JP2023121043A - Light irradiation device - Google Patents

Abstract

To provide a technology for suppressing impact on humans or animals, enhancing reliability of repelling insects and repelling insects with irradiation with light.SOLUTION: A light irradiation device (1) prevents insects from intruding from a first space (100) to a second space (200) by forming an insect temperature rising region (300) for raising temperature of insects by irradiating between those spaces with light having a wavelength between 1.4 μm and 3 mm.SELECTED DRAWING: Figure 1

Description

The present invention relates to a light irradiation device.

In public health and agriculture and livestock industries, sanitation problems and infectious disease vectors by pests result in decreased quality of life (QOL) and great social loss. In particular, blood-sucking and flying insects such as mosquitoes and flies can cause diseases such as dengue or West Nile fever in humans. Biting flies can also be a factor causing mastitis. It is said that 17% of infectious diseases affecting humans are transmitted by insects, and the number of deaths due to such infectious diseases is said to be as high as 700,000 per year.

In addition, due to recent global warming, the habitat of insects is also changing. Therefore, it is necessary to prepare for the threat of tropical diseases even in areas that have not been considered a problem until now. Against this background, there is a demand for a technique for repelling insects to specific areas.

Techniques for repelling insects include a technique of irradiating an LED with strong light having a cool white spectrum having two peaks, a first peak at about 450-470 nm and a second peak at about 500-700 nm. (See Patent Document 1, for example).

In addition, in the technology for repelling insects, near-infrared laser light is scanned indoors at a speed faster than the flight speed of flying insects, and the insects that repel the near-infrared laser light are moved indoors. Techniques for guiding to a specific target position are known (see Patent Document 2, for example).

Furthermore, as a technique for repelling insects, a technique is known in which light with a wavelength of 780 to 1350 nm is emitted while blinking at a specific irradiation intensity and in a specific cycle to make the insects repel the irradiation area of the light. (See Patent Document 3, for example).

Japanese Patent Publication No. 2020-527961 JP 2017-023014 A JP 2019-058125 A

However, the conventional techniques as described above have the following problems when applied to areas where humans or animals exist.

The above-described prior art utilizes the property (negative phototaxis) of insects irradiated with specific light to avoid the light. Therefore, when applied to an area where humans or animals exist, since the above-mentioned specific light is irradiated to humans or animals, especially in the case of irradiating visible light as in the technique described in Patent Document 1, irradiation Light can stress humans or animals. In addition, the mechanism of the above properties has not yet been elucidated, and the problem is that the effects are not uniform due to individual differences in insects.

In addition, blood-sucking and flying insects generally detect various components such as carbon dioxide emitted by humans or animals, approach humans or animals, and suck blood. Therefore, in the above-described prior art, when the strong blood-sucking trigger for the insect exceeds the negative phototaxis, repelling of the insect may be insufficient.

Thus, in the prior art, there is room for examination from the viewpoint of suppressing the effect on humans or animals to be repelled by insects and increasing the certainty of repelling insects in the technique of repelling insects by light irradiation. is left.

An object of one aspect of the present invention is to realize a technique for repelling insects by light irradiation, which can suppress the influence on humans or animals and increase the certainty of repelling insects.

In order to solve the above problems, a light irradiation device according to an aspect of the present invention provides a space between the first space and the second space in order to prevent insects from entering the second space from the first space. Between the two spaces, an insect temperature raising region is formed in which the temperature of insects is raised by irradiation of light having a wavelength of 1.4 μm or more and 3 mm or less.

ADVANTAGE OF THE INVENTION According to one aspect of the present invention, it is possible to realize a technology for repelling insects by light irradiation, which suppresses the influence on humans or animals and increases the certainty of repelling insects.

It is a figure which shows typically an example of a structure of the light irradiation apparatus which concerns on embodiment of this invention. It is a figure which shows typically the other example of a structure of the light irradiation apparatus which concerns on embodiment of this invention. 1 is a top view schematically showing the configuration of an experimental device used in Experimental Example 1. FIG. FIG. 4 is a diagram schematically showing a cross section of the experimental apparatus taken along line AA in FIG. 3; FIG. 3 is a diagram showing an example of the results of observation of Aedes albopictus in a cell with a thermal camera in Experimental Example 1. FIG. 2 is a diagram showing an example of temperature change of a specific Aedes albopictus in Experimental Example 1. FIG. FIG. 2 is a diagram showing an example of the results of observation of Aedes albopictus perched on the wall surface of a cell with a thermal camera in Experimental Example 1. FIG. 2 is a diagram showing an example of temperature change of Aedes albopictus perched on the wall surface of the cell in Experimental Example 1. FIG. FIG. 10 is a diagram showing an example of temperature change of a specific Aedes albopictus in Experimental Example 2. FIG.

