JP7125618B2 - light emitting device - Google Patents

Description

The present invention relates to light emitting devices.

As a light-emitting device using a light-emitting element such as a light-emitting diode (hereinafter abbreviated as "LED"), a light-emitting element that emits blue light and a light-emitting element that emits yellowish light when excited by the light from the light-emitting element are used. 2. Description of the Related Art A light-emitting device that emits mixed white light using phosphors is known. Such light-emitting devices are used in a wide range of fields such as general lighting, vehicle-mounted lighting, displays, and backlights for liquid crystals.

By the way, it has been reported that the probability of developing sleep disorders and depression tends to be higher in areas with high latitudes and relatively little sunlight (for example, Northern Europe and North America outside of Japan, and the Tohoku region in Japan). ing.

Disruption of circadian rhythm is considered to be one of the factors that increase the probability of developing sleep disorders and depression in areas with little sunlight. Circadian is a coined word combining "Circa" which means "about" in Latin and "Dies" which means "one day", and means "circadian rhythm". The reason why humans wake up and feel sleepy in a 1-day cycle is that the biological clock in the body is working rather than the influence of external environmental factors due to changes in the brightness or darkness of the outside world. The human sleep and body temperature rhythm cycle is about 25 hours, which is slightly longer than one day, but in normal life, changes in the external environment act as stimuli, and the body clock is synchronized by correcting the phase. Organisms use light as a tuning factor. Humans with a 25-hour cycle synchronize by advancing the phase with light exposed in the morning, and mice with a 23-hour cycle shift the phase with light exposed before sunset. Synchronize by retreating. In other words, light-triggered control of the biological clock is extremely important in forming the circadian rhythm.

In 2002, a new photoreceptor other than rods and cones was discovered on the retina of mammals, and was named intrinsically photosensitive retinal ganglion cell (ipRGC). there is It has been clarified that ipRGC has a visual substance called melanopsin and is involved in non-visual functions such as light entrainment of circadian rhythm and pupillary reflex. ipRGCs are cells that give light signals by direct administration to the suprachiasmatic nucleus. The suprachiasmatic nucleus is a very small area in the hypothalamus of the brain that plays the role of the biological clock that governs the circadian rhythm of mammals. It creates circadian rhythms of various physiological functions such as hormone secretion. In other words, control of the endogenous photoresponse of ipRGC is very important in forming circadian rhythms.

Melanopsin possessed by ipRGC expresses a photoreceptor protein in 1% to 2% of retinal ganglion cells. Most other retinal ganglion cells are not light sensitive. It is known that the photoreceptors have different absorption characteristics depending on the cell, and melanopsin has a peak wavelength in the vicinity of 480 nm to 490 nm. Opsins possessed by cones have peak wavelengths around 440 nm for S cones, around 535 nm for M cones, around 565 nm for L cones, and around 507 nm for rhodopsin possessed by rods.

Melanopsin is also believed to be involved in the secretion or suppression of melatonin, a sleep-promoting hormone. Melatonin shows a secretion peak at night, and the secretion of melatonin makes humans sleepy and promotes sleep. For example, in the case of indoor workers who spend most of the day under artificial light, the light they receive is a very important factor. In other words, in order to support the formation of human circadian rhythms, we should be exposed to light that corresponds to the time of day when we are active. It is believed that light that promotes melatonin secretion is preferred.

In recent years, the idea of Human Centric Lighting (HCL), which is human-centered lighting, has begun to spread widely. HCL aims to improve the concentration and circadian rhythm of people who spend time in artificial light such as lighting by adjusting the brightness and color of the lighting. WELL certification (Well Building Standard), which focuses on the health of people working in buildings, is a new certification system for buildings that evaluates human health as well as environmental and energy performance. ), and GBCI (Green Business Certification Incorporated) performs certification. In this WELL certification, lighting that takes circadian rhythms into consideration is listed as an essential certification item. Equivalent Melanopic illuminance is used therein as a quantitative unit of brightness that affects circadian rhythms. The equivalent melanopic illuminance is required to be 250 lux or more on the vertical plane after satisfying the conditions of 75% or more of the office space and 4 hours or more a day. The equivalent melanopic illuminance is obtained by the following formula (1). Further, the calculation of the equivalent melanopic illuminance requires a melanopic ratio determined from the spectral distribution of the light source, which is determined by the following formula (2).

式（２）中、用語「Ｌａｍｐ」は、光源の分光分布を示す。式（２）中、用語「Ｃｉｒｃａｄｉａｎ」は、哺乳類の網膜にある光受容体であるｉｐＲＧＣの感度曲線（吸光度）を表す。式（２）中、用語「Ｖｉｓｕａｌ」は、ヒトの明所視における視感度曲線を表す。

In formula (2), the term "Lamp" indicates the spectral distribution of the light source. In equation (2), the term "Circadian" represents the sensitivity curve (absorbance) of ipRGC, a photoreceptor in the mammalian retina. In equation (2), the term "Visual" represents the luminosity curve in human photopic vision.

The melanopsin (Circadian) response of ipRGC is used for the circadian action curve contained in the spectral distribution of the light source for determining the melanopic ratio. Also, the human luminosity response is used for the luminosity (Visual) curve. As a result, it can be determined that the higher the melanopic ratio, the more strongly the circadian rhythm can be stimulated by the spectral distribution.

As artificial light that supports the formation of human circadian rhythm, there is LED toning dimming lighting. This LED toning dimming lighting controls the LEDs that emit different color tones around the blackbody radiation locus, and obtains mixed-color light to achieve color temperature change (toning) and brightness change (dimming). It is a lighting device that made it possible. In such a lighting device, the melanopic ratio changes as the color is toned, but it is only a change in the ratio of wavelength components according to the change in color temperature. low. Here, since the melanopic ratio is affected by the components in the vicinity of 480 nm to 490 nm, the melanopic ratio tends to increase as the color rendering of the light emitted from the lighting device increases, but the color rendering increases. As a trade-off, luminous efficiency tends to decrease. Therefore, in order to make lighting that takes into account the circadian rhythm, it is necessary to control the melanopic ratio according to the circadian rhythm and maintain the luminous efficiency when the melanopic ratio is controlled.

For example, Patent Document 1 describes a combination of white light having a chromaticity on the black body radiation and blue monochromatic light emitted from a light emitting element as a light emitting device and a lighting device capable of adjusting the chromaticity of emitted light. A light-emitting device has been proposed.

JP 2018-129492 A

However, it is difficult to achieve both control of the melanopic ratio and maintenance of luminous efficiency in conventional toning lighting using LEDs around the black body radiation locus and having different color tones. When adjusting the chromaticity with blue monochromatic light, the color deviation is changed while the color temperature remains substantially the same, so the adjusted chromaticity deviates greatly from the black body radiation. In order to create lighting that takes account of the circadian rhythm, it is necessary to reproduce the changes in sunlight over time. However, there is a problem with the chromaticity at the time of toning. Furthermore, in order to effectively adjust the melanopic ratio according to toning, it is desirable that the combined light source contains a light emitting component with a wavelength of 480 nm to 490 nm, and blue monochromatic light is not sufficiently effective. Further, when the direction in which the chromaticity is adjusted is the negative direction of the color deviation, the luminosity factor decreases from the spectral distribution, resulting in a decrease in luminous efficiency.

An object of one embodiment of the present invention is to provide a light-emitting device capable of achieving both control of the melanopic ratio in consideration of circadian rhythm and maintenance of luminous efficiency.

A first aspect of the present invention is a first light source comprising a first light emitting element having an emission peak wavelength in the range of 410 nm or more and 490 nm or less, and a second light emitting element having an emission peak wavelength in the range of 410 nm or more and 460 nm or less. and a second phosphor, wherein the first light source has chromaticity coordinates of x=0.280 and y=0.070 in the chromaticity diagram of the CIE1931 color system. A first straight line connecting a first point and a second point where x in chromaticity coordinates is 0.280 and y is 0.500, the second point, and x in chromaticity coordinates are a second straight line connecting 0.013 and a third point where y is 0.500; a pure purple locus extending from the first point toward the smaller x value in the chromaticity coordinates; Emit light within the region defined by the spectral locus extending from the three points toward the smaller value of y in the chromaticity coordinates, and in the emission spectrum, the emission intensity I _PL at the maximum emission peak wavelength of the first light emitting element , the emission intensity ratio I _PM /IPL of the emission intensity I _PM at a wavelength of 490 nm is in the range of 0.22 or more and 0.95 or less, and the second light source has a correlation in the chromaticity diagram of the _CIE1931 color system When the color temperature is within the range of 1500K or more and 8000K or less, it emits light whose color deviation duv from the black body radiation locus measured in accordance with JIS Z8725 is within the range of -0.02 or more and 0.02 or less. and a light-emitting device that emits mixed-color light of the light emitted from the first light source and the light emitted from the second light source.
The "pure violet locus" is the locus connecting the ends of the chromaticity diagram formed between the red and violet end spectra. Colors on the pure violet locus are colors (red to reddish purple) that do not exist in monochromatic light, and are colors created by mixing colors. A “spectrum locus” refers to a curve obtained by connecting chromaticity points of monochromatic (pure) light on a chromaticity diagram. The chromaticity diagram of the CIE color system was defined by the International Commission on Illumination (CIE: Commission Internationale de l'Eclairage).
Emission spectra of the first light-emitting element and the second light-emitting element are measured using an omnidirectional integrating sphere, and the wavelength showing the highest emission intensity in the emission spectrum is defined as the emission peak wavelength. The emission intensity at the emission peak wavelength of the first light emitting element is defined as the emission intensity _IPL .
The emission spectrum of the light-emitting device is measured using a spectrofluorophotometer, and the emission intensity at a wavelength of 490 nm in the emission spectrum is defined as the emission intensity _IPM .
The chromaticity coordinates (chromaticity x, y) of the emission color of the light emitting device are measured using an optical measurement system combining a multichannel spectrometer and an integrating sphere.
For the second light source, using an optical measurement system that combines a multichannel spectrometer and an integrating sphere, the chromaticity coordinates of the emitted color (chromaticity x, y), the correlated color temperature (Tcp; K) in accordance with JIS Z8725, and The color deviation duv from the blackbody radiation locus and the general color rendering index Ra were measured according to JIS Z8726.

According to one aspect of the present invention, it is possible to provide a light-emitting device capable of achieving both control of the melanopic ratio in consideration of circadian rhythm and maintenance of luminous efficiency.

FIG. 1 is a schematic cross-sectional view showing an example of a light emitting device. FIG. 2 shows a part of the chromaticity diagram of the CIE1931 color system, the light emitting area LSa of the first light source, the black body radiation locus (duv is 0), and the color from the black body radiation locus at each correlated color temperature FIG. 10 is a diagram showing a trajectory with a deviation duv of −0.02, a duv of −0.01, a duv of 0.01, and a duv of 0.02; FIG. 3 is a schematic cross-sectional view showing another example of the light emitting device. FIG. 4 shows the respective emission spectra at correlated color temperatures of 6500 K, 5000 K, 4000 K, 3000 K, and 2700 K of the mixed color light emitted from the light emitting device according to Example 1, the emission spectrum of only the first light source, and the circadian action curve. and a visibility curve. FIG. 5 shows the respective emission spectra at correlated color temperatures of 6500 K, 5000 K, 4000 K, 3000 K, and 2700 K of the mixed color light emitted from the light emitting device according to Example 2, the emission spectrum of only the first light source, and the circadian action curve. and a visibility curve. 6 is a diagram showing emission spectra, circadian action curves, and luminosity curves at correlated color temperatures of 6500 K, 5000 K, 4000 K, 3000 K, and 2700 K of mixed color light emitted from the light emitting device according to Comparative Example 1. FIG. . FIG. 7 shows respective emission spectra at correlated color temperatures of 6500 K, 5000 K, 4000 K, 3000 K, and 2700 K of the mixed color light emitted from the light emitting device according to Example 3, the emission spectrum of only the first light source, and the circadian action curve. and a visibility curve. FIG. 8 is a diagram showing emission spectra, circadian action curves, and luminosity curves at correlated color temperatures of 6500 K, 5000 K, 4000 K, 3000 K, and 2700 K of mixed color light emitted from the light emitting device according to Comparative Example 2. . FIG. 9 shows respective emission spectra at correlated color temperatures of 6500 K, 5000 K, 4000 K, 3000 K, and 2700 K of the mixed color light emitted from the light emitting device according to Example 4, the emission spectrum of only the first light source, and the circadian action curve. and a visibility curve. FIG. 10 is a diagram showing emission spectra, circadian action curves, and luminosity curves at correlated color temperatures of 6500 K, 5000 K, 4000 K, 3000 K, and 2700 K of mixed color light emitted from the light emitting device according to Comparative Example 3. . FIG. 11 shows the respective emission spectra at correlated color temperatures of 6500 K, 5000 K, 4000 K, 3000 K, and 2700 K of the mixed light emitted from the light emitting device according to Example 5, the emission spectrum of only the first light source, and the circadian action curve. and a visibility curve. FIG. 12 shows the respective emission spectra at correlated color temperatures of 6500 K, 5000 K, 4000 K, 3000 K, and 2700 K of the mixed light emitted from the light emitting device according to Example 6, the emission spectrum of only the first light source, and the circadian action curve. and a visibility curve. FIG. 13 shows the respective emission spectra at correlated color temperatures of 6500 K, 5000 K, 4000 K, 3000 K, and 2700 K of the mixed light emitted from the light emitting device according to Comparative Example 4, the emission spectrum of only the first light source, and the circadian action curve. and a visibility curve. FIG. 14 shows the respective emission spectra at correlated color temperatures of 6500 K, 5000 K, 4000 K, 3000 K, and 2700 K of the mixed light emitted from the light emitting device according to Comparative Example 5, the emission spectrum of only the first light source, and the circadian action curve. and a visibility curve.

