LED lighting using spectral notching

• US 9,335,531 B2
• Filed: 12/30/2011
• Issued: 05/10/2016
• Est. Priority Date: 12/30/2011
• Status: Active Grant

• Current Assignee: IDEAL Industries Lighting, LLC (Ideal Industries Incorporated)
• Original Assignee: CREE Incorporated (Wolfspeed, Inc.)
• Inventors: Athalye, Praneet, Negley, Gerald H., van de Ven, Antony Paul
• Primary Examiner(s): Neils, Peggy
• Assistant Examiner(s): GARLEN, ALEXANDER K
• Application Number:
  US13/341,337
• Publication Number:
  US 20130170199A1
• Time in Patent Office: 1,593 Days
• Field of Search: 362/2, 362/84, 362/166, 362/293, 362/311.02, 362/510, 362/800, 257/98, 257/100
• US Class Current: 1/1
• 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 9/64 using wavelength conversion means distinct or spaced from the light-generating element, e.g. a remote phosphor layer
• CPC Class Codes: F21V 13/14 the elements being filters or photoluminescent elements, reflectors and refractors
• CPC Class Codes: F21V 29/87 Organic material, e.g. filled polymer composites; Thermo-conductive additives or coatings therefor
• CPC Class Codes: F21V 29/89 Metals
• CPC Class Codes: F21V 3/04 characterised by materials, surface treatments or coatings
• CPC Class Codes: F21V 3/061 the material being glass
• CPC Class Codes: F21V 3/062 the material being plastics
• CPC Class Codes: F21V 3/12 the coatings comprising photoluminescent substances
• CPC Class Codes: F21V 7/005 with an elongated shape to cooperate with linear light sources
• CPC Class Codes: F21V 7/06 with parabolic curvature
• CPC Class Codes: F21V 7/22 characterised by materials, surface treatments or coatings, e.g. dichroic reflectors
• CPC Class Codes: F21V 9/38 Combination of two or more photoluminescent elements of different materials
• CPC Class Codes: F21V 9/45 by adjustment of photoluminescent elements
• CPC Class Codes: F21Y 2115/10 Light-emitting diodes [LED]
• CPC Class Codes: G02B 19/0009 having refractive surfaces only
• CPC Class Codes: G02B 19/0028 refractive and reflective surfaces, e.g. non-imaging catadioptric systems
• CPC Class Codes: G02B 19/0061 the light source comprising a LED semiconductor devices with at least one potential-jump barrier or surface barrier specially adapted for light emission H01L33/00
• CPC Class Codes: G02B 19/0066 in the form of an LED array
• CPC Class Codes: G02B 5/20 Filters polarising elements G02B5/30
• CPC Class Codes: G02B 5/223 : containing organic substances, e.g. dyes, inks or pigments
• CPC Class Codes: G02B 5/28 : Interference filters
• CPC Class Codes: H01L 2224/48091 : Arched
• CPC Class Codes: H01L 2224/48137 : the bodies being arranged next to each other, e.g. on a common substrate
• CPC Class Codes: H01L 25/0753 : the devices being arranged next to each other
• CPC Class Codes: H01L 2924/00 : Indexing scheme for arrangements or methods for connecting or disconnecting semiconductor or solid-state bodies as covered by H01L24/00
• 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: H01L 2924/1305 : Bipolar Junction Transistor [BJT]
• CPC Class Codes: H01L 33/58 : Optical field-shaping elements
• CPC Class Codes: Y10T 29/49002 : Electrical device making

Abstract

LED lighting using optical elements with spectral notching is disclosed. Embodiments of the invention provide an optical element and LED devices and systems using such an optical element, where spectral notch filtering introduced by the optical element improves the color rendering index (CRI) of emitted light. In some embodiments of the invention, the optical element is made to act as a notch filter by including a rare earth compound such as neodymium oxide in or on the material of which the optical element is made. A color pigment can also be used to impart notch-filtering properties to an optical element. An optical interference film can also be used. The optical element may be included in an LED device such as a multichip component or may be used as an enclosure or reflector for an LED lighting system such as a lamp or fixture.

