Light source device, light reflecting member, and light-transmissive member

Abstract

To provide a light source device, a light reflecting member and a translucent member capable of controlling an insect attracting effect.SOLUTION: The light source device radiates light that excites only one visual cell or excites a plurality of visual cells including visual substances having absorption wavelength bands in which absorption peaks are adjacent to each other, among a plurality of types of visual cells constituting a part of an eye of an insect that includes visual substances having different absorption wavelength bands that are wavelength bands of light to be absorbed and is excited when light is absorbed by the visual substances. A difference absolute value between a maximum intensity of a peak portion and a minimum intensity of a valley portion of an optical spectrum of light emitted from the light source device in an absorption wavelength band of a visual pigment contained in the plurality of visual cells is 40% or less of the maximum intensity of the optical spectrum.SELECTED DRAWING: Figure 8

Description

[Technical Field]

[0001] The present invention relates to a light source device, a light reflecting member, and a light-transmitting member. [Background technology]

[0002] A lighting system has been proposed that includes two types of light sources that emit light with different spectral power distributions, and by setting the spectral power distribution of the light emitted from one of the light sources to have a higher insect attracting effect than that of the other light source, it is possible to attract and retain insects to one of the two light sources, thereby reducing the discomfort caused to people near the other light source (see, for example, Patent Document 1). [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Special Publication No. 2017-509321 Summary of the Invention [Problem to be solved by the invention]

[0004] Incidentally, in a lighting system such as that described in Patent Document 1, when selecting between two types of light sources, it is necessary to understand the difference between the spectral power distribution of light that has a relatively high insect attracting effect and the spectral power distribution of light that has a relatively low insect attracting effect. Therefore, the inventors clarified the difference between the spectral power distribution of light that has a relatively high insect attracting effect and the spectral power distribution of light that has a relatively low insect attracting effect, and realized a light source device, a light-reflecting member, and a light-transmitting member that can achieve an insect attracting effect with high accuracy.

[0005] The present invention has been made in view of the above circumstances, and has an object to provide a light source device, a light reflecting member, and a light-transmitting member that can control the insect attracting effect. [Means for solving the problem]

[0006] In order to achieve the above object, a light source device according to the present invention comprises: Of the multiple types of photoreceptors that make up part of an insect's eye, which contain visual pigments with different absorption wavelength bands, which are the wavelength bands of light that they absorb, and which become excited when light is absorbed by the visual pigments, only one photoreceptor cell is excited, or light is emitted that excites multiple photoreceptor cells that contain visual pigments with absorption wavelength bands whose absorption peaks are adjacent to each other. [Effects of the Invention]

[0007] According to the present invention, light is emitted that excites only one of the multiple types of photoreceptor cells that make up part of an insect's eye, or that excites multiple photoreceptor cells containing visual pigments with absorption wavelength bands whose absorption peaks are adjacent to each other, thereby controlling the insect attraction effect. [Brief explanation of the drawings]

[0008] [Figure 1A] Schematic diagram of an insect. [Figure 1B] FIG. 1 is a schematic diagram showing the multiple image eyes of an insect. [Figure 2A] Schematic diagram of an insect ommatidium. [Figure 2B] FIG. 2B is a cross-sectional view of an insect ommatidium taken along line AA in FIG. 2A. [Figure 3] FIG. 1 is a diagram showing the absorption wavelength bands of visual pigments contained in each of the photoreceptor cells that make up part of an insect's eye. [Figure 4A] This is a photo of the appearance of morning glory. [Figure 4B] FIG. 1 is a diagram showing the reflected light spectrum of the petals of Mirabilis mirabilis. [Figure 5] FIG. 1 is a diagram showing the reflected light spectrum of a leaf portion of Mirabilis mirabilis. [Figure 6A] This is a photo of the appearance of a cuckoo. [Figure 6B] FIG. 1 is a diagram showing the reflected light spectrum of the petals of a lesser cuckoo flower. [Figure 7] FIG. 1 is a diagram showing the reflected light spectrum of the leaves of a lesser cuckoo. [Figure 8] FIG. 1 is a diagram showing the optical spectrum of light that has an insect attracting effect. [Figure 9] Schematic diagram of an insect's compound eye. [Figure 10A] Schematic diagram of an insect ommatidium. [Figure 10B] FIG. 10 is a schematic diagram showing a case where the distance between the target and the eye is relatively short. [Figure 10C] FIG. 10 is a schematic diagram showing a case where the distance between the target and the eye is relatively long. [Figure 11] 5A and 5B are diagrams showing the optical spectra of light emitted from the light source devices according to the examples and comparative examples of the first embodiment. [Figure 12] FIG. 10 is a diagram showing an example of the optical spectrum of light in which the insect attracting effect is significantly reduced according to the second embodiment. [Figure 13A] This is a photo of the appearance of oleander. [Figure 13B] FIG. 1 is a diagram showing the reflected light spectrum of oleander petals. DETAILED DESCRIPTION OF THE INVENTION

