Light-emitting device

Abstract

Provided is a light-emitting device capable of creating a light environment in which biological rhythms can be adjusted and ensuring high color rendering properties at various color temperatures. A light-emitting device of the present invention is characterized by comprising: a first light-emitting body that emits light having a peak wavelength in a wavelength range of 480-510 nm and having a wavelength width characteristic that has a half-value wavelength width on both sides of 20 nm or less, a second light-emitting body that emits light having a peak wavelength in a wavelength range of 440-480 nm and having a wavelength width characteristic that has a half-value wavelength width on both sides of 20 nm or less, and a wide-light light-emitting body that emits light having a peak wavelength different from the peak wavelengths of light emitted by the first light-emitting body and the second light-emitting body in a wavelength range of 450-700 nm and having a wavelength width characteristic that has a half-value wavelength width on both sides of 30 nm or more; and a controller capable of independently controlling the emission intensity of the light emitted from the first light-emitting body, the second light-emitting body, and the wide-light light-emitting body.

Description

Light-emitting device

[0001] The present invention relates to a light-emitting device capable of adjusting biological rhythms.

[0002] The biological rhythms that humans are innately equipped with are affected by the lighting environment, such as the illuminance, color temperature, and spectral distribution of light experienced over time. The lighting environment is involved in the sleep-wake rhythm of the daily biological rhythm, as well as the quality of sleep, such as how well we fall asleep when we go to bed, how we wake up during sleep, and how well we feel when we wake up. Sleep quality therefore affects human health. Therefore, an appropriate lighting environment is necessary for a healthy human life.

[0003] For example, living in a 24-hour modern society under artificial lighting conditions is known to cause sleep disorders and depression. To solve this problem, it is necessary to improve biological rhythms. Therefore, it has been proposed to reduce the illuminance of the lighting environment as much as possible, especially at night, and to reduce the amount of short-wavelength light. However, a certain level of brightness is necessary to ensure workability and safety in daily life. Furthermore, cutting out extreme short-wavelength light results in a decrease in color rendering. Thus, improving artificial lighting presents a dilemma: reducing the adverse effects on biological rhythms while ensuring the brightness and color rendering required for daily life.

[0004] Furthermore, the biological rhythms of hospitalized patients and those requiring care who spend most of their day in or around their beds in, for example, hospital rooms in medical facilities or nursing homes, are strongly affected by artificial lighting environments. In particular, hospitalized patients and those requiring care who spend most of their day near corridors, where natural light is often insufficient, are more strongly affected by artificial lighting environments.

[0005] Artificial lighting used in hospital rooms and living spaces is required to have the brightness (illuminance) and color temperature necessary for the work and activities of hospitalized patients and those requiring care, as well as high color rendering properties that allow doctors, nurses, and caregivers to accurately grasp the skin color and facial expressions of hospitalized patients and those requiring care. However, living in such an artificial lighting environment disrupts the biological rhythms of hospitalized patients and those requiring care and reduces their sleep quality. Disruption of the biological rhythms and reduced sleep quality of hospitalized patients and those requiring care increase the burden on nurses and caregivers at night, so it has been pointed out that improving the lighting environment with artificial lighting is necessary to adjust biological rhythms.

[0006] For example, Patent Document 1 discloses a lighting system that includes a specific light source (blue light source) having a peak wavelength in the range of 450 nm to 480 nm, a dimming light source consisting of a white light source and an incandescent light source, and a control unit that controls the light emission intensity of each light source. The lighting system changes the light emission intensity of the specific light source according to the time of day, thereby improving biological rhythms while engaging in daily activities. Blue light (light with a wavelength around 460 nm) contained in the light emitted by the specific light source is known to suppress melatonin secretion. Since high melatonin secretion promotes sleep and low melatonin secretion suppresses sleep, the lighting system reduces the light emission intensity of the specific light source during the sleep period from evening (5:00 PM) to the wake-up time (5:00 AM) the following morning, and increases the light emission intensity of the specific light source during other periods.

[0007] In addition, a lighting system has been proposed that uses two types of light sources with different light colors and light distributions, and by adjusting the output ratio of these two types of light sources to an appropriate value, it is possible to create a lighting environment that regulates biological rhythms without causing any discomfort in the way the viewer sees (Patent Document 2).

[0008] JP 2014-54290 A JP 2018-32538 A

[0009] Berson DM, Dunn FA, Takao M.: Phototransduction by retinal ganglion cells that set the circadian clock. Science 295: 1070-1073, 2002. Morita T., Tokura H.: The influence of different wavelengths of light on human biological rhythms. Applied Human Science 17(3): 91-96, 1998. Tanaka M, Fukuda H, Morita K: The effects of daytime light stimulation of melanopsin-containing retinal ganglion cells on nocturnal melatonin secretion and sleepiness. Journal of Physiological Anthropology of Japan 24(4); 141-148, 2019.

[0010] The lighting system described in Patent Document 1 does not take color rendering into consideration, and may result in unnatural appearance depending on the object. In addition, although the lighting system described in Patent Document 2 takes color rendering into consideration, it produces high glare during the day and reduces illuminance before bedtime, making it insufficient for application to patient rooms in medical facilities or rooms in nursing homes.

[0011] The problem to be solved by the present invention is to provide a light emitting device that can create a lighting environment that can adjust the biological rhythm and can ensure high color rendering properties at various color temperatures.

[0012] The light emitting device according to the present invention, which has been made to solve the above-mentioned problems, is characterized by comprising: a light emitting unit including: a first light emitter that emits light having a peak wavelength in a wavelength range of 480 nm to 510 nm and having a wavelength width characteristic in which the double-sided half-maximum wavelength width is 20 nm or less; a second light emitter that emits light having a peak wavelength in a wavelength range of 440 nm to 480 nm and having a wavelength width characteristic in which the double-sided half-maximum wavelength width is 20 nm or less; and a wide light light emitter that emits light having a peak wavelength in a wavelength range of 450 nm to 700 nm that is different from both the peak wavelengths of the light emitted by the first light emitter and the second light emitter, and having a wavelength width characteristic in which the half-maximum wavelength width on the long wavelength side is 30 nm or more; and a control unit that can independently control the emission intensities of the light emitted by the first light emitter, the second light emitter, and the wide light light emitter.

