Systems and methods for providing tunable warm white light
12123582 ยท 2024-10-22
Assignee
Inventors
Cpc classification
F21Y2103/10
MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
H05B45/24
ELECTRICITY
H01L33/504
ELECTRICITY
F21V23/0442
MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
F21Y2115/10
MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
H01L25/13
ELECTRICITY
F21K9/64
MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
International classification
F21V23/04
MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
F21K9/64
MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
H01L25/13
ELECTRICITY
Abstract
The present disclosure provides methods for generating tunable white light. The methods include using a plurality of LED strings to generate light with color points that fall within white, red, and cyan color ranges, with each LED string being driven with a separately controllable drive current in order to tune the generated light output.
Claims
1. A system of generating tunable white light, comprising: a first channel for emitting white light, said white light being light has a first color point within a 7-step MacAdam ellipse around any point on the black body locus having a correlated color temperature between about 3500K and about 6500K; and at least one of a second or third channel, said second channel emitting red light, said third channel emitting cyan light, wherein said red light is defined by the spectral locus between the constant CCT line of 1600K and the line of purples, the line of purples, a line connecting the ccx, ccy color coordinates (0.61, 0.21) and (0.47, 0.28), and the constant CCT line of 1600K, and wherein said cyan light is defined by a line connecting the ccx, ccy color coordinates (0.18, 0.55) and (0.27, 0.72), the constant CCT line of 9000K, the Planckian locus between 9000K and 1800K, the constant CCT line of 1800K, and the spectral locus; wherein said cyan light has a spectral power distribution that falls between 3.9% to 130.6% for wavelengths between 380 nm to 420 nm, 100% for wavelengths between 421 nm to 460 nm, between 112.7% to 553.9% for wavelengths between 461 nm to 500 nm, between 306.2% to 5472.8% for wavelengths between 501 nm to 540 nm, between 395.1% to 9637.9% for wavelengths between 541 nm to 580 nm, between 318.2% to 12476.9% for wavelengths between 581 nm to 620 nm, between 245% to 13285.5% for wavelengths between 621 nm to 660 nm, between 138.8% to 6324.7% for wavelengths between 661 nm to 700 nm, between 39.5% to 1620.3% for wavelengths between 701 nm to 740 nm, and between 10.3% to 344.7% for wavelengths between 741 nm to 780 nm; and circuitry for independently driving said first, and at least one of said second or third channels to emit said tunable white light, said tunable white light corresponding to at least one of a plurality of points along a predefined path near the black body locus in the 1931 CIE Chromaticity Diagram within a 7-step MacAdam ellipse around any point on the black body locus having a correlated color temperature between about 1800K and about 3200K.
2. The system of claim 1, wherein said system comprising said second and third channels, and said circuitry is configured to drive both of said second and third channels.
3. The system of claim 1, wherein said white light is defined by a polygonal region on the 1931 CIE Chromaticity Diagram defined by the following ccx, ccy color coordinates: (0.4006, 0.4044), (0.3736, 0.3874), (0.3670, 0.3578), (0.3898, 0.3716).
4. The system of claim 1, wherein said white light is within a single 5-step MacAdam ellipse with center point (0.3818, 0.3797) with a major axisa of 0.01565, minor axisb of 0.00670, with an ellipse rotation angle Q of 52.70 relative to a line of constant ccy values.
5. The system of claim 1, wherein said red light is defined by a 20-step MacAdam ellipse at 1200K, 20 points below the Planckian locus.
6. The system of claim 1, wherein said red light is defined by region bounded by lines connecting (0.576, 0.393), (0.583, 0.400), (0.604, 0.387), and (0.597, 0.380).
7. The system of claim 1, wherein said red light has a spectral power distribution that falls between 0.0% to 14.8% for wavelengths between 380 nm to 420 nm, between 2.1% to 15% for wavelengths between 421 nm to 460 nm, between 2.0% to 6.7% for wavelengths between 461 nm to 500 nm, between 1.4% to 12.2% for wavelengths between 501 nm to 540 nm, between 8.7% to 24.7% for wavelengths between 541 nm to 580 nm, between 48.5% and 102.8% for wavelengths between 581 nm to 620 nm, 100% for wavelengths between 621 nm to 660 nm, between 1.8% to 74.3% for wavelengths between 661 nm to 700 nm, between 0.5% to 29.5% for wavelengths between 701 nm to 740 nm, and between 0.3% to 9.0% for wavelengths between 741 nm to 780 nm.
8. The system of claim 1, wherein said red light has a spectral power distribution that falls between 0% to 0.1% for wavelengths between 380 nm to 420 nm, between 2.3% to 2.7% for wavelengths between 421 nm to 460 nm, between 4.3% to 5% for wavelengths between 461 nm to 500 nm, between 9.5% to 10.2% for wavelengths between 501 nm to 540 nm, between 24.6% to 24.7% for wavelengths between 541 nm to 580 nm, between 60.4% to 61% for wavelengths between 581 nm to 620 nm, 100% for wavelengths between 621 nm to 660 nm, between 51.5% to 71.7% for wavelengths between 661 nm to 700 nm, between 12.4% to 27.8% for wavelengths between 701 nm to 740 nm, and between 2.4% to 8.4% for wavelengths between 741 nm to 780 nm.
9. The system of claim 1, wherein said cyan light is defined by region bounded by (0.360, 0.495), (0.371, 0.518), (0.388, 0.522), and (0.377, 0.499).
10. The system of claim 1, wherein said cyan light has a spectral power distribution that falls between 3.9% to 30.6% for wavelengths between 380 nm to 420 nm, 100% for wavelengths between 421 nm to 460 nm, between 112.7% to 553.9% for wavelengths between 461 nm to 500 nm, between 306.2% to 2660.6% for wavelengths between 501 nm to 540 nm, between 395.1% to 4361.9% for wavelengths between 541 nm to 580 nm, between 318.2% to 3708.8% for wavelengths between 581 nm to 620 nm, between 245% to 2223.8% for wavelengths between 621 nm to 660 nm, between 138.8% to 712.2% for wavelengths between 661 nm to 700 nm, between 39.5% to 285.6% for wavelengths between 701 nm to 740 nm, and between 10.3% to 99.6% for wavelengths between 741 nm to 780 nm.
11. The system of claim 1, wherein said tunable white light has an Rf greater than or equal to about 85, Rg greater than or equal to about 90.
12. The system of claim 1, wherein said tunable white light has an Rf greater than or equal to about 88, Rg greater than or equal to about 95.
13. The system of claim 1, wherein said tunable white light has Ra greater than or equal to about 90, and R9 greater than or equal to about 60.
Description
DRAWINGS
(1) The summary, as well as the following detailed description, is further understood when read in conjunction with the appended drawings. For the purpose of illustrating the disclosure, there are shown in the drawings exemplary implementations of the disclosure; however, the disclosure is not limited to the specific methods, compositions, and devices disclosed. In addition, the drawings are not necessarily drawn to scale. In the drawings:
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(11) All descriptions and callouts in the Figures are hereby incorporated by this reference as if fully set forth herein.
FURTHER DISCLOSURE
(12) The present disclosure may be understood more readily by reference to the following detailed description taken in connection with the accompanying figures and examples, which form a part of this disclosure. It is to be understood that this disclosure is not limited to the specific devices, methods, applications, conditions or parameters described and/or shown herein, and that the terminology used herein is for the purpose of describing particular exemplars by way of example only and is not intended to be limiting of the claimed disclosure. Also, as used in the specification including the appended claims, the singular forms a, an, and the include the plural, and reference to a particular numerical value includes at least that particular value, unless the context clearly dictates otherwise. The term plurality, as used herein, means more than one. When a range of values is expressed, another exemplar includes from the one particular value and/or to the other particular value. Similarly, when values are expressed as approximations, by use of the antecedent about, it will be understood that the particular value forms another exemplar. All ranges are inclusive and combinable.
(13) It is to be appreciated that certain features of the disclosure which are, for clarity, described herein in the context of separate exemplar, may also be provided in combination in a single exemplary implementation. Conversely, various features of the disclosure that are, for brevity, described in the context of a single exemplary implementation, may also be provided separately or in any subcombination. Further, reference to values stated in ranges include each and every value within that range.
