JP2017529567A - LED light source with improved color preference using YAG, nitride and PFS phosphor - Google Patents

Abstract

Aspects of the present disclosure include one or more blue light sources having a peak wavelength in the range of about 400 nm to about 460 nm, one or more yellow-green garnet phosphors, and one or more narrow-band red light emitting downconverters. It relates to a synthetic light source. Such a synthetic light source can have an illumination preference index (LPI) of 120 or greater. In other aspects, the disclosure includes one or more blue light sources having a peak wavelength in the range of about 400 nm to about 460 nm, one or more yellow-green garnet phosphors, and one or more broadband red downconverters. It relates to a synthetic light source. In this latter aspect, the synthetic light source can have an illumination preference index (LPI) of 120 or greater. Numerous other aspects are provided. [Selection] Figure 1a

Description

  The present disclosure generally relates to providing a light source that emits light with improved color spectral characteristics such that a human observer perceives an increase in color preference.

  Reveal® refers to light sources, such as light bulbs, that General Electric Corporation has improved lighting characteristics and improved whiteness in red and green contrast compared to unimproved incandescent or halogen light sources. A trademarked term used for. Reveal® incandescent and halogen spheres are a specific type of glass (ie, glass impregnated with neodymium oxide (Nd)) before the light emitted from the filament to absorb some of the yellow light. Filter the light by placing. Glass impregnated with neodymium oxide causes a "dimple" in the yellow region of the color spectrum, so objects seen under this light, especially observers, such as people in a house, can be easily compared. Red and green objects that are capable of increasing color contrast. Also, by removing some of the yellow light through the filter, the position of chromaticity on the 1931 International Illumination de l'Eclairage (CIE) color map is slightly below the blackbody locus. Move to a point. It usually creates the impression of white light by most observers.

  The importance of yellow light and how it affects color perception is illustrated in FIGS. FIG. 1a provides a graph of three color matching functions known as XYZ tristimulus values that represent a standard observer color response. The perceived color of the object is determined by the product of the illumination source spectrum, the object reflection spectrum, and the three color matching functions. These functions relate to the photoreceptor response of the human eye and can be thought of as perception of blue (102), green (104) and red (106) light. FIG. 1b shows a graph of the product of the standard incandescent spectrum and the color matching functions for the blue (132), green (134) and red (136) responses. As can be seen, the green (134) and red (136) components are quite overlapping and the peaks are only 34 nm apart. FIG. 1c shows a graph of the product of the Reveal® incandescent spectrum and the color matching functions for the blue (162), green (164) and red (166) responses. As can be seen, the green (164) and red (166) components can be more clearly distinguished and the peak separation is 53 nm compared to the red and green components of FIG. 1b. This distinguishing feature allows the observer to more easily distinguish between red and green with high contrast, and a more saturated look when yellow light is suppressed.

  Spectrally improved lighting products have been commercially successful for decades. Traditional color metrics or traditional methods may not reward such improved lighting products, but consumers often prefer such products over similar products that have not changed . With the advent of solid state lighting (SSL), it becomes clear that current metrics are insufficient to assess and reflect the quality of LED products, especially with the customizable light emitting diode (LED) spectrum. I came. SSL light sources, such as LEDs or organic light emitting diodes (OLEDs), can generate light directly from semiconductors, such as blue or red or other colored LEDs. Alternatively, the light may be generated by converting high energy light from SSL, such as a blue or violet LED, with a down converter such as a phosphor or quantum dots or other energy conversion material. The range of peak emission wavelength of semiconductors, and the range of peak and width of emission of downconverters has been expanded by recent technological development, and now covers almost continuous range over the entire visible wavelength (about 380 nm to about 750 nm). It allows for a wide flexibility in adjusting the visible spectrum to improve the viewer's color preference.

  For nearly half a century, the Color Rendering Index (CRI) has been the main method of communicating the color of the light source. However, its effectiveness is inherently limited due to its calculation method, particularly when dealing with spectral power distributions (SPDs) that contain steep slopes with respect to wavelengths as often found in LEDs. The disadvantages of CRI are well documented and a wide variety of alternative metrics have been proposed. However, alternative color metrics have struggled to accurately quantify consumer preferences for lighting products. House, et al., “Review of measurements for light-source color rendition and considations for two-measure system for charorizing color rendition”, 104. W. Houser, M .; Wei, A .; David, M.M. R. Krames, and X. S. In Shen, a detailed review and comparison of most of the various color metrics developed was given. In general, the various metrics groups can be broken down into three broad categories related to their purpose and calculation method: fidelity, discriminability and preference. The fidelity metric includes CRI and quantifies the absolute difference from the reference light, but whether the test illuminant is perceived better or worse than the reference light, It does not consider whether it is actually preferred for most observers. The discriminant metric quantifies the total area of color space that can be displayed under the test illuminator and is maximized at extreme levels of saturation and hue distortion. Existing color preference metrics were developed to provide a quantitative unit of measure for user color preference, but all of them include observer data along with target values to enable light source optimization. Does not provide sufficient correlation. As a result, there is no metric that can be used as a target parameter in design optimization.

In general, it has been found that viewers prefer improved saturation levels that make the colors more attractive. However, high levels of saturation or hue shifts result in unnatural colors and object color rendering. For example, the gamut area index (GAI) and the gamut area scale (Q _g ) are both metrics of discrimination, but up to a certain limit of color saturation, It provides a very good correlation, but it exceeds the GAI and Q _g continues to increase, while the viewer's preference decreases rapidly. Therefore, in order to better match the viewer's preferences, I think that the color saturation metrics such GAI or Q _g is required some adjustment. In addition, observers also tend to prefer light sources that appear whiter, which depends on the chromaticity point of the illuminant relative to the full radiator (blackbody) trajectory and is somewhat independent of color saturation. As is generally recognized in the lighting industry, color preference cannot be quantified adequately by any existing color metric alone. In recent years, several attempts have been announced to better express color preference by combining two or more color metrics. However, in addition to the applicants, no one has proposed a color preference metric that defines color preference with sufficient quantitative rigor to optimize light source color preference by adjusting the spectral values. It seems not. Even if the existing existing color preference metrics are quantitative, each has limitations in some way, and optimization when designing a light source or spectrum that achieves the best color preference for a typical observer It is ineligible to use them as parameters.

Some of the well-known metrics in the Color Preference category are the Fluttery Index (R _f ), the Color Preference Index (CPI), and the Memory Color Rendering Index. MCRI). All three of these metrics have an “ideal” configuration in the chromaticity coordinates of 8-10 test color samples, each quantifying the deviation from these target values. The flattery index was the first metric for preference and used 10 color samples with unequal weighting. However, in order to maintain similarities with the color rendering index (CRI), the target chromaticity shift is reduced to one fifth of its experimental value, greatly reducing its correlation with the observer's response to color preference. It was. The CPI maintained a favorable chromaticity shift experimental value, resulting in better expression of color preference. However, CPI is very limited in its selection of test color samples that use the same 8 unsaturated test colors as CRI. Unsaturated (pastel) test colors may not be able to assess the effects of highly saturated light sources. MCRI uses the observer's memory to define an ideal chromaticity configuration for familiar objects with only 10 colors. Furthermore, none of the above metrics include the “whiteness” or chromaticity point of the test light source. In this regard, J.A. P. Freyssinier and M.M. S. Rea is the author of the book “Class A color design for light sources used in general illumination,” Journal of Light and Visual Environment, volume 37, # 2 & 3, p. 46-50 (2013) recommended a set of criteria called “Class A lighting” with constraints on CRI (> 80), GAI (80-100) and chromaticity points (close to the “white” line) . These conditions define the recommended design space, but cannot be optimized quantitatively to define a spectrum or light source that maximizes color preference. This is because the optimum value has not been specified and the recommended three features are not weighted.

  Solid state lighting technologies such as LEDs and LED-based devices often have superior performance compared to incandescent lamps. This performance can be quantified by lamp useful life, lamp efficiency (lumens per watt), color temperature and color fidelity and other parameters. It would be desirable to make and use an LED lighting device that also provides improved color preference characteristics.

  Commercial lamp types, including incandescent, halogen, and LED, that absorb some of the yellow light from the spectrum emitted from the light source using Nd-doped glass, compared to similar lamps that do not absorb Nd. Color preference can be improved. GE Lighting and several other manufacturers have each of these three types of products. GE Lighting products have the trade name Reveal®.

  Some special formulations of phosphors for small fluorescent lamps (CFL), straight tube fluorescent lamps (LFL) and LED lamps improve color preference compared to similar lamps using standard phosphors It is known. GE Lighting, which is also a brand name of Reveal®, has each of the first two types of products. A third type of LED light source is known for use in grocery stores, for example, to highlight the color of meat, vegetables and agricultural products (eg, fruits).

Each of these existing light sources has used either Nd-doped glass or phosphors manufactured to reduce the amount of yellow light emitted from the light source to enhance color preference. However, none of these products have achieved a level of color preference over GE Lighting's Reveal® incandescent and other existing products. These existing light source Nd filters can generally be composed of Nd ₂ O ₃ doped glass. In other embodiments, the yellow filter may be composed of various matrix host materials (e.g., glass, other elements of Nd or didymium (a mixture of elemental praseodymium and Nd) or other rare earth that preferentially absorbs yellow light. Crystal, polymer or other material), or some other dopant or glass coating that selectively absorbs the yellow range of wavelengths, or a lamp or It may be constructed by adding a yellow absorber to any optically active component of the illumination system, such as a reflector or diffuser or lens, the component comprising glass or polymer or metal containing the yellow absorber or any Other materials may be used. The exact peak wavelength and width of yellow absorption varies depending on the particular Nd or rare earth compound and matrix host material, but many combinations of Nd, didymium and other rare earth compounds and matrix host materials are available for some other A suitable substitute for a combination of Nd ₂ O ₃ doped glass as well as a yellow filter. An Nd or other yellow filter is in the shape of a dome surrounding the light source or any other geometric shape surrounding the light source so that most or all of the light in the yellow range of wavelengths passes through the filter. It's okay.

International Publication No. 2014/179000

  In one embodiment, the synthetic light source is one or more blue light sources having a peak wavelength in the range of about 400 nm to about 460 nm, one or more yellow-green garnet phosphors, and one or more narrow-band red downconverters. The lighting preference index (LPI) of the synthetic light source is 120 or more.

  In another embodiment, the synthetic light source comprises one or more blue light sources, one or more YAG: Ce phosphors, one or more narrow-band red downconverters having a peak wavelength in the range of about 400 nm to about 460 nm. The color appearance of the combined light source is expressed as follows.

式中、Ｄｕｖは合成光源の白色度の測定単位であり、Ｄｏｍ_YAGは１種以上のＹＡＧ：Ｃｅ蛍光体の主波長である。

In the formula, Duv is a unit of measurement of whiteness of the synthetic light source, and Dom _YAG is the main wavelength of one or more YAG: Ce phosphors.

  In yet another embodiment, the synthetic light source comprises one or more blue light sources having a peak wavelength in the range of about 400 nm to about 460 nm, one or more yellow-green garnet phosphors, and one or more broadband red downs. The lighting preference index (LPI) of the combined light source is 120 or more.

  In another embodiment, the synthetic light source includes one or more blue light sources having a peak wavelength in the range of about 400 nm to about 460 nm, one or more YAG: Ce phosphors, and one or more broadband red light emitting nitrides. The color appearance of the synthetic light source is expressed as follows.

式中、Ｄｕｖは合成光源の白色度の測定単位であり、Ｐｅａｋ_Nitは、１種以上の広帯域赤色窒化物蛍光体のピーク波長であり、Ｄｏｍ_YAGは１種以上のＹＡＧ：Ｃｅ蛍光体の主波長である。

Where Duv is the unit of measurement of the whiteness of the synthetic light source, Peak _Nit is the peak wavelength of one or more broadband red nitride phosphors, and Dom _YAG is the main of one or more YAG: Ce phosphors. Is the wavelength.

  In yet another embodiment, the synthetic light source is one or more blue light sources having a peak wavelength in the range of about 400 nm to about 460 nm, one or more yellow-green garnet phosphors, and one or more narrow-band reds. The combined light source has a lighting preference index (LPI) of 120 or more, including a down converter and one or more broadband red down converters.

  The features and advantages of some embodiments and the manner in which the same are accomplished are described in the following detailed description in conjunction with the accompanying drawings, which illustrate exemplary embodiments (not necessarily drawn to scale). It will become clear by doing.

