Boundary-Mountable Lighting Systems

BACKGROUND OF THE INVENTION
1. Field of the Invention.

The present invention relates to the field of lighting systems that include semiconductor light-emitting devices, and processes related to such lighting systems.

2. Background of the Invention.

Numerous lighting systems that include semiconductor light-emitting devices have been developed. As examples, some of such lighting systems may be suitable for mounting at a boundary such as a wall, ceiling or floor for example, so that light may be emitted by the semiconductor light-emitting devices for propagation away from the boundary. Despite the existence of these lighting systems, further improvements are still needed in lighting systems for mounting at a boundary, and in processes related to such lighting systems.

SUMMARY

In an example of an implementation, a lighting system is provided that includes a visible-light source including a semiconductor light-emitting device, the visible-light source being configured for generating visible-light emissions having a central light emission axis from the semiconductor light-emitting device. In this example, the lighting system may include a pan assembly having a pan ring, a pinion gear, and a central fixed gear. Further in this example of the lighting system, rotating the pinion gear may cause the pan ring to be rotated around a pan axis through a range of rotation around the central fixed gear.

In another example of an implementation, a lighting system is provided that includes a visible-light source including a semiconductor light-emitting device, the visible-light source being configured for generating visible-light emissions having a central light emission axis from the semiconductor light-emitting device. In this example, the lighting system may include a heat-sink being attached to the visible-light source. Further in this example, the lighting system may include a tilt assembly including a tilt adjustment screw, a leadscrew, and two spaced-apart panels each having an arcuate slot, the arcuate slots being mutually concentric and collectively defining an arcuate tilt path, the heat-sink being movably attached to the arcuate slots. Additionally in this example of the lighting system, the tilt adjustment screw may be configured for driving the leadscrew to cause movement of the heat-sink to a selected position along the tilt path; movement of the heat-sink along the tilt path may cause the visible-light source to be moved along the tilt path.

In a further example of an implementation, a lighting system is provided that includes a visible-light source including a semiconductor light-emitting device, the visible-light source being configured for generating visible-light emissions having a central light emission axis from the semiconductor light-emitting device. In this example, the lighting system may include a tilt adjustment screw, a leadscrew, and a universal joint assembly. Further in this example of the lighting system, the universal joint assembly may link together the tilt adjustment screw and the leadscrew. Additionally in this example of the lighting system, the universal joint assembly may include a gimbal and a swing bar having swing arms, the swing bar being in threaded engagement with the leadscrew, the tilt adjustment screw being attached to the gimbal. Also in this example of the lighting system, the swing arms may be connected with the visible-light source. Additionally in this example of the lighting system, the tilt adjustment screw may be configured for causing the universal joint assembly to drive the leadscrew for movement of the visible-light source to a selected position along a tilt path.

In an additional example of an implementation, a lighting system is provided that includes a visible-light source including a semiconductor light-emitting device, the visible-light source being configured for generating visible-light emissions having a central light emission axis from the semiconductor light-emitting device. In this example, the lighting system may include a light emission aperture being configured for causing the visible-light emissions to be emitted from the lighting system; and a heat-sink being attached to the visible-light source. Further in this example, the lighting system may include a support assembly being attached to the heat-sink or to the visible-light source, the support assembly being configured for securing the heat-sink and the visible-light source together at a plurality of selectable distances away from the light emission aperture.

In another example of an implementation, a lighting system is provided that includes a visible-light source including a semiconductor light-emitting device, the visible-light source being configured for generating visible-light emissions having a central light emission axis from the semiconductor light-emitting device, the visible-light source having a thermally-conductive surface. In this example, the lighting system may include a heat-sink having another thermally-conductive surface being configured for being placed in thermally-conductive contact with the thermally-conductive surface of the visible-light source. Additionally in this example of the lighting system, the another thermally-conductive surface of the heat sink may have a Dzus-type fastener button; and the thermally-conductive surface of the visible-light source may have a Dzus-type cavity containing a spring wire. Alternatively in this example of the lighting system, the another thermally-conductive surface of the heat sink may have a Dzus-type cavity containing a spring wire; and the thermally-conductive surface of the visible-light source may have a Dzus-type fastener button. Also in this example of the lighting system, the cavity may be adapted for receiving the fastener button and for rotation of the fastener button within the cavity to cause reversible deformation of the spring wire for reversibly locking together the visible-light source and the heat-sink.

Other systems, processes, features and advantages of the invention will be or will become apparent to one with skill in the art upon examination of the following figures and detailed description. It is intended that all such additional systems, processes, features and advantages be included within this description, be within the scope of the invention, and be protected by the accompanying claims.

BRIEF DESCRIPTION OF THE FIGURES

The invention can be better understood with reference to the following figures. The components in the figures are not necessarily to scale, emphasis instead being placed upon illustrating the principles of the invention. Moreover, in the figures, like reference numerals designate corresponding parts throughout the different views.

Figures LTS1 to LTS37 on sheets 1-37 of the drawings are screenshots of examples [100a-d] of the lighting system.

