JP2020167138A - Illumination device, illumination system and illumination method - Google Patents

Abstract

To provide an illumination device with which a state of an object may be seen properly.SOLUTION: Disclosed is an illumination device according to an example of an embodiment irradiating an object that has a first wavelength range having a relatively high spectral reflectance with respect to a wavelength and has a fluctuating spectral reflectance with respect to a wavelength over time. The illumination device is provided with a light source having a first spectrum. The first spectrum has a first peak in a second wavelength range within a first wavelength range, in which the amount of decrease in spectral reflectance over time in the object is relatively large. A width at a half-value of the first peak is narrower than a width of the second wavelength range.SELECTED DRAWING: Figure 2

Description

Embodiments of the present invention relate to lighting devices, lighting systems and lighting methods.

Conventionally, a lighting device capable of making an object look vivid has been known. Such a lighting device is used in a supermarket, for example, and by irradiating the food displayed on the food display shelf with light from the lighting device, it is possible to display the food while making it look vivid. ..

However, some objects that look vivid, such as fresh foods and paints, deteriorate in quality over time. When such an object is irradiated with light from a conventional vivid lighting device, the deteriorated object is also shown vividly, so that it is difficult to visually recognize that the quality has deteriorated. Therefore, for example, there is a possibility that a problem may occur in which products having deteriorated quality are lined up in the store as they are.

Japanese Unexamined Patent Publication No. 2013-127855 JP-A-2015-41633

An object to be solved by the present invention is to provide a lighting device capable of appropriately showing the state of an object.

The lighting device according to an example of the embodiment is a lighting device that has a first wavelength region having a relatively high spectral reflectance with respect to a wavelength and irradiates an object whose spectral reflectance with respect to a wavelength fluctuates with time. The illuminator comprises a light source having a first spectrum. The first spectrum has a first peak in a second wavelength region, which is a first wavelength region in which the amount of decrease in spectral reflectance over time in the object is relatively large. The full width at half maximum at the first peak is narrower than the width of the second wavelength region.

According to the embodiment, it can be expected to provide a lighting device capable of appropriately showing the state of the object.

It is a figure which shows the lighting apparatus which shows one Embodiment. It is a figure which shows the light source device provided in the lighting device which shows one Embodiment. (A) This is an example of a graph showing the spectral reflectance of beef as an object. (B) This is an example of a graph showing the difference in spectral reflectance for each unit time of beef as an object. (A) It is a graph which showed an example of the spectral distribution of the lighting apparatus which shows one Embodiment. (B) It is a graph which showed the spectral distribution of the conventional lighting apparatus. This is an example of the result of simulating the fluctuation of the L ^* value when irradiating beef as an object with each light source. (A) This is an example of a diagram simulating a change in chromaticity for each unit time when beef as an object is irradiated with a conventional lighting device and reference light. (B) This is an example of a diagram simulating a change in chromaticity for each unit time when beef as an object is irradiated with a lighting device and a reference light. It is a figure which shows the lighting apparatus as a 1st modification. It is a figure which shows the lighting apparatus as a 2nd modification. The figure shows the results of simulating the fluctuations of the L ^* value, a ^* value, and b ^* value when beef is irradiated with the lighting device, the reference light, and the conventional lighting device in the L ^* a ^* b ^* three-dimensional coordinate space. is there.

Hereinafter, one embodiment will be described with reference to the drawings. In the following, the wavelength will be described in the visible light region. That is, light having a wavelength in the range of 380 nm to 780 nm, which is visible light that can be perceived by the human eye, will be described.

FIG. 1 shows a lighting device 1 that irradiates an object. The lighting device 1 includes a light source device 2 and a lighting control unit 3 that lights and controls the light source device 2. It is assumed that the reflection state of the object here changes with time. That is, as time passes, for example, the object whose reflectance fluctuates due to a change in composition, or the object whose light reflection direction and diffuse reflection ratio fluctuate due to a change in surface state are targeted. Further, the object in the present embodiment is preferably such that the reflection state fluctuates within several days from the initial state, for example.

FIG. 2 shows the light source device 2. The light source device 2 includes a first light source 10, a second light source 20, and a third light source 30. The first light source 10, the second light source 20, and the third light source 30 are each formed by one light source or a plurality of light sources. Further, as shown in FIG. 2, the present invention is not limited to the form in which the first light source 10, the second light source 20, and the third light source 30 are individually arranged in one row. For example, the light sources may be arranged in a staggered arrangement in which the light sources are scattered, or the second light source 20 and the third light source 30 may be arranged so as to cover the first light source 10.

The first light source 10 is a blue light source having a peak wavelength of 450 nm to 490 nm. The first light source 10 is a light source having a half width of 10 nm to 40 nm, for example, about 19 nm. The second light source 20 is a red light source having a peak wavelength of 610 nm to 650 nm. The second light source 20 has a half width of 10 nm to 40 nm, for example, about 28 nm. The third light source 30 is a white light source, for example, a white light source having a color temperature of 3000 K and a color deviation of −0.030. The third light source 30 is, for example, a light source having at least three colors of red, green, and blue, a light source having at least three colors of red, yellow, and blue, or yellow due to an excitation light source. It may be a light source in which at least one of a phosphor, a green phosphor, and a red phosphor is excited. Further, it is desirable that the light source here is a solid-state light source such as an LED, LD, or OLED.

The lighting control unit 3 includes a power supply device 40 for driving the light source device 2. The power supply device 40 may be composed of one, two or three power supplies. When the power supply device 40 is composed of one power source, for example, the first light source 10, the second light source 20, and the third light source 30 are connected in series or in parallel, and all of them are turned on together. When the power supply device 40 is composed of two power sources (power sources 40A and 40B), for example, the first light source 10 and the third light source 30 are connected in series or in parallel and lit by the power source 40A, and the second light source is lit. 20 is turned on by the power source 40B. Alternatively, the first light source 10 may be lit by the power supply 40A, and the second light source 20 and the third light source 30 may be directly or in parallel and lit by the power supply 40B. When the power supply device 40 is composed of three power sources (power sources 40A, 40B, 40C), for example, the first light source 10 is lit by the power source 40A, the second light source 20 is lit by the power source 40B, and so on. The third light source 30 is turned on by the power supply 40C.

