LIGHTING SYSTEM USING SEMICONDUCTOR COUPLED WITH A REFLECTOR HAVE A REFLECTIVE SURFACE WITH A PHOSPHOR MATERIAL

• US 20080291670A1
• Filed: 10/31/2006
• Published: 11/27/2008
• Est. Priority Date: 09/29/2004
• Status: Active Grant

• Current Assignee: ABL IP Holding LLC (Acuity Brands, Inc.)
• Original Assignee: Advanced Optical Technologies, LLC
• Inventors: Rains, Jack C.
• Granted Patent: US 7,828,459 B2
• Time in Patent Office: Days
• US Class Current: 362/231
• CPC Class Codes: F21K 9/62 using mixing chambers, e.g. housings with reflective walls
• 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: F21S 41/37 characterised by their material, surface treatment or coatings
• CPC Class Codes: F21V 7/0008 providing for indirect lighting
• CPC Class Codes: F21V 7/0025 Combination of two or more reflectors for a single light source array of reflectors for a cluster of light sources F21V7/0083
• CPC Class Codes: F21V 7/26 the material comprising photoluminescent substances
• CPC Class Codes: F21V 7/30 the coatings comprising photoluminescent substances
• CPC Class Codes: F21V 9/08 for producing coloured light, e.g. monochromatic; for reducing intensity of light with provision for controlling the colour F21V9/40
• CPC Class Codes: F21Y 2115/10 Light-emitting diodes [LED]
• CPC Class Codes: H01L 2224/48091 Arched
• CPC Class Codes: H01L 2224/48247 connecting the wire to a bond pad of the item
• CPC Class Codes: H01L 2924/00012 Relevant to the scope of the group, the symbol of which is combined with the symbol of this group
• 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 2924/181 Encapsulation
• CPC Class Codes: H05B 45/20 Controlling the colour of the light

Abstract

To improve semiconductor-based systems for generating white light, a phosphor is integrated with an external structure, such as a reflector. A disclosed exemplary system, for illumination applications, utilizes one or more semiconductor devices for emitting radiant energy of a first wavelength. A reflector outside the package of the LED or other semiconductor device has a reflective surface arranged to receive radiant energy from the energy source. At least some of the received radiant energy of the first wavelength excites one or more phosphors associated with an external light processing element, for example, located along the surface of the reflector, to emit light, including visible light energy of at least one second wavelength different from the first wavelength. In the examples, at least some of visible light emitted by the phosphor is reflected by the reflective surface of the reflector and directed to facilitate the particular humanly perceptible luminance or illumination application.

Claims

1-34. -34. (canceled)

35. A semiconductor lighting system, for a visible light illumination application in a region or area to be inhabited by a person, the lighting system comprising:

a semiconductor device, for emitting radiant energy of a first wavelength;

a reflector outside a package of the semiconductor device, having a reflective surface arranged to receive radiant energy from the semiconductor device, wherein the reflective surface exhibits a diffuse reflectivity and forms an optical integrating cavity with an optical aperture for emission of combined radiant energy;

at least one phosphor extending over at least a substantial portion of the reflective surface of the reflector, such that radiant energy of the first wavelength from the semiconductor device excites the at least one phosphor to emit visible light, comprising visible light energy of at least one second wavelength different from the first wavelength, wherein at least some of visible light emitted by the at least one phosphor is reflected by the reflective surface of the reflector; and

a deflector having an inner reflective surface coupled to the optical aperture of the optical integrating cavity,

wherein the lighting system directs at least the visible light emitted by the at least one phosphor so that it can be perceived by a person when present in the region or area to be inhabited.

36. The lighting system of claim 35, wherein the semiconductor device comprises a light emitting diode for emitting at least some ultraviolet (UV) radiation.

37. The lighting system of claim 35, wherein the semiconductor device comprises at least one light emitting diode for emitting at least some blue light.

38. The lighting system of claim 35, wherein:

the semiconductor device emits blue light; and

the system further comprises at least one semiconductor device for emitting visible red light and at least one semiconductor device for emitting green light arranged to emit at least some visible red light and green light for reflection from the reflective surface of the reflector.