[0009] (Embodiment 1) Hereinafter, an embodiment of the present invention will be described with reference to the accompanying drawings. A light source device according to this embodiment emits light that causes a lower excitation level of at least one photoreceptor cell containing a visual pigment having an absorption wavelength band with an absorption peak between the absorption peaks of two absorption wavelength bands than that of a photoreceptor cell containing a visual pigment having two absorption wavelength bands with absorption peaks spaced apart, among multiple types of photoreceptors that make up part of the eye of an insect, which contain visual pigments with different absorption wavelength bands that are absorbed by the visual pigments and become excited (polarized) when the visual pigments absorb light.

[0010] Here, the structure of insect eyes, which is the premise of the present invention, will be described. Insects IN having compound eyes CE as shown in FIG. 1A include, for example, a compound eye CE1 formed by a group of multiple ommatidia as shown in FIG. 1B. The compound eye CE1 includes multiple corneas CU, one cone CR for each of the multiple corneas CU, photoreceptor cells RE on the side of the cone CR opposite the cornea CU, and an optic nerve NO connected to the photoreceptor cells RE. The multiple photoreceptor cells RE are arranged to surround the optical axis of a lens system consisting of a pair of corneas CU and cones CR. Each of the multiple photoreceptor cells RE contains a visual pigment with a different absorption wavelength band, which is the wavelength band of light that it absorbs. For example, as shown in FIG. 2A, photoreceptor cells RE_L, RE_M, and RE_S are arranged so that their visual pigment-containing portions P_L, P_M, and P_S, each containing a visual pigment, are adjacent to each other, thereby forming a rhabdom (photoreceptor site) RH consisting of the visual pigment-containing portions P_L, P_M, and P_S.

[0011] As shown in Figure 2B, the rhabdome RH is formed adjacent to the lens system consisting of the cornea CU and the cones CR. Each of these visual pigment-containing regions P_L, P_M, and P_L has a structure with numerous protruding microvilli, and these microvilli contain visual pigments. The rhabdome RH has a higher refractive index than the rest of the visual pigment-containing regions P_L, P_M, and P_S of the photoreceptor cells RE, and functions as an optical waveguide for light entering the rhabdome RH from the lens system consisting of the cornea CU and the cones CR. Therefore, as shown by the arrow Li in Figure 2B, light entering the rhabdome RH from the lens system consisting of the cornea CU and the cones CR propagates within the rhabdome RH. Note that some insects IN have overlapping eyes, in which a transparent layer is interposed between the lens system consisting of multiple corneas CU and multiple cones CR and the photoreceptor cells RE.

