JP2022035707A - Lighting method - Google Patents

Abstract

To control glare only by a light emitting element, and secure the brightness of a visual target surface while controlling the glare.SOLUTION: In a lighting method according to an embodiment that irradiates with light from a light source unit equipped with at least one type of light emitting element, when the brightness of light emitted from the light source unit is A (cd/m2), in a certain correlated color temperature of a two-dimensional plane in which λ is the wavelength, S (λ) is the spectral emission brightness of the light emitted from the light source, and ipRGC (λ) is an action function, and the ipRGC action amount represented by ipRGC action amount=1000 (cd/m2)/A (cd/m2)×∫S (λ) ipRGC (λ) dλ is used as a parameter, light is emitted from the light source unit such that the ipRGC effect amount of the light source unit is smaller or larger than the ipRGC effect amount of a reference light source.SELECTED DRAWING: Figure 3

Description

Embodiments of the present invention relate to lighting methods.

Conventionally, in a lighting device having a light emitting element, a technique for reducing glare (glare) by combining a bandpass filter that cuts light in a wavelength band having a short wavelength among the light emitted from the light emitting element and the light emitting element. There is.

Japanese Unexamined Patent Publication No. 2014-17144

However, in the conventional technique as described above, although glare is reduced, a part of the light is wasted because a filter that cuts the light is used, so that the illuminance of the visual object surface supplied from the light emitting element is lowered. It ends up.

An object to be solved by the present invention is to provide an illumination method capable of controlling glare only by a light emitting element and ensuring illuminance on a visual object surface while controlling glare.

The illumination method according to the embodiment is an illumination method in which light is emitted from a light source unit provided with at least one type of light emitting element, and the brightness of the light emitted from the light source unit is defined as A (cd / m ² ). In this case, λ is the wavelength, S (λ) is the spectral emission brightness of the light emitted from the light source, and ipRGC (λ) is the function of action, and the amount of action of ipRGC expressed by the following formula is the correlated color temperature and the above. Light from the light source unit so that the ipRGC effect amount of the light source unit is smaller or larger than the ipRGC effect amount of the reference light source at an arbitrary correlated color temperature of the two-dimensional plane using the ipRGC effect amount as a parameter. It is characterized by irradiating.

According to the present invention, the glare can be controlled only by the light emitting element, and the illuminance of the visual object surface can be secured while controlling the glare.

FIG. 1 is a diagram showing an example of a lighting device using the lighting method according to the embodiment. FIG. 2 is a diagram showing an example of a light source unit and a control unit according to an embodiment. FIG. 3 is a diagram showing sensitivity curves of ipRGC and L cones, M cones, and S cones. FIG. 4 is a diagram showing a color matching function for deriving a sensitivity curve of a cone. FIG. 5A is a diagram showing the conditions of this study. FIG. 5B is a diagram showing the relationship between ipRGC and glare obtained in this study. FIG. 6A is a diagram showing a spectral spectrum in the case of a correlated color temperature of 2700 K. FIG. 6B is a diagram showing a spectral spectrum in the case of a correlated color temperature of 2700 K +. FIG. 6C is a diagram showing a spectral spectrum in the case of a correlated color temperature of 8000K. FIG. 6D is a diagram showing a spectral spectrum in the case of a correlated color temperature of 8000K-. FIG. 7 is a diagram showing the relationship between the correlated color temperature and the ipRGC action amount (No. 1). FIG. 8 is a diagram showing the relationship between the correlated color temperature and the ipRGC action amount (No. 2).

The illumination method according to the embodiment described below is an illumination method in which light is emitted from a light source unit provided with at least one type of light emitting element, and the brightness of the light emitted from the light source unit is A (cd / m). In the case of ² ), λ is the wavelength, S (λ) is the spectral emission brightness of the light emitted from the light source, and ipRGC (λ) is the function of action, and the amount of action of ipRGC expressed by the following formula is the correlated color temperature. And, at an arbitrary correlated color temperature of the two-dimensional plane using the ipRGC action amount as a parameter, light is irradiated from the light source unit so that the ipRGC action amount of the light source unit is smaller or larger than the ipRGC action amount of the reference light source. ..

Further, in the lighting method according to the embodiment described below, the light source unit includes at least two types of light emitting elements having different peak wavelengths, and is illuminated by the first lighting method and the first lighting method. It is possible to switch between a second lighting method for irradiating light having the same correlated color temperature as the light and the same as the ipRGC working amount of the reference light source.

