Light irradiation device

Abstract

To provide a light irradiation device capable of uniformly cauterizing a predetermined range of a biological tissue.SOLUTION: The light irradiation device comprises: a body part having a tubular part and a side wall provided at least on one end face of the tubular body; a first incident hole provided in the body part to allow external light to enter the inside of the body part; a long-sized first outgoing hole provided in the body part to allow the light having entered the inside of the body part to outgo to the outside; and a reflection part provided on the inner peripheral surface of the body part.SELECTED DRAWING: Figure 2

Description

[Technical field]

[0001] The present invention relates to a light irradiation device. [Background technology]

[0002] There are known devices for cauterizing biological tissue by irradiating light. For example, the device described in Patent Document 1 can cauterize biological tissue by irradiating light from a light source to one end of a rod-shaped light guide and irradiating light from the other end. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] U.S. Patent No. 6,530,919 Summary of the Invention [Problem to be solved by the invention]

[0004] However, when it is desired to uniformly cauterize a predetermined area of ​​biological tissue, it is difficult to do so with the device described in Patent Document 1.

[0005] An object of the present invention is to provide a light irradiation device capable of uniformly cauterizing a predetermined area of ​​living tissue. [Means for solving the problem]

[0006] The invention to achieve the above object is: A cylindrical portion having openings on both end surfaces as viewed in the direction of the central axis, and first and second side walls provided on each of the openings; The light irradiation device has a main body having a first entrance provided on the main body for allowing external light to enter the inside of the main body, a long first exit provided on the main body for emitting the light that has entered the inside of the main body to the outside, and a reflector provided on the inner circumferential surface of the main body. Other features of the present invention will become apparent from the description of the specification and drawings described below. Effect of the Invention

[0007] According to the present invention, a predetermined area of ​​living tissue can be uniformly cauterized. [Brief description of the drawings]

[0008] [Figure 1] FIG. 1 is a diagram for explaining a configuration of an illumination system according to a first embodiment. [Diagram 2] FIG. 2 is a cross-sectional view for illustrating the configuration of a light guide and a light irradiation device of the illumination system of the first embodiment. [Diagram 3] FIG. 2 is a cross-sectional view for illustrating the configuration of a light guide and a light irradiation device of the illumination system of the first embodiment. [Figure 4] FIG. 2 is a cross-sectional view for illustrating the configuration of a light guide and a light irradiation device of the illumination system of the first embodiment. [Diagram 5] FIG. 11 is a cross-sectional view for illustrating the configuration of a light guide and a light irradiation device of an irradiation system according to a second embodiment. [Figure 6] FIG. 2 is a diagram for explaining individual conditions of an example and a comparative example. [Figure 7] 13 shows the results of calculation of the illuminance distribution of light inside the light irradiation device in the example and the comparative example. [Figure 8] 13 shows calculation results of illuminance distribution of light at a first exit port in an example and a comparative example. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0009] First Embodiment ==Irradiation system== 1 is a diagram illustrating the configuration of an illumination system 1 according to the present embodiment. The illumination system 1 includes a light source device 2, a light guide 3, and a light illumination device 4.

[0010] [Light source device] The light source device 2 is a device that generates light for cauterizing biological tissue. The light source device 2 has a light source that generates light in a wavelength region that matches the light absorption / scattering characteristics of the tissue to be cauterized. Specifically, the light source is a laser light source, an LED light source, a halogen lamp, a xenon lamp, or the like, or light guided from the light source by a transmission means such as an optical fiber.

[0011] [Light guide] 2 to 4 are cross-sectional views for explaining the configuration of the light guide 3 and the light irradiation device 4 of this embodiment. In the following, an orthogonal coordinate system consisting of an x-axis, a y-axis, and a z-axis perpendicular to each other is used for explanation as shown in Figs. 2 to 4. Figs. 2, 3, and 4 are cross-sectional views of the light guide 3 and the light irradiation device 4 cut along an xy plane, a yz plane, and a zx plane passing through a center O of a main body 40 described later, respectively.