Figures PAN1 to PAN34 on sheets 38-71 of the drawings are screenshots of Pan-related features of the examples [100a-d] of the lighting system.

Figures TLT1 to TLT32 on sheets 72-103 of the drawings are screenshots of Tilt-related features of the examples [100a-d] of the lighting system.

Figures UJT1 to UJT27 on sheets 104-127 of the drawings are screenshots of Universal Joint-related features of the examples [100a-d] of the lighting system.

Figures ZAD1 to ZAD28 on sheets 128-155 of the drawings are screenshots of Z-Adjustment-related features of the examples [100a-d] of the lighting system.

Figures TWL1 to TWL26 on sheets 156-180 of the drawings are screenshots of Twist-Lock-related features of the examples [100a-d] of the lighting system.

Figures PPS1 to PPS43 on sheets 181-223 of the drawings are screenshots of Pluggable Power Supply-related features of the examples [100a-d] of the lighting system.

Figures WAW1 to WAW26 on sheets 224-249 of the drawings are screenshots of Wall wash-related features of the examples [100a-d] of the lighting system.

Figures RMD1 to RMD14 on sheets 250-263 of the drawings are screenshots of features of examples [200] of another lighting system.

Figures ZAD29 to ZAD66 on sheets 264-301 of the drawings are screenshots of additional Z-Adjustment-related features of the examples [100a-d] of the lighting system.

DETAILED DESCRIPTION

Various lighting systems and processes that utilize semiconductor light-emitting devices have been designed. Many such lighting systems and processes exist that are capable of being mounted at a boundary. However, existing lighting systems and processes often have demonstrably failed to provide versatile control over the directions in which light is propagated away from a boundary, and have also demonstrably failed to provide easy access to the internal components of boundary-mounted lighting systems for servicing purposes such as, for example, adjustments in directional light emissions, and replacement of components such as light-emitting modules and power supply / driver units.

The following definitions of terms, being stated as applying “throughout this specification”, are hereby deemed to be incorporated throughout this specification, including but not limited to the Summary, Brief Description of the Figures, Detailed Description, and Claims.

Throughout this specification, the term “semiconductor” means: a substance, examples including a solid chemical element or compound, that can conduct electricity under some conditions but not others, making the substance a good medium for the control of electrical current.

Throughout this specification, the term “semiconductor light-emitting device” (also being abbreviated as “SLED”) means: a light-emitting diode; an organic light-emitting diode; a laser diode; or any other light-emitting device having one or more layers containing inorganic and/or organic semiconductor(s). Throughout this specification, the term “light-emitting diode” (herein also referred to as an “LED”) means: a two-lead semiconductor light source having an active pn-junction. As examples, an LED may include a series of semiconductor layers that may be epitaxially grown on a substrate such as, for example, a substrate that includes sapphire, silicon, silicon carbide, gallium nitride or gallium arsenide. Further, for example, one or more semiconductor p-n junctions may be formed in these epitaxial layers. When a sufficient voltage is applied across the p-n junction, for example, electrons in the n-type semiconductor layers and holes in the p-type semiconductor layers may flow toward the p-n junction. As the electrons and holes flow toward each other, some of the electrons may recombine with corresponding holes, and emit photons. The energy release is called electroluminescence, and the color of the light, which corresponds to the energy of the photons, is determined by the energy band gap of the semiconductor. As examples, a spectral power distribution of the light generated by an LED may generally depend on the particular semiconductor materials used and on the structure of the thin epitaxial layers that make up the “active region” of the device, being the area where the light is generated. As examples, an LED may have a light-emissive electroluminescent layer including an inorganic semiconductor, such as a Group III-V semiconductor, examples including: gallium nitride; silicon; silicon carbide; and zinc oxide. Throughout this specification, the term “organic light-emitting diode” (herein also referred to as an “OLED”) means: an LED having a light-emissive electroluminescent layer including an organic semiconductor, such as small organic molecules or an organic polymer. It is understood throughout this specification that a semiconductor light-emitting device may include: a non-semiconductor-substrate or a semiconductor-substrate; and may include one or more electrically-conductive contact layers. Further, it is understood throughout this specification that an LED may include a substrate formed of materials such as, for example: silicon carbide; sapphire; gallium nitride; or silicon. It is additionally understood throughout this specification that a semiconductor light-emitting device may have a cathode contact on one side and an anode contact on an opposite side, or may alternatively have both contacts on the same side of the device.

Further background information regarding semiconductor light-emitting devices is provided in the following documents, the entireties of all of which hereby are incorporated by reference herein: U.S. Pat. Nos. 7,564,180; 7,456,499; 7,213,940; 7,095,056; 6,958,497; 6,853,010; 6,791,119; 6,600,175; 6,201,262; 6,187,606; 6,120,600; 5,912,477; 5,739,554; 5,631,190; 5,604,135; 5,523,589; 5,416,342; 5,393,993; 5,359,345; 5,338,944; 5,210,051; 5,027,168; 5,027,168; 4,966,862; and 4,918,497; and U.S. Patent Application Publication Nos. 2014/0225511; 2014/0078715; 2013/0241392; 2009/0184616; 2009/0080185; 2009/0050908; 2009/0050907; 2008/0308825; 2008/0198112; 2008/0179611; 2008/0173884; 2008/0121921; 2008/0012036; 2007/0253209; 2007/0223219; 2007/0170447; 2007/0158668; 2007/0139923; and 2006/0221272.