FIG. 3 shows a graph of three color matching functions, XYZ tristimulus values or standard observer color response. FIG. 6 is a graph showing the product of three color matching functions and the spectrum of a standard incandescent lamp. It is a figure which shows the graph of the product of three color matching functions and the spectrum of a reveal (trademark) incandescent lamp. It is a figure which shows the chart showing the ratio (%) of the observer who selected each LED system. It is a figure which shows the graph of a "white line" (it sometimes says a "white body curve" or "white body locus | trajectory"), and the graph of a black body curve (or black body locus | trajectory or BBL). It is a figure which shows ten main categories of the hue in the a * -b * chromaticity plane defined in the Munsell classification system with respect to a color. It is a figure which shows the radial direction component and azimuth | direction angle component of a * -b * chromaticity plane containing each color rendering vector (Color Rendering Vector). It is a figure which shows the color rendering vector (CRV) of the Munsell value 5 about a neodymium incandescent lamp. It is a figure which shows an incandescent or halogen light source. It is a figure which shows the graph of the relative light output (or spectral power distribution (SPD)) with respect to the wavelength of the incandescent light source and black body light source of FIG. It is a figure which shows the plot containing the plot of SPD of an incandescent light source, and the plot of SPD of a Reveal (trademark) type | mold incandescent light source. It is a figure which shows the Reveal (trademark) type | mold LED light source containing one or more LED. FIG. 7b is an exploded view of the light source of FIG. 7a. FIG. 8 is a graph including a SPD plot of a bulb-color LED lamp including a plurality of blue LEDs each exciting a YAG phosphor and a red phosphor and a SPD plot of the Reveal® LED light source of FIG. 7a. . It is a figure which shows a Reveal (trademark) type | mold small fluorescent lamp (CFL) light source. FIG. 10 is a graph including a plot of the spectral power distribution (SPD) of the Reveal® type CFL light source of FIG. 9 and an SPD plot of the Reveal® type incandescent light source. FIG. 6 shows a SPD graph of a known light source with green and red phosphors having peak wavelengths far enough to create a depression in the yellow wavelength region. It is a figure which shows the graph of SPD of the LED light source of a prior art. It is a figure which shows the graph of SPD of blue LED of the light source which concerns on some embodiment. FIG. 6 shows SPD graphs of five different yellow-green (YG) YAG: Ce phosphors according to some embodiments. FIG. 4 shows SPD graphs of four different broadband red (BR) nitride phosphors according to some embodiments. It is a figure which shows the emission spectrum of the narrow-band red (NR) fluorescent substance which concerns on some embodiment. The color coordinates of the 1931 CIE color system of the CIE standard light D65, the chromaticity point of the YG phosphor YAG1 in FIG. 14, and the spectral trajectory of the main wavelength obtained as a result of YAG1 according to some embodiments (the circumference of the CIE color space) It is a figure which shows the upper point. It is a figure which shows the color coordinate of 1931CIE color system of the blue LED of FIG. 13, the five YG YAG phosphors of FIG. 14, and the NR phosphor of FIG. 16 according to some embodiments. (YG = yellow green; NR = narrow band red). FIG. 16 is a diagram illustrating the color coordinates of the 1931 CIE color system of the blue LED of FIG. 13, the five YG YAG phosphors of FIG. 14 and the four different broadband red nitride phosphors of FIG. 15 according to some embodiments. It is a figure which shows the color coordinate of the modified 1931CIE color system of each of five commercially available YG YAG fluorescent substance of FIG. 14, and also five YG YAG fluorescent substance. The peak wavelengths are shifted by +10 nm, +5 nm, −5 nm, and −10 nm, indicating a total of 25 SPDs representing a wide range of systematically parameterized different YG YAG phosphors according to some embodiments. FIG. 18 is a diagram showing the color coordinates of the 1931 CIE color system of the 25 systematically parameterized YG YAG: Ce phosphors of FIG. 18a and 22 commercially available YG YAG phosphors according to some embodiments. is there. It is a figure which shows the color coordinate of 1931 CIE color system of each modified type of four broadband red nitride fluorescent substance of FIG. 15, and four broadband red nitride fluorescent substance. The peak wavelengths are shifted by +10 nm, +5 nm, −5 nm, and −10 nm, showing a total of 20 SPDs representing a wide range of systematically parameterized different broadband red nitride phosphors according to some embodiments. The 1931 CIE color system of the 20 systematically parameterized broadband red nitride phosphors of FIG. 19a and 14 currently commercially available broadband red nitride phosphors according to some embodiments. It is a figure which shows a color coordinate. FIG. 18b shows the relationship between the peak wavelength and dominant wavelength of the 25 systematically parameterized YG YAG phosphors of FIG. 18a according to some embodiments. Figure 19b shows the relationship between the peak wavelength and dominant wavelength of the 20 systematically parameterized broadband red nitride phosphors of Figure 19a according to some embodiments. Illumination preference index (LPI) of the dominant wavelength of the YG YAG phosphor on the x-axis and the position of the chromaticity point of the light source in the CIE 1960u-v color space for 2700K BBL, quantified by Duv on the y-axis It is a figure which shows a contour map. The red light emitter is the NR phosphor of FIG. 16 according to some embodiments. FIG. 7 is a contour plot of LPI versus position of the chromaticity point of the light source in the CIE 1960u-v color space for 3000K BBL quantified by the dominant wavelength of the YG YAG phosphor on the x-axis and Duv on the y-axis. is there. The red light emitter is the NR phosphor of FIG. 16 according to some embodiments. FIG. 22b shows a separate implementation by the dominant wavelength of the YG YAG phosphor and represented by Duv, superimposed on the contour plot of the LPI response of FIG. 22a. The red light emitter is the NR phosphor of FIG. 16 according to some embodiments. FIG. 6 shows a separate implementation SPD having a maximum LPI value of a light source including a blue LED at 2700K, a YG YAG phosphor and an NR phosphor, according to some embodiments. FIG. 6A shows a family of analytical approximations for each of the LPI contours at 2700K in FIG. 22a, with the red illuminant being the NR phosphor of FIG. 16 superimposed on the actual LPI contours according to some embodiments. FIG. FIG. 6 shows a family of analytical approximations of each of the LPI contours at 3000K in FIG. 22b, with the red illuminant being the NR phosphor of FIG. 16 superimposed on the actual LPI contours according to some embodiments. FIG. Represents a design space that provides an LPI of 120, 125, 130, 135 or more, respectively, for contour lines of LPI = 120 (FIG. 26a), 125 (FIG. 26b), 130 (FIG. 26c), and 135 (FIG. 26d) at 2700K. FIG. 6 shows a dark shaded area defined by an analytical approximation. The red light emitter is the NR phosphor of FIG. 16 according to some embodiments. It is a figure which shows the 2700K contour map of LPI with respect to the main wavelength of YG YAG fluorescent substance on x-axis, and Duv on a y-axis. The red phosphor is the broadband red nitride phosphor of FIG. 15 having a peak wavelength of 610 nm (FIG. 27a) according to some embodiments. It is a figure which shows the 2700K contour map of LPI with respect to the main wavelength of YG YAG fluorescent substance on x-axis, and Duv on a y-axis. The red phosphor is the broadband red nitride phosphor of FIG. 15 having a peak wavelength of 620 nm (FIG. 27b) according to some embodiments. It is a figure which shows the 2700K contour map of LPI with respect to the main wavelength of YG YAG fluorescent substance on x-axis, and Duv on a y-axis. The red phosphor is the broadband red nitride phosphor of FIG. 15 having a peak wavelength of 630 nm (FIG. 27c) according to some embodiments. It is a figure which shows the 2700K contour map of LPI with respect to the main wavelength of YG YAG fluorescent substance on x-axis, and Duv on a y-axis. The red phosphor is the broadband red nitride phosphor of FIG. 15 having a peak wavelength of 640 nm (FIG. 27d) according to some embodiments. It is a figure which shows the 2700K contour map of LPI with respect to the main wavelength of YG YAG fluorescent substance on x-axis, and Duv on a y-axis. The red phosphor is the broadband red nitride phosphor of FIG. 15 having a peak wavelength of 650 nm (FIG. 27e) according to some embodiments. It is a figure which shows the 2700K contour map of LPI with respect to the main wavelength of YG YAG fluorescent substance on x-axis, and Duv on a y-axis. The red phosphor is the broadband red nitride phosphor of FIG. 15 having a peak wavelength of 660 nm (FIG. 27f) according to some embodiments. It is a figure which shows the 2700K contour map of LPI with respect to the main wavelength of YG YAG fluorescent substance on x-axis, and Duv on a y-axis. The red phosphor is the broadband red nitride phosphor of FIG. 15 having a peak wavelength of 670 nm (FIG. 27g) according to some embodiments. It is a figure which shows the 2700K contour map of LPI with respect to the main wavelength of YG YAG fluorescent substance on x-axis, and Duv on a y-axis. The red phosphor is the broadband red nitride phosphor of FIG. 15 having a peak wavelength of 680 nm (FIG. 27h) according to some embodiments. It is a figure which shows the 3000K contour map of LPI with respect to the dominant wavelength of the YG YAG fluorescent substance on x-axis, and Duv on a y-axis. The red phosphor is the broadband red nitride phosphor of FIG. 15 having a peak wavelength of 610 nm (FIG. 28a) according to some embodiments. It is a figure which shows the 3000K contour map of LPI with respect to the dominant wavelength of the YG YAG fluorescent substance on x-axis, and Duv on a y-axis. The red phosphor is the broadband red nitride phosphor of FIG. 15 having a peak wavelength of 620 nm (FIG. 28b) according to some embodiments. It is a figure which shows the 3000K contour map of LPI with respect to the dominant wavelength of the YG YAG fluorescent substance on x-axis, and Duv on a y-axis. The red phosphor is the broadband red nitride phosphor of FIG. 15 having a peak wavelength of 630 nm (FIG. 28c) according to some embodiments. It is a figure which shows the 3000K contour map of LPI with respect to the dominant wavelength of the YG YAG fluorescent substance on x-axis, and Duv on a y-axis. The red phosphor is the broadband red nitride phosphor of FIG. 15 having a peak wavelength of 640 nm (FIG. 28d) according to some embodiments. It is a figure which shows the 3000K contour map of LPI with respect to the dominant wavelength of the YG YAG fluorescent substance on x-axis, and Duv on a y-axis. The red phosphor is the broadband red nitride phosphor of FIG. 15 having a peak wavelength of 650 nm (FIG. 28e) according to some embodiments. It is a figure which shows the 3000K contour map of LPI with respect to the dominant wavelength of the YG YAG fluorescent substance on x-axis, and Duv on a y-axis. The red phosphor is the broadband red nitride phosphor of FIG. 15 having a peak wavelength of 660 nm (FIG. 28f) according to some embodiments. It is a figure which shows the 3000K contour map of LPI with respect to the dominant wavelength of the YG YAG fluorescent substance on x-axis, and Duv on a y-axis. The red phosphor is the broadband red nitride phosphor of FIG. 15 having a peak wavelength of 670 nm (FIG. 28g) according to some embodiments. It is a figure which shows the 3000K contour map of LPI with respect to the dominant wavelength of the YG YAG fluorescent substance on x-axis, and Duv on a y-axis. The red phosphor is the broadband red nitride phosphor of FIG. 15 having a peak wavelength of 680 nm (FIG. 28h) according to some embodiments. FIG. 6 shows a separate implementation SPD having a maximum LPI value of a light source including a blue LED at 2700K, a YG YAG phosphor and a broadband red nitride phosphor according to some embodiments. FIG. 28 is a diagram showing a family of analytical approximations for each of the LPI contours at 2700K in FIG. 27d superimposed on the actual LPI contours. The red phosphor is the broadband red nitride phosphor of FIG. 15 having a peak wavelength of 640 nm (FIG. 30a) according to some embodiments. FIG. 28b shows a family of analytical approximations for each of the LPI contours at 2700K of FIG. 27e superimposed on the actual LPI contours. The red phosphor is the broadband red nitride phosphor of FIG. 15 having a peak wavelength of 650 nm (FIG. 30b) according to some embodiments. FIG. 28 is a diagram showing a family of analytical approximations for each of the LPI contours at 2700K of FIG. 27f superimposed on the actual LPI contours. The red phosphor is the broadband red nitride phosphor of FIG. 15 having a peak wavelength of 660 nm (FIG. 30c) according to some embodiments. FIG. 28 shows a family of analytical approximations for each of the LPI contours at 2700 K of FIG. 27g, superimposed on the actual LPI contours. The red phosphor is the broadband red nitride phosphor of FIG. 15 having a peak wavelength of 670 nm (FIG. 30d) according to some embodiments. FIG. 28A shows a family of analytical approximations for each of the LPI contours at 2700K of FIG. 27h superimposed on the actual LPI contours. The red phosphor is the broadband red nitride phosphor of FIG. 15 having a peak wavelength of 680 nm (FIG. 30e) according to some embodiments. FIG. 29C shows a family of analytical approximations for each of the LPI contours at 3000K in FIG. 28d superimposed on the actual LPI contours. The red phosphor is the broadband red nitride phosphor of FIG. 15 having a peak wavelength of 640 nm (FIG. 31a) according to some embodiments. FIG. 28c shows a family of analytical approximations for each of the LPI contours at 3000K of FIG. 28e superimposed on the actual LPI contours. The red phosphor is the broadband red nitride phosphor of FIG. 15 having a peak wavelength of 650 nm (FIG. 31b) according to some embodiments. FIG. 29 shows a family of analytical approximations for each of the LPI contours at 3000K in FIG. 28f superimposed on the actual LPI contours. The red phosphor is the broadband red nitride phosphor of FIG. 15 having a peak wavelength of 660 nm (FIG. 31c) according to some embodiments. FIG. 29 shows a family of analytical approximations for each of the LPI contours at 3000K in FIG. 28g superimposed on the actual LPI contours. The red phosphor is the broadband red nitride phosphor of FIG. 15 having a peak wavelength of 670 nm (FIG. 31d) according to some embodiments. FIG. 29 shows a family of analytical approximations for each of the LPI contours at 3000K in FIG. 28h superimposed on the actual LPI contours. The red phosphor is the broadband red nitride phosphor of FIG. 15 having a peak wavelength of 680 nm (FIG. 31e) according to some embodiments. It is a figure which shows the 2700K contour map of LPI with respect to the main wavelength of YG YAG fluorescent substance on x-axis, and Duv on a y-axis. The red phosphor consists of 75% of the NR phosphor of FIG. 16 and 25% of the broadband red nitride phosphor of FIG. 15 having a peak wavelength of 610 nm (FIG. 32a) according to some embodiments. It is a figure which shows the 2700K contour map of LPI with respect to the main wavelength of YG YAG fluorescent substance on x-axis, and Duv on a y-axis. The red phosphor consists of 75% of the NR phosphor of FIG. 16 and 25% of the broadband red nitride phosphor of FIG. 15 having a peak wavelength of 620 nm (FIG. 32b) according to some embodiments. It is a figure which shows the 2700K contour map of LPI with respect to the main wavelength of YG YAG fluorescent substance on x-axis, and Duv on a y-axis. The red phosphor consists of 75% of the NR phosphor of FIG. 16 and 25% of the broadband red nitride phosphor of FIG. 15 having a peak wavelength of 630 nm (FIG. 32c) according to some embodiments. It is a figure which shows the 2700K contour map of LPI with respect to the main wavelength of YG YAG fluorescent substance on x-axis, and Duv on a y-axis. The red phosphor consists of 75% of the NR phosphor of FIG. 16 and 25% of the broadband red nitride phosphor of FIG. 15 having a peak wavelength of 640 nm (FIG. 32d) according to some embodiments. It is a figure which shows the 2700K contour map of LPI with respect to the main wavelength of YG YAG fluorescent substance on x-axis, and Duv on a y-axis. The red phosphor consists of 75% of the NR phosphor of FIG. 16 and 25% of the broadband red nitride phosphor of FIG. 15 having a peak wavelength of 650 nm (FIG. 32e) according to some embodiments. It is a figure which shows the 2700K contour map of LPI with respect to the main wavelength of YG YAG fluorescent substance on x-axis, and Duv on a y-axis. The red phosphor consists of 75% of the NR phosphor of FIG. 16 and 25% of the broadband red nitride phosphor of FIG. 15 having a peak wavelength of 660 nm (FIG. 32f) according to some embodiments. It is a figure which shows the 2700K contour map of LPI with respect to the main wavelength of YG YAG fluorescent substance on x-axis, and Duv on a y-axis. The red phosphor consists of 75% of the NR phosphor of FIG. 16 and 25% of the broadband red nitride phosphor of FIG. 15 having a peak wavelength of 670 nm (FIG. 32g) according to some embodiments. It is a figure which shows the 2700K contour map of LPI with respect to the main wavelength of YG YAG fluorescent substance on x-axis, and Duv on a y-axis. The red phosphor consists of 75% of the NR phosphor of FIG. 16 and 25% of the broadband red nitride phosphor of FIG. 15 having a peak wavelength of 680 nm (FIG. 32h) according to some embodiments. It is a figure which shows the 3000K contour map of LPI with respect to the dominant wavelength of the YG YAG fluorescent substance on x-axis, and Duv on a y-axis. The red phosphor consists of 75% of the NR phosphor of FIG. 16 and 25% of the broadband red nitride phosphor of FIG. 15 having a peak wavelength of 610 nm (FIG. 33a) according to some embodiments. It is a figure which shows the 3000K contour map of LPI with respect to the dominant wavelength of the YG YAG fluorescent substance on x-axis, and Duv on a y-axis. The red phosphor consists of 75% of the NR phosphor of FIG. 16 and 25% of the broadband red nitride phosphor of FIG. 15 having a peak wavelength of 620 nm (FIG. 33b) according to some embodiments. It is a figure which shows the 3000K contour map of LPI with respect to the dominant wavelength of the YG YAG fluorescent substance on x-axis, and Duv on a y-axis. The red phosphor consists of 75% of the NR phosphor of FIG. 16 and 25% of the broadband red nitride phosphor of FIG. 15 having a peak wavelength of 630 nm (FIG. 33c) according to some embodiments. It is a figure which shows the 3000K contour map of LPI with respect to the dominant wavelength of the YG YAG fluorescent substance on x-axis, and Duv on a y-axis. The red phosphor consists of 75% of the NR phosphor of FIG. 16 and 25% of the broadband red nitride phosphor of FIG. 15 having a peak wavelength of 640 nm (FIG. 33d) according to some embodiments. It is a figure which shows the 3000K contour map of LPI with respect to the dominant wavelength of the YG YAG fluorescent substance on x-axis, and Duv on a y-axis. The red phosphor consists of 75% of the NR phosphor of FIG. 16 and 25% of the broadband red nitride phosphor of FIG. 15 having a peak wavelength of 650 nm (FIG. 33e) according to some embodiments. It is a figure which shows the 3000K contour map of LPI with respect to the dominant wavelength of the YG YAG fluorescent substance on x-axis, and Duv on a y-axis. The red phosphor consists of 75% of the NR phosphor of FIG. 16 and 25% of the broadband red nitride phosphor of FIG. 15 having a peak wavelength of 660 nm (FIG. 33f) according to some embodiments. It is a figure which shows the 3000K contour map of LPI with respect to the dominant wavelength of the YG YAG fluorescent substance on x-axis, and Duv on a y-axis. The red phosphor consists of 75% of the NR phosphor of FIG. 16 and 25% of the broadband red nitride phosphor of FIG. 15 having a peak wavelength of 670 nm (FIG. 33g) according to some embodiments. It is a figure which shows the 3000K contour map of LPI with respect to the dominant wavelength of the YG YAG fluorescent substance on x-axis, and Duv on a y-axis. The red phosphor consists of 75% of the NR phosphor of FIG. 16 and 25% of the broadband red nitride phosphor of FIG. 15 having a peak wavelength of 680 nm (FIG. 33h) according to some embodiments. The maximum LPI value of a light source comprising a blue LED at 2700K, a red light emitter comprised of 75% NR phosphor and 25% broadband red nitride phosphor according to some embodiments FIG. 6 is a diagram illustrating a separate implementation of SPD. It is a figure which shows the 2700K contour map of LPI with respect to the main wavelength of YG YAG fluorescent substance on x-axis, and Duv on a y-axis. The red phosphor consists of 50% of the NR phosphor of FIG. 16 and 50% of the broadband red nitride phosphor of FIG. 15 having a peak wavelength of 610 nm (FIG. 35a) according to some embodiments. It is a figure which shows the 2700K contour map of LPI with respect to the main wavelength of YG YAG fluorescent substance on x-axis, and Duv on a y-axis. The red phosphor consists of 50% of the NR phosphor of FIG. 16 and 50% of the broadband red nitride phosphor of FIG. 15 having a peak wavelength of 620 nm (FIG. 35b) according to some embodiments. It is a figure which shows the 2700K contour map of LPI with respect to the main wavelength of YG YAG fluorescent substance on x-axis, and Duv on a y-axis. The red phosphor consists of 50% of the NR phosphor of FIG. 16 and 50% of the broadband red nitride phosphor of FIG. 15 with a peak wavelength of 630 nm (FIG. 35c) according to some embodiments. It is a figure which shows the 2700K contour map of LPI with respect to the main wavelength of YG YAG fluorescent substance on x-axis, and Duv on a y-axis. The red phosphor consists of 50% of the NR phosphor of FIG. 16 and 50% of the broadband red nitride phosphor of FIG. 15 with a peak wavelength of 640 nm (FIG. 35d) according to some embodiments. It is a figure which shows the 2700K contour map of LPI with respect to the main wavelength of YG YAG fluorescent substance on x-axis, and Duv on a y-axis. The red phosphor consists of 50% of the NR phosphor of FIG. 16 and 50% of the broadband red nitride phosphor of FIG. 15 having a peak wavelength of 650 nm (FIG. 35e) according to some embodiments. It is a figure which shows the 2700K contour map of LPI with respect to the main wavelength of YG YAG fluorescent substance on x-axis, and Duv on a y-axis. The red phosphor consists of 50% of the NR phosphor of FIG. 16 and 50% of the broadband red nitride phosphor of FIG. 15 having a peak wavelength of 660 nm (FIG. 35f) according to some embodiments. It is a figure which shows the 2700K contour map of LPI with respect to the main wavelength of YG YAG fluorescent substance on x-axis, and Duv on a y-axis. The red phosphor consists of 50% of the NR phosphor of FIG. 16 and 50% of the broadband red nitride phosphor of FIG. 15 having a peak wavelength of 670 nm (FIG. 35g) according to some embodiments. It is a figure which shows the 2700K contour map of LPI with respect to the main wavelength of YG YAG fluorescent substance on x-axis, and Duv on a y-axis. The red phosphor consists of 50% of the NR phosphor of FIG. 16 and 50% of the broadband red nitride phosphor of FIG. 15 having a peak wavelength of 680 nm (FIG. 35h) according to some embodiments. It is a figure which shows the 3000K contour map of LPI with respect to the dominant wavelength of the YG YAG fluorescent substance on x-axis, and Duv on a y-axis. The red phosphor consists of 50% of the NR phosphor of FIG. 16 and 50% of the broadband red nitride phosphor of FIG. 15 having a peak wavelength of 610 nm (FIG. 36a) according to some embodiments. It is a figure which shows the 3000K contour map of LPI with respect to the dominant wavelength of the YG YAG fluorescent substance on x-axis, and Duv on a y-axis. The red phosphor consists of 50% of the NR phosphor of FIG. 16 and 50% of the broadband red nitride phosphor of FIG. 15 with a peak wavelength of 620 nm (FIG. 36b) according to some embodiments. It is a figure which shows the 3000K contour map of LPI with respect to the dominant wavelength of the YG YAG fluorescent substance on x-axis, and Duv on a y-axis. The red phosphor consists of 50% of the NR phosphor of FIG. 16 and 50% of the broadband red nitride phosphor of FIG. 15 having a peak wavelength of 630 nm (FIG. 36c) according to some embodiments. It is a figure which shows the 2700K contour map of LPI with respect to the main wavelength of YG YAG fluorescent substance on x-axis, and Duv on a y-axis. The red phosphor consists of 50% of the NR phosphor of FIG. 16 and 50% of the broadband red nitride phosphor of FIG. 15 having a peak wavelength of 640 nm (FIG. 36d) according to some embodiments. It is a figure which shows the 2700K contour map of LPI with respect to the main wavelength of YG YAG fluorescent substance on x-axis, and Duv on a y-axis. The red phosphor consists of 50% of the NR phosphor of FIG. 16 and 50% of the broadband red nitride phosphor of FIG. 15 having a peak wavelength of 650 nm (FIG. 36e) according to some embodiments. It is a figure which shows the 2700K contour map of LPI with respect to the main wavelength of YG YAG fluorescent substance on x-axis, and Duv on a y-axis. The red phosphor consists of 50% of the NR phosphor of FIG. 16 and 50% of the broadband red nitride phosphor of FIG. 15 with a peak wavelength of 660 nm (FIG. 36f) according to some embodiments. It is a figure which shows the 2700K contour map of LPI with respect to the main wavelength of YG YAG fluorescent substance on x-axis, and Duv on a y-axis. The red phosphor consists of 50% of the NR phosphor of FIG. 16 and 50% of the broadband red nitride phosphor of FIG. 15 with a peak wavelength of 670 nm (FIG. 36g) according to some embodiments. It is a figure which shows the 2700K contour map of LPI with respect to the main wavelength of YG YAG fluorescent substance on x-axis, and Duv on a y-axis. The red phosphor consists of 50% of the NR phosphor of FIG. 16 and 50% of the broadband red nitride phosphor of FIG. 15 having a peak wavelength of 680 nm (FIG. 36h) according to some embodiments. The maximum LPI value of a light source comprising a blue LED at 2700K, a red light emitter comprising 50% NR phosphor and 50% broadband red nitride phosphor according to some embodiments FIG. 6 is a diagram illustrating a separate implementation of SPD. It is a figure which shows the contour-line figure in 2700K of LPI with respect to the dominant wavelength of YG YAG fluorescent substance on x-axis, and Duv on a y-axis. The red phosphor consists of 25% of the NR phosphor of FIG. 16 and 75% of the broadband red nitride phosphor of FIG. 15 having a peak wavelength of 610 nm (FIG. 38a) according to some embodiments. It is a figure which shows the contour-line figure in 2700K of LPI with respect to the dominant wavelength of YG YAG fluorescent substance on x-axis, and Duv on a y-axis. The red phosphor consists of 25% of the NR phosphor of FIG. 16 and 75% of the broadband red nitride phosphor of FIG. 15 having a peak wavelength of 620 nm (FIG. 38b) according to some embodiments. It is a figure which shows the contour-line figure in 2700K of LPI with respect to the dominant wavelength of YG YAG fluorescent substance on x-axis, and Duv on a y-axis. The red phosphor consists of 25% of the NR phosphor of FIG. 16 and 75% of the broadband red nitride phosphor of FIG. 15 having a peak wavelength of 630 nm (FIG. 38c) according to some embodiments. It is a figure which shows the contour-line figure in 2700K of LPI with respect to the dominant wavelength of YG YAG fluorescent substance on x-axis, and Duv on a y-axis. The red phosphor consists of 25% of the NR phosphor of FIG. 16 and 75% of the broadband red nitride phosphor of FIG. 15 with a peak wavelength of 640 nm (FIG. 38d) according to some embodiments. It is a figure which shows the contour-line figure in 2700K of LPI with respect to the dominant wavelength of YG YAG fluorescent substance on x-axis, and Duv on a y-axis. The red phosphor consists of 25% of the NR phosphor of FIG. 16 and 75% of the broadband red nitride phosphor of FIG. 15 having a peak wavelength of 650 nm (FIG. 38e) according to some embodiments. It is a figure which shows the contour-line figure in 2700K of LPI with respect to the dominant wavelength of YG YAG fluorescent substance on x-axis, and Duv on a y-axis. The red phosphor consists of 25% of the NR phosphor of FIG. 16 and 75% of the broadband red nitride phosphor of FIG. 15 having a peak wavelength of 660 nm (FIG. 38f) according to some embodiments. It is a figure which shows the contour-line figure in 2700K of LPI with respect to the dominant wavelength of YG YAG fluorescent substance on x-axis, and Duv on a y-axis. The red phosphor consists of 25% of the NR phosphor of FIG. 16 and 75% of the broadband red nitride phosphor of FIG. 15 having a peak wavelength of 670 nm (FIG. 38g) according to some embodiments. It is a figure which shows the contour-line figure in 2700K of LPI with respect to the dominant wavelength of YG YAG fluorescent substance on x-axis, and Duv on a y-axis. The red phosphor consists of 25% of the NR phosphor of FIG. 16 and 75% of the broadband red nitride phosphor of FIG. 15 with a peak wavelength of 680 nm (FIG. 38h) according to some embodiments. It is a figure which shows the contour map in 3000K of LPI with respect to the dominant wavelength of YG YAG fluorescent substance on an x-axis, and Duv on a y-axis. The red phosphor consists of 25% of the NR phosphor of FIG. 16 and 75% of the broadband red nitride phosphor of FIG. 15 having a peak wavelength of 610 nm (FIG. 39a) according to some embodiments. It is a figure which shows the contour map in 3000K of LPI with respect to the dominant wavelength of YG YAG fluorescent substance on an x-axis, and Duv on a y-axis. The red phosphor consists of 25% of the NR phosphor of FIG. 16 and 75% of the broadband red nitride phosphor of FIG. 15 having a peak wavelength of 620 nm (FIG. 39b) according to some embodiments. It is a figure which shows the contour map in 3000K of LPI with respect to the dominant wavelength of YG YAG fluorescent substance on an x-axis, and Duv on a y-axis. The red phosphor consists of 25% of the NR phosphor of FIG. 16 and 75% of the broadband red nitride phosphor of FIG. 15 having a peak wavelength of 630 nm (FIG. 39c) according to some embodiments. FIG. 6 is a diagram showing a contour map of K at 3000 of LPI with respect to the dominant wavelength of the YG YAG phosphor on the x-axis and Duv on the y-axis. The red phosphor consists of 25% of the NR phosphor of FIG. 16 and 75% of the broadband red nitride phosphor of FIG. 15 having a peak wavelength of 640 nm (FIG. 39d) according to some embodiments. It is a figure which shows the contour map in 3000K of LPI with respect to the dominant wavelength of YG YAG fluorescent substance on an x-axis, and Duv on a y-axis. The red phosphor consists of 25% of the NR phosphor of FIG. 16 and 75% of the broadband red nitride phosphor of FIG. 15 having a peak wavelength of 650 nm (FIG. 39e) according to some embodiments. It is a figure which shows the contour map in 3000K of LPI with respect to the dominant wavelength of YG YAG fluorescent substance on an x-axis, and Duv on a y-axis. The red phosphor consists of 25% of the NR phosphor of FIG. 16 and 75% of the broadband red nitride phosphor of FIG. 15 having a peak wavelength of 660 nm (FIG. 39f) according to some embodiments. It is a figure which shows the contour map in 3000K of LPI with respect to the dominant wavelength of YG YAG fluorescent substance on an x-axis, and Duv on a y-axis. The red phosphor consists of 25% of the NR phosphor of FIG. 16 and 75% of the broadband red nitride phosphor of FIG. 15 having a peak wavelength of 670 nm (FIG. 39g) according to some embodiments. It is a figure which shows the contour map in 3000K of LPI with respect to the dominant wavelength of YG YAG fluorescent substance on an x-axis, and Duv on a y-axis. The red phosphor consists of 25% of the NR phosphor of FIG. 16 and 75% of the broadband red nitride phosphor of FIG. 15 having a peak wavelength of 680 nm (FIG. 39h) according to some embodiments. A light source comprising a blue LED at 2700K according to some embodiments, a YG YAG phosphor, and a red emitter composed of 25% NR (narrowband red) phosphor and 75% broadband red nitride phosphor FIG. 6 shows separate implementation SPDs with maximum LPI values of. FIG. 4 shows the maximum LPI achievable at 2700 K as a function of BR (broadband red) nitride peak wavelength for different compositions of red emitters according to some embodiments.

