Method for manufacturing a light irradiation device

Abstract

To provide a method for manufacturing a light irradiation device capable of uniformly cauterizing a predetermined range of a biological tissue.SOLUTION: The method for manufacturing a light irradiation device with a casing, which is used to cauterize a biological tissue comprises: a generation process of generating a light reflection surface on one face of a member formed in a planar shape; and an assembling process of assembling the casing formed in a hollow and tubular shape by bending the member with the one face positioned inside. A process of forming a groove in the one face is further included and the member is bent along the groove.SELECTED DRAWING: Figure 3

Description

Technical Field

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[0001] The present invention relates to a method for manufacturing a light irradiation device.

Background Art

[0002] Devices for cauterizing biological tissue by light irradiation are known. For example, the device described in Patent Document 1 can cauterize biological tissue with light incident on one end of a rod-shaped light guide and emitted from the other end.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

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

[0005] Specifically, in order to fabricate a reflective surface on the inner surface formed hollow, various methods such as sputtering, vapor deposition, and coating are used for the inner surface, but in any case, it is necessary to expose the inner surface to perform the process. At this time, due to the shape and angle of the inner surface, unevenness occurs in the reflectance after the formation of the reflective surface by the above method, and a uniform amount of light cannot be obtained.

[0006] An object of the present invention is to provide a light irradiation device capable of uniformly cauterizing a predetermined range of biological tissue.

Means for Solving the Problems

[0007] To achieve the above objective, the present invention provides, in one aspect, a method for manufacturing a light irradiation device having a housing used for cauterizing biological tissue, comprising: a generation step of generating a light reflective surface on one surface of a flat plate-shaped member; and an assembly step of assembling a housing formed in a hollow cylindrical shape by bending the member with the one surface facing inward. [Effects of the Invention]

[0008] According to the present invention, a predetermined area of ​​biological tissue can be uniformly cauterized. [Brief explanation of the drawing]

[0009] [Figure 1] This is a diagram illustrating the overall configuration of the irradiation system according to the first embodiment. [Figure 2] This is a cross-sectional view of the light guide and light irradiation device of the irradiation system according to the first embodiment. [Figure 3] These are perspective views of the cylindrical part in the first embodiment, showing (a) before assembly and (b) after assembly. [Figure 4] This diagram shows side views of the light irradiation device in the first embodiment, arranged in order of the manufacturing process, and shows (a) the cylindrical part after assembly, (b) the state with the rear end member attached, and (c) the state after the pipe is attached. [Figure 5] This diagram shows side views of the light irradiation device in the first embodiment, arranged in order of the manufacturing process, with (a) showing the rear end member attached and (b) showing the screw and cap attached. [Figure 6] (a) A cross-sectional view of the light irradiation device using line VIa in Figure 5, and (b) A cross-sectional view of the light irradiation device using line VIb in Figure 5. [Figure 7] This is a flowchart of the manufacturing process for the light irradiation device in the first embodiment. [Figure 8] This is a plan view of a flat plate, modified in a different way. [Figure 9] This diagram shows perspective views of the light irradiation device according to manufacturing method 1 of the second embodiment, arranged in order of the manufacturing process, and shows (a) the cylindrical part before assembly, (b) the cylindrical part during assembly, and (c) the light irradiation device after manufacturing. [Figure 10] This is a flowchart of the manufacturing process for the light irradiation device in the second embodiment. [Figure 11] This diagram shows perspective views of the light irradiation device according to manufacturing method 2 of the second embodiment, arranged in order of the manufacturing process, and shows (a) the cylindrical part before assembly, (b) the cylindrical part during assembly, and (c) the light irradiation device after manufacturing. [Modes for carrying out the invention]

[0010] <First Embodiment> ==Irradiation System== Figure 1 is a diagram illustrating the configuration of the irradiation system 1 of this embodiment. The irradiation system 1 comprises a light source device 2, a light guide 3, and a light irradiation device 4.

[0011] [Light source device] Light source device 2 is a device that generates light for cauterizing biological tissue. Light source device 2 has a light source that generates light in a wavelength range matched to 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, etc., or light guided by the said light source via a transmission means such as an optical fiber.