[0012] Furthermore, the photoreceptor cells RE_L, RE_M, and RE_S each have a visual pigment-containing portion P_L, P_M, and P_S, respectively, which contain visual pigments with different absorption wavelength bands, which are wavelength bands of light that they absorb. In the photoreceptor cell RE_L, for example, as shown by the curve S_L in Fig. 3, a visual pigment-containing portion P_L containing a visual pigment with an absorption wavelength band of 450 nm to 700 nm is formed. In the photoreceptor cell RE_M, for example, as shown by the curve S_M in Fig. 3, a visual pigment-containing portion P_M containing a visual pigment with an absorption wavelength band of 350 nm to 550 nm is formed. In addition, in the photoreceptor cell RE_S, for example, as shown by the curve S_S in Fig. 3, a visual pigment-containing portion P_S containing a visual pigment with an absorption wavelength band of 300 nm to 400 nm is formed. The RE_L photoreceptor cells are excited when the visual pigment absorbs light in the wavelength range of 450 nm to 700 nm, and the RE_M photoreceptor cells are excited when the visual pigment absorbs light in the wavelength range of 350 nm to 550 nm.The RE_L photoreceptor cells are also excited when the visual pigment absorbs light in the wavelength range of 450 nm to 700 nm.

[0013] Based on the above, the inventors investigated the reflected light spectra of flowers that attract insects in nature. When the reflected light spectra were measured for light reflected from five locations on the petals of a Mirabilis flower (Figure 4A), reflected light spectra S11, S12, S13, S14, and S15 were obtained, as shown in Figure 4B. The intensity in the wavelength range of 500 to 600 nm was lower than the intensity in the wavelength ranges around 400 nm and 650 nm or higher. Furthermore, when the reflected light spectra were measured for light reflected from four locations on the leaves of Mirabilis flower (Figure 4A), reflected light spectra S16, S17, S18, and S19 were obtained, as shown in Figure 5. These spectra have a lower contrast between the intensity in the wavelength range of 500 to 600 nm and the intensity in the wavelength ranges around 400 nm and 650 nm or higher, compared to the petals. Furthermore, when the reflected light spectrum was measured for light reflected from each of five locations on the petals of the lesser cuckoo shown in Figure 6A, reflected light spectra S21, S22, S23, S24, and S25 were observed, as shown in Figure 6B, in which the intensity in the wavelength region around 550 nm was lower than the intensity in the wavelength regions around 450 nm and 650 nm or above. Furthermore, when the reflected light spectrum was measured for each of six locations on the leaves of the lesser cuckoo shown in Figure 6A, reflected light spectra S26, S27, S28, S29, S30, and S31 were observed, as shown in Figure 7, in which the contrast between the intensity in the wavelength region around 550 nm and the intensity in the wavelength regions around 450 nm and 650 nm or above was lower than that of the petals. These results indicate that insects are attracted to flowers that reflect light with a reflected light spectrum that has peaks on both the long and short wavelength sides, in other words, a valley where the intensity is low. Specifically, we found that insects are more likely to be attracted to flowers that reflect light with a reflected light spectrum in which the sum of the intensities of the components corresponding to the absorption wavelength band of 300 nm or more and 400 nm or less of the visual pigment contained in photoreceptor cell RE_S and the sum of the intensities of the components corresponding to the absorption wavelength band of 450 nm or more and 700 nm or less of the visual pigment contained in photoreceptor cell RE_L are greater than the sum of the intensities of the components corresponding to the absorption wavelength band of 350 nm or more and 550 nm or less of the visual pigment contained in photoreceptor cell RE_M.Furthermore, since insects tend to be attracted to the petals of flowers more than the leaves, it was found that the greater the contrast in intensity, the more likely insects are to be attracted.

[0014] From this, the inventors have found that a light source that emits light having a spectral spectrum in which the sum of the intensities of the components corresponding to the absorption wavelength band of 300 nm to 400 nm of the visual pigment contained in the photoreceptor cell RE_S and the sum of the intensities of the components corresponding to the absorption wavelength band of 450 nm to 700 nm of the visual pigment contained in the photoreceptor cell RE_L are greater than the sum of the intensities of the components corresponding to the absorption wavelength band of 350 nm to 550 nm of the visual pigment contained in the photoreceptor cell RE_M. That is, as shown in Figure 8, the inventors have found that a light source that emits light having a spectral spectrum with intensity peaks in the wavelength bands of 300 nm to 400 nm and 450 nm to 700 nm and with a valley where the intensity drops in the wavelength band of 350 nm to 550 nm has a high insect attracting effect.