[0012] The light guide 3 is a member, such as an optical fiber, that propagates light from the light source device 2 to the light irradiation device 4. One end of the light guide 3 is connected to the light source device 2 (FIG. 1). The other end of the light guide 3 is connected to the light irradiation device 4 (FIGS. 1 to 4). The light incident on one end of the light guide 3 from the light source device 2 propagates through the light guide 3 and enters the inside of the light irradiation device 4.

[0013] In the following description, unless otherwise specified, the end of the light guide 3 on the light irradiation device 4 side will be simply called the "end". Furthermore, unless otherwise specified, the surface of the end of the light guide 3 from which the light from the light source device 2 exits will be called the "end surface 3a". In this embodiment, the end surface 3a of the light guide 3 has a flat shape.

[0014] [Light irradiation device] The light irradiating device 4 is a device that condenses the light from the light guide 3 and emits the light to the biological tissue to be cauterized. The light irradiating device 4 has a main body section 40 and a reflecting section 41.

[0015] (Main body) The main body 40 has a cylindrical portion 401 and a side wall portion 402 .

[0016] The cylindrical portion 401 is cylindrical. In the following description, the direction from one end of the cylindrical portion 401 to the other end is referred to as the "length direction of the cylindrical portion 401" or the "length direction of the main body portion 40." The length from one end of the cylindrical portion 401 to the other end is designated as L.

[0017] The tubular portion 401 of this embodiment has a cylindrical shape. When cut along a plane perpendicular to the longitudinal direction of the tubular portion 401, the cross section has a shape of a circle with a radius R.

[0018] 2 to 4, the central axis X1 of the cylindrical portion 401 is disposed parallel to the x-axis. The length direction of the cylindrical portion 401 coincides with the direction of the x-axis. In the following description, the center point of both ends of the cylindrical portion 401 on the central axis X1 is referred to as the "center O of the cylindrical portion 401" or the "center O of the main body portion 40."

[0019] The side wall portions 402 are provided on both end surfaces of the cylindrical portion 401. In this embodiment, the side wall portions 402 have a flat plate shape and are molded integrally with the cylindrical portion 401. Therefore, the shape of the inner peripheral surface of the main body 40 is the shape of the surface of a cylinder.

[0020] The main body 40 is provided with a first entrance 40a and a first exit 40b.

[0021] The first incident port 40a penetrates the main body 40 from the inner peripheral surface to the outer peripheral surface. The first incident port 40a is provided to allow light from the light guide 3 (end surface 3a) to enter the inside of the main body 40. The light from the light guide 3 corresponds to "external light." The first incident port 40a is provided on one of the side walls 402. In this embodiment, the first incident port 40a is provided at a position corresponding to the intersection of the side wall 402 and the central axis X1.

[0022] Specifically, the shape of the first entrance 40a is a circle having a predetermined radius. The first entrance 40a is disposed so that the central axis X1 passes through the center of the first entrance 40a. In this embodiment, the predetermined radius is equal to the radius of the light guide 3.

[0023] An end of the light guide 3 is inserted into the first entrance 40a, and the light irradiation device 4 and the light guide 3 are connected. This allows light from the light source device 2 to be emitted from the end face 3a of the light guide 3 and enter the inside of the main body 40. In this embodiment, the light guide 3 is connected to the light irradiation device 4 so that the end face 3a is perpendicular to the central axis X1.

[0024] In the following description, the side wall 402 on which the first entrance 40a is provided may be referred to as the "light source side side wall 402b." The other side wall 402 may be referred to as the "tip side side wall 402a." When there is no need to distinguish between the two, they will be collectively referred to simply as the "side wall 402."

