively operate the multiple solid state emitters.

32. The solid state lighting device of claim 31, wherein each switching element of the multiple switching elements is individually addressable.

33. The solid state lighting device of claim 31, wherein each switching element of the multiple switching elements has an associated wireless signal receiver to permit wireless control of the multiple switching elements.

34. The solid state lighting device of claim 31, further comprising a controller operatively arranged to control the multiple switching elements.

35. A method for fabricating a solid state lighting device according to claim 1, the method comprising mounting multiple solid state emitters in conductive thermal communication with multiple heatsink elements arranged to dissipate heat generated by the multiple solid state emitters wherein a portion of each heatsink element of the multiple heatsink elements is exposed to an ambient air environment, and coupling each heatsink element via the non-rigid connection with at least one other heatsink element of the multiple heatsink elements.

36. The method of claim 35, wherein at least a portion of each heatsink element of the multiple heatsink elements is substantially rigid.

37. The method of claim 35, further comprising fabricating the multiple heatsink elements including a step of stamping said multiple heatsink elements from at least one metal-containing sheet.

38. The method of claim 37, wherein fabricating the multiple heatsink elements includes forming at least one electrical trace in or on at least one surface of each heatsink element of the multiple heatsink elements.

39. The method of claim 37, further comprising bending at least a portion of each heatsink element into a non-planar configuration.

40. The method of claim 35, further comprising forming a tubular flexible protective covering element extending in a longitudinal direction over the multiple solid state emitters and a first portion of each heatsink element of the multiple heatsink elements, wherein a second portion of each heatsink element of the multiple heatsink elements is not covered with the tubular flexible protective covering element.

41. The method of claim 35, wherein at least a portion of each heatsink element of the multiple heatsink elements comprises a printed circuit board, wherein at least a portion of the printed circuit board is exposed to an ambient air environment.

42. The method of claim 35, wherein the non-rigid connection comprises a flexible tube.