(14) In one aspect, the present disclosure provides semiconductor light emitting devices 100 that can have a plurality of light emitting diode (LED) strings. Each LED string can have one, or more than one, LED. As depicted schematically in
(15) A recipient luminophoric medium 102A, 102B, or 102C includes one or more luminescent materials and is positioned to receive light that is emitted by an LED or other semiconductor light emitting device. In some implementations, recipient luminophoric mediums include layers having luminescent materials that are coated or sprayed directly onto a semiconductor light emitting device or on surfaces of the packaging thereof, and clear encapsulants that include luminescent materials that are arranged to partially or fully cover a semiconductor light emitting device. A recipient luminophoric medium may include one medium layer or the like in which one or more luminescent materials are mixed, multiple stacked layers or mediums, each of which may include one or more of the same or different luminescent materials, and/or multiple spaced apart layers or mediums, each of which may include the same or different luminescent materials. Suitable encapsulants are known by those skilled in the art and have suitable optical, mechanical, chemical, and thermal characteristics. In some implementations, encapsulants can include dimethyl silicone, phenyl silicone, epoxies, acrylics, and polycarbonates. In some implementations, a recipient luminophoric medium can be spatially separated (i.e., remotely located) from an LED or surfaces of the packaging thereof. In some implementations, such spatial segregation may involve separation of a distance of at least about 1 mm, at least about 2 mm, at least about 5 mm, or at least about 10 mm. In certain embodiments, conductive thermal communication between a spatially segregated luminophoric medium and one or more electrically activated emitters is not substantial. Luminescent materials can include phosphors, scintillators, day glow tapes, nanophosphors, inks that glow in visible spectrum upon illumination with light, semiconductor quantum dots, or combinations thereof.
(16) In certain implementations, the recipient luminophoric mediums can be provided as volumetric light converting elements having luminescent materials dispersed throughout a volume of matrix material. Each volumetric light converting element can be provided within at least a portion of a reflective cavity disposed above a semiconductor light emitting device. In some implementations, each volumetric light converting element can be provided as spatially separated from the top surface of the associated semiconductor light emitting device, with a void or air gap between the volumetric light converting element and the associated semiconductor light emitting device. In other implementations, each volumetric light converting element can be provided within substantially all of a reflective cavity such that the bottom surface of each volumetric light converting element is adjacent to the top surface of the associated LED. In some implementations, an index matching compound can be provided between the adjacent surfaces to avoid any voids or air gaps between the surfaces so that the light emitted by the LED may pass from the LED to the volumetric light converting element with minimized reflection and refraction. Suitable implementations of volumetric light converting elements are more fully described in International Patent Applications PCT/US2017/047217 entitled Illuminating with a Multizone Mixing Cup, and PCT/US2017/047224 entitled Illuminating with a Multizone Mixing Cup, the entirety of which are hereby incorporated by this reference as if fully set forth herein.
(17) In some implementations, the luminescent materials may comprise phosphors comprising one or more of the following materials: BaMg.sub.2Al.sub.16O.sub.27:Eu.sup.2+, BaMg.sub.2Al.sub.16O.sub.27:Eu.sup.2+,Mn.sup.2+, CaSiO.sub.3:Pb,Mn, CaWO.sub.4:Pb, MgWO.sub.4, Sr.sub.5Cl(PO.sub.4).sub.3:Eu.sup.2+, Sr.sub.2P.sub.2O.sub.7:Sn.sup.2+, Sr.sub.6P.sub.5BO.sub.20:Eu, Ca.sub.5F(PO.sub.4).sub.3:Sb, (Ba,Ti).sub.2P.sub.2O.sub.7:Ti, Sr.sub.5F(PO.sub.4).sub.3:Sb,Mn, (La,Ce,Tb)PO.sub.4:Ce,Tb, (Ca,Zn,Mg).sub.3(PO.sub.4).sub.2:Sn, (Sr,Mg).sub.3(PO.sub.4).sub.2:Sn, Y.sub.2O.sub.3:Eu.sup.3+, Mg.sub.4(F)GeO.sub.6:Mn, LaMgAl.sub.11O.sub.19:Ce, LaPO.sub.4:Ce, SrAl.sub.12O.sub.19:Ce, BaSi.sub.2O.sub.5:Pb, SrB.sub.4O.sub.7:Eu, Sr.sub.2MgSi.sub.2O.sub.7:Pb, Gd.sub.2O.sub.2S:Tb, Gd.sub.2O.sub.2S:Eu, Gd.sub.2O.sub.2S:Pr, Gd.sub.2O.sub.2S:Pr,Ce,F, Y.sub.2O.sub.2S:Tb, Y.sub.2O.sub.2S:Eu, Y.sub.2O.sub.2S:Pr, Zn(0.5)Cd(0.4)S:Ag, Zn(0.4)Cd(0.6)S:Ag, Y.sub.2SiO.sub.5:Ce, YAlO.sub.3:Ce, Y.sub.3(Al,Ga).sub.5O.sub.12:Ce, CdS:In, ZnO:Ga, ZnO:Zn, (Zn,Cd)S:Cu,Al, ZnCdS:Ag,Cu, ZnS:Ag, ZnS:Cu, NaI:Tl, CsI:Tl, .sup.6LiF/ZnS:Ag, .sup.6LiF/ZnS:Cu,Al,Au, ZnS:Cu,Al, ZnS:Cu,Au,Al, CaAlSiN.sub.3:Eu, (Sr,Ca)AlSiN.sub.3:Eu, (Ba,Ca,Sr,Mg).sub.2SiO.sub.4:Eu, Lu.sub.3Al.sub.5O.sub.12:Ce, Eu.sup.3+(Gd.sub.0.9Y.sub.0.1).sub.3Al.sub.5O.sub.12:Bi.sup.3+,Tb.sup.3+, Y.sub.3Al.sub.5O.sub.12:Ce, (La,Y).sub.3Si.sub.6N.sub.11:Ce, Ca.sub.2Al Si.sub.3O.sub.2N.sub.5:Ce.sup.3+, Ca.sub.2AlSi.sub.3O.sub.2N.sub.5:Eu.sup.2+, BaMgAl.sub.10O.sub.17:Eu, Sr.sub.5(PO.sub.4).sub.3Cl: Eu, (Ba,Ca,Sr,Mg).sub.2SiO.sub.4:Eu, Si.sub.6zAl.sub.zN.sub.8zO.sub.z:Eu (wherein 0<z4.2); M.sub.3Si.sub.6O.sub.12N.sub.2:Eu (wherein M=alkaline earth metal