  As used herein, the term “light source” covers any source of visible light, such as a semiconductor or LED or OLED, or a downconverter such as a phosphor or quantum dot, or a remote downconverter or reflector or refractive medium. Or a downconverter embedded in a reflector or refractive medium, or a multi-channel combination or composite light source consisting of several such light sources, or a system such as a lamp or luminaire or equipment comprising such light sources May mean

  A new quantitative validated color preference metric called the Lighting Preference Index (LPI) is presented here. LPI can be used to obtain design rules for maximizing the color preference characteristics of a light source and / or for multiple responses of a spectrum including color preference along with other photometric, colorimetric and other design responses. It can be used as a quantitative metric for designing optimization. The resulting spectrum, light source and lamp exhibit unexpectedly high LPI values, which represent a much higher color preference than existing Reveal® type light sources and / or similar conventional products.

  Since the improvement in color preference is due to a combination of improved color contrast and whiteness, the LPI color metric is a quantitative optimization of color preference by adjusting the spectral power distribution of the light source. May be possible.

In one or more embodiments, the individual light sources may be commercially available or simply manufactured blue LEDs, yellow-green garnet phosphors, broadband red nitride phosphors and narrow-band red phosphors. However, it may be combined in a novel manner as described in this disclosure. This is in contrast to the light sources described in US patent application 61/875403 and PCT international application PCT / US2014 / 054868, incorporated herein by reference. The light source is described as a combination of green and red light sources in addition to the current blue LED, each represented by a Gaussian distribution of wavelengths characterized by peak wavelength and full width at half maximum (FWHM). In the patent applications of US patent application 61/875403 and PCT international application PCT / US2014 / 054868, the Gaussian distribution is a hypothetical approximation of actual phosphors and LEDs. Therefore, although the SPDs in these prior applications are not necessarily equal to the actual LED and phosphor SPDs, embodiments of the present invention provide actual yellow-green and red phosphor SPDs. In one or more embodiments of the present disclosure, the synthetic light source is a commercially available blue or violet LED, a yellow-green garnet phosphor, either a broadband red nitride phosphor or a narrow band red phosphor, or a broadband red fluorescence. Body and a combination of narrow-band red phosphors. Other suitable light sources may be used. The blue LED may include a nitride compound semiconductor represented by the following formula. In _i Ga _j Al _k N (where i ≧ 0, j ≧ 0, k ≧ 0 and i + j + k = 1). In one or more embodiments, well-known InGaN blue or violet LEDs are used, where k = 0, i is in the range of about 0.1 to about 0.4, and the peak emission wavelength is about 10 nm. A range of about 400 nm to about 460 nm with a FWHM of about 20 nm. The yellow-green (YG) phosphor is selected from 1) one or more elements selected from the group consisting of Y, Lu, Sc, La, Gd, Tb and Sm and 2) a group consisting of Al, Ga and In. And a garnet fluorescent material activated with Ce may be included. In one or more embodiments, the garnet phosphor may be further limited to Ce-doped yttrium aluminum garnet (YAG, Y ₃ Al ₅ O ₁₂ ), ie, YAG: Ce ³⁺ . A red phosphor can be defined for the purposes of the present invention as having two ranges of FWHM: a narrow FWHM of less than about 60 nm and a broad FWHM of greater than about 60 nm. In general, BR nitride phosphor material absorbs UV and blue light strongly, can emit light efficiently between about 600 nm and 670 nm, and FWHM is about 80 nm to about 120 nm so Instead, the luminous efficiency (lumen per watt, LPW) is relatively low. An example of a broadband red (BR) nitride phosphor is generally represented by the general formula CaAlSiN ₃ : Eu ²⁺ . In general, narrow-band red (NR) phosphors absorb blue light strongly, can emit light efficiently between about 610 nm and 660 nm, and emit little deep red or near-infrared emission. Some examples of known NR phosphors include those based on composite fluoride materials activated by Mn ⁴⁺ , such as those described in US Pat. No. 7,358,542, US Pat. No. 7,497,973 and US Pat. No. 7,648,649. Etc. The Mn ⁴⁺ doped phosphor has the formula A _x [MF _y ]: Mn ⁴⁺ . In the formula, A (alkali) is Li, Na, K, Rb, Cs or a combination thereof, and M (metal) is Si, Ge, Sn, Ti, Zr, AI, Ga, In, Sc, Hf. , Y, La, Nb, Ta, Bi, Gd or combinations thereof, x is the absolute value of the charge of [MF _y ] ion, and y is 5, 6 or 7. Therefore, LPW may be maximized compared to a red phosphor that emits light with a deep red color with poor visibility. Color saturation may also generally be enhanced, especially when the peak of the NR phosphor is below about 620 nm. In one or more embodiments, the NR phosphor can produce a strong red emission line of about 631 nm with an FWHM of less than about 10 nm when excited by an InGaN blue emitter from about 400 nm to about 460 nm [K ₂ [ SiF ₆ ]: Mn ⁴⁺ (manganese doped potassium fluoro-silicate, referred to as “PFS”).

  The LPI disclosed herein describes both the preferred color appearance (saturation and hue distortion) and the preferred shift of the chromaticity point away from the full radiator (blackbody) trajectory. LPI is a predictive metric that quantifies consumer preferences. Thus, LPI can be used as a design tool for optimizing the spectrum for color preference. In particular, a strong correlation with LPI is found in preliminary observer tests, and LPI's ability to optimize as a highly accurate predictive preference metric is demonstrated by additional tests. In an observer survey with 86 participants, four individual LED systems were designed for different and improved LPI levels ranging from 114-143. All observers in this study ranged in age from 17 to 28 years, the gender distribution was 40% male and 60% female, the race distribution was 57% white, 30% Asian, 8% Hispanic and African American 5%, geographical distribution was North America 94%, Asia 5% and Europe 1%. Each LED system illuminated a separate booth containing household items such as colorful fabrics, fruits, wood flooring and mirrors. The observer was asked to choose a generally favorable lighting environment. The result shows that the LED system with the highest LPI value was most preferred by the observer, while the second, third, and fourth highest LPI values were preferred by the second, third, and fourth, respectively. Show. FIG. 2 shows the percentage of viewers who selected each LED system as the preferred environment. As shown, the highest percentage of observers (42%) preferred light source D with an LPI of 143, while the lowest percentage of observers (11%) preferred light source A with an LPI of 114.

  Traditional or existing color and light measurement quantities or metrics are derived from the response of a relatively small observer population, so any demographic population and Nor does it represent a cultural group. However, such metrics have been used for decades since it was devised to design, evaluate and optimize lighting products. Light sources are still designed based on these metrics, for example lumens and color rendering index (CRI or Ra).

  The LPI formula described herein has an age range of 21-27 years, a gender distribution of 58% male and 42% female, a racial distribution of 92% white and 8% Asian, Based on a set of observers whose geographic distribution is within North America. However, this does not diminish the effectiveness of the LPI currently defined herein, which quantifies and optimizes the level of color preference for a given light source spectrum. When a group with a color preference similar to that of a particular test population is observed, the test light source is preferred compared to other light sources that the test population has a low rating on the LPI scale. In addition, a spectrum or light source that is optimized for high LPI and has a higher LPI than conventional light sources can be compared with conventional viewers (which tend to have a color preference similar to our dataset). The color preference of a color higher than any light source is shown. As inferences, a variant of the lumen different from the conventional photopic lumen, for example, a scotopic lumen is defined, and the definition of the scotopic lumen improves the light emission efficiency or optimizes the scotopic luminous Even if development is possible, it does not invalidate the effectiveness of the discovery and development of light sources that have been and will continue to provide improved or optimized photopic lumens. This is because the lumen is strictly defined even if it is not universally appropriate for all lighting applications.

  Whereas existing color metrics strive to accurately quantify consumer preferences for lighting products, LPI correlates most closely with a limited population of observers from whom color preference data was available. Objectively define a quantitative color preference metric. The LPI metric is a function of two parameters: the whiteness of the illumination source and the color appearance of the object illuminated by the illumination source. Specific LPI functions are defined below after the description of whiteness and color appearance.

  In this specification, whiteness refers to the proximity of a chromaticity point to a “white line” on a chromaticity diagram, and the “white line” is defined in the following publication. “White Lighting”, Color Research & Application, volume 38, # 2, pp. 82-92 (2013), authors M.M. S. Rea & J. P. Freyssinier (hereinafter referred to as “Rea References”). The Rea reference is hereby incorporated by reference. As used herein, a “white line” is defined by the chromaticity point in Table 1 below, reported in CCX and CCY color coordinates for a selected color temperature from 2700K to 6500K.

図３に示し、表１で定義したように、「白色ライン」３０４（時には「白体ライン」、「白体曲線」又は「白体軌跡」とも呼ばれる）は、高い色温度（例えば、４０００Ｋ超）で黒体曲線３０２よりもわずかに高く、低い色温度ではそれよりもはるかに下回る。研究により、「白色ライン」上の照明は、ヒト知覚の「白い」光に相当する可能性があることが示されている。「白色ライン」は広範囲の色温度に提案されるが、約２７００Ｋ〜約３０００Ｋの間の色温度（これらは、消費者が好むことの多い相関色温度（ＣＣＴ）値である）に関して、「白色ライン」は、黒体軌跡よりも約０．０１０Ｄｕｖ低く、このＤｕｖは、ｕ−ｖ色度空間での黒体軌跡からの距離を表す。

As shown in FIG. 3 and defined in Table 1, “white line” 304 (sometimes also referred to as “white body line”, “white body curve” or “white body locus”) has a high color temperature (eg, over 4000K). ) Slightly higher than the blackbody curve 302 and much lower at lower color temperatures. Studies have shown that illumination on the “white line” may correspond to human-perceived “white” light. “White lines” are proposed for a wide range of color temperatures, but for color temperatures between about 2700K to about 3000K (these are correlated color temperature (CCT) values that consumers often prefer), The “line” is about 0.010 Duv lower than the black body locus, and this Duv represents the distance from the black body locus in the uv chromaticity space.

  The following equation is set to provide a whiteness metric for any chromaticity point having a CCT between about 2700K and about 3000K. This whiteness metric is zero or substantially 0 for any point on the complete radiator trajectory and 1 (substantially 1) for any point on the “white line”.

式中、Ｄｕｖは、式（１）については、ｕ−ｖ空間での完全放射体軌跡からの色度点の距離である（注：黒体ラインよりも低い値は式（１）において負である）。例えば、黒体よりも低い０．０１０の点には、−０．０１０を式（１）に挿入することになる。（約２７００Ｋ〜約３０００Ｋの範囲外のＣＣＴを有する色度点には、白色度は、不要な実験をすることなく図３中の色度点の位置を詳しく調べることによって近似させることができる、例えば、照明源が「白色ライン」上の色度点を有する場合、それは同様に１の白色度値を有することになる）。下でさらに詳細に説明されるように、ＬＰＩは照明源の色度点が「白色ライン」に近づくにつれて増加し、それがいずれかの方向に離れるにつれて低下する。

Where Duv is the distance of the chromaticity point from the complete radiator trajectory in uv space for equation (1) (Note: values lower than the blackbody line are negative in equation (1)) is there). For example, -0.010 is inserted into the equation (1) at a point 0.010 lower than the black body. (For chromaticity points with a CCT outside the range of about 2700K to about 3000K, whiteness can be approximated by examining the location of the chromaticity points in FIG. 3 without undue experimentation. For example, if the illumination source has a chromaticity point on the “white line”, it will likewise have a whiteness value of 1). As explained in more detail below, the LPI increases as the chromaticity point of the illumination source approaches the “white line” and decreases as it moves away in either direction.

  As used herein, color appearance is a complex unit of measurement of color rendering, which is a net saturation value (NSV) of an illumination source (eg, showing increased saturation but not oversaturated). NSV gives a relatively high LPI value) and Hue Distortion Value (HDV) (for example, HDV showing minimum or zero hue distortion gives a relatively high LPI value) It is. Both NSV and HDV are described in more detail below.

The Lighting Preference Index (LPI) metric was developed using an unbiased selection of test color samples by selecting a color array using a complete database of 1600 corrected Munsell gloss spectral reflectances. These 1600 colors are in particular M.I. W. Derhak & R. S. Those skilled in the art will understand Bernns, “Analysis and Correction of the Joensuu Munsell Glossy Spectral Database”, Color and Imaging Conference , 2012 (1), 191-194 (2012). By using this color arrangement, a significant portion of the color space can be covered using the Munsell classification system consisting of hue, value and saturation.

  Also, as will be appreciated by those skilled in the art, each color in this array has a hue (10 categories with 4 subcategories in each, for a total of 40 items), saturation (0-16 Range) and values (range 0-10) are defined by the Munsell system. Ten categories of hues are depicted and classified in FIG. 4a. All levels of saturation or saturation and hue are equally weighted, “Statistical Approach to Color of Solid-state Lamps”, IEEE J. MoI. Sel. Top. Quantum Electron. 15 (6), 1753 (2009), authors A. et al. Zukauskas, R.A. Vaicekauskas, F.M. Ivanauskas, H.M. Vaitevivicius, P.M. Vitta, and M.M. S. It is processed with a statistical counting approach according to a similar method as discussed in Shur.

The chromaticity points of all 1600 color samples displayed at the same color temperature by the illumination source (ie, test illuminant) and CIE reference light, ie, full emitter, are calculated. The CIE reference light has a spectrum determined from the CCT of the illumination source using Planck's law of black body radiation. Planck's law is defined as follows, where the radiance (W / sr · m ³ ) of the light source B is a function of the wavelength λ (meter) and the absolute temperature T (K).

式中、ｈはプランク定数であり、ｋ_Bはボルツマン定数である。本明細書において、また当技術分野で公知のように、黒体は、理想的な吸収材である物体である、つまり、黒体は周波数又は入射角にかかわらず全ての入射電磁線を吸収する。また、それは理想的な発光体でもある、つまり、あらゆる周波数で、黒体は同じ温度の任意の他の物体と同程度−又はそれよりも多くの−エネルギーを発する。

In the formula, h is a Planck constant and k _B is a Boltzmann constant. As used herein and as known in the art, a black body is an object that is an ideal absorber, that is, the black body absorbs all incident electromagnetic radiation regardless of frequency or angle of incidence. . It is also an ideal light emitter, i.e., at any frequency, a black body emits as much energy as any other object at the same temperature-or more.

Next, all of these chromaticity points (also referred to as color coordinates) are converted into a CIE L * a * b * (CIELAB) color space to generate a color rendering vector (CRV). CRV represents the magnitude and direction of the color appearance shift with respect to the reference light. FIG. 4b shows the components included in each CRV. A radial component 401 or ΔC _ab quantifies a shift in saturation or saturation, where a shift away from the origin means an increase in saturation and a shift closer to the origin means a decrease in saturation. Orientation component 403 or Delta] h _ab is to quantify the change in hue, it can be represented by an angle of change (radian). A CRV vector plot of a specific Munsell value can be generated as a visual representation of the color shift on the a * -b * chromaticity plane. FIG. 4 c represents a CRV 402 with a Munsell value of 5 for a neodymium incandescent lamp, a product generally preferred by consumers. As can be seen from the vector plot, neodymium lamps produce increased saturation, especially for the red and green components (on the right and left sides of the vector plot, respectively). The approximate vector directions corresponding to yellow Y, red R, purple P, blue B and green G are shown in inset 404.

  Next, the radial 401 and azimuth 403 components of each CRV for all 1600 Munsell colors are determined to quantify the saturation and hue shifts, respectively. For such large sample sizes, the CRV magnitude and direction can be expressed in statistical counts.

Net Saturation Value (NSV) represents the percentage of the test sample with increased saturation minus the percentage of the sample with decreased saturation. The improvement in saturation level is indicated by an increase in saturation (ΔC _ab > 0) that exceeds the average perceptual difference threshold but is below the supersaturation limit. A decrease in saturation level (ΔC _ab <0) is counted only when the saturation decreases beyond the same average perceptual difference threshold. The average perceived difference value is the following publication that found that the perceivable average radius is 2.3 in CIELAB space: “Evaluation of Uniform Color Space Developed After the Citilab and CielAB and CELUV”. 19, # 2, pp. 105-121 (1994), authors M.M. Mahy, L .; Van Eicken, & A. Based on Oosterlink. For the supersaturation limit, a value of ΔC _ab = 15 is selected based on the following publications. “Color Quality Design for Solid State Lighting”, Presentation at LEDs 2012, Oct. 11-12, San Diego, CA (2012), author Y. Ohno. In this study, an increase in preference for saturated colors was found up to a certain limit, and a high level of saturation reduced the preference response. Around the value of about ΔC _ab = 15, the preference response was comparable with no saturation, ie ΔC _ab = 0, and the preference response increased between these two values.

Individual NSV values (NSV _i ) are calculated for the 10 main hue categories of the Munsell system and the total NSV is the average of the 10 hues. In this disclosure, NSV is defined by Equation (2) and Equation (3).

式中、ΔＣ_abはＣＲＶの半径方向成分であり、知覚された彩度又は飽和度のシフトを表し、ｉはマンセル系の１０の主な色相カテゴリの色相カテゴリを表す。領域−２．３＜ΔＣ_ab＜２．３に関して、飽和度の変化は、典型的な観察者に知覚されない可能性があるので、向上とも低下ともカウントされない。

Where ΔC _ab is the radial component of CRV and represents the perceived saturation or saturation shift, and i represents the hue category of the 10 main hue categories of the Munsell system. For the region -2.3 <ΔC _ab <2.3, the change in saturation may not be perceived by a typical observer and therefore is not counted as an improvement or a decrease.

  Hue Distortion Value (HDV) represents a weighted percentage of the test sample where the hue changes. While an increase in saturation (to the limit) generally does not contribute to achieving a relatively high LPI value, a change in hue is generally undesirable (but a change in hue leads to a final LPI value that is relatively weaker than a change in saturation). Is a contributing factor.