Further, in the lighting method according to the embodiment described below, the glare is different between the light illuminated by the first lighting method and the light illuminated by the second lighting method.

Further, in the lighting method according to the embodiment described below, (correlated color temperature, ipRGC working amount) = (2700, 0.6), ( It irradiates light in the area surrounded by 2700, 1.5), (8000, 1.5), (8000, 0.6).

Further, in the illumination method according to the embodiment described below, the light source unit includes a first light emitting element having a peak wavelength of 430 ± 10 nm, a second light emitting element having a peak wavelength of 500 ± 10 nm, and a peak wavelength of 570. A third light emitting element having a peak wavelength of ± 10 nm and a fourth light emitting element having a peak wavelength of 630 ± 10 nm are provided.

Hereinafter, the lighting method according to the embodiment will be described in detail. The present invention is not limited to the embodiments shown below.

A lighting device 10 using the lighting method according to the embodiment will be described with reference to FIGS. 1 and 2. FIG. 1 is a diagram (schematic perspective view) showing an example of a lighting device 10 using the lighting method according to the embodiment. FIG. 2 is a diagram (schematic plan view) showing an example of the light source unit 20 and the control unit 30 in the embodiment.

As shown in FIG. 1, the lighting device 10 includes a main body 11, a cover 12, a light source unit 20, and a control unit 30 (see FIG. 2). The lighting device 10 is, for example, a so-called base light that is attached to the ceiling surface with the cover 12 facing downward. The lighting device 10 is not limited to the ceiling surface, and may be attached to any attachment target such as a wall surface. Further, a plurality of lighting devices 10 may be connected. Further, the lighting device 10 is not limited to the base light, and any form of the lighting device can be adopted.

The main body 11 is a mounting portion mounted on the ceiling surface, and is also a supporting portion that supports the cover 12. Inside the main body 11, a light source unit 20, a power supply unit (not shown), a control unit 30 described later, and the like are housed. The cover 12 is a cover that covers the light emitting surface of the lighting device 10 and diffuses the light emitted from the light emitting element 21 described later.

The light source unit 20 is driven by the electric power supplied from the power supply unit and emits light downward. The light source unit 20 includes one type of light emitting element 21 or a plurality of light emitting elements 21 having different peak wavelengths. Preferably, the light source unit 20 includes two or more types of light emitting elements 21 having different peak wavelengths. More preferably, the light source unit 20 includes four or more types of light emitting elements 21 having different peak wavelengths.

The light source unit 20 shown in FIG. 2 shows an example including four types of light emitting elements 21 (first to fourth light emitting elements 21a to 21d). The light emitting element 21 is, for example, an LED (Light Emitting Diode). As the LED, an InGaN-based LED, which is a gallium nitride-based LED, can be adopted. The light emitting element 21 is electrically connected to the control unit 30, respectively. When a plurality of types of light emitting elements 21 having different peak wavelengths are provided, the light emitting element 21 is electrically connected to the control unit 30 so that the peak wavelength of the light emitting element 21 can be controlled independently.

The first light emitting element 21a is, for example, a light emitting element having a peak wavelength of about 630 nm and having a red emission color, and one or a plurality of the first light emitting elements 21a are arranged in the light source unit 20. The second light emitting element 21b is, for example, a light emitting element having a peak wavelength of about 570 nm and having a yellow emission color, and one or a plurality of the second light emitting elements 21b are arranged in the light source unit 20. The third light emitting element 21c is, for example, a light emitting element having a peak wavelength of 500 nm and having a blue-green emission color, and one or a plurality of the third light emitting elements 21c are arranged in the light source unit 20. The fourth light emitting element 21d is, for example, a light emitting element having a peak wavelength of about 430 nm and having a blue emission color, and one or a plurality of the fourth light emitting elements 21d are arranged in the light source unit 20. The first to fourth light emitting elements 21a to 21d are not limited to the arrangement in which they are adjacent to each other as shown in FIG. 2, and are arranged in an arbitrary arrangement such as a staggered arrangement.

The control unit 30 is a controller that controls the lighting device 10. The control unit 30 can be implemented by a processor such as a CPU (Central Processing Unit) or an MPU (Micro Processing Unit), for example. Alternatively, the control unit 30 may be implemented by an integrated circuit such as an FPGA (Field Programmable Gate Array) or an ASIC (Application Specific Integrated Circuit).