Further, the lighting control unit 3 may have a control unit 50. As the control function performed by the control unit 50, for example, the light source device 2 may be dimmed to change the light emission intensity, or the light source device 2 may be toned to change the color temperature of the light. Alternatively, the light source device 2 may perform an operation of changing the emission intensity from a specific light source. As an operation of changing a specific light source, for example, the emission intensity of the first light source 10 is increased to enhance the blue spectrum, or the emission intensity of the second light source 20 is increased to enhance the red spectrum. Further, the controller unit 50 may be arranged separately from the power supply device 40, may be arranged in connection with the power supply device 40, or may be integrally formed with the power supply device 40. ..

For example, when performing the dimming operation of the lighting device 1, if the power supply device 40 is composed of one power supply, the dimming operation can only be performed collectively as a whole, but there are two power supply devices 40 or When it is composed of three power supplies, it is possible to perform dimming operation in small units for each power supply device. In particular, when the power supply device 40 is composed of three power sources, the first light source 10, the second light source 20, and the third light source 30 can be individually dimmed. Of course, even when the power supply device 40 is composed of three power supplies, the dimming operation may be performed as a whole.

The control signal for operating the control function may be input by operating a button or a knob provided on the lighting device 1, for example, or a control signal may be input from the outside. When a control signal is input from the outside, as shown in FIG. 1, a receiving unit 60 is provided in the lighting device 1, and the receiving unit 60 receives the control signal. After that, the control signal is passed to the lighting control unit 3, and the output of the power supply device 40 is changed according to the control signal. When a control signal is input from the outside, for example, an optical signal such as infrared rays or visible light may be input from a remote controller, or a signal may be input from a communication device by wired or wireless communication.

Next, the movement when irradiating the object with the light emitted from the lighting device 1 will be described. In the present embodiment, red meat, that is, red meat and fruit flesh will be taken up and described as the irradiation target. Specifically, lean meat refers to lean meat such as beef, pork, whale meat, and horse meat, lean fish such as tuna, bonito, and horse meat, and fruits such as watermelon and melon. In this embodiment, beef is an object to be irradiated. Will be described as an example of. However, the irradiation target is not limited to beef, and may be other lean meat, white meat or green vegetables, and in the case of fish, the whole fish is the irradiation target, not the fillet. You can become. The lighting device 1 includes a light source device 2 which is a light source having a first spectrum, and in the present embodiment, the first spectrum is a spectrum corresponding to beef.

FIG. 3 shows an example of the spectral reflectance of beef with respect to wavelength. FIG. 3A is a graph showing the wavelength (nm) on the horizontal axis and the absolute value (%) of the spectral reflectance of beef on the vertical axis. In beef, the spectral reflectance is relatively high in the region of wavelength of about 600 nm or more, and the absolute value of the spectral reflectance exceeds 25%. The region where the spectral reflectance is relatively high is defined as the first wavelength region. It is desirable that the first wavelength region includes the wavelength having the highest reflectance in the visible light region. In the present embodiment, a region having a wavelength of 600 nm or more is the first wavelength region. The maximum wavelength of the first wavelength region in the present embodiment is, for example, 780 nm, which is the maximum wavelength of visible light, and a region having a wavelength of 600 nm or more and 780 nm or less may be used as the first wavelength region. The first wavelength region may be a wavelength region that exceeds the average value of the spectral reflectance in the visible light region. For example, in the case of the present embodiment, since the average value of the spectral reflectance of beef in the visible light region is about 19.3%, a region having a wavelength of 615 nm or more and 780 nm or less showing a reflectance higher than the spectral reflectance of 19.3%. May be the first wavelength region. By irradiating the beef with light centered on the light in the first wavelength region having high reflectance, the reflected light from the beef increases, and the effect of being vividly perceived by the human eye can be expected.

Basically, beef loses its freshness over time and changes its appearance from red to, for example, brown. In FIG. 3 (b), the horizontal axis is the wavelength (nm), and the vertical axis is the difference (%) of the spectral reflectance of beef for each unit time based on the initial state (for example, the day when beef is lined up in the store in a supermarket). This is an example of a graph showing. That is, it is an example of a graph showing the amount of change in the spectral reflectance of beef over time. If it is 0%, there is no change in the spectral reflectance from the initial state, and it is shown that the spectral reflectance fluctuates by moving away from 0% in the positive direction or the negative direction. For example, the line after 2 unit time is a line showing the difference between the initial state and the spectral reflectance after 2 unit time has elapsed.

In beef, there are a wavelength region in which the spectral reflectance hardly changes even after a unit time, and a wavelength region in which the spectral reflectance fluctuates every unit time. The wavelength region in which the spectral reflectance hardly changes is, for example, a region having a wavelength of 430 nm or less and a region having a wavelength of 680 nm or more. In the wavelength region where the spectral reflectance fluctuates, the freshness of the beef decreases and the spectral reflectance fluctuates over a unit time, and the degree of light reflection from the beef changes from the initial state. Humans perceive the change in light reflection with the naked eye and recognize the change in freshness. Therefore, if the beef is irradiated with light in a wavelength region in which the spectral reflectance fluctuates, it becomes easier to recognize the change in freshness.

Regarding the fluctuation of the spectral reflectance in beef, in the region of about 610 nm to about 650 nm, the difference in the spectral reflectance becomes negative as the unit time elapses, and the spectral reflectance tends to decrease. At a wavelength of 640 nm, the reflectance decreases by about 8.0% after 3 unit hours, and the absolute value of the spectral reflectance decrease becomes the largest.

In the first wavelength region (600 nm or more and 780 nm or less in this embodiment) in which the spectral reflectance is relatively high, the region in which the amount of decrease in the spectral reflectance with time is relatively large is defined as the second wavelength region. In the present embodiment, the region of about 610 nm to about 650 nm is the second wavelength region. It is desirable that this second wavelength region includes the wavelength at which the spectral reflectance is most reduced in the graph showing the fluctuation of the spectral reflectance over time. Further, the width of the second wavelength region may be the width of both ends where the valley falls in the valley portion where the fluctuation of the spectral reflectance starts to decrease, and the average value of the overall fluctuation of the spectral reflectance is used as a threshold value. The width of the region below the threshold value may be set as the width, or the half width with respect to the peak value at which the spectral reflectance is most lowered may be set as the width.