Claims

1. A LED lighting apparatus comprising:

a base including multiple electrical contacts;

a LED device including a submount, at least one LED arranged on or over the submount, and a lens arranged to transmit light emitted by the at least one LED, the LED device emitting visible light;

a body arranged between the base and the LED device;

a light-transmissive optical enclosure including an edge arranged proximate to the body, including a distal end arranged distal from the body, and defining an interior containing the LED device, wherein the optical enclosure is remotely located from the LED device, and the submount is arranged at an elevated position within the interior between the edge and the distal end,

the LED lighting apparatus is embodied in a LED light bulb, wherein the optical enclosure is arranged along an external surface of the LED light bulb; and

the optical enclosure comprises a notch filtering material configured to receive at least some light generated by the LED device to cause emissions of the LED light bulb to exhibit a spectral notch with a portion of the visible spectrum after being affected by the notch filtering material.

2. The LED lighting apparatus of claim 1, wherein the spectral notch occurs between the wavelengths of 520 nm and 605 nm.

3. The LED lighting apparatus of claim 1, wherein the spectral notch occurs between the wavelengths of 565 nm and 600 nm.

4. The LED lighting apparatus of claim 1, wherein the spectral notch occurs between the wavelengths of 570 nm and 595 nm.

5. The LED lighting apparatus of claim 1, wherein the notch filtering material comprises a rare earth compound.

6. The LED lighting apparatus of claim 1, wherein light emitted from the LED light bulb exhibits a color rendering index (CRI) of at least 84.

7. The LED lighting apparatus of claim 6, wherein the light emitted from the LED light bulb exhibits a CRI of at least 89.

8. A method of assembling a LED lighting apparatus according to claim 1 wherein the at least one LED comprises a plurality of LED chips, the method comprising:

selecting the plurality of LED chips based on desired light output characteristics;

interconnecting the plurality of LED chips; and

positioning the optical enclosure to affect light emitted by the plurality of LED chips, wherein the optical enclosure filters the light emitted by the plurality of LED chips to exhibit a spectral notch.

9. The method of claim 8 further comprising adding a color pigment other than a rare earth compound to at least one of glass, plastic, and silicone to produce the optical enclosure.

10. The method of claim 8 further comprising adding phosphor material to receive at least a portion of emissions of at least some LED chips of the plurality of LED chips.

11. The method of claim 8 wherein the optical enclosure comprises at least one of glass, plastic, and silicone, and the method comprises adding at least one of (i) a color pigment other than a rare earth compound or (ii) a rare earth compound to the at least one of glass, plastic, and silicone.

12. The method of claim 11 wherein the method comprises adding a rare earth compound to the at least one of glass, plastic and silicon, and the rare earth compound comprises at least one of neodymium oxide, didymium, dysprosium, erbium, holmium, praseodymium, and thulium.

13. The method of claim 12, further comprising placing an optically transmissive fluid medium comprising a liquid in the optical enclosure so as to be thermally coupled to the plurality of LED chips, wherein the liquid remains in a liquid state when the plurality of LED chips is operated to aid in cooling the plurality of LED chips.

14. The LED lighting apparatus of claim 1, wherein light intensity is comparatively reduced by the optical enclosure within a predetermined portion of a visible spectrum of light generated by the at least one LED.

15. The LED lighting apparatus of claim 14, further comprising at least one phosphor, and wherein the light generated by the at least one LED includes emissions of the at least one LED in combination with emissions of the at least one phosphor.

16. The LED lighting apparatus of claim 15, wherein the light intensity is comparatively reduced by a peak amount of about 75%.

17. The LED lighting apparatus of claim 15, wherein the light intensity is comparatively reduced by a peak amount of about 50%.

18. The LED lighting apparatus of claim 15, wherein the light intensity is comparatively reduced by a peak amount of between 5% and about 100%.

19. The LED lighting apparatus of claim 18, wherein a full width of the spectral notch corresponding to the comparative reduction at half maximum intensity is about 10 nm and wherein a color rendering index (CRI) of emissions of the LED light bulb is at least about 84.

20. The LED lighting apparatus of claim 19, wherein a center wavelength for the spectral notch is between 580 and 600 nm.

21. The LED lighting apparatus of claim 18, wherein a full width of the spectral notch corresponding to the comparative reduction at half maximum intensity is about 20 nm and wherein a color rendering index (CRI) of emissions of the LED light bulb is at least about 91.