39. The lighting system of claim 35, wherein:

the semiconductor device emits ultraviolet (UV) radiant energy; and

the system further comprises at least one semiconductor device for emitting visible red light, at least one semiconductor device for emitting green light and at least one semiconductor device for emitting blue light arranged to emit at least some visible red, green and blue light for reflection from the reflective surface of the reflector.

64. The lighting system of claim 35, wherein the at least one phosphor comprises quantum dots.

40. A semiconductor lighting system, for a visible light illumination application in a region or area to be inhabited by a person, the lighting system comprising:

a semiconductor device, for emitting radiant energy of a first wavelength;

a reflector outside a package of the semiconductor device, having a reflective surface arranged to receive radiant energy from the energy source package; and

at least one phosphor extending over at least a substantial portion of the reflective surface of the reflector, such that radiant energy of the first wavelength from the semiconductor device excites the at least one phosphor to emit visible light, comprising visible light energy of at least one second wavelength different from the first wavelength,

wherein;

at least some of visible light emitted by the at least one phosphor is reflected by the reflective surface of the reflector, and the lighting system directs at least the visible light emitted by the at least one phosphor so that it can be perceived by a person when present in the region or area to be inhabited;

the reflective surface exhibits a diffuse reflectivity;

the reflective surface forms a diffusely reflective cavity having an optical aperture; and

the lighting system further comprises a mask outside the cavity, having a reflective surface facing toward the optical aperture of the cavity and arranged to occlude a substantial portion of the optical aperture.

65. The lighting system of claim 40, wherein the at least one phosphor comprises quantum dots.

41. A semiconductor lighting system, for a visible light illumination application in a region or area to be inhabited by a person, the lighting system comprising:

a semiconductor device, for emitting radiant energy of a first wavelength;

a reflector outside a package of the semiconductor device, having a reflective surface arranged to receive radiant energy from the semiconductor device;

at least one phosphor extending over at least a substantial portion of the reflective surface of the reflector, such that radiant energy of the first wavelength from the semiconductor device excites the at least one phosphor to emit visible light, comprising visible light energy of at least one second wavelength different from the first wavelength, wherein at least some of visible light emitted by the at least one phosphor is reflected by the reflective surface of the reflector, and the lighting system directs at least the visible light emitted by the at least one phosphor so that it can be perceived by a person when present in the region or area to be inhabited; and

a second reflector positioned between the energy source package and a region to be illuminated by the visible light from the system so as to mask view of the energy source package by the person.

42. The lighting system of claim 41, further comprising at least one second phosphor extending over at least a substantial portion of the reflective surface of the second reflector, such that radiant energy excites the at least one second phosphor to emit visible light, comprising visible light energy of a wavelength different from the first wavelength.

66. The lighting system of claim 41, wherein the at least one phosphor comprises quantum dots.

43. A semiconductor lighting system, for a visible light illumination application in a region or area to be inhabited by a person, the lighting system comprising:

a semiconductor device, for emitting radiant energy of a first wavelength;

a reflector outside a package of the semiconductor device, having a reflective surface arranged to receive radiant energy from the semiconductor device;

at least one phosphor extending over at least a substantial portion of the reflective surface of the reflector, such that radiant energy of the first wavelength from the semiconductor device excites the at least one phosphor to emit visible light, comprising visible light energy of at least one second wavelength different from the first wavelength, wherein;

at least some of visible light emitted by the at least one phosphor is reflected by the reflective surface of the reflector, and the lighting system directs at least the visible light emitted by the at least one phosphor so that it can be perceived by a person when present in the region or area to be inhabited, and

the at least one phosphor doped within the reflector comprises;

a first phosphor of a type which is excited by radiant energy of the first wavelength to emit visible light comprising light energy of the second wavelength; and

a second phosphor of a type different from the first type, which is excited to emit visible light comprising light energy of a third wavelength different from the first and second wavelengths.

44. The lighting system of claim 43, wherein the at least one phosphor doped within the reflector further comprises a third phosphor of a type which is excited to emit visible light comprising light energy of a fourth wavelength different from the first, second and third wavelengths.

45. The lighting system of claim 43, wherein the semiconductor device comprises a semiconductor device for emitting at least some ultraviolet (UV) radiation.