The illuminating device 1 includes a light source device 2 having a first spectrum having a first peak in a second wavelength region. In the present embodiment, the first spectrum of the light source device 2 is a spectrum corresponding to beef, and has a peak in a region of about 610 nm to about 650 nm, which is a second wavelength region.

Further, regarding the fluctuation of the spectral reflectance in beef, the difference in the spectral reflectance becomes positive after 3 unit hours in the region of about 450 nm to about 490 nm, and the spectral reflectance tends to increase. At a wavelength of 470 nm, the reflectance increases by about 1.5% after 3 unit hours, and the absolute value of the spectral reflectance increase becomes the largest. Further, although not shown in FIG. 3B, the reflectance increases by about 3.9% at a wavelength of 470 nm even after 4 unit hours, and the spectral reflectance increases over time after 3 unit hours. There is a tendency.

The region in which the amount of increase in the spectral reflectance with time is relatively large is defined as the third wavelength region. In the present embodiment, the region of about 450 nm to about 490 nm is the third wavelength region. It is desirable that this third wavelength region includes the wavelength at which the spectral reflectance is most increased in the graph showing the fluctuation of the spectral reflectance over time. Further, the width of the third wavelength region may be the width of both ends where the peak rises in the mountain portion where the fluctuation of the spectral reflectance starts to rise, or the average value of the overall fluctuation of the spectral reflectance is used as a threshold value. The width of the region exceeding the threshold value may be used, or the half width with respect to the peak value at which the spectral reflectance is most increased may be used as the width.

The illuminating device 1 includes a second light source 20 having a peak wavelength of 610 nm to 650 nm. That is, in the spectral reflectance of beef shown in FIG. 3A, a light source having a first wavelength region having a high spectral reflectance is provided. By irradiating the beef with light in a region where the spectral reflectance of the beef is high from the illuminating device 1, a large amount of reflected light from the beef can be obtained, and the effect of making the beef look more vivid can be expected. In order to obtain the effect of making beef look vivid, the light having a wavelength of 610 nm to 780 nm, which is a region having high spectral reflectance in FIG. 3A, may be used. However, the longer the wavelength of light, the lower the luminosity factor and the more difficult it is to perceive with the human eye. Therefore, in order to make beef look vivid, it is necessary to increase the amount of light, which may reduce efficiency. Therefore, by using light having a short wavelength (for example, 610 nm to 700 nm), it is possible to efficiently make the beef look vivid.

Further, since the second light source 20 of the lighting device 1 has a peak wavelength of 610 nm to 650 nm, the first wavelength region in which the spectral reflectance of the irradiated object is high, and the spectral reflectance of the irradiated object decreases with time. A light source having a peak in a second wavelength region, which is a region where the amount is relatively large, is provided. That is, in the present embodiment, the second light source 20 is in the first wavelength region where the spectral reflectance of the irradiated object is relatively high with respect to the wavelength, and the amount of decrease in the spectral reflectance of the irradiated object over time is relative. It is a light source having a first spectrum having a first peak in a large second wavelength region. In this second wavelength region, since the absolute value of the spectral reflectance is high and the amount of decrease in the spectral reflectance over time is relatively large, the fluctuation of the spectral reflectance over time is remarkable and the fluctuation range is large. It becomes an area. Therefore, by irradiating a light source having a peak in this second wavelength region, it becomes possible for the human eye to more faithfully perceive the change in spectral reflectance over time.

Further, the second light source 20 of the lighting device 1 has a half width of 10 nm to 40 nm. That is, the half width of the first peak in this embodiment is 10 nm to 40 nm. As described above, the first peak exists in the first wavelength region and the second wavelength region, but when the half width at the first peak is large, the light is emitted outside the first wavelength region or the second wavelength region. There is a risk of irradiating. In that case, the fluctuation of the spectral reflectance is not remarkable, and light is also irradiated to the wavelength region where the fluctuation range is small, so that the effect of being averaged and perceiving the change of the spectral reflectance over time is weak. Therefore, it may be difficult for the human eye to recognize the change in color of the irradiated object. Therefore, it is desirable that the full width at half maximum at the first peak is narrower than the width of the second wavelength region. In the present embodiment, the half-value width of the second light source 20 is 10 nm to 40 nm with respect to the width of the second wavelength region of about 40 nm, and the light source having a half-value width narrower than the width of the second wavelength region is used. The second light source 20 is used. Further, in the second light source 20 of the lighting device 1, two wavelengths constituting the half width of the first peak, that is, two wavelengths having half the intensity of the first peak are both present in the second wavelength region. Is preferable. Further, it is still preferable that the base (rising portion) constituting the first peak also exists in the second wavelength region.

Further, the lighting device 1 includes a first light source 10 having a peak wavelength of 450 nm to 490 nm. That is, in the beef showing the change in the spectral reflectance with time shown in FIG. 3 (b), the light source having the second peak in the third wavelength region in which the amount of increase in the spectral reflectance with time is relatively large. It has. Since the amount of increase in the spectral reflectance over time is relatively large, the light in this third wavelength region is a region in which the reflectance remarkably fluctuates in the increasing direction. Therefore, by irradiating the light source having the third wavelength region, it becomes possible for the human eye to more faithfully perceive the change in the spectral reflectance with time.