As will be appreciated by those skilled in the art, the Munsell color system is generally divided into 40 hue subcategories (there are 4 subcategories in each of the 10 main hue categories). To calculate HDV, the percentage of test colors that change to the adjacent hue subcategory (where Δh _ab > π / 20 radians (or 1/40 of a circle)) is calculated by dividing the separation angle between hue sub-levels (π / was adjusted by 20 radians), attached weighted by the average Delta] h _ab value. This additional weighting is used to account for a very large amount of hue distortion. Here, since almost all test colors experience hue distortion above the threshold at which they are counted, only the percentage approaches the limit at a very high percentage. For these calculations, the direction of hue distortion is not important, so Δh _ab > 0 for both clockwise and counterclockwise distortion. For NSV, individual HDV values (HDV _i ) are calculated for the 10 main hue categories of Munsell and the total HDV is the average of the 10 hues. In this disclosure, HDV is defined by equations (4) and (5).

式中、Δｈ_abは、ＣＲＶの方位成分であり、知覚された色相のシフトを表し、ｉは、マンセル系の１０の主な色相カテゴリの色相カテゴリを表し、Δｈ_ab,avg,iは、色相ｉ内の全ての色の平均Δｈ_ab値である。

Where Δh _ab is the azimuth component of CRV and represents the perceived hue shift, i represents the hue category of the 10 main Munsell hue categories, and Δh _{ab, avg, i} represents the hue The average Δh _ab value of all colors in i.

  Next, NSV and HDV are integrated into the color appearance value according to equation (6).

式（６）において、観察者の嗜好応答に最も適合するように、ＨＤＶは、ＮＳＶに対して重み付けられる（すなわち係数で除算される）ことに注意されたい。現実的に、通常達成されるカラーアピアランスの最大値は約１であるが、理論的にはそれはＮＳＶ＝１００及びＨＤＶ＝０で２の値に到達することが可能である。

Note that in Equation (6), HDV is weighted (ie, divided by a factor) to NSV to best fit the observer's preference response. In practice, the maximum color appearance normally achieved is about 1, but theoretically it can reach a value of 2 with NSV = 100 and HDV = 0.

  Finally, the LPI equation is defined by Equation 7.

式中、白色度は式（１）で定義され、カラーアピアランスは式（６）で定義される。「１００」のパラメータは、その他の照明測定基準と同様に基準黒体発光体が１００のベースライン値を得るように選択される。「５０」のパラメータは、ＬＰＩ変化をＣＲＩと同様の大きさに調整するために選択される。例えば、典型的なネオジム白熱灯は、ＣＲＩ系で約２０ポイント減点され、基準のＣＲＩ＝１００に対してＣＲＩは約８０となりうるが、一方、ＬＰＩ系では同じネオジム白熱灯に約２０ポイントが与えられ、基準のＬＰＩ＝１００に対してＬＰＩは約１２０となりうる。３８％の白色度及び６２％のカラーアピアランスの重み付け係数は、観察者の嗜好データと最も一致するように選択されている。

In the equation, whiteness is defined by equation (1), and color appearance is defined by equation (6). The parameter “100” is selected such that the reference blackbody illuminator obtains a baseline value of 100, as with other illumination metrics. The “50” parameter is selected to adjust the LPI change to the same magnitude as the CRI. For example, a typical neodymium incandescent lamp is deducted by about 20 points in the CRI system, and the CRI can be about 80 compared to the standard CRI = 100, while the LPI system gives about 20 points to the same neodymium incandescent lamp. The LPI can be about 120 with respect to the standard LPI = 100. The weighting factors of 38% whiteness and 62% color appearance are selected to best match the viewer's preference data.

  An alternative LPI “master” equation is simply a combination of equations (1), (6) and (7), but is shown as equation (8).

上に例示されるマスター式という言葉でＬＰＩを言い換える目的は、当業者が不要な実験を行わずに本開示の手引きを用いて色科学において通常理解されるパラメータから導くことのできる値をこの新規な指標が提供することを示すことである。ＬＰＩはＮＳＶとともに増加するが、ＨＤＶが増加すると減少する。それとは別に、ＬＰＩはＤｕｖが「白色ライン」に近づくにつれて増加する。一部の実施形態では、達成できるＬＰＩの最大値は約１５０であり、白色度＝１及びカラーアピアランス＝１に相当する。一部の実施形態では、ＬＰＩの理論的最大値＝１８１であり、ここで白色度＝１であり、カラーアピアランス＝２である。

The purpose of paraphrasing the LPI in terms of the master expression exemplified above is that this new value can be derived from parameters normally understood in color science using the guidance of the present disclosure without undue experimentation by those skilled in the art. Is to show what a good indicator provides. LPI increases with NSV, but decreases as HDV increases. Apart from that, the LPI increases as Duv approaches the “white line”. In some embodiments, the maximum LPI that can be achieved is approximately 150, corresponding to whiteness = 1 and color appearance = 1. In some embodiments, the theoretical maximum value of LPI = 181, where whiteness = 1 and color appearance = 2.

In short, the LPI metric can be determined in the following steps (although not necessarily in the following order):
(A) obtaining a spectrum of light emitted from the test illuminant as its spectral power distribution (SPD) having an accuracy of 1-2 nm or finer;
(B) obtaining a chromaticity point (color temperature and Duv) from the SPD of the test illuminant;
(C) calculating a whiteness component from Duv using equation (1);
(D) obtaining a reference spectrum from the color temperature of the test illuminant;
(E) calculating chromaticity points for all 1600 Munsell colors in the CIELAB color space for both the reference illuminant and the test illuminant;
(F) calculating a color rendering vector of the test illuminant relative to the reference spectrum;
(G) calculating a net saturation value and a hue distortion value using Equation (3) and Equation (5), respectively;
(H) calculating the color appearance component using equation (6) and (i) integrating the whiteness component of step (c) and the color appearance component of step (h) and using equation (7) Obtaining LPI.

  In one or more embodiments, the whiteness of step (c) is calculated in parallel with the color appearance calculation of steps (d)-(h). The whiteness and color appearance are then used as inputs for the final stage (i).

  LPI objectively defines a quantitative color preference metric that most closely correlates to a limited population of observers for whom color preference data is available. It can also be quantified using a novel combination of data and existing color metrics that are somewhat weak but acceptable strongly correlated. As suggested by the LPI equation, existing color metrics that represent saturation and chromaticity points separately for BBL may approach the viewer's color preference response within some limits of the color space. I can expect. Those limits are incorporated into the definition of the LPI metric using numerical penalties applied in the LPI algorithm if any of several limits are compromised as described in the LPI description above. The LPI can further combine the effects of saturation and chromaticity points with each optimal weight to provide a single metric rather than multiple metrics, the single metric being the target and It has been confirmed that it is useful as a single parameter optimization response that allows the design of a spectrum that predicts the color preference response from the observer. None of the existing color metrics alone provide a correlation with the viewer's color preference as well as an LPI metric, but the separation between the peak or dominant wavelength of the YG phosphor and the red phosphor is an LPI metric. And the Duv unit of measure closely approximates the chromaticity point portion (ie, whiteness) of the LPI metric. In some embodiments, only a single type of phosphor (limited to YAG: Ce phosphors with various peak and dominant wavelengths) is used to provide YG emission to the source SPD, whereas Thus, two types of phosphors (a narrow band with a single peak wavelength and a broadband with various peak wavelengths) can be used to provide red emission in the SPD of the light source. In one or more embodiments, the separation between the peak or dominant wavelength of the YG phosphor and the peak wavelength of the red phosphor fixes the peak wavelength of the red phosphor while changing the dominant wavelength of the YG phosphor. And thereby quantifying by providing a direct unit of measure of separation between the YG phosphor and the red phosphor. For this reason, the inventors have used a blue LED, YG YAG as a very high-similar alternative to the more accurate LPI metric, depending on the dominant wavelength of the YG phosphor and the chromaticity point Duv in the CIE 1960u-v color space. An alternative can be chosen to describe the color preference of a light source comprising a Ce phosphor and an NR or BR phosphor with a given peak wavelength. This is because some practitioners calculate the dominant wavelength and Duv response of the YG phosphor rather than calculating the LPI response, even if all the details necessary to calculate the LPI response are available. There is an advantage that can be seen as simple.

Conventional lamp types include incandescent, halogen, and LEDs that use Nd-doped glass that absorbs some of the yellow light from the spectrum emitted from the light source, compared to similar lamps that do not absorb by Nd. Improve color preference. FIG. 5 shows an incandescent or halogen light source 500 that includes one or more incandescent or halogen coils 502 within a glass dome 504. In some embodiments, the glass dome 504 may be doped with neodymium oxide (Nd ₂ O ₃ ) as provided for incandescent and halogen lamps of the GE Reveal® type. Light emitted from one or more coils is generally similar to light in a black body spectrum with a correlated color temperature (CCT) between about 2700K and about 3200K. This CCT range is sometimes referred to as the bulb color. Since the Nd-doped glass dome 504 serves to filter out the light in the yellow portion of the color spectrum, the light traveling through the glass dome 504 of the light source 500 is emitted from the same light source that does not have an Nd glass filter. Compared to, it has an improved color preference or color saturation or color contrast generally preferred by human observers.

  FIG. 6a shows a plot 600 of relative light output versus wavelength (or spectral power distribution (SPD)) of the incandescent light source 500 of FIG. 5 with CCT = 2695K and a SPD plot 602 of the same CCT = 2695K black body light source. A black body illuminant is generally considered as a reference light source to be compared with a test light source when calculating a color measurement of the test light source for a test light source with CCT <5000K (for CCT> 5000K, the daylight spectrum is Commonly used as a reference). As a reference light source, a value of CRI = 100 is assigned to the black body light emitter. In order to maintain consistency, the black body is similarly assigned 100 reference values of the LPI metric. Since the incandescent SPD and the black body SPD are quite similar, the values of the 2695K incandescent light source are CRI = 99.8 and LPI = 99.8. In the case of CRI, the value of 99.8 is approximately equal to the maximum possible value of CRI = 100, so the incandescent light source has nearly ideal color rendering (or color “fidelity”) according to the CRI metric. For LPI, a value of 99.8 is considered a neutral value, not a maximum value. In some embodiments, values of LPI much lower than 100 are possible, so that a typical observer would be less likely to like such a light source than an incandescent light source, but about LPI = Much higher values up to 150 are possible, so that a typical observer is expected to prefer such a light source much more than an incandescent light source. The CRI metric quantifies the degree to which the light source renders eight pastel test colors exactly as the blackbody standard, so it is a “fidelity” metric for a limited range of colors in the color space. is there.

  FIG. 6b shows an SPD plot 600 of an incandescent light source with CCT = 2695K and obtained by filtering the light of the incandescent light source 500 with Nd-doped glass, CRE = 2755K, CRI about 80, LPI about 120 A SPD plot 604 of a trademark type incandescent light source is shown. The difference between these two SPDs is entirely due to the absorption of light by the Nd-doped glass, most of which occurs in the yellow range from about 570 nm to about 610 nm, with a weaker absorption of about 510 nm to about 540 nm green. Occurs in range. In one or more embodiments, the color preference benefits resulting from Nd absorption result from yellow absorption.

The SPD can be plotted on an absolute scale of light intensity, eg, in watts / nm or watts / nm / cm ² or other aspects of radiation, or described in relative units, sometimes herein. Thus, it can be plotted normalized to the peak intensity. Normalized SPD is such that the illuminance of the illuminated object or space is in the range of normal photopic vision (ie, greater than about 10-100 lux and up to about 10,000 lux (lux = lumens / Assuming m ² )), it is sufficient to calculate all color measurement features of the light source. Accumulating the SPD curve information allows precise calculation of all color measurements and light measurement responses of the light source.

  The incandescent lamp SPD plot 600 shown in FIG. 6a shows that it is an exceptionally well balanced light source since there are no significant spikes or holes at any wavelength. Such a smooth curve closely matches the curve of a black body curve with the same CCT and exhibits outstanding color fidelity capability. The blackbody spectrum is defined as having full color rendering on the CRI scale, ie CRI = 100. The CRI of incandescent lamps is generally about 99. The CRI of Nd-incandescent lamps is generally about 80. Despite the low CRI, most observers prefer the color rendering of Nd-incandescent lamps over incandescent lamps, especially for applications where organic matter such as people, food, wood, textiles, etc. is irradiated.

  Compared to some electrical light sources, sunlight shows a lot of energy in the blue and green parts of the spectrum, thereby making it a cold (ie high CCT) light source with a high color temperature (about 5500 K). . Thus, SPD charts are useful for understanding how the color composition of the light output of various lamps is different.

  Some conventional lamp types include Nd-doped glass that absorbs a portion of yellow light from the spectrum emitted from the light source, which improves the color preference over similar lamps that do not absorb yellow. One or more LEDs are used. FIG. 7a shows a Reveal® type LED light source 700 including one or more LEDs (FIG. 7b), and FIG. 7b is an exploded view of the light source 700 of FIG. 7a. An LED (light emitting diode) is an example of a solid state lighting (SSL) component, such as an incandescent bulb that uses an electrical filament, or a fluorescent or high intensity discharge tube that uses plasma and / or gas. As illumination sources instead of conventional light sources, semiconductor LEDs, organic LEDs or polymer LEDs can be included.

Referring to FIG. 7b, a light engine 712 comprising LEDs 706 and 708 and a printed circuit board 710 fitted with LEDs can be attached to the housing 704 so that when assembled, the LEDs 706 and 708 are neodymium oxide (Nd ₂ O ₃ ). , So that most or all of the light emitted from the LEDs 706 and 708 passes through the dome 702. It should be understood that FIGS. 7a and 7b depict only one example of an LED lamp that utilizes one or more solid state lighting components that provide illumination when powered. Accordingly, the specific components depicted in FIGS. 7a and 7b are for illustrative purposes only, and one of ordinary skill in the art will recognize various other components that may depend on the intended use and / or other considerations. It will be appreciated that any shape and / or size can be utilized. For example, the housing 704 may be of different sizes and / or shapes, and the solid state lighting components 706 and 708 may be directly and / or indirectly connected to it during assembly.

  FIG. 8 shows a plot 800 of a known spectral power distribution (SPD) of a bulb-colored LED lamp comprising a plurality of blue LEDs each exciting a YG YAG phosphor and a broadband red nitride phosphor whose emission strongly overlaps with the YAG phosphor. A graph including a broken line) is shown. This results in a very intense emission in the yellow spectrum and the mixed light has CCT = 2766K, CRI = 91 and LPI = 97. FIG. 8 also shows a SPD plot 810 (solid line) of a Reveal® type LED light source with CCT = 2777K, CRI = 91 and LPI = 111. The light emitted from the LED includes light from a blue LED 802 having a peak wavelength in a range of about 400 to about 460 nm (for example, royal blue InGaN) and a phosphor material (for example, YAG: Ce phosphor by blue light emission from the LED). YG light 804 having a peak emission in the range of about 500 to about 600 nm obtained by excitation of) and possibly by excitation of another phosphor (eg nitride or sulfide phosphor) by blue emission from the LED It can consist of a mixture with red light 806 having a peak emission in the range of about 600 to about 670 nm. The portion of blue light generated by the blue LED that is not absorbed by the phosphor material is combined with the light emitted from the phosphor material to provide light that appears nearly white to the human eye. The spectrum of the mixed light is similar to that of the black body spectrum, but may include a depression in the wavelength region between the emission of the blue LED and the emission of the YG phosphor. In some embodiments, the light source may have a correlated color temperature (CCT) between about 2700K and about 3200K (bulb color) or the light source has a higher CCT, perhaps on the order of about 10,000K or more. It may be higher or lower CCT, perhaps on the order of about 1800K or lower. The Nd glass serves to filter out the light in the yellow portion 808 of the color spectrum that can be generated by the YG and red phosphors, so that the light 810 emitted from the glass dome of the light source 700 (all of the solid line plot). Has an improved color preference or color saturation or color contrast or whiteness that is generally preferred by human observers compared to light 800 emitted from the same light source without an Nd glass filter.

  A special formulation of one or more low-pressure mercury (Hg) discharge lamps and a visible light emitting phosphor selected to reduce the amount of yellow light emitted by the light source (ie a fluorescent (FL) or compact fluorescent (CFL) light source) Several conventional lamp types, including, are also known to improve color preference compared to typical similar FL or CFL light source lamps that do not contain special phosphor formulations. FIG. 9 shows a Reveal® CFL light source 900 including a low pressure Hg discharge tube 902 coated with a customized mixture of phosphors 904 that has a relatively low emission in the yellow spectrum.

  FIG. 10 shows a graph including a known spectral power distribution (SPD) plot 1000 of the Reveal® CFL light source 900 of FIG. 9 with CCT = 2582K, CRI = 69 and LPI = 116. FIG. 10 also shows a plot 604 of the SPD of the Reveal® type incandescent light source of FIG. 5 with CCT = 2755K. The mixed light spectrum plot 1000 (from the CFL lamp) consists of many narrow emission bands and some broad emission bands designed to produce light that approximates a black body spectrum of CCT = 2582K. Compared to the Nd-Incandescent SPD plot 604, the red and green enhancements and yellow suppression are similar when considering the limitations of the red and green phosphors available for CFL products. The light source may also have a correlated color temperature (CCT) between about 2700K to about 3200K (bulb color). In some embodiments, the light source may have a higher CCT (eg, about 10,000K or higher) or a lower CCT (eg, about 1800K or lower). The mixed light spectrum plot 1000 of a light source 900 with relatively low emission in the yellow portion of the spectrum is an enhanced color that is generally preferred by human observers compared to light emitted from the same light source with a conventional phosphor mixture. It may have preference, color saturation, or color contrast.

  Some further conventional lamp types include one or more LEDs having green and red phosphors with peak wavelengths far enough to create a depression in the yellow wavelength range, such as meat, vegetables and Used in grocery store applications to highlight the color of agricultural products (eg fruits). FIG. 11 shows the SPD of a known light source with green and red phosphors with peak wavelengths far enough to create a depression in the yellow wavelength range, CCT = 2837K, CRI = 74 and LPI = 124. A graph including plot 1100 is shown. The light emitted from the LED is obtained by excitation of the green phosphor with a blue wavelength 1102 having a peak wavelength in the range of about 400 to about 460 nm, and the green phosphor excited by the blue emission from the LED, caused by the emission from the blue LED. A green emission 1104 having a peak wavelength in the range of 500 to about 580 nm and a FWHM 1108 of about 80 nm, and a peak emission in the range of about 600 to about 670 nm obtained by excitation of the red phosphor with blue emission from the LED. It can consist of a mixture with red emission 1106 with FWHM 1110 of 100 nm. The portion of the blue light generated by the blue LED that is not absorbed by the phosphor material is combined with the light emitted from the green and red phosphor materials to provide light that appears nearly white to the human eye. The spectrum of the mixed light may have a depression in the wavelength region between the blue LED emission 1102 and the green phosphor emission 1104, and the yellow between the green phosphor emission 1104 and the red phosphor emission 1106. A second recess may be included in the wavelength range. The light source may also have a CCT between about 2700K and about 6000K, or have a higher CCT (eg, about 10,000K or more) or a lower CCT (eg, about 1800K or less). Sometimes. A decrease in the emission of the yellow portion of the SPD plot 1100 due to the separation of the 528 nm green phosphor emission 1104 peak and the 645 nm red phosphor emission 1106 peak results in a light source spectrum plot 1100, and LPI Becomes approximately 124. The relatively high LPI value of this known light source is due to the relatively narrow FWHM (about 80 nm) and the blue shifted peak of the green phosphor (about 528 nm), which is the YG YAG: Ce fluorescence of the embodiments of the present disclosure. It is not the same as the body composition. As shown in the 25 different YAG phosphor embodiments described in one or more embodiments below, the FWHM of the YG YAG: Ce phosphor is typically a slightly broader range of FWHM from about 110 to about 120 nm. And a peak wavelength region of about 530 nm to about 560 nm.

FIG. 12 includes a blue LED that peaks at around 450 nm, a Gaussian approximation to a YG phosphor with a peak at around 545 nm and a FWHM of around 80 nm, and a red LED that peaks at around 635 nm and has a FWHM of around 20 nm. , CCT = 2700K and Duv = −0.010, and shows a graph of the SPD of an ideal LED light source that yields a nearly maximum practical LPI value of about 145 spectrum to the lighting preference index (LPI) metric In order to better understand and communicate the effects of component selection, a detailed experimental design (DoE) was performed using a spectral model. These experiments allowed the identification of optimal spectral features to maximize LPI and typical observer color preference responses and guide future lighting product designs. This DOE is a commercially available or easily manufactured luminescent component comprising the use of a yellow-green (YG) garnet phosphor and either a narrow-band red (NR) or a broadband red (BR) phosphor Designed specifically to identify the composition of the luminescent component to improve the LPI of the light source.