Further, the control unit 30 includes a semiconductor memory element such as a RAM (Random Access Memory) or a flash memory, or a storage device such as a hard disk or an optical disk.

Further, the control unit 30 controls the output of the light source unit 20. That is, the control unit 30 controls the output of the light emitting element 21 respectively. Therefore, the control unit 30 can adjust the emission peak intensity of the light emitting element 21. When the light source unit 20 includes a plurality of light emitting elements 21 having different peak wavelengths, it is possible to adjust the emission peak intensity for each of the light emitting elements 21 having different peak wavelengths.

By the way, among the light emitted from the light emitting element 21, glare is removed by removing light in a short wavelength band called blue light, which is light having a wavelength of 500 nm or less, which is said to cause glare. Is required to be reduced. In this case, for example, when a bandpass filter or the like that cuts light in a wavelength band having a short wavelength is used, the illuminance of the visual object surface supplied from the light emitting element 21 decreases. Therefore, there has been a need for a method that can reduce glare without reducing the illuminance of the visual target surface.

At present, it has become clear that there is a high possibility that an endogenous photosensitive retinal ganglion cell (hereinafter referred to as ipRGC), which is a third photoreceptor, is involved as a photoreceptor that affects glare. Therefore, as a method of reducing glare (glare) without reducing the illuminance of the visual target surface, it was examined to adjust the amount of action of ipRGC by a light source.

Hereinafter, this study will be described with reference to FIGS. 3 to 8. FIG. 3 is a diagram showing sensitivity curves of ipRGC and L cones, M cones, and S cones. FIG. 4 is a diagram showing a color matching function for deriving a sensitivity curve of a cone. Although the color matching function here is calculated using the function of CIE2006, the function of CIE1931 may be used.

FIG. 5A is a diagram showing the conditions of this study, and FIG. 5B is a diagram showing the relationship between ipRGC and glare obtained in this study. FIG. 6A is a diagram showing a spectral spectrum in the case of a correlated color temperature of 2700K used in this study, FIG. 6B is a diagram showing a spectral spectrum in the case of a correlated color temperature of 2700K + used in this study, and FIG. 6C is a diagram showing. FIG. 6D is a diagram showing a spectral spectrum in the case of a correlated color temperature of 8000K used in this study, and FIG. 6D is a diagram showing a spectral spectrum in the case of a correlated color temperature of 8000K − used in this study.

FIG. 7 is a diagram showing the relationship between the correlated color temperature and the ipRGC action amount (No. 1). FIG. 8 is a diagram showing the relationship between the correlated color temperature and the ipRGC action amount (No. 2).

As shown in FIG. 3, the sensitivity (also referred to as luminosically) curve of ipRGC and the cones (L cone, M cone, S cone) of photoreceptor cells in a bright place (for example, about 1000 cd / m ² ). ), The peak wavelength of the sensitivity curve of ipRGC is different from the peak wavelength of the sensitivity curve of the cone of the photoreceptor cell. The peak wavelength of the sensitivity curve of the L cone is about 570 nm, the peak wavelength of the sensitivity curve of the M cone is about 543 nm, and the peak wavelength of the sensitivity curve of the S cone is about 442 nm. The peak wavelength is about 490 nm. The amount of action of ipRGC and each cone can be derived using the sensitivity curve shown in FIG.

The ipRGC action amount is obtained by integrating the relative value of the luminous efficiency ipRGC (λ) of the ipRGC in the wavelength range of 380 to 780 nm and the spectral radiance S (λ) of the light source and integrating at the wavelength λ. The quantity is calculated (Equation 1). The unit of the spectral radiance S (λ) is W / m ² / sr.

The higher the brightness A of the light source, the larger the ipRGC basic action amount obtained in Equation 1 can be obtained. Therefore, the ipRGC basic action amount obtained in Equation 1 is normalized to be the ipRGC basic action amount (also referred to as reaction amount). Used as. Specifically, in this study, the ipRGC basic action amount obtained in Equation 1 is converted into a numerical value per 1000 cd / m ² and defined as the ipRGC action amount (Equation 2).

Therefore, the ipRGC action amount can be obtained by the following mathematical formula (Equation 3).