Throughout this specification, the term “spectral power distribution” means: the emission spectrum of the one or more wavelengths of light emitted by a semiconductor light-emitting device. Throughout this specification, the term “peak wavelength” means: the wavelength where the spectral power distribution of a semiconductor light-emitting device reaches its maximum value as detected by a photo-detector. As an example, an LED may be a source of nearly monochromatic light and may appear to emit light having a single color. Thus, the spectral power distribution of the light emitted by such an LED may be centered about its peak wavelength. As examples, the “width” of the spectral power distribution of an LED may be within a range of between about 10 nanometers and about 30 nanometers, where the width is measured at half the maximum illumination on each side of the emission spectrum.

Throughout this specification, both of the terms “beam width” and “full-width-half-maximum” (“FWHM”) mean: the measured angle, being collectively defined by two mutually-opposed angular directions away from a center emission direction of a visible-light beam, at which an intensity of the visible-light emissions is half of a maximum intensity measured at the center emission direction. Throughout this specification, in the case of a visible-light beam having a non-circular shape, e.g. a visible-light beam having an elliptical shape, then the terms “beam width” and “full-width-half-maximum” (“FWHM”) mean: the measured maximum and minimum angles, being respectively defined in two mutually-orthogonal pairs of mutually-opposed angular directions away from a center emission direction of a visible-light beam, at which a respective intensity of the visible-light emissions is half of a corresponding maximum intensity measured at the center emission direction. Throughout this specification, the term “field angle” means: the measured angle, being collectively defined by two opposing angular directions away from a center emission direction of a visible-light beam, at which an intensity of the visible-light emissions is one-tenth of a maximum intensity measured at the center emission direction. Throughout this specification, in the case of a visible-light beam having a non-circular shape, e.g. a visible-light beam having an elliptical shape, then the term “field angle” means: the measured maximum and minimum angles, being respectively defined in two mutually-orthogonal pairs of mutually-opposed angular directions away from a center emission direction of a visible-light beam, at which a respective intensity of the visible-light emissions is one-tenth of a corresponding maximum intensity measured at the center emission direction.

Throughout this specification, the term “dominant wavelength” means: the wavelength of monochromatic light that has the same apparent color as the light emitted by a semiconductor light-emitting device, as perceived by the human eye. As an example, since the human eye perceives yellow and green light better than red and blue light, and because the light emitted by a semiconductor light-emitting device may extend across a range of wavelengths, the color perceived (i.e., the dominant wavelength) may differ from the peak wavelength.

Throughout this specification, the term “luminous flux”, also referred to as “luminous power”, means: the measure in lumens of the perceived power of light, being adjusted to reflect the varying sensitivity of the human eye to different wavelengths of light. Throughout this specification, the term “radiant flux” means: the measure of the total power of electromagnetic radiation without being so adjusted. Throughout this specification, the term “central axis” means a direction along which the light emissions of a semiconductor light-emitting device have a greatest radiant flux. It is understood throughout this specification that light emissions “along a central axis” means light emissions that: include light emissions in the direction of the central axis; and may further include light emissions in a plurality of other generally similar directions.

Throughout this specification, the term “color bin” means: the designated empirical spectral power distribution and related characteristics of a particular semiconductor light-emitting device. For example, individual light-emitting diodes (LEDs) are typically tested and assigned to a designated color bin (i.e., “binned”) based on a variety of characteristics derived from their spectral power distribution. As an example, a particular LED may be binned based on the value of its peak wavelength, being a common metric to characterize the color aspect of the spectral power distribution of LEDs. Examples of other metrics that may be utilized to bin LEDs include: dominant wavelength; and color point.

Throughout this specification, the term “luminescent” means: characterized by absorption of electromagnetic radiation (e.g., visible-light, UV light or infrared light) causing the emission of light by, as examples: fluorescence; and phosphorescence.

Throughout this specification, the term “object” means a material article or device. Throughout this specification, the term “surface” means an exterior boundary of an object. Throughout this specification, the term “incident visible-light” means visible-light that propagates in one or more directions towards a surface. Throughout this specification, the term “any incident angle” means any one or more directions from which visible-light may propagate towards a surface. Throughout this specification, the term “reflective surface” means a surface of an object that causes incident visible-light, upon reaching the surface, to then propagate in one or more different directions away from the surface without passing through the object. Throughout this specification, the term “planar reflective surface” means a generally flat reflective surface.