Further, the first light source 10 of the lighting device 1 has a half width of 10 nm to 40 nm. That is, the half-value width of the second peak in the present embodiment is 10 nm to 40 nm. As described above, the second peak exists in the third wavelength region, but if the full width at half maximum in the second peak is large, there is a risk of irradiating light outside the third wavelength region. In that case, the fluctuation of the spectral reflectance is not remarkable, and light is also irradiated to the wavelength region where the fluctuation range is small, so that the effect of being averaged and perceiving the change of the spectral reflectance over time is weak. Therefore, it may be difficult for the human eye to recognize the change in color of the irradiated object. Therefore, it is desirable that the full width at half maximum at the second peak is narrower than the width of the third wavelength region. In the present embodiment, the half-value width of the first light source 10 is 10 nm to 40 nm with respect to the width of the third wavelength region of about 40 nm, and the light source having a half-value width narrower than the width of the third wavelength region is used. The first light source 10 is used. Further, in the second light source 20 of the lighting device 1, two wavelengths constituting the half width of the second peak, that is, two wavelengths having half the intensity of the second peak are both present in the second wavelength region. Is preferable. Further, it is still preferable that the base (rising portion) constituting the second peak also exists in the second wavelength region.

As described above, the illumination device 1 includes a light source having a first spectrum having a peak in a wavelength region in which the spectral reflectance of beef fluctuates remarkably with time. Therefore, by irradiating the beef with light from the lighting device 1, the variation in the spectral reflectance of the beef can be emphasized and more faithfully captured by the human eye, so that the effect of showing the freshness of the beef more appropriately can be expected. .. That is, when the freshness is good, the freshness is good, and when the freshness is bad, the effect of showing the freshness is expected.

The same effect can be expected as long as it exhibits the same spectral reflectance characteristics as the beef shown in FIGS. 3 (a) and 3 (b). For example, the same effect can be expected with lean meat other than beef, lean fish, and even red and orange paints.

Next, a simulation result for verifying the effect of appropriately showing the freshness of beef, which is the irradiation target of the lighting device 1, is shown. In order to convert the change in the spectral distribution due to the freshness into the chromaticity as it is, the change in the chromaticity when the reference light and the conventional lighting device and the lighting device 1 each illuminate the beef was analyzed, using the reference light as equal energy white. The state in which the beef is illuminated with the reference light is the original chromaticity change of the beef, and the state in which the beef is illuminated by the conventional lighting device and the lighting device 1 corresponds to the chromaticity change perceived by the human eye. FIG. 4A shows the spectral distribution of the light emitted by the lighting device 1, and FIG. 4B shows the spectral distribution of the light emitted by the conventional lighting device. The light emitted by the illuminating device 1 used was one that satisfied the requirements of the light source device 2 described above. In addition, as the light emitted from the conventional lighting device, a light source having the effect of "making foods such as meat products, fresh fish, vegetables, and fruits displayed in showcases lively and bringing out the deliciousness" was used. .. A conventional lighting device has a blue light source having a peak wavelength of 450 nm and a half width of about 18 nm, and a red light source having a peak wavelength of 650 nm and a half width of about 88 nm. It also has a green or yellow light source with a peak wavelength of 525 nm and a half width of about 77 nm. The light emitted from the conventional lighting device is, for example, white light having a color temperature of 2923K and a color deviation of −0.029. In the simulation of the present embodiment, the reference light is equal energy white, and a spectrum showing a constant intensity in the wavelength region of visible light is used, but the reference light is not limited to equal energy white. In an actual usage pattern, the reference light can be sunlight, pseudo-sunlight, or halogen light.

The simulation results are shown in FIGS. 5 and 6. 5 and 6 are the results of simulating the fluctuations of the values of L ^* , a ^* , and b ^{* in} the L ^* a ^* b ^* coordinate system when the beef is irradiated with each light source every unit time. The unit time used in this simulation is one day. That is, the result of the unit time 3 is the values of L ^* , a ^* , and b ^* obtained when the beef in the state where 3 days have passed from the first day is irradiated with the reference light and the light sources of the conventional lighting device and the lighting device 1. This is the calculated result.

FIG. 5 is a line graph in which the vertical axis is the L ^* value, the horizontal axis is the unit time, and the fluctuation of the L ^* value for each unit time is simulated. The fluctuation tendency of the L ^* value for each unit time is the same for the reference light, the conventional lighting device, and the lighting device 1, and the L ^* value decreases by about 5% after 1 unit time (1 day), and thereafter. The L ^* value fluctuates at a fluctuation rate of 1% or less / unit time. Regarding the L ^* value, the value radiated by the conventional light source and the illuminating device 1 is higher than that irradiating by the reference light source, but the L ^* value obtained by irradiating with the illuminating device 1 is closer to the reference light source than the conventional light source. Has been done. The higher the L ^* value, the higher the brightness and the higher the effect of making it look vivid. In other words, it can be said that the L ^* value and the appearance of freshness are proportional. That is, from the viewpoint of the L ^* value, both the lighting device 1 and the conventional light source have the effect of making the lighting device look fresher than the case of irradiating with the reference light from the initial stage to the lapse of 4 unit times, and the effect is the conventional light source. It can be said that the appearance is closer to the original freshness when irradiated with the lighting device 1.

FIGS. 6 (a) and 6 (b) show the results of simulating the fluctuation of chromaticity on a ^* b ^* two-dimensional coordinates. On the a ^* b ^* two-dimensional coordinates shown in FIGS. 6 (a) and 6 (b), the larger the value in the red direction a ^* , the higher the saturation in the red direction, and the larger the value in the yellow direction b ^* , the higher the saturation in the yellow direction. It shows that the saturation of the color looks high. In general, beef with good freshness tends to have a high value of a ^* because of its high saturation in the red direction, and beef with low freshness tends to have a low value of a ^* . In addition, the value of b ^* also tends to decrease with freshness.

FIG. 6A is a result of comparing the case where the beef is irradiated with the conventional lighting device and the case where the beef is irradiated with the reference light. The chromaticity when beef is irradiated with each light source from the initial state to the lapse of 4 unit hours (4 days in this simulation) is shown. From the initial state until after 4 the unit time, the chromaticity when irradiated with beef reference light + a ^* about -8.7 points, fluctuating about -6.0 points + b ^*. In other words, it indicates that the freshness of the beef decreased and the redness and yellowness weakened by the time when 4 unit hours had passed from the initial state.