A light-emitting device according to the present invention will be described below based on one embodiment. However, the embodiments shown below are examples for embodying the technical idea of the present invention, and the present invention is not limited to the following light emitting devices. The relationship between the color name and chromaticity coordinates, the relationship between the wavelength range of light and the color name of monochromatic light, etc. conform to JIS Z8110.

The light emitting device comprises a first light source comprising a first light emitting element having an emission peak wavelength in the range of 410 nm or more and 490 nm or less, a second light emitting element having an emission peak wavelength in the range of 410 nm or more and 460 nm or less, and a second light emission. a second light source comprising a second phosphor that emits light when excited by the device; In the chromaticity diagram of the CIE 1931 color system, the first light source has a first point with chromaticity coordinates of x of 0.280 and y of 0.070, and a chromaticity coordinate of x of 0.280 and y of 0.070. A first straight line connecting the second point at 0.500 and a second straight line connecting the second point to a third point at which x is 0.013 and y is 0.500 in the chromaticity coordinates. , a pure purple locus extending from the first point toward the smaller x value in the chromaticity coordinates, and a spectrum locus extending from the third point toward the smaller y value in the chromaticity coordinates. (Hereinafter, also referred to as “light emitting area LSa of the first light source”) emits light. The "pure violet locus" is the locus connecting the ends of the chromaticity diagram formed between the red and violet end spectra. Colors on the pure violet locus are colors (red to reddish purple) that do not exist in monochromatic light, and are colors created by mixing colors. A “spectrum locus” refers to a curve obtained by connecting chromaticity points of monochromatic (pure) light on a chromaticity diagram. The chromaticity diagram of the CIE color system was defined by the International Commission on Illumination (CIE: Commission Internationale de l'Eclairage). Further, in the emission spectrum of the light emitting device, the emission intensity ratio I _PM / _IPL of the emission intensity I _PM at a wavelength of 490 nm to the emission intensity I _PL at the maximum emission peak wavelength of the first light emitting element is 0.22 or more and 0.22 or more. It is within the range of 95 or less. The second light source has a color deviation duv from the black body radiation locus measured in accordance with JIS Z8725 when the correlated color temperature is within the range of 1500 K or more and 8000 K or less in the chromaticity diagram of the CIE1931 color system. It emits light within the range of 0.02 to 0.02. The light emitting device emits mixed light of light emitted from the first light source and light emitted from the second light source.
Emission spectra of the first light-emitting element and the second light-emitting element are measured using an omnidirectional integrating sphere, and the wavelength showing the highest emission intensity in the emission spectrum is defined as the emission peak wavelength. The emission intensity at the emission peak wavelength of the first light emitting element is defined as the emission intensity _IPL .
The emission spectrum of the light-emitting device is measured using a spectrofluorophotometer, and the emission intensity at a wavelength of 490 nm in the emission spectrum is defined as the emission intensity _IPM .
The chromaticity coordinates (chromaticity x, y) of the emission color of the light emitting device are measured using an optical measurement system combining a multichannel spectrometer and an integrating sphere.
For the second light source, using an optical measurement system that combines a multichannel spectrometer and an integrating sphere, the chromaticity coordinates of the emitted color (chromaticity x, y), the correlated color temperature (Tcp; K) in accordance with JIS Z8725, and The color deviation duv from the blackbody radiation locus and the general color rendering index Ra were measured according to JIS Z8726.

An example of a light emitting device according to one embodiment of the present invention will be described with reference to the drawings. FIG. 1 is a schematic cross-sectional view showing a light emitting device 100 according to one embodiment of the invention.

The light emitting device 100 includes a first light source 101 including a covering member 50 covering a first light emitting element 11 having an emission peak wavelength in the range of 410 nm or more and 490 nm or less, and a second light source 101 having an emission peak wavelength in the range of 410 nm or more and 460 nm or less. It comprises two light emitting elements 12 and a second light source 102 comprising a fluorescent member 52 containing a second phosphor 72 which is excited by the light from the second light emitting element 12 to emit light. The light emitting device 100 comprises a substrate 103 on which a first light source 101 and a second light source 102 are arranged. In this specification, the phosphor contained in the second light source 102 is called the second phosphor 72 . As will be described later, the phosphor contained in first light source 101 is referred to as first phosphor 71 .

The first light source 101 and the second light source 102 each include molded bodies 41 and 42 and the first light emitting element 11 or the second light emitting element 12 . Each molded body 41, 42 has first leads 21, 22 and second leads 31, 32, respectively, and resin parts 43, 44 containing thermoplastic resin or thermosetting resin are integrally molded. It is. Each molded body 41, 42 forms a recess having a bottom surface and a side surface, and the first light emitting element 11 or the second light emitting element 12 is mounted on the bottom surface of the recess. Each of the first light emitting element 11 and the second light emitting element 12 has a pair of positive and negative electrodes, and the pair of positive and negative electrodes are connected to first leads 21 and 22 and second leads 31 and 32 and wires 61 and 62, respectively. are electrically connected via The first light emitting element 11 or the second light emitting element 12 is covered with a covering member 50 or a fluorescent member 52, respectively. Covering member 50 includes a sealing material. The fluorescent member 52 includes a second phosphor 72 that converts the wavelength of light from the second light emitting element 12 and a sealing material. The first phosphor 71 or the second phosphor 72 is excited by the light from the first light emitting element 11 or the second light emitting element 12 and has at least one emission peak wavelength in a specific wavelength range. Two or more phosphors with different wavelength ranges may be included. Through the first leads 21 and 22 and the second leads 31 and 32, power is supplied from the outside to cause the first light source 101 and the second light source 102 to emit light, and light emitted from the first light source 101 and the second light source 102. mixed color light can be emitted from the light emitting device 100 .

The first light emitting element 11 and the second light emitting element 12 are used as excitation light sources. The first light emitting element 11 has an emission peak wavelength within the range of 410 nm or more and 490 nm or less. In addition, the first light emitting element 11 provided in the first light source 101 may be a plurality of light emitting elements, and the plurality of light emitting elements each have an emission peak wavelength within the above wavelength range, and the emission peaks are different from each other. It may have a wavelength. The second light emitting element 12 has an emission peak wavelength within the range of 410 nm or more and 460 nm or less. In addition, the second light emitting element 12 provided in the second light source 102 may be a plurality of light emitting elements, and the plurality of light emitting elements each have an emission peak wavelength within the above wavelength range, and the emission peaks are different from each other. It may have a wavelength. The half widths of the emission spectra of the first light emitting element 11 and the second light emitting element 12 may be, for example, 30 nm or less, 25 nm or less, or 20 nm or less. The half width refers to the full width at half maximum (FWHM) of the emission peak in the emission spectrum, and refers to the wavelength width of the emission peak that is 50% of the maximum value of the emission peak in each emission spectrum. The first light emitting element 11 and the second light emitting element 12 are, for example, semiconductor light emitting elements using a nitride semiconductor (In _x Al _Y Ga _1-XY N, 0≦X, 0≦Y, X+Y≦1) is preferably By using a semiconductor light-emitting element as the first light-emitting element 11 and the second light-emitting element 12, the stable first light source 101 and the second light source 102 that are highly efficient, have high linearity with respect to input, and are resistant to mechanical impact can be provided. It is possible to obtain a light emitting device having the above.

FIG. 2 shows the light emitting area LSa of the first light source 101 in the chromaticity diagram of the CIE1931 color system. The first light source 101 has a first point (x=0.280, y=0.070) and a second point (x=0.280, y = 0.500) and the second point (x = 0.280, y = 0.500) and the third point (x = 0.013, y = 0.500). A second straight line, a pure purple locus extending from the first point (x = 0.280, y = 0.070) to the smaller x in the chromaticity coordinates, and a third point (x = 0.013, y=0.500) to the smaller of y, which is the area defined by the spectral locus. By the first light source 101 emitting light within the light emitting region LSa of the first light source, light containing light emitting components within a wavelength range of 480 nm to 490 nm can be emitted from the light emitting device. The melanopic ratio can be effectively adjusted according to such toning, and lighting that takes into account the circadian rhythm can be achieved. In this specification, the luminescence component with a wavelength of 480 nm to 490 nm that affects the melanopic ratio is sometimes referred to as a circadian component. First, preferably x is 0.270 and y is 0.063, more preferably x is 0.260 and y is 0.059. Second, preferably x is 0.270 and y is 0.490, more preferably x is 0.260 and y is 0.480. Third, preferably x is 0.014 and y is 0.490, more preferably x is 0.015 and y is 0.480.
A preferable range for the light emitting area LSa in the chromaticity coordinates of the first light source is the first point (x=0.270, y=0.063) and the second point (x=0.270, y=0.063). 490) and a second straight line connecting the second point (x = 0.270, y = 0.490) and the third point (x = 0.014, y = 0.490) A straight line, a pure purple locus extending from the first point (x = 0.270, y = 0.063) to the smaller x in the chromaticity coordinates, and a third point (x = 0.014, y = 0 .490) to the lower y.
A more preferable range for the light emitting area LSa in the chromaticity coordinates of the first light source is the first point (x=0.260, y=0.059) and the second point (x=0.260, y=0 .480) and the second straight line connecting the second point (x = 0.260, y = 0.480) and the third point (x = 0.015, y = 0.480) A straight line, a pure purple locus extending from the first point (x = 0.260, y = 0.059) to the smaller x in the chromaticity coordinates, and a third point (x = 0.015, y = 0.480) to the smaller y.

The first light source 101 has an emission intensity _IPM at a wavelength of 490 nm relative to the emission intensity _IPL at the maximum emission peak wavelength of the first light emitting element 11, which is caused by the light emitted from the first light source 101 in the emission spectrum of the light emitting device. is within the range of _0.22 or more and _0.95 or less. Light with a wavelength of 490 nm is light involved in melanopsin in ipRGC that affects melatonin secretion, and in the emission spectrum, the luminescence intensity at a wavelength of 490 nm is sometimes referred to as _melanopic luminescence intensity IPM. In the emission spectrum of the light emitting device, the emission intensity ratio I _PM /IPL of the _melanopic emission intensity I _PM to the emission intensity I _PL at the maximum emission peak wavelength of the first light emitting element 11 is 0.22 or more and 0.95. Within the following range, it is possible to obtain an emission spectrum close to the circadian action curve in which the melanopsin (Circadian) response of ipRGC was used, and to control the melanopic ratio according to the human circadian rhythm. Furthermore, the light-emitting device can obtain mixed-color light while maintaining desired luminous efficiency from the light emitted from the first light source 101 and the light emitted from the second light source 102 . In the emission spectrum of the light emitting device, when the emission intensity ratio I _PM / _IPL is in the range of 0.22 or more and 0.95 or less, the light from the first light source and the light from the second light source are toned and correlated. When the color temperature is 4000 K or more and 8000 K or less, for example, when the melanopic ratio when the color is toned by the light from the second light sources is 100%, it is relatively within the range of 1% or more and 35% or less. The melanopic ratio can be increased and the melanopic ratio can be controlled to stimulate human circadian rhythms. In the emission spectrum of the light-emitting device, the emission intensity ratio I _PM / _IPL is preferably in the range of 0.25 or more and 0.90 or less, more preferably in the range of 0.29 or more and 0.85 or less, It is more preferably in the range of 0.30 or more and 0.82 or less, and particularly preferably in the range of 0.35 or more and 0.80 or less.