[0013] In the present invention, "peak wavelength" refers to the wavelength of the peak top observed in the spectrum of light emitted by a light emitter. Furthermore, "half-maximum wavelength width" refers to the wavelength width of the peak at a position where the emission intensity is 50% of the peak top, and "half-maximum wavelength width on the long wavelength side" and "half-maximum wavelength width on the short wavelength side" refer to the width on the long wavelength side and the width on the short wavelength side, respectively, of the wavelength width of the peak at a position where the emission intensity is 50% of the peak top.

[0014] The first light emitter, the second light emitter, and the wide-beam light emitter preferably use light-emitting diodes (LEDs) as light sources in terms of ease of control of light emission intensity, but are not limited thereto and may also use, for example, incandescent lamps or fluorescent lamps. Furthermore, each light emitter may be composed of one light source or multiple light sources. When the light emitter is composed of multiple light sources, all the light sources may be the same type, or multiple types of light sources may be mixed.

[0015] In general, light information received by the retina is transmitted to the brain via two different pathways. One pathway is transmitted to the visual cortex of the brain via cones and rods, resulting in the perception of brightness and color, which are visual system functions. The other pathway is transmitted to the suprachiasmatic nucleus, the center of the biological clock, resulting in non-visual system functions, such as the light response of biological rhythms (such as regulating the phase and amplitude of core body temperature and melatonin secretion rhythms). Melanopsin-expressing retinal ganglion cells (hereinafter referred to as "mRGCs") play an important role in non-visual system functions (Non-Patent Document 1). In the following explanation, cones (L-cones, M-cones, S-cones), rods, and mRGCs, which transmit light received by the retina to the brain, are referred to as "photoreceptors."

[0016] The inventors have clarified the effects of multi-wavelength light sources, such as red, green, and blue light with localized spectral distributions and high and low color temperature light with ubiquitous spectral distributions, on melatonin secretion in the pineal gland and have pointed out problems with the spectral distribution of artificial lighting used in our living environment (Non-Patent Document 2). By adjusting the wavelength composition of the illumination light and using metamerism (the phenomenon in which two objects appear to have the same color under certain light wavelength configuration conditions), we have established a method for selectively and independently stimulating the photoreceptors on the retina while ensuring the brightness (illuminance), light color (color temperature), and color rendering properties required for daily activities.

[0017] In the light-emitting device according to the present invention, the peak wavelength of the light emitted by the first light emitter is close to the peak sensitivity wavelength (505 nm) of the rods, which are the photoreceptors on the retina, and the peak wavelength of the light emitted by the second light emitter is close to the peak sensitivity wavelength (445 nm) of the S-cones and the peak sensitivity wavelength (490 nm) of the mRGCs. Furthermore, the broad-band light emitter emits light with a broad wavelength spectrum having a wide (or large) half-maximum wavelength width, and this light may include the peak sensitivity wavelength of the rods, the peak sensitivity wavelength of the mRGCs, the peak sensitivity wavelength of the M-cones (540 nm), and the peak sensitivity wavelength of the L-cones (570 nm). Because the light-emitting unit is composed of light emitters having such characteristic wavelength characteristics, the above-described method can be realized by using the light-emitting device according to the present invention.

[0018] That is, by increasing or decreasing the luminous intensity of light emitted by the first light emitter, which is one of the light emitters constituting the light-emitting unit, the amount of stimulation to the rods can be controlled, and by increasing or decreasing the luminous intensity of light emitted by the second light emitter, the amount of stimulation to the mRGCs and S-cones can be controlled. Furthermore, by increasing or decreasing the luminous intensity of light emitted by the wide-band light emitter, the amount of stimulation to the rods, mRGCs, M-cones, and L-cones can be controlled. That is, by independently increasing or decreasing the luminous intensity of light emitted by all of the light emitters constituting the light-emitting unit, the amount of stimulation to each light receiver can be adjusted, along with the illuminance, color temperature, and color rendering properties of the light emitted by the light-emitting unit. Therefore, it is possible to vary the amount of stimulation to the mRGCs while maintaining a constant amount of stimulation to the cones and rods (luminance, color, and illuminance of light), or to vary the amount of stimulation to the cones and rods while maintaining a constant amount of stimulation to the mRGCs.

[0019] The amount of stimulation that the light emitted from the light-emitting unit provides to the light receiver is calculated by multiplying the spectral radiant energy distribution of the emitted light by the spectral sensitivity distribution of the light receiver. The inventors have previously applied metamerism to an LED lighting device equipped with multiple LEDs with different emission wavelengths, and studied the effect of light stimulation to mRGCs on melatonin secretion and sleepiness in humans under conditions in which the stimulation levels to cones (L-cones, M-cones, S-cones) and rods were kept constant, while the output of each LED was adjusted to vary the stimulation level to mRGCs (Non-Patent Document 3). Based on the findings of this research, by appropriately increasing or decreasing the light emission intensities of the first and second light-emitting elements and the wide-beam light-emitting element throughout the day, a lighting environment capable of regulating biological rhythms can be achieved without impairing work efficiency or behavior in daily life.

[0020] In the light emitting device according to the present invention, the broad light emitting element includes: a third emitting element that emits light having a peak wavelength within a wavelength range of 450 nm to 470 nm, and having a wavelength width characteristic in which the half-maximum wavelength width on the short wavelength side is 20 nm or less and the half-maximum wavelength width on the long wavelength side is 50 nm or more; a fourth emitting element that emits light having a peak wavelength within a wavelength range of 540 nm to 550 nm, and having a wavelength width characteristic in which the half-maximum wavelength width on the short wavelength side and the half-maximum wavelength width on the long wavelength side are each 30 nm or more; and a fifth emitting element that emits light having a peak wavelength within a wavelength range of 620 nm to 650 nm, and having a wavelength width characteristic in which the half-maximum wavelength width on the short wavelength side is 30 nm or more and the half-maximum wavelength width on the long wavelength side is 40 nm or more; and it is preferable that the control unit be able to independently control the emission intensities of the light emitted by the third to fifth emitting elements.

[0021] In the light-emitting device having the above configuration, the peak wavelength of the light emitted by the third light emitter is close to the peak wavelength of sensitivity of the mRGC, the peak wavelength of the light emitted by the fourth light emitter is close to the peak wavelength of sensitivity of the M-cone, and the peak wavelength of the light emitted by the fifth light emitter is close to the peak wavelength of sensitivity of the L-cone. By using five types of light emitters corresponding to the peak wavelengths of sensitivity of the five types of photoreceptors on the retina, respectively, it is possible to finely adjust the amount of stimulation that the light emitted from the light emitter exerts on each of the five types of photoreceptors. Therefore, by appropriately controlling the emission intensity of the light emitted by each light emitter, it is possible to adjust the light emitted from the light emitter so that the amount of stimulation to the mRGC, color temperature, brightness (illuminance), and color rendering index (general color rendering index, specific color rendering index) are optimal.