[0012] [Light guide] Figures 2-6 are cross-sectional views illustrating the configuration of the light guide 3 and light irradiation device 4 of this embodiment. In the following description, as shown in Figure 2 and others, a Cartesian coordinate system consisting of mutually orthogonal x, y, and z axes will be used. Figure 2 is a cross-sectional view of the light guide 3 and light irradiation device 4 when cut by the xy plane passing through the center O of the main body 40, which will be described later.

[0013] The light guide 3 is a component, 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 (Figure 1). The other end of the light guide 3 is connected to the end of the light irradiation device 4 (Figures 1 and 2). Light entering one end of the light guide 3 from the light source device 2 propagates through the light guide 3 and enters the interior of the light irradiation device 4.

[0014] In the following description, unless otherwise specified, the end of the light guide 3 on the side of the light irradiation device 4 is simply referred to as the "end". Also, unless otherwise specified, the surface from which the light from the light source device 2 exits at the end of the light guide 3 is referred to as the "end face 3a". The end face 3a of the light guide 3 has a flat shape. In the light irradiation device 4, the end connected to the light guide 3 may be referred to as the rear end, and the opposite may be referred to as the front end.

[0015] [Light Irradiation Device] The light irradiation device 4 is a device that condenses the light from the light guide 3 and emits light to the biological tissue to be ablated. The light irradiation device 4 includes a main body 40, a cap 41 fixed to the main body 40, a rear end member 42, and a pipe 43 covering the outer periphery of the main body 40.

[0016] (Main Body) The main body 40 is a hollow cylindrical member and has a cylindrical portion 401 and a front wall portion 402. The cylindrical portion 401 and the front wall portion 402 form the housing of the main body 40. The main body 40 has a polygonal hollow cross-section (FIG. 6). Hereinafter, as an example, the case where the main body 40 has a substantially regular hexagonal hollow cross-section will be described.

[0017] The cylindrical portion 401 is formed in a cylindrical shape with a regular hexagonal cross-section centered on the axis X1. Inside the cylindrical portion 401, a reflective surface 401a capable of reflecting light, on which a material for reflecting light is formed, is formed. As the material formed for forming the reflective surface 401a, metal materials such as silver (Ag) and aluminum (Al) are used. When the light generated by the light source device 2 is in the wavelength range of infrared light, metal materials such as gold (Au) are used as the material for reflecting light. Various methods such as sputtering, vapor deposition, and coating can be adopted as the film-forming method.

[0018] The axis X1 is parallel to the X axis. In the following description, the lengths of the main body 40 and the cylindrical portion 401 along the axis X1 are referred to as the "length of the main body 40" and the "length of the cylindrical portion 401", respectively. Also, the midpoint in the length direction of the cylindrical portion 401 on the axis X1 is referred to as the "center O of the cylindrical portion 401" or the "center O of the main body 40". Also, the length of the cylindrical portion 401 is denoted as L1.

[0019] The cylindrical portion 401 and the pipe 43 have elongated outlets 4b that extend parallel to the axis X1. The outlets 4b are holes that extend radially through the light reflecting device 4, penetrating both the cylindrical portion 401 and the pipe 43, and connecting the internal and external spaces of the light reflecting device 4. The shape of the outlets 4b is a rectangle with a long side parallel to the axis X1 (Figures 2 and 3). The outlets 4b have the function of emitting light emitted from the end face 3a of the light guide 3 to the outside. By positioning the outlets 4b at the site of ablation of biological tissue and emitting light from the outlets 4b, the biological tissue can be ablated.

[0020] The shape of the injection port 4b may be elliptical, a rounded rectangle, or the like. There may also be multiple injection ports 4b. Furthermore, the interior of the main body 40 may be sealed by filling the injection ports 4b with a transparent material. Alternatively, the interior of the main body 40 may be sealed by covering the injection ports 4b with a transparent material from either the outer or inner circumferential surface of the main body 40.

[0021] The front wall portion 402 is a roughly hexagonal flat plate member. The front wall portion 402 is fixed to the front end of the cylindrical portion 401 so as to be perpendicular to the axis X1. The front wall portion 402 faces inward into the cylindrical portion 401 and has a reflective surface 402a perpendicular to the axis X1. The reflective surface 402a has a light-reflecting material deposited on it and has the function of reflecting light. The material and method used for deposition are the same as for the reflective surface 401a.