For example, in the case of the ipRGC basic action amount calculated using a light source of 100 cd / m ² , the value obtained by multiplying the ipRGC basic action amount by 10 is the ipRGC action amount, which is the ipRGC basic action amount calculated using a light source of 10000 cd / m ² . In the case of the action amount, the value obtained by multiplying the ipRGC basic action amount by 0.1 is the ipRGC action amount.

The ipRGC action amount may be defined by a value converted into an arbitrary numerical value instead of a value obtained by converting the ipRGC basic action amount into a numerical value per 1000 cd / m ² . In that case, in Equation 2, the ipRGC action amount is derived by a mathematical formula in which the portion of 1000 (cd / m ² ) is replaced with an arbitrary numerical value. In addition, the ipRGC action amount does not necessarily have to be normalized based on the brightness (cd / m ² ), and it is not always necessary to normalize the light in an international unit system such as luminous flux (lm), illuminance (lp), and luminous intensity (cd). It may be normalized based on the appropriate unit.

From here, the contents of this study will be explained in more detail. In order to confirm the effect of the ipRGC action amount, it was examined to adjust the ipRGC action amount without changing the brightness, the action amount of the L cone, the action amount of the M cone, and the action amount of the S cone. If the glare can be controlled by adjusting the ipRGC action amount, it is possible to secure the illuminance of the visual target surface while reducing the glare. Since the illuminance of the visual target surface is calculated using the color matching function (color matching function of CIE2006) as shown in FIG. 4, which is closely related to the sensitivity curve of the cone, it is independent of the ipRGC action amount. It is possible to calculate. As the color matching function, the function of CIE 1931 may be used.

In this study, a light emitting element having a peak wavelength of about 430 nm in the spectral spectrum, a light emitting element having a peak wavelength of about 500 nm in the spectral spectrum, a light emitting element having a peak wavelength of about 570 nm in the spectral spectrum, and a peak wavelength of the spectral spectrum are used. A light source using a light emitting element having a wavelength of about 630 nm is used.

Then, as shown in FIG. 5A, the two light sources, 2700K and 2700K +, which have the same amount of action of the L cone, the amount of action of the M cone, and the amount of action of the S cone, but different from each other, feel dazzling. Which of the two light sources, 8000K and 8000K-, which has the same amount of action of the L cone, the amount of action of the M cone, and the amount of action of the S cone but different ipRGC action amount, feels dazzling? An experiment was conducted.

Although the notation of luminance is omitted in FIG. 5A, 2700K, 2700K +, 8000K, and 8000K− all have the same luminance. Then, as shown in FIG. 5A, in the case of the correlated color temperature of 2700K, (L action amount, M action amount, S action amount, ipRGC action amount) = (1.6, 1.1, 0.2, 0. 6), and in the case of a correlated color temperature of 2700 K +, (L action amount, M action amount, S action amount, ipRGC action amount) = (1.6, 1.1, 0.2, 1.5). .. Further, as shown in FIG. 5A, in the case of the correlated color temperature of 8000K, (L action amount, M action amount, S action amount, ipRGC action amount) = (1.5, 1.3, 1.0, 1. 5), and in the case of a correlated color temperature of 8000K-, (L action amount, M action amount, S action amount, ipRGC action amount) = (1.5, 1.3, 1.0, 0.6). be.

2700K is a light source having a correlated color temperature of 2700K and adjusted so as to approach the same ipRGC working amount as the reference light source of 2700K. 2700K + is a light source adjusted so that the action amount of the L cone, the action amount of the M cone, and the action amount of the S cone are the same as those of 2700K, and the ipRGC action amount is equivalent to 8000K described later. The 2700K spectral spectrum is shown in FIG. 6A, and the 2700K + spectral spectrum is shown in FIG. 6B.

8000K is a light source having a correlated color temperature of 8000K and adjusted so as to approach the same ipRGC working amount as the reference light source of 8000K. 8000K- is a light source adjusted so that the action amount of the L cone, the action amount of the M cone, and the action amount of the S cone are the same as those of 8000K, and the ipRGC action amount is equivalent to the above-mentioned 2700K. The spectroscopic spectrum of 8000K is shown in FIG. 6C, and the spectroscopic spectrum of 8000K- is shown in FIG. 6D.