The luminescence intensity I _PM represents the luminescence intensity (melanopic luminescence intensity) at 490 nm, which is the maximum emission peak wavelength of the circadian action curve using the melanopsin response of ipRGC. The luminescence intensity _IPL represents the luminescence intensity at the maximum emission peak wavelength of the excitation light source. The luminescence intensity ratio I _PM /IPL represents the ratio of the _{melanopic luminescence intensity IPM to the luminescence intensity I PL of} the excitation light source. If the luminescence intensity ratio I _PM /IPL is less than 0.22, the _melanopic luminescence intensity with respect to the luminescence intensity of the excitation light source is too small, and the light emitting device cannot control the melanopic ratio according to the human circadian rhythm. . If the luminescence intensity ratio I _PM /IPL exceeds 0.95, the _melanopic luminescence intensity is too large with respect to the luminescence intensity of the excitation light source, and the melanopic ratio cannot be controlled according to the human circadian rhythm.

FIG. 2 shows the blackbody locus and the range of color deviation duv, which is a deviation from the blackbody locus, from −0.02 to 0.02 in the chromaticity diagram of the CIE1931 color system. The second light source has a color deviation duv from the black body radiation locus measured in accordance with JIS Z8725 when the correlated color temperature is within the range of 1500 K or more and 8000 K or less in the chromaticity diagram of the CIE1931 color system. It emits light within the range of 0.02 to 0.02. If the light emitted from the second light source has a color deviation duv from the black body radiation locus measured in accordance with JIS Z8725 within the range of -0.02 or more and 0.02 or less, it affects human luminosity response. It is possible to obtain an emission spectrum that is close to the luminosity curve for which the human luminosity response is used, without reducing the light of the luminosity component that is used. In addition, when the light emitted from the second light source has a color deviation duv from the black body radiation locus in the range of −0.02 or more and 0.02 or less, the light from the first light source that affects the melanopic ratio The mixed light can control the melanopic ratio according to the circadian rhythm, and the mixed light can be obtained while maintaining the luminous efficiency. The second light source has a color deviation duv from the black body radiation locus measured in accordance with JIS Z8725 when the correlated color temperature is within the range of 1500 K or more and 8000 K or less in the chromaticity diagram of the CIE1931 color system. Light within the range of -0.01 to 0.01 may be emitted.

The light emitting device preferably has a correlated color temperature in the range of 1500 K or more and 8000 K or less, and the mixed color light emitted from the light emitting device preferably has a general color rendering index Ra of 70 or more, more preferably a general color rendering index Ra. 75 or more. The general color rendering index Ra of the light emitting device is 100 or less. The general color rendering index Ra of a light-emitting device can be measured according to JIS Z8726. The closer the general color rendering index Ra of the light emitting device is to 100, the closer the luminescent color to the reference light source can be obtained. Since light including a circadian component with a wavelength of 480 nm to 490 nm is emitted from the first light source and the spectral distribution is close to that of the reference light source, the light emitting device can have a relatively high general color rendering index. For example, the correlated color temperature is within the range of 4000 K or more and 8000 K or less by changing the type of phosphor or the like in a single light source without toning by mixed color light of light from the first light source and light from the second light source. When using a light source containing light with a circadian component with a wavelength of 480 nm to 490 nm, the general color rendering index Ra slightly increases, but tends to decrease at a certain point. This is because in the case of a single light source using only a light source containing many circadian components with wavelengths of 480 nm to 490 nm, the color balance of the emission spectrum obtained from the light emitting device is lost. In addition, a light source containing many circadian components with a wavelength of 480 nm to 490 nm tends to reduce visibility and is difficult to use for general lighting purposes. According to the guidelines published by CIE in 1986, the general color rendering index that fluorescent lamps should possess is 60 or more and less than 80 in factories where general work is carried out. The melanopic ratio can be effectively adjusted according to the toning to achieve the desired color temperature, and the light emitted from the first light source and the light emitted from the second light source can be combined to provide lighting that respects the circadian rhythm. The mixed color light of the light may have a general color rendering index Ra of 95 or less.

The first light source 101 preferably includes a first phosphor 71 that emits light when excited by the first light emitting element 11 . FIG. 3 is a schematic cross-sectional view showing a light emitting device 200 according to another embodiment of the invention. A light-emitting device 200 showing another embodiment is different from the light-emitting device 100 in that the first light source 101 includes a fluorescent member 51 containing a first phosphor 71 instead of the covering member 50. are common. The first light source 101 preferably includes a fluorescent member 51 including a first phosphor 71 that emits light when excited by the first light emitting element 11 having an emission peak wavelength in the range of 410 nm or more and 490 nm or less. Since the first light source 101 includes the first phosphor 71, the first light source 101 can be easily adjusted to emit light in a specific light emitting region LSa, and the light emitted from the first light source can be emitted from the second light source. When the light is toned to emit light of a desired correlated color temperature, it facilitates obtaining a mixed color light whose melanopic ratio can be controlled in consideration of the circadian rhythm while maintaining the desired luminous efficiency.

The first phosphor 71 contained in the first light source 101 consists of the following phosphors (A1), (A2), (A3) and (A4) having an emission peak wavelength within the range of 440 nm or more and 526 nm or less. The phosphor A is preferably composed of at least one selected from the group, and may contain two or more phosphors. More preferably, the first phosphor 71 contained in the first light source 101 contains at least the following (A1) alkaline earth metal aluminate phosphor. When the first phosphor 71 contained in the first light source 101 has an emission peak wavelength within the range of 440 nm or more and 526 nm or less, it is possible to suppress a decrease in the emission intensity _IPM .
(A1) An Eu-activated alkaline earth metal aluminate phosphor whose emission spectrum has a half width of preferably 58 nm or more and 78 nm or less, more preferably 63 nm or more and 73 nm or less.
(A2) At least one selected from the group consisting of Ca, Sr and Ba, which has a half width in the emission spectrum of preferably 50 nm or more and 75 nm or less, more preferably 50 nm or more and 60 nm or less. An Eu-activated silicate phosphor having in its composition the elements, Mg, and at least one element selected from the group consisting of F, Cl and Br.
(A3) At least one selected from the group consisting of Ba, Sr and Ca, which has a half width in the emission spectrum of preferably 50 nm or more and 75 nm or less, more preferably 58 nm or more and 68 nm or less. An Eu-activated silicate phosphor having elements in its composition.
(A4) At least selected from the group consisting of Y, Gd, Tb and Lu, having a half width in the emission spectrum of preferably 90 nm or more and 115 nm or less, more preferably 95 nm or more and 110 nm or less A Ce-activated rare earth aluminate phosphor having a composition comprising a rare earth element, Al and optionally Ga.
Full width at half maximum (FWHM) refers to the wavelength width of an emission peak that is 50% of the maximum value of the emission peak in the emission spectrum of a phosphor.

The first light source 101 contains, as the first phosphor 71, a phosphor selected from the group consisting of phosphors (A1), (A2), (A3) and (A4). When the emitted light and the light emitted from the second light source are toned to emit light of a desired correlated color temperature, the chromaticity of the mixed light obtained from the light emitting device is close to the blackbody locus, The color deviation duv is in the range of −0.02 or more and 0.02 or less, and it is possible to obtain mixed color light whose melanopic ratio can be controlled in consideration of circadian rhythm while maintaining desired luminous efficiency. For example, when the correlated color temperature is low and the correlated color temperature is around 3000K to around 2700K, it becomes closer to the light from evening to sunset, and an emission spectrum with a low melanopic ratio is used so that the secretion of melatonin is easily promoted. It is preferred that mixed color light having a color is obtained from the light emitting device. On the other hand, when the correlated color temperature exceeds 3000K and is around 6500K, it becomes close to sunlight from morning to around noon, and the melanopic ratio value that stimulates the circadian rhythm is high so that the secretion of melatonin is easily suppressed. It is preferred that mixed colored light having an emission spectrum is obtained from the light emitting device.

The first phosphor 71 included in the first light source 101 is at least one phosphor selected from the group consisting of phosphors having compositions represented by the following formulas (a1), (a2), (a3), and (a4) is more preferable, and two or more of them may be used in combination. The first light source 101 includes a first phosphor 71 containing at least one phosphor selected from the group consisting of phosphors having compositions represented by formulas (a1), (a2), (a3) and (a4). As a result, light containing many circadian components with a wavelength of 480 nm to 490 nm is obtained, and the mixed light having a general color rendering index Ra of 70 or more by the light emitted from the first light source 101 and the light emitted from the second light source 102. is obtained.
_Sr4Al14O25 : _{Eu (} a1)
(Ca, _Sr ,Ba) _{8MgSi4O16 (} F,Cl,Br) ₂ :Eu (a2)
(Ca, Sr, Ba) ₂ SiO ₄ :Eu (a3)
(Y, Gd, Tb, Lu) ₃ (Al, Ga) ₅ O ₁₂ :Ce (a4)
Here, in the composition formula showing the composition of the phosphor, the plurality of elements described separated by commas (,) means that at least one of these elements is included in the composition, It may contain a combination of two or more of the plurality of elements. In this specification, in the formulas indicating the composition of the phosphor, before the colon (:) represents the elements constituting the host crystal and their molar ratio, and after the colon (:) represents the activating element. A "molar ratio" represents the molar amount of an element in one mole of the composition of the phosphor.

The amount of the first phosphor 71 contained in the first light source 101 depends on the wavelength range of the second light emitting element 12 of the second light source 102 combined with the first light source 101, the type of the second phosphor 72, and the size of the light emitting device 200. Varies depending on The amount of the first phosphor 71 contained in the first light source 101 is such that the light emitted from the first light source 101 is within the light emitting region LSa of the first light source and the emission spectrum of the light emitting device 200 is the same as that of the first light emitting element 11 It is sufficient that the emission intensity ratio I _PM / _IPL of the emission intensity I _PM at a wavelength of 490 nm to the maximum emission peak wavelength I _PL of is within the range of 0.22 or more and 0.95 or less.

The second phosphor 72 included in the second light source 102 includes a second phosphor 72B having an emission peak wavelength in the range of 601 nm or more and less than 650 nm, and a second phosphor having an emission peak wavelength in the range of 650 nm or more and 670 nm or less. 72C and a second phosphor 72A' having an emission peak wavelength in the range of 440 nm or more and 600 nm or less. The second phosphor 72 includes two or more phosphors selected from the group consisting of second phosphors 72A′ having different wavelength ranges of emission peak wavelengths, second phosphors 72B and second phosphors 72C, and may contain three kinds of phosphors. When the second light source 102 contains the phosphor in this way, the white light dimmed to a desired correlated color temperature can be emitted from the second light source 102, and the light emitted from the second light source 102 and , and the light emitted from the first light source 101, it is possible to obtain mixed-color light whose melanopic ratio can be controlled in consideration of the circadian rhythm while maintaining desired luminous efficiency.