element), (Mg,Ca,Sr,Ba)Si.sub.2O.sub.2N.sub.2:Eu, Sr.sub.4Al.sub.14O.sub.25:Eu, (Ba,Sr,Ca)Al.sub.2O.sub.4:Eu, (Sr,Ba)Al.sub.2Si.sub.2O.sub.8:Eu, (Ba,Mg).sub.2SiO.sub.4:Eu, (Ba,Sr,Ca).sub.2(Mg, Zn)Si.sub.2O.sub.7:Eu, (Ba,Ca,Sr,Mg).sub.9(Sc,Y,Lu,Gd).sub.2(Si,Ge).sub.6O.sub.24:Eu, Y.sub.2SiO.sub.5:CeTb, Sr.sub.2P.sub.2O.sub.7Sr.sub.2B.sub.2O.sub.5:Eu, Sr.sub.2Si.sub.3O.sub.8-2SrCl.sub.2:Eu, Zn.sub.2SiO.sub.4:Mn, CeMgAl.sub.11O.sub.19:Tb, Y.sub.3Al.sub.5O.sub.12:Tb, Ca.sub.2Y.sub.8(SiO.sub.4).sub.6O.sub.2:Tb, La.sub.3Ga.sub.5SiO.sub.14:Tb, (Sr,Ba,Ca)Ga.sub.2S.sub.4:Eu,Tb,Sm, Y.sub.3(Al,Ga).sub.5O.sub.12:Ce, (Y,Ga,Tb,La,Sm,Pr,Lu).sub.3(Al,Ga).sub.5O.sub.12:Ce, Ca.sub.3Sc.sub.2Si.sub.3O.sub.12:Ce, Ca.sub.3(Sc,Mg,Na,Li).sub.2Si.sub.3O.sub.12:Ce, CaSc.sub.2O.sub.4:Ce, Eu-activated -Sialon, SrAl.sub.2O.sub.4:Eu, (La,Gd,Y).sub.2O.sub.2S:Tb, CeLaPO.sub.4:Tb, ZnS:Cu,Al, ZnS:Cu,Au,Al, (Y,Ga,Lu,Sc,La)BO.sub.3:Ce,Tb, Na.sub.2Gd.sub.2B.sub.2O.sub.7:Ce,Tb, (Ba,Sr).sub.2(Ca,Mg,Zn)B.sub.2O.sub.6:K,Ce,Tb, Ca.sub.8Mg(SiO.sub.4).sub.4Cl.sub.2:Eu,Mn, (Sr,Ca,Ba)(Al,Ga,In).sub.2S.sub.4:Eu, (Ca,Sr).sub.8 (Mg,Zn)(SiO.sub.4).sub.4Cl.sub.2:Eu,Mn, M.sub.3Si.sub.6O.sub.9N.sub.4:Eu, Sr.sub.5Al.sub.5Si.sub.21O.sub.2N.sub.35:Eu, Sr.sub.3Si.sub.13Al.sub.3N.sub.21O.sub.2:Eu, (Mg,Ca,Sr,Ba).sub.2Si.sub.5N.sub.8:Eu, (La,Y).sub.2O.sub.2S:Eu, (Y,La,Gd,Lu).sub.2O.sub.2S:Eu, Y(V,P)O.sub.4:Eu, (Ba,Mg).sub.2SiO.sub.4:Eu,Mn, (Ba,Sr, Ca,Mg).sub.2SiO.sub.4:Eu,Mn, LiW.sub.2O.sub.8:Eu, LiW.sub.2O.sub.8:Eu,Sm, Eu.sub.2W.sub.2O.sub.9, Eu.sub.2W.sub.2O.sub.9:Nb and Eu.sub.2W.sub.2O.sub.9:Sm, (Ca,Sr)S:Eu, YAlO.sub.3:Eu, Ca.sub.2Y.sub.8(SiO.sub.4).sub.6O.sub.2:Eu, LiY.sub.9(SiO.sub.4).sub.6O.sub.2:Eu, (Y,Gd).sub.3Al.sub.5O.sub.12:Ce, (Tb,Gd).sub.3Al.sub.5O.sub.12:Ce, (Mg,Ca,Sr,Ba).sub.2Si.sub.5(N,O).sub.8:Eu, (Mg,Ca,Sr,Ba)Si(N,O).sub.2:Eu, (Mg,Ca,Sr,Ba)AlSi(N,O).sub.3:Eu, (Sr,Ca,Ba,Mg).sub.10(PO.sub.4).sub.6Cl.sub.2:Eu, Mn, Eu,Ba.sub.3MgSi.sub.2O.sub.8:Eu,Mn, (Ba,Sr,Ca,Mg).sub.3(Zn,Mg)Si.sub.2O.sub.8:Eu,Mn, (kx)MgO.Math.xAF.sub.2.GeO.sub.2:yMn.sup.4+ (wherein k=2.8 to 5, x=0.1 to 0.7, y=0.005 to 0.015, A=Ca, Sr, Ba, Zn or a mixture thereof), Eu-activated -Sialon, (Gd,Y,Lu,La).sub.2O.sub.3:Eu, Bi, (Gd,Y,Lu,La).sub.2O.sub.2S:Eu,Bi, (Gd,Y, Lu,La)VO.sub.4:Eu,Bi, SrY.sub.2S.sub.4:Eu,Ce, CaLa.sub.2S.sub.4:Ce,Eu, (Ba,Sr,Ca)MgP.sub.2O.sub.7:Eu, Mn, (Sr,Ca,Ba,Mg,Zn).sub.2P.sub.2O.sub.7:Eu,Mn, (Y,Lu).sub.2WO.sub.6:Eu,Ma, (Ba,Sr,Ca).sub.xSi.sub.yN.sub.z:Eu,Ce (wherein x, y and z are integers equal to or greater than 1),(Ca,Sr,Ba,Mg).sub.10(PO.sub.4).sub.6(F,Cl,Br,OH):Eu,Mn, ((Y,Lu,Gd,Tb).sub.1-x-ySc.sub.xCe.sub.y).sub.2(Ca,Mg)(Mg,Zn).sub.2+rSi.sub.zqGe.sub.qO.sub.12+, SrAlSi.sub.4N.sub.7, Sr.sub.2Al.sub.2Si.sub.9O.sub.2N.sub.14:Eu, (wherein M.sup.1.sub.aM.sup.2.sub.bM.sup.3.sub.cO.sub.d (wherein M.sup.1=activator element including at least Ce, M.sup.2=bivalent metal element, M.sup.3=trivalent metal element, 0.0001a0.2, 0.8b1.2, 1.6c2.4 and 3.2d4.8), A.sub.2+xM.sub.yMn.sub.zF.sub.n (wherein A=Na and/or K; M=Si and Al, and 1x1, 0.9y+z1.1, 0.001z0.4 and 5n7), KSF/KSNAF, or (La.sub.1-x-y, Eu.sub.x, Ln.sub.y).sub.2O.sub.25 (wherein 0.02x0.50 and 0y0.50, Ln=Y.sup.3+, Gd.sup.3+, Lu.sup.3+, Sc.sup.3+, Sm.sup.3+ or Er.sup.3+). In some preferred implementations, the luminescent materials may comprise phosphors comprising one or more of the following materials: CaAlSiN.sub.3:Eu, (Sr,Ca)AlSiN.sub.3:Eu, BaMgAl.sub.10O.sub.17:Eu, (Ba,Ca,Sr,Mg).sub.2SiO.sub.4:Eu, -SiAlON, Lu.sub.3Al.sub.5O.sub.12:Ce, EU.sup.3+(Cd.sub.0.9Y.sub.0.1).sub.3Al.sub.5O.sub.12:Bi.sup.3+,Tb.sup.3+, Y.sub.3Al.sub.5O.sub.12:Ce, La.sub.3Si.sub.6N.sub.11:Ce, (La,Y).sub.3Si.sub.6N.sub.11:Ce, Ca.sub.2AlSi.sub.3O.sub.2N.sub.5:Ce.sup.3+, Ca.sub.2AlSi.sub.3O.sub.2N.sub.5:Ce.sup.3+,Eu.sup.2+, Ca.sub.2AlSi.sub.3O.sub.2N.sub.5:Eu.sup.2+, BaMgAl.sub.10O.sub.17:Eu.sup.2+, Sr.sub.4.5Eu.sub.0.5(PO.sub.4).sub.3Cl, or M.sup.1.sub.aM.sup.2.sub.bM.sup.3.sub.cO.sub.d (wherein M.sup.1=activator element comprising Ce, M.sup.2=bivalent metal element, M.sup.3=trivalent metal element, 0.0001a0.2, 0.8b1.2, 1.6c2.4 and 3.2d4.8). In further preferred implementations, the luminescent materials may comprise phosphors comprising one or more of the following materials: CaAlSiN.sub.3:Eu, BaMgAl.sub.10O.sub.17:Eu, Lu.sub.3Al.sub.5O.sub.12:Ce, or Y.sub.3Al.sub.5O.sub.12:Ce.
(18) Some implementations of the present invention relate to use of solid state emitter packages. A solid state emitter package typically includes at least one solid state emitter chip that is enclosed with packaging elements to provide environmental and/or mechanical protection, color selection, and light focusing, as well as electrical leads, contacts or traces enabling electrical connection to an external circuit. Encapsulant material, optionally including luminophoric material, may be disposed over solid state emitters in a solid state emitter package. Multiple solid state emitters may be provided in a single package. A package including multiple solid state emitters may include at least one of the following: a single leadframe arranged to conduct power to the solid state emitters, a single reflector arranged to reflect at least a portion of light emanating from each solid state emitter, a single submount supporting each solid state emitter, and a single lens arranged to transmit at least a portion of light emanating from each solid state emitter. Individual LEDs or groups of LEDs in a solid state package (e.g., wired in series) may be separately controlled. As depicted schematically in
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(20) The light emitted by a light source may be represented by a point on a chromaticity diagram, such as the 1931 CIE chromaticity diagram, having color coordinates denoted (ccx, ccy) on the X-Y axes of the diagram. A region on a chromaticity diagram may represent light sources having similar chromaticity coordinates.