  Each spectrum consists of three components (nominally blue, green and red) superimposed on one composite spectrum. As shown in FIG. 13, in some embodiments, the blue light emitting component 1302 is a component of a blue LED having a peak emission of about 450 nm and having a FWHM 1304 of about 15 nm. This wavelength was chosen as representative of typical blue LEDs currently used in most white light sources. Other suitable blue light emitting components having features such as peak wavelengths in the range of about 400 nm to about 460 nm and FWHM <about 50 nm may be used. The LPI color metric is relatively less sensitive to blue emission than green and red emission. This can be seen from FIG. In this figure, the blue 102 retinal response is clearly distinguished from green 104 and red 106, but the green and red responses are not distinct from each other. Since LPI is relatively insensitive to the blue feature, this DOE result has a peak wavelength in the blue or violet range (eg, about 400 to about 460 nm) and any FWHM below about 50 nm. It can be expected to represent the result obtained with a blue light source.

In one or more embodiments, the green component has five different YG YAG fluorescence having peak wavelengths in the range of about 540 nm to about 547 nm, representing the normal range of commercially available or easily manufactured YAG phosphors. It can be modeled using a family of body luminescence (FIG. 14). In addition, to find a trend that allows further optimization of the LPI response, the emission spectrum of the green component is varied by +5 nm, -5 nm, +10 nm, and -10 nm from the actual emission spectrum of each of the five commercially available phosphors. Let Therefore, in total, DoE has 25 different green components (= 5 phosphors * (one unshifted +4 shifted spectrum)) with a total peak wavelength range of about 530 nm to about 557 nm. included. The full width at half maximum (FWHM) of each shifted green component, eg 1404, is held constant and is equal to the FWHM of a corresponding non-shifted commercial phosphor, eg 1402, in the range of about 112 nm to about 115 nm. is there. In this specification, the YG YAG phosphor is composed of 1) one or more elements selected from the group consisting of Y, Lu, Sc, La, Gd, Tb, and Sm, and 2) Al, Ga, and In. A family of phosphors having a garnet phosphor material selected from the group and comprising one or more elements activated by Ce may be included, the garnet phosphor comprising yttrium aluminum garnet (YAG) doped with Ce Y ₃ Al ₅ O ₁₂ ), ie YAG: Ce ³⁺ .

In one or more embodiments, the red component may be modeled using a family of four different BR nitride phosphors (FIG. 15) and an NR phosphor (FIG. 16). The BR nitride phosphor is generally represented by a general formula of CaAlSiN ₃ : Eu ²⁺ . These BR nitride phosphor materials strongly absorb UV and blue light and can emit efficiently between about 600 nm and 680 nm, for example, with a FWHM of about 80 nm to about 120 nm (eg, 1504). (Eg 1502), which results in a very strong light emission in the dark red. NR phosphors (FIG. 16) are known, some of which are described in composite fluoride materials activated by Mn ⁴⁺ , eg US Pat. No. 7,358,542, US Pat. No. 7,497,973 and US Pat. No. 7,648,649. And so on. The Mn ⁴⁺ doped phosphor has the formula A _x [MF _y ]: Mn ⁴⁺ , where A (alkali) is Li, Na, K, Rb, Cs or combinations thereof and M ( Metal) is Si, Ge, Sn, Ti, Zr, AI, Ga, In, Sc, Hf, Y, La, Nb, Ta, Bi, Gd or a combination thereof, and x is an [MF _y ] ion. Y is 5, 6, or 7. These materials absorb blue light strongly, emit efficiently between about 610 nm and 660 nm (eg, 1602) and have little dark red or near infrared emission, which has a FWHM much lower than 30 nm 1606, generally, it is about 5 nm. Even if this particular NR phosphor is composed of several narrow peaks, the total width encompassing the main peak is still much lower than 30 nm, generally about 20 nm as shown at 1604. In one or more embodiments, the NR phosphors of the present invention have a peak wavelength at about 631 nm and represent commercially available PFS as described in US Pat. No. 7,358,542, US Pat. No. 7,497,973 and US Pat. No. 7,648,649. . Thus, in one or more embodiments, in a DoE implementation that includes only the NR phosphor without the BR phosphor, the NR phosphor consisted of only a single unique red component. In other embodiments, this particular NR phosphor may be another NR phosphor having a similar peak wavelength in order to benefit from a color preference very similar to that provided by the NR phosphor. May be replaced.

  In one or more embodiments, the broadband red component has a peak wavelength range of about 620 nm to about 670 nm, representing a typical range of commercially available or easily manufactured broadband red nitride phosphors. It can be modeled using different BR nitride phosphor emission families. Thus, in one or more embodiments, in implementations that include only BR nitride phosphors without NR phosphors, the BR nitride phosphors included four different red components. Furthermore, in order to find a tendency to allow further optimization of the LPI response, the emission spectrum of the red component is +5 nm, −5 nm, +10 nm and −− from the actual emission spectrum of each of the four commercially available BR nitride phosphors. Change by 10 nm. Thus, in one or more embodiments, 20 (= 4 phosphors * (one non-shift + 4 shifted spectra)) different BR components with a total peak wavelength range of about 610 nm to about 680 nm. I moved it. The full width at half maximum (FWHM) of each of the shifted BR components is held constant and is equal to the FWHM of the corresponding non-shifted commercial phosphor, which ranges from about 86 nm to about 93 nm. FIG. 15 shows the SPD of the four unshifted red components of the 20 red components used.

  In one or more embodiments, DoE was divided into three groups distinguished by red phosphors. Group 1 contains only NR PFS phosphors (YAG + PFS), Group 2 contains each of the 20 BR nitride phosphors separately (YAG + Nit), representing commercially available red nitride phosphors, Group 3 It consists of three ratios of BR power versus NR power (total emission power for all red emission wavelengths as described in FIGS. 15 and 16) in 25% increments, with a single NR phosphor and For each of the 20 BR nitride phosphors combined (YAG + PFS + Nit), (BR power) / (BR power + NR power) ≡BR / R≡n = 0.25, 0.50, 0.75. We refer to these three subsets of Group 3 DoE as Group 3a (n = 0.25), Group 3b (n = 0.50) and Group 3c (n = 0.75). Note that the limited examples of n = 0 and 1 correspond to DoE for group 1 (YAG + PFS) and group 2 (YAG + Nit), respectively. Dividing DoE into three groups is a matter of convenience for conveying the results. In fact, the ratio BR / R = n can have a continuous range of 0.0 to 1.0, and a limited example of n = 0 and n = 1 is DoE Group 1 (YAG + PFS) and Each corresponds to a group 2 (YAG + Nit) portion. Group 3 is represented as having three distinct levels, n = 0.25, 0.50, and 0.75, but the LPI transfer function over a continuous range of 0.0 <n <1.0. By actually providing and combining the results of groups 1 and 2, the LPI transfer function is provided in a continuous range of 0.0 ≦ n ≦ 1.0. A mixture of red nitride and PFS emitter may be used in one or more embodiments due to the trade-off between color measurement and photometric capabilities of an emitter having an NR emitter versus a BR emitter, thereby NR emitters can improve efficiency by reducing the radiation dose at the far tail wavelength of the photopic eye response curve, while BR emitters improve color rendering or color preference at the expense of efficiency. be able to.

  The ratio of emission power of the blue, green and red illuminants was adjusted to obtain two necessary degrees of freedom, uniquely defining the chromaticity point of the 1931 CIE color space, and similarly defining the SPD uniquely. DoE is 10 distinct chromaticity points, each of 2 CCTs (2700K and 3000K) and 5 Duv values: 0.000 (on blackbody locus), -0.005, -0.010 (whitebody) Near line), each at -0.015 and -0.020.

  Each of the 10 chromaticity points in each of the 3 groups produces all combinations of blue, green and red components, and each of the 10 chromaticity points of Group 1 DoE has 25 unique points. Combination (1 blue x25 green x 1 red), 500 unique combinations for each of the 10 chromaticity points of group 2 DoE (1 blue x25 green x 20 red) and 10 DoEs of group 3 Each of the chromaticity points yields 1500 unique combinations (one blue x25 green x20 red x3 red ratio), for a total of 2025 unique combinations in each of the three groups of 10 chromaticity points Combinations yielded a total of 20,250 unique combinations (SPDs) across 10 chromaticity points. We often refer to the entire set of 20,250 combinations as DoE. Next, a lighting preference index (LPI) value is calculated for each spectrum of DoE, including a blue LED, a YG YAG: Ce phosphor, and either a BR nitride phosphor or an NR phosphor. The trend and trade-off of LPI that can be realized from the LED light source being analyzed is analyzed.

The notable and unexpected result of DoE above is that any given DoE can be determined by closed-form analytical approximations using DoE's two independent variables: the dominant wavelength of the YAG phosphor (ie, Dom _YAG ) and Duv. The LPI (and thus the color preference of the observer) can be predicted sufficiently well for the red light emitters. To represent DoE results in terms of dominant wavelengths, FIGS. 17-21 serve to define each of DoE's 25 YG and 20 BR phosphors by their dominant wavelength. The peak wavelength of the light source is the wavelength at which the emission intensity is maximum, whereas the dominant wavelength is the wavelength of pure monochromatic light that most closely matches the hue (perceived color) of the light source. As depicted in FIG. 17a, the dominant wavelength of the light source is formally defined as a point 1704 on the spectral trajectory 1702 (perimeter of 1931 CIE color space 1700) (Wyszekki and Styles, Color Sciences: Concepts and Methods, Quantitative Data). Formula , Wiley-Interscience; see 2 edition (August 8, 2000)), where the vector starts at the colorless D65 chromaticity point 1706, passes through the chromaticity point 1708 of the test light source, and intersects the spectral trajectory 1702. Wavelengths, such as 580 nm 1712 along the spectral trajectory 1702, are classified in increments of 10 nm or more. In FIG. 17b, the chromaticity point of a commercial illuminant used in DoE is shown in 1931 CIE color space 1700. A blue LED 1722 having a peak wavelength of about 450 nm (as in FIG. 13), five YG YAG: Ce phosphors 1724 (as in FIG. 14) and a single NR phosphor 1726 having a peak wavelength of about 631 nm (FIG. 16). Street). FIG. 17c is the same as FIG. 17b, but shows four commercially available broadband red nitride phosphors 1728 (as in FIG. 15) used in DoE instead of a single NR phosphor.

  In FIG. 18a, the 25 YG phosphor chromaticity points 1834 used in DoE are shown in an enlarged view 1800 of the 1931 CIE color space. 5 commercial YG YAG: Ce phosphors and modified versions of each of the 5 commercial YG YAG phosphors. Here, the emission spectrum is shifted by +10 nm, +5 nm, −5 nm, and −10 nm and represents a wide range of different YG YAG phosphors that are systematically parameterized. In FIG. 18b, the chromaticity points 1844 of 22 commercially available YG YAG phosphors, which essentially represent the full range of currently available YG YAG: Ce phosphors, are the 25 of FIG. 18a used in DoE. An enlarged view 1800 of the 1931 CIE color space is shown along with the YG phosphor 1834. Comparing the chromaticity points of a group of 25 systematically parameterized YG phosphors used in DoE with 22 commercially available YG YAG: Ce phosphors, the currently available YG YAG: Ce phosphors It is clear that the range of is completely represented by DoE.

  In FIG. 19a, the chromaticity points 1938 of the 20 BR phosphors used in DoE are shown in an enlarged view 1900 of the 1931 CIE color space. Four commercially available broadband red nitride phosphors and modified versions of each of the four commercially available broadband red nitride phosphors. Here, the emission spectrum shifts by +10 nm, +5 nm, −5 nm, and −10 nm, representing a wide range of different BR phosphors that are systematically parameterized. In FIG. 19b, the chromaticity points 1948 of 14 commercially available broadband red nitride phosphors that basically represent the full range of currently commercially available broadband red nitride phosphors are shown in FIG. 19a as used in DoE. Included with 20 BR phosphors 1938. Comparing the chromaticity points of a group of 20 systematically parameterized BR phosphors used in DoE with 14 commercially available broadband red nitride phosphors, currently available broadband red nitride phosphors It is clear that the range of is completely represented by DoE.

  Considering that the peak wavelength of the light source is the wavelength at which the emission intensity is maximum, while the dominant wavelength is the wavelength of pure monochromatic light that most closely matches the hue (perceived color) of the light source, the phosphor It is useful to compare these two wavelength metrics that partially explain the color of FIG. 20 shows the relationship between the dominant wavelength and the peak wavelength for the 25 YG phosphors used in DoE. As shown herein, the dominant wavelength is usually longer than the peak wavelength for each of the YG phosphors. This is mainly because the phosphor emission is asymmetric. As can be seen in FIG. 14, each long wavelength tail of the emission spectrum is wider than the short wavelength tail, so the perceived hue of each spectrum has a wavelength longer than the peak wavelength of each YG phosphor. Predicted to be best represented by a monochromatic illuminant. FIG. 21 shows the relationship between the dominant wavelength and the peak wavelength for the 20 BR phosphors used in DoE. As shown herein, the dominant wavelength is usually shorter than the peak wavelength for each of the BR phosphors. This is mainly due to the fact that there is an extremely long wavelength of phosphor emission on the right side of each peak wavelength, as can be seen from FIG. Since the long wavelength tail extends far beyond the response wavelength of the eye (FIG. 1a), the left half of the emission spectrum affects the perceived hue more strongly than the right half of the spectrum. Thus, each spectrum can be expected to be best represented by a monochromatic phosphor having a wavelength shorter than the peak wavelength of each BR phosphor.

  Each of the embodiments herein may be described as having one blue light source, one yellow-green garnet phosphor, one narrow red downconverter and / or one wide red downconverter, One or more blue light sources may be used, one or more yellow-green garnet phosphors may be used, one or more narrow red downconverters may be used, and / or one or more broadband red downconverters may be used. Note that it may be done.

Group 1 DoE (YAG + PFS) includes all combinations of one blue LED, 25 YG YAG: Ce phosphors and one NR PFS phosphor, resulting in 25 unique emitter combinations (1 Bx25 YGx1 NR) is obtained, whereby the ratio of blue: green: red emission power of each of the 25 unique emitter combinations is 10 chromaticity points (2700K and 3000K; (Duv = 0.000, -0.005, -0.010, -0.015, -0.020) each resulting in 250 unique SPDs. In one or more embodiments, each normalized SPD has an illuminated object or space illumination within normal photopic range (ie, greater than about 10-100 lux, about 1 10000 to 10,000 lux (lux = lumens / m ² )) is sufficient to calculate all color measurement features of the light source. The target color measurement response, LPI, is plotted against Dom _YAG (x axis) and Duv (y axis) of the chromaticity point at 2700K in FIG. 22a. The LPI is plotted against Dom _YAG and Duv at a chromaticity point of 3000K in FIG. 22b. In one or more embodiments, the dominant wavelength of the yellow-green garnet phosphor (YAG in this example) is in the range of 559 nm to about 574 nm. In Figure 23, the Dom _YAG and Duv value of 250 unique SPD used in groups 1DoE, superimposed on the background shade of LPI contour 25 of the different Dom _YAG of each of the five different Duv Shown as a group. Other suitable Duv levels may be used. Similar contour plots can be presented for a continuum of Duv levels within the Duv range represented herein, and a similar trend is realized. The smooth curves of LPI shown in FIGS. 22a, b are obtained from fitting a statistically optimized ANOVA regression to the data, where LPI = f (CCT, Duv, Dom _YAG ) and four Including a polynomial of the order and all the resulting variable interactions, yields a transfer function with Adjusted R ² > 0.99. Those skilled in the art will recognize that a function having a higher-order expression than a fourth-order expression in an LPI contour line having an LPI value of 120 or more (assuming that a higher-order term equivalent to the fourth-order expression is included in the transfer function of the LPI Will also understand that there is a relative shortage and that there is a smooth transition between the contours shown, so the LPI transfer function facilitates the underlying 250 individual DoE implementations. It is reasonable to expect to represent continuously. The solution representing all 250 combinations of SPDs consisting of blue LEDs, YG YAG: Ce phosphors and NR phosphors is expressed by the transfer function LPI = f (CCT, Duv, Dom _YAG ) represented by the LPI contour map. Those skilled in the art will understand that it is described quantitatively with a very low error (R ² > 0.99). Thus, consider the transfer function represented by LPI contour diagram LPI = f (CCT, Duv, Dom YAG) is valid for all CCT, Duv and Dom _YAG within the bounded range of the different embodiments of the DoE It is done.

A specific SPD 2400 with a maximum LPI value of about 137 (corresponding to a Dom _YAG of about 559 _nm ), a Duv of about −0.010, and a CCT = 2700K group 1 DoE (YAG + PFS) is shown in FIG. The peak wavelength 2402 of the blue LED, the peak wavelength 2404 of the YG YAG: Ce phosphor of about 531 nm, and the peak wavelength 2406 of the NR PFS phosphor of about 631 nm are shown. In addition, a REVAL® incandescent lamp SPD 604 and a black body light emitter SPD 602 each having similar CCTs are compared. In particular, in one or more embodiments, an LPI of 140 or more is produced by a YAG and narrowband red downconverter having a preferred wavelength over the peak wavelength of a PFS phosphor fixed at 631 nm, or two or more having different peak wavelengths. This can be achieved by using a narrow band red down converter.

Figure 22a, b, both of 2700K and 3000K, if the chromaticity point of the light source is on the black body locus (Duv = 0.000), with all Dom _YAG (i.e. any commercial YG YAG: Ce phosphor But) demonstrates that LPI <120 (approximately the upper limit of LPI found in the prior art). As Duv decreases, LPI usually increases with all Dom _YAG , and Duv reaches a maximum of about -0.010 according to equation (1) (this Duv value maximizes the whiteness component of LPI). A considerable degree of LPI contour symmetry is obtained for the horizontal line of Duv = −0.010. When Duv moves from Duv = 0.000 to Duv = −0.010, the whiteness component of the LPI equation increases from 0 to 1, and the LPI increases by 19 points based on equation (7). Similarly, when Duv moves from Duv = −0.010 to Duv = −0.20, the whiteness component decreases from 1 to 0 and the LPI decreases by 19 points.

For a given Duv, LPI, which increases almost monotonically as Dom _YAG decreases, mainly reduces the large yellow emission, or the perceived saturation of the red-green opposite color and the blue-yellow opposite color. Creating a depression in the yellow portion of the spectrum (eg, about 570 to about 600 nm), which may be due to separation between the wavelengths of the YG and narrowband red emitters. For two main trends in FIGS. 22a, b, ie, for this set of commercially available phosphors (blue LED, YG YAG: Ce phosphor and NR phosphor), the LPI has a maximum at Duv of about −0.010. And the LPI tends to reach a maximum at a shorter Dom _YAG , so the LPI contours only contain the term Dom _YAG as an alternative to Duv and color appearance to define whiteness. It is suggested that it can be approximated in the analytical formula of the closed form that contains it. In general, due to the absence of higher order irregularities in LPI contours having values of 120 or greater, such analytical approximations to those higher LPI contours may include most or all of the LPI contours generated by DoE. It is suggested that there is a relatively simple form that applies to. In one or more embodiments, the visual appearance of the high LPI contour suggests that the ellipse may provide the best fit for the high LPI contour. The general form of equation (9) below resulted in a match between the exact LPI contour and the elliptical approximation of any LPI contour in FIGS. 22a, b with more than 120 LPI.

ＣＣＴに対するＬＰＩの傾向は、式（９）の単純な線形項によって正確に記載することができる。式（９）の係数ａ及びｂの値は、下の表２に図２２ａ、ｂの１２０以上の各々のＬＰＩ値に関して記載される。

The tendency of LPI to CCT can be accurately described by a simple linear term in equation (9). The values of coefficients a and b in equation (9) are listed in Table 2 below for each LPI value greater than 120 in FIGS. 22a, b.

表２のＬＰＩ＝１２０の列からａ、ｂの値を式（９）に代入することにより、ＬＰＩ＝１２０の正確な等高線への楕円近似のための明示公式は、下の式（９ａ）となる。

By substituting the values of a and b from the column of LPI = 120 in Table 2 into equation (9), the explicit formula for ellipse approximation to the exact contour line of LPI = 120 is the following equation (9a): Become.