Throughout this specification, the term “reflection value” means a percentage of a radiant flux of incident visible-light having a specified wavelength that is caused by a reflective surface of an object to propagate in one or more different directions away from the surface without passing through the object. Throughout this specification, the term “reflected light” means the incident visible-light that is caused by a reflective surface to propagate in one or more different directions away from the surface without passing through the object. Throughout this specification, the term “Lambertian reflection” means diffuse reflection of visible-light from a surface, in which the reflected light has uniform radiant flux in all of the propagation directions. Throughout this specification, the term “specular reflection” means mirror-like reflection of visible-light from a surface, in which light from a single incident direction is reflected into a single propagation direction. Throughout this specification, the term “spectrum of reflection values” means a spectrum of values of percentages of radiant flux of incident visible-light, the values corresponding to a spectrum of wavelength values of visible-light, that are caused by a reflective surface to propagate in one or more different directions away from the surface without passing through the object. Throughout this specification, the term “transmission value” means a percentage of a radiant flux of incident visible-light having a specified wavelength that is permitted by a reflective surface to pass through the object having the reflective surface. Throughout this specification, the term “transmitted light” means the incident visible-light that is permitted by a reflective surface to pass through the object having the reflective surface.

Throughout this specification, the term “spectrum of transmission values” means a spectrum of values of percentages of radiant flux of incident visible-light, the values corresponding to a spectrum of wavelength values of visible-light, that are permitted by a reflective surface to pass through the object having the reflective surface. Throughout this specification, the term “absorption value” means a percentage of a radiant flux of incident visible-light having a specified wavelength that is permitted by a reflective surface to pass through the reflective surface and is absorbed by the object having the reflective surface. Throughout this specification, the term “spectrum of absorption values” means a spectrum of values of percentages of radiant flux of incident visible-light, the values corresponding to a spectrum of wavelength values of visible-light, that are permitted by a reflective surface to pass through the reflective surface and are absorbed by the object having the reflective surface. Throughout this specification, it is understood that a reflective surface, or an object, may have a spectrum of reflection values, and a spectrum of transmission values, and a spectrum of absorption values. The spectra of reflection values, absorption values, and transmission values of a reflective surface or of an object may be measured, for example, utilizing an ultraviolet-visible-near infrared (UV-VIS-NIR) spectrophotometer. Throughout this specification, the term “visible-light reflector” means an object having a reflective surface. In examples, a visible-light reflector may be selected as having a reflective surface characterized by light reflections that are more Lambertian than specular.

Throughout this specification, the term “lumiphor” means: a medium that includes one or more luminescent materials being positioned to absorb light that is emitted at a first spectral power distribution by a semiconductor light-emitting device, and to re-emit light at a second spectral power distribution in the visible or ultra violet spectrum being different than the first spectral power distribution, regardless of the delay between absorption and re-emission. Lumiphors may be categorized as being down-converting, i.e., a material that converts photons to a lower energy level (longer wavelength); or up-converting, i.e., a material that converts photons to a higher energy level (shorter wavelength). As examples, a luminescent material may include: a phosphor; a quantum dot;

a quantum wire; a quantum well; a photonic nanocrystal; a semiconducting nanoparticle; a scintillator; a lumiphoric ink; a lumiphoric organic dye; a day glow tape; a phosphorescent material; or a fluorescent material. Throughout this specification, the term “quantum material” means any luminescent material that includes: a quantum dot; a quantum wire; or a quantum well. Some quantum materials may absorb and emit light at spectral power distributions having narrow wavelength ranges, for example, wavelength ranges having spectral widths being within ranges of between about 25 nanometers and about 50 nanometers. In examples, two or more different quantum materials may be included in a lumiphor, such that each of the quantum materials may have a spectral power distribution for light emissions that may not overlap with a spectral power distribution for light absorption of any of the one or more other quantum materials. In these examples, cross-absorption of light emissions among the quantum materials of the lumiphor may be minimized. As examples, a lumiphor may include one or more layers or bodies that may contain one or more luminescent materials that each may be: (1) coated or sprayed directly onto an semiconductor light-emitting device; (2) coated or sprayed onto surfaces of a lens or other elements of packaging for an semiconductor light-emitting device; (3) dispersed in a matrix medium; or (4) included within a clear encapsulant (e.g., an epoxy-based or silicone-based curable resin or glass or ceramic) that may be positioned on or over an semiconductor light-emitting device. A lumiphor may include one or multiple types of luminescent materials. Other materials may also be included with a lumiphor such as, for example, fillers, diffusants, colorants, or other materials that may as examples improve the performance of or reduce the overall cost of the lumiphor. In examples where multiple types of luminescent materials may be included in a lumiphor, such materials may, as examples, be mixed together in a single layer or deposited sequentially in successive layers.

Throughout this specification, the term “volumetric lumiphor” means a lumiphor being distributed in an object having a shape including defined exterior surfaces. In some examples, a volumetric lumiphor may be formed by dispersing a lumiphor in a volume of a matrix medium having suitable spectra of visible-light transmission values and visible-light absorption values. As examples, such spectra may be affected by a thickness of the volume of the matrix medium, and by a concentration of the lumiphor being distributed in the volume of the matrix medium. In examples, the matrix medium may have a composition that includes polymers or oligomers of: a polycarbonate; a silicone; an acrylic; a glass; a polystyrene; or a polyester such as polyethylene terephthalate. Throughout this specification, the term “remotely-located lumiphor” means a lumiphor being spaced apart at a distance from and positioned to receive light that is emitted by a semiconductor light-emitting device.