(21) The ability of a light source to accurately reproduce color in illuminated objects is typically characterized using the color rendering index (CRI), also referred to as the CIE Ra value. The Ra value of a light source is a modified average of the relative measurements of how the color rendition of an illumination system compares to that of a reference black-body radiator or daylight spectrum when illuminating eight reference colors R1-R8. Thus, the Ra value is a relative measure of the shift in surface color of an object when lit by a particular lamp. The Ra value equals 100 if the color coordinates of a set of test colors being illuminated by the illumination system are the same as the coordinates of the same test colors being irradiated by a reference light source of equivalent CCT. For CCTs less than 5000K, the reference illuminants used in the CRT calculation procedure are the SPDs of blackbody radiators; for CCTs above 5000K, imaginary SPDs calculated from a mathematical model of daylight are used. These reference sources were selected to approximate incandescent lamps and daylight, respectively. Daylight generally has an Ra value of nearly 100, incandescent bulbs have an Ra value of about 95, fluorescent lighting typically has an Ra value of about 70 to 85, while monochromatic light sources have an Ra value of essentially zero. Light sources for general illumination applications with an Ra value of less than 50 are generally considered very poor and are typically only used in applications where economic issues preclude other alternatives. The calculation of CIE Ra values is described more fully in Commission Internationale de l'Eclairage. 1995. Technical Report: Method of Measuring and Specifying Colour Rendering Properties of Light Sources, CIE No. 13.3-1995. Vienna, Austria: Commission Internationale de l'Eclairage, which is incorporated by reference herein in its entirety for all purposes. In addition to the Ra value, a light source can also be evaluated based on a measure of its ability to render a saturated red reference color R9, also known as test color sample 9 (TCS09), with the R9 color rendering value (R9 value). Light sources can also be evaluated based on a measure of ability to render additional colors R10-R15, which include realistic colors like yellow, green, blue, Caucasian skin color (R13), tree leaf green, and Asian skin color (R15), respectively. Light sources can further be evaluated by calculating the gamut area index (GAI). Connecting the rendered color points from the determination of the CIE Ra value in two dimensional space will form a gamut area. Gamut area index is calculated by dividing the gamut area formed by the light source with the gamut area formed by a reference source using the same set of colors that are used for CRT. GAI uses an Equal Energy Spectrum as the reference source rather than a black body radiator. A gamut area index related to a black body radiator (GAIBB) can be calculated by using the gamut area formed by the blackbody radiator at the equivalent CCT to the light source.
(22) The ability of a light source to accurately reproduce color in illuminated objects can be characterized using the metrics described in IES Method for Evaluating Light Source Color Rendition, Illuminating Engineering Society, Product ID: TM-30-15 (referred to herein as the TM-30-15 standard), which is incorporated by reference herein in its entirety for all purposes. The TM-30-15 standard describes metrics including the Fidelity Index (Rf) and the Gamut Index (Rg) that can be calculated based on the color rendition of a light source for 99 color evaluation samples (CES). The 99 CES provide uniform color space coverage, are intended to be spectral sensitivity neutral, and provide color samples that correspond to a variety of real objects. Rf values range from 0 to 100 and indicate the fidelity with which a light source renders colors as compared with a reference illuminant. Rg values provide a measure of the color gamut that the light source provides relative to a reference illuminant. The range of Rg depends upon the Rf value of the light source being tested. The reference illuminant is selected depending on the CCT. For CCT values less than or equal to 4500K, Planckian radiation is used. For CCT values greater than or equal to 5500K, CIE Daylight illuminant is used. Between 4500K and 5500K a proportional mix of Planckian radiation and the CIE Daylight illuminant is used, according to the following equation:
(23)
where T.sub.t is the CCT value, S.sub.r,M(, T.sub.t) is the proportional mix reference illuminant, S.sub.r,P(, T.sub.t) is Planckian radiation, and S.sub.r,D(, T.sub.t) is the CIE Daylight illuminant.
(24) The ability of a light source to provide illumination that allows for the clinical observation of cyanosis is based upon the light source's spectral power density in the red portion of the visible spectrum, particularly around 660 nm. The cyanosis observation index (COI) is defined by AS/NZS 1680.2.5 Interior Lighting Part 2.5: Hospital and Medical Tasks, Standards Australia, 1997 which is incorporated by reference herein in its entirety, including all appendices, for all purposes. COI is applicable for CCTs from about 3300K to about 5500K, and is preferably of a value less than about 3.3. If a light source's output around 660 nm is too low a patient's skin color may appear darker and may be falsely diagnosed as cyanosed. If a light source's output at 660 nm is too high, it may mask any cyanosis, and it may not be diagnosed when it is present. COI is a dimensionless number and is calculated from the spectral power distribution of the light source. The COI value is calculated by calculating the color difference between blood viewed under the test light source and viewed under the reference lamp (a 4000 K Planckian source) for 50% and 100% oxygen saturation and averaging the results. The lower the value of COI, the smaller the shift in color appearance results under illumination by the source under consideration.
(25) Circadian illuminance (CLA) is a measure of circadian effective light, spectral irradiance distribution of the light incident at the cornea weighted to reflect the spectral sensitivity of the human circadian system as measured by acute melatonin suppression after a one-hour exposure, and CS, which is the effectiveness of the spectrally weighted irradiance at the cornea from threshold (CS=0.1) to saturation (CS=0.7). The values of CLA are scaled such that an incandescent source at 2856K (known as CIE Illuminant A) which produces 1000 lux (visual lux) will produce 1000 units of circadian lux (CLA). CS values are transformed CLA values and correspond to relative melotonian suppression after one hour of light exposure for a 2.3 mm diameter pupil during the mid-point of melotonian production. CS is calculated from
(26)
The calculation of CLA is more fully described in Rea et al., Modelling the spectral sensitivity of the human circadian system, Lighting Research and Technology, 2011; 0: 1-12, and Figueiro et al., Designing with Circadian Stimulus, October 2016, LD+A Magazine, Illuminating Engineering Society of North America, which are incorporated by reference herein in its entirety for all purposes. Figueiro et al. describe that exposure to a CS of 0.3 or greater at the eye, for at least one hour in the early part of the day, is effective for stimulating the circadian system and is associated with better sleep and improved behavior and mood.
(27) In some aspects the present disclosure relates to lighting devices and methods to provide light having particular vision energy and circadian energy performance. Many figures of merit are known in the art, some of which are described in Ji Hye Oh, Su Ji Yang and Young Rag Do, Healthy, natural, efficient and tunable lighting: four-package white LEDs for optimizing the circadian effect, color quality and vision performance, Light: Science & Applications (2014) 3: e141-e149, which is incorporated herein in its entirety, including supplementary information, for all purposes. Luminous efficacy of radiation (LER) can be calculated from the ratio of the luminous flux to the radiant flux (S()), i.e. the spectral power distribution of the light source being evaluated, with the following equation:
(28)
Circadian efficacy of radiation (CER) can be calculated from the ratio of circadian luminous flux to the radiant flux, with the following equation:
(29)
Circadian action factor (CAF) can be defined by the ratio of CER to LER, with the following equation:
(30)
The term blm refers to biolumens, units for measuring circadian flux, also known as circadian lumens. The term lm refers to visual lumens. V() is the photopic spectral luminous efficiency function and C() is the circadian spectral sensitivity function. The calculations herein use the circadian spectral sensitivity function, C(), from Gall et al., Proceedings of the CIE Symposium 2004 on Light and Health: Non-Visual Effects, 30 Sep.-2 Oct. 2004; Vienna, Austria 2004. CIE: Wien, 2004, pp 129-132, which is incorporated herein in its entirety for all purposes. By integrating the amount of light (milliwatts) within the circadian spectral sensitivity function and dividing such value by the number of photopic lumens, a relative measure of melatonin suppression effects of a particular light source can be obtained. A scaled relative measure denoted as melatonin suppressing milliwatts per hundred lumens may be obtained by dividing the photopic lumens by 100. The term melatonin suppressing milliwatts per hundred lumens consistent with the foregoing calculation method is used throughout this application and the accompanying figures and tables.
(31) In some exemplary implementations, the present disclosure provides semiconductor light emitting devices 100 that include a plurality of LED strings, with each LED string having a recipient luminophoric medium that comprises a luminescent material. The LED(s) in each string and the luminophoric medium in each string together emit an unsaturated light having a color point within a color range in the 1931 CIE chromaticity diagram. A color range in the 1931 CIE chromaticity diagram refers to a bounded area defining a group of color coordinates (ccx, ccy).
(32) In some implementations, three LED strings (101A/101B/101C) are present in a device 100, and the LED strings can have recipient luminophoric mediums (102A/102B/102C). A first LED string 101A and a first luminophoric medium 102A together can emit a first light having a first color point within a white color range. The combination of the first LED string 101A and the first luminophoric medium 102A are also referred to herein as a white channel. A second LED string 101B and a second luminophoric medium 102B together can emit a second light having a second color point within a red color range. The combination of the second LED string 101B and the second luminophoric medium 102B are also referred to herein as a red channel. A third LED string 101C and a third luminophoric medium 102C together can emit a third light having a third color point within a cyan color range. The combination of the third LED string 101C and the third luminophoric medium 102C are also referred to herein as a cyan channel. The first, second, and third LED strings 101A/101B/101C can be provided with independently applied on-state drive currents in order to tune the intensity of the first, second, and third unsaturated light produced by each string and luminophoric medium together. By varying the drive currents in a controlled manner, the color coordinate (ccx, ccy) of the total light that is emitted from the device 100 can be tuned. In some implementations, white light can be generated in modes that only produce light from one or two of the LED strings. In one implementation, white light is generated using only the first and second LED strings, i.e. the white and red channels. In another implementation, white light is generated using only the first and third LED strings, i.e., the white and cyan channels. In some implementations, only one of the LED strings, the white channel, is producing light during the generation of white light, as the other two LED strings are not necessary to generate white light at the desired color point with the desired color rendering performance. Some aspects of some suitable white channel components and red channel components have been described in International Patent Application Nos. PCT/US2017/047230, PCT/US2017/047231, and PCT/US2017/047233 filed Aug. 16, 2017, the entireties of which are incorporated herein for all purposes.