A light irradiation device according to an embodiment of the present invention is a device for repelling insects from entering a specific area by remotely warming the insects with light irradiation.

Insects generally have heat-sensitive tissues. For example, mosquitoes are known to have a heat sensitive protein called TRPA1. Mosquitoes not only search for blood-sucking targets using this protein, but also move in search of a comfortable temperature. In the embodiment of the present invention, by utilizing the heat-sensing ability of such insects, the insects absorb light to raise their body temperature (photothermal (PT) effect), thereby causing the insects to escape and avoid behavior. provoke. An embodiment of the present invention will be described in more detail below. In this specification, "-" represents a range of more than or equal to the numerical values before and after it.

[Embodiment 1]
FIG. 1 is a diagram schematically showing the configuration of a light irradiation device according to an embodiment of the present invention. As shown in FIG. 1 , the light irradiation device 1 has a light source 11 and an optical system 12 . The light irradiation device 1 forms an insect temperature raising region 300 between the first space 100 and the second space 200 to raise the temperature of insects by irradiating light. The insect heating area 300 will be described later.

[light source]
The light source 11 emits light having a wavelength of 1.4 μm to 3 mm (hereinafter also generally referred to as “infrared light”). The number of light sources 11 can be appropriately determined within a range in which the insect heating area 300 can be formed, and may be singular or plural.

In the light irradiation device 1, the wavelength of the infrared light that forms the insect temperature rising region 300 should be the above wavelength. Therefore, the light source 11 may be a device that emits infrared light having the wavelength described above, and the optical system 12 includes a wavelength conversion element that converts the wavelength of the incident light into the wavelength of the infrared light and emits the infrared light. Then, it may be a device that emits light having a wavelength other than the above.

From the standpoint of suppressing the effects on humans or animals and from the standpoint of enhancing the effect of repelling insects, the longer the wavelength of the infrared light, the better.

In addition, from the viewpoint of reducing the effects on humans or animals, the wavelength of the infrared light is preferably a wavelength other than the water absorption region (about 3 μm and about 6 μm) within the above wavelength range. On the other hand, by adopting a configuration in which insects are intensively irradiated while avoiding irradiation of humans or animals, the absorption region of water can be actively used, and light in the wavelength range of 1.4 μm to 3 mm can be used. By doing so, the temperature can be efficiently raised.

The wavelength of the light forming the insect temperature rising region 300 can be appropriately set within the above range for various preferable reasons. For example, when the wavelength of the light forming the insect heating region 300 is 1.4 to 11 μm, a laser can be used as the light source for emitting light of this wavelength. Therefore, it is preferable from the viewpoint of the degree of freedom in selecting the light source.

Moreover, when the wavelength of the light forming the insect temperature rising region 300 is 1.4 to 3 μm, the temperature can be raised particularly through chitin, protein and water. Therefore, compared to visible light, it is safer to the human eye.It is also safer to humans and animals because it can selectively raise the temperature of the components peculiar to insects. It is preferable from the viewpoint of being able to use

Moreover, when the wavelength of the light forming the insect temperature-raising region 300 is 3 to 6 μm, the temperature can be raised particularly through chitin, wax components, protein and water. Therefore, it is safer to the human eye than visible light, and it is also safer to humans and animals because it can selectively raise the temperature of insect-specific components. This is preferable from the viewpoint of being able to use the existing quantum cascade laser.

Moreover, when the wavelength of the light forming the insect temperature-raising region 300 is 6 μm to 11 μm, the temperature can be raised particularly through chitin, wax components, protein and water. Therefore, compared to visible light, it is safer to the human eye.It is also safer to humans and animals because it can selectively raise the temperature of insect-specific components. It is preferable from the viewpoint that it can be used.

Moreover, when the wavelength of the light forming the insect temperature-raising region 300 is 11 μm to 3 mm, the temperature can be raised particularly through chitin, protein and water. Therefore, it is preferable from the viewpoint that it is safer to human eyes than visible light and that it is safer to humans and animals because it can selectively raise the temperature of components peculiar to insects.

Also, the absorbance of infrared light varies depending on the constituents of the insect part. For example, insects are composed of chitin, wax components, proteins, and the like that form the skeleton. These components have characteristic absorption peaks for light. Therefore, from the viewpoint of enhancing the repelling effect on insects, it is preferable that the wavelength of the infrared light be a wavelength corresponding to the absorption peak specific to the constituents of the insect parts.

Also, the amount of insect constituents varies depending on the type of insect. Therefore, when setting the type of insect to be repelled, the wavelength of the infrared light should be a wavelength corresponding to the light absorption peak specific to the type of insect, from the viewpoint of enhancing the insect repelling effect. preferred from

Moreover, the light source 11 may emit infrared light of sufficient intensity to repel insects in the insect heating region 300 . The intensity of the infrared light can be appropriately determined, for example, according to the dimensions of the insect heating area 300 .