Throughout this specification, the term “light-scattering particles” means small particles formed of a non-luminescent, non-wavelength-converting material. In some examples, a volumetric lumiphor may include light-scattering particles being dispersed in the volume of the matrix medium for causing some of the light emissions having the first spectral power distribution to be scattered within the volumetric lumiphor. As an example, causing some of the light emissions to be so scattered within the matrix medium may cause the luminescent materials in the volumetric lumiphor to absorb more of the light emissions having the first spectral power distribution. In examples, the light-scattering particles may include: rutile titanium dioxide; anatase titanium dioxide; barium sulfate; diamond; alumina; magnesium oxide; calcium titanate; barium titanate; strontium titanate; or barium strontium titanate. In examples, light-scattering particles may have particle sizes being within a range of about 0.01 micron (10 nanometers) and about 2.0 microns (2,000 nanometers).

In some examples, a visible-light reflector may be formed by dispersing light-scattering particles having a first index of refraction in a volume of a matrix medium having a second index of refraction being suitably different from the first index of refraction for causing the volume of the matrix medium with the dispersed light-scattering particles to have suitable spectra of reflection values, transmission values, and absorption values for functioning as a visible-light reflector. As examples, such spectra may be affected by a thickness of the volume of the matrix medium, and by a concentration of the light-scattering particles being distributed in the volume of the matrix medium, and by physical characteristics of the light-scattering particles such as the particle sizes and shapes, and smoothness or roughness of exterior surfaces of the particles. In an example, the smaller the difference between the first and second indices of refraction, the more light-scattering particles may need to be dispersed in the volume of the matrix medium to achieve a given amount of light-scattering. As examples, the matrix medium for forming a visible-light reflector may have a composition that includes polymers or oligomers of: a polycarbonate; a silicone; an acrylic; a glass; a polystyrene; or a polyester such as polyethylene terephthalate. In further examples, the light-scattering particles may include: rutile titanium dioxide; anatase titanium dioxide; barium sulfate; diamond; alumina; magnesium oxide; calcium titanate; barium titanate; strontium titanate; or barium strontium titanate. In other examples, a visible-light reflector may include a reflective polymeric or metallized surface formed on a visible-light — transmissive polymeric or metallic object such as, for example, a volume of a matrix medium. Additional examples of visible-light reflectors may include microcellular foamed polyethylene terephthalate sheets (“MCPET”). Suitable visible-light reflectors may be commercially available under the trade names White Optics® and MIRO® from WhiteOptics LLC, 243-G Quigley Blvd., New Castle, Del. 19720 USA. Suitable MCPET visible-light reflectors may be commercially available from the Furukawa Electric Co., Ltd., Foamed Products Division, Tokyo, Japan. Additional suitable visible-light reflectors may be commercially available from CVI Laser Optics, 200 Dorado Place SE, Albuquerque, N. Mex. 87123 USA.

In further examples, a volumetric lumiphor and a visible-light reflector may be integrally formed. As examples, a volumetric lumiphor and a visible-light reflector may be integrally formed in respective layers of a volume of a matrix medium, including a layer of the matrix medium having a dispersed lumiphor, and including another layer of the same or a different matrix medium having light-scattering particles being suitably dispersed for causing the another layer to have suitable spectra of reflection values, transmission values, and absorption values for functioning as the visible-light reflector. In other examples, an integrally-formed volumetric lumiphor and visible-light reflector may incorporate any of the further examples of variations discussed above as to separately-formed volumetric lumiphors and visible-light reflectors.

Throughout this specification, the term “phosphor” means: a material that exhibits luminescence when struck by photons. Examples of phosphors that may utilized include: CaAlSiN₃:Eu, SrAlSiN₃:Eu, CaAlSiN₃:Eu, Ba₃Si₆O₁₂N₂:Eu, Ba₂SiO₄:Eu, Sr₂SiO₄:Eu, Ca₂SiO₄:Eu, Ca₃Sc₂Si₃O₁₂:Ce, Ca₃Mg₂Si₃O₁₂:Ce, CaSc₂O₄:Ce, CaSi₂O₂N₂:Eu, SrSi₂O₂N₂:Eu, BaSi₂O₂N₂:Eu, Ca₅(PO₄)₃Cl:Eu, Ba₅(PO₄)₃Cl:Eu, Cs₂CaP₂O₇, Cs₂SrP₂O₇, SrGa₂S₄:Eu, Lu₃Al₅O₁₂:Ce, Ca₈Mg(SiO₄)₄Cl₂:Eu, Sr₈Mg(SiO₄)₄Cl₂:Eu, La₃Si₆N₁₁:Ce, Y₃Al₅O₁₂:Ce, Y₃Ga₅O₁₂:Ce, Gd₃Al₅O₁₂:Ce, Gd₃Ga₅O₁₂:Ce, Tb₃Al₅O₁₂:Ce, Tb₃Ga₅O₁₂:Ce, Lu₃Ga₅O₁₂:Ce, (SrCa)AlSiN₃:Eu, LuAG:Ce, (Y,Gd)₂Al₅)₁₂:Ce, CaS:Eu, SrS:Eu, SrGa₂S₄:E₄, Ca₂(Sc,Mg)₂SiO₁₂:Ce, Ca₂Sc₂Si₂)₁₂:C2, Ca₂Sc₂O₄:Ce, Ba₂Si₆O₁₂N₂:Eu, (Sr,Ca)AlSiN₂:Eu, and CaAlSiN₂:Eu.