[0025] The first emission outlet 40b is provided to emit light that has entered the inside of the main body 40 to the outside. In this embodiment, the light that has entered the inside of the main body 40 is light from the light source device 2 that has been emitted from the end face 3a of the light guide 3. The first emission outlet 40b is positioned at a site of biological tissue to be cauterized, and light is emitted from the first emission outlet 40b, thereby cauterizing the biological tissue.

[0026] The first light exit 40b has an elongated shape. In this embodiment, as shown in Fig. 4, the first light exit 40b has a shape in which the width in the long axis direction of the main body 40 is larger than the width in the short axis direction of the main body 40. The first light exit 40b has a rectangular shape having long sides parallel to the central axis X1 (Fig. 4).

[0027] The configuration of the main body 40 has been described above. In the present embodiment, the main body 40 has been described as having a structure in which the thickness (the distance between the inner peripheral surface and the outer peripheral surface) is constant, but this is not limiting. The main body 40 has a hollow portion, and as long as the shape of the surface of the hollow portion is the same as the shape of the surface of a cylindrical body, the thickness does not have to be constant.

[0028] In addition, in the present embodiment, the shape of the first emission opening 40b is rectangular, but is not limited thereto. The first emission opening 40b may be a shape other than rectangular. For example, the shape of the first emission opening 40b may be an ellipse, a rounded rectangle, or the like. In addition, in the present embodiment, the number of first emission openings 40b is one, but may be multiple.

[0029] In this embodiment, the cross-sectional shape of the main body 40 when cut along a plane (yz plane) perpendicular to the direction of the central axis X1 (x-axis direction) (hereinafter simply referred to as the "cross-sectional shape of the main body 40") is circular, but is not limited to this. The cross-sectional shape of the main body 40 may be polygonal, elliptical, or the like. For example, when the cross-sectional shape is rectangular, the tubular portion 401 has the shape of a cylindrical quadrangular prism.

[0030] The inside of the main body 40 may be sealed by filling the first light exit 40b with a transparent material. Alternatively, the inside of the main body 40 may be sealed by covering the first light exit 40b with a transparent material from the outer circumferential surface side or the inner circumferential surface side of the main body 40.

[0031] The reflecting portion 41 may be provided only on the cylindrical portion 401 and the side wall portion 402a on the tip side, and may not be provided on the side wall portion 402b on the light source side. The side wall portion 402 may be provided only on the side wall portion 402b on the light source side, without the side wall portion 402a on the tip side, and the end face on the tip side of the cylindrical portion 401 may be open.

[0032] (Reflector) The reflecting portion 41 is provided over the inner circumferential surface of the main body portion 40. That is, the reflecting portion 41 includes a portion provided on the inner circumferential surface of the cylindrical portion 401, an inner surface of the side wall portion 402a on the tip side, and an inner surface of the side wall portion 402b on the light source side.

[0033] The reflecting portion 41 is formed of a material that reflects light. When the light generated by the light source device 2 is in the visible light wavelength range, a metal material such as silver (Ag) or aluminum (Al) is used as the material that reflects light. When the light generated by the light source device 2 is in the infrared light wavelength range, a metal material such as gold (Au) is used as the material that reflects light. Although details will be described later, the reflecting portion 41 is formed of a material that provides the required reflectance depending on the height L of the cylindrical portion 401 and the radius R of the cylindrical portion 401 (or the cross-sectional area of ​​the cylindrical portion 401).

[0034] As one example, the reflecting portion 41 can be formed by coating the inner peripheral surface with a light reflecting material after forming the main body portion 40. As another example, before forming the main body portion 40, the reflecting portion 41 may be formed by coating the inner peripheral surface of the cylindrical portion 401 with a light reflecting material and coating one side surface of the flat side wall portion 402 with a light reflecting material.

[0035] The configuration of the irradiation system 1 of this embodiment has been described above. In this embodiment, the light source device 2 is provided outside the main body 40, and light from the light source device 2 is guided to the inside of the main body 40 via the light guide 3, but this is not limited to the above. For example, a light source element such as an LED element may be disposed inside the main body 40. In addition, the light guide 3 may further include a gripping portion at a predetermined distance from the light irradiation device 4 for an operator to grip with his / her hand when operating the irradiation system 1.