Also, the intensity of the infrared light can be determined according to the type of insect. The temperature at which insects heated by infrared light start repelling behavior tends to differ depending on the type of insect. For example, even among mosquitoes, the temperature at which repellent behavior is initiated in tropical mosquitoes is usually higher than that of temperate mosquitoes. When setting an insect to be repelled, it is preferable to select the light source 11 capable of forming the insect temperature raising region 300 with infrared light having an intensity corresponding to the target insect.

From the viewpoint of increasing the certainty of repelling behavior of insects, the maximum value of the energy density of infrared light in the insect heating region 300 is preferably 0.01 nJ/mm ² to 10 J/mm ² . Alternatively, for the same reason, the maximum value of the average power density of infrared light in the insect heating area 300 is preferably 0.1 mW/mm ² to 10 W/mm ² . The entire insect warming region 300 may have an energy density of the maximum value. A portion of the insect temperature raising region 300 may have the maximum energy density as long as it is within a range that prevents insects from entering the second space 200 . For example, the portion of the insect heating region 300 where the energy density is the maximum value may be the portion of the insect heating region 300 adjacent to the second space 200 .

The energy density in the insect temperature rising region 300 may be a calculated value or an actual measurement value. The energy density in the insect heating zone 300 can be determined by, for example, a power meter.

Furthermore, the waveform of the light emitted by the light source 11 may be a continuous wave or a pulse wave. Further, the light source 11 may include both a light source that emits continuous wave light and a light source that emits pulse wave light.

It is preferable for the light source 11 to emit intermittent light such as pulsed light from the viewpoint of reducing the effects on humans or animals. Examples of light sources 11 include lasers and flashlamps. Examples of lasers include semiconductor lasers, quantum cascade lasers, gas lasers, solid state lasers, fiber lasers and wavelength converted light sources. Examples of flashlamps include flashlamps that utilize electrical discharge.

A laser is suitable as a light source for either continuous wave or pulse wave light, is suitable as a light source for directly emitting the above infrared light, and is also suitable as a light source capable of emitting high-output light. preferred.

In the near-infrared region, there are many high-power semiconductor lasers developed for communication, and in the mid-infrared region, quantum cascade lasers developed for gas detection are rapidly spreading. Against this background, it becomes possible to easily use infrared light in the above wavelength range, which has been difficult to use. Furthermore, many high-intensity light sources in this wavelength range have been put to practical use in research, industry, and medical applications, and can be easily applied to this embodiment.

In particular, quantum cascade lasers are small, lightweight, and high-power. Therefore, it is suitable for mounting on drones or robots. This makes it possible to equip a moving body such as a drone with a light irradiation device that forms an insect heating area, which is suitable for repelling blood-sucking insects while tracking moving humans or animals.

A flash lamp emits light intermittently, and is therefore preferable from the viewpoint of reducing the effects on humans or animals.

Humans and animals differ greatly in heat capacity from insects. Therefore, when intermittent light or pulsed light is used, by selecting an appropriate light irradiation time and light intensity, the effects on humans and animals can be further suppressed, and the PT effect on insects can be suppressed. can be increased.

In particular, pulsed light can give high energy to insects in a short period of time. Therefore, it is suitable from the viewpoint of raising the temperature of insects in a short time. It takes a certain amount of time for heat radiation from the heated insect to the surrounding medium, the air. Therefore, heating in a short time is effective from the viewpoint of heat supply and heat release. For example, by emitting pulsed light or intermittent light with an irradiation time (pulse width) of 100 ms or less for a time within the thermal relaxation time of human skin, it is possible to achieve both a sufficient PT effect on insects and a reduction in the impact on humans. Is possible.

[Optical system]
The optical system 12 forms an insect temperature rising region 300 by irradiation of infrared light from the light source 11 . The optical system 12 has an optical configuration that can arbitrarily change the irradiation direction of light, and has an optical configuration that diffuses, converges, or scans the light from the light source 11 . The optical system 12 can be composed of known optical elements that converge, diverge, reflect, and refract light, and combinations thereof, and a known illumination optical system can be applied to the optical system 12 . For example, the optical system 12 is configured by appropriately arranging a cylindrical lens or a Powell lens, and it is possible to form a sheet-like space as the insect heating area 300 by irradiating light with such a configuration.

The optical system 12 may include a configuration for driving the optical element as required. For example, the light irradiation device 1 may have a scanning mechanism 22 as an optical system, as shown in FIG. The scanning mechanism 22 is a mechanism that temporally changes the irradiation direction of light. mirror) is mechanically moved at high speed.

Examples of scanning mechanism 22 include mechanical drives and electrical drives. Examples of mechanical drives include polygon mirrors, galvo mirrors and MEMS (Micro Electro Mechanical Systems) mirrors. Examples of electrical drivers include microstructures such as photonic crystals. The optical system including the scanning mechanism 22 can form a sheet-like (or curtain-like) space by irradiating light to a specific location and scanning the light.