Throughout this specification, the term “quantum dot” means: a nanocrystal made of semiconductor materials that are small enough to exhibit quantum mechanical properties, such that its excitons are confined in all three spatial dimensions.

Throughout this specification, the term “quantum wire” means: an electrically conducting wire in which quantum dfects influence the transport properties.

Throughout this specification, the term “quantum well” means: a thin layer that can confine (quasi-)particles (typically electrons or holes) in the dimension perpendicular to the layer surface, whereas the movement in the other dimensions is not restricted.

Throughout this specification, the term “photonic nanocrystal” means: a periodic optical nanostructure that affects the motion of photons, for one, two, or three dimensions, in much the same way that ionic: lattices affect electrons in solids.

Throughout this specification, the term “semiconducting nanoparticle” means: a particle having a dimension within a range of between about 1 nanometer and about 100 nanometers, being formed of a semiconductor.

Throughout this specification, the term “scintillator” means: a material that fluoresces when struck by photons.

Throughout this specification, the term “lumiphoric ink” means: a liquid composition containing a luminescent material. For example, a lumiphoric ink composition may contain semiconductor nanoparticles. Examples of lumiphoric ink compositions that may be utilized are disclosed in Cao et al., U.S. Patent Application Publication No. 20130221489 published on Aug. 29, 2013, the entirety of which hereby is incorporated herein by reference.

Throughout this specification, the term “lumiphoric organic dye” means an organic dye having luminescent up-converting or down-converting activity. As an example, some perylene-based dyes may be suitable.

Throughout this specification, the term “day glow tape” means: a tape material containing a luminescent material.

Throughout this specification, the term “CIE 1931 XY chromaticity diagram” means: the 1931 International Commission on Illumination two-dimensional chromaticity diagram, which defines the spectrum of perceived color points of visible-light by (x, y) pairs of chromaticity coordinates that fall within a generally U-shaped area that includes all of the hues perceived by the human eye. Each of the x and y axes of the CIE 1931 XY chromaticity diagram has a scale of between 0.0 and 0.8. The spectral colors are distributed around the perimeter boundary of the chromaticity diagram, the boundary encompassing all of the hues perceived by the human eye. The perimeter boundary itself represents maximum saturation for the spectral colors. The CIE 1931 XY chromaticity diagram is based on the three-dimensional CIE 1931 XYZ color space. The CIE 1931 XYZ color space utilizes three color matching functions to determine three corresponding tristimulus values which together express a given color point within the CIE 1931 XYZ three-dimensional color space. The CIE 1931 XY chromaticity diagram is a projection of the three-dimensional CIE 1931 XYZ color space onto a two-dimensional (x, y) space such that brightness is ignored. A technical description of the CIE 1931 XY chromaticity diagram is provided in, for example, the “Encyclopedia of Physical Science and Technology”, vol. 7, pp. 230-231 (Robert A Meyers ed., 1987); the entirety of which hereby is incorporated herein by reference. Further background information regarding the CIE 1931 XY chromaticity diagram is provided in Harbers et al., U.S. Patent Application Publication No. 2012/0224177A1 published on Sep. 6, 2012, the entirety of which hereby is incorporated herein by reference.

Throughout this specification, the term “color point” means: an (x, y) pair of chromaticity coordinates falling within the CIE 1931 XY chromaticity diagram. Color points located at or near the perimeter boundary of the CIE 1931 XY chromaticity diagram are saturated colors composed of light having a single wavelength, or having a very small spectral power distribution. Color points away from the perimeter boundary within the interior of the CIE 1931 XY chromaticity diagram are unsaturated colors that are composed of a mixture of different wavelengths.

Throughout this specification, the term “combined light emissions” means: a plurality of different light emissions that are mixed together. Throughout this specification, the term “combined color point” means: the color point, as perceived by human eyesight, of combined light emissions. Throughout this specification, a “substantially constant” combined color points are: color points of combined light emissions that are perceived by human eyesight as being uniform, i.e., as being of the same color.