式（９ａ〜ｄ）により、ＣＣＴ＝２７００について図２５ａに示し、ＣＣＴ＝３０００Ｋについて図２５ｂに示す破線の楕円が得られる。図２５ａ、ｂを見て分かるように、破線の楕円近似は、１２０以上の値をもつどのＬＰＩ等高線上のどの位置でもＬＰＩが２ポイントを超えない量だけ、それぞれの正確なＬＰＩ等高線から逸脱する。約５ポイント未満、特に約２ポイント未満のＣＲＩ値の違いは、通常、大部分の観察者には知覚されないことが知られている。また、ＬＰＩを扱う研究において、約５ポイント未満、特に約２ポイント未満のＬＰＩ値は通常大部分の観察者には知覚されないことも観察されている。ＣＲＩで得られるものと同程度の定量的区別をＬＰＩで得るためにＬＰＩスケールは意図的にＣＲＩスケールに対して比例しているように作られているので、これは予測される。

Equations (9a-d) yield the dashed ellipse shown in FIG. 25a for CCT = 2700 and shown in FIG. 25b for CCT = 3000K. As can be seen in FIGS. 25a and b, the elliptical approximation of the dashed line deviates from each exact LPI contour by an amount that the LPI does not exceed two points at any position on any LPI contour with a value of 120 or greater. . It is known that differences in CRI values of less than about 5 points, especially less than about 2 points, are usually not perceived by most observers. It has also been observed in studies dealing with LPI that LPI values below about 5 points, especially below about 2 points, are usually not perceived by most observers. This is expected because the LPI scale is intentionally made to be proportional to the CRI scale in order to obtain a quantitative distinction with the LPI that is comparable to that obtained with the CRI.

  In FIG. 26a, the area described in Equation 9a for the LPI = 120 contour line of CCT = 2700 in group 1 DoE (YAG + PFS) is shown in shaded black. Similarly, in FIGS. 26b-d, the regions described by equations 9b-d for the contour lines of LPI = 125, 130 and 135 are shown in black shades.

Group 2 DoE (YAG + Nit) includes all combinations of one blue LED, 25 YG YAG: Ce phosphors and 20 BR nitride phosphors, resulting in 500 unique phosphor combinations ( 1 B × 25 YG × 20 BR), so that the ratio of blue: green: red emission power for each of the 500 unique emitter combinations is 10 chromaticity points. (2700K and 3000K; Duv = 0.000, -0.005, -0.010, -0.015, -0.020) to achieve each of the resulting 5000 unique SPDs Bring. Each normalized SPD has an illuminated object or space illumination within the normal photopic range (i.e., greater than about 10-100 lux, about 1,000 to about 10,000). Assuming up to lux (lux = lumens / m ² )), it is sufficient to calculate all color measurement features of the light source. In the example of a BR phosphor with a peak wavelength (Peak _Nit ) of 610 nm, the desired color measurement response, LPI, is shown in FIG. 27a for the chromaticity points Dom _YAG (x axis) and Duv (y axis) at 2700K Is plotted. The Peak _Nit range used in Group 2 DoE is shown in FIG. 21 to be about 610 nm to about 680 nm, including 20 different BR phosphors in that range.

As shown in FIG. 23 and used in group 1 DoE, 250 unique combinations of Dom _YAG and Duv values, each consisting of 25 different Dom _YAG values of 5 different Duv values, are 20 different BR phosphors. The same 250 unique combinations of Dom _YAG and Duv used in group 2 DoE in combination with each of. The fine spacing between the Dom _YAG value on the x-axis and the Duv value on the y-axis of the 250 unique SPDs used in Group 1 DoE can actually lead to smooth interpolation between the individual SPDs used in DoE. It was found. Five Duv levels were selected to illustrate the effect of chromaticity points or Duv on LPI. Other suitable Duv levels may be used. In one or more embodiments, similar contour plots may be presented for a continuum of Duv levels within the Duv range represented herein, and a similar trend is realized. The smooth curve of LPI shown in FIG. 27a is obtained from fitting a statistically optimized ANOVA regression to the data, where LPI = f (CCT, Duv, Dom _YAG , Peak _Nit ), Including a polynomial equivalent to the quartic and all the resulting variable interactions, yields a transfer function with Adjusted R ² > 0.99. Those skilled in the art will understand that LPI contours with LPI values of 120 or more lack the ability to include higher order equations than quartics and that there is a smooth transition between the indicated contours. In addition, the solution representing all 5000 combinations of SPDs consisting of blue LED, YG YAG: Ce phosphor and BR phosphor is the transmission represented by the LPI contour diagram of FIG. 27a when Peak _Nit = 610 nm. It will be understood that the function LPI = f (CCT, Duv, Dom _YAG , Peak _Nit ) is explained quantitatively with very low error (R ² > 0.99). Similarly, the transfer function LPI = f (CCT, Duv, Dom _YAG , Peak _Nit ) solved at Peak _Nit = 610, 620, 630, 640, 650, 660, 670 and 680 nm in 10 nm increments at CCT = 2700K is It is represented by the LPI contour map of FIGS. 27a-h; at 3000K, it is represented by the LPI contour map of FIGS.

The SPD with the largest LPI (approximately 142) among the 2500 SPDs of 2700K in group 2 DoE is shown in FIG. A specific SPD 2900 with a maximum LPI value of about 142 (corresponding to a Dom _YAG of about 559 _nm ), a Duv of about −0.010, and a CCT = 2700K group 2 DoE (YAG + Nit) is shown in FIG. A peak wavelength 2902 for a blue LED, a peak wavelength 2904 for a YG YAG: Ce phosphor at about 531 nm, and a peak wavelength 2906 for a BR nitride phosphor at about 680 nm are shown; and further, reveal® each having a similar CCT A comparison is made between an incandescent lamp SPD 604 and a black body light emitter SPD 602.

Figure 27a~h and 28a~h in both 2700K and 3000K, if the chromaticity point of the light source is on the black body locus (Duv = 0.000), with all Dom _YAG (i.e. any commercial YG YAG : Even with Ce phosphor), it proves difficult to achieve LPI> 120. Only long wavelength nitrides (Peak _Nit > 660 nm) and short wavelength YAG (Dom _YAG <562 nm) allow LPI> 120 on black bodies. As Duv decreases, LPI usually increases with all Dom _YAG , and Duv reaches a maximum of about -0.010 according to equation (1) (this Duv value maximizes the whiteness component of LPI). A considerable degree of LPI contour symmetry is obtained for the horizontal line of Duv = −0.010. When Duv moves from Duv = 0.000 to Duv = −0.010, the whiteness component of the LPI equation increases from 0 to 1, and the LPI increases by 19 points based on equation (7). Similarly, when Duv moves from Duv = −0.010 to Duv = −0.020, the whiteness component decreases from 1 to 0 and the LPI decreases by 19 points.

For a given Duv, LPI, which increases almost monotonically as Dom _YAG decreases and Peak _Nit increases, mainly reduces large yellow emission, or the opposite of red-green and blue-yellow Creating a depression in the yellow portion of the spectrum (eg, about 570 to about 600 nm) that enhances the perceived saturation of the color, possibly due to separation between the wavelengths of the YG and BR emitters. For the three main trends in FIGS. 27a-h and 28a-h, ie this set of commercially available phosphors (blue LED, YG YAG: Ce phosphor and BR nitride phosphor), the LPI is about −0. LPI _contours tend to be maximum at Duv of 010, and LPI tends to be maximum at shorter Dom _YAG , and LPI tends to be maximum at longer Peak _Nit Is suggested to be approximated in a closed-form analytical expression containing only Dom _YAG and Peak _Nit terms as an alternative to Duv and color appearance to define whiteness.

Similar to group 1 DoE's equation (9), which is a general form of elliptical approximation to the group 2 DoE LPI curve, equation (10) below shows the exact LPI contours and LPIs of 120 or more. A match within 1 or 2 points in the LPI between h and the elliptical approximation of any LPI contour in FIGS. Since the transfer function of the LPI of group 2 has an additional variable, Peak _Nit , compared to group 1, equation (10) is necessarily more complex than equation (9).

式（１０）は、例えば、２７００Ｋ及びＰｅａｋ_Nit＝６４０ｎｍの例の図３０ａにおいて、破線で表示した１２０をプロットするために使用することができる。下の表３の１２０の列の係数、ａ_i及びｂ_i（ｉ＝１、２、３）及びλ₀＝６３０（そのためＰｅａｋ_Nit−λ₀＝１０）の値は、ＣＣＴ＝２７００とともに式（１０）に挿入すると、下の式（１０ａ）となる。

Equation (10) can be used, for example, to plot 120 shown as a dashed line in FIG. 30a for the example of 2700 K and Peak _Nit = 640 nm. The values of 120 columns in Table 3 below, the values of a _i and b _i (i = 1, 2, 3) and λ ₀ = 630 (so that Peak _Nit −λ ₀ = 10) are When inserted into 10), the following equation (10a) is obtained.

同様に、表３の係数、ａ_i及びｂ_i（ｉ＝１、２、３）及びλ₀の値は、式（１０）に代入すると、ＣＣＴ＝２７００Ｋの図３０ａ〜ｅ及びＣＣＴ＝３０００Ｋの図３１ａ〜ｅ中の破線曲線の各々を生じ、図２７ｄ〜ｈ及び図２８ｄ〜ｈからの１２０以上の各々のＬＰＩ値に対応する。図２７ａ〜ｃ及び２８ａ〜ｃから明らかであるように、１２０以上のＬＰＩの値はＰｅａｋ_Nit＝６１０、６２０及び６３０ｎｍの場合にはないので、図３０ａ〜ｅ及び３１ａ〜ｅは、Ｐｅａｋ_Nit＝６４０、６５０、６６０、６７０及び６８０ｎｍの値に対応する。

Similarly, the coefficients of Table 3, a _i and b _i (i = 1, 2, 3) and λ ₀ are substituted into equation (10), and CCT = 2700K FIGS. 30a-e and CCT = 3000K Each of the dashed curves in FIGS. 31a-e result and correspond to each of the 120 or more LPI values from FIGS. 27d-h and FIGS. 28d-h. As is apparent from FIGS. 27a-c and 28a-c, LPI values greater than 120 are not in the case of Peak _Nit = 610, 620 and 630 nm, so FIGS. 30a-e and 31a-e show Peak _Nit = Corresponding values of 640, 650, 660, 670 and 680 nm.

Group 3DoE (YAG + PFS + Nit) includes all combinations of the above one blue LED, 25 YG YAG: Ce phosphors and 20 BR nitride phosphors, resulting in a BR power pair in 25% increments. Each illuminant (one Bx25 YGx1 NRx20) with three different ratios of NR power (emission power totaling all wavelength ranges of red emission as provided in FIGS. 15 and 16) BR) of 500 unique combinations were obtained. Therefore, (Nit power) / (Nit power + PFS power) ≡n = 0.25, 0.50, 0.75; and (PFS power) / (Nit power + PFS power) ≡p = 0.75, 0.50 0.25, where n + p = 1 for each of the 20 BR nitride phosphors. As used herein, these three subsets of group 3DoE may be referred to as group 3a (n = 0.25), group 3b (n = 0.50) and group 3c (n = 0.75). . In one or more embodiments, the limited examples of n = 0 and n = 1 correspond to group 1 (YAG + PFS) and group 2 (YAG + Nit) DoE, respectively. In one or more embodiments, at each of three different ratios of BR power to NR power, the ratio of blue: green: red emission power of each of the 500 unique emitter combinations is 10 chromaticity points. (2700K and 3000K; Duv = 0.000, -0.005, -0.010, -0.015, -0.020) each resulting in 15000 unique SPDs can get. In one or more embodiments, each normalized SPD has an illuminated object or space illumination within normal photopic range (ie, greater than about 10-100 lux, about 1 10000 to 10,000 lux (lux = lumens / m ² )) is sufficient to calculate all color measurement features of the light source. The range of Peak _Nit used in group 3 DoE shown in FIG. 21 is about 610 nm to about 680 nm, and the range includes 20 different BR phosphors.

The target color measurement response, LPI, in FIGS. 32a-h, has an NR phosphor with a peak wavelength of 631 nm and a peak wavelength (Peak _Nit ) of 610 nm (FIG. 32a) to 680 nm (FIG. 32h) in 10 nm increments. For an example of the ratio of Nit power to PFS power given BR phosphor and n = 0.25, so p = 0.75, the chromaticity point Dom _YAG (x axis) and Duv (y axis) at 2700K Is plotted against.

The desired colorimetric response, LPI, in FIGS. 33a-h, has a NR phosphor with a peak wavelength of 631 nm and a peak wavelength (Peak _Nit ) of 610 nm (FIG. 33a) to 680 nm (FIG. 33h) in 10 nm increments. For an example of the ratio of Nit power to PFS power for a BR phosphor, where n = 0.25, and thus p = 0.75, the chromaticity points Dom _YAG (x axis) and Duv (y axis) at 3000K ) Is plotted against.

The SPD with the largest LPI (approximately 137) among the 2500 SPDs of 2700K in group 3aDoE is shown in FIG. A specific SPD3400 with a maximum LPI value of about 137 (corresponding to Dom _YAG of about 559 _nm ), Duv of about −0.010, and CCT = 2700K group 3aDoE (YAG + PFS + Nit, where n = 0.25). As shown in FIG. 34, the peak wavelength 3402 of a blue LED of about 450 nm, the peak wavelength 3404 of a YG YAG: Ce phosphor of about 531 nm, the peak wavelength 3406 of an NR PFS phosphor of about 631 nm, and the BR nitride phosphor of about 680 nm. A peak wavelength 3408 is shown; and further compare with Reveal® incandescent lamp SPD 604 and blackbody emitter SPD 602, each with similar CCT.

The target color measurement response, LPI, has a peak wavelength of 631 nm in FIGS. 36a-h for 3000K versus DomYAG (x-axis) and Duv (y-axis) at a chromaticity point of 2700K in FIGS. An NR phosphor having a BR wavelength with a peak wavelength (Peak _Nit ) of 610 nm (FIGS. 35a and 36a) to 680 nm (FIGS. 35h and 36h) in 10 nm increments, and therefore n = 0.5 Plotted for an example ratio of Nit power to PFS power where p = 0.5.

The SPD having the largest LPI (approximately 138) among the 2500 SPDs of 2700K in group 3bDoE is shown in FIG. A specific SPD3700 with a maximum LPI value of about 138 (corresponding to a Dom _YAG of about 559 _nm ), a Duv of about −0.010, and a CCT = 2700K group 3b DoE (YAG + PFS + Nit, where n = 0.50). 37, a peak wavelength 3702 of a blue LED of about 450 nm, a peak wavelength 3704 of a YG YAG: Ce phosphor of about 531 nm, a peak wavelength 3706 of an NR PFS phosphor of about 631 nm, and a BR nitride phosphor of about 680 nm. A peak wavelength 3708 is shown; further, compare SPED 604 for Reveal® incandescent lamps and SPD 602 for blackbody emitters, each with similar CCT.

The target color measurement response, LPI, is the peak wavelength of 631 nm in FIGS. 39a-h for 3000K versus Dom _YAG (x-axis) and Duv (y-axis) at the chromaticity point of 2700K in FIGS. And a BR phosphor having a peak wavelength (Peek _Nit ) of 610 nm (FIGS. 38a and 39a) to 680 nm (FIGS. 38h and 39h) in 10 nm increments, and n = 0.75, Therefore, an example of the ratio of Nit power to PFS power where p = 0.25 is plotted.

The SPD having the largest LPI (about 140) among 2500 SPDs of 2700K in group 3cDoE is shown in FIG. A specific SPD 4000 with a maximum LPI value of about 140 (corresponding to a Dom _YAG of about 559 _nm ), a Duv of about −0.010, and a CCT = 2700K group 3cDoE (YAG + PFS + Nit, where n = 0.75). As shown in FIG. 40, the peak wavelength 4002 of the blue LED of about 450 nm, the peak wavelength 4004 of the YG YAG: Ce phosphor of about 531 nm, the peak wavelength 4006 of the NR PFS phosphor of about 631 nm, and the BR nitride phosphor of about 680 nm. Peak wavelength 4008 is shown; further, compare Reveal® incandescent lamp SPD 604 and black body emitter SPD 602, each with similar CCT.

As shown in FIG. 23, the Dom _YAG and Duv values of 250 unique combinations of 25 different Dom _YAG values for each of the five different Duv values used in Group 1 DoE and Group 2 DoE are 20 different. The same 250 unique combinations of Dom _YAG and Duv used in group 3 DoE in combination with each of the BR phosphors. The fine spacing between the Dom _YAG value on the x-axis and the Duv value on the y-axis of the 250 unique SPDs used in Group 3 DoE can actually lead to smooth interpolation between the individual SPDs used in DoE. It was found. Although five Duv levels have been used herein to describe the effect of chromaticity points or Duv on LPI, other suitable Duv levels may be used. For example, similar contour plots may be presented for a continuum of Duv levels within the Duv range represented herein, and a similar trend is realized. The smooth curves of LPI shown in FIGS. 32, 33, 35, 36, 38 and 39 are obtained by fitting a statistically optimized ANOVA regression to the data, where LPI = f (CCT, Duv , Dom _YAG , Peak _Nit , n), including a polynomial equivalent to the quartic and all the resulting variable interactions, resulting in a transfer function with Adjusted R ² > 0.99. Those skilled in the art will understand that LPI contours with LPI values greater than 120 lack the ability to include higher order equations than quartics and that there is a smooth transition between the indicated contours. In addition, the solution representing all 15000 combinations of SPDs consisting of blue LEDs, YG YAG: Ce phosphors, NR PFS phosphors and BR phosphors is the ratio of red power, n, in FIGS. Quantitatively with very low error (R ² > 0.99) by the transfer function LPI = f (CCT, Duv, Dom _YAG , Peak _Nit , n) represented by LPI contour plots of 35, 36, 38 and 39 Will be understood.

Figures 32, 33, 35, 36, 38 and 39 show that for both 2700K and 3000K, if the chromaticity point of the light source is on the blackbody locus (Duv = 0.000), all Dom _YAG (ie whatever Commercially available YG YAG: Ce phosphor) proves that it is difficult to achieve LPI> 120. Only long wavelength nitrides (Peak _Nit > 660 nm) and short wavelength YAG (Dom _YAG <562 nm) allow LPI> 120 on black bodies. As Duv decreases, LPI usually increases with all Dom _YAG , and Duv reaches a maximum of about -0.010 according to equation (1) (this Duv value maximizes the whiteness component of LPI). A considerable degree of LPI contour symmetry is obtained for the horizontal line of Duv = −0.010. When Duv moves from Duv = 0.000 to Duv = −0.010, the whiteness component of the LPI equation increases from 0 to 1, and the LPI increases by 19 points based on equation (7). Similarly, when Duv moves from Duv = −0.010 to Duv = −0.020, the whiteness component decreases from 1 to 0 and the LPI decreases by 19 points.

For a given Duv and n, LPI, which increases almost monotonically as Dom _YAG decreases and Peak _Nit increases, mainly reduces large yellow emission, or red-green opposition and blue-yellow Creating a dip in the yellow portion of the spectrum (eg, about 570 to about 600 nm) that enhances the perceived saturation of the opposite color of, and may be due to separation between the wavelengths of the YG and BR emitters.

The effect of the ratio of broadband red emission to all red emission or “n” can be seen by comparing different sets of contour plots (ie, FIGS. 32, 33 vs. 35, 36 vs. 38, 39). For short Peak _Nit values (Peak _Nit <660 nm), corresponding to the contour plots a to e in the above figure, when n increases from n = 0.25 to n = 0.50 to n = 0.75, The LPI value achievable with a given Duv and Peak _Nit is reduced. For example, in FIG. 32a (n = 0.25), the maximum achievable LPI (Duv = −0.010 and Dom _YAG = 559) is approximately LPI = 129, whereas FIG. 35a (n = 0.50). And in FIG. 38a (n = 0.75), the LPI for the same Duv and Dom _YAG is about LPI = 123 and about LPI = 116, respectively. For long Peak _Nit values (Peak _Nit > 660 nm), corresponding to the contour plots g and h in the above figure, when n increases from n = 0.25 to n = 0.50 to n = 0.75, The LPI value achievable with a given Duv and Peak _Nit increases. For example, in FIG. 32h (n = 0.25), the maximum achievable LPI (Duv = −0.010 and Dom _YAG = 559) is approximately LPI = 137, whereas FIG. 35h (n = 0.50) And in FIG. 38h (n = 0.75), the LPI for the same Duv and Dom _YAG is about LPI = 138 and about LPI = 140, respectively. This relationship is summarized in FIG. This figure plots the LPI values for all combinations of red emitters including Group 1 and Group 2 with 2700 K, Duv = −0.010, and Dom _YAG = about 559 _nm .

  Similar to the equation (9) for group 1 DoE and equation (10) for group 2 DoE, a general form of elliptic approximation to the LPI curve for group 3 DoE can be generated. However, due to the higher order terms in the part of the LPI curve, the equations show that for all values of LPI = 120 and higher, the exact LPI contours and FIGS. 32, 33, 35, 36, 38 and It may not be possible to provide a match within 1 or 2 points in the LPI with any of the 39 LPI contour ellipse approximations, so the equations are sufficiently accurate to serve as an exact contour substitution , It may not be possible to provide an approximation to an exact LPI contour. Therefore, in group 3DoE, the color preference is quantified by referring to the area inside the given LPI contour in FIGS. 32, 33, 35, 36, 38 and 39.