The scanning mechanism 22 can illuminate any position in space at any time. Therefore, it is possible to form a virtual space (virtual volume) irradiated with light. In the virtual space, it is possible to arbitrarily divide the virtual space depending on the presence or absence of light irradiation. Therefore, in the virtual space, an arbitrary wavelength distribution and an arbitrary light intensity distribution of light can be spatio-temporally formed by irradiated light. Therefore, a plurality of portions irradiated with light with different wavelengths, a plurality of portions with different light intensities, a portion where the above-mentioned plurality of portions change continuously, or a combination thereof An insect heating zone 300 , can be formed by the scanning mechanism 22 .

Furthermore, the optical system 12 may optionally include a wavelength changing element such as a wavelength selective filter, a refractive index controlling element, or a polarization controlling element.

[Insect warming region]
The insect temperature raising region 300 is a region irradiated with infrared light having a wavelength of 1.4 μm to 3 mm so as to raise the temperature of insects. The insect temperature rising region 300 may be a region formed by irradiating a fixed position with infrared light, or may be a virtual space formed by scanning light as described above. Moreover, the shape of the insect heating area 300 is not limited as long as it is a shape corresponding to the second space 200 . For example, the shape of the insect heating region 300 may be a sheet shape or a substantially conical side surface shape.

The insect heating area 300 is located between the first space 100 and the second space 200 . The first space 100 is an area where insects such as mosquitoes 110 are present, for example outdoors. The second space 200 is a space that is not desired to be invaded by insects, such as an indoor space where humans 210 or pet animals live or work, or a barn where livestock live. In this case, the insect heating area 300 is a space that encloses or covers an opening in a building, such as a doorway or window that communicates between the indoors and outdoors.

The insect temperature raising region 300 is a region irradiated with infrared light so as to raise the temperature of insects. The insect temperature-raising region 300 may be a region where infrared light is constantly irradiated, so as to raise the temperature of insects that have invaded a specific region outside the second space 200 (for example, the aforementioned scanning It may be an area irradiated with infrared light.

The dimensions of the insect heating area 300 are within a range that can sufficiently raise the temperature of insects that have entered the insect heating area 300 from the first space 100 so as to change direction in the direction of returning to the first space 100 side. can be set as appropriate. For example, the more the infrared light forming the insect heating region 300 is absorbed by the insect, the more strongly the insect irradiates it, or the slower the insect moves, the smaller the dimension of the insect heating region 300. Is possible.

Also, the insect temperature raising region 300 may be formed by irradiating infrared light that works more strongly to raise the temperature of insects on the second space 200 side than on the first space 100 side. Irradiating infrared light so as to enhance the PT effect on insects on the second space 200 side is also effective from the viewpoint of reducing the dimensions of the insect temperature raising region 300 .

In this way, the size of the insect heating area 300 may be any length that the infrared light is applied to the insect for a time sufficient for the infrared light to heat the insect. It is possible to appropriately determine according to the amount of infrared light acting on. For example, the distance (thickness) between the first space 100 and the second space 200 in the insect heating area 300 should be 1 mm or more.

[Insects to avoid]
Insects to be repelled are not limited, but insects capable of transmitting infectious diseases to humans or animals are preferable from the viewpoint of improving hygiene problems of humans or animals. Examples of such insects include blood-sucking and flying insects, more particularly mosquitoes and flies. Examples of mosquitoes include Anopheles mosquito and Aedes albopictus.

Recent studies have revealed that mosquitoes have sensillum that expresses TRPA1 (trip A1) throughout their proboscis, thereby giving them the property of avoiding hot environments that adversely affect their survival. Recent studies have also revealed that the response threshold of TRPA1 differs for each mosquito species, and that mosquitoes that perform repellent behavior due to heat learn the danger zone. A mosquito 110 having such characteristics is suitable as an insect to be repelled by the light irradiation device 1 .

[Further configuration]
The light irradiation device 1 may further have other configurations than those described above as long as the effects of the embodiments of the present invention can be obtained.

For example, the light irradiation device 1 further includes a sensor for detecting the position of an insect (hereinafter also referred to as an "insect sensor"), and emits light from the light source 11 according to the detection result of the position of the insect by the insect sensor. An insect warming zone 300 may be formed.

Such a light irradiation device 1 can be realized by further providing a function of turning on/off the light source 11, turning on/off the scanning mechanism 22, or controlling the light scanning range of the scanning mechanism 22 according to the detection signal of the insect sensor. . A camera, for example, is used as the insect sensor. This configuration makes it possible to operate the light irradiation device 1 according to the presence of insects to be repelled. It is preferable from the viewpoint of further reducing the influence of light on humans or animals.