Among the second phosphors 72, the second phosphor 72A' having an emission peak wavelength in the range of 440 nm or more and 600 nm or less is the following phosphors (A1), (A2), (A3) and (A4) Preferably, at least one selected from the group consisting of is included, and two or more phosphors may be included. Among the second phosphors 72, the second phosphor 72A' having an emission peak wavelength in the range of 440 nm or more and 600 nm or less is a group of phosphors of the same type as the first phosphor 71 included in the first light source 101. may contain at least one phosphor selected from The second phosphor 72A′ having an emission peak wavelength in the range of 440 nm or more and 600 nm or less may be the same kind of phosphor as the first phosphor 71, or a different kind of phosphor from the first phosphor 71. good too.
(A1) An Eu-activated alkaline earth metal aluminate phosphor whose emission spectrum has a half width of preferably 58 nm or more and 78 nm or less, more preferably 63 nm or more and 73 nm or less.
(A2) At least one selected from the group consisting of Ca, Sr and Ba, which has a half width in the emission spectrum of preferably 50 nm or more and 75 nm or less, more preferably 50 nm or more and 60 nm or less. An Eu-activated silicate phosphor having in its composition the elements, Mg, and at least one element selected from the group consisting of F, Cl and Br.
(A3) At least one element selected from the group consisting of Ba, Sr, and Ca having a half width in the emission spectrum of preferably 50 nm or more and 75 nm or less, more preferably 58 nm or more and 68 nm or less. and activated with Eu.
(A4) At least selected from the group consisting of Y, Gd, Tb and Lu, having a half width in the emission spectrum of preferably 90 nm or more and 115 nm or less, more preferably 95 nm or more and 110 nm or less A Ce-activated rare earth aluminate phosphor having a composition comprising a rare earth element, Al and optionally Ga.

Among the second phosphors 72, the second phosphor 72B having an emission peak wavelength in the range of 601 nm or more and less than 650 nm is selected from the group consisting of the following phosphors (B1), (B2) and (B3) is preferably at least one kind of phosphor, and two or more kinds of phosphors may be included.
(B1) at least one element selected from the group consisting of Sr and Ca, which has a half width in the emission spectrum of preferably 65 nm or more and 100 nm or less, more preferably 70 nm or more and 95 nm or less; , Al, and activated with Eu.
(B2) an Eu-activated alkaline earth metal silicon nitride phosphor having a half width in the emission spectrum of preferably 80 nm or more and 100 nm or less, more preferably 85 nm or more and 95 nm or less; and (B3) a Mn-activated fluoride phosphor having a half-value width in the emission spectrum of preferably 10 nm or less, usually 1 nm or more.

Among the second phosphors 72, the second phosphor 72C having an emission peak wavelength in the range of 650 nm or more and 680 nm or less is at least one selected from the group consisting of the following phosphors (C1) and (C2) are preferably phosphors, and two types may be included.
(C1) A Mn-activated fluorogermanate phosphor whose emission spectrum has a half-value width of preferably 45 nm or less, more preferably 40 nm or less, and usually 1 nm or more.
(C2) At least selected from the group consisting of Ca, Sr, Ba and Mg, wherein the half width in the emission spectrum is preferably in the range of 40 nm or more and 70 nm or less, more preferably in the range of 45 nm or more and 65 nm or less An Eu-activated alkali nitride phosphor having a composition of one element, at least one element selected from the group consisting of Li, Na and K, and Al.

The second phosphor 72 includes a second phosphor 72A' and at least one selected from the second phosphor 72B and the second phosphor 72C, and the second phosphor 72A' is represented by the following formula (a1). an alkaline earth metal aluminate phosphor having a composition represented by the following formula (a2), a silicate phosphor having a composition represented by the following formula (a3), a silicate phosphor having a composition represented by the following formula (a3), and It is preferably at least one selected from the group consisting of rare earth aluminate phosphors having the composition represented by formula (a4), and may be two or more.
_Sr4Al14O25 : _{Eu (} a1)
(Ca, _Sr ,Ba) _{8MgSi4O16 (} F,Cl,Br) ₂ :Eu (a2)
(Ca, Sr, Ba) ₂ SiO ₄ :Eu (a3)
(Y, Gd, Tb, Lu) ₃ (Al, Ga) ₅ O ₁₂ :Ce (a4)

The second phosphor 72B is a silicon nitride phosphor having a composition represented by the following formula (b1), an alkaline earth metal silicon nitride phosphor having a composition represented by the following formula (b2), and a following formula (b3 ) is preferably at least one selected from the group consisting of fluoride phosphors having the composition shown in ), and may be two or more.
(Ca,Sr) _AlSiN3 :Eu (b1)
₍ Ca, Sr, Ba) _2Si5N8 :Eu ₍ b2)
K2 ₍ Si,Ge,Ti) _F6 :Mn (b3)

The second phosphor 72C is at least selected from the group consisting of a fluorogermanate phosphor having a composition represented by the following formula (c1) and an alkali nitride phosphor having a composition represented by the following formula (c2): One type is preferable, and two or more types may be used.
_{3.5MgO.0.5MgF2.GeO2} :Mn ₍ c1)
(Sr, Ca) (Li, Na, K) Al ₃ N ₄ :Eu (c2)

The amount of the second phosphor 72 contained in the second light source 102 varies depending on the type of the first light emitting element 11 of the first light source 101 used in combination, the type of the first phosphor 71, and the size of the light emitting devices 100 and 200. . The amount of the second phosphor 72 contained in the second light source 102 is measured in accordance with JIS Z7825 when the correlated color temperature of the light emitted from the second light source 102 is within the range of 1500K or more and 8000K or less. It is sufficient if the amount is such that the color deviation duv from the black body radiation locus is within the range of −0.02 or more and 0.02 or less.

The first phosphor 71 included in the first light source 101 or the second phosphor 72 included in the second light source 102 are included in the fluorescent members 51 and 52, respectively. The fluorescent members 51 and 52 preferably contain the first fluorescent substance 71 or the second fluorescent substance 72, respectively, and a sealing material. A resin selected from a thermoplastic resin and a thermosetting resin can be used as the sealing material included in the covering member 50, the fluorescent member 51, and the fluorescent member 52. FIG. Resins used as the sealing material include, for example, silicone resins and epoxy resins because they are easy to manufacture. The covering member 50, the fluorescent member 51, and the fluorescent member 52 may contain components such as fillers, light stabilizers, and colorants in addition to the first phosphor or the second phosphor and the sealing material. Examples of fillers include silica, barium titanate, titanium oxide, and aluminum oxide. The contents of the components other than the first phosphor, the second phosphor, and the sealing material in the covering member 50, the phosphor member 51, and the phosphor member 52 are determined according to the size of the target light emitting device and the target mixed color light. It depends on the correlated color temperature, the color deviation duv of the mixed light, and the color tone of the mixed light. For example, the content of components other than the phosphor and the sealing material in the covering member 50, the fluorescent member 51, and the fluorescent member 52 is 0.01 parts by mass or more and 20 parts by mass or less with respect to 100 parts by mass of the sealing material. can be within the range of

The light emitting devices 100 and 200 may comprise multiple first light sources 101 and multiple second light sources 102 . The light emitting devices 100 and 200 independently control the light output of the first light source 101 and the light output of the second light source 102, respectively, and control the color temperature to a desired color temperature. It is preferable to provide a drive device including a drive circuit capable of interlocking with a setting unit that can be set to , and a power supply that receives power supply from the outside. As a light-emitting device having such a driving device, an already known technique such as the technique disclosed in Japanese Patent Application Laid-Open No. 2012-113959 can be used. Equipped with driving devices that independently control the light output from the first light source 101 and the light output from the second light source 102, the light emitting devices 100 and 200 can produce a desired color from a low color temperature to a high color temperature. It is possible to emit mixed light with a desired temperature and chromaticity.

EXAMPLES Hereinafter, the present invention will be specifically described with reference to examples. The invention is not limited to these examples.

Example 1
A light emitting device similar to the light emitting device 200 shown in FIG. 3 was manufactured.

Example 1: First Light Emitting Element 11 and Second Light Emitting Element 12
A nitride semiconductor having an emission peak wavelength of 446 nm was used as the first light emitting element 11 in the first light source 101 and the second light emitting element 12 in the second light source 102 of the light emitting device 200 .
The emission peak wavelengths of the first light emitting element 11 and the second light emitting element 12 were obtained by measuring the emission spectrum using an omnidirectional integrating sphere, and taking the wavelength showing the maximum emission intensity of the emission spectrum as the emission peak wavelength.

Example 1 Sealing Material Used for Fluorescent Members 51 and 52 Silicone resin was used as a sealing material for the fluorescent member 51 in the first light source 101 and the fluorescent member 52 in the second light source 102 .

Example 1: First phosphor 71
The first phosphor 71 contained in the first light source 101 is excited by the light emitted from the first light emitting element ₁₁ , has an emission peak wavelength of 495 nm, and has a composition represented by _Sr4Al14O25 : _Eu . (A1) alkaline earth metal aluminate phosphor (hereinafter also referred to as "SAE phosphor") having a half width of 68 nm was used. The amount of the first phosphor 71 contained in the first light source 101 is such that the light emitted from the first light source 101 is x=0.149 and y=0.234 in the chromaticity diagram of the CIE1931 color system. was used. Further, the amount of the first phosphor 71 contained in the first light source 101 is the emission intensity _IPM at a wavelength of 490 nm with respect to the maximum emission peak wavelength _IPL of the first light emitting element 11 in the emission spectrum of the light emitting device 200. The amount used was such that the ratio I _PM /I _PL fell within the range of 0.22 or more and 0.95 or less.

Example 1: Second phosphor 72
As for the second phosphor 72 included in the second light source 102, two kinds of phosphors are used as the second phosphor A' and one kind of phosphor is used as the second phosphor B, as described below. The second phosphor A′ has an emission peak wavelength of 533 nm when excited by the light emitted from the second light emitting element 12, has a composition represented by Y ₃ Al ₅ O ₁₂ :Ce, and has a half width of 108 nm. (A4-1) a rare earth aluminate phosphor (hereinafter also referred to as a “YAG phosphor”), and having an emission peak wavelength of 538 nm when excited by light emitted from the second light emitting element 12, A rare earth aluminate phosphor having a composition represented by (A4-2) Lu ₃ Al ₅ O ₁₂ :Ce and having a half width of 105 nm (hereinafter also referred to as “LAG phosphor”) was used. As the second phosphor B, (B1) (Sr, Ca)AlSiN ₃ :Eu having an emission peak wavelength of 630 nm when excited by the light emitted from the second light emitting element 12 and a half width of 81 nm. A silicon nitride phosphor (hereinafter also referred to as “SCASN phosphor”) having a composition was used. For the second phosphor 72, the correlated color temperature of the light emitted from the second light source 102 is around 2700 K, the color deviation duv from the black body radiation locus measured in accordance with JIS Z8725 is around 0, or the duv is - An amount within the range of 0.02 or more and 0.02 or less was used, and the general color rendering index Ra of the mixed light of the light emitted from the first light source 101 and the light emitted from the second light source 102 was 75 or more.

Example 1: First light source 101
A silicone resin as a sealing material and the first phosphor 71 were mixed, and the first phosphor 71 was dispersed in the silicone resin to obtain a resin composition for a fluorescent member. This resin composition is filled in the concave portion of the molded body 41 constituting the first light source 101 and heated at 150° C. for 3 hours to cure the resin composition, form the fluorescent member 51 , and form the first light source 101 . manufactured.
For the first light source, the chromaticity coordinates (chromaticity x, y) of the emitted color were measured using an optical measurement system combining a multichannel spectroscope and an integrating sphere.

Example 1: Second light source 102
A silicone resin as a sealing material and the second phosphor 72 were mixed, and the second phosphor 72 was dispersed in the silicone resin to obtain a resin composition for a fluorescent member. This resin composition is filled in the concave portion of the molded body 42 constituting the second light source 102 and heated at 150° C. for 3 hours to cure the resin composition, form the fluorescent member 52 , and form the second light source 102. manufactured.
For the second light source, using an optical measurement system that combines a multichannel spectrometer and an integrating sphere, the chromaticity coordinates of the emitted color (chromaticity x, y), the correlated color temperature (Tcp; K) in accordance with JIS Z8725, and The color deviation duv from the blackbody radiation locus and the general color rendering index Ra were measured according to JIS Z8726.