[0022] In the light-emitting device having the above configuration, it is preferable that the control unit controls the light emission intensity of the light emitted by each of the light-emitting elements so that the color temperature of the light emitted by the light-emitting unit is in the range of 2500 K to 15000 K. This makes it possible to obtain emitted light equivalent to the light emitted by various commercially available artificial light sources (incandescent light bulbs, fluorescent lights (warm white to daylight white)), and emitted light roughly equivalent to natural light (sunlight) experienced indoors and outdoors at various times of the day and in various weather conditions.

[0023] The light emitting device of the present invention further comprises a setting unit that sets the color temperature and mRGC ​​stimulation amount, and a memory unit that stores information indicating the relationship between the color temperature and mRCG stimulation amount of the light emitted from the light emitting unit and the light emission intensity of the light emitted by each of the first light emitter, the second light emitter, and the wide-light light emitter (third to fifth light emitters), and it is preferable that the control unit is configured to control the light emission intensity of each light emitter based on the information so that the color temperature and mRCG stimulation amount of the light emitted from the light emitting unit become the color temperature and mRGC ​​stimulation amount set in the setting unit.

[0024] The information stored in the storage unit can be obtained, for example, by the following procedure: That is, the light emission distribution characteristics of each light emitter are measured in advance, the light emission intensity of the light emitted by each light emitter (light emission intensity of the light emitter) when the color temperature of the light emitted from the light emitter becomes a specified value is calculated, and a combination of the light emission intensities of all the light emitters constituting the light emitter is made to correspond to the color temperature of the light emitted from the light emitter. Usually, there are multiple combinations of light emission intensities of light emitters when the color temperature of the emitted light becomes a specified value, so multiple combinations of light emission intensities of light emitters correspond to one color temperature.

[0025] Next, for a plurality of combinations of the light emission intensities of the light emitters corresponding to the color temperatures, the stimulation amount to the mRGC, the general color rendering index, and the special color rendering index are calculated. For example, if the light emission intensities of five types of light emitters can be changed in 100 steps, then the 100 ５ For each of the 10 billion combinations, the amount of stimulation to the mRGC ​​(mRGC stimulation amount), the general color rendering index, and the specific color rendering index are calculated. ５ From the combinations, combinations with the same mRGC ​​stimulation amount are extracted, and from these combinations, a combination of light-emitting intensities of light-emitting elements with high general color rendering index and high specific color rendering index (referred to as an "optimal combination") is selected. Once optimal combinations have been selected from multiple combinations of light-emitting intensities of light-emitting elements corresponding to all color temperatures, these optimal combinations are stored in a memory unit as information in a data table linked to color temperatures and mRGC ​​stimulation amounts.

[0026] By storing the data table obtained by the above procedure in the storage unit, the control unit can read out from the data table a combination of the light-emitting intensities of the light-emitting elements corresponding to the color temperature and mRGC ​​stimulus amount set in the setting unit, and adjust the light-emitting intensities of each light-emitting element. By using such a data table, the light-emitting intensities of each light-emitting element can be controlled without delay after the color temperature and mRGC ​​stimulus amount are set. Furthermore, it becomes easy to change the mRGC ​​stimulus amount while maintaining the color temperature constant, or to change the color temperature while maintaining the mRGC ​​stimulus amount constant.

[0027] Furthermore, by storing the above-mentioned optimal combination of light emission intensities as a data table, the light emission intensity of each light emitter can be quickly adjusted even if the color temperature or mRGC ​​stimulation amount is increased or decreased, and the general color rendering index and special color rendering index can be maintained at an optimal state at all times, thereby minimizing the impact on workability and behavior in daily life.

[0028] The setting unit may have values ​​for the color temperature and the mRGC ​​stimulus amount set in advance, or may be provided with a setting value input unit for a user to input the values ​​for the color temperature and the mRGC ​​stimulus amount, and the values ​​for the color temperature and the mRGC ​​stimulus amount input through the setting value input unit may be set in the setting unit. Also, a control program (time schedule) for increasing or decreasing the color temperature and the mRGC ​​stimulus amount depending on the time period may be stored in the storage unit using a clock function required for adjusting the daily biological rhythm, and the setting unit may set the color temperature and the mRGC ​​stimulus amount according to the control program, and the control unit may control the light emission intensity of each light emitter.

[0029] By using the light emitting device according to the present invention, it is possible to create a lighting environment that allows adjustment of biological rhythms, and also to ensure high color rendering properties at a variety of color temperatures.

[0030] 1. A schematic diagram of a first embodiment of the light-emitting device of the present invention. 2. A diagram of the optical characteristics of the first to fifth light-emitting bodies (LEDs). 3. An example of a distribution map of color temperature and mRGC ​​stimulation amount that satisfy the conditions of an average color rendering index (Ra) ≧ 90, and special color rendering indexes R9 (red) and R15 (skin color) ≧ 90. 4. An explanatory diagram of a method for increasing or decreasing color temperature and mRGC ​​stimulation amount. 5. An example of a distribution map of color temperature and mRGC ​​stimulation amount that satisfy the conditions of an average color rendering index (Ra) ≧ 70, and special color rendering indexes R9 (red) and R15 (skin color) ≧ 70. 6. An example of a distribution map of color temperature and mRGC ​​stimulation amount that satisfy the conditions of an average color rendering index (Ra) ≧ 80, and special color rendering indexes R9 (red) and R15 (skin color) ≧ 80. 7. A table showing the schedule of Experiment 1. 8. A graph showing the average melatonin concentration at each time from 6:00 PM to midnight. A graph showing the amount of change from the average melatonin concentration from 18:00 to 19:00 to the average melatonin concentration from 23:00 to 24:00. A table showing the schedule of Experiment 2. A graph showing the state of change in the total increase in melatonin secretion from 21:00 to 24:00. A diagram showing a modified example of the light-emitting device according to the present invention. A schematic diagram of a mirror around which light-emitting devices according to the present invention are installed.