Further, for example, the light irradiation device 1 further includes an insect sensor, and further includes a position prediction unit for predicting the position of the insect with reference to the detection result of the position of the insect by the insect sensor. The insect temperature rising region 300 may be formed by emitting light from the light source 11 according to the prediction result.

For example, as described in Patent Document 3, the position of an insect is predicted by calculating a vector in the direction of movement of the insect from the position of the insect detected by an insect sensor at predetermined time intervals, and using the vector in the direction of movement to determine the position of the insect. It can be implemented by predicting flight direction. The position prediction unit may have any structure as long as it exhibits the function of calculating the flying direction from the detection value of the insect sensor. This configuration is preferable from the viewpoint of increasing the certainty of causing repelling behavior of insects in the insect temperature rising region 300 because it is possible to irradiate the insects with the light more efficiently, in addition to the labor saving of the light irradiation device 1 . .

In addition, for example, the light irradiation device 1 further includes a sensor for detecting the position of an animal other than humans or insects (hereinafter also referred to as an "animal sensor"), and according to the detection result of the position of the human or animal by the animal sensor, light from the light source 11 to form an insect heating zone 300 around a human or animal. In this case, the insect heating region 300 formed may be formed all around the human or animal, or may be formed only in a partial region around the human or animal.

Animal sensors can be electromagnetic wave sensors or cameras. Such a light irradiation device 1 can be realized by further including a function of controlling on/off of the light source 11 or on/off of the scanning mechanism 22 according to the detection signal of the animal sensor. This configuration is preferable from the viewpoint of labor saving of the light irradiation device 1 because the operation of the light irradiation device 1 is prevented when the object (human or animal) to be protected from insects is absent.

In the case of having an animal sensor, the light irradiation device 1 is advantageous to be mounted on a moving body. Mobile objects are primarily objects capable of tracking moving humans or animals, such as the aforementioned drones and robots. This configuration is suitable for outdoor use and provides an insect heating zone 300 for moving humans or animals.

[Experimental example]
Experimental examples regarding repelling behavior of insects irradiated with infrared light having a wavelength of 1.4 μm to 3 mm will be described below.

<Experimental example 1>
3 is a top view schematically showing the configuration of the experimental apparatus used in Experimental Example 1. FIG. FIG. 4 is a diagram schematically showing a cross section of the experimental apparatus taken along line AA in FIG. As shown in FIGS. 3 and 4, the experimental apparatus has a cell 30, a thermal camera 40, and a light source (not shown). The cell 30 is an elongated rectangular parallelepiped made of a transparent resin plate, and has mirrors 31 and 32 on both sides thereof. A window 34 opens at the upper edge of the central portion of the mirror 32 in the longitudinal direction.

The light source is a quantum cascade laser and emits light with a wavelength of 4.6 μm. The light source is arranged so that light is incident at a specific angle toward the opposite mirror 31 through the window 34 . More specifically, the laser beam from the light source is obliquely incident on the surface of the mirror 31 through the window 34, as shown in FIG. Thereby, the incident light is zigzag reflected between the mirrors 31 and 32 . This forms a simple virtual wall of light. The virtual wall corresponds to the insect repelling space described above. The portion of the virtual wall with the maximum value of the energy density is the portion near the window 34 in the cell 30, and the maximum value is about 100 mW/mm ² . Then, an adult (female) Aedes albopictus is confined in the cell 30 . The asterisks in the figure represent Aedes albopictus. Then, the inside of the cell 30 was photographed by the thermal camera 40, and the thermal camera 40 observed the temperature change when the Aedes albopictus in the cell 30 passed through the virtual wall. The results are shown in FIG.

In FIG. 5 , circles representing imaging time (seconds) and indicated by arrows in the figure represent light spots of Aedes albopictus detected by the thermal camera 40 . From FIG. 5, it can be seen that Aedes albopictus irradiated with light of wavelength 4.6 μm has a higher temperature than its surroundings. Since Aedes albopictus is a poikilotherm, it usually has a temperature about the same as the ambient temperature. From this experiment, it can be seen that the body temperature of mosquitoes can be increased by irradiating light with a wavelength of 4.6 μm.

FIG. 6 is a diagram showing an example of temperature changes of a specific Aedes albopictus in the above experimental apparatus. The horizontal axis of FIG. 6 represents the imaging time, and the vertical axis represents the temperature of Aedes albopictus. The temperature change of Aedes albopictus includes a relatively gentle rising portion and steep peaks of rapid rising and falling. The relatively gently rising portion represents the change in temperature of Aedes albopictus when resting on the wall of cell 30 . The sharp peaks represent changes in Aedes albopictus temperature when exposed to the rays that make up the virtual wall during flight. A portion with a low temperature indicates that Aedes albopictus is flying over a portion other than the virtual wall in the cell 30 .