[0015] In a multiple-image eye or a double-image eye, light incident from a target relatively far from the eye is incident on one or a few ommatidium. In particular, in the case of a double-image eye, light incident on multiple ommatidium is incident on one or a few rhabdoms. In this case, if the rhabdoms are composed of photoreceptors that excite light of different wavelength bands, information about the wavelength of light is retained, allowing discrimination of the wavelength of light. However, spatial information, such as the shape of the target or the distance to the target, is lost. For example, as shown in Figure 9, the spatial discrimination of insects is determined by both the angular sensitivity A11 of the ommatidium and the inter-ommatidial angle ΔΦ. As shown in Figure 10A, the angular sensitivity of each ommatidium is 1 to 2 degrees. As shown in Figure 10B, when an insect is close to a flower, multiple ommatidium individually receive light, allowing it to perceive spatial information, distinguish the flower's shape, and improve wavelength discrimination. In other words, for targets near the insect, shape information and wavelength discrimination information can be obtained. On the other hand, as shown in Figure 10C, when an insect moves away from a flower, only one or a few ommatidia can receive light due to the influence of the ommatidia's angular sensitivity A11 and ommatidia's angle A12. This results in the loss of shape information. For targets located far away from the insect, the visible range is determined by the angular sensitivity A11 of each ommatidia and the interommatidia angle A12. In multiple-image eyes, only one or at most a few ommatidia receive light, so shape information is lost. In overlapping-image eyes, light incident on the corneas of many ommatidia is focused on the rhabdom of a single ommatidia. Because that single rhabdom receives light from the outside world, shape information is lost. To survive and distinguish targets from backgrounds in the absence of shape information, insects are thought to have evolved to distinguish targets using wavelength contrast information, i.e., spectral valleys. From this, it is highly likely that flowers that are effective in attracting insects reflect light with a wavelength-dependent reflected light spectrum as described above, that is, light with contrast in intensity due to differences in wavelength, thereby stabilizing information acquisition for insects.In other words, due to the structure of their eyes, insects are unable to recognize the shape of targets that are located relatively far away, and it is thought that the waveform information that enters the ommatidia, i.e., the spectral information, acts as a trigger for attraction behavior.

[0016] A light source device according to the present embodiment was invented based on this finding and emits light that excites at least one photoreceptor cell having an absorption wavelength band with an absorption peak between the absorption peaks of two absorption wavelength bands, which are among the multiple types of photoreceptor cells constituting a part of an insect's eye, to a lower degree than the excitation of photoreceptor cells having a visual pigment with two absorption wavelength bands with widely separated absorption peaks. This light source device includes, for example, at least one light-emitting unit that emits light that excites photoreceptor cells having a visual pigment with an absorption wavelength band on the shorter side of the two absorption wavelength bands with widely separated absorption peaks, and a light converting member that converts the light emitted from the at least one light-emitting unit into light that excites photoreceptor cells having a visual pigment with an absorption wavelength band on the longer side of the two absorption wavelength bands with widely separated absorption peaks. Here, the at least one light-emitting unit emits light having a spectrum with a maximum intensity in a wavelength band of 300 nm to 400 nm, for example. The light conversion member may be, for example, translucent and excited by light emitted from at least one light-emitting unit to emit light having a spectrum with a maximum intensity in a wavelength band of 460 nm to 700 nm. Preferably, the light emitted from the light source device has an absolute difference between the maximum intensity at the peak and the minimum intensity at the valley of the spectrum that is greater than 40% of the maximum intensity of the spectrum. The light source device may include, for example, a light-emitting unit that emits light that excites only photoreceptor cells containing visual pigments having an absorption wavelength band on the shorter side of the two absorption wavelength bands whose absorption peaks are spaced apart, and a light-emitting unit that emits only light that excites photoreceptor cells containing visual pigments having an absorption wavelength band on the longer side of the two absorption wavelength bands whose absorption peaks are spaced apart, arranged closely to each other. Specifically, for example, the light source device may be one in which a light emitting unit that emits light having a spectrum whose intensity is greatest in a wavelength band of 300 nm or more and 400 nm or less, and a light emitting unit that emits light having a spectrum whose intensity is greatest in a wavelength band of 460 nm or more and 700 nm or less, are arranged closely to each other.