[0022] The cap 41 is a component attached to the front end of the main body 40 so as to cover the front wall 402, and is formed in a substantially hemispherical shape (Figures 5(b) and 6(a)).

[0023] The rear end member 42 is a member fixed to the rear end of the cylindrical portion 401. The rear end member 42 is a member formed in a substantially circular shape when viewed in the X1 axial direction and has a hole 42a extending in the X1 axial direction. The rear end member 42 is fixed to the cylindrical portion 401 by a screw 42B. In detail, the screw 42B is connected to the rear end member 42 by screw action, and its end contacts the outer circumferential surface of the cylindrical portion 401.

[0024] The hole 42a is formed in a substantially hexagonal shape when viewed in the X1 axis direction. The cylindrical portion 401 is inserted into the hole 42a. Furthermore, the end of the light guide 3 is inserted into the hole 42a and fixed so that its end face 3a faces the inside of the cylindrical portion 401. This allows light from the light source device 2 to be emitted from the end face 3a of the light guide 3 and incident into the inside of the main body portion 40.

[0025] The pipe 43 is a cylindrical member extending in the X1 axis direction. The pipe 43 has a hole 43a that extends in the X1 axis direction and is approximately hexagonal in shape when viewed in the X1 axis direction, into which the cylindrical portion 401 is inserted (Figures 2 and 6(b)). The diameter of the hole 43a is slightly smaller than the outer diameter of the cylindrical portion 401. Therefore, the pipe 43 can press the inserted cylindrical portion 401 radially inward and maintain the shape of the cylindrical portion 401. As described above, the pipe 43 has an outlet 4b.

[0026] 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 into the main body 40 via the light guide 3, but it is not limited to this. For example, a light source element such as an LED element may be placed inside the main body 40. Furthermore, the light guide 3 may be further provided with a gripping portion at a predetermined distance from the light irradiation device 4 for the operator to grasp by hand when operating the irradiation system 1.

[0027] ==Assembly== The method for manufacturing the light irradiation device 4 is described below. As shown in Figure 7, the manufacturing of the light irradiation device 4 includes steps S1 to S6.

[0028] First, in step S1, a flat plate PL1 and a front wall portion 402 are prepared (Figure 3). The flat plate PL1 is the original component for the cylindrical portion 401, and is a roughly rectangular flat plate with a short side and a long side of length L1. As shown in Figure 3(a), an opening corresponding to the injection port 4b may be formed in the flat plate PL1 beforehand, or it may be formed in step S2, which will be described later.

[0029] In step S2, five grooves G are formed in the flat plate PL1, parallel to the long side. The grooves G are formed at equal intervals. As shown in Figure 3(a), the cross-section of the grooves G is formed in a wedge shape, but it may be formed in other shapes as well.

[0030] The number of grooves G depends on the cross-sectional shape of the main body 40. For example, if the main body 40 has an octagonal cross-section, seven grooves G will be formed.

[0031] In the next step S3, a light-reflecting material is deposited on the surfaces of the flat plate PL1 and the front wall portion 402. More specifically, the surface of the flat plate PL1 is first polished, and then a reflective material such as a metal is deposited on the surfaces of the flat plate PL1 and the front wall portion 402. As mentioned above, methods for deposition include sputtering, vapor deposition, and coating. Through this process, reflective surfaces 401a and 402a are formed.

[0032] Next, the main body 40 is assembled (S4). First, the flat plate PL1 is bent along the groove G, and the two long sides are brought together without any gaps (Figure 3(b)). This assembles a cylindrical part 401 with a roughly regular hexagonal cross-section. The front wall part 402 is attached to the front end of the cylindrical part 401 such that the reflective surface 402a faces the cylindrical part 401 (Figures 3(b) and 4(a)).

[0033] In step S5, the rear end of the main body 401 is inserted into the rear end member 42. Also, a pipe 43 is attached to the cylindrical part 401. Specifically, the cylindrical part 401 is inserted into the inside of the pipe 43. Here, the diameter of the hole 43a of the pipe 43 is smaller than the outer diameter of the cylindrical part 401. Therefore, the pipe 43 applies force to the cylindrical part 401 by pressing it from the outside. Because the cylindrical part 401 is pressed by the pipe 43, it is prevented that the joint (the joint of the long side of the flat plate PL1) will not separate or that the cross-section will not deform.