[0036] ==About the Propagation of Light== The light generated by the light source device 2 propagates through the light guide 3 and is emitted from the end face 3a of the light guide 3 (i.e., enters the inside of the main body 40 of the light irradiation device 4). At this time, the light traveling at various angles with respect to the end face 3a of the light guide 3 enters the inside of the main body 40.

[0037] A part of the light emitted from the end surface 3a of the light guide 3 propagates toward the side wall 402a on the tip side while repeatedly being reflected by the portion of the reflecting portion 41 formed on the cylindrical portion 401. The light that reaches the side wall 402a on the tip side is reflected by the portion of the reflecting portion 41 formed on the side wall 402a on the tip side, and propagates toward the side wall 402b on the light source side while repeatedly being reflected by the portion of the reflecting portion 41 formed on the cylindrical portion 401.

[0038] That is, the light inside the main body 40 propagates while repeatedly being reflected at the reflecting portion 41, unless it is emitted to the outside of the main body 40. At this time, the light inside the main body 40 travels back and forth between the side wall 402a on the tip side and the side wall 402b on the light source side in the longitudinal direction of the main body 40.

[0039] In this embodiment, the cylindrical portion 401 is translationally symmetric with respect to the length direction of the main body portion 40. Therefore, in the illuminance distribution of light inside the main body portion 40, the uniformity in the length direction of the main body portion 40 is higher than the uniformity in other directions.

[0040] A part of the light traveling inside the main body portion 40 reaches the first emission outlet 40b and is emitted from the first emission outlet 40b to the outside of the main body portion 40. The light emitted from the first emission outlet 40b can cauterize biological tissue.

[0041] In this embodiment, the first emission port 40b has an elongated shape having a length direction in the length direction of the main body 40. As described above, the illuminance of the light inside the main body 40 is highly uniform in the length direction of the main body 40. Accordingly, the illuminance of the light emitted from the first emission port 40b is also highly uniform. Therefore, according to the light irradiation device 4 of this embodiment, it is possible to cauterize biological tissue with highly uniform light.

[0042] It should be noted that the greater the length L of the cylindrical portion 401, the higher the frequency of reflection at the portion of the reflecting portion 41 provided on the inner circumferential surface of the cylindrical portion 401 inside the main body portion 40. Therefore, in order to suppress light loss inside the main body portion 40, the greater the length L of the cylindrical portion 401, the higher the reflectance must be at least at the portion of the reflecting portion 41 provided on the inner circumferential surface of the cylindrical portion 401. It should be noted that by forming the reflecting portion 41 by evaporating Ag (silver), a reflectance of about 96 to 98% can be obtained.

[0043] Furthermore, the larger the radius R of the cylindrical portion 401, the higher the frequency of reflection at the portion of the reflecting portion 41 provided on the surface of the side wall portion 402 inside the main body portion 40. Therefore, in order to suppress light loss inside the main body portion 40, the larger the radius R of the cylindrical portion 401, the higher the reflectance of at least the portion of the reflecting portion 41 provided on the surface of the side wall portion 402 needs to be.

[0044] Moreover, the side wall portion 402b on the light source side may not be provided, and one end face of the cylindrical portion 401 may be closed only by the end portion of the light guide 3. In this case, the cross-sectional shape of the cylindrical portion 401 may be made the same as that of the end face 3a.

[0045] <Second embodiment> 5 is a diagram illustrating the configuration of the light irradiation device 5 of this embodiment. The light irradiation device 5 of this embodiment is different from the first embodiment in the side wall 502a on the tip side of the main body 50 and the reflecting part 51. The configurations of the side wall 502b on the light source side and the first light exit 50b of this embodiment are the same as the configurations of the side wall 402b on the light source side and the first light exit 40b of the first embodiment, respectively.