[0017] Here, we will explain the results of comparing the insect capture amounts of insect traps using light source devices according to an example and a comparative example. The light source device used in the comparative example emits light with a unimodal spectrum, with a peak only in the ultraviolet wavelength range with a peak wavelength of 367 nm. Meanwhile, the light source device used in the example of the present invention emits light with a bimodal spectrum, with peaks in relative intensity in the ultraviolet wavelength range of 367 nm and at 519 nm. The spectral spectra of light emitted from the light source devices according to the example and the comparative example are shown in Figure 11. In Figure 11, curve S41 represents the spectral spectrum of light emitted from the light source device according to the comparative example, and curve S42 represents the spectral spectrum of light emitted from the light source device according to the example. Insect traps using the light source devices according to the example and the comparative example were installed near the riverbed of the Katsura River in Kyoto City and left with the light source devices of each trap turned on from June 11, 2021, to June 27, 2021. Table 1 below shows the insect capture amounts of insects captured when the light source devices of each insect trap were left on.

[0018] [Table 1]

[0019] As shown in Table 1, it was found that the amount of insects captured by an insect trap using the light source device according to the example was greater than the amount of insects captured by an insect trap using the light source device according to the comparative example. From this result, it is found that a higher insect catching effect can be obtained by using a light source device that emits light having a bimodal spectrum with peaks of relative intensity not only in the ultraviolet wavelength band but also in the wavelength band of 460 nm to 640 nm, as in the light source device according to the example.

[0020] In conclusion, the light source device according to this embodiment emits light that excites at least one photoreceptor cell having a photoreceptor pigment with an absorption wavelength band whose absorption peak is between the absorption peaks of two absorption wavelength bands less than the excitation level of photoreceptor cells having a photoreceptor pigment with two absorption wavelength bands whose absorption peaks are spaced apart from each other, among multiple types of photoreceptor cells. This allows for a highly reliable insect attracting effect.

[0021] (Embodiment 2) The light source device according to the present embodiment was invented based on the findings described in the first embodiment and emits light that excites only one of multiple types of photoreceptors that constitute a part of an insect's eye, each of which contains visual pigments with different absorption wavelength bands that absorb light and become excited when the visual pigments absorb light. Alternatively, the light source device emits light that excites multiple photoreceptors containing visual pigments with absorption wavelength bands whose absorption peaks are adjacent to each other. The light source device may, for example, emit light that excites multiple photoreceptors containing visual pigments with absorption wavelength bands whose absorption peaks are adjacent to each other, and in which the absolute difference between the maximum intensity of the peaks and the minimum intensity of the valleys in the absorption wavelength bands of the visual pigments contained in the multiple photoreceptors is 40% or less of the maximum intensity of the spectral spectrum. For example, the spectral spectrum of the light emitted from the light source device may have a wavelength band from 340 nm to 700 nm inclusive in which the absolute difference between the maximum intensity of the peaks and the minimum intensity of the valleys is 40% or less of the maximum intensity of the spectral spectrum. Preferably, the light source device emits light such that the absolute difference between the maximum intensity and the minimum intensity in the wavelength band of 430 nm to 630 nm is 25% or less of the maximum intensity, as shown in FIG.