Example 1: Light emitting device 200
Using the obtained first light source 101 and second light source 102, the light emitting device 200 was manufactured. The light emitting device 200 controls the light output from the first light source 101 and the light output from the second light source 102 so as to obtain mixed-color light of around 3000K, around 4000K, around 5000K, and around 6500K. A first light source 101 and a plurality of second light sources 102 were used. The light emitting device 200 controls the light output of the first light source 101 and the light output of the second light source 102, and has a control unit that can control the color temperature to a desired color temperature, and a setting unit that can set the desired color temperature. By controlling the light output from the first light source 101 and the light output from the second light source 102, mixed color light with desired color temperature and chromaticity can be emitted.

Evaluation Emission Spectrum (Spectral Distribution), Emission Intensity Ratio The emission spectrum (spectral distribution) of the mixed color light emitted from the light emitting device of each example and each comparative example was measured with a spectrofluorophotometer (product name: F-4500, Hitachi High-Technologies Co., Ltd.). company). In the emission spectrum of the light emitting device, the emission intensity ratio I _PM / _IPL of the emission intensity I _PM at a wavelength of 490 nm to the emission intensity I _PL at the maximum emission peak wavelength of the first light emitting element 11 was obtained. The luminescence intensity I _PM represents the luminescence intensity (melanopic luminescence intensity) at 490 nm, which is the maximum emission peak wavelength of the circadian action curve using the melanopsin response of ipRGC. The luminescence intensity _IPL represents the luminescence intensity at the maximum emission peak wavelength of the excitation light source. The luminescence intensity ratio I _PM /IPL represents the ratio of the _melanopic luminescence intensity I _PM to the luminescence intensity I _PL of the excitation light source.

Luminous efficiency (lm/W), chromaticity (x, y), correlated color temperature, general color rendering index Ra
For the light emitting device of each example and comparative example, the total luminous flux (lm) obtained from the light source was divided by the amount of electric power supplied in an optical measurement system combining a multichannel spectrometer and an integrating sphere, and the luminous efficiency (lm/ W), chromaticity coordinates of emitted color (chromaticity x, y), correlated color temperature (Tcp; K) in accordance with JIS Z8725, general color rendering index Ra in accordance with JIS Z8726, special color rendering index R9, R12 was measured. Special color rendering indices R9 and R12 are color rendering indices for evaluating red and blue, respectively. The input current for the measurement of the light-emitting device was 65 mA for the rated forward current of the light-emitting device, and the forward voltage at that time was 2.89V.

Melanopic ratio In order to evaluate the amount of stimulation that the mixed color light emitted from the light emitting device of each example and each comparative example affects the circadian rhythm, from the obtained emission spectrum, by the following formula (2), The melanopic ratio was determined. Assuming that the melanopic ratio of light at each correlated color temperature emitted from the light emitting device of Comparative Example 1 is 100%, the melanopic ratio at each correlated color temperature of each example and each comparative example other than Comparative Example 1 is calculated relative to each other. Expressed as melanopic ratio.

式（２）中、用語「Ｌａｍｐ」は、光源の分光分布を示す。式（２）中、用語「Ｃｉｒｃａｄｉａｎ」は、哺乳類の網膜にある光受容体であるｉｐＲＧＣの感度曲線（吸光度）を表す。式（２）中、用語「Ｖｉｓｕａｌ」は、ヒトの明所視における視感度曲線を表す。

In formula (2), the term "Lamp" indicates the spectral distribution of the light source. In equation (2), the term "Circadian" represents the sensitivity curve (absorbance) of ipRGC, a photoreceptor in the mammalian retina. In equation (2), the term "Visual" represents the luminosity curve in human photopic vision.

Melanopic Luminous Efficiency In order to evaluate how much the mixed color light emitted from the light emitting device of each example and each comparative example affects the circadian rhythm with respect to constant power consumption, the following formula (3) is used. As shown, the melanopic luminous efficiency was determined as the product of the melanopic ratio and the luminous efficiency (lm/w). Assuming that the melanopic luminous efficiency of light emitted from the light emitting device of Comparative Example 1 at each correlated color temperature is 100%, the melanopic luminous efficiency at each correlated color temperature of each example and each comparative example other than Comparative Example 1 is expressed as relative melanopic. It was expressed as luminous efficiency.

Table 1 shows the set color temperature of the first light source and the second light source of the light emitting device according to Example 1, the light emitting element, the first phosphor or the second phosphor, and the coordinates x and y of the chromaticity diagram of the CIE1931 color system. , color deviation, and general color rendering index. Table 2 shows the evaluation results of the light emitting device according to Example 1.

In the light emitting device according to Example 1, the color temperature of the mixed light obtained by toning the light emitted from the first light source and the light emitted from the second light source is around 3000 K, around 4000 K, around 5000 K, and around 6500 K, respectively. Then, compared to the light emitting device according to Comparative Example 1, the relative melanopic ratio increases from 9% to 35% and the relative melanopic luminous efficiency also increases from 5% to 16% as the color temperature increases. From this result, in the case of a correlated color temperature close to sunlight from morning to noon, where the correlated color temperature is 3000K to 6500K, the melanopic ratio is a high value that stimulates the circadian rhythm so that the secretion of melatonin is suppressed. I was able to control it so that In addition, the mixed color light emitted from the light emitting device according to Example 1 had a high emission intensity ratio I _PM /IPL of 0.79, and contained many circadian components with wavelengths of 480 nm to 490 nm that affect the _melanopic ratio. In addition, the light-emitting device according to Example 1 had an average color rendering property Ra, a special color rendering property R9, and a special color rendering property R9, and The color R12 value was high, and it had sufficient color rendering properties in the visual environment in which people perform general work. In particular, at around 3000K, around 4000K, around 5000K, and around 6500K, the average color rendering index Ra of the mixed light emitted from the light emitting device according to Example 1 is 85 or more. Mixed color light especially suitable as human ambient light for production activities was obtained. For example, in the vicinity of 5000 K and 6500 K, the emission spectrum of sunlight is used as the reference light source, and it can be confirmed that the light emitting device according to Example 1 obtains mixed color light approximating sunlight from the light emitting device. , was suitable as lighting considering circadian rhythm.

FIG. 4 shows the emission spectrum of the light emitting device according to Example 1 at correlated color temperatures of around 2700 K, around 3000 K, around 4000 K, around 5000 K, and around 6500 K, the emission spectrum of only the first light source, the circadian action curve, and the luminosity. FIG. 4 shows a curve; In the emission spectrum of the light emitting device according to Example 1, the mixed color light that is adjusted so that the correlated color temperature increases from around 2700K to around 6500K has an increased circadian component with a wavelength of 480 nm to 490 nm. Thus, the light-emitting device according to Example 1 was able to control the melanopic ratio to a high value so as to stimulate the circadian rhythm.

Example 2
As the second phosphor 72 used for the second light source 102, (A4) a YAG phosphor having an emission peak wavelength of 557 nm and a half width of 111 nm, and a YAG phosphor having an emission peak wavelength of 620 nm and a half width of 75 nm. (B1) A light-emitting device 200 was manufactured in the same manner as in Example 1, except that the SCASN phosphor was used.

Table 3 shows the set color temperature of the first light source and the second light source used in the light emitting device according to Example 2, the light emitting element, the first phosphor or the second phosphor, and the coordinate x of the chromaticity diagram of the CIE1931 color system. and y, color deviation, and general color rendering index. Table 4 shows evaluation results of the light emitting device according to Example 2.

In the light emitting device according to Example 2, when the color temperature of the mixed light obtained by toning the light emitted from the first light source and the light emitted from the second light source is around 4000K, around 5000K, and around 6500K, Compared to the light emitting device according to Comparative Example 1, the relative melanopic ratio increased from 15% to 31% and the relative melanopic luminous efficiency also increased from 14% to 20% as the color temperature increased. From this result, in the case of the correlated color temperature close to sunlight from morning to noon when the correlated color temperature is 4000K to 6500K, the melanopic ratio is increased so as to suppress the secretion of melatonin and to stimulate the circadian rhythm. I was able to control it to be a high value. When the mixed color light obtained from the light emitting device according to Example 2 has a correlated color temperature close to the light from evening to sunset in the vicinity of 3000 K to 2700 K, the melanopic An emission spectrum with a low ratio value was obtained, and it was suitable as lighting considering the circadian rhythm. In addition, the mixed color light emitted from the light emitting device according to Example 2 had a high emission intensity ratio I _PM /IPL of 0.79, and contained many circadian components with wavelengths of 480 nm to 490 nm that affect the _melanopic ratio. In addition, the light-emitting device according to Example 2 has an average color rendering property Ra, a special color rendering property R9, and a special color rendering property R12 as the color temperature is adjusted from around 2700 K to around 6500 K and from morning to around noon. The value was high, and it had sufficient color rendering properties in the visual environment where humans perform general work.

FIG. 5 shows the emission spectrum of the light emitting device according to Example 2 at correlated color temperatures of around 2700 K, around 3000 K, around 4000 K, around 5000 K, and around 6500 K, the emission spectrum of only the first light source, the circadian action curve, and the luminosity. FIG. 4 shows a curve; In the emission spectrum of the light emitting device according to Example 2, the mixed color light that is adjusted so that the correlated color temperature increases from around 2700K to around 6500K has an increased circadian component with a wavelength of 480 nm to 490 nm. Thus, the light-emitting device according to Example 2 was able to control the melanopic ratio so as to stimulate the circadian rhythm.

Comparative example 1
One second light source 102 (hereinafter also referred to as “2700K second light source”) similar to Example 1 in which the correlated color temperature is set to around 2700K without using the first light source 101, and the correlated color temperature is set to 6500K. A light-emitting device was manufactured using two second light sources 102 of another second light source 102 (hereinafter also referred to as "6500K second light source") set nearby.

Comparative Example 1: 6500K second light source 102
The 6500K second light source 102 uses a nitride semiconductor having an emission peak wavelength of 446 nm as the second light emitting element 12 . A silicone resin was used as a sealing material for the fluorescent member 52 . The second phosphor 72 contained in the 6500K second light source 102 includes (A4-1) a YAG phosphor having an emission peak wavelength of 533 nm and a half width of 108 nm as the second phosphor A′, and 538 nm. (A4-2) Two types of LAG phosphors are used, and the second phosphor B has an emission peak wavelength of 630 nm and a half width of 63 nm. (B1) SCASN phosphor was used. For the second phosphor 72, the correlated color temperature of the light emitted from the second light source 102 is around 6500K, the color deviation duv measured according to JIS Z8725 is around 0, and the light emitted from the second light source 102 is 2700K. , and 6500K, the amount used is such that the general color rendering index Ra of mixed light with light emitted from the second light source 102 is 85 or more.

Comparative Example 1: Light-Emitting Device A light-emitting device was manufactured using the obtained two second light sources of 2700K second light source 102 and 6500K second light source 102 . By controlling the light output from the 2700K second light source 102 and the light output from the 6500K second light source 102, the light emitting device can obtain mixed color light at around 3000K, around 4000K, around 5000K, and around 6500K. Multiple 2700K secondary light sources 102 and multiple 6500K secondary light sources 102 were used. The light emitting device controls the light output of the 2700K second light source 102 and the light output of the 6500K second light source 102, and has a control unit that can control the color temperature to a desired color temperature and a setting unit that can set the desired color temperature. By controlling the light output from the 2700K second light source 102 and the light output from the 6500K second light source 102, it is possible to emit mixed color light with a desired color temperature and chromaticity. can. The light emitting device can emit light with a low correlated color temperature of 2700 K from the 2700 K second light source 102 whose correlated color temperature is set to a low color temperature of around 2700 K, It is possible to emit light with a high color temperature around 6500K, and by controlling the light output of the 2700K second light source 102 and the light output of the 6500K second light source 102, it is possible to produce a black color from a low color temperature to a high color temperature. It is possible to emit mixed color light having a color deviation duv in the range of −0.02 or more and 0.02 or less from the black body radiation locus including the body radiation locus.

Table 5 shows the set color temperature of the 2700K second light source and the 6500K second light source used in the light emitting device according to Comparative Example 1, the light emitting element, the first phosphor or the second phosphor, and the chromaticity diagram of the CIE1931 color system. Coordinates x and y, color deviation and general color rendering index are given. Table 6 shows the evaluation results of the light emitting device according to Comparative Example 1.