According to FIG. 6, it can be seen that Aedes albopictus flies away from the environment where the temperature rises when the body temperature rises by a specific temperature or when the body temperature rises to about 30°C. Aedes albopictus is a mosquito widely distributed in Japan. According to the experimental results shown in FIG. 6, the threshold body temperature at which Aedes albopictus initiates the escape movement is estimated to be around 30°C.

FIG. 7 is a diagram showing an example of the results of observation by the thermal camera 40 of Aedes albopictus perched on the wall surface of the cell in the above experimental apparatus. In FIG. 7 , circles representing imaging time (seconds) and indicated by arrows in the figure represent light spots of Aedes albopictus detected by the thermal camera 40 . Moreover, FIG. 8 is a figure which shows an example of the temperature change of Aedes albopictus perched on the wall surface of a cell. The horizontal axis of FIG. 8 represents the imaging time, and the vertical axis represents the temperature of Aedes albopictus.

According to FIG. 7, the temperature of Aedes albopictus perched on the wall surface of the cell rises, and when the Aedes albopictus flies away, the temperature of Aedes albopictus drops, and the temperature-lowered Aedes albopictus again perches on the wall surface of the cell 30. Further, according to FIG. 8, the temperature of Aedes albopictus gradually rises while it is perched on the wall surface of the cell, and when it rises by about 3° C., it flies away, and as a result, the temperature of Aedes albopictus falls to the temperature before the rise. I know how to do it.

<Experimental example 2>
In an experimental system similar to Experimental Example 1, changes in temperature of Aedes albopictus were measured when Aedes albopictus was irradiated with light having a wavelength of 4.6 μm and a beam diameter of 2.5 mm with different irradiation intensities. The maximum temperature rise and the average temperature rise obtained from the measurement data for several minutes were obtained. The beam diameter was determined by the knife edge method. The results are shown in FIG. The horizontal axis of FIG. 9 represents the irradiation intensity, and the vertical axis represents the temperature of Aedes albopictus. In FIG. 9, the solid line represents the average temperature of Aedes albopictus measured, and the dashed line represents the maximum temperature of Aedes albopictus measured.

As is clear from FIG. 9, the temperature of Aedes albopictus becomes higher in proportion to the increase in the irradiation intensity of the irradiation light.

<Discussion>
According to the above experiment, when the body temperature of Aedes albopictus rose by 4 to 5°C, it was observed that Aedes albopictus tended to take action to escape from the environment in which such a temperature rise could occur.

In addition, most of the Aedes albopictus exposed to light in the experiment died the next day. From this, it is considered that Aedes albopictus is fatally damaged or stressed by the heat caused by the above light irradiation. For this reason, fatal damage to Aedes albopictus is not only thermal damage due to temperature rise, but also other secondary damage such as impact caused by photoacoustic waves generated when heat is converted into acoustic energy after temperature rise. It is possible that it is included.

According to literature, the temperature at which TRPA1 is activated differs depending on the type of mosquito, and is reported to be 21° C. for Culex pipiens and around 32° C. for Aedes aegypti, which is closely related to Aedes albopictus. Therefore, it is expected that the threshold temperature at which mosquitoes start escape movement due to light irradiation differs depending on the type of mosquito.

[Main effects]
The light irradiation device 1 according to the embodiment of the present invention irradiates a specific region with light (near infrared light and terahertz waves) having a wavelength of 1.4 μm to 3 mm to increase the temperature of insects in the region. warm up. Then, escape behavior is induced in insects that exceed the upper limit (threshold) of the temperature that is comfortable for the insect or the temperature that is safe for life support activities. Furthermore, by the action of photoacoustic waves due to temperature rise, escape behavior is induced by physical stimulation. In this way, the light irradiation device 1 irradiates insects with long-wavelength light corresponding to near-infrared light to terahertz waves, and utilizes the heat generation effect (PT effect) due to the light absorption of the insects for repelling behavior of the insects. ing.

Mosquitoes search for blood-sucking targets and sense environmental temperature by TRPA1. In particular, mosquitoes avoid environments where their body temperature exceeds a certain temperature. That is, by irradiating the mosquitoes with infrared light to generate heat due to light absorption, the mosquitoes can be made to recognize that the temperature is uncomfortable or dangerous, and can be made to escape from the place. Furthermore, in this embodiment, lethal heat damage or stress can be given to insects regardless of whether the insects (mosquitoes) respond to such infrared light irradiation.

That is, the present embodiment does not utilize the habits of individual insects (individuality, individual differences), but utilizes a factor that affects life support (here, heat), thereby exhibiting a high repelling effect. . By influencing the heat of insects, which is a factor directly linked to life support, a high insect repelling effect is realized. Therefore, it is possible to realize repelling that is not influenced by individual differences of insects. In addition, since no chemical is used in the present embodiment, resistance is less likely to occur in insects. Furthermore, since this embodiment does not depend on individual differences in insects, it is possible to more reliably repel insects than insect traps that use light or odor as an attractant.