(33)
(34) In some implementations, suitable color ranges can be narrower than those depicted in
(35) The LEDs in the white channel can produce color points within acceptable color ranges 304A, 402, 304B, and 304C. White color range 304A can be defined by a polygonal region on the 1931 CIE Chromaticity Diagram defined by the following ccx, ccy color coordinates: (0.4006, 0.4044), (0.3736, 0.3874), (0.3670, 0.3578), (0.3898, 0.3716), which correlates to an ANSI C78.377-2008 standard 4000K nominal CCT white light with target CCT and tolerance of 3985275K and target duv and tolerance of 0.0010.006, as more fully described in American National Standard ANSI C78.377-2008, Specifications for the Chromaticity of Solid State Lighting Products, National Electrical Manufacturers Association, American National Standard Lighting Group, which is incorporated herein in its entirety for all purposes. In some implementations, suitable white color ranges can be described as MacAdam ellipse color ranges in the 1931 CIE Chromaticity Diagram color space, as illustrated schematically in
(36) In some implementations, the LEDs in the first, second and third LED strings can be LEDs with peak emission wavelengths at or below about 535 nm. In some implementations, the LEDs emit light with peak emission wavelengths between about 360 nm and about 535 nm. In some implementations, the LEDs in the first, second and third LED strings can be formed from InGaN semiconductor materials. In some preferred implementations, the first, second, and third LED strings can have LEDs having a peak wavelength between about 405 nm and about 485 nm. In some implementations, the third LED string can have LEDs having a peak wavelength between about 440 nm and about 465 nm. The LEDs used in the first, second and third LED strings may have full-width half-maximum wavelength ranges of between about 10 nm and about 30 nm. In some preferred implementations, the first, second, and third LED strings can include one or more LUXEON Z Color Line royal blue LEDs (product code LXZ1-PR01) of color bin codes 3, 4, 5, or 6 or one or more LUXEON Z Color Line blue LEDs (LXZ1-PB01) of color bin code 1 or 2 (Lumileds Holding B.V., Amsterdam, Netherlands). In certain preferred implementations, the third LED string can include one or more LUXEON royal blue LEDs (product code LXML-PR01 and LXML-PRO2) of color bins 3, 4, 5, or 6. The wavelength information for these color bins is provided in Table 1. Similar LEDs from other manufacturers such as OSRAM GmbH and Cree, Inc. could also be used, provided they have peak emission and full-width half-maximum wavelengths of the appropriate values.
(37) TABLE-US-00001 TABLE 1 Dominant/Peak Wavelength (nm) Part Number Bin Minimum Maximum LXZ1-PB01 1 460 465 2 465 470 5 480 485 LXZ1-PR01 3 440 445 LXML-PR01 4 445 450 LXML-PR02 5 450 455 6 455 460
(38) In implementations utilizing LEDs that emit substantially saturated light at wavelengths between about 360 nm and about 535 nm, the device 100 can include suitable recipient luminophoric mediums for each LED in order to produce light having color points within the suitable red color ranges 302A-C, cyan color ranges 303A-D, and white color ranges 304A-C described herein. The light emitted by each LED string, i.e., the light emitted from the LED(s) and associated recipient luminophoric medium together, can have a spectral power distribution (SPD) having spectral power with ratios of power across the visible wavelength spectrum from about 380 nm to about 780 nm. While not wishing to be bound by any particular theory, it is speculated that the use of such LEDs in combination with recipient luminophoric mediums to create unsaturated light within the suitable color ranges 302A-C, 303A-D, and 304A-C provides for improved color rendering performance for white light across a predetermined range of CCTs from a single device 100. Some suitable ranges for spectral power distribution ratios of the light emitted by the LED strings (101B/101C) and recipient luminophoric mediums (102B/102C) together in the red and cyan channels are shown in Table 2. The table shows the ratios of spectral power within wavelength ranges, with an arbitrary reference wavelength range selected for each color range and normalized to a value of 100.0. Table 2 also shows suitable minimum and maximum values for the spectral intensities within various ranges relative to the normalized range with a value of 100.0, for the color points within the cyan and red color ranges. While not wishing to be bound by any particular theory, it is speculated that because the spectral power distributions for generated light with color points within the cyan and red color ranges contains higher spectral intensity across visible wavelengths as compared to lighting apparatuses and methods that utilize more saturated colors, this allows for improved color rendering for test colors other than R1-R8. In some implementations, the red channel can have a spectral power distribution with spectral power in one or more of the wavelength ranges other than the arbitrary reference wavelength range increased or decreased within 30% greater or less, within 20% greater or less, within 10% greater or less, or within 5% greater or less than the values of a red channel shown in Table 2. In some implementations, the cyan channel can have a spectral power distribution with spectral power in one or more of the wavelength ranges other than the arbitrary reference wavelength range increased or decreased within 30% greater or less, within 20% greater or less, within 10% greater or less, or within 5% greater or less than the values of the cyan channel shown in Table 2.
(39) TABLE-US-00002 TABLE 2 Relative Spectral Power Distribution in 380-780 nm wavelength bins Combined color 380 < 420 < 460 < 500 < 540 < 580 < 620 < 660 < 700 < 740 < Channel point (ccx, ccy) 420 460 500 540 580 620 660 700 740 780 Red 1 (0.5842, 0.3112) 0.0 9.6 2.0 1.4 9.0 48.5 100.0 73.1 29.5 9.0 Red 2 (0.5842, 0.3112) 0.0 157.8 2.0 1.4 9.0 48.5 100.0 73.1 29.5 9.0 Red 3 (0.5702, 0.3869) 0.7 2.1 4.1 12.2 20.5 51.8 100.0 74.3 29.3 8.4 Red 4 (0.5563, 0.3072) 14.8 10.5 6.7 8.7 8.7 102.8 100.0 11.0 1.5 1.1 Red 5 (0.5941, 0.3215) 0.2 8.5 3.0 5.5 9.5 60.7 100.0 1.8 0.5 0.3 Red 6 (0.5842, 0.3112) 0.7 2.1 4.1 12.2 20.5 51.8 100.0 74.3 29.3 8.4 Red 7 (0.5735, 0.3007) 0.0 2.3 5.0 10.2 24.7 61.0 100.0 71.7 27.8 8.4 Red 8 (0.5700, 0.3870) 0.1 2.7 4.3 9.5 24.6 60.4 100.0 51.5 12.4 2.4 Red 9 (0.5932, 0.3903) 0.2 1.4 0.7 7.3 22.3 59.8 100.0 61.2 18.1 4.9 Red 0.0 2.1 2.0 1.4 8.7 48.5 100.0 1.8 0.5 0.3 Minimum Red 14.8 157.8 6.7 12.2 24.7 102.8 100.0 74.3 29.5 9.0 Maximum Cyan 1 (0.3730, 0.4978) 0.72 15.92 33.52 98.19 100.00 68.55 47.06 22.12 6.30 1.65 Cyan Range 1 3.9 100.0 112.7 306.2 395.1 318.2 245.0 138.8 39.5 10.3 Minimum Cyan Range 1 130.6 100.0 553.9 5472.8 9637.9 12476.9 13285.5 6324.7 1620.3 344.7 Maximum Cyan Range 2 3.9 100.0 112.7 306.2 395.1 318.2 245.0 138.8 39.5 10.3 Minimum Cyan Range 2 130.6 100.0 553.9 2660.6 4361.9 3708.8 2223.8 712.2 285.6 99.6 Maximum
(40) Blends of luminescent materials can be used in luminophoric mediums (102A/102B/102C) to create luminophoric mediums having the desired saturated color points when excited by their respective LED strings (101A/101B/101C) including luminescent materials such as those disclosed in co-pending applications PCT/US2016/015318 filed Jan. 28, 2016, entitled Compositions for LED Light Conversions, and PCT/US2016/015473 filed Jan. 28, 2016, entitled Illuminating with a Multizone Mixing Cup, the entirety of which are hereby incorporated by this reference as if fully set forth herein. Traditionally, a desired combined output light can be generated along a tie line between the LED string output light color point and the saturated color point of the associated recipient luminophoric medium by utilizing different ratios of total luminescent material to the encapsulant material in which it is incorporated. Increasing the amount of luminescent material in the optical path will shift the output light color point towards the saturated color point of the luminophoric medium. In some instances, the desired saturated color point of a recipient luminophoric medium can be achieved by blending two or more luminescent materials in a ratio. The appropriate ratio to achieve the desired saturated color point can be determined via methods known in the art. Generally speaking, any blend of luminescent materials can be treated as if it were a single luminescent material, thus the ratio of luminescent materials in the blend can be adjusted to continue to meet a target CIE value for LED strings having different peak emission wavelengths. Luminescent materials can be tuned for the desired excitation in response to the selected LEDs used in the LED strings (101A/101B/101C), which may have different peak emission wavelengths within the range of from about 360 nm to about 535 nm. Suitable methods for tuning the response of luminescent materials are known in the art and may include altering the concentrations of dopants within a phosphor, for example.