[0031] An embodiment of the present invention, in which the present invention is applied to a light-emitting device installed on the ceiling of a patient room in a medical facility or a room in a nursing home, will be described below with reference to the drawings. Fig. 1 is a schematic diagram of the light-emitting device. The light-emitting device 1 includes a light-emitting unit 10 and a light-emitting control unit 20.

[0032] The light-emitting unit 10 includes a rectangular container-shaped housing 11, a substrate 12 arranged on the inner bottom thereof, five types of light-emitting elements, LEDs 101 to 105, arranged on the substrate 12, and a drive circuit 13 for these LEDs 101 to 105. One side of the housing 11 is open, and the opening is covered with a diffusion plate (not shown) that transmits and diffuses the light from the light-emitting elements 101 to 105. While Fig. 1 shows an example in which round LEDs are mounted on the substrate 12, the shape of the LEDs is not limited to round, and they may be rectangular or bulb-shaped.

[0033] The light-emission control unit 20 controls the operation of the light-emitting elements 101 to 105 of the light-emitting unit 10, and includes a light-emission control circuit 201, a memory unit 202, a setting unit 203, a wireless communication unit 204, and a clock circuit 205 as functional blocks. It also includes an input unit 21 and a display unit 22. The memory unit 202 stores a plurality of data sets each consisting of a combination of values ​​for the illuminance, color temperature, and mRCG stimulus amount of light emitted from the light-emitting unit 10, and a data table showing the relationship between the light-emission intensity of the light emitted by the light-emitting elements 101 to 105 corresponding to each data set. The memory unit 202 also stores a time table showing the light-emission intensity of the light emitted by the light-emitting elements 101 to 105 for each day of the year. These data tables and time tables will be described later.

[0034] The light-emitting control unit 20 is actually a general-purpose computer, and the functions of the above-mentioned functional blocks are realized by running dedicated control software installed on the computer. Therefore, the input unit 21 includes a pointing device such as a keyboard and a mouse. The light-emitting device 1 is designed so that values ​​of illuminance, color temperature, and mRGC ​​can be input through the input unit 21, and these input values ​​are set in the setting unit 203.

[0035] The light-emission control unit 20 also includes an external connection terminal 206, which is a connection terminal for a wired communication network such as a USB port, an Ethernet port, an RS-232C port, etc. The light-emission control unit 20 can send and receive data to and from a personal computer or other external device via the external connection terminal 206.

[0036] In addition, the wireless communication unit 204 is capable of communicating with a mobile terminal 30 such as a smartphone, and the user can set the color temperature of the light emitted from the light-emitting unit 10, mRGC, in the setting unit 203 by operating the mobile terminal 30.

[0037] The five types of LEDs 101 to 105 have different peak wavelengths, and multiple LEDs of each type are arranged in multiple rows on the substrate 12 in the order of LEDs 101, 102, 103, 104, and 105. In Fig. 1, the five types of LEDs 101 to 105 are represented by different patterns.

[0038] FIG. 2 is a diagram showing the optical characteristics of LEDs 101 to 105. LED 101 corresponds to the first illuminant of the present invention and is a single-wavelength cyan LED with a peak wavelength of 505 nm and a half-maximum wavelength width of approximately ±10 nm (half-maximum wavelength width on both sides: 20 nm). LED 102 corresponds to the second illuminant of the present invention and is a single-wavelength blue LED with a peak wavelength of 445 nm and a half-maximum wavelength width of approximately ±10 nm (half-maximum wavelength width on both sides: 20 nm). LED 103 corresponds to the third illuminant of the present invention and is an LED with wavelength width characteristics of a peak wavelength of 455 nm to 460 nm and a half-maximum wavelength width of approximately +50 nm (half-maximum wavelength width on the long wavelength side: 50 nm). LED 104 corresponds to the fourth illuminant of the present invention and is an LED with wavelength width characteristics of a peak wavelength of 540 nm and a half-maximum wavelength width of approximately +30 nm (half-maximum wavelength width on the long wavelength side: 30 nm). LED 105 corresponds to the fifth light emitter of the present invention and has wavelength width characteristics of a peak wavelength of 640 nm and a half-maximum wavelength width of approximately ±60 nm (the half-maximum wavelength width on the short wavelength side is 60 nm, and the half-maximum wavelength width on the long wavelength side is 60 nm). LEDs 103 to 105 also correspond to wide-band light emitters of the present invention. In this embodiment, LEDs 103 to 105 are all blue LEDs coated with a phosphor to achieve the above-described peak wavelength and wavelength width characteristics. Note that, in FIG. 2, the optical spectra of LEDs 101 to 105 are normalized so that the peak levels are the same. However, the ratio of the peak levels of each LED 101 to 105 may be set to an appropriate value depending on the illuminance, color temperature, and mRCG stimulation amount of the light emitted from light-emitting unit 10.

[0039] Next, the data table and time table will be described. As described above, the data table associates a plurality of data sets, each of which is a combination of values ​​of the illuminance, color temperature, and mRCG stimulus amount of the light emitted from the light-emitting unit 10, with the light emission intensity of the light emitted by the LEDs 101 to 105.

[0040] The light emission control circuit 201 includes a circuit that uses PWM control to change the light emission intensity of each of the first to fifth LEDs 101 to 105. For example, when PWM control is performed with 8-bit resolution, it is possible to control the light emission intensity using a value between 0 and 255. In other words, a value of 0 means the light is off, and a value of 255 means the light is at its maximum intensity.

[0041] Therefore, first, the spectral irradiance of the maximum light emission intensity of each of the first to fifth LEDs 101 to 105 is measured using a spectrophotometer (Konica Minolta: CL-500A), and the spectral sensitivity coefficients of each photoreceptor (L, M, S-cone, mRGC, rod) are multiplied by the measurement result of the spectral irradiance, and integrated over the wavelength range of 400 nm to 750 nm, and the stimulation amount to the mRGC ​​(Melanopic ELR) is calculated using the calculation method defined in CIE S 026 / E:2018. Then, using the calculation results, the color temperature, mRGC ​​stimulus amount, illuminance, average color rendering index (Ra), and special color rendering indexes R9 (red) and R15 (skin color) are calculated when the PWM output values ​​of the first to fifth LEDs 101 to 105 are changed, and a data table is stored in the memory unit 202 that corresponds pairs (data sets) of color temperatures and mRGC ​​stimulus amounts that satisfy the conditions of average color rendering index (Ra) ≧ 90 and special color rendering indexes R9 (red) and R15 (skin color) ≧ 90 to pairs of light emission intensities of the first to fifth LEDs 101 to 105 at that time.