In this embodiment, the infrared light illuminating the insect has a sufficiently long wavelength that it is invisible to humans or animals. For example, the maximum permissible exposure of human eyes to light having a wavelength of 1.4 μm or more is at least two orders of magnitude higher than that of visible light and near-infrared light having a wavelength of several hundred nm, The maximum permissible exposure time is at least four orders of magnitude higher. Moreover, since the insect temperature rising region 300 is a region formed by irradiation with infrared light, there is no physical obstacle between the second space 100 and the first space 200 . Therefore, according to this embodiment, the landscape and the flow line of humans or animals are ensured while preventing insects from approaching. As described above, the present embodiment has substantially no effect on humans or animals, and is highly effective in repelling insects. Therefore, it is expected to be used in a wider range of fields than conventional insect repelling techniques.

In addition, in this embodiment, for example, the scanning mechanism 22 can form the insect heating region 300 as a three-dimensional light virtual space. Therefore, it is possible to ensure the action time of the infrared light that brings about a sufficient PT effect on insects. In addition, by giving an arbitrary distribution or gradient to the intensity or wavelength of the infrared light in the insect temperature rising region 300, it is possible to prevent insects from entering the second space 200 more strongly.

For example, when an infrared light intensity gradient is formed in the insect heating area 300, the insects in the insect heating area 300 are gradually subjected to the PT effect at first, and the PT effect is stronger at a certain point. Therefore, insects are more likely to move in the direction of low light intensity due to such enhancement of the PT effect. That is, insects are more easily prevented from entering the second space 200 .

As for the wavelength of the infrared light, for example, a higher insect repelling effect can be expected by selecting light in the wavelength band of 6 to 7 μm, which is more absorbed by the chitin or wax component of insects. In particular, it is more effective when targeting insects, such as mosquitoes and flies, which are regarded as flying pests.

[Use]
The light irradiation device according to the embodiment of the present invention can be applied to openings (entrances, windows) in public buildings such as schools and hospitals, and can be applied to insect repellents in the buildings. Moreover, the light irradiation device according to the embodiment of the present invention can be applied to the opening of a livestock barn or cage, and can be applied to repel insects to animals in these.

Furthermore, by mounting it on a moving body such as a drone or by supporting it at the tip of a support, it can also be applied to insect repellent for humans or animals at any outdoor location.

[Other embodiments]
In the embodiment of the present invention, the insect heating area 300 is formed by the light source 11 and the optical system 12, but may be formed by direct irradiation of infrared light from a multi-point light source in which a plurality of light sources are arranged.

An embodiment of the present invention is a device for controlling the speed of movement of insects, for example, generating an airflow from an insect heating zone toward a first space to reduce the approach speed of flying insects to the second space. It may further have an airflow generator that causes the airflow to flow. This configuration is preferable from the viewpoint of increasing the insect repelling effect because it is possible to lengthen the residence time of insects traveling from the first space to the second space in the insect temperature rising region.

Embodiments of the present invention may further include a sensor that detects other conditions related to the speed of movement of the insect, and further refer to the detection result of the sensor to form the insect temperature elevation region. For example, in the case of flying insects, examples of such sensors include an anemometer. When there is a wind in the direction from the insect heating area to the second space, the movement speed of the flying insects becomes faster, and the insect heating area from the first space to the second space increases. It is conceivable that the residence time of In this case, infrared light is irradiated with a higher irradiation intensity to form the insect temperature rising region. This configuration is preferable from the viewpoint of suppressing fluctuations in the insect repelling effect due to disturbance.

〔summary〕
As is clear from the above description, the light irradiation device (1) according to the embodiment of the present invention prevents insects (mosquitoes 110) from entering the second space (200) from the first space (100). In order to prevent this, an insect heating area (300) is formed between the first space and the second space to raise the temperature of insects by irradiating light having a wavelength of 1.4 μm or more and 3 mm or less. Therefore, the light irradiation device can suppress the influence on humans or animals in repelling insects by light irradiation, and can increase the certainty of repelling insects.

In an embodiment of the present invention, the maximum value of the light energy density in the insect warming region is 0.01 nJ/mm ² or more and 10 J/mm ² or less, or the maximum average light power density in the insect warming region The value may be 0.1 mW/mm ² or more and 10 W/mm ² or less. This configuration is much more effective from the viewpoint of increasing the certainty of repelling behavior of insects.

The light irradiation device may have a laser or a flash lamp as light source (11). This configuration is much more effective from the viewpoint of reducing the effects on humans or animals and from the viewpoint of enhancing the PT effect on insects.

The light irradiation device may further include a scanning mechanism (22) that changes the irradiation direction of light. This configuration is much more effective from the viewpoint of forming various forms of insect warming regions.