(41) In some implementations of the present disclosure, luminophoric mediums can be provided with combinations of two types of luminescent materials. The first type of luminescent material emits light at a peak emission between about 515 nm and about 590 nm in response to the associated LED string emission. The second type of luminescent material emits at a peak emission between about 590 nm and about 700 nm in response to the associated LED string emission. In some instances, the luminophoric mediums disclosed herein can be formed from a combination of at least one luminescent material of the first and second types described in this paragraph. In implementations, the luminescent materials of the first type can emit light at a peak emission at about 515 nm, 525 nm, 530 nm, 535 nm, 540 nm, 545 nm, 550 nm, 555 nm, 560 nm, 565 nm, 570 nm, 575 nm, 580 nm, 585 nm, or 590 nm in response to the associated LED string emission. In preferred implementations, the luminescent materials of the first type can emit light at a peak emission between about 520 nm to about 555 nm. In implementations, the luminescent materials of the second type can emit light at a peak emission at about 590 nm, about 595 nm, 600 nm, 605 nm, 610 nm, 615 nm, 620 nm, 625 nm, 630 nm, 635 nm, 640 nm, 645 nm, 650 nm, 655 nm, 670 nm, 675 nm, 680 nm, 685 nm, 690 nm, 695 nm, or 700 nm in response to the associated LED string emission. In preferred implementations, the luminescent materials of the first type can emit light at a peak emission between about 600 nm to about 670 nm.
(42) Some exemplary luminescent materials of the first and second type are disclosed elsewhere herein and referred to as Compositions A-F. Table 3 shows aspects of some exemplar luminescent materials and properties:
(43) TABLE-US-00003 TABLE 3 Suitable Ranges Exemplary Emission Embodiment Peak FWHM Density Emission FWHM Range Range Designator Exemplars Material(s) (g/mL) Peak (nm) (nm) (nm) (nm) Composition Luag: Cerium doped 6.73 535 95 530-540 90-100 A luletium aluminum garnet (Lu.sub.3Al.sub.5O.sub.12) Composition Yag: Cerium doped 4.7 550 110 545-555 105-115 B yttrium aluminum garnet (Y.sub.3Al.sub.5O.sub.12) Composition a 650 nm-peak 3.1 650 90 645-655 85-95 C wavelength emission phosphor: Europium doped calcium aluminum silica nitride (CaAlSiN.sub.3) Composition a 525 nm-peak 3.1 525 60 520-530 55-65 D wavelength emission phosphor: GBAM: BaMgAl.sub.10O.sub.17:Eu Composition a 630 nm-peak 5.1 630 40 625-635 35-45 E wavelength emission quantum dot: any semiconductor quantum dot material of appropriate size for desired emission wavelengths Composition a 610 nm-peak 5.1 610 40 605-615 35-45 F wavelength emission quantum dot: any semiconductor quantum dot material of appropriate size for desired emission wavelengths Matrix M Silicone binder 1.1 mg/mm.sup.3
(44) Blends of Compositions A-F can be used in luminophoric mediums (102A/102B/102C) to create luminophoric mediums having the desired saturated color points when excited by their respective LED strings (101A/101B/101C). In some implementations, one or more blends of one or more of Compositions A-F can be used to produce luminophoric mediums (102A/102B/102C). In some preferred implementations, one or more of Compositions A, B, and D and one or more of Compositions C, E, and F can be combined to produce luminophoric mediums (102A/102B/102C). In some preferred implementations, the encapsulant for luminophoric mediums (102A/102B/102C) comprises a matrix material having density of about 1.1 mg/mm.sup.3 and refractive index of about 1.545 or from about 1.4 to about 1.6. In some implementations, Composition A can have a refractive index of about 1.82 and a particle size from about 18 micrometers to about 40 micrometers. In some implementations, Composition B can have a refractive index of about 1.84 and a particle size from about 13 micrometers to about 30 micrometers. In some implementations, Composition C can have a refractive index of about 1.8 and a particle size from about 10 micrometers to about 15 micrometers. In some implementations, Composition D can have a refractive index of about 1.8 and a particle size from about 10 micrometers to about 15 micrometers. Suitable phosphor materials for Compositions A, B, C, and D are commercially available from phosphor manufacturers such as Mitsubishi Chemical Holdings Corporation (Tokyo, Japan), Intematix Corporation (Fremont, CA), EMD Performance Materials of Merck KGaA (Darmstadt, Germany), and PhosphorTech Corporation (Kennesaw, GA). In some implementations, a set of suitable materials for Compositions A-F and Matrix M can be selected, as shown in Table 4 as Model 1. In other implementations, a set of suitable materials for Compositions A-F and Matrix M can be selected, as shown in Table 4 as Model 2.
(45) TABLE-US-00004 TABLE 4 Model 1 particle refrac- Model 2 Exemplars size tive particle refractive Designator Material(s) (d50) index size index Composition Luag: Cerium 18.0 m 1.84 40 m 1.8 A doped lutetium aluminum garnet (Lu.sub.3Al.sub.5O.sub.12) Composition Yag: Cerium 13.5 m 1.82 30 m 1.85 B doped yttrium aluminum garnet (Y.sub.3Al.sub.5O.sub.12) Composition a 650 nm-peak 15.0 m 1.8 10 m 1.8 C wavelength emission phosphor: Europium doped calcium aluminum silica nitride (CaAlSiN.sub.3) Composition a 525 nm-peak 15.0 m 1.8 n/a n/a D wavelength emission phosphor: GBAM: BaMgAl.sub.10O.sub.17:Eu Composition a 630 nm-peak 10.0 nm 1.8 n/a n/a E wavelength emission quantum dot: any semiconductor quantum dot material of appropriate size for desired emission wavelengths Composition a 610 nm-peak 10.0 nm 1.8 n/a n/a F wavelength emission quantum dot: any semiconductor quantum dot material of appropriate size for desired emission wavelengths Matrix M Silicone binder 1.545 1.545
(46) In some aspects, the present disclosure provides semiconductor light emitting devices 100 that can have a plurality of light emitting diode (LED) strings. Each LED string can have one, or more than one, LED. As depicted schematically in
(47) In some aspects, the present disclosure provides semiconductor light emitting devices capable to producing tunable white light through a range of CCT values. In some implementations, devices can output white light at color points along a predetermined path within a 7-step MacAdam ellipse around any point on the black body locus having a correlated color temperature between about 1800K and about 3200K. In further implementations, devices can output white light at color points along a predetermined path shifted 72 DUV from the black body locus having a correlated color temperature between about 1800K and about 3200K. In some implementations, the devices can generate white light corresponding to a plurality of points along a predefined path with the light generated at each point having light with one or more of Ra greater than or equal to about 90, R9 greater than or equal to about 55, and GAIBB greater than or equal to about 95. In some preferred implementations, the devices of the present disclosure can generate white light so that it falls within a 7-step MacAdam ellipse around any point on the black body locus having a correlated color temperature between about 1800K and about 3000K, and generate the fifth unsaturated light corresponding to a plurality of points along a predefined path with the light generated at each point having light with one or more of Ra greater than or equal to about 90, R9 greater than or equal to about 75, and GAIBB greater than or equal to about 95. In some implementations the devices of the present disclosure comprise a drive circuit is configured to adjust the fourth color point so that it falls within a 7-step MacAdam ellipse around any point on the black body locus having a correlated color temperature between about 1800K and about 3200K, and in some of these implementations the light emitting devices are configured to generate the fourth unsaturated light corresponding to a plurality of points along a predefined path with the light generated at each point having light with one or more of Ra greater than or equal to about 90 and R9 greater than or equal to about 55, one or more of Rf greater than or equal to 75, Rf greater than or equal to about 80, Rf greater than or equal to about 90, Rf greater than about 95, Rf equal to about 100, Rg greater than or equal to about 80 and less than or equal to about 120, Rg greater than or equal to about 90 and less than or equal to about 110, Rg greater than or equal to about 95 and less than or equal to about 105, or Rg equal to about 100. In some implementations the devices comprise a drive circuit configured to adjust the fourth color point so that it falls within a 7-step MacAdam ellipse around any point on the black body locus having a correlated color temperature between about 1800K and about 3000K, and the light emitting devices are configured to generate the fourth unsaturated light corresponding to a plurality of points along a predefined path with the light generated at each point having light with one or more of Ra greater than or equal to about 90 and R9 greater than or equal to about 60. In some implementations the devices comprise a drive circuit configured to adjust the fourth color point so that it falls within a 7-step MacAdam ellipse around any point on the black body locus having a correlated color temperature between about 2000K and about 3200K, and the light emitting devices are configured to generate the fourth unsaturated light corresponding to a plurality of points along a predefined path with the light generated at each point having light with one or more of Rf greater than or equal to about 80, Rf greater than or equal to about 90, Rf greater than about 95, Rf equal to about 100, Rg greater than or equal to about 80 and less than or equal to about 120, Rg greater than or equal to about 85 and less than or equal to about 115; Rg greater than or equal to about 90 and less than or equal to about 110, Rg greater than or equal to about 95 and less than or equal to about 105, or Rg equal to about 100. In further implementations the devices comprise a drive circuit configured to adjust the fourth color point so that it falls within a 7-step MacAdam ellipse around any point on the black body locus having a correlated color temperature between about 1800K and about 3200K, and the light emitting devices are configured to generate the fourth unsaturated light corresponding to a plurality of points along a predefined path, with the light generated at points along about 85% of the predefined path has Ra greater than or equal to about 90, the light generated at points along about 85% of the predefined path has R9 greater than or equal to about 65, or both.