[0022] The inventors have also discovered that among flowers that exist in nature and that attract insects, there are flowers that appear white. Therefore, they investigated the reflected light spectra of these insect-attracting flowers that appear white. When the reflected light spectra of light reflected from five locations on the petals of an oleander (shown in FIG. 13A) were measured, reflected light spectra S51, S52, S53, S54, and S55 were measured, as shown in FIG. 13B, in which the intensity in the wavelength range of 400 nm or more is higher than the intensity in the wavelength range of less than 400 nm. These results indicate that insects are also attracted to flowers that reflect light with a reflected light spectrum similar to the light spectrum of so-called white light, in which the intensity in the long wavelength range of 400 nm or more is high overall. Specifically, we found that insects are also more likely to be attracted to flowers that reflect light with a reflected light spectrum in which the sum of the intensities of the components corresponding to the absorption wavelength band of 450 nm to 700 nm of the visual pigment contained in photoreceptor cell RE_L and the sum of the intensities of the components corresponding to the absorption wavelength band of 350 nm to 550 nm of the visual pigment contained in photoreceptor cell RE_M are larger than the sum of the intensities of the components corresponding to the absorption wavelength band of 300 nm to 400 nm of the visual pigment contained in photoreceptor cell RE_S.

[0023] From this, the inventors have found that even a light source that emits light having a spectral spectrum in which the sum of the intensities of the components corresponding to the absorption wavelength band of 450 nm to 700 nm of the visual pigment contained in the photoreceptor cell RE_L and the sum of the intensities of the components corresponding to the absorption wavelength band of 350 nm to 550 nm of the visual pigment contained in the photoreceptor cell RE_M are greater than the sum of the intensities of the components corresponding to the absorption wavelength band of 300 nm to 400 nm of the visual pigment contained in the photoreceptor cell RE_S. In other words, the inventors have found that a light source that emits light having a spectral spectrum that has an intensity peak in the wavelength band of 350 nm to 550 nm and an adjacent intensity peak in the wavelength band of 450 nm to 700 nm, and has a portion where the intensity drops in the wavelength band of 300 nm to 400 nm, is highly effective at attracting insects.

[0024] In order to reduce the discomfort felt by people near the light source device, a light source device that significantly reduces the insect attractant effect with high accuracy is required. In response to this, the light source device according to this embodiment emits light that excites only one of the multiple types of photoreceptors that make up part of an insect's eye, each of which contains visual pigments with different absorption wavelength bands, or light wavelength bands that are absorbed by the visual pigments, and that are excited when light is absorbed by the visual pigments. Alternatively, the light source device emits light that excites multiple photoreceptors containing visual pigments with absorption wavelength bands whose absorption peaks are adjacent to each other. This significantly reduces the insect attractant effect.

[0025] Although the above describes each embodiment of the present invention, the present invention is not limited to the configuration of each of the above-described embodiments. For example, the light-reflecting member may be configured to reflect light that, when incident on the light, causes a lower level of excitation of at least one photoreceptor cell having a visual pigment with an absorption wavelength band whose absorption peak is between the absorption peaks of two absorption wavelength bands, compared to the excitation level of photoreceptor cells having a visual pigment with two absorption wavelength bands whose absorption peaks are spaced apart, among multiple types of photoreceptors that contain visual pigments with different absorption wavelength bands and are excited when the visual pigments absorb light. The reflecting member may be configured, for example, to have a first reflecting portion that reflects light that excites only photoreceptor cells having a visual pigment with an absorption wavelength band on the shorter side of the two absorption wavelength bands whose absorption peaks are spaced apart, and a second reflecting portion that reflects only light that excites photoreceptor cells having a visual pigment with an absorption wavelength band on the longer side of the two absorption wavelength bands whose absorption peaks are spaced apart, arranged closely to each other.

[0026] Furthermore, the light-reflecting member may be a light-reflecting member that reflects light that excites only one of multiple types of photoreceptors that make up part of an insect's eye, which contain visual pigments with different absorption wavelength bands, which are the wavelength bands of light that they absorb, when light is incident, or that excites multiple photoreceptors that contain visual pigments with absorption wavelength bands whose absorption peaks are adjacent to each other.