In the initial state, the chromaticity when beef is irradiated with the conventional light source device is different from the reference light by about +5.0 points at + a ^* and about +7.8 points at + b ^* . .. That is, as shown in FIG. 6 (a), in the initial state, the chromaticity plot points of the conventional light source device are larger than the chromaticity plot points of the reference light in both a ^* and b ^* on the a ^* b ^* two-dimensional coordinates. It will be located in the upper right direction, which is the value. In addition, this result indicates that when beef is irradiated with a conventional light source device in the initial state, red and yellow can be felt more vividly than the original color irradiated with the reference light, and the freshness can be felt.

After 4 units of time, the chromaticity when beef is irradiated with the conventional light source device is about +5.8 points for + a ^* and about +6.7 points for + b ^* compared to the reference light. It has become. That is, as shown in FIG. 6A, the chromaticity plot points of the conventional light source device are a ^* , b from the chromaticity plot points of the reference light even after 4 unit times have elapsed on the a ^* b ^* two-dimensional coordinates. ^* Both will be located in the upper right direction, which is a large value. In addition, this result shows that even after 4 unit hours have passed, when the beef is irradiated with the conventional light source device, the freshness can be felt more than the original appearance irradiated with the reference light.

Therefore, at any time, when beef is irradiated with a conventional lighting device, the beef looks brighter in red and yellow than when it is irradiated with reference light that is close to the original appearance of beef. It will be. In this case, in the initial state, there is no particular problem because the fresh beef looks more colorful, but there is a possibility that a problem may occur when the unit time elapses and the freshness decreases. For example, when beef that has passed 4 unit hours (4 days in this simulation) from the initial state is irradiated with a conventional lighting device, the appearance of beef that has passed 1 unit time (1 day in this simulation) from the initial state is The appearance is almost the same as when illuminated with reference light. In other words, beef that should have deteriorated in freshness after 4 days will appear to be as fresh as 1 day. Therefore, there is a risk that the customer may purchase beef whose freshness has deteriorated without feeling uncomfortable by mistaking the timing of lowering the beef from the store. Therefore, it is desirable that the visual appearance and the actual freshness are in balance after the unit time has passed.

FIG. 6B is a result of comparing the lighting device 1 with the reference light. It shows the chromaticity when beef is irradiated with each light source from the initial state to the lapse of 4 unit hours. It can be confirmed that the plot points of the lighting device 1 and the reference light do not deviate significantly from each other as compared with the case of irradiating with the conventional lighting device shown in FIG. 6A. That is, by irradiating the beef with the lighting device 1, it is possible to show the original color of the beef irradiated with the reference light.

In the initial state, the chromaticity when irradiated beef lighting device 1, as compared to the reference light + a ^* about +0.4 points, a difference of about +1.5 points + b ^*. That is, as shown in FIG. 6B, in the a ^* b ^* two-dimensional coordinates, in the initial state, the chromaticity plot points of the illuminating device 1 are larger than the chromaticity plot points in the reference light for both a ^* and b ^*. It will be located in the upper right direction, which is the value. In addition, this result shows that, in the initial state, when the beef is irradiated with the lighting device 1, the beef can be felt fresher than the original appearance irradiated with the reference light, although it is not as good as the conventional light source device.

After 4 units of time, the chromaticity when beef is irradiated with the lighting device 1 is about +2.7 points for + a ^* and about 2.9 points for + b ^* compared to the reference light. It has become. That is, as shown in FIG. 6 (b), on the a ^* b ^* two-dimensional coordinates, after 4 unit times have elapsed, the chromaticity plot point in the illuminating device 1 is a ^* from the chromaticity plot point in the reference light. A large value, b ^*, is located in the lower right direction, which is a small value. In addition, this result shows that after 4 units of time, when beef is irradiated with the lighting device 1, the red color is brighter and the yellow color is less bright and dull than the original appearance of the light irradiation. Shown.

Comparing the case of irradiating beef with the conventional light source device and the case of irradiating beef with the lighting device 1 from the initial state to the lapse of 4 unit hours, as described above, it is more standard to irradiate the beef with the lighting device 1. It shows the original chromaticity of beef, which is close to light. Therefore, irradiating the beef with the lighting device 1 can more faithfully represent the change in chromaticity due to the decrease in the freshness of the beef. Therefore, by irradiating the beef with the lighting device 1, it can be expected that the freshness of the beef is good when the freshness of the beef is good, and the freshness of the beef is low when the freshness of the beef is poor.

In the present embodiment, when irradiated with beef illumination apparatus 1, after the unit time has elapsed, the chromaticity plot point of the lighting device 1 than chromaticity plot points of the reference light is a ^* is a large value, b ^* is smaller However, as a more preferable example, the chromaticity plot points of the conventional light source device are smaller than the chromaticity plot points in the reference light for both a ^* and b ^*. It is desirable to be located in the lower left direction. By locating the plot point after the lapse of a unit time in the lower left direction from the plot point in the reference light, it is possible to make the beef to be irradiated look worse than the color when it is irradiated with the reference light. The effect of making it easier to recognize changes in freshness can be expected. That is, as a preferred embodiment, by irradiating the irradiation target with the illumination device 1, in the initial state, the irradiation target is irradiated with the reference light source on the a ^* b ^* two-dimensional coordinates to the upper right of the plot point. After the unit time has elapsed, it is preferably plotted at the lower left of the plot point when the irradiation target is irradiated with the reference light source on the a ^* b ^* two-dimensional coordinates.

A more preferable condition is to irradiate the irradiation target with the illumination device 1, and in the initial state, plot the irradiation target on the a ^* b ^* two-dimensional coordinates to the upper right of the plot point when the irradiation target is irradiated with the reference light source. In addition to the above conditions, it is still preferable that the L ^* value shows a value larger than that when irradiated with the reference light source. In other words, in the CIE L ^* a ^* b ^* three-dimensional coordinate space, the L ^* value, a ^* value, and b ^* value are all larger than the plot points when the irradiation target is irradiated with the reference light source. It is still preferable that the plot points when the irradiation target is irradiated by the illumination device 1 are plotted. Furthermore, after the lapse of a unit time, by irradiating the irradiation target with the illumination device 1, the condition is plotted at the lower left of the plot point when the irradiation target is irradiated with the reference light source on the a ^* b ^* two-dimensional coordinates. In addition, it is still preferable that the L ^* value shows a smaller value than when irradiated with a reference light source. In other words, in the three-dimensional coordinate space of L ^* a ^* b ^* , the L ^* value, a ^* value, and b ^* value are all smaller than the plot points when the irradiation target is irradiated with the reference light source. It is still preferable that the plot points when the irradiation target is irradiated by the illumination device 1 are plotted. In this way, by adding the magnitude of the L ^* value to the judgment condition, it can be expected to enhance the effect of making it easier to recognize the change in freshness.