EXAMPLES
General Simulation Method
(48) Devices having a plurality of LED strings with particular color points were simulated. For each device, LED strings and recipient luminophoric mediums with particular emissions were selected, and then white light rendering capabilities were calculated for a select number of representative points on or near the Planckian locus between about 1800K and about 3200K. Ra, R9, R13, R15, LER, Rf, Rg, CLA, and CS performance values were calculated at each representative point, and COI values were calculated for representative points near the CCT range of about 3200K.
(49) The calculations were performed with Scilab (Scilab Enterprises, Versailles, France), LightTools (Synopsis, Inc., Mountain View, CA), and custom software created using Python (Python Software Foundation, Beaverton, OR). Each LED string was simulated with an LED emission spectrum and excitation and emission spectra of luminophoric medium(s). For luminophoric mediums comprising phosphors, the simulations also included the absorption spectrum and particle size of phosphor particles. The LED strings generating combined emissions within white, red, and cyan color regions were prepared using spectra of a LUXEON Z Color Line royal blue LED (product code LXZ1-PR01) of color bin codes 3, 4, 5, or 6, a LUXEON Z Color Line blue LED (LXZ1-PB01) of color bin code 1 or 2, and LUXEON Rebel Royal Blue LED (product code LXML-PRO1 or LXML-PRO2) of color bin code 3, 4, 5, or 6 (Lumileds Holding B.V., Amsterdam, Netherlands). Similar LEDs from other manufacturers such as OSRAM GmbH and Cree, Inc. could also be used.
(50) The emission, excitation and absorption curves are available from commercially available phosphor manufacturers such as Mitsubishi Chemical Holdings Corporation (Tokyo, Japan), Intematix Corporation (Fremont, CA), EMD Performance Materials of Merck KGaA (Darmstadt, Germany), and PhosphorTech Corporation (Kennesaw, GA). The luminophoric mediums used in the LED strings were combinations of one or more of Compositions A, B, and D and one or more of Compositions C, E, and F as described more fully elsewhere herein. Those of skill in the art appreciate that various combinations of LEDs and luminescent blends can be combined to generate combined emissions with desired color points on the 1931 CIE chromaticity diagram and the desired spectral power distributions.
Example 1
(51) A semiconductor light emitting device was simulated having three LED strings. A first LED string is driven by a blue LED having peak emission wavelength of approximately 450 nm to approximately 455 nm, utilizes a recipient luminophoric medium, and generates a combined emission of a white color point of (0.3818, 0.3797). A second LED string is driven by a blue LED having peak emission wavelength of approximately 450 nm to approximately 455 nm, utilizes a recipient luminophoric medium, and generates a combined emission of a red color point with a 1931 CIE chromaticity diagram color point of (0.5932, 0.3903). A third LED string is driven by a blue LED having peak emission wavelength of approximately 450 nm to approximately 455 nm, utilizes a recipient luminophoric medium, and generates a combined emission of a cyan color point with a 1931 CIE chromaticity diagram color point of (0.373, 0.4978).
(52) Tables 5 and 6 below shows the spectral power distributions for the red and cyan color points generated by the device of this Example, with spectral power shown within wavelength ranges in nanometers from 380 nm to 780 nm, with an arbitrary reference wavelength range selected for each color range and normalized to a value of 100.0. Table 7 shows color-rendering and circadian performance characteristics of the device for a representative selection of white light color points near the Planckian locus.
(53) TABLE-US-00005 TABLE 5 380 < 420 < 460 < 500 < 540 < 580 < 620 < 660 < 700 < 740 < 420 460 500 540 580 620 660 700 740 780 Red 0.2 1.4 0.7 7.3 22.3 59.8 100.0 61.2 18.1 4.9 Cyan 0.7 15.9 33.5 98.2 100.0 68.6 47.1 22.1 6.3 1.7
(54) TABLE-US-00006 TABLE 6 380 < 400 < 420 < 440 < 460 < 480 < 500 < 520 < 540 < 560 < 580 < 400 420 440 460 480 500 520 540 560 580 600 Red 0.0 0.3 1.4 1.3 0.4 0.9 4.2 9.4 15.3 26.4 45.8 Cyan 0.2 1.2 8.1 22.2 17.5 46.3 88.2 98.5 100.0 90.2 73.4 600 < 620 < 640 < 660 < 680 < 700 < 720 < 740 < 760 < 780 < 620 640 660 680 700 720 740 760 780 800 Red 66.0 87.0 100.0 72.5 42.0 22.3 11.6 6.1 3.1 0.0 Cyan 57.0 48.1 41.4 27.0 15.1 7.9 4.0 2.1 1.0 0.0
(55) TABLE-US-00007 White Cyan Red Channel Channel Channel Relative Relative Relative CCT duv Intensity Intensity Intensity Ra R9 ccx ccy Rf Rg COI R13 R15 LER CLA CS 3200 0.53 0.57 0.22 0.21 89.9 59.6 0.424 0.4005 88 102 2.42 90.1 87.3 296.5 1007 0.531 3102 0.31 0.52 0.24 0.24 90.8 63.8 0.4303 0.4024 89 102 2.82 91.2 88.6 292.8 977 0.527 3001 0.04 0.47 0.26 0.27 91.7 67.7 0.4368 0.4039 89 102 3.42 92.2 89.9 288.9 946 0.522 2903 0.39 0.42 0.28 0.30 92.6 71.7 0.4446 0.4075 90 102 93.3 91.0 285.3 909 0.516 2801 0.31 0.37 0.30 0.33 93.5 75.1 0.4522 0.4095 91 103 94.3 92.1 281.1 873 0.510 2702 0.68 0.32 0.31 0.37 94.4 78.4 0.4609 0.4126 91 103 95.3 93.0 276.9 833 0.503 2599 0.1 0.27 0.32 0.41 95.0 80.1 0.4681 0.412 91 104 96.2 93.8 272.0 801 0.497 2509 0.66 0.23 0.33 0.44 95.7 82.5 0.4774 0.4156 92 103 97.0 94.4 268.1 758 0.488 2403 0.46 0.18 0.33 0.48 96.3 83.5 0.4867 0.4161 92 103 97.7 94.9 262.9 717 0.479 2296 0.09 0.14 0.33 0.52 96.6 83.4 0.4959 0.4149 92 104 98.3 95.0 257.2 677 0.469 2203 0.18 0.11 0.33 0.57 96.7 82.9 0.5049 0.4146 91 104 98.6 94.9 252.1 636 0.459 2099 0.19 0.07 0.32 0.61 96.8 81.9 0.5165 0.4152 92 103 98.7 94.5 246.4 585 0.444 2010 0.28 0.04 0.30 0.66 96.4 79.4 0.525 0.4126 90 104 98.5 93.8 241.0 547 0.431 1902 0.37 0.01 0.27 0.72 95.8 75.6 0.5366 0.4101 89 103 97.7 92.4 234.3 494 0.413 1797 0.12 0.00 0.23 0.77 94.9 70.8 0.5493 0.4078 88 102 96.5 90.5 227.6 436 0.389
(56) Table 8 shows exemplary luminophoric mediums suitable for the recipient luminophoric mediums for the red channels of this Example, using the Compositions A-F from Model 1 or Model 2 as described in Tables 3 and 4.