The results of the subject experiment are shown in FIG. 5B. It was found that in the case of the correlated color temperature of 2700K (2700K +) in which the ipRGC action amount was controlled, the glare equivalent to the correlated color temperature of 8000K was felt. Further, it was found that in the case of the correlated color temperature of 8000K (8000K-) in which the ipRGC action amount was controlled, the glare equivalent to the correlated color temperature of 2700K was felt. That is, the ipRGC action amount is applied to the light having a correlated color temperature of 8000 K, which is generally high glare (glare) light, and the light having a correlated color temperature of 2700 K, which is generally low glare (not dazzling) light. By controlling it, it is possible to produce glare (not dazzling) light equivalent to 2700K with a correlated color temperature of 8000K, or to produce glare (glare) light equivalent to 8000K with a correlated color temperature of 2700K.

In this study, in order to confirm the effect of ipRGC action amount, we compared two spectra in which the action amount of L cone, the action amount of M cone, and the action amount of S cone are the same. Even under conditions where the amount of action of the L cone, the amount of action of the M cone, and the amount of action of the S cone are not the same, it is possible to produce the above-mentioned light by controlling the amount of action of ipRGC.

In addition, the areas confirmed in this study are shown in FIG. FIG. 7 is a two-dimensional plane provided with a correlated color temperature [K] on the horizontal axis and an ipRGC action amount per 1000 cd / m ² on the vertical axis, and (correlated color temperature, ipRGC action amount) = (2700, 0). It is an area surrounded by four points (6), (2700, 1.5), (8000, 1.5), and (8000, 0.6).

For example, as light 1, (correlated color temperature, ipRGC action amount per 1000 cd / m ² ) = (K1, α), and as light 2, (correlation color temperature, ipRGC action amount per 1000 cd / m ² ) = (K2). β), is created. Note that K1 and K2 are arbitrary points within the range of the correlated color temperature shown in FIG. 7. At this time, when α> β, the light 1 feels dazzling.

On the contrary, when α <β, light 2 feels dazzling. In these cases, it is possible to sense the difference in glare depending on the magnitude of α and β even under the condition of K1 ≠ K2, but the difference in glare is more noticeable under the condition of K1 = K. It becomes possible.

The control of how the glare is perceived by adjusting the ipRGC action amount can be applied not only to the relationship between 2700K and 8000K but also to any correlated color temperature. FIG. 8 shows the amount of ipRGC action per 1000 cd / m ² in the reference light source for each correlated color temperature. The reference light source is blackbody radiation or CIE daylight.

At a reference light source of 1600K, the ipRGC amount of action is about 0.25. At a reference light source of 2000K, the ipRGC action amount is about 0.39. At a reference light source of 2700K, the ipRGC amount of action is about 0.61. At a reference light source of 3000 K, the ipRGC action amount is about 0.70. At a reference light source of 4000 K, the ipRGC action amount is about 0.94. At a reference light source of 5000 K, the ipRGC action amount is about 1.12. At a reference light source of 6500K, the ipRGC amount of action is about 1.33. At a reference light source of 8000K, the ipRGC amount of action is about 1.47. At a reference light source of 10000K, the ipRGC amount of action is about 1.60. At a reference light source of 25000K, the ipRGC amount of action is about 1.93.

In addition, when FIG. 8 is simplified, it is possible to classify into two types of inclinations, one is between 1600K and more and 10000K or less, and the other is between 10000K and more and 25000K or less. The slope between 1600K and 10000K is the slope shown in the following formula (Equation 4), and the slope between 1600K and above and 25,000K or less is the slope shown in the following formula (Equation 5).

Then, at a certain correlated color temperature, a light source having an ipRGC action amount lower than that of the reference light source shown in FIG. 8 is a light source that is less dazzling than the reference light source. Further, a light source having an ipRGC action amount larger than that of the reference light source shown in FIG. 8 is a dazzling light source than the reference light source.

Therefore, in a module provided with two or more types of light emitting elements 21 having different peak wavelengths, an ipRGC working amount equivalent to a reference light source having an arbitrary correlated color temperature (for example, a value of about ± 20% centered on the value shown in FIG. 8). ), And the corresponding color temperature equivalent to the correlated color temperature illuminated by this method (for example, the variation of the correlated color temperature is ± 500K) and the ipRGC working amount is reduced from the ipRGC working amount equivalent to the reference light source. Alternatively, if the method of illuminating the increased light can be switched, it becomes possible to switch between two lights having different glare depending on the application, and the versatility is high. In this case, regarding the value for reducing or increasing the ipRGC action amount from the ipRGC action amount equivalent to the reference light source, at the correlated color temperature of 1600 K or more and 10,000 K or less, the width of the ipRGC action amount corresponding to the reference light source and the variation of the correlated color temperature In consideration of the above, it is preferable to reduce or increase the ipRGC action amount by 0.1 or more. Further, at the correlated color temperature of more than 10,000 K and 25,000 K or less, it is preferable to reduce or increase the ipRGC action amount by 0.015 or more in consideration of the width of the ipRGC action amount corresponding to the reference light source and the variation of the correlation color temperature.