Next, the simulation results in the L ^* a ^* b ^* three-dimensional coordinate space will be introduced. The L ^* a ^* b ^* 3-dimensional coordinate space, performs Delta] E _rn represented by the following formula (1), Delta] E _tn of the following formula (2), the evaluation even FI _n represented by the following formula (3).
Note that n is a parameter indicating a unit time, and any positive number may be applied. Since n is given for unit time management, it is not always necessary to indicate it. That is to say, as for the evaluation parameters without notation n, ΔE _r, ΔE _t, it may be evaluated as FI.

“L ^* ”, “a ^* ”, and “b ^* ” used in the formulas (1) to (3) are the values of L ^* , a ^* , and b ^* as they are. "R" is an alphabet indicating the reference light. The reference light here may be isoenergy white, sunlight, or halogen light. "T" is an alphabet indicating test light. The test light here is light emitted from the lighting device 1 or the conventional lighting device. "0" is a number indicating the initial state. Although "n" is an alphabet representing a unit time, any positive number may be applied in the actual evaluation.

Specifically, the parameters of equations (1) to (3) will be explained. In the following, "L ^* 〇 ☆" (○: r or t, ☆: 0 or n or any positive number) will be taken up and explained, but the same applies to "a ^* 〇 ☆" and "b ^* 〇 ☆". Therefore, the part of "L ^* value" is simply replaced with "a ^* value" or "b ^* value". “L ^* r0” indicates “L ^* value when the initial state is irradiated with reference light”. “L ^* rn” indicates “L ^* value when irradiated with reference light after n unit times”. By applying "1" as an arbitrary positive number to this "n" and setting it as "L ^* r1", "L ^* value when irradiated with reference light after 1 unit time" is indicated. “L ^* t0” indicates “L ^* value when the initial state is irradiated with test light”. “L ^* tun” indicates “L ^* value when irradiated with test light after n units of time”. By applying "2" as an arbitrary positive number to this "n" and setting it as "L ^* t2", "L ^* value when irradiated with reference light after 2 unit hours" is indicated.

That is, ΔE _rn represents the amount of movement of the plot points n units of time after the plot points in the initial state in the L ^* a ^* b ^* three-dimensional coordinate space when the irradiation target is irradiated with the reference light. Similarly, ΔE _tn represents the amount of movement of the plot points n units of time after the plot points in the initial state in the L ^* a ^* b ^* three-dimensional coordinate space when the irradiation target is irradiated with the test light. .. And FI _n represents the difference between the amount of movement in the test light and the amount of movement in the reference light. If FI _n is a positive value, it means that the amount of movement in the L ^* a ^* b ^* three-dimensional coordinate space is larger when the irradiation target is irradiated with the test light than with the reference light. That is, it is shown that it is easier for the human eye to recognize the change in the color of the irradiated object (that is, the change in freshness) when the irradiated object is irradiated with the test light rather than the reference light. Further, the larger the value of FI _n, the more remarkable the effect.

L ^* a ^* b ^{* When} performing the simulation in the three-dimensional coordinate space, the reference light E, which is closer to the actual usage environment, was used as the reference light. The reference light E is a white light source having a color temperature of 5456K and Ra95. As the test light, the lighting device 1 and the conventional lighting device shown in FIGS. 4A and 4B were used. Beef was used as the light irradiation target, and each parameter was compared between the initial state and the unit time after one day. Therefore, in the following, "1" is applied to the above-mentioned parameter "n" according to the situation. In the following, the coordinates in the L ^* a ^* b ^* three-dimensional coordinate space are defined, and specifically, the coordinates when irradiated with the reference light E are E0 or E1, and the coordinates when illuminated by the lighting device 1 are defined. H0 or H1, the coordinates when illuminated by a conventional lighting device are defined as G0 or G1. The numbers attached to the coordinates indicate the unit time, where 0 is the initial state and 1 is the coordinates after 1 unit time. For example, E0 is the coordinates in the L ^* a ^* b ^* three-dimensional coordinate space when the beef in the initial state is irradiated with the reference light E, and H1 is the coordinates when the beef is irradiated one unit time later with the lighting device 1. L ^* a ^* b ^* Coordinates in a three-dimensional coordinate space.

FIG. 9 shows the values of L ^* , a ^* , and b ^* under each condition. In the initial state, the values of L ^* , a ^* , and b ^* are higher than those of the reference light in both the case of irradiation with the lighting device 1 and the case of irradiation with the conventional lighting device. That is, the coordinates H0 in the lighting device 1 and the coordinates G0 in the conventional lighting device are located above the coordinates E0 in the reference light E. Further, in the L ^* a ^* b ^* three-dimensional coordinate space, the coordinate G0 in the conventional lighting device exists above the coordinate H0 in the lighting device 1. Therefore, in the initial state, the beef looks more vivid when the beef is irradiated with the lighting device 1 or the conventional lighting device than when the beef is irradiated with the reference light.

One day later, when illuminated by the lighting device 1, L ^* shows a value higher than the reference light, but the a ^* value is lower than the reference light and the b ^* value is almost the same as the reference light. .. Further, when the conventional lighting device is used for irradiation, all the values of L ^* , a ^* , and b ^* are higher than those when the reference light is used for irradiation. That is, in the L ^* a ^* b ^* three-dimensional coordinate space, the coordinate H1 in the lighting device 1 is downward or leftward (strictly speaking, the b ^* value is almost the same) than the coordinate E1 in the reference light E one day later. Therefore, the two-dimensional coordinates of L ^* a ^* are downward, the two-dimensional coordinates of L ^* b ^* are left, and the two-dimensional coordinates of a ^* b ^* are left), and the coordinate G1 in the conventional lighting device is upward. Existing. Therefore, when comparing the case where the beef is irradiated one day later with the reference light and the case where the beef is irradiated one day later with the lighting device 1, the freshness of the beef seems to be almost the same in both cases. In detail, since the coordinate H1 in the lighting device 1 shows a smaller value, it seems that the freshness is worse when the beef is irradiated by the lighting device 1. In addition, comparing the case of irradiating the beef one day later with the reference light and the case of irradiating the beef one day later with the conventional lighting device, the beef is fresher and more vivid when the conventional lighting device is used to irradiate the beef. Looks like.