The light irradiation device may further include a sensor for detecting the position of the insect, and irradiate light according to the detection result of the position of the insect by the sensor to form the insect temperature rising region. This configuration is more effective from the viewpoint of saving the power of the light irradiation device and further reducing the influence of the light that forms the insect temperature rising region on humans or animals.

The light irradiation device further includes a sensor that detects the position of the insect, and further includes a position prediction unit that predicts the position of the insect with reference to the detection result of the position of the insect by the sensor. The insect temperature rising region may be formed by irradiating light according to the prediction result. This configuration is much more effective from the viewpoint of increasing the certainty of causing the insects to take a repelling action.

The light irradiation device may further include an airflow generator that generates an airflow from the insect temperature rising region toward the first space to reduce the approach speed of the flying insects to the second space. . If the light irradiation device further has a device for controlling the speed of movement of the insects, it is possible to repel the insects by extending the residence time of the insects moving from the first space to the second space in the insect temperature rising region. It is much more effective from the viewpoint of enhancing the effect.

The light irradiation device may further include a sensor that detects other states related to the moving speed of the insect, and further refer to the detection result of the sensor to form the insect temperature rising region. This configuration is more effective from the viewpoint of suppressing fluctuations in the repelling effect of insects due to disturbances, since an insect temperature rise region is formed in which behavior of insects under other conditions is reflected.

The light irradiation device further has a sensor for detecting the position of humans or animals other than insects, and irradiates light according to the detection result of the position of humans or animals by the sensor to increase the temperature of insects around humans or animals. A region may be formed. This configuration is much more effective from the viewpoint of labor saving of the light irradiation device.

The light irradiation device may be mounted on a moving body. This configuration is even more effective from the viewpoint of preventing disease infection by insects outdoors, since it is possible to appropriately form an insect temperature rising region even for moving humans or animals.

In an embodiment of the invention, the insect may be one or more insects selected from the group consisting of mosquitoes and flies. This configuration is even more effective from the standpoint of preventing transmission of infectious diseases to humans or animals by insects.

According to the above-described embodiments of the present invention, more reliable chemical-free insect control against pests that carry epidemics is possible. Therefore, the present invention is expected to contribute to the achievement of Sustainable Development Goals (SDGs) related to minimizing the release of chemical substances, securing healthy lives and promoting welfare of people, and maintaining the natural environment.

The present invention is not limited to the above-described embodiments, and various modifications are possible within the scope of the claims. Embodiments obtained by appropriately combining technical means disclosed in different embodiments are also included in the technical scope of the present invention.

1 light irradiation device 11 light source 12 optical system 22 scanning mechanism 30 cell 31, 32 mirror 34 window 40 thermal camera 100 first space 110 mosquito 200 second space 210 human 300 insect heating area

Claims (11)

Irradiation of light having a wavelength of 1.4 μm or more and 3 mm or less between the first space and the second space in order to prevent insects from entering the second space from the first space A light irradiation device that forms an insect heating area that raises the temperature of insects by The maximum value of the energy density of the light in the insect heating region is 0.01 nJ/mm ² or more and 10 J/mm ² or less, or the maximum value of the average power density of the light in the insect heating region is 0. .1 mW/mm ² or more and 10 W/mm ² or less. 3. The light irradiation device according to claim 1, which has a laser or a flash lamp as a light source. 4. The light irradiation device according to any one of claims 1 to 3, further comprising a scanning mechanism for changing the irradiation direction of said light. further having a sensor for detecting the position of the insect;
5. The light irradiation device according to any one of claims 1 to 4, wherein the light is irradiated to form the insect temperature rising region according to the detection result of the position of the insect by the sensor. further comprising a sensor for detecting the position of the insect, and a position prediction unit for predicting the position of the insect by referring to the result of detection of the position of the insect by the sensor;
5. The light irradiation device according to any one of claims 1 to 4, wherein the light is irradiated according to the prediction result of the position of the insect by the position prediction unit to form the insect temperature rising region. 7. The method according to any one of claims 1 to 6, further comprising an airflow generating device that generates an airflow from the insect heating area toward the first space to reduce the approach speed of flying insects to the second space. The light irradiation device according to any one of the items. further comprising a sensor for detecting other conditions related to the speed of movement of the insect;
The light irradiation device according to any one of claims 1 to 7, wherein the insect temperature rising region is formed by further referring to the detection result of another state by the sensor. further having a sensor for detecting the position of an animal other than humans or insects;
The light according to any one of claims 1 to 8, wherein the light is emitted according to the detection result of the position of the human or animal by the sensor to form the insect warming region around the human or animal. Irradiation device. The light irradiation device according to claim 9, which is mounted on a moving object. The light irradiation device according to any one of claims 1 to 10, wherein the insects are one or more insects selected from the group consisting of mosquitoes and flies.

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