[0042] Figure 3 is a distribution diagram of the color temperature and mRGC ​​stimulation level for each pair contained in the data table obtained as described above. The vertical axis of the distribution diagram in Figure 3 represents color temperature (K), and the horizontal axis represents mRGC ​​stimulation level (Melanopic ELR, mW / lm).

[0043] From the distribution diagram of FIG. 3, it can be seen that one combination of PWM output values ​​(0 to 255) of the first to fifth LEDs 101 to 105 to achieve emitted light with a color temperature of, for example, 12,000 K is as shown in Table 1 below.

[0044] Furthermore, it can be seen that one combination of PWM output values ​​of the first to fifth LEDs 101 to 105 to achieve emitted light with a color temperature of, for example, 3000K is as shown in Table 2 below.

[0045] Furthermore, as can be seen from the distribution diagram in Figure 3, the combinations of color temperature and mRGC ​​stimulus level that satisfy the conditions of an average color rendering index (Ra) ≥ 90 and special color rendering indexes R9 (red) and R15 (skin color) ≥ 90 include multiple combinations with the same color temperature but different mRGC ​​stimulus levels, and multiple combinations with the same mRGC ​​stimulus level but different color temperatures. This shows that the mRGC ​​stimulus level can be varied between 0.6 and 0.8 mW / lm for a color temperature of 3000 K, between 1.0 and 1.2 mW / lm for a color temperature of 5000 K, and between 1.5 and 1.8 mW / lm for a color temperature of 12000 K. Similarly, it can be seen that the color temperature can be varied between 4000 and 5000K when the mRGC ​​stimulation amount is 1 mW / lm, and between 7000 and 11000K when the mRGC ​​stimulation amount is 1.5 mW / lm.

[0046] In other words, as shown in Figure 4, which adds circled numbers and arrows to the distribution diagram, it is possible to realize a light-emitting device 1 that can transition from a high color temperature and high mRGC ​​stimulus amount to a medium color temperature and medium mRGC ​​stimulus amount (1 → 2), gradually decrease the mRGC ​​stimulus amount while maintaining a constant color temperature (2 → 3), lower the color temperature while maintaining a constant mRGC ​​stimulus (3 to 6), or transition from a medium color temperature and medium mRGC ​​stimulus amount to a low color temperature and low mRGC ​​stimulus amount (6 to 14).

[0047] Furthermore, for example, if the color temperature is gradually changed from 12,000 K to 3,000 K over the course of a day while maintaining an average color rendering index (Ra) of 90 or more and specific color rendering indices of R9 (red) and R15 (skin color) of 90 or more and keeping the illuminance constant, the mRGC ​​stimulation level at each color temperature can be controlled within a range of 0.2 to 0.3 mW / lm.

[0048] The time table is a set of appropriate color temperatures and mRGC ​​stimulation amounts for each time period, based on the data table. Table 3 shows an example of the time table.

[0049] The memory unit 202 may store a data table that associates sets of color temperatures and mRGC ​​stimulation amounts that satisfy conditions other than the general color rendering index (Ra) ≧ 90 under certain illuminance conditions and the special color rendering indexes R9 (red) and R15 (skin color) ≧ 90 with sets of light emission intensities of the first to fifth LEDs 101 to 105.

[0050] For example, Figure 5 shows a distribution map of color temperatures and mRGC ​​stimulation levels that satisfy the conditions of an average color rendering index (Ra) ≥ 70 and special color rendering indices R9 (red) and R15 (skin color) ≥ 70. Figure 6 shows a distribution map of color temperatures and mRGC ​​stimulation levels that satisfy the conditions of an illuminance of 500 lx, an average color rendering index (Ra) ≥ 80, and special color rendering indices R9 (red) and R15 (skin color) ≥ 80.

[0051] Next, we will explain experiments conducted using the light-emitting device 1. [Experiment 1] The light-emitting conditions of the light-emitting device were changed in an artificial climate chamber that blocked external light, and saliva was collected from 22 subjects (males in their 20s) over three days, and the melatonin concentrations in the collected saliva were measured. The light-emitting conditions were measured using a spectroradiometer CL-500A manufactured by Konica Minolta, and melatonin was analyzed using ELISA from Bulmann.

[0052] The experimental schedule is shown in Figure 7. The subjects entered the laboratory at 10:00 on the first day of the experiment and stayed there for four days. After that, they slept in complete darkness from midnight to 7:00 in the morning, and from the second day onwards they spent their time under either lighting conditions A shown in Table 4-1 or Condition B shown in Table 4-2 below.

[0053]

[0054]

[0055] During the experiment, the subjects lived in the laboratory, except in emergencies, and all meals, toileting, and showering were provided at regular intervals at 8:00, 12:00, and 18:00. Drinking water was allowed, but snacking was prohibited.

[0056] Saliva samples were collected every hour from 6:00 PM until midnight.

[0057] During the experiment, subjects were free to spend their time as they wished, except during data collection times. However, excessive exercise and naps were prohibited as they would affect the results. During their free time, they were allowed to read books and write reports, and the use of computer displays and smartphones was permitted between 10:00 a.m. and 4:30 p.m., with the screen brightness set to low.

[0058] Of the 22 subjects, 3 subjects who had problems with the progress of the experiment were excluded, and data from 19 subjects was used to calculate the overall average melatonin concentration on the third day of the experiment under the light conditions A and B. The results are shown in Table 5 and Figure 8.

[0059]

[0060] In condition A, a constant illuminance was maintained from 7:00 AM to midnight, and the mRGC ​​stimulation level was also maintained at 1.2 mW / lm. In condition B, a constant illuminance was maintained from 7:00 AM to midnight, and the mRGC ​​stimulation level was increased to 1.8 mW / lm at a color temperature of 20,000 K to 12,000 K for 30 minutes from 7:00 AM, and then gradually decreased to 0.6 mW / lm from midday to evening.

[0061] As can be seen from Table 5 and Figure 8, there was no significant difference in the mean melatonin concentration between Condition A and Condition B from 6:00 PM to 11:00 PM. However, at midnight, although not statistically significant, there was a tendency for the melatonin concentration to increase under the light conditions of Condition B compared to the light conditions of Condition A.