[0046] The side wall portion 502a on the tip side has a shape of a part of the surface of a spheroid. Specifically, the side wall portion 502a on the tip side has a shape of the surface of a semi-ellipsoid and is convex. Here, the semi-ellipsoid has a major axis on the central axis X1 and a radius in the minor axis direction equal to the radius R of the cylindrical portion 501.

[0047] The reflecting portion 51 has a different portion provided on the inner circumferential surface of the side wall portion 502a on the tip side due to the different shape of the side wall portion 502a on the tip side. In other words, the shape of the portion of the reflecting portion 51 provided on the inner circumferential surface of the side wall portion 502a on the tip side is the surface shape of a semi-ellipsoid.

[0048] Even in the configuration of this embodiment, the illuminance of the light inside the main body 50 is highly uniform in the x-axis direction. Accordingly, the illuminance of the light emitted from the first emission port 50b is also highly uniform. Therefore, according to the light irradiation device 5 of this embodiment, it is possible to cauterize biological tissue with highly uniform light.

[0049] The shape of the side wall portion 502a on the tip side is not limited to this example. Instead of the surface shape of a semi-ellipsoid, it may be, for example, a semi-sphere, a side surface of a cone, or the like. The shape of the side wall portion 502b on the light source side is also not limited to this example. Instead of a flat plate shape, it may be, for example, a surface shape of a semi-ellipsoid, a semi-sphere, a side surface of a cone, or the like.

[0050] As described above, in the irradiation system 1 of the first embodiment, the light irradiation device 4 has a main body 40 having a cylindrical tubular portion 401 and a side wall portion 402 provided on at least one end face of the cylindrical portion 401, a first inlet 40a provided on the main body 40 for allowing external light to enter the inside of the main body 40, a long first outlet 40b provided on the main body 40 for emitting the light that has entered the inside of the main body 40 to the outside, and a reflector 41 provided on the inner circumferential surface of the main body 40. The same applies to the second embodiment.

[0051] According to this configuration, the illuminance distribution of the light inside the main body 40 becomes more uniform in the longitudinal direction of the main body 40. Therefore, the light is emitted to the outside from the entire area of ​​the first emission port 40b. This makes it possible to simultaneously irradiate the area having the spread of biological tissue with uniform light.

[0052] In the irradiation system 1 of the first embodiment, the first entrance 40a is provided in the side wall portion 402. The same applies to the second embodiment. With this configuration, it is possible to increase the proportion of light that travels at an angle close to the longitudinal direction of the main body portion 40. Furthermore, the variation in illuminance of light in the direction of the central axis X1 is reduced. Therefore, the number of reflections of light traveling inside the main body portion 40 can be reduced, and the loss of light associated with reflection can be reduced. This makes it possible to efficiently cauterize an area having an extension of biological tissue.

[0053] In the irradiation system 1 of the first embodiment, the side wall portion 402 may be provided on both end surfaces of the cylindrical portion 401. With such a configuration, it is possible to suppress the loss of light inside the main body portion 40. This makes it possible to more efficiently cauterize an area having an extension of biological tissue.

[0054] In the irradiation system 1 of the first embodiment, the shape of the first emission port 40b is such that the width in the longitudinal direction of the main body 40 is larger than the width in the direction perpendicular to the longitudinal direction of the main body 40. The same applies to the second embodiment. With this configuration, the uniformity of the illuminance of the light is further increased in the vicinity of the first emission port 40b. Therefore, the light is uniformly emitted to the outside from the entire area of ​​the first emission port 40b. This makes it possible to simultaneously irradiate the light with high uniformity to an area having an extension of biological tissue.

[0055] In the irradiation system of the first embodiment, the tubular portion 401 has a cylindrical shape. The same applies to the second embodiment. With this configuration, the illuminance distribution of light inside the main body portion 40 has high axial symmetry with respect to the central axis X1 of the main body portion 40 and high uniformity in the direction of the central axis X1. Therefore, the illuminance of light tends to be uniform over the inner circumferential surface of the tubular portion 401. This makes it possible to emit light with high uniformity regardless of the shape and arrangement of the first emission port 40b.