When ΔE _r1 represented by the equation (1) and ΔE _t1 represented by the equation (2) are calculated using the parameters shown in FIG. 9, ΔE _r1 = 3.4 and ΔE _t1 (lighting device 1) = 4. .4, ΔE _t1 (conventional lighting device) = 3.6. That is, the amount of movement of the coordinates one day after the initial state in the L ^* a ^* b ^* three-dimensional coordinate space is the largest when illuminated by the illuminating device 1, and the change in the appearance color one day after the initial state. Indicates that is the largest.

Next, when FI ₁ represented by the equation (3) is calculated, FI ₁ (illumination device 1) = 1.0 and FI ₁ (illumination device 1) = 0.3, and the amount of movement compared with the reference light is It is calculated. In order to appropriately show the color of the irradiation target, it is desirable to use a light source in which the movement amount of the coordinates is larger than the movement amount of the coordinates when the irradiation target is irradiated with the reference light. Therefore, it is desirable that the FI value is a positive value, and it is even more desirable that the absolute value of the FI value is large.

In addition, a lighting device having the spectral distribution shown in FIG. 4 was actually manufactured, and the beef with high freshness in the initial state and the beef with low freshness after a unit time were irradiated with the light of these lighting devices, and the subject A test was conducted to confirm. As a result, when the light was irradiated by the illumination device having the spectral distribution shown in FIG. 4 (a), the difference in freshness could be clearly confirmed visually, and when the light was irradiated by the illumination device having the spectral distribution shown in FIG. 4 (b), the freshness was noticeable. There were many opinions that it was difficult to visually catch the difference even if the change was made, and the result was roughly in agreement with the simulation result.

The 1 unit time in this embodiment is, for example, one day. The freshness of the object (beef in this embodiment) may decrease quickly or slowly depending on the surrounding environment such as temperature and humidity when it is stored and stored. Therefore, depending on the surrounding environment at the time of storage and storage, the rate variation of the spectral reflectance shown in FIG. 3B may be exhibited even in a unit time shorter than one day or a unit time longer than one day.

Next, a first modification is shown in FIG. As a first modification, not a form in which a control signal is input to the lighting device 1 from the outside but a form in which information on an object is input to the lighting device 1 from the outside may be used. In this case, as shown in FIG. 7, the lighting device 1 is provided with a processing unit 70 for inputting information on the object. The receiving unit 60 receives the information of the object transmitted from the outside, and the receiving unit 60 inputs the information of the object to the processing unit 70. The processing unit 70 determines the control method from the input information of the object. After that, control information is output from the processing unit 70, and the lighting control unit 3 that receives the control information controls the light source unit 2. The processing unit 70 includes, for example, a processor and a CPU.

The object information input to the processing unit 70 is, for example, image data such as actual image data or thermal image data acquired by a camera or sensor, reflectance information, color information, temperature information, displacement information, and the like. It may be numerical data of. The camera and the sensor may be installed in the building separately from the lighting device 1, or may be installed in the portable communication device.

The processing in the processing unit 70 includes a step of extracting the current data of the object, a step of calculating the difference by comparing with the data of the previously extracted object, and a step of determining whether the difference exceeds the threshold value. When the threshold value is exceeded, a step of determining the control method according to the degree of exceeding the threshold value and a step of outputting control information are provided. For example, when the input information of the object is actual image data, the spectral reflectance is extracted from the image data as the current data of the object, the difference from the previously acquired spectral reflectance is calculated, and the difference is obtained for each wavelength. It may be a step of determining that the value exceeds the threshold value, determining the control of increasing the emission intensity at the wavelength exceeding the threshold value, and outputting the control information. If the input object information is reflectance data, the input reflectance data is used as the current data, the difference from the previously input reflectance data is calculated, and the difference exceeds the threshold for each wavelength. However, it may be determined that the control for increasing the emission intensity of the wavelength exceeding the threshold is determined, and the control information may be output.

The processing unit 70 may include a storage unit in which data in which the object and the control method are linked in advance are stored. In that case, the processing in the processing unit 70 includes a step of recognizing what and what state the object is in, a step of collating the recognized object state with the data of the storage unit and selecting a control method, and control information. It may be a step to output. At this time, as a control method, the output change for each time may be stored, or only the output change may be simply stored. Further, the processing unit 70 may be connected to the cloud server to search and collate the data on the cloud server.

The control information output from the processing unit 70 may be, for example, a control signal itself or communication data required for control.

Further, the receiving unit 60 and the processing unit 70 may be integrally formed, or the lighting control unit 3 may be provided with the functions of the receiving unit 60 and the processing unit 70. Further, the processing in the processing unit 70 may be performed on the cloud server. In this case, the configuration of the lighting device 1 may be the configuration shown in FIG. 1, and the processing unit 70 may not be arranged. The information of the object is directly transmitted to the cloud server, processed by the cloud server, and the control information is transmitted to the lighting device 1. The control information is received by the receiving unit 60, and then the lighting control unit 3 that has received the control information controls the light source unit 2.

Next, a second modification is shown in FIG. As a second modification, the lighting device 1 may acquire information on an object instead of inputting a signal or information from the outside to the lighting device 1. In this case, as shown in FIG. 8, the lighting device 1 is provided with an acquisition unit 80 for acquiring information on the object. The information of the object acquired by the acquisition unit 80 is input to the processing unit 70. The processing unit 70 determines the control method from the input information of the object. After that, control information is output from the processing unit 70, and the lighting control unit 3 that receives the control information controls the light source unit 2.