[0062] Therefore, the average melatonin concentrations from 18:00 to 19:00, which is the first half of the night, and from 23:00 to 24:00 just before going to bed, were calculated from the values ​​shown in Table 5. The results are shown in Table 6. The difference between the average melatonin concentrations from 18:00 to 19:00 and the average melatonin concentrations from 23:00 to 24:00 is shown in Figure 9. This difference corresponds to the amount of change in melatonin secretion during the night.

[0063]

[0064] A test (paired t-test) was conducted to examine the difference in the population means of two related groups for the change in melatonin secretion from the first half of the night to just before bedtime under the light conditions of Condition A and Condition B. A statistically significant difference was detected between the two groups at a risk level of 5% or less (p=0.015), and a greater increase in secretion was observed from the evening to late at night (just before bedtime) under Condition B compared to Condition A.

[0065] From this, it can be inferred that a phase advance in melatonin secretion behavior from the evening until bedtime, or (and) an increase in the total amount of melatonin secreted during the night, was observed under condition B compared to condition A. Because a phase advance in melatonin secretion behavior and an increase in the total amount of melatonin secreted during the night lead to smoother onset of sleep and the securing of deep sleep, condition B is thought to be an effective control of the light and lighting environment for human health.

[0066] [Experiment 2] In Experiment 2, the lighting conditions of Experiment 1 were changed to a different lighting condition, but in order to reduce the effect of blue light emitted from the screens of mobile devices such as smartphones at night on falling asleep, strong stimulation of the mRGC ​​was added in the evening.

[0067] The light-emitting conditions of the light-emitting device were changed in a room blocked from external light, and saliva was collected from one subject (a man in his 50s) over five days, and the melatonin concentration was measured from the collected saliva. The light-emitting conditions were measured using a Konica Minolta CL-500A spectroradiometer, and melatonin was analyzed using a Bulmann ELISA.

[0068] The experimental schedule is shown in Figure 10. The subjects entered the laboratory at 10:00 on the first day of the experiment and stayed there for five days. Days 1 and 2 were spent under illumination conditions A, day 3 under condition B, and day 4 under condition C. During the experiment, the subjects lived entirely in the laboratory, including eating, toileting, and showering, except in emergencies, and were provided with regular meals at 7:00, 12:00, and 18:00. Saliva samples were collected every hour from 18:00 until midnight.

[0069] During the experiment, participants were free to do as they pleased, but excessive exercise and napping were prohibited as they would have an adverse effect on the results. Computer displays and smartphones were allowed to be used as usual between 8:00 a.m. and 4:00 p.m.

[0070] The participants watched videos every day from 8:00 p.m. to midnight by placing the smartphone 30 to 40 cm from their eyes.

[0071] Table 7 shows the details of the light emission conditions that were set.

[0072] Table 8 shows the results of melatonin concentration in Experiment 2. Also, Figure 11 shows a graph of the change in the total amount of increased melatonin secretion from 9 pm to midnight.

[0073]

[0074] The focus of this investigation was on whether or not using artificial light history prior to bedtime was effective in addressing the problem of melatonin secretion being suppressed by light from mobile device monitors experienced from 8 PM until just before going to bed at midnight, which then affects sleep. Table 9 shows the results of Table 5, which were reorganized using the average melatonin concentration from 6 PM to 8 PM as the base and the total increase in melatonin secretion over the following four hours from 9 PM to midnight.

[0075]

[0076] As shown in Table 9, the total increase in melatonin secretion from 9 p.m. to midnight (total of 9 p.m., 9 p.m., 9 p.m., and 9 p.m.) compared to the average melatonin secretion from 6 p.m. to 8 p.m. was 2.5 pg / 4 hours under condition A, 2.8 pg / 4 hours under condition B, and 3.2 pg / 4 hours under condition C.

[0077] In other words, the total amount of melatonin secreted during the nighttime hours leading up to bedtime was found to increase by approximately 12% under condition B, a biorhythm-adjusted light environment, compared to condition A, a general living light environment, and to increase by approximately 28% under condition C, which added the experience of strong stimulation of mRGCs in the evening to the biorhythm-adjusted light environment.

[0078] In this experiment, we only examined melatonin secretion behavior before going to bed, and did not examine melatonin secretion behavior during sleep. Therefore, it is unclear whether the increase in total melatonin secretion during the nighttime up until going to bed was the result of the light environments under Conditions B and C advancing the onset time of melatonin secretion (phase advance), or the result of an increase in the secretion amount itself (amplitude expansion), or both.

[0079] However, whether it is phase advance, amplitude expansion, or both, from the perspective of human health (inducing and ensuring comfortable sleep), a light environment that provides strong stimulation to mRGCs in the evening is thought to bring about very desirable results, and in particular, the light environment under condition C is thought to have a beneficial effect on human health.

[0080] The present invention is not limited to the above-described embodiment, and appropriate modifications and additions can be made.

[0081] For example, Fig. 12 shows a modified example of a light emitting device. The light emitting device includes a rectangular light guide plate 401 and a pair of rod-shaped light emitting units 10 arranged on the left and right sides of the light guide plate 401. Note that the light emission control unit is not shown in Fig. 8. In this configuration, light emitted from a light emitter (not shown) included in the light emitting unit 10 is diffused within the light guide plate 401, and can be emitted as uniform light from the surface of the light guide plate 401.

[0082] Alternatively, as shown in FIG. 13 , the light-emitting unit 10 of the light-emitting device may be disposed in three locations: above, on the left, and right sides of a rectangular mirror 402. The light-emitting control unit is also omitted from FIG. 13 . For example, a lighting environment in front of the mirror can be realized in which the light emitted from the light-emitting unit 10 has a color temperature of 12,000 K, an illuminance of 500 lx or more, an average color rendering index (Ra) of 90 or more, special color rendering indices R9 (red) and R15 (skin color) of 90 or more, and an mRGC ​​stimulation level of 1.8 mW / lm (Melanopic ELR) or more. In other words, makeup can be applied in a lighting environment with high color rendering properties, improving the ease of makeup application and the beauty of the finished look.

[0083] It is generally said that the average time spent putting on makeup in front of a mirror is about 15 to 30 minutes. By using the mirror 402, for example, 30 minutes in the morning can be spent putting on makeup in a light environment with high levels of stimulation to the mRGC, which promotes the secretion of serotonin during the day and helps regulate biological rhythms.