The light-emitting device according to Comparative Example 1 can obtain mixed-color light by toning the light emitted from the 2700K second light source and the light emitted from the 6500K second light source. The melanopic ratio and melanopic luminous efficiency at each correlated color temperature of the light emitting device according to Comparative Example 1 are the standards of the melanopic ratio and melanopic luminous efficiency at each correlated color temperature of the light emitting devices according to Comparative Examples other than Example and Comparative Example 1. Become. The mixed-color light emitted from the light emitting device according to Comparative Example 1 has a low emission intensity ratio I _PM /IPL of 0.19, and has a small amount of circadian components with wavelengths of 480 nm to 490 nm that affect _melanopics . In the light emitting device according to Comparative Example 1, the general color rendering index Ra does not change significantly even when the color temperature is adjusted from around 2700K to around 6500K and from morning to around noon. Ra was lowered.

FIG. 6 is a diagram showing an emission spectrum, a circadian action curve, and a luminosity curve at correlated color temperatures of around 2700 K, around 3000 K, around 4000 K, around 5000 K, and around 6500 K of the light emitting device according to Comparative Example 1. FIG. In the emission spectrum of the light emitting device according to Comparative Example 1, as the correlated color temperature increases from around 2700K to around 6500K, the emission spectrum of the circadian component at wavelengths from 480 nm to 490 nm that stimulates the circadian rhythm tends to slightly increase. . However, the light-emitting device according to Comparative Example 1 has fewer circadian components than the light-emitting device according to Example 1, and is not suitable for lighting considering the circadian rhythm.

Example 3
As the first phosphor 71 used in the first light source 101, (A2) Ca ₈ Mg(SiO ₄ ) A light-emitting device 200 was manufactured in the same manner as in Example ₁ , except that a chlorosilicate phosphor having a composition represented by _4C12 :Eu was used.

Table 7 shows the set color temperature of the first light source and the second light source used in the light emitting device according to Example 3, the light emitting element, the first phosphor or the second phosphor, and the coordinate x of the chromaticity diagram of the CIE1931 color system. and y, color deviation, and general color rendering index. Table 8 shows evaluation results of the light emitting device according to Example 3.

When the color temperature of the mixed light obtained by toning the light emitted from the first light source and the light emitted from the second light source is around 4000K, around 5000K, and around 6500K, respectively, Compared to the light emitting device according to Comparative Example 1, the relative melanopic ratio increased from 10% to 19% and the relative melanopic luminous efficiency also increased from 2% to 8% as the color temperature increased. From this result, in the case of the correlated color temperature close to sunlight from morning to noon, where the correlated color temperature is 4000K to 6500K, the melanopic ratio is high, stimulating the circadian rhythm so that the secretion of melatonin is suppressed. I was able to control it so that In addition, the mixed color light emitted from the light emitting device according to Example 3 has a relatively high emission intensity ratio I _PM /IPL of 0.31, and contains many circadian components with wavelengths of 480 nm to 490 nm that affect the _melanopic ratio. It was suitable as lighting considering circadian rhythm. In addition, the light-emitting device according to Example 3 has an average color rendering property Ra, a special color rendering property R9, and a special color rendering property R12 as the color temperature is adjusted from around 4000K to around 6500K and from morning to around noon. In particular, the general color rendering index Ra is 85 or higher. Thus, the light-emitting device according to Example 3 was particularly suitable as ambient light for human beings during daytime productive activities such as studying, reading, and office work.

FIG. 7 shows the emission spectrum of the light emitting device according to Example 3 at correlated color temperatures of around 2700 K, around 3000 K, around 4000 K, around 5000 K, and around 6500 K, the emission spectrum of only the first light source, the circadian action curve, and the luminosity. FIG. 4 shows a curve; In the emission spectrum of the light emitting device according to Example 3, the mixed color light that is adjusted so that the correlated color temperature increases from around 2700K to around 6500K has an increased circadian component with a wavelength of 480 nm to 490 nm. Thus, the light-emitting device according to Example 3 was able to control the melanopic ratio so as to stimulate the circadian rhythm.

Comparative example 2
One second light source 102 (hereinafter also referred to as "2700K second light source") similar to that of the first embodiment in which the correlated color temperature is set to around 2700K without using the first light source 101, and the correlated color temperature is set to 6500K. A light-emitting device was manufactured using two second light sources 102 of another second light source 102 (hereinafter also referred to as "6500K second light source") set nearby.

Comparative Example 2: 6500K second light source 102
The 6500K second light source 102 uses a nitride semiconductor having an emission peak wavelength of 446 nm as the second light emitting element 12 . A silicone resin was used as a sealing material for the fluorescent member 52 . The second phosphor 72 contained in the 6500K second light source 102 is (A2) Ca ₈ Mg(SiO ₄ ) ₄ having an emission peak wavelength of 515 nm and a half width of 58 nm as the second phosphor A′. A chlorosilicate phosphor having a composition represented by C1 ₂ :Eu and a YAG phosphor (A4) having an emission peak wavelength of 533 nm and a half width of 108 nm were used as the second phosphor B. , 630 nm and a half width of 81 nm, (B1) SCASN phosphor was used. For the second phosphor 72, the correlated color temperature of the light emitted from the second light source 102 is around 6500K, the color deviation duv measured according to JIS Z8725 is around 0, and the light emitted from the second light source 102 is 2700K. , and 6500K, the amount used is such that the general color rendering index Ra of mixed light with light emitted from the second light source 102 is 95 or more.

Table 9 shows the set color temperature of the 2700K second light source and the 6500K second light source used in the light emitting device according to Comparative Example 2, the light emitting element, the first phosphor or the second phosphor, and the chromaticity diagram of the CIE1931 color system. Coordinates x and y, color deviation and general color rendering index are given. Table 10 shows the evaluation results of the light emitting device according to Comparative Example 2.

The light-emitting device according to Comparative Example 2 can obtain mixed-color light by toning the light emitted from the 2700K second light source and the light emitted from the 6500K second light source. The color temperature of the mixed light obtained from the light emitting device according to Comparative Example 2 has higher relative melanopic ratios than the light emitted from the light emitting device according to Comparative Example 1 at around 4000K, around 5000K, and around 6500K. However, the value of the relative melanopic ratio is higher from around 2700K to around 3000K, and when the color temperature is close to that of light from evening to sunset, the secretion of melatonin should be promoted. secretion is suppressed, and light that disturbs sleep is emitted. In other words, the light-emitting device according to Comparative Example 2 is not suitable for lighting considering the circadian rhythm. Further, the mixed color light emitted from the light emitting device according to Comparative Example 2 has an emission intensity ratio I _PM / _IPL of 0.21, and the emission intensity ratio I _PM of the mixed color light emitted from the light emitting device according to Comparative Example 1 is 0.21. / _IPL , but the luminous efficiency is low. It is comparable to the relative melanopic luminous efficiency of light. Further, the general color rendering index Ra, the special color rendering index R9, and the special color rendering index R12 of the mixed light emitted from the light emitting device according to Comparative Example 2 are higher than those in Comparative Example 1, and the desired luminous efficiency is maintained. there is However, in the light emitting device according to Comparative Example 2, as described above, the value of the relative melanopic ratio is high from around 2700K to around 3000K where the correlated color temperature is low, and the melanopic ratio cannot be controlled. The lighting is not well thought out.

FIG. 8 is a diagram showing an emission spectrum, a circadian action curve, and a luminosity curve at correlated color temperatures of around 2700 K, around 3000 K, around 4000 K, around 5000 K, and around 6500 K of the light emitting device according to Comparative Example 2. FIG. In the emission spectrum of the light emitting device according to Comparative Example 2, as the correlated color temperature increases from around 2700 K to around 6500 K, the emission spectrum of the circadian component at wavelengths from 480 nm to 490 nm that stimulates the circadian rhythm tends to slightly increase. . However, the light-emitting device according to Comparative Example 2 has fewer circadian components than the light-emitting device according to Example 3, and is not suitable for lighting considering the circadian rhythm.

Example 4
As the first phosphor 71 used in the first light source 101, (A4) LAG phosphor, which is excited by the light emitted from the first light emitting element 11 and has an emission peak wavelength of 496 nm and a half width of 96 nm, is used. A light-emitting device 200 was manufactured in the same manner as in Example 1, except that the light-emitting device 200 was made.

Table 11 shows the set color temperature of the first light source and the second light source used in the light emitting device according to Example 4, the light emitting element, the first phosphor or the second phosphor, and the coordinate x of the chromaticity diagram of the CIE1931 color system. and y, color deviation, and general color rendering index. Table 12 shows the evaluation results of the light emitting device according to Example 4.

In the light-emitting device according to Example 4, the color temperatures of mixed light obtained by toning the light emitted from the first light source and the light emitted from the second light source are around 3000 K, around 4000 K, around 5000 K, and around 6500 K, respectively. Then, compared to the light emitting device according to Comparative Example 1, the relative melanopic ratio increases from 4% to 24% and the relative melanopic luminous efficiency also increases from 1% to 13% as the color temperature increases. From this result, when the correlated color temperature is close to sunlight from morning to noon, from around 3000K to around 6500K, the melanopic ratio is high, stimulating the circadian rhythm so that the secretion of melatonin is suppressed. I was able to control the value. In addition, the mixed color light emitted from the light emitting device according to Example 4 has a relatively high emission intensity ratio I _PM /IPL of 0.50, and contains many circadian components with wavelengths of 480 nm to 490 nm that affect the _melanopic ratio. board. In addition, the light-emitting device according to Example 4 has an average color rendering property Ra, a special color rendering property R9, and a special color rendering property R12 as the color temperature is adjusted from around 3000K to around 6500K and from morning to around noon. The value is high, and it has sufficient color rendering properties in the visual environment where humans perform general work. Especially at around 3000K, around 4000K, around 5000K, and around 6500K, the average color rendering index Ra of the mixed light emitted from the light emitting device according to Example 4 is 75 or more. It is possible to obtain mixed color light that is particularly suitable as environmental light for humans when performing production activities. For example, in the vicinity of 5000 K and 6500 K, the emission spectrum of sunlight is used as the reference light source, and it can be confirmed that the light emitting device according to Example 4 produces mixed-color light approximating sunlight. It was suitable as a considerate lighting.

FIG. 9 shows the emission spectrum of the light emitting device according to Example 4 at correlated color temperatures of around 2700 K, around 3000 K, around 4000 K, around 5000 K, and around 6500 K, the emission spectrum of only the first light source, the circadian action curve, and the luminosity. FIG. 4 shows a curve; In the emission spectrum of the light-emitting device according to Example 4, mixed-color light that is toned so that the correlated color temperature increases from around 2700 K to around 6500 K has an increased circadian component with a wavelength of 480 nm to 490 nm, stimulating the circadian rhythm. , and the light-emitting device according to Example 4 was very suitable as illumination considering circadian rhythms.

Comparative example 3
One second light source 102 (hereinafter also referred to as “2700K second light source”) whose correlated color temperature is set to around 2700 K in the same manner as in Example 1 without using the first light source 101, and the correlated color temperature A light-emitting device was manufactured using two second light sources 102 of another second light source 102 (hereinafter also referred to as "6500K second light source") set to around 6500K.

Comparative Example 3: 2700K second light source 102
The 2700K second light source 102 uses a nitride semiconductor having an emission peak wavelength of 446 nm as the second light emitting element 12 . A silicone resin was used as a sealing material for the fluorescent member 52 . The second phosphor 72 contained in the 2700K second light source 102 is (A2) Ca ₈ Mg(SiO ₄ ) ₄ having an emission peak wavelength of 523 nm and a half width of 63 nm as the second phosphor A′. C1 ₂ : Using two types of a chlorosilicate phosphor having a composition represented by Eu and a (A4-2) LAG phosphor having an emission peak wavelength of 538 nm and a half width of 105 nm, a second phosphor B has an emission peak wavelength of 640 nm and a half width of 92 nm; (B1) SCASN phosphor; and second phosphor C has an emission peak wavelength of 660 nm and a half width of 31 nm. (C1) 3.5MgO·0.5MgF ₂ ·GeO ₂ : Four types of phosphors, fluorogermanate phosphors (hereinafter also referred to as “MGF phosphors”) having a composition represented by Mn were used. .