46. The lighting system of claim 43, wherein the semiconductor device comprises a semiconductor device for emitting at least some blue light.

67. The lighting system of claim 43, wherein at least one of the first and second phosphors comprises quantum dots.

47. A semiconductor lighting system, for a visible light illumination application in a region or area to be inhabited by a person, the lighting system comprising:

a structure forming an optical integrating cavity comprising a material forming a diffusely reflective inner surface of the cavity and at least one passage for emission of radiant energy integrated by diffuse reflection within the cavity in a direction to facilitate the light illumination application in the region or area to be inhabited;

at least one light emitting semiconductor device, coupled for emission of radiant energy comprising a first wavelength into the cavity; and

at least one phosphor extending over at least a substantial portion of the diffusely reflective inner surface of the cavity, the at least one phosphor being of a type excited by radiant energy of the first wavelength for emission of visible light of at least one second wavelength different from the first wavelength for reflection and integration within the cavity so as to be included in light emitted through the at least one passage, wherein;

the at least one light emitting semiconductor device comprises a plurality of light emitting diodes (LEDs);

a first one of the LEDs emits radiant energy of a first character; and

a second one of the LEDs emits radiant energy of a second character, different from the first character.

48. The lighting system of claim 47, wherein:

the first light emitting diode (LED) is within an enclosure; and

the reflective inner surface of the cavity is outside the enclosure of the first LED.

49. The lighting system of claim 48, wherein the first LED comprises a white, blue or ultraviolet (UV) LED.

50. The lighting system of claim 47, wherein:

the radiant energy from the first LED comprises light of a first color; and

the radiant energy from the second LED comprises light of a second color different from the first color.

51. The lighting system of claim 50, wherein a third one of the LEDs emits radiant energy comprising light of a third color different from the first and second colors.

52. The lighting system of claim 51, wherein at least two of the colors of light are visible colors.

53. The lighting system of claim 50, wherein the system forms a fixture for illuminating the region or area to be inhabited.

68. The lighting system of claim 47, wherein the at least one phosphor comprises quantum dots.

54. A semiconductor lighting system, for a visible light illumination application in a region or area to be inhabited by a person, the lighting system comprising:

a structure forming an optical integrating cavity comprising a material forming a diffusely reflective inner surface of the cavity and at least one optical passage for emission of radiant energy integrated by diffuse reflection within the cavity in a direction to facilitate the light illumination application in the region or area to be inhabited, wherein;

the structure forming the optical integrating cavity comprises a base with a diffusely reflective surface and a mask with a reflective surface facing toward the diffusely reflective surface of the base, and

at least portions of the reflective surfaces of the base and the mask form the reflective inner surface of the optical integrating cavity;

a light emitting semiconductor device, coupled for emission of radiant energy comprising a first wavelength into the cavity; and

at least one phosphor extending over at least a substantial portion of one or more of the reflective surfaces of the base and the mask, the at least one phosphor being of a type excited by radiant energy of the first wavelength for emission of visible light of at least one second wavelength different from the first wavelength for reflection and integration within the cavity so as to be included in light emitted through the at least one passage.

55. The lighting system of claim 54, wherein the reflective surface of the mask is diffusely reflective.

69. The lighting system of claim 54, wherein the at least one phosphor comprises quantum dots.

56. A semiconductor lighting system, for a visible light illumination application in a region or area to be inhabited by a person, the lighting system comprising:

a structure forming an optical integrating cavity comprising a material forming a diffusely reflective inner surface of the cavity and at least one optical passage for emission of radiant energy integrated by diffuse reflection within the cavity in a direction to facilitate the light illumination application in the region or area to be inhabited;

a light emitting semiconductor device, coupled for emission of radiant energy comprising a first wavelength into the cavity; and

at least one phosphor extending over at least a substantial portion of the diffusely reflective inner surface of the cavity, the at least one phosphor being of a type excited by radiant energy of the first wavelength for emission of visible light of at least one second wavelength different from the first wavelength for reflection and integration within the cavity so as to be included in light emitted through the at least one passage,

wherein the at least one phosphor comprises;

a first phosphor of a type which is excited by radiant energy of the first wavelength to emit visible light comprising the second wavelength; and

a second phosphor of a type different from the first type, which is excited to emit visible light of a third wavelength different from the first and second wavelengths.