[0084] Furthermore, the light-emitting device according to the present invention is suitable as a light-emitting device for use in patient rooms and living spaces in medical facilities and nursing homes, but may also be used as a light-emitting device for illuminating the interior of offices, schools, ordinary homes, etc. Furthermore, while the above embodiment has described a case where a light-emitting device is used to adjust human biological rhythms, by appropriately selecting and controlling the spectral sensitivity distribution of the light receiver, the light-emitting device may also be used as a lighting device that reduces its effects on the biological rhythms and behavior of animals other than humans, birds, reptiles, and insects, as well as on the germination, growth, and photosynthesis of plants.

[0085] In the above embodiment, the wide-light emitting body is configured from three types of light emitting bodies (LEDs 103 to 105), but the number of light emitting bodies configuring the wide-light emitting body may be one, two, or four or more. Also, the first light emitting body and the second light emitting body may each be configured from two or more types of light emitting bodies.

[0086] Furthermore, the above embodiment is merely an example of the present invention, and it is clear that any modifications, additions, deletions, etc. made within the scope of the claims are also encompassed by the present invention.

[0087] Aspects It will be apparent to those skilled in the art that the exemplary embodiments described above are examples of the following aspects.

[0088] (Clause 1) The light emitting device according to clause 1 comprises: a light emitting section including: a first light emitter that emits light having a peak wavelength in a wavelength range of 480 nm to 510 nm and having a wavelength width characteristic of a double-sided half-maximum wavelength width of 20 nm or less; a second light emitter that emits light having a peak wavelength in a wavelength range of 440 nm to 480 nm and having a wavelength width characteristic of a double-sided half-maximum wavelength width of 20 nm or less; and a wide light light emitter that emits light having a peak wavelength in a wavelength range of 450 nm to 700 nm that is different from the peak wavelengths of the light emitted by the first light emitter and the second light emitter, and having a wavelength width characteristic of a half-maximum wavelength width on the long wavelength side of 30 nm or more; and a control section that can independently control the emission intensities of the light emitted by the first light emitter, the second light emitter, and the wide light light emitter.

[0089] (Clause 2) The light emitting device according to clause 2 is the light emitting device according to clause 1, wherein the broad light emitting body includes: a third illuminant that emits light having a peak wavelength in a wavelength range of 450 nm to 470 nm, and having a wavelength width characteristic in which the half-maximum wavelength width on the short wavelength side is 20 nm or less and the half-maximum wavelength width on the long wavelength side is 50 nm or more; a fourth illuminant that emits light having a peak wavelength in a wavelength range of 540 nm to 550 nm, and having a wavelength width characteristic in which the half-maximum wavelength width on the short wavelength side and the long wavelength side is 30 nm or more, respectively; and a fifth illuminant that emits light having a peak wavelength in a wavelength range of 620 nm to 650 nm, and having a wavelength width characteristic in which the half-maximum wavelength width on the short wavelength side is 30 nm or more and the half-maximum wavelength width on the long wavelength side is 40 nm or more; and the control unit is capable of independently controlling the emission intensities of the light emitted by the third to fifth illuminants.

[0090] (Clause 3) The light emitting device according to clause 3 is the light emitting device according to clause 1 or 2, wherein the control unit controls the light emission intensity of the light emitted by the light emitting element so that the color temperature of the light emitted from the light emitting unit is in the range of 2500K to 15000K.

[0091] (Clause 4) The light emitting device according to clause 4 is the light emitting device according to any one of clauses 1 to 3, further comprising: a setting unit that sets the color temperature and mRGC ​​stimulation amount; and a memory unit that stores information indicating the relationship between the color temperature and mRCG stimulation amount of the light emitted by the light emitting unit and the light emission intensity of the light emitted by each of the first light emitter, the second light emitter, and the wide-light light emitter, and the control unit controls the light emission intensity of each light emitter based on the information so that the color temperature and mRCG stimulation amount of the light emitted by the light emitting unit become the color temperature and mRGC ​​stimulation amount set in the setting unit.

[0092] (Clause 5) The light emitting device according to clause 5 is the light emitting device according to clause 4, wherein the information stored in the memory unit includes information in which the light emitting intensity of the light emitter is associated with a plurality of pairs of the same color temperature but different amounts of mRGC ​​stimulation.

[0093] (Clause 6) The light emitting device according to clause 6 is the light emitting device according to clause 4 or 5, wherein the information stored in the memory unit includes information in which the light emitting intensity of the light emitting element is respectively associated with a plurality of pairs having the same mRGC ​​stimulation amount but different color temperatures.

[0094] (Clause 7) A method for operating a light-emitting device according to clause 7 is a method for operating a light-emitting device according to any one of clauses 4 to 6, which emits light at a predetermined color temperature and with a predetermined amount of mRGC ​​stimulation in order to adjust the biological rhythm of a subject, wherein the control unit, based on the information stored in the storage unit, adjusts the emission intensities of the light emitted by the first light-emitting element, the second light-emitting element, and the wide-light light-emitting element so that, during a time period of 60 to 120 minutes from the wake-up time of the subject, the color temperature and the amount of mRGC ​​stimulation of the light emitted by the light-emitting element are greater than the color temperature and the amount of mRGC ​​stimulation of the light emitted by the light-emitting element in other time periods, and adjusts the emission intensities of the light emitted by the first light-emitting element, the second light-emitting element, and the wide-light light-emitting element so that, during a time period of 60 to 120 minutes from the wake-up time of the subject, the color temperature and the amount of mRGC ​​stimulation of the light emitted by the light-emitting element are smaller than the color temperature and the amount of mRGC ​​stimulation of the light emitted by the light-emitting element in other time periods.

[0095] (Item 8) An operating method of a light-emitting device according to item 8 is a method of operating a light-emitting device according to any one of items 4 to 6, which emits light at a predetermined color temperature and amount of mRGC ​​stimulation in order to adjust the biological rhythm of a subject, wherein the control unit, based on the information stored in the storage unit, adjusts the emission intensities of the light emitted by the first light-emitting element, the second light-emitting element, and the wide-light light-emitting element so that, during a time period of 60 to 120 minutes from a wake-up time of the subject, the color temperature and amount of mRGC ​​stimulation of the light emitted by the light-emitting element are greater than the color temperature and amount of mRGC ​​stimulation of the light emitted by the light-emitting element in other time periods, and adjusts the emission intensities of the light emitted by the first light-emitting element, the second light-emitting element, and the wide-light light-emitting element so that, during a time period of 60 to 120 minutes from a time 10 to 12 hours after the wake-up time, the color temperature and amount of mRGC ​​stimulation of the light emitted by the light-emitting element are greater than the color temperature and amount of mRGC ​​stimulation of the light emitted by the light-emitting element in other time periods.