(57) TABLE-US-00008 TABLE 8 Volumetric Ratios - Using Model 1 Compositions from Tables 3 and 4 Comp. Comp. Comp Comp. Comp. Comp. A B C D E F Matrix Red 13.99 26.57 59.44 Blend 1 Red 17.20 8.94 73.86 Blend 2 Red 20.56 18.38 0.02 61.04 Blend 3 Red 5.55 9.40 22.00 63.05 Blend 4 Red 2.47 29.16 47.28 21.08 Blend 5
(58) Light rendering properties were calculated for commercially available tunable white light systems. Table 9 shows color-rendering and circadian performance characteristics of a three-channel device having white, green, and red channels, LED Engin's LuxiTune Tunable White Light Engine For Halogen-style Dimming LTC-83T1xx-0HD1 (LED Engin, Inc., San Jose, CA), for a representative selection of white light color points near the Planckian locus. Table 10 shows color-rendering and circadian performance characteristics of a five-channel device having white, blue, red, lime, and amber channels, Lumenetix's Araya Color Tuning Module (CTM) (Lumenetix, Scotts Valley, CA), for a representative selection of white light color points near the Planckian locus.
(59) TABLE-US-00009 TABLE 9 circadian power circadian CCT duv Ra R9 Rf Rg [mW] flux CER CAF EML CLA CS 2957.1 0.99 88.14 60.12 87 109 0.001 0.0003 113.4262 0.3585 0.49788 914 0.517 2832.5 1.11 87.55 58.33 87 109 0.001 0.0002 106.4456 0.3361 0.4747 868 0.509 2741.4 0.58 87.23 58.96 87 110 0.001 0.0002 99.9416 0.3140 0.45283 824 0.501 2608.7 0.52 86.92 60.56 86 111 0.001 0.0002 92.4105 0.2885 0.42649 772 0.491 2506.3 0.26 86.69 62.57 86 111 0.001 0.0001 85.8899 0.2670 0.40442 727 0.481 2303.2 0.25 85.21 65.65 85 112 0.000 0.0001 74.0231 0.2303 0.36621 652 0.463 2040.7 2.87 80.84 66.23 80 106 0.000 0.0000 64.8177 0.2083 0.33513 595 0.447 1901.4 3.36 79.19 71.22 77 118 0.000 0.0000 58.1408 0.1897 0.31196 552 0.433 1782.2 1.95 82.13 92.16 78 99 0.000 0.0000 39.1467 0.1230 0.24983 425 0.384
(60) TABLE-US-00010 TABLE 10 circadian power circadian CCT duv Ra R9 Rf Rg [mW] flux CER CAF EML CLA CS 2977 0.25 96.09 90.52 93 104 0.001 0.0003 116.7513 0.3865 0.55372 1011 0.532 2872 1.82 96.90 96.13 94 104 0.001 0.0003 111.6608 0.3787 0.54171 991 0.529 2744 1.99 97.00 88.16 93 103 0.001 0.0002 104.3151 0.3520 0.50898 929 0.52 2560 0.56 96.61 89.42 93 104 0.001 0.0001 90.5068 0.3020 0.45693 825 0.502 2454 0.64 95.93 94.25 93 104 0.000 0.0001 84.5877 0.2838 0.43942 790 0.495 2287 1.48 95.11 93.38 90 106 0.000 0.0001 76.2707 0.2567 0.40294 722 0.48 2011 0.81 93.56 93.09 89 101 0.000 0.0000 55.2737 0.1859 0.33012 578 0.441 1834 2.10 90.64 83.00 82 90 0.000 0.0000 43.3134 0.1437 0.2831 484 0.41
(61) Tables 11 and 12 show exemplary luminophoric mediums suitable for the recipient luminophoric mediums for the red channels of this Example, using the Compositions A-F from Model 1 or Model 2 as described in Tables 3 and 4.
(62) TABLE-US-00011 TABLE 11 Volumetric Ratios - Using Model 1 Compositions from Tables 3 and 4 Comp. Comp. Comp. Comp. Comp. Comp. A B C D E F Matrix Red 1.66 24.23 74.11 Blend 1 Red 0.07 15.34 7.90 76.70 Blend 2 Red 1.96 24.72 73.32 Blend 3 Red 3.43 26.48 70.10 Blend 4 Red 21.36 1.70 76.94 Blend 5 Red 0.80 24.49 1.22 73.49 Blend 6 Red 0.22 12.74 11.75 75.28 Blend 7
(63) TABLE-US-00012 TABLE 12 Volumetric Ratios - Using Model 2 Compositions from Tables 3 and 4 Comp. Comp. Comp. Comp. Comp. Comp. A B C D E F Matrix Red 0 0.58 16.23 83.19 Blend 8 Red 0.42 0 16.63 82.95 Blend 9 Red 1.79 3.09 17.6 77.52 Blend 10
Example 4
(64) Exemplary luminophoric mediums suitable for the recipient luminophoric mediums for the red channels of the disclosure were modeled, using the Compositions A-F from Model 1 or Model 2 as described in Tables 3 and 4. Tables 13 and 14 show exemplary suitable luminophoric mediums that can be used in the red channels.
(65) TABLE-US-00013 TABLE 13 Volumetric Ratios - Using Model 1 Compositions from Tables 3 and 4 Comp. Comp. Comp. Comp. Comp. Comp. A B C D E F Matrix Red 11.66 21.77 66.57 Blend Red 5.59 17.46 7.21 69.74 Blend Red 13.17 25.45 61.38 Blend Red 6.47 7.75 24.90 60.88 Blend Red 16.55 8.34 75.11 Blend Red 2.37 24.60 11.89 61.13 Blend Red 4.57 16.51 12.47 66.44 Blend Red 2.18 20.26 77.55 Blend Red 0.40 13.83 5.57 80.20 Blend Red 2.57 20.93 76.50 Blend Red 0.68 2.15 22.07 75.10 Blend Red 17.50 2.11 80.40 Blend Red 1.62 20.45 0.85 77.07 Blend Red 0.47 11.38 9.48 78.67 Blend Red 2.12 26.06 71.82 Blend Red 0.24 16.36 9.03 74.37 Blend Red 2.43 26.68 70.89 Blend Red 1.02 1.64 28.61 68.72 Blend Red 22.60 2.22 75.19 Blend Red 1.11 26.37 1.45 71.07 Blend Red 0.38 13.79 12.99 72.84 Blend
(66) TABLE-US-00014 TABLE 14 Volumetric Ratios - Using Model 2 Compositions from Tables 3 and 4 Comp. Comp. Comp. Comp. Comp. Comp. A B C D E F Matrix Red 4.02 13.36 82.62 Blend Red 3.25 15.67 81.08 Blend Red 16.56 15.37 16.88 51.19 Blend Red 0.74 14.13 85.13 Blend Red 0.6 14.65 84.75 Blend Red 3.07 3.52 14.75 78.66 Blend Red 0.74 17.04 82.22 Blend Red 0.58 17.52 81.90 Blend Red 2.3 3.97 18.94 74.79 Blend
(67) Those of ordinary skill in the art will appreciate that a variety of materials can be used in the manufacturing of the components in the devices and systems disclosed herein. Any suitable structure and/or material can be used for the various features described herein, and a skilled artisan will be able to select an appropriate structures and materials based on various considerations, including the intended use of the systems disclosed herein, the intended arena within which they will be used, and the equipment and/or accessories with which they are intended to be used, among other considerations. Conventional polymeric, metal-polymer composites, ceramics, and metal materials are suitable for use in the various components. Materials hereinafter discovered and/or developed that are determined to be suitable for use in the features and elements described herein would also be considered acceptable.
(68) When ranges are used herein for physical properties, such as molecular weight, or chemical properties, such as chemical formulae, all combinations, and subcombinations of ranges for specific exemplar therein are intended to be included.
(69) The disclosures of each patent, patent application, and publication cited or described in this document are hereby incorporated herein by reference, in its entirety.
(70) Those of ordinary skill in the art will appreciate that numerous changes and modifications can be made to the exemplars of the disclosure and that such changes and modifications can be made without departing from the spirit of the disclosure. It is, therefore, intended that the appended claims cover all such equivalent variations as fall within the true spirit and scope of the disclosure.