Comparative Example 3: 6500K second light source 102
The 6500K second light source 102 uses a nitride semiconductor having an emission peak wavelength of 446 nm as the second light emitting element 12 . A silicone resin was used as a sealing material for the fluorescent member 52 . The second phosphor 72 contained in the 6500K second light source 102 includes (A1) an SAE phosphor having an emission peak wavelength of 495 nm and a half width of 68 nm as the second phosphor A′, and an SAE phosphor that emits light at 544 nm. (B1 (C1) _{3.5MgO.0.5MgF.sub.2.GeO.sub.2} :Mn having an emission peak wavelength of 660 nm and a half width of 31 nm as the _second phosphor C, using an SCASN phosphor. A MGF phosphor having a composition was used. A second light source 102 was manufactured in the same manner as in Comparative Example 1 except that these second phosphors 72 were used. For the second phosphor 72, the correlated color temperature of the light emitted from the second light source 102 is around 6500K, the color deviation duv measured according to JIS Z8725 is around 0, and the light emitted from the second light source 102 is 2700K. , and 6500K, the amount used is such that the general color rendering index Ra of mixed light with light emitted from the second light source 102 is 95 or more.

Table 13 shows the set color temperature of the 2700K second light source and the 6500K second light source used in the light emitting device according to Comparative Example 3, the light emitting element, the first phosphor or the second phosphor, and the chromaticity diagram of the CIE1931 color system. Coordinates x and y, color deviation and general color rendering index are given. Table 14 shows the evaluation results of the light emitting device according to Comparative Example 3.

The light-emitting device according to Comparative Example 3 can obtain mixed-color light by toning the light emitted from the 2700K second light source and the light emitted from the 6500K second light source. The relative melanopic ratios of the color temperature of the mixed light obtained from the light emitting device according to Comparative Example 3 are higher than that of the light emitted from the light emitting device according to Comparative Example 1 at around 4000K, around 5000K, and around 6500K. However, the value of the relative melanopic ratio is higher from around 2700K to around 3000K, and when the color temperature is close to that of light from dusk to sunset, the secretion of melatonin should be promoted originally, but the secretion of melatonin is reduced. It is suppressed and emits light that disturbs sleep. In other words, the light-emitting device according to Comparative Example 3 is not suitable for lighting considering the circadian rhythm. Further, the mixed color light emitted from the light emitting device according to Comparative Example 3 has an emission intensity ratio I _PM / _IPL of 0.33, and the emission intensity ratio I _PM of the mixed color light emitted from the light emitting device according to Comparative Example 1 is 0.33. / _IPL , but the luminous efficiency is low. Lower than the relative melanopic luminous efficiency of light. Further, the general color rendering index Ra, the special color rendering index R9, and the special color rendering index R12 of the mixed light emitted from the light emitting device according to Comparative Example 3 are relatively high, and the desired luminous efficiency is maintained. However, in the light emitting device according to Comparative Example 3, as described above, the value of the relative melanopic ratio is high from around 2700K to around 3000K where the correlated color temperature is low. As described above, the light-emitting device according to Comparative Example 3 cannot control the melanopic ratio, and does not provide illumination that takes into consideration the circadian rhythm.

FIG. 10 is a diagram showing emission spectra, circadian action curves, and luminosity curves at correlated color temperatures of around 2700K, around 3000K, around 4000K, around 5000K, and around 6500K of the light emitting device according to Comparative Example 3. FIG. In the emission spectrum of the light-emitting device according to Comparative Example 3, as the correlated color temperature increases from around 2700K to around 6500K, the emission spectrum of the circadian component with a wavelength of 480 nm to 490 nm, which stimulates the circadian rhythm, tends to increase slightly. . However, the light-emitting device according to Comparative Example 3 has fewer circadian components than the light-emitting device according to Example 3, and is not suitable for lighting considering the circadian rhythm.

Example 5
As the first phosphor 71 used in the first light source 101, (A4) LAG phosphor, which is excited by the light emitted from the first light emitting element 11 and has an emission peak wavelength of 517 nm and a half width of 97 nm, is used. A light-emitting device 200 was manufactured in the same manner as in Example 1, except that the light-emitting device 200 was made.

Table 15 shows the set color temperature of the first light source and the second light source used in the light emitting device according to Example 5, the light emitting element, the first phosphor or the second phosphor, and x on the chromaticity diagram of the CIE1931 color system. and y, color deviation, and general color rendering index. Table 16 shows the evaluation results of the light emitting device according to Example 5.

The light emitting device according to Example 5 has a color temperature of about 4000 K, about 5000 K, and about 6500 K when the color temperature of the mixed light obtained by toning the light emitted from the first light source and the light emitted from the second light source is around 4000 K, around 5000 K, and around 6500 K, respectively. Compared to the light emitting device according to Comparative Example 1, the relative melanopic ratio increased from 5% to 18% and the relative melanopic luminous efficiency also increased from 3% to 11% as the color temperature increased. From this result, when the correlated color temperature is close to sunlight from morning to around noon, from 4000K to 6500K, the melanopic ratio becomes a high value that stimulates the circadian rhythm so that the secretion of melatonin is suppressed. I was able to control it. In addition, the mixed color light emitted from the light emitting device according to Example 5 has a relatively high emission intensity ratio I _PM /IPL of 0.41, and effectively eliminates the circadian component with a wavelength of 480 nm to 490 nm that affects the _melanopic ratio. contained. Further, the light-emitting device according to Example 5 had an average color rendering Ra, a special color rendering R9, and a special color rendering The value of R12 was high, and in particular, the general color rendering index Ra was 70 or more, and it had sufficient color rendering properties in the visual environment in which humans perform general work.

FIG. 11 shows the emission spectrum of the light emitting device according to Example 5 at correlated color temperatures of around 2700 K, around 3000 K, around 4000 K, around 5000 K, and around 6500 K, the emission spectrum of only the first light source, the circadian action curve, and the luminosity. FIG. 4 shows a curve; In the emission spectrum of the light-emitting device according to Example 5, mixed-color light that is toned so that the correlated color temperature increases from around 2700 K to around 6500 K has an increased circadian component with a wavelength of 480 nm to 490 nm, stimulating the circadian rhythm. The melanopic ratio could be controlled to give It was confirmed that the light-emitting device according to Example 5 produced mixed-color light approximating that of sunlight, and was suitable for lighting considering the circadian rhythm.

Example 6
As the first phosphor 71 used in the first light source 101, (A4) YAG phosphor, which is excited by the light emitted from the first light emitting element 11 and has an emission peak wavelength of 517 nm and a half width of 104 nm, is used. A light-emitting device 200 was manufactured in the same manner as in Example 1, except that the light-emitting device 200 was made.

Table 17 shows the set color temperature of the first light source and the second light source used in the light emitting device according to Example 6, the light emitting element, the first phosphor or the second phosphor, and x on the chromaticity diagram of the CIE1931 color system. and y, color deviation, and general color rendering index. Table 18 shows the evaluation results of the light emitting device according to Example 6.

The light-emitting device according to Example 6 has a color temperature of about 4,000 K, about 5,000 K, and about 6,500 K when the color temperature of the mixed light obtained by toning the light emitted from the first light source and the light emitted from the second light source is around 4000 K, 5000 K, and 6500 K, Compared to the light emitting device according to Comparative Example 1, the relative melanopic ratio increased from 6% to 12% and the relative melanopic luminous efficiency also increased from 2% to 9% as the color temperature increased. From this result, when the correlated color temperature is close to sunlight from morning to noon, from around 4000K to around 6500K, the circadian rhythm is stimulated so that the secretion of melatonin is suppressed, and the melanopic ratio is increased. I was able to control the value. In addition, the mixed color light emitted from the light emitting device according to Example 6 has a relatively high emission intensity ratio I _PM /IPL of 0.29, and contains many circadian components with wavelengths of 480 nm to 490 nm that affect the _melanopic ratio. board. In addition, the light-emitting device according to Example 6 had an average color rendering property Ra, a special color rendering property R9, and a special color rendering property R12 as the color temperature was adjusted from around 4000K to around 6500K and from morning to around noon. In particular, the general color rendering index Ra is 85 or higher. This indicates that the light-emitting device according to Example 6 is particularly suitable as ambient light for human beings during daytime productive activities such as study, reading, and office work.

FIG. 12 shows the emission spectrum of the light emitting device according to Example 6 at correlated color temperatures of around 2700 K, around 3000 K, around 4000 K, around 5000 K, and around 6500 K, the emission spectrum of only the first light source, the circadian action curve, and the luminosity. FIG. 4 shows a curve; In the emission spectrum of the light-emitting device according to Example 6, mixed-color light that is toned so that the correlated color temperature increases from around 2700 K to around 6500 K has an increased circadian component with a wavelength of 480 nm to 490 nm, stimulating the circadian rhythm. The melanopic ratio could be controlled to give It was confirmed that the light-emitting device according to Example 6 produced mixed-color light approximating sunlight, and the light-emitting device according to Example 6 was suitable for lighting considering the circadian rhythm.

Comparative example 4
A light-emitting device was manufactured using a first light source 101, which will be described later, and a second light source 102 similar to that of Example 1 whose correlated color temperature was set to around 2700K (hereinafter, also referred to as "2700K second light source"). As the first phosphor 71 used in the first light source 101, (A2) Ca ₈ Mg(SiO ₄ ) A chlorosilicate phosphor having a composition represented by ₄ C1 ₂ :Eu was used. For the first phosphor 71 contained in the first light source 101, the amount of x=0.199 and y=0.265 in the chromaticity diagram of the CIE1931 color system was used. In addition, the amount of the first phosphor 71 contained in the first light source 101 is the maximum emission peak wavelength I The amount used was such that the emission intensity ratio I _PM /I _PL of the emission intensity I _PM at a wavelength of 490 nm to the _PL was 0.14. A light-emitting device 200 was manufactured in the same manner as in Example 1, except that this first light source 101 was used. Since the emission peak wavelength of the first phosphor 71 contained in the first light source 101 is 527 nm, the emission intensity ( _melanopic emission intensity) IPM of the light emitting device of Comparative Example 4 is small. Therefore, the emission intensity ratio I _PM / _IPL of the light emitting device of Comparative Example 4 is less than 0.22.

Table 19 shows the set color temperature of the first light source 101 and the second light source 102 used in the light emitting device 200 according to Comparative Example 4, the light emitting element, the first phosphor or the second phosphor, and the chromaticity diagram of the CIE 1931 color system. coordinates x and y, color deviation, and general color rendering index. Table 20 shows the evaluation results of the light emitting device according to Comparative Example 4.

The light-emitting device according to Comparative Example 4 can obtain mixed-color light by toning the light emitted from the first light source and the light emitted from the 2700K second light source. The mixed color light obtained from the light emitting device according to Comparative Example 4 has a relative melanopic ratio at around 4000 K, around 5000 K, and around 6500 K that is slightly higher than the light emitted from the light emitting device according to Comparative Example 1 by 1% to 5%. However, the relative melanopic luminous efficiency was 3% to 5% lower than the emitted light from the light emitting device according to Comparative Example 1. The mixed color light emitted from the light emitting device according to Comparative Example 4 has an emission intensity ratio I _PM / _IPL of 0.14, and the emission intensity ratio I _PM /I of the mixed color light emitted from the light emitting device according to Comparative Example 1 is 0.14. Since it is lower than _PL and the luminous efficiency is also low, the relative melanopic luminous efficiency is low, and the effect of affecting the circadian rhythm is small with respect to constant power consumption, and it is not suitable as lighting considering the circadian rhythm. Further, the general color rendering index Ra, the special color rendering index R9, and the special color rendering index R12 of the mixed light emitted from the light emitting device according to Comparative Example 4 are approximately the same as those in Comparative Example 1. This indicates that while the light emitting device according to Comparative Example 4 maintains the desired luminous efficiency, it does not provide illumination that takes into consideration the circadian rhythm, as described above.