[0096] (Clause 9) A method for operating a light-emitting device according to clause 9 is a method for operating a light-emitting device according to any one of clauses 4 to 6, wherein the control unit controls the light emission intensity of the light emitted by each of the first light-emitting element, the second light-emitting element and the wide-light light-emitting element based on the information stored in the memory unit, while maintaining the color temperature of the light emitted by the light-emitting element within a predetermined range, so as to change the amount of mRGC ​​stimulation of the emitted light.

[0097] REFERENCE SIGNS LIST 1... Light emitting device 10... Light emitting section 101 to 105... LED (light emitter) 11... Housing 12... Board 13... Drive circuit 20... Light emission control section 201... Light emission control circuit 202... Storage section 203... Setting section 204... Wireless communication section 205... Clock circuit 206... External connection terminal 21... Input section 22... Display section 30... Mobile terminal 401... Light guide plate 402... Mirror

Claims

1. a light emitting section including: a first light emitter emitting light having a peak top wavelength in a wavelength range of 480 nm to 510 nm and having a wavelength width characteristic in which the half-maximum wavelength width on both sides is 20 nm or less; a second light emitter emitting light having a peak top wavelength in a wavelength range of 440 nm to 480 nm and having a wavelength width characteristic in which the half-maximum wavelength width on both sides is 20 nm or less; and a wide light emitter emitting light having a peak top wavelength in a wavelength range of 450 nm to 700 nm that is different from both of the peak top wavelengths of the light emitted by the first light emitter and the second light emitter, and having a wavelength width characteristic in which the half-maximum wavelength width on the long wavelength side is 30 nm or more; a control unit capable of independently controlling the emission intensities of the light emitted by the first light emitter, the second light emitter, and the wide light emitter.

2. The broad light emitter is a third light emitter that emits light having a peak top wavelength in a wavelength range of 450 nm to 470 nm, a half-maximum wavelength width on the short wavelength side being 20 nm or less, and a half-maximum wavelength width on the long wavelength side being 50 nm or more; a fourth light emitter that emits light having a peak top wavelength in a wavelength range of 540 nm to 550 nm and a wavelength width characteristic in which the half-maximum wavelength width on the short wavelength side and the half-maximum wavelength width on the long wavelength side are each 30 nm or more; a fifth light emitter that emits light having a peak top wavelength in a wavelength range of 620 nm to 650 nm, a half-maximum wavelength width on the short wavelength side being 30 nm or more, and a half-maximum wavelength width on the long wavelength side being 40 nm or more; Including, 2. The light emitting device according to claim 1, wherein the control unit is capable of independently controlling the emission intensities of the light emitted by the third to fifth light emitters.

3. The light emitting device according to claim 1 , wherein the control unit controls the emission intensity of the light emitted by the light emitter so that the color temperature of the light emitted by the light emitting unit is in the range of 2500K to 15000K.

4. moreover, A setting unit for setting a color temperature and an mRGC ​​stimulation amount; a storage unit in which information indicating a relationship between a color temperature and an mRCG stimulation amount of the light emitted from the light-emitting unit and an emission intensity of the light emitted by each of the first light-emitting body, the second light-emitting body, and the wide-light light-emitting body is stored; Equipped with The light-emitting device according to claim 1 or 2, wherein the control unit controls the light-emitting intensity of each light-emitting element based on the information so that the color temperature and mRCG stimulation amount of the light emitted from the light-emitting unit become the color temperature and mRGC ​​stimulation amount set in the setting unit.

5. The light emitting device according to claim 4 , wherein the information stored in the memory unit includes information in which the light emission intensity of the light emitter is associated with a plurality of pairs having the same color temperature but different mRGC ​​stimulation amounts.

6. The light emitting device according to claim 4 , wherein the information stored in the memory unit includes information in which the light emission intensity of the light emitter is associated with a plurality of pairs having the same mRGC ​​stimulation amount but different color temperatures.

7. 5. A method for operating a light emitting device according to claim 4, comprising emitting light of a predetermined color temperature and mRGC ​​stimulation amount in order to adjust a biological rhythm of a subject, comprising: a control unit, based on information stored in the memory unit, adjusting the light emission intensities of the light emitted by the first light-emitting element, the second light-emitting element, and the wide light light-emitting element so that, during a time period of 60 to 120 minutes from the subject's wake-up time, the color temperature and the mRGC ​​stimulation amount of the light emitted by the light-emitting element are greater than the color temperature and the mRGC ​​stimulation amount of the light emitted by the light-emitting element in other time periods, and adjusting the light emission intensities of the light emitted by the first light-emitting element, the second light-emitting element, and the wide light light-emitting element so that, during a time period of 10 to 12 hours from the wake-up time to the subject's bedtime, the color temperature and the mRGC ​​stimulation amount of the light emitted by the light-emitting element are smaller than the color temperature and the mRGC ​​stimulation amount of the light emitted by the light-emitting element in other time periods.

8. 5. A method for operating a light emitting device according to claim 4, comprising emitting light of a predetermined color temperature and mRGC ​​stimulation amount in order to adjust a biological rhythm of a subject, comprising: a control unit, based on information stored in the memory unit, adjusts the emission intensities of the light emitted by the first light-emitting element, the second light-emitting element, and the wide light light-emitting element so that, during a time period of 60 to 120 minutes from the subject's wake-up time, the color temperature and the mRGC ​​stimulation amount of the light emitted by the light-emitting element are greater than the color temperature and the mRGC ​​stimulation amount of the light emitted by the light-emitting element in other time periods, and adjusts the emission intensities of the light emitted by the first light-emitting element, the second light-emitting element, and the wide light light-emitting element so that, during a time period of 60 to 120 minutes from a time 10 to 12 hours after the subject's wake-up time, the color temperature and the mRGC ​​stimulation amount of the light emitted by the light-emitting element are greater than the color temperature and the mRGC ​​stimulation amount of the light emitted by the light-emitting element in other time periods.

9. A method for operating a light emitting device according to claim 4, comprising the steps of: A method for operating a light-emitting device, in which the control unit controls the light emission intensity of the light emitted by each of the first light-emitting body, the second light-emitting body, and the wide light-emitting body based on the information stored in the memory unit, while maintaining the color temperature of the light emitted by the light-emitting unit within a predetermined range, so as to change the amount of mRGC ​​stimulation of the emitted light.