57. The lighting system of claim 56, wherein the at least one phosphor comprises a third phosphor of a type which is excited to emit visible light of a fourth wavelength different from the first, second and third wavelengths.

58. The lighting system of claim 56, wherein the light emitting semiconductor device comprises a light emitting diode for emitting at least some ultraviolet (UV) radiation.

59. The lighting system of claim 58, wherein the light emitting semiconductor device comprises a light emitting diode for emitting at least some blue light.

70. The lighting system of claim 56, wherein at least one of the first and second phosphors comprises quantum dots.

60. A light emitting diode (LED) lighting system, comprising:

A) a light fixture for a visible light illumination application in a region or area to be inhabited by a person, the light fixture comprising;

1) an optical integrating cavity having at least one diffusely reflective interior surface and an optical passage;

2) at least one phosphor material extending over at least a substantial portion of the at least one diffusely reflective interior surface of the optical integrating cavity, for converting radiant energy of a first wavelength into visible light comprising visible light energy of at least one second wavelength different from the first wavelength;

3) wherein reflections of visible light from said at least one diffusely reflective surface of the optical integrating cavity one or more times within the cavity optically integrate visible light, including light of the second wavelength from the phosphor material, before emission as the optically integrated light through the optical passage of the integrating cavity in a direction to facilitate said visible light illumination application in the region or area to be inhabited;

B) one or more LEDs each coupled to supply light to the cavity at a point not directly visible through the optical passage and in a direction so as to cause a substantial portion of light supplied by each LED to reflect from said at least one diffusely reflective surface of the optical integrating cavity one or more times without direct emission of the substantial portion through the optical passage, at least one of the one or more LEDs supplying light of the first wavelength to the cavity; and

C) a control circuit coupled to the one or more LEDs, for establishing output intensity of light of the one or more LEDs to set a characteristic of the optically integrated light emitted through the optical passage of the optical integrating cavity.

61. The LED lighting system of claim 60, wherein each of the one or more LEDs is coupled to supply light to the cavity in a direction such that substantially all direct emissions from the one or more LEDs are directed toward and reflect from the at least one diffusely reflective interior surface of the optical integrating cavity without direct emission thereof through the optical passage.

71. The lighting system of claim 60, wherein the at least one phosphor material comprises quantum dots.

62. A light emitting diode (LED) lighting system, comprising:

A) a light fixture for a visible light illumination application in a region or area to be inhabited by a person, the light fixture comprising an optical integrating cavity having at least one diffusely reflective interior surface and an optical passage;

B) one or more LEDs each coupled to supply light to the cavity at a point not directly visible through the optical passage and in a direction so as to cause a substantial portion of light supplied by each LED to reflect from said at least one diffusely reflective surface of the optical integrating cavity one or more times without direct emission of the substantial portion through the optical passage, at least one of the one or more LEDs supplying light of a first wavelength to the cavity, wherein;

reflections of light from said at least one diffusely reflective surface of the optical integrating cavity one or more times within the cavity optically integrate light, before emission as the optically integrated light through the optical passage of the integrating cavity in a direction to facilitate said visible light illumination application in the region or area to be inhabited, and

the fixture further comprises at least one phosphor material associated with a light processing surface of the fixture outside of the LEDs, for converting radiant energy of the first wavelength into visible light comprising visible light energy of at least one second wavelength different from the first wavelength, such that light emissions from the fixture include visible light energy of at the least one second wavelength from the excited at least one phosphor material as well as at least some other optically integrated light from the integrating cavity; and

C) a control circuit coupled to the one or more LEDs, for establishing output intensity of light of the one or more LEDs to set a characteristic of the optically integrated light emitted through the optical passage of the optical integrating cavity.

63. The LED lighting system of claim 62, wherein each of the one or more LEDs is coupled to supply light to the cavity in a direction such that substantially all direct emissions from the one or more LEDs are directed toward and reflect from the at least one diffusely reflective interior surface of the optical integrating cavity without direct emission thereof through the optical passage.

72. The lighting system of claim 62, wherein the at least one phosphor material comprises quantum dots.