22. The LED lighting apparatus of claim 21, wherein a center wavelength for the spectral notch is between 580 and 600 nm.

23. The LED lighting apparatus of claim 18, wherein a full width of the spectral notch corresponding to the comparative reduction at half maximum is between 10 nm and 20 nm and a center wavelength for the spectral notch is between about 520 nm and about 605 nm.

24. The LED lighting apparatus of claim 23, wherein the spectral notch exhibits a predetermined shape profile.

25. The LED lighting apparatus of claim 23, wherein the notch filtering material comprises a rare earth compound.

26. The LED lighting apparatus of claim 23, wherein the notch filtering material comprises a color pigment other than a rare earth compound to produce the spectral notch.

27. The LED lighting apparatus of claim 23, further comprising a reflector including a reflective material coated with an optical interference film.

28. A method of operating a LED lighting apparatus according to claim 1, the method comprising:

energizing the at least one LED; and

utilizing the optical enclosure to filter a visible light intensity so that the visible light intensity is comparatively reduced within a predetermined part of a spectrum of visible light and color rendering index (CRI) is improved.

29. The method of claim 28 wherein the CRI is improved by at least four points relative to a LED light bulb lacking an optical enclosure arranged to filter light emissions to produce the spectral notch.

30. The method of claim 29 wherein the visible light intensity is comparatively reduced by a peak amount between 25% and about 100%.

31. The method of claim 29 wherein the filtering of the visible light intensity comprises applying a spectral notch with at least one predetermined characteristic.

32. The method of claim 31 wherein the at least one predetermined characteristic comprises at least one of depth, width and shape profile.

33. The method of claim 29 wherein the filtering of the visible light intensity comprises passing light through the optical enclosure.

34. The method of claim 28 wherein the notch filtering material comprises a color pigment other than a rare earth compound to produce the spectral notch.

35. The LED lighting apparatus of claim 1, further comprising a circuit board to which are mounted driver components arranged to supply power to the LED device, wherein the LED device and the driver components are mounted to the circuit board, and wherein the driver components include at least one of a current control circuit, an energy storage element, a voltage control circuit, a rectifier circuit, and a current diversion circuit.

36. The LED lighting apparatus of claim 1, wherein the body comprises a heatsink, and the LED device is in conductive thermal communication with the heatsink.

37. The LED lighting apparatus of claim 1, wherein the base comprises a threaded Edison base.

38. The LED lighting apparatus of claim 1, wherein the optical enclosure comprises a curved globe including a maximum width at a position intermediately arranged between the edge and the distal end, and including a reduced width at the edge.

39. The LED lighting apparatus of claim 36, wherein the edge comprises a lip, and the lip is arranged in or on the heatsink.

40. A LED light bulb comprising:

a base including multiple electrical contacts;

a plurality of interconnected LED chips;

an optical enclosure arranged along an external surface of the LED light bulb, wherein the optical enclosure is remotely located from the plurality of interconnected LED chips and defines an interior containing the plurality of interconnected LED chips;

a circuit board including driver components arranged to supply power to the plurality of interconnected LED chips, wherein the driver components include at least one of a current control circuit, an energy storage element, a voltage control circuit, a rectifier circuit, and a current diversion circuit; and

at least one lens arranged to cover each LED of the plurality of interconnected LED chips, the interior of the optical enclosure containing an optically transmissive fluid medium comprising a liquid that is thermally coupled to the plurality of interconnected LED chips, the at least one lens being arranged between the plurality of interconnected LED chips and the fluid medium, with the liquid remaining in a liquid state when the plurality of interconnected LED chips are operated to aid in cooling the plurality of interconnected LED chips;

wherein the optical enclosure comprises a notch filtering material and is transmissive of at least a portion of light emitted by the plurality of interconnected LED chips while filtering the light to exhibit a spectral notch.

41. The LED light bulb of claim 40 wherein the spectral notch occurs between the wavelengths of 520 nm and 605 nm.

42. The LED light bulb of claim 41 wherein the spectral notch occurs between the wavelengths of 565 nm and 600 nm.

43. The LED light bulb of claim 42 wherein the spectral notch occurs between the wavelengths of 570 nm and 595 nm.

44. The LED light bulb of claim 40 wherein the optical enclosure comprises a rare earth compound.

45. The LED light bulb of claim 40 further comprising phosphor associated with at least one LED chip of the plurality of interconnected LED chips.