  In a first exemplary embodiment of a light source, the LED light source 700 may include one or more LEDs 706 and 708 (for convenience, numbering is taken from FIGS. 7a and 7b), each of which is a YG YAG: Ce phosphor. And one or more blue LEDs coated with an NR phosphor. This first exemplary embodiment is referred to as “YAG + PFS”. In one or more embodiments, the portion of blue light generated by the blue LED that is not absorbed by the phosphor material is combined with the light emitted from the phosphor material to provide light that appears nearly white to the human eye. can do. The spectrum of a YAG + PFS light source with improved color preference is obtained by exciting a YAG: Ce phosphor with blue LED peak emission in the range of about 400 nm to about 460 nm, blue emission from the LED, as depicted in FIG. It may consist of a YG peak emission in the range of about 530 nm to about 557 nm and a red peak emission of about 631 nm obtained by excitation of the NR phosphor with blue emission from the LED. The spectrum says that it may contain indentations in the wavelength range between blue LED emission and YG phosphor emission, and in the yellow wavelength range between YG phosphor and NR phosphor. It may differ from the blackbody spectrum in that respect. The light source may have a CCT between about 2700K and about 3200K in this first exemplary embodiment. In one or more embodiments, the light source may have a higher CCT (eg, on the order of about 10,000K or higher) or a lower CCT (eg, on the order of about 1800K or lower). The decrease in emission in the yellow portion of the color spectrum may be due to the separation of the YG and NR phosphor peaks, which may be caused by the relatively narrow peak wavelength of the NR PFS phosphor. . The decrease in emission may be further enhanced in the yellow part of the color spectrum by the relatively short peak wavelength of the YG phosphor compared to a typical YG YAG: Ce phosphor. Spectral depressions in the yellow part (if deep enough) and enhanced red and green emission compared to the blackbody illuminant are typical blue, YG and red fluorescence that do not produce a sufficiently deep depression in the yellow part. Compared with light emitted from the same light source using a combination of bodies, it is possible to provide a light source with improved color preference or color saturation or color contrast generally preferred by human observers.

FIG. 24 shows the SPD plot 2400 of the YAG + PFS type LED light source considered immediately above with CCT = 2700K; and for comparison, a blackbody SPD plot 602 with CCT = 2700K and a reveal with CCT = 2755K. FIG. 6 shows a graph including an SPD plot 604 of a (registered trademark) type incandescent light source. FIG. Curve 2400 is a special SPD that resulted in a maximum LPI of 137 out of 250 combinations of DoD Group 1 (YAG + PFS) SPDs. The blue LED peak wavelength 2402 occurs at approximately 450 nm, the YG phosphor peak wavelength and dominant wavelength 2404 occur at approximately 531 nm and 559 nm, respectively, the NR phosphor peak wavelength 2406 occurs at approximately 631 _nm , and Dom _YAG approximately 559 nm and Duv. Corresponds to position 2210 in FIG. 22a (when CCT = 2700K) at about −0.010 or 2212 (when CCT = 3000K) in FIG. 22b. The SPD plot 2400 represents a light source with CCT = 2700K, CRI = 69 and LPI = 137. The corresponding SPD of 3000K appears to be very similar with similar CRI and LPI values.

  In this first embodiment, approximately 137 LPIs are obtained, so that a human observer would be able to use a light source with an LPI of typically 120 or less when using the YAG + PFS spectrum 2400 than is possible. Saturated colors, improved whiteness and much more favorable color appearance can be perceived.

In the second exemplary embodiment of the light source where the color preference (LPI) of the YAG + PFS light source is slightly lower than in the first embodiment, the peak wavelength and dominant wavelength of the YG YAG: Ce phosphor 2404 in FIG. , Slightly shifted to wavelengths longer than the optimum peak wavelengths and dominant wavelengths of 531 nm and 559 nm of the first embodiment. In this second exemplary embodiment, Dom _YAG may be as long as about 563 nm, while the chromaticity point Duv is close to -0.010 (about -0.008 to about CCT is about 2700K to about 3000K, and the combination of Dom _YAG and Duv satisfies Equation 9d, which illustrates the contour line of LPI = 135 in FIG. 25a, b.

この第２の例示的な実施形態では、約１３５以上のＬＰＩが得られる、そのため人間の観察者は、ＹＡＧ＋ＰＦＳスペクトル２４００を利用した場合に、一般に１２０以下のＬＰＩを有する光源を使用することによって可能であるよりも飽和した色、向上した白色度及びはるかにより好ましいカラーアピアランスを知覚することができ、約１３７のＬＰＩを有する第１の実施形態よりも非常にわずかに低い飽和色、白色度及びカラーアピアランスを知覚することができる。

In this second exemplary embodiment, an LPI of about 135 or more is obtained, so that a human observer can use a light source that generally has an LPI of 120 or less when utilizing the YAG + PFS spectrum 2400. Saturated color, improved whiteness and much more favorable color appearance than can be perceived, and slightly lower saturated color, whiteness and color than the first embodiment with an LPI of about 137 Appearance can be perceived.

Although the color preference (LPI) of the YAG + PFS light source is further reduced than in the first and second embodiments, the YG YAG: Ce fluorescence of FIG. 24 is still used in the third exemplary embodiment of the light source over the prior art. The peak wavelength and dominant wavelength of the body 2404 move to wavelengths longer than the optimum peak wavelengths and dominant wavelengths of 531 nm and 559 nm of the first embodiment. In this third exemplary embodiment, Dom _YAG may be as long as about 572 _nm , while the chromaticity point Duv is between about -0.002 and about -0.016. Yes, CCT is about 2700K to about 3000K, and the combination of Dom _YAG and Duv satisfies Equation 9a, which illustrates the contour line of LPI = 120 in FIGS. 25a and 25b.

この第３の例示的な実施形態では、約１２０以上のＬＰＩが得られる、そのため人間の観察者は、ＹＡＧ＋ＰＦＳスペクトル２４００を利用した場合に、一般に１２０以下のＬＰＩを有する光源を使用することによって可能であるよりも飽和した色、向上した白色度及びより好ましいカラーアピアランスを知覚することができるが、約１３７のＬＰＩを有する第１の実施形態よりも著しく低い飽和色、白色度及びカラーアピアランスを知覚することができる。

In this third exemplary embodiment, an LPI of about 120 or higher is obtained, so that a human observer can use a light source that generally has an LPI of 120 or lower when utilizing the YAG + PFS spectrum 2400. Can perceive a saturated color, improved whiteness and a more favorable color appearance than is, but perceives a significantly lower saturation color, whiteness and color appearance than the first embodiment with an LPI of about 137. can do.

  In a fourth exemplary embodiment of a light source that provides maximum color preference (LPI) for a YAG + Nit light source, the LED light source 700 is each coated with a YG YAG: Ce phosphor and a BR nitride phosphor (YAG + Nit). One or more LEDs 706 and 708 may be included, which may consist of one or more blue LEDs that are generated here, combined with light emitted from the phosphor material, produced by a blue LED that is not absorbed by the phosphor material The blue light portion provides light that appears almost white to the human eye (again, for convenience only, the graphic element numbers are taken from FIGS. 7a and 7b). The spectrum of the YAG + Nit light source with improved color preference is obtained by exciting the YG YAG: Ce phosphor with blue LED peak emission in the range of about 400 nm to about 460 nm and blue emission from the LED, as depicted in FIG. The YG peak emission in the range of about 530 nm to about 557 nm and the red peak emission in the range of about 610 nm to about 680 nm obtained by excitation of the BR nitride phosphor with blue emission from the LED. The spectrum says that it may contain indentations in the wavelength range between blue LED emission and YG phosphor emission, and in the yellow wavelength range between YG phosphor and BR phosphor. It may differ from the blackbody spectrum in that respect. The light source can have a CCT between about 2700K and about 3200K. In one or more embodiments, the light source may have a higher CCT (eg, on the order of about 10,000K or higher) or a lower CCT (eg, on the order of about 1800K or lower). The decrease in light emission in the yellow part of the color spectrum can result from the separation of the peaks of the YG and BR phosphors, which can be caused mainly by the relatively long peak wavelength of the BR nitride phosphor. . The decrease in emission in the yellow portion of the color spectrum may be further enhanced by the relatively short peak wavelength of the YG phosphor compared to a typical YG YAG: Ce phosphor. The yellow spectral depression (if deep enough) and the enhanced red and green emission compared to the blackbody phosphor are typical of blue, YG and red phosphors that do not produce a sufficiently deep depression in yellow. Compared to light emitted from the same light source using a combination, a light source with improved color preference or color saturation or color contrast that may be preferred by a human observer can be provided.

FIG. 29 shows a graph including a SPD plot 2900 of a YAG + Nit type LED light source with CCT = 2700K; and, for comparison, FIG. 29 also shows a blackbody SPD plot 602 with CCT = 2700K and Also shown is the SPD plot 604 of a Reveal® type incandescent light source with CCT = 2755K. Plot 2900 is a special SPD that yielded a maximum LPI of 142 out of 5000 combinations of DoP Group 2 (YAG + Nit) SPDs. The blue LED peak wavelength 2902 occurs at approximately 450 nm, the YG phosphor peak wavelength and dominant wavelength 2904 occur at approximately 531 nm and 559 nm, respectively, the BR phosphor peak wavelength 2906 occurs at approximately 680 nm, and Dom _YAG approximately 559 nm and Duv. Corresponds to position 2710 in FIG. 27h (when CCT = 2700K) at about −0.010 or 2810 in FIG. 28h (when CCT = 3000K). The SPD plot 2900 represents a light source with CCT = 2700K, CRI = 57 and LPI = 142. The corresponding SPD of 3000K appears to be very similar with similar CRI and LPI values. The LPI score of 142 is very high (in one or more embodiments, the maximum possible LPI is about 150), and when a human observer utilizes a YAG + PFS spectrum 2900, a light source that generally has an LPI of 120 or less. It means that saturated colors, improved whiteness and much more favorable color appearance can be perceived than is possible by using.

  In this fourth embodiment, approximately 142 LPIs are obtained, so that a human observer can use a YAG + Nit spectrum 2900 than is possible by using a light source that generally has an LPI of 120 or less. Saturated colors, improved whiteness and much more favorable color appearance can be perceived.

In the fifth exemplary embodiment of the light source, in which the color preference (LPI) of the YAG + Nit light source is slightly lower than in the fourth embodiment, the peak wavelength and dominant wavelength of the YG YAG: Ce phosphor in FIG. 2904 slightly moves to wavelengths longer than the optimum peak wavelength and the dominant wavelength of 531 nm and 559 nm of the fourth embodiment, and the peak wavelength 2906 of the nitride red phosphor in FIG. 29 is the fourth embodiment. The wavelength is shorter than the optimum peak wavelength of 680 nm. In a fifth exemplary embodiment, Dom _YAG may be as long as about 568 nm and Peak _Nit may be as short as about 660 nm, while Duv of the chromaticity point. Remains close to -0.010 (between about -0.005 and about -0.014), the CCT is about 2700K to about 3000K, and the combination of Dom _YAG and Duv is LPI = 135 in Table 3. Equation 10 is satisfied using the coefficients of

この式を、図３０ｃ〜ｅ及び３１ｃ〜ｅのＬＰＩ＝１３５の等高線を説明する表３のＬＰＩ＝１３５の列の係数で評価する。

This equation is evaluated with the coefficients of the LPI = 135 column of Table 3 illustrating the LPI = 135 contours of FIGS. 30c-e and 31c-e.

この実施形態では、約１３５以上のＬＰＩが得られる、そのため人間の観察者は、ＹＡＧ＋Ｎｉｔスペクトル２９００を利用した場合に、一般に１２０以下のＬＰＩを有する光源を使用することによって可能であるよりも飽和した色、向上した白色度及びはるかにより好ましいカラーアピアランスを知覚することができ、約１４２のＬＰＩを有する第４の実施形態よりも非常にわずかに低い飽和色、白色度及びカラーアピアランスを知覚することができる。

In this embodiment, an LPI of about 135 or more is obtained, so that a human observer is more saturated than would be possible by using a light source with an LPI of typically 120 or less when utilizing the YAG + Nit spectrum 2900. Can perceive color, improved whiteness, and much more favorable color appearance, and can perceive very slightly lower saturated color, whiteness, and color appearance than the fourth embodiment with an LPI of about 142 it can.

In the sixth exemplary embodiment of the light source, the color preference (LPI) of the YAG + Nit light source is further reduced than in the fourth or fifth embodiment, but still exceeds the prior art, YG YAG in FIG. 29: The peak wavelength and dominant wavelength 2904 of the Ce phosphor slightly shift to wavelengths longer than the optimum peak wavelengths and dominant wavelengths of 531 nm and 559 nm of the fourth embodiment, and the peak of the nitride red phosphor in FIG. The wavelength 2906 has moved to a wavelength shorter than the optimum peak wavelength of 680 nm of the fourth embodiment. In a sixth embodiment, Dom _YAG may be as long as about 573 nm, and Peak _Nit may be as short as about 630 nm or 640 nm, while the chromaticity point Duv is Ideally close to -0.010, but can be anywhere in the range of about 0.000 to about -0.019, CCT is about 2700K to about 3000K, and a combination of Dom _YAG and Duv Satisfies Equation 10 using the coefficients in the LPI = 120 column of Table 3.

この式を、図３０ａ〜ｅ及び３１ａ〜ｅのＬＰＩ＝１２０の等高線を説明する表３のＬＰＩ＝１２０の列の係数で評価する。

This equation is evaluated with the coefficients of the LPI = 120 column of Table 3 illustrating the LPI = 120 contours of FIGS. 30a-e and 31a-e.

この第６の例示的な実施形態では、約１２０のＬＰＩが得られる、それは人間の観察者が、ＹＡＧ＋Ｎｉｔスペクトル２９００を利用した場合に、一般に１２０以下のＬＰＩを有する光源を使用することによって可能であるよりも飽和した色、向上した白色度及びより好ましいカラーアピアランスを知覚することを意味する。

In this sixth exemplary embodiment, approximately 120 LPIs are obtained, which is possible by using a light source that generally has an LPI of 120 or less when a human observer utilizes the YAG + Nit spectrum 2900. It means perceiving a saturated color, improved whiteness and a more favorable color appearance than some.

  In a seventh exemplary embodiment of a light source that provides maximum color preference (LPI) for a YAG + PFS + Nit light source, the LED light source may include one or more LED groups, each of which is a YG YAG: Ce phosphor. And one or more blue LEDs coated with a combination of NR PFS phosphor and BR nitride phosphor (YAG + PFS + Nit). The portion of the blue light generated by the blue LED that is not absorbed by the phosphor material, here combined with the light emitted from the phosphor material, can provide light that appears nearly white to the human eye. The spectrum of the YAG + PFS + Nit light source with improved color preference is shown in FIGS. 34, 37 and 40, with the blue LED peak emission in the range of about 400 nm to about 460 nm, the YAG: Ce phosphor due to the blue emission from the LED. YG peak emission in the range of about 530 nm to about 557 nm obtained by excitation, about 631 nm red peak emission obtained by excitation of NR PFS phosphor with blue emission from blue LED and BR nitride with blue emission from blue LED It may consist of an additional red emission having a peak in the range of about 610 nm to about 680 nm obtained by excitation of the phosphor. The spectra shown in FIGS. 34, 37 and 40 may include a depression in the wavelength region between the blue LED emission and the YG phosphor emission, which is the yellow color between the YG phosphor and the red phosphor. It may be different from the blackbody spectrum in that it may contain indentations in the wavelength range. The light source can have a CCT between about 2700K and about 3200K. In one or more embodiments, the light source may have a higher CCT (eg, on the order of about 10,000K or higher) or a lower CCT (eg, on the order of about 1800K or lower). The decrease in emission of the color spectrum of the yellow part (indicated by the indentation in the yellow wavelength region between the YG phosphor and the red phosphor) is due to the relatively narrow peak wavelength and BR nitride of the NR PFS phosphor. It may be due to the separation of the YG and red phosphor peaks that may be caused by the relatively long peak wavelength of the phosphor. The decrease in emission of the yellow part may be further enhanced by the relatively short peak wavelength of the YG phosphor compared to typical YG YAG: Ce phosphors. Spectral depressions in the yellow part (if sufficiently deep) and enhanced emission in the red and green parts compared to blackbody phosphors are typical blue, YG and red phosphors that do not produce a sufficiently deep depression in yellow. Providing a light source with improved color preference or color saturation or color contrast that may be generally preferred by a human observer compared to light emitted from the same light source using a combination of it can.

Dividing DoE into three groups is a matter of convenience for conveying the results. In practice, the ratio BR / R = n can have a continuous range of 0.0 to 1.0, and the limited examples of n = 0 and n = 1 are first to third and fourth. Corresponding to the group 1 (YAG + PFS) and group 2 (YAG + Nit) portions of DoE respectively represented by the sixth to sixth embodiments. Group 3 DoE is represented herein as having three separate levels of n = 0.25, 0.50, and 0.75, but when the responses of groups 1 and 2 are combined with group 3, the value of. It yields the transfer function of all consecutive ranges of LPI with 0 ≦ n ≦ 1.0. The seventh to ninth embodiments (some of which are described below) are all continuous ranges of 0.0 ≦ n ≦ 1.0 other than n = 0 or n = 1, ie 0.0 <N <1.0 can represent any combination of Nit and PFS red phosphors described herein. The maximum LPI in the first embodiment (n = 0.0) is 137, and in the fourth embodiment (n = 1.0) is 142, which corresponds to Dom _YAG = 559 nm and Peak _Nit = 680 nm. To do. As described herein, the maximum LPI using any combination of PFS and Nit (0.0 <n <1.0) is seen to occur from DoE to Dom _YAG = 559 nm and Peak _Nit = 680 nm. Near n = 1 (ie, mostly Nit, with a small amount of PFS) and may occur with about 142 LPIs. In one or more embodiments, the maximum LPI for any value of 0 <n <1 per DoE occurs at Dom _YAG = 559 nm and Peak _Nit = 680 nm. We believe that this is because the maximum separation of the red nitride peak from the YG YAG peak exceeds the separation between the PFS red peak and the YG YAG peak, so that the red nitride phosphor emission at 680 nm is PFS fluorescence. Particular mention is made that there may be potentially greater color contrast and higher color preference than body luminescence, but there are severe penalties in terms of efficiency. It is found that the LPI decreases monotonically with decreasing n (more PFS) to a value of 137 at Do = 0 for Dom _YAG = 559 nm and Peak _Nit = 680 nm in DoE.

34, 37, and 40 include SPD curves 3400, 3700, and 4000 of SPDs of YAG + PFS + Nit type LED light sources with n being 0.25, 0.50, and 0.75, respectively, and CCT = 2700K. For comparison, FIGS. 34, 37 and 40 also include a blackbody SPD plot 602 with CCT = 2700K and a SPED plot 604 of a Reveal® incandescent light source with CCT = 2755K. Curves 3400, 3700, and 4000 are 137, 138, and 140 for n = 0.25, 0.50, and 0.75, respectively, out of 5000 combinations of SPDs in DoE groups 3a, b, and c, respectively. A special SPD that yielded the maximum LPI. Blue LED peak wavelengths 3402, 3702 and 4002 occur at approximately 450 nm, YG phosphor peak wavelengths and calculated dominant wavelengths 3404, 3704 and 4004 occur at approximately 531 nm and 559 nm, respectively, and NR phosphor peak wavelengths 3406, 3706 and 4006 occur at approximately 631 nm, and the BR phosphor peak wavelengths 3408, 3708 and 4008 occur at approximately 680 nm, with a Dom _YAG of approximately 559 _nm and a Duv of approximately −0.010, respectively, in positions 32 h, 35 h and 38 h. 3210, 3510 and 3810 (when CCT = 2700K) or 3310, 3610 and 3910 (when CCT = 3000K) in FIGS. 33h, 36h and 39h, respectively. SPDs 3400, 3700 and 4000 represent light sources with CRI = 68, 67, 65 and LPI = 137, 138 and 140 for CCT = 2700K, n = 0.25, 0.50 and 0.75, respectively. In one or more embodiments, a 3000K corresponding SPD may be very similar with similar CRI and LPI values. Since the LPI scores of 137, 138 and 140 are high for n = 0.25, 0.50 and 0.75 respectively (in one or more embodiments, the maximum possible LPI is about 150), Perceiving saturated color, improved whiteness and much more favorable color appearance when using YAG + PFS spectra 3400, 3700, and 4000, typically using light sources with LPI of 120 or less Can do.

  In this seventh embodiment, an LPI of about 140-142 is obtained, so that a human observer can use a light source that typically has an LPI of 120 when utilizing YAG + PFS + Nit spectra 3400, 3700 and 4000. Saturated colors, improved whiteness and much more favorable color appearance can be perceived than is possible.