Throughout this specification, the term “Planckian — black-body locus” means the curve within the CIE 1931 XY chromaticity diagram that plots the chromaticity coordinates (i.e., color points) that obey Planck's equation: E(λ)=Aλ−5/(eB/T−1), where E is the emission intensity, X is the emission wavelength, T is the color temperature in degrees Kelvin of a black-body radiator, and A and B are constants. The Planckian-black-body locus corresponds to the locations of color points of light emitted by a black-body radiator that is heated to various temperatures. As a black-body radiator is gradually heated, it becomes an incandescent light emitter (being referred to throughout this specification as an “incandescent light emitter”) and first emits reddish light, then yellowish light, and finally bluish light with increasing temperatures. This incandescent glowing occurs because the wavelength associated with the peak radiation of the black-body radiator becomes progressively shorter with gradually increasing temperatures, consistent with the Wien Displacement Law. The CIE 1931 XY chromaticity diagram further includes a series of lines each having a designated corresponding temperature listing in units of degrees Kelvin spaced apart along the Planckian-black-body locus and corresponding to the color points of the incandescent light emitted by a black-body radiator having the designated temperatures. Throughout this specification, such a temperature listing is referred to as a “correlated color temperature” (herein also referred to as the “CCT”) of the corresponding color point. Correlated color temperatures are expressed herein in units of degrees Kelvin (K). Throughout this specification, each of the lines having a designated temperature listing is referred to as an “isotherm” of the corresponding correlated color temperature.

Throughout this specification, the term “chromaticity bin” means: a bounded region within the CIE 1931 XY chromaticity diagram. As an example, a chromaticity bin may be defined by a series of chromaticity (x,y) coordinates, being connected in series by lines that together form the bounded region. As another example, a chromaticity bin may be defined by several lines or other boundaries that together form the bounded region, such as: one or more isotherms of CCT's; and one or more portions of the perimeter boundary of the CIE 1931 chromaticity diagram.

Throughout this specification, the term “delta(uv)” means: the shortest distance of a given color point away from (i.e., above or below) the Planckian-black-body locus. In general, color points located at a delta(uv) of about equal to or less than 0.015 may be assigned a correlated color temperature (CCT).

Throughout this specification, the term “greenish-blue light” means: light having a perceived color point being within a range of between about 490 nanometers and about 482 nanometers (herein referred to as a “greenish-blue color point.”).

Throughout this specification, the term “blue light” means: light having a perceived color point being within a range of between about 482 nanometers and about 470 nanometers (herein referred to as a “blue color point.”).

Throughout this specification, the term “purplish-blue light” means: light having a perceived color point being within a range of between about 470 nanometers and about 380 nanometers (herein referred to as a “purplish-blue color point.”).

Throughout this specification, the term “reddish-orange light” means: light having a perceived color point being within a range of between about 610 nanometers and about 620 nanometers (herein referred to as a “reddish-orange color point.”).

Throughout this specification, the term “red light” means: light having a perceived color point being within a range of between about 620 nanometers and about 640 nanometers (herein referred to as a “red color point.”).

Throughout this specification, the term “deep red light” means: light having a perceived color point being within a range of between about 640 nanometers and about 670 nanometers (herein referred to as a “deep red color point.”).

Throughout this specification, the term “visible-light” means light having one or more wavelengths being within a range of between about 380 nanometers and about 670 nanometers; and “visible-light spectrum” means the range of wavelengths of between about 380 nanometers and about 670 nanometers.

Throughout this specification, the term “white light” means: light having a color point located at a delta(uv) of about equal to or less than 0.006 and having a CCT being within a range of between about 10000K and about 1800K (herein referred to as a “white color point.”). Many different hues of light may be perceived as being “white.” For example, some “white” light, such as light generated by a tungsten filament incandescent lighting device, may appear yellowish in color, while other “white” light, such as light generated by some fluorescent lighting devices, may appear more bluish in color. As examples, white light having a CCT of about 3000K may appear yellowish in color, while white light having a CCT of about equal to or greater than 8000K may appear more bluish in color and may be referred to as “cool” white light. Further, white light having a CCT of between about 2500K and about 4500K may appear reddish or yellowish in color and may be referred to as “warm” white light. “White light” includes light having a spectral power distribution of wavelengths including red, green and blue color points. In an example, a CCT of a lumiphor may be tuned by selecting one or more particular luminescent materials to be included in the lumiphor. For example, light emissions from a semiconductor light-emitting device that includes three separate emitters respectively having red, green and blue color points with an appropriate spectral power distribution may have a white color point. As another example, light perceived as being “white” may be produced by mixing light emissions from a semiconductor light-emitting device having a blue, greenish-blue or purplish-blue color point together with light emissions having a yellow color point being produced by passing some of the light emissions having the blue, greenish-blue or purplish-blue color point through a lumiphor to down-convert them into light emissions having the yellow color point. General background information on systems and processes for generating light perceived as being “white” is provided in “Class A Color Designation for Light Sources Used in General Illumination”, Freyssinier and Rea, J. Light & Vis. Env., Vol. 37, No. 2 & 3 (Nov. 7, 2013, Illuminating Engineering Institute of Japan), pp. 10-14; the entirety of which hereby is incorporated herein by reference.