In the above-described embodiment, the ipRGC and the correlated color temperature have been described as parameters, but in another example, the color rendering property may be used as a parameter. In other words, how to change the correlated color temperature while fixing the ipRGC (the glare does not change but the correlated color temperature changes), or change the ipRGC while keeping the correlated color temperature fixed (the correlated color temperature does not change but the glare). In addition to the usage (the color temperature changes), it is also possible to change the color playability while fixing the ipRGC and the correlated color temperature (the correlated color temperature and the glare do not change, but the color playability changes).

For example, by using four types of light emitting devices having peak wavelengths of 430 nm, 500 nm, 570 nm, and 630 nm, various color rendering properties (Ra) can be realized under the conditions of 2700 K and fixed to any ipRGC. If it is desired to widen the range in which the color rendering property can be changed in the direction of increasing the color rendering property (Ra) in this state, for example, a light emitting element having a peak at 650 nm or more may be added as the fifth light emitting element. ..

Further, in this study, four types of light emitting devices having different peak wavelengths of 430 nm, 500 nm, 570 nm, and 630 nm are used. The light emitting element with a peak wavelength of 430 nm matches the sensitivity curve of the S cone (peak wavelength is about 442 nm), and the light emitting element with a peak wavelength of 500 nm matches the sensitivity curve of ipRGC (peak wavelength is about 490 nm). The light emitting element with a peak wavelength of 570 nm matches the sensitivity curve of the M cone (peak wavelength is about 543 nm), and the light emitting element with a peak wavelength of 630 nm matches the sensitivity curve of the L cone (peak wavelength is about 570 nm). Therefore, the amount of action of each cone is selected so that it can be adjusted. However, none of them match the peak wavelength of each sensitivity curve. This is because a light source with a variable correlated color temperature is assumed, and in a module with a variable correlated color temperature equipped with four types of light emitting elements, if the above configuration is used, a wide range of colors can be created in the chromaticity coordinates. It is possible to adjust the amount of ipRGC action so as to be possible and not affect the color gamut. Considering the variation in emission wavelength, four types of emission elements having peak wavelengths of 430 ± 10 nm, 500 ± 10 nm, 570 ± 10 nm, and 630 ± 10 nm may be selected.

Of the emission peak wavelength values, 430 nm tends to contribute to the correlated color temperature, 500 nm to the ipRGC action amount, 570 nm to illuminance and luminance, and 630 nm to contribute to color rendering.

As described above, the illumination method according to the embodiment is an illumination method in which light is emitted from a light source unit 20 provided with at least one type of light emitting element, and the brightness of the light emitted from the light source unit 20 is A. When (cd / m ² ) is set, λ is the wavelength, S (λ) is the spectral emission brightness of the light emitted from the light source unit 20, and ipRGC (λ) is the function of action, and the amount of ipRGC action expressed by the following formula. In any correlated color temperature of the two-dimensional plane with the correlated color temperature and the ipRGC working amount as parameters, the light source unit so that the ipRGC working amount of the light source unit is smaller or larger than the ipRGC working amount of the reference light source. Light is emitted from 20.

In this way, the wavelength λ corresponding to the relative visual sensitivity ipRGC (λ) of the ipRGC can be controlled independently of the correlated color temperature. Therefore, glare can be controlled only by the light emitting element 21, and for example, the glare of the visual target surface can be reduced only by the light emitting element 21 without using a bandpass filter that cuts a short wavelength band. The illuminance can be secured.

Further, in the lighting method according to the embodiment, the light source unit 20 includes at least two types of light emitting elements 21 having different peak wavelengths, and the above-mentioned lighting method (first lighting method) and the first lighting method. It is possible to switch between a second illumination method for irradiating light having the same correlated color temperature as the light illuminated by the light source and the same as the ipRGC working amount of the reference light source. Therefore, it is possible to switch between two lights with different glare depending on the application.