In the eighth exemplary light source embodiment of the light source, with a slightly lower YAG + Nit light source color preference (LPI) than in the seventh embodiment, the YG YAG: Ce phosphor in FIGS. 34, 37 and 40 The peak wavelengths and main wavelengths 3404, 3704 and 4004 of FIG. 34 are slightly shifted to wavelengths longer than the optimum peak wavelengths and main wavelengths of 531 nm and 559 nm of the seventh embodiment, and the nitrides in FIGS. The peak wavelengths of the red phosphors 3408, 3708, and 4008 are shifted to wavelengths shorter than the optimum peak wavelength of 680 nm in the seventh embodiment. In the eighth embodiment, Dom _YAG may be as long as about 566 nm and Peak _Nit may be as short as about 660 nm, but the chromaticity point Duv is −0. Staying close to 010 (between about -0.008 and about -0.012), the CCT is about 2700K to about 3000K. In this embodiment, an LPI of about 135 or more is obtained, so that a human observer is possible by using a light source that typically has an LPI of 120 or less when utilizing YAG + PFS + Nit spectra 3400, 3700 and 4000. More saturated color, improved whiteness and a much more favorable color appearance, with a slightly slightly lower saturation color, whiteness and color appearance than the seventh embodiment having an LPI of about 142 Can perceive.

In the ninth exemplary embodiment of the light source, the color preference (LPI) of the YAG + PFS + Nit light source is further reduced than that of the seventh embodiment, but still generally surpasses a light source having an LPI of 120 or higher. And 40 calculated YG YAG: Ce phosphor peak wavelengths and calculated principal wavelengths 3404, 3704 and 4004 slightly shift to wavelengths longer than the optimal peak wavelengths and dominant wavelengths of 531 nm and 559 nm of the seventh embodiment. However, the peak wavelengths 3408, 3708 and 4008 of the nitride red phosphor in FIGS. 34, 37 and 40 are shifted to wavelengths shorter than the optimum peak wavelength of 680 nm in the seventh embodiment. In the ninth embodiment, Dom _YAG may be as long as about 572 nm and Peak _Nit may be as short as about 620 nm, but the chromaticity point Duv is ideally Near -0.010, but can be anywhere within the range of about 0.000 to about -0.018, with a CCT of about 2700K to about 3000K. In this embodiment, an LPI of about 120 or more is obtained, so that a human observer is possible by using a light source that generally has an LPI of 120 or less when utilizing YAG + PFS + Nit spectra 3400, 3700 and 4000. More saturated colors, improved whiteness and more favorable color appearance can be perceived.

  Further, in some embodiments, a yellow absorbing filter, such as neodymium (Nd) glass or Nd compound or equivalent yellow filter, can be incorporated into the light source, such as a neodymium (Nd) glass dome, for an LED light engine. The Nd glass dome can serve to suppress yellow light and further enhance the perception of red and green vividness. While the above embodiment demonstrates the ability to achieve high LPI without the use of a yellow filter, such use is not possible with other LPI values that cannot achieve high LPI without absorption by Nd. Allows selection of available phosphor materials. Thereby, for example, the peak wavelength of the red phosphor can be moved to a shorter wavelength, or the FWHM of the red phosphor can be increased. Alternatively, the inclusion of a yellow filter can result in a further enhanced color preference (higher LPI) by further strengthening the yellow indentation.

  The above description and / or the accompanying drawings do not imply a fixed order or sequence of any process steps mentioned in this specification, but rather are performed in any order in which any process can be performed. It will be understood that this includes, but is not limited to, the simultaneous implementation of the steps shown as being continuous.

  Although the invention has been described with reference to specific exemplary embodiments, various changes, substitutions, and alterations apparent to those skilled in the art may be made without departing from the spirit and scope of the invention as set forth in the appended claims. It will be appreciated that the disclosed embodiments may be practiced.

Claims (98)

A synthetic light source,
One or more blue light sources having a peak wavelength in the range of about 400 nm to about 460 nm;
One or more yellow-green garnet phosphors;
A synthetic light source comprising one or more narrowband red downconverters, wherein the synthetic light source has an illumination preference index (LPI) of 120 or more.   The synthetic light source according to claim 1, wherein LPI is 125 or more.   The synthetic light source according to claim 1, wherein LPI is 130 or more.   The synthetic light source according to claim 1, wherein LPI is 135 or more.   The synthetic light source according to claim 1, wherein LPI is 140 or more.   The synthetic light source of claim 1, wherein the one or more narrow-band red downconverter light sources have a peak wavelength in the range of about 610 nm to about 660 nm.   The synthetic light source of claim 1, wherein the one or more blue light sources comprise a solid state light source.   The synthetic light source of claim 7, wherein the one or more blue light sources comprises at least one of a semiconductor light emitting diode (LED) light source, an organic light emitting diode (OLED) light source, and a polymer light emitting diode light source.   The synthetic light source of claim 1, wherein the one or more yellow-green garnet phosphors have a dominant wavelength in the range of about 559 nm to about 574 nm.   The synthetic light source of claim 1, wherein the one or more yellow-green garnet phosphors have a full width at half maximum (FWHM) of about 110 nm to about 115 nm.   The synthetic light source according to claim 1, wherein the one or more yellow-green garnet phosphors are YAG: Ce phosphors.   The synthetic light source of claim 1, wherein the one or more narrowband red downconverters include at least one of a phosphor downconverter and a quantum dot downconverter.   The synthetic light source of claim 12, wherein the narrowband red downconverter is manganese-doped potassium fluorosilicate (PFS).   The narrowband red downconverter is PFS, the YAG: Ce phosphor has a dominant wavelength in the range of about 559 nm to about 572 nm, and Duv is in the range of about -0.002 to -0.016. Item 12. The synthetic light source according to Item 11.   The narrowband red downconverter is PFS, the YAG: Ce phosphor has a dominant wavelength in the range of about 559 nm to about 563 nm, and Duv is in the range of about -0.008 to -0.012. Item 12. The synthetic light source according to Item 11.   The synthetic light source of claim 11, wherein the narrowband red downconverter is PFS, the YAG: Ce phosphor has a dominant wavelength of about 559 nm, and Duv is about -0.010.   The combined light source emits a color spectrum including a blue wavelength range emitted from a blue light source, a yellow wavelength range emitted from a yellow-green garnet phosphor and a red wavelength range emitted from a narrowband red downconverter; The synthetic light source according to claim 1, wherein the color spectrum includes a depression in the yellow wavelength region compared to the black body spectrum, and the depression in the yellow wavelength region is about 570 nm to 600 nm.   The synthetic light source of claim 1, wherein the synthetic light source has a correlated color temperature (CCT) in the range of about 2500 Kelvin (K) to about 3200K.   Most or all of the light emitted from the combined light source passes through a neodymium filter, one or more yellow-green garnet phosphors and one or more narrow-band red downconverters superimposed on one or more blue light sources. The synthetic light source of claim 1 further comprising: A synthetic light source,
One or more blue light sources having a peak wavelength in the range of about 400 nm to about 460 nm;
One or more YAG: Ce phosphors;
A synthetic light source, comprising one or more narrowband red downconverters, wherein the color appearance of the synthetic light source is represented as follows:

In the formula, Duv is a unit of measurement of whiteness of the synthetic light source, and Dom _YAG is the main wavelength of one or more YAG: Ce phosphors. 21. The synthetic light source of claim 20, wherein the color appearance of the synthetic light source is represented as follows:

21. The synthetic light source of claim 20, wherein the color appearance of the synthetic light source is represented as follows:

21. The synthetic light source of claim 20, wherein the color appearance of the synthetic light source is represented as follows:

  21. The synthetic light source of claim 20, wherein the one or more narrow band red downconverter light sources have a peak wavelength in the range of about 610 nm to about 660 nm.   21. The synthetic light source of claim 20, wherein the one or more blue light sources comprises a solid light source.   26. The synthetic light source of claim 25, wherein the one or more blue light sources comprises at least one of a semiconductor light emitting diode (LED) light source, an organic light emitting diode (OLED) light source, and a polymer light emitting diode light source.   The synthetic light source according to claim 20, further comprising at least one yellow-green garnet phosphor different from the YAG: Ce phosphor.   21. The synthetic light source of claim 20, wherein the one or more YAG: Ce phosphors have a dominant wavelength in the range of about 559 nm to about 574 nm.   21. The synthetic light source of claim 20, wherein the one or more YAG: Ce phosphors have a full width at half maximum (FWHM) of about 110 nm to about 115 nm.   21. The synthetic light source of claim 20, wherein the one or more narrowband red downconverters include at least one of a phosphor downconverter and a quantum dot downconverter.   31. The synthetic light source of claim 30, wherein the narrowband red downconverter is manganese-doped potassium fluorosilicate (PFS).   32. The synthetic light source of claim 31, wherein the YAG: Ce phosphor has a dominant wavelength in the range of about 559 nm to about 572 nm, and Duv is in the range of about -0.002 to -0.016.   32. The synthetic light source of claim 31, wherein the YAG: Ce phosphor has a dominant wavelength in the range of about 559 nm to about 563 nm and Duv is in the range of about -0.008 to about -0.012. .   32. The synthetic light source of claim 31, wherein the YAG: Ce phosphor has a dominant wavelength of about 559 nm and Duv is about -0.010.   A combined light source emits a color spectrum including a blue wavelength range portion emitted from a blue light source, a yellow wavelength range portion emitted from a YAG: Ce phosphor, and a red wavelength range portion emitted from a narrowband red downconverter; 21. The synthetic light source of claim 20, wherein the color spectrum includes a depression in the yellow wavelength region compared to the black body spectrum, and the depression in the yellow wavelength region is about 570 nm to 600 nm.   21. The synthetic light source of claim 20, wherein the synthetic light source has a correlated color temperature (CCT) in the range of about 2500 Kelvin (K) to about 3200K.   Most or all of the light emitted from the combined light source passes through a neodymium filter superimposed on one or more blue light sources, one or more YAG: Ce phosphors and one or more narrow-band red downconverters. 21. The synthetic light source of claim 20, further comprising: A synthetic light source,
One or more blue light sources having a peak wavelength in the range of about 400 nm to about 460 nm;
One or more yellow-green garnet phosphors;
A synthetic light source comprising one or more broadband red downconverters, wherein the synthetic light source has an illumination preference index (LPI) of 120 or more.   The synthetic light source according to claim 38, wherein LPI is 125 or more.   The synthetic light source according to claim 38, wherein LPI is 130 or more.   The synthetic light source according to claim 38, wherein LPI is 135 or more.   The synthetic light source according to claim 38, wherein LPI is 140 or more. 40. The synthetic light source of claim 38, wherein the one or more broadband red downconverter light sources have a peak wavelength in the range of about 610 nm to about 680 nm.   40. The synthetic light source of claim 38, wherein the one or more blue light sources comprises a solid state light source.   45. The synthetic light source of claim 44, wherein the one or more blue light sources comprises at least one of a semiconductor light emitting diode (LED) light source, an organic light emitting diode (OLED) light source, and a polymer light emitting diode light source.   40. The synthetic light source of claim 38, wherein the one or more yellow-green garnet phosphors have a dominant wavelength in the range of about 559 nm to about 574 nm.   40. The synthetic light source of claim 38, wherein the one or more yellow-green garnet phosphors have a full width at half maximum (FWHM) of about 110 nm to about 115 nm.   40. The synthetic light source of claim 38, wherein the one or more yellow-green garnet phosphors are YAG: Ce phosphors. 40. The synthetic light source of claim 38, wherein the one or more broadband red downconverters include at least one of a phosphor downconverter and a quantum dot downconverter.   50. The synthetic light source of claim 49, wherein the broadband red downconverter is a broadband red nitride phosphor. The synthetic light source according to claim 50, wherein the broadband red nitride phosphor is represented by a general formula CaAlSiN ₃ : Eu ²⁺ .   The broadband red downconverter is a broadband red nitride having a peak wavelength in the range of about 630 nm to about 680 nm, the YAG: Ce phosphor has a dominant wavelength in the range of about 559 nm to about 573 nm, and the Duv is about 49. The synthetic light source of claim 48, which is in the range of 0.000 to about -0.019.   The broadband red downconverter is a broadband red nitride having a peak wavelength in the range of about 660 nm to about 680 nm, the YAG: Ce phosphor has a dominant wavelength in the range of about 559 nm to about 568 nm, and the Duv is about 49. The synthetic light source of claim 48, which is in the range of -0.005 to about -0.014.   49. The broadband red downconverter is a broadband red nitride having a peak wavelength of about 680 nm, the YAG: Ce phosphor has a dominant wavelength of about 559 nm, and Duv is about -0.010. Synthetic light source.   A combined light source emits a color spectrum that includes a blue wavelength range emitted from a blue light source, a yellow wavelength range emitted from a yellow-green garnet phosphor, and a red wavelength range emitted from a broadband red downconverter. 39. The synthetic light source of claim 38, wherein the spectrum includes a depression in the yellow wavelength region portion as compared to the black body spectrum, and the depression in the yellow wavelength region portion is between about 570 nm and 600 nm.   40. The synthetic light source of claim 38, wherein the synthetic light source has a correlated color temperature (CCT) in the range of about 2500 Kelvin (K) to about 3200K.   Most or all of the light emitted from the combined light source passes through a neodymium filter, one or more yellow-green garnet phosphors and one or more broadband red downconverters superimposed on one or more blue light sources. The synthetic light source according to claim 38, further comprising: A synthetic light source,
One or more blue light sources having a peak wavelength in the range of about 400 nm to about 460 nm;
One or more YAG: Ce phosphors;
A synthetic light source comprising one or more broadband red nitride phosphors, wherein the color appearance of the synthetic light source is represented as follows:

Where Duv is the unit of measurement of the whiteness of the synthetic light source, Peak _Nit is the peak wavelength of one or more broadband red nitride phosphors, and Dom _YAG is the main of one or more YAG: Ce phosphors. Is the wavelength. 59. The synthetic light source of claim 58, wherein the color appearance of the synthetic light source is represented as follows:

59. The synthetic light source of claim 58, wherein the color appearance of the synthetic light source is represented as follows:

59. The synthetic light source of claim 58, wherein the color appearance of the synthetic light source is represented as follows:

59. The synthetic light source of claim 58, wherein the color appearance of the synthetic light source is represented as follows:

  59. The synthetic light source of claim 58, wherein the one or more broadband red nitride phosphors have a peak wavelength in the range of about 610 nm to about 680 nm.   59. The synthetic light source of claim 58, wherein the one or more blue light sources comprises a solid state light source.   The synthetic light source of claim 64, wherein the one or more blue light sources comprises at least one of a semiconductor light emitting diode (LED) light source, an organic light emitting diode (OLED) light source, and a polymer light emitting diode light source.   59. The synthetic light source of claim 58, further comprising one or more yellow-green garnet phosphors different from YAG: Ce phosphors.   59. The synthetic light source of claim 58, wherein the one or more YAG: Ce phosphors have a dominant wavelength in the range of about 559 nm to about 574 nm. 59. The synthetic light source of claim 58, wherein the one or more YAG: Ce phosphors have a full width at half maximum (FWHM) of about 110 nm to about 115 nm. Broadband red nitride phosphor has the general formula CaAlSiN _3: represented by Eu ^2+, synthetic light source according to claim 58.   The broadband red nitride phosphor has a peak wavelength in the range of about 630 nm to about 680 nm, the YAG: Ce phosphor has a dominant wavelength in the range of about 559 nm to about 573 nm, and the Duv is about 0.000 to about 59. The synthetic light source of claim 58, which is in the range of about -0.019.   The broadband red nitride phosphor has a peak wavelength in the range of about 660 nm to about 680 nm, the YAG: Ce phosphor has a dominant wavelength in the range of about 559 nm to about 568 nm, and the Duv is about −0.005. 59. The synthetic light source of claim 58, which is in the range of about -0.014.   59. The synthetic light source of claim 58, wherein the broadband red nitride phosphor has a peak wavelength of about 680 nm, the YAG: Ce phosphor has a dominant wavelength of about 559 nm, and Duv is about -0.010.   The combined light source emits a color spectrum that includes a blue wavelength region emitted from a blue light source, a yellow wavelength region emitted from a YAG: Ce phosphor, and a red wavelength region emitted from a broadband red nitride phosphor. 59. The synthetic light source of claim 58, wherein the color spectrum includes a depression in the yellow wavelength region portion as compared to the black body spectrum, and the depression in the yellow wavelength region portion is between about 570 nm and 600 nm.   59. The synthetic light source of claim 58, wherein the synthetic light source has a correlated color temperature (CCT) in the range of about 2500 Kelvin (K) to about 3200K.   And further comprising a neodymium filter overlying one or more blue light sources, one or more YAG: Ce phosphors and one or more broadband red nitride phosphors, wherein most or all of the light emitted from the synthetic light source is 59. The synthetic light source of claim 58 that passes through a filter. A synthetic light source,
One or more blue light sources having a peak wavelength in the range of about 400 nm to about 460 nm;
One or more yellow-green garnet phosphors;
One or more narrowband red downconverters;
A synthetic light source comprising one or more broadband red downconverters, wherein the synthetic light source has an illumination preference index (LPI) of 120 or more.   The synthetic light source according to claim 76, wherein LPI is 125 or more.   The synthetic light source according to claim 76, wherein LPI is 130 or more.   The synthetic light source according to claim 76, wherein LPI is 135 or more.   The synthetic light source according to claim 76, wherein LPI is 140 or more.   77. The synthetic light source of claim 76, wherein the one or more narrowband red downconverter light sources have a peak wavelength in the range of about 610 nm to about 660 nm. 77. The synthetic light source of claim 76, wherein the one or more broadband red downconverter light sources have a peak wavelength in the range of about 610 nm to about 680 nm.   77. The synthetic light source of claim 76, wherein the one or more blue light sources comprises a solid state light source.   84. The synthetic light source of claim 83, wherein the one or more blue light sources comprises at least one of a semiconductor light emitting diode (LED) light source, an organic light emitting diode (OLED) light source, and a polymer light emitting diode light source.   77. The synthetic light source of claim 76, wherein the one or more yellow-green garnet phosphors have a dominant wavelength in the range of about 559 nm to about 574 nm.   77. The synthetic light source of claim 76, wherein the one or more yellow-green garnet phosphors have a full width at half maximum (FWHM) of about 110 nm to about 115 nm.   77. The synthetic light source of claim 76, wherein the one or more yellow-green garnet phosphors are YAG: Ce phosphors.   77. The synthetic light source of claim 76, wherein the one or more narrowband red downconverters include at least one of a phosphor downconverter and a quantum dot downconverter.   90. The synthetic light source of claim 88, wherein the narrowband red downconverter is PFS. 77. The synthetic light source of claim 76, wherein the one or more broadband red downconverters include at least one of a phosphor downconverter and a quantum dot downconverter.   The synthetic light source of claim 90, wherein the broadband red downconverter is a broadband red nitride phosphor. Broadband red nitride phosphor has the general formula CaAlSiN _3: represented by Eu ^2+, synthetic light source according to claim 91.   The narrowband red downconverter is PFS, the broadband red downconverter is a broadband red nitride phosphor having a peak wavelength in the range of about 620 nm to about 680 nm, and the YAG: Ce phosphor is in the range of about 559 nm to about 572 nm. 88. The synthetic light source of claim 87, wherein the combined light source has a dominant wavelength within and a Duv in the range of about 0.000 to -0.018.   The narrowband red downconverter is PFS, the broadband red downconverter is a broadband red nitride phosphor having a peak wavelength in the range of about 660 nm to about 680 nm, and the YAG: Ce phosphor is in the range of about 559 nm to about 566 nm. 88. The synthetic light source of claim 87, wherein the combined light source has a dominant wavelength within and a Duv is in the range of about -0.008 to about -0.012.   The narrowband red downconverter is PFS, the broadband red downconverter is a broadband red nitride phosphor having a peak wavelength of about 680 nm, the YAG: Ce phosphor has a dominant wavelength of about 559 nm, and the Duv is about 88. The synthetic light source of claim 87, which is -0.010.   The combined light source includes a blue wavelength range emitted from a blue light source, a yellow wavelength range emitted from a yellow-green garnet phosphor, and a red wavelength range emitted from a narrowband red downconverter and a broadband red downconverter. 77. The synthetic light source of claim 76, wherein the synthetic light source emits a spectrum and the color spectrum includes a depression in the yellow wavelength region compared to the black body spectrum, and the depression in the yellow wavelength region is about 570 nm to 600 nm.   77. The synthetic light source of claim 76, wherein the synthetic light source has a correlated color temperature (CCT) in the range of about 2500 Kelvin (K) to about 3200K.   A neodymium filter, one or more yellow-green garnet phosphors, one or more narrow-band red downconverters and one or more broadband red downconverters superimposed on one or more blue light sources 77. The synthetic light source of claim 76, further comprising such that most or all passes through the filter.

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