Throughout this specification, the term “color rendition index” (herein also referred to as “CRI-Ra”) means: the quantitative measure on a scale of 1-100 of the capability of a given light source to accurately reveal the colors of one or more objects having designated reference colors, in comparison with the capability of a black-body radiator to accurately reveal such colors. The CRI-Ra of a given light source is a modified average of the relative measurements of color renditions by that light source, as compared with color renditions by a reference black-body radiator, when illuminating objects having the designated reference color(s). The CRI is a relative measure of the shift in perceived surface color of an object when illuminated by a particular light source versus a reference black-body radiator. The CRI-Ra will equal 100 if the color coordinates of a set of test colors being illuminated by the given light source are the same as the color coordinates of the same set of test colors being irradiated by the black-body radiator. The CRI system is administered by the International Commission on Illumination (CIE). The CIE selected fifteen test color samples (respectively designated as Ri_1-15) to grade the color properties of a white light source. The first eight test color samples (respectively designated as Ri_1-8) are relatively low saturated colors and are evenly distributed over the complete range of hues. These eight samples are employed to calculate the general color rendering index Ra. The general color rendering index Ra is simply calculated as the average of the first eight color rendering index values, R_1-8. An additional seven samples (respectively designated as R_9-15) provide supplementary information about the color rendering properties of a light source; the first four of them focus on high saturation, and the last three of them are representative of well-known objects. A set of color rendering index values, R_1-15, can be calculated for a particular correlated color temperature (CCT) by comparing the spectral response of a light source against that of each test color sample, respectively. As another example, the CRI-Ra may consist of one test color, such as the designated red color of R₉.

As examples, sunlight generally has a CRI-Ra of about 100; incandescent light bulbs generally have a CRI-Ra of about 95; fluorescent lights generally have a CRI-Ra of about 70 to 85; and monochromatic light sources generally have a CRI-Ra of about zero. As an example, a light source for general illumination applications where accurate rendition of object colors may not be considered important may generally need to have a CRI-Ra value being within a range of between about 70 and about 80. Further, for example, a light source for general interior illumination applications may generally need to have a CRI-Ra value being at least about 80. As an additional example, a light source for general illumination applications where objects illuminated by the lighting device may be considered to need to appear to have natural coloring to the human eye may generally need to have a CRI-Ra value being at least about 85. Further, for example, a light source for general illumination applications where good rendition of perceived object colors may be considered important may generally need to have a CRI-Ra value being at least about 90.

Throughout this specification, the term “in contact with” means: that a first object, being “in contact with” a second object, is in either direct or indirect contact with the second object. Throughout this specification, the term “in indirect contact with” means: that the first object is not in direct contact with the second object, but instead that there are a plurality of objects (including the first and second objects), and each of the plurality of objects is in direct contact with at least one other of the plurality of objects (e.g., the first and second objects are in a stack and are separated by one or more intervening layers). Throughout this specification, the term “in direct contact with” means: that the first object, which is “in direct contact” with a second object, is touching the second object and there are no intervening objects between at least portions of both the first and second objects.

Throughout this specification, the term “spectrophotometer” means: an apparatus that can measure a light beam's intensity as a function of its wavelength and calculate its total luminous flux.

Throughout this specification, the term “integrating sphere-spectrophotometer” means: a spectrophotometer operationally connected with an integrating sphere. An integrating sphere (also known as an Ulbricht sphere) is an optical component having a hollow spherical cavity with its interior covered with a diffuse white reflective coating, with small holes for entrance and exit ports. Its relevant property is a uniform scattering or diffusing effect. Light rays incident on any point on the inner surface are, by multiple scattering reflections, distributed equally to all other points. The effects of the original direction of light are minimized. An integrating sphere may be thought of as a diffuser which preserves power but destroys spatial information. Another type of integrating sphere that can be utilized is referred to as a focusing or Coblentz sphere. A Coblentz sphere has a mirror-like (specular) inner surface rather than a diffuse inner surface. Light scattered by the interior of an integrating sphere is evenly distributed over all angles. The total power (radiant flux) of a light source can then be measured without inaccuracy caused by the directional characteristics of the source. Background information on integrating sphere-spectrophotometer apparatus is provided in Liu et al., U.S. Pat. No. 7,532,324 issued on May 12, 2009, the entirety of which hereby is incorporated herein by reference. It is understood throughout this specification that color points may be measured, for example, by utilizing a spectrophotometer, such as an integrating sphere-spectrophotometer. The spectra of reflection values, absorption values, and transmission values of a reflective surface or of an object may be measured, for example, utilizing an ultraviolet-visible-near infrared (UV-VIS-NIR) spectrophotometer.

Throughout this specification, the term “diffuse refraction” means refraction from an object's surface that scatters the visible-light emissions, casting multiple jittered light rays forming combined light emissions having a combined color point.

Throughout this specification, each of the words “include”, “contain”, and “have” is interpreted broadly as being open to the addition of further like elements as well as to the addition of unlike elements.