Further, in the lighting method according to the embodiment, the glare is different between the light illuminated by the first lighting method and the light illuminated by the second lighting method. Therefore, by switching between two lights with different glare according to the application, the versatility is increased.

Further, in the lighting method according to the embodiment, (correlated color temperature, ipRGC working amount) = (2700, 0.6), (2700, 1) in a two-dimensional plane having the correlated color temperature and the ipRGC working amount as parameters. .5) Irradiate the light in the area surrounded by (8000, 1.5), (8000, 0.6). Therefore, it is possible to produce glare (not dazzling) light equivalent to 2700K with a correlated color temperature of 8000K, or to produce glare (glare) light equivalent to 8000K with a correlated color temperature of 2700K.

Further, in the illumination method according to the embodiment, the light source unit 20 has a first light emitting element 21a having a peak wavelength of 430 ± 10 nm, a second light emitting element 21b having a peak wavelength of 500 ± 10 nm, and a peak wavelength of 570 ±. A third light emitting element 21c having a peak wavelength of 10 nm and a fourth light emitting element 21d having a peak wavelength of 630 ± 10 nm are provided. Since the wavelength λ corresponding to the relative luminosity ipRGC (λ) of the ipRGC can be controlled independently of the correlated color temperature, glare can be controlled only by the light emitting element 21, for example, a wavelength having a short wavelength. It is possible to secure the illuminance of the visual target surface while reducing the glare only by the light emitting element 21 without using a band pass filter or the like that cuts the band. Although the above four peak wavelengths are used here, the peak wavelength of the third light emitting element 21c may be changed to 540 ± 10 nm when chromatic light is realized.

In the above-described embodiment, the LED is used as the light emitting element 21, but the light emitting element 21 is not limited to this, and for example, a phosphor may be adopted as the light emitting element 21.

Further, in the above-described embodiment, the lighting method is applied to the lighting device 10, but the lighting method is not limited to this, and for example, such a lighting method can be applied to the backlight of the display device or the like. For example, by applying it to the backlight of a display device, glare (glare) such as night mode can be controlled.

Although some embodiments of the present invention have been described, these embodiments are presented as examples and are not intended to limit the scope of the invention. These embodiments can be implemented in various other embodiments, and various omissions, replacements, and changes can be made without departing from the gist of the invention. These embodiments and variations thereof are included in the scope of the invention described in the claims and the equivalent scope thereof, as are included in the scope and gist of the invention.

10 Lighting device 11 Main body 12 Cover 20 Light source unit 21 Light emitting element 21a First light emitting element 21b Second light emitting element 21c Third light emitting element 21d Fourth light emitting element 30 Control unit

Claims (5)

A lighting method for irradiating light from a light source unit provided with at least one type of light emitting element.
When the brightness of the light emitted from the light source unit is A (cd / m ² ), λ is the wavelength, S (λ) is the spectral emission brightness of the light emitted from the light source unit, and ipRGC (λ) is applied. As a function, the ipRGC action amount represented by the following formula is used in the light source unit from the ipRGC action amount of the reference light source at any correlated color temperature on the two-dimensional plane using the correlation color temperature and the ipRGC action amount as parameters. A lighting method characterized by irradiating light from the light source unit so that the ipRGC working amount is smaller or larger.

The light source unit includes at least two or more types of light emitting elements having different peak wavelengths.
The first illumination method according to claim 1 and the second illumination method for irradiating light having a correlation color temperature equivalent to that of the light illuminated by the first illumination method and equivalent to the ipRGC working amount of the reference light source. A lighting method characterized by being able to switch between. The lighting method according to claim 2, wherein the light illuminated by the first lighting method and the light illuminated by the second lighting method have different glare. In a two-dimensional plane using the correlated color temperature and the ipRGC working amount as parameters, (correlated color temperature, ipRGC working amount) = (2700, 0.6), (2700, 1.5), (8000, 1.5). ), The lighting method according to any one of claims 1 to 3, wherein the light is irradiated in the area surrounded by (8000, 0.6). The light source unit has a first light emitting element having a peak wavelength of 430 ± 10 nm, a second light emitting element having a peak wavelength of 500 ± 10 nm, a third light emitting element having a peak wavelength of 570 ± 10 nm, and a peak wavelength. The lighting method according to any one of claims 1 to 4, further comprising a fourth light emitting element having a wavelength of 630 ± 10 nm.

Images