46. The LED light bulb of claim 45 wherein the light emitted by the LED light bulb exhibits a color-rendering index (CRI) of at least 84.

47. The LED light bulb of claim 46 wherein the light emitted by the LED light bulb exhibits a CRI of at least 89.

48. An LED lighting system comprising:

an LED array operable to emit light when energized through an electrical connection;

an optical element that filters the light to exhibit a spectral notch after being affected by the optical element;

a power supply connected to the LED array through the electrical connection; and

at least one lens arranged to cover each LED of the LED array;

wherein the optical element comprises an optical enclosure containing an optically transmissive fluid medium comprising a liquid that is thermally coupled to the LED array, the at least one lens is arranged between the LED array and the fluid medium, and the liquid remains in a liquid state when the LED array is operated to aid in cooling LED chips of the LED array.

49. The LED lighting system of claim 48 wherein the spectral notch occurs between the wavelengths of 520 nm and 605 nm.

50. The LED lighting system of claim 49 wherein the spectral notch occurs between the wavelengths of 565 nm and 600 nm.

51. The LED lighting system of claim 50 wherein the spectral notch occurs between the wavelengths of 570 nm and 595 nm.

52. The LED lighting system of claim 48 wherein the optical element comprises a color pigment other than a rare earth compound to produce the spectral notch.

53. The LED lighting system of claim 48 wherein the optical element further comprises a rare earth compound.

54. The LED lighting system of claim 48 wherein the optical enclosure contains the LED array, and wherein the optical enclosure embodies an external enclosure of a light bulb.

55. The LED lighting system of claim 54 wherein the light from the LED lighting system exhibits a color-rendering index (CRI) of at least 84.

56. The LED lighting system of claim 55 wherein the light from the LED lighting system exhibits a CRI of at least 89.

57. A LED lighting apparatus comprising:

a plurality of LED packages arranged on a mounting surface in conductive thermal communication with at least one heatsink, each LED package of the plurality of LED packages including at least one LED and a lens arranged to transmit light emitted by the at least one LED, the LED packages emitting visible light;

the LED lighting apparatus is embodied in a troffer-type LED ceiling fixture; and

the at least one heatsink is arranged to dissipate heat to an environment proximate to the troffer-type LED ceiling fixture;

wherein the LED lighting apparatus comprises at least one of the following features (a) or (b);

(a) a reflector spatially separated from the plurality of LED packages, the reflector comprising a reflective material coated with a notch filtering material configured to receive at least some light generated by the plurality of LED packages to cause emissions of the troffer-type LED ceiling fixture to exhibit a spectral notch within a portion of the visible spectrum after being affected by the notch filtering material;

or

(b) at least one lens plate spatially separated from the plurality of LED packages, the at least one lens plate comprising a light transmissive material and a notch filtering material configured to receive at least some light produced by the plurality of LED packages to cause emissions of the troffer-type LED ceiling fixture to exhibit a spectral notch within a portion of the visible spectrum after being affected by the notch filtering material.

58. The LED lighting apparatus of claim 57, wherein each LED package of the plurality of LED packages includes a submount supported by the mounting surface, and the at least one LED of each LED package is arranged on or over the submount.

59. The LED lighting apparatus of claim 57, comprising a reflector spatially separated from the plurality of LED packages, the reflector comprising a reflective material coated with a notch filtering material configured to receive at least some light generated by the plurality of LED packages to cause emissions of the troffer-type LED ceiling fixture to exhibit a spectral notch after being affected by the notch filtering material.

60. The LED lighting apparatus of claim 57, comprising at least one lens plate spatially separated from the plurality of LED packages, the at least one lens plate comprising a light transmissive material and a notch filtering material configured to receive at least some light produced by the plurality of LED packages to cause emissions of the troffer-type LED ceiling fixture to exhibit a spectral notch after being affected by the notch filtering material.

61. The LED lighting apparatus of claim 57, wherein the notch filtering material comprises an optical interference film to produce the spectral notch.