The acquisition unit 80 is provided with, for example, a camera or a sensor, and acquires image data such as actual image data and thermal image data, and numerical data such as reflectance information, color information, temperature information, and displacement information.

Further, the acquisition unit 80 and the processing unit 70 may be integrally formed, or the lighting control unit 3 may be provided with the functions of the acquisition unit 80 and the processing unit 70. Further, both the receiving unit 60 and the acquiring unit 80 may be provided so as to correspond to both the first modified example and the second modified example 2. Further, also in the second modification, the processing in the processing unit 70 may be performed on the cloud server. By uploading the information of the object on the cloud server once, the information of the object can be accumulated and monitored smoothly, or the same control information is passed to multiple lighting devices to irradiate the same light from multiple units. It becomes possible to do. It is also possible to learn the process by collecting information on the object on the cloud server and provide more appropriate lighting control.

Further, the lighting device 1 may be equipped with a plurality of types of light source devices 2. In this case, each light source device 2 has a first spectrum corresponding to a different object, and the lighting device 1 has a form capable of irradiating a plurality of objects. In this case, a processing unit 70 for inputting information on the irradiation target is provided on the lighting device 1 or the network, and after the processing unit 70 determines the irradiation target, the first spectrum corresponding to the irradiation target is irradiated. You may perform control to do so.

Next, a case where the first modification is used in a yakiniku restaurant will be described. A photograph of beef placed on a net is taken with a camera of a smartphone, for example, and transmitted to the lighting device 1. The lighting device 1 performs lighting control according to the state of baking based on the received photograph. For example, if the surface of the meat is lightly baked, the redness of the baked meat is emphasized, and if the meat is slowly baked, the contrast is made clear and the meat is recognized before it is burnt.

Next, a case where the second modification is used in a supermarket will be described. An example of acquiring the reflectance is shown as the information of the object. First, when the beef display is completed, the lighting device 1 acquires the reflectance of the object as initial data. At this time, the lighting control that makes the beef look vivid may be performed by referring to the initial data. Further, as the initial data, the data in the storage unit or the cloud server may be used. Then, the reflectance of the object is acquired by the lighting device 1 for each unit time (for example, 1 hour), and the difference from the reflectance acquired in the previous unit time is calculated. After that, it is determined that the difference in reflectance for each wavelength exceeds the threshold value, and if there is no wavelength exceeding the threshold value, the illumination control is not changed. When there is a wavelength exceeding the threshold value, illumination control is performed to increase the emission intensity at the wavelength exceeding the threshold value. This lighting control makes it easier to visually recognize the beef that has deteriorated over time, so it is possible to prevent customers from purchasing the beef that has deteriorated in freshness, and the beef that has deteriorated in freshness is also displayed at the store. Can be removed from.

At this time, the illuminating device 1 may include a fourth light source having a peak wavelength of 680 nm or more, turn on the fourth light source in the initial state, and control the output of the fourth light source to decrease over time. .. As shown in FIG. 3A, the fourth light source is a light source that irradiates light in a region where the reflectance of beef is high. Therefore, in the initial state, the beef can be made to look vivid by turning on the fourth light source. After that, when the freshness of the beef has deteriorated after a lapse of time from the initial state, it is less necessary to make the beef look vivid, so the output of the fourth light source is lowered or the output is set to 0. As a result, it is possible to appropriately irradiate light that enhances purchasing motivation in the initial state and light that shows a state of reduced freshness in a state of reduced freshness.

In the present embodiment, a food product is selected as an object and beef is particularly selected and described, but the present embodiment is not limited to this embodiment. For example, the same effect can be expected with pork, chicken, etc. instead of beef, and a structure coated with paint instead of food may be irradiated as an object. In the case of a structure coated with paint, not only the paint deteriorates and the appearance is impaired every unit time from the initial state, but also the waterproof performance may be deteriorated, for example. By irradiating the structure with the lighting device shown in the present embodiment, it is possible to appropriately recognize that the paint has deteriorated.

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 novel 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 modifications thereof are included in the scope and gist of the invention, and are also included in the scope of the invention described in the claims and the equivalent scope thereof.

1 Lighting device 2 Light source device 3 Lighting control unit 10 1st light source 20 2nd light source 30 3rd light source 40 Power supply device 50 Control unit

Claims (5)

An illuminating device that has a first wavelength region having a relatively high spectral reflectance with respect to a wavelength and irradiates an object whose spectral reflectance with respect to a wavelength fluctuates with time.
A light source having a first spectrum having a first peak in the second wavelength region, which is the first wavelength region and in which the amount of decrease in spectral reflectance over time in the object is relatively large, is provided.
A lighting device characterized in that the full width at half maximum at the first peak is narrower than the width of the second wavelength region.
The light source includes a second peak in a third wavelength region in which the amount of increase in spectral reflectance over time in the object is relatively large.
The lighting device according to claim 1, wherein the full width at half maximum at the second peak is narrower than the width of the third wavelength region.
The illuminating apparatus according to claim 1, further comprising a plurality of light sources having first spectra corresponding to a plurality of objects;
Further provided with a processing unit for inputting information on the object;
An illumination system characterized by controlling a light source having a first spectrum corresponding to the object based on information of the object input to the processing unit.
An illumination method for irradiating an object having a first wavelength region having a relatively high spectral reflectance with respect to a wavelength and having a spectral reflectance with respect to a wavelength fluctuating with time.
With the step of inputting the information of the object into the processing unit;
Based on the information of the object input to the processing unit, the first peak is in the first wavelength region and the second wavelength region in which the amount of decrease in the spectral reflectance with time of the object is relatively large. The step of irradiating the object with a light source having a first spectrum having the above-mentioned, and having a half-value width at the first peak narrower than the width of the second wavelength region;
Lighting methods including.
The object in the initial state is irradiated with light satisfying L ^* ≧ 41.0, a ^* ≧ 23.5, b ^* ≧ 16.5 in the CIE L ^* a ^* b ^* color space, and is spectroscopic. Irradiating the object after the reflectance fluctuation with light satisfying L ^* ≤39.0, a ^* ≤20.7, and b ^* ≤16.5 in the CIE L ^* a ^* b ^* color space. The lighting device according to claim 1.