[0056] In the irradiation system of the first embodiment, the side wall 402 has a flat plate shape. With this configuration, it is possible to suppress localization of light in the vicinity of the side wall 402. This improves the uniformity of the illuminance of light in the direction of the central axis X1. Therefore, it is possible to irradiate light with even higher uniformity to an area having an extension of biological tissue.

[0057] In the irradiation system of the second embodiment, the side wall 502 has a shape of a part of the surface of a spheroid. With this configuration, light is focused at the focal position of the side wall 502a on the tip side away from the end face 3a of the light guide 3. This improves the uniformity of the illuminance of the light in the direction of the central axis X1. Therefore, light with high uniformity can be emitted from the first emission port 40b. Furthermore, with this configuration, the light irradiation device 5 can be easily inserted from the tip side into a narrow space in a living tissue. This makes it easier to operate the irradiation system, improving convenience.

[0058] In the irradiation system of the first embodiment, the cylindrical portion 401 may be configured in a polygonal shape. The same applies to the second embodiment. Even with such a configuration, the illuminance distribution of light inside the main body portion 40 has high uniformity in the direction of the central axis X1. This makes it possible to emit light with high uniformity regardless of the shape and arrangement of the first emission port 40b.

[0059] The above-mentioned embodiment is for the purpose of facilitating understanding of the present invention, and is not intended to limit the present invention. Furthermore, the present invention can be modified or improved without departing from the spirit of the present invention, and it goes without saying that the present invention includes equivalents thereof. EXAMPLES

[0060] The illuminance distribution of the light inside the main body and at the first light exit port was evaluated by a numerical simulation. The software used for the numerical simulation in this embodiment is a lighting simulator made by Best Media Co., Ltd. The details will be described below.

[0061] [Common conditions] In all of Examples 1 and 2 and Comparative Examples 1 to 3, the configuration of the main body is similar to that of the main body 40 of the first embodiment (FIGS. 2 to 4).

[0062] The length L of the cylindrical portion and the radius R of the bottom surface were 50 mm and 5 mm, respectively. The first exit port was rectangular, for example, as shown in FIG. 4. The lengths of the long sides and short sides of the rectangle were 30 mm and 1 mm, respectively. The diameter of the first entrance port was 5 mm. The light entering from the first entrance port was a 1 W light source.

[0063] [Individual conditions] Fig. 6 is a diagram for explaining individual conditions of this embodiment. Each of Examples 1 and 2 and Comparative Examples 1 to 3 has a different combination of reflectance of a portion of the reflector provided on the inner circumferential surface of the cylindrical portion (hereinafter referred to as "reflectance (cylindrical portion)") and reflectance of a portion of the reflector provided on the side wall portion (hereinafter referred to as "reflectance (side wall portion)"). Fig. 6 shows the reflectance (cylindrical portion) and reflectance (side wall portion) in Examples 1 and 2 and Comparative Examples 1 to 3.

[0064] [Evaluation criteria] Under the above-described conditions, if the reflectance of the cylindrical portion and the side wall portion is 98% or more, the illuminance at any position of the first exit port is 70,000 μW / mm 2 The above results indicated good cauterization.

[0065] The configuration of the main body part is appropriately designed according to the application of the irradiation system, although the ablation characteristics vary depending on the absorption coefficient and scattering coefficient of the type and part of the biological tissue to be ablated. The evaluation conditions are appropriately set according to the configuration of the main body part. Therefore, the above-mentioned evaluation conditions are specific to the configuration of the main body part of this embodiment.

[0066] [Calculation result] 7 shows the calculation results of the illuminance distribution of light inside (central axis X1) of the main body of Examples 1 and 2 and Comparative Examples 1 to 3. In this figure, the horizontal axis represents the distance from the center O on the central axis X1. The vertical axis represents the irradiance on the central axis X1.