[0027] Furthermore, the light-transmitting member may be a member that transmits light that has a lower excitation level for at least one photoreceptor cell that includes a visual pigment having an absorption wavelength band with an absorption peak between the absorption peaks of two absorption wavelength bands than for a plurality of types of photoreceptor cells that include visual pigments having different absorption wavelength bands, which are wavelength bands of light that the visual pigments absorb, and that are excited when light is absorbed by the visual pigments. Note that the light-transmitting member may be, for example, a member that includes a first light-transmitting portion that transmits light that excites only photoreceptor cells that include a visual pigment having an absorption wavelength band with an absorption peak between the absorption peaks of two absorption wavelength bands, the absorption peaks of which are spaced apart, and a second light-transmitting portion that transmits only light that excites photoreceptor cells that include a visual pigment having an absorption wavelength band with a longer wavelength than the absorption peaks of two absorption wavelength bands, the absorption peaks of which are spaced apart, arranged closely to each other.

[0028] Alternatively, the light-transmitting member may transmit light that excites only one of multiple types of photoreceptors that contain visual pigments with different absorption wavelength bands, which are the wavelength bands of light that they absorb, and that are excited when light is absorbed by the visual pigments, or light that excites multiple photoreceptors that contain visual pigments with absorption wavelength bands whose absorption peaks are adjacent to each other.

[0029] Although the embodiments and modifications of the present invention have been described above, the present invention is not limited to these. The present invention includes any combination of the embodiments and modifications, and any combination to which appropriate modifications have been made.

[0030] This application is based on Japanese Patent Application No. 2023-061894, filed on April 6, 2023. The entire specification, claims and drawings of Japanese Patent Application No. 2023-061894 are incorporated herein by reference. [Industrial Applicability]

[0031] The light source device of the present invention is suitable as a light source device for preventing damage caused by insects. [Explanation of symbols]

[0032] CE: compound eye, CE1: optic eye, CR: cone, CU: cornea, NO: optic nerve, PL, PM, PS: visual pigment-containing areas, RE, REL, REM, RES: photoreceptor cells, RH: rhabdome

Claims

1. Among multiple types of photoreceptors constituting a part of an insect's eye, which contain visual pigments with different absorption wavelength bands, which are wavelength bands of light that they absorb, and which become excited when light is absorbed by the visual pigments, only one photoreceptor cell is excited, or the insect emits light that excites multiple photoreceptor cells containing visual pigments with absorption wavelength bands whose absorption peaks are adjacent to each other. Light source device.

2. The light source device excites a plurality of photoreceptor cells containing a visual pigment having absorption wavelength bands whose absorption peaks are adjacent to each other, and emits light such that the absolute value of the difference between the maximum intensity of a peak portion and the minimum intensity of a valley portion of the spectrum of the light emitted from the light source device in the absorption wavelength bands of the visual pigment contained in the plurality of photoreceptor cells is 40% or less of the maximum intensity of the spectrum. The light source device according to claim 1 .

3. an absolute value of a difference between a maximum intensity of a peak portion and a minimum intensity of a valley portion in a wavelength band of 340 nm or more and 700 nm or less of the spectrum is 40% or less of the maximum intensity of the spectrum; The light source device according to claim 2 .

4. When light is incident, only one of the multiple types of photoreceptors constituting a part of an insect's eye is excited when the insect absorbs light by visual pigments that have different absorption wavelength bands, which are wavelength bands of light that the insect absorbs, or the insect reflects the exciting light, or the multiple photoreceptors that contain visual pigments with absorption wavelength bands whose absorption peaks are adjacent to each other reflect the exciting light. Light-reflecting material.

5. The insect transmits light that excites only one of a plurality of types of photoreceptors that constitute a part of the insect's eye, the photoreceptors including visual pigments with different absorption wavelength bands, which are wavelength bands of light that the insect absorbs, and that are excited when the visual pigments absorb light. Alternatively, the insect transmits light that excites a plurality of photoreceptors including visual pigments with absorption wavelength bands whose absorption peaks are adjacent to each other. Translucent member.

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