FIG. 13 is a diagram showing emission spectra, circadian action curves, and luminosity curves at correlated color temperatures of around 2700 K, around 3000 K, around 4000 K, around 5000 K, and around 6500 K of the light emitting device according to Comparative Example 4. FIG. In the emission spectrum of the light-emitting device according to Comparative Example 4, even when the correlated color temperature increases from around 2700 K to around 6500 K, the emission spectrum of the circadian component at wavelengths from 480 nm to 490 nm that stimulates the circadian rhythm remains almost unchanged. It has few components and is not suitable as lighting considering circadian rhythm.

Comparative example 5
A light-emitting device was manufactured using a first light source 101, which will be described later, and a second light source 102 similar to that of Example 1 whose correlated color temperature was set to around 2700K (hereinafter, also referred to as "2700K second light source"). As the first phosphor 71 used in the first light source 101, _{Si6 - zAlzOz} having an emission peak wavelength of 540 nm when excited by the light emitted from the first light emitting element 11 and a half width of 55 nm. A β-sialon phosphor having a composition represented by N _8-z :Eu (0<z≦4.2) was used. For the first phosphor 71 contained in the first light source 101, the amount of x=0.234 and y=0.293 in the chromaticity diagram of the CIE1931 color system was used. In addition, the amount of the first phosphor 71 contained in the first light source 101 is the maximum emission peak wavelength I The amount used was such that the emission intensity ratio I _PM /I _PL of the emission intensity I _PM at a wavelength of 490 nm to the _PL was 0.02. A light-emitting device 200 was manufactured in the same manner as in Example 1, except that this first light source 101 was used. Since the emission peak wavelength of the first phosphor 71 contained in the first light source 101 is 540 nm, the emission intensity ( _melanopic emission intensity) IPM of the light emitting device of Comparative Example 5 is small. Therefore, the emission intensity ratio I _PM / _IPL of the light emitting device of Comparative Example 5 is less than 0.22.

Table 21 shows the set color temperature of the first light source and the second light source used in the light emitting device according to Comparative Example 5, the light emitting element, the first phosphor or the second phosphor, and x on the chromaticity diagram of the CIE1931 color system. and y, color deviation, and general color rendering index. Table 22 shows the evaluation results of the light emitting device according to Comparative Example 5.

The light-emitting device according to Comparative Example 5 is a light-emitting device that can obtain mixed-color light by toning the light emitted from the first light source and the light emitted from the 2700K second light source. The mixed color light obtained from the light emitting device according to Comparative Example 5 has a relative melanopic ratio at around 3000 K, around 4000 K, around 5000 K, and around 6500 K, which is lower than the light emitted from the light emitting device according to Comparative Example 1, and has a relative melanopic luminous efficiency. was also lower than the emitted light from the light emitting device according to Comparative Example 1. The mixed color light emitted from the light emitting device according to Comparative Example 5 has an emission intensity ratio I _PM / _IPL of 0.02, and the emission intensity ratio I _PM /I of the mixed color light emitted from the light emitting device according to Comparative Example 1 is 0.02. Since it is considerably lower than _PL and has a low luminous efficiency, the relative melanopic luminous efficiency is low, and it has almost no effect on the circadian rhythm, and is not suitable as lighting considering the circadian rhythm. Further, the general color rendering index Ra, the special color rendering index R9, and the special color rendering index R12 of the mixed light emitted from the light emitting device according to Comparative Example 5 are also higher than those of the mixed light emitted from the light emitting device according to Comparative Example 1. It was low, and the light emitting device according to Comparative Example 5 could not maintain the desired luminous efficiency.

14A and 14B show emission spectra, circadian action curves, and luminosity curves at correlated color temperatures of around 2700K, around 3000K, around 4000K, around 5000K, and around 6500K of the light emitting device according to Comparative Example 5. FIG. In the emission spectrum of the light-emitting device according to Comparative Example 5, even when the correlated color temperature increases from around 2700K to around 6500K, the emission spectrum of the circadian component at wavelengths from 480 nm to 490 nm that stimulates the circadian rhythm hardly changes. As described above, the light-emitting device according to Comparative Example 5 has a very small circadian component, and is not suitable for lighting considering the circadian rhythm.

The light-emitting device of one embodiment of the present invention can both control the melanopic ratio according to the circadian rhythm and maintain the luminous efficiency. That is, since the light-emitting device of one embodiment of the present invention can perform lighting suitable for the concept of HCL, it can be used as a light-emitting device for lighting in consideration of circadian rhythms in accordance with WELL certification requirements.

11: first light emitting element, 12: second light emitting element, 41, 42: molding, 50: coating member, 51, 52: fluorescent member, 71: first phosphor, 72, 72A', 72B, 72C: second Two phosphors, 101: first light source, 102: second light source, 103: substrate, 100, 200: light emitting device.

Claims (8)

a first light source comprising a first light emitting element having an emission peak wavelength in the range of 410 nm or more and 490 nm or less;
A second light source comprising a second light emitting element having an emission peak wavelength in the range of 410 nm or more and 460 nm or less, and a second phosphor that emits light when excited by the second light emitting element,
In the chromaticity diagram of the CIE 1931 color system, the first light source has a first point with chromaticity coordinates of x of 0.280 and y of 0.070, and a chromaticity coordinate of x of 0.280 and y is 0.500, a first straight line connecting the second point, and a third point with chromaticity coordinates of x=0.013 and y=0.500; a fourth point where x is 0.149 and y is 0.234 in chromaticity coordinates, a third straight line connecting the third point, and the fourth point , a fourth straight line connecting said first points, and emitting light within an area defined by
In the emission spectrum of the light emitting device, the emission intensity ratio I _PM / _IPL of the emission intensity I _PM of the light emitting device at a wavelength of 490 nm to the emission intensity I _PL at the maximum emission peak wavelength of the first light emitting element is 0.22 or more. is within the range of 0.95 or less,
The second light source has a color deviation duv from the black body radiation locus measured in accordance with JIS Z8725 when the correlated color temperature is in the range of 1500 K or more and 8000 K or less in the chromaticity diagram of the CIE1931 color system. emit light within the range of -0.02 to 0.02;
A light-emitting device having a correlated color temperature in the range of 1500K or more and 5000K or less, and emitting mixed light of light emitted from the first light source and light emitted from the second light source. 2. The light emitting device according to claim 1, wherein said mixed light has a general color rendering index of 70 or higher. 3. The light-emitting device according to claim 1, wherein said first light source comprises a first phosphor that emits light when excited by said first light-emitting element. The first phosphor has an emission peak wavelength within the range of 440 nm or more and 526 nm or less,
(A1) an Eu-activated alkaline earth metal aluminate phosphor having a half width in the emission spectrum of 58 nm or more and 78 nm or less;
(A2) from the group consisting of at least one element selected from the group consisting of Ca, Sr, and Ba, and Mg, F, Cl, and Br, and having a half width in the emission spectrum of 50 nm or more and 75 nm or less; at least one element selected, and an Eu-activated silicate phosphor having in its composition;
(A3) Eu-activated silicate having a half-value width in the emission spectrum of 50 nm or more and 75 nm or less, having a composition of at least one element selected from the group consisting of Ba, Sr and Ca. a phosphor, and (A4) at least one rare earth element having a half width in the emission spectrum of 90 nm or more and 115 nm or less and selected from the group consisting of Y, Gd, Tb and Lu, Al, and optionally 4. The light-emitting device of claim 3, comprising at least one phosphor A selected from the group consisting of Ce-activated rare earth aluminate phosphors having in composition Ga and Ga accordingly. The second phosphor is at least one selected from a second phosphor B having an emission peak wavelength in the range of 601 nm or more and less than 650 nm and a second phosphor C having an emission peak wavelength in the range of 650 nm or more and 670 nm or less. and a second phosphor A' having an emission peak wavelength in the range of 440 nm or more and 600 nm or less,
The second phosphor A' is
(A1) an alkaline earth metal aluminate phosphor that has a half width in the emission spectrum of 58 nm or more and 78 nm or less and is activated by Eu;
(A2) from the group consisting of at least one element selected from the group consisting of Ca, Sr, and Ba, and Mg, F, Cl, and Br, and having a half width in the emission spectrum of 50 nm or more and 75 nm or less; at least one element selected, and an Eu-activated silicate phosphor having in its composition;
(A3) Eu-activated silicate having a half-value width in the emission spectrum of 50 nm or more and 75 nm or less, having a composition of at least one element selected from the group consisting of Ba, Sr and Ca. a phosphor, and (A4) at least one rare earth element having a half width in the emission spectrum of 90 nm or more and 115 nm or less and selected from the group consisting of Y, Gd, Tb and Lu, Al, and optionally At least one selected from the group consisting of rare earth aluminate phosphors activated with Ce, having Ga and, accordingly, in the composition,
The second phosphor B is
(B1) The half width in the emission spectrum is in the range of 65 nm or more and 100 nm or less, has a composition of at least one element selected from the group consisting of Sr and Ca, and Al, and is activated with Eu silicon nitride phosphor,
(B2) an Eu-activated alkaline earth metal silicon nitride phosphor with a half-value width in the emission spectrum of 80 nm or more and 100 nm or less; and (B3) a half-value width in the emission spectrum of 10 nm or less. , at least one selected from the group consisting of Mn-activated fluoride phosphors,
The second phosphor C is
(C1) an Mn-activated fluorogermanate phosphor with an emission spectrum half-width of 45 nm or less; and (C2) an emission spectrum with a half-width of 40 nm or more and 70 nm or less, Ca, A composition comprising at least one element selected from the group consisting of Sr, Ba and Mg, at least one element selected from the group consisting of Li, Na and K, and Al, and activated with Eu 5. The light-emitting device according to claim 1, wherein the phosphor is at least one selected from the group consisting of alkali nitride phosphors. The first phosphor is an alkaline earth metal aluminate phosphor having a composition represented by the following formula (a1), a silicate phosphor having a composition represented by the following formula (a2), and a following formula (a3) and at least one selected from the group consisting of a silicate phosphor having a composition represented by the following formula (a4) and a rare earth aluminate phosphor having a composition represented by the following formula (a4). Luminescent device.
_Sr4Al14O25 : _{Eu (} a1)
(Ca, _Sr ,Ba) _{8MgSi4O16 (} F,Cl,Br) ₂ :Eu (a2)
(Ca, Sr, Ba) ₂ SiO ₄ :Eu (a3)
(Y, Gd, Tb, Lu) ₃ (Al, Ga) ₅ O ₁₂ :Ce (a4) The second phosphor includes a second phosphor A' and at least one selected from the second phosphor B and the second phosphor C,
The second phosphor A' is an alkaline earth metal aluminate phosphor having a composition represented by the following formula (a1), a silicate phosphor having a composition represented by the following formula (a2), and the following formula ( At least one selected from the group consisting of a silicate phosphor having a composition represented by a3) and a rare earth aluminate phosphor having a composition represented by the following formula (a4),
The second phosphor B is a silicon nitride phosphor having a composition represented by the following formula (b1), an alkaline earth silicon nitride phosphor having a composition represented by the following formula (b2), and a following formula (b3) ) is at least one selected from the group consisting of fluoride phosphors having a composition represented by
The second phosphor C is selected from the group consisting of a fluorogermanate phosphor having a composition represented by the following formula (c1) and an alkali nitride phosphor having a composition represented by the following formula (c2). 7. The light emitting device according to any one of claims 1 to 6, which is at least one kind.
_Sr4Al14O25 : _{Eu (} a1)
(Ca, _Sr ,Ba) _{8MgSi4O16 (} F,Cl,Br) ₂ :Eu (a2)
(Ca, Sr, Ba) ₂ SiO ₄ :Eu (a3)
(Y, Gd, Tb, Lu) ₃ (Al, Ga) ₅ O ₁₂ :Ce (a4)
(Ca,Sr) _AlSiN3 :Eu (b1)
₍ Ca, Sr, Ba) _2Si5N8 :Eu ₍ b2)
K2 ₍ Si,Ge,Ti) _F6 :Mn (b3)
_{3.5MgO.0.5MgF2.GeO2} :Mn ₍ c1)
(Sr, Ca) (Li, Na, K) Al ₃ N ₄ :Eu (c2) 8. The light emitting device according to any one of claims 1 to 7, comprising a driving device that independently controls said first light source and said second light source.

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