[0067] 8 shows the calculation results of the illuminance distribution at the first exit port in Examples 1 and 2 and Comparative Examples 1 to 3. In this figure, the horizontal axis represents the distance from the center O of the first exit port in the longitudinal direction of the main body, and the vertical axis represents the irradiance at the first exit port.

[0068] From the results shown in Figure 8, it was found that increasing the reflectance of only the side wall portion does not increase the irradiance at the first emission port. However, the irradiance at the first emission port, which has a poor reflectance of the side wall portion, also deteriorates. Therefore, it was evaluated that the reflectance of the side wall portion is also important.

[0069] Here, Example 2 is a condition where only the reflectance (side wall portion) is reduced by 18% compared to Example 1. On the other hand, Comparative Example 1 is a condition where only the reflectance (cylindrical portion) is reduced by 18% compared to Example 1.

[0070] From the results of Examples 1 and 2 and Comparative Example 1, it can be seen that in the case of the configuration of the main body used in this example, the deterioration of the illuminance at the first exit due to the decrease in reflectance (cylindrical part) is greater than the deterioration of the illuminance at the first exit due to the decrease in reflectance (side wall part). This is also true for the deterioration of the illuminance on the central axis X1 (FIG. 7).

[0071] From this result, it can be seen that under the conditions of the main body used in this embodiment, the contribution of the reflectance (cylindrical portion) is greater than that of the reflectance (side wall portion). This is because the height L of the cylindrical portion is sufficiently larger than the radius R of the cylindrical portion. In this case, the area of ​​the reflecting portion provided on the inner peripheral surface of the cylindrical portion is sufficiently larger than the area of ​​the reflecting portion provided on the surface of the side wall portion.

[0072] Therefore, the frequency of reflection at the reflector provided on the inner circumferential surface of the cylindrical portion is higher than the frequency of reflection at the reflector provided on the surface of the sidewall portion, and thus the light loss at the reflector provided on the inner circumferential surface of the cylindrical portion is greater than the light loss at the reflector provided on the surface of the sidewall portion.

[0073] Therefore, under the conditions of the main body used in this embodiment, it is required that the reflectance (cylindrical portion) be higher than the reflectance (side wall portion). [Explanation of symbols]

[0074] 1: Irradiation system 2: Light source device 3: Light guide 4:Light irradiation device 40: Main body 401: Cylindrical part 402: Side wall 41:Reflector 40a: First entrance 40b: First exit port 5:Light irradiation device 50: Main body 51:Reflector 50a: First entrance 50b: First exit port

Claims

1. A main body having a tubular portion with openings on both end faces as viewed in the direction of its central axis, and first and second side wall portions provided on each of the openings; a first light entrance provided in the main body portion and allowing external light to enter the inside of the main body portion; a first light exit port provided in the main body portion and configured to emit light having entered the main body portion to the outside; A reflecting portion provided on an inner circumferential surface of the main body portion; A light irradiation device having the above structure.

2. The first entrance is provided in the second sidewall portion. The light irradiation device according to claim 1 .

3. The first light exit port has a shape in which its width in the longitudinal direction of the main body portion is larger than its width in a direction perpendicular to the longitudinal direction of the main body portion. The light irradiation device according to claim 1 or 2.

4. The tubular portion has a cylindrical shape. The light irradiation device according to any one of claims 1 to 3.

5. The first side wall portion has a shape of a flat plate. The light irradiation device according to any one of claims 1 to 4.

6. The first side wall portion has a major axis on the central axis of the cylindrical portion and has a surface shape of a semi-ellipsoid with a radius in a minor axis direction equal to the radius of the cylindrical portion. The light irradiation device according to any one of claims 1 to 4.

7. The cylindrical portion has a polygonal cross-sectional shape when cut along a plane perpendicular to the central axis. The light irradiation device according to any one of claims 1 to 3.

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