[0034] In step S6, the cap 41 is fixed to the front end of the main body 40 so as to cover the front wall 402 (Figure 5). The rear end member 42 is fixed by a screw 42B.

[0035] The light irradiation device 4 is completed by following the above procedure. After completion, the light guide 3 is inserted into the rear end member 42, and the light irradiation device 4 and the light guide 3 are connected.

[0036] In the above manufacturing method, the reflective surfaces 401a and 402a are formed before the assembly of the cylindrical portion 401. This makes it possible to obtain reflective surfaces 401a and 402a in which the light-reflecting material is uniformly deposited, i.e., with uniform light-reflecting performance.

[0037] ==About the propagation of light== Light generated by the light source device 2 propagates through the light guide 3 and exits from the end face 3a of the light guide 3 (i.e., enters the interior of the main body 40 of the light irradiation device 4). At this time, light traveling at various angles relative to the end face 3a of the light guide 3 enters the interior of the main body 40.

[0038] A portion of the light emitted from the end face 3a of the light guide 3 propagates toward the reflective surface 402a, repeatedly reflecting off the reflective surface 401a. The light that reaches the reflective surface 402a on the tip side is reflected by the reflective surface 402a.

[0039] In other words, the light inside the main body 40 propagates by repeatedly reflecting off the reflective surfaces 401a and 402a, unless it is emitted outside the main body 40.

[0040] A portion of the light traveling through the main body 40 reaches the output port 4b and is emitted from the output port 4b to the outside of the main body 40. The light emitted from the output port 4b can be used to cauterize living tissue.

[0041] As described above, the reflective material is uniformly deposited on the reflective surfaces 401a and 402a. Therefore, the illuminance distribution of light is uniform inside the main body 40.

[0042] Furthermore, the cylindrical portion 401 has a polygonal shape that is symmetrical with respect to axis X1. Therefore, in the illuminance distribution of light inside the main body portion 40, the uniformity in the longitudinal direction of the main body portion 40 is higher than the uniformity in other directions.

[0043] In this embodiment, the output port 4b has an elongated shape with a length in the longitudinal direction of the main body 40. The illuminance of light inside the main body 40 is highly uniform. Consequently, the illuminance of the light emitted from the output port 4b is also highly uniform. Therefore, with the light irradiation device 4 of this embodiment, biological tissue can be cauterized with highly uniform light.

[0044] Furthermore, the larger the length L1 of the cylindrical portion 401, the higher the frequency of reflection from the reflective surface 401a provided on the inner circumferential surface of the cylindrical portion 401 within the main body portion 40. Therefore, the larger the length L1 of the cylindrical portion 401, the higher the reflectivity of at least the reflective surface 401a provided on the inner circumferential surface of the cylindrical portion 401 is necessary to suppress light loss within the main body portion 40. Incidentally, if the reflective surface 401a is formed by depositing Ag (silver), a reflectivity of about 96-98% can be obtained.

[0045] The front wall portion 402 may be molded integrally with the cylindrical portion 401. In this case, the main body portion 40 can be assembled by preparing a flat plate PL1 with the front wall portion 402 joined, as shown in Figure 8, and bending it along the groove G. In this case, it is desirable to also form the groove G between the cylindrical portion 401 (flat plate PL1) and the front wall portion 402 in step S2.

[0046] Furthermore, a reflective surface perpendicular to the axis ■1 is provided not only at the front end of the cylindrical portion 401, but also at the rear end. Light may be reflected. Alternatively, the front wall portion 402 may be omitted, and the configuration may be such that light is emitted from the front end of the main body portion 40.

[0047] Furthermore, in this embodiment, the cross-sectional shape of the main body 40 when cut by a plane perpendicular to the axis X1 (yz plane) (hereinafter simply referred to as "cross-sectional shape of the main body 40") is approximately a regular hexagon, but it is not limited to this. The cross-sectional shape of the main body 40 may be a polygon. For example, if the cross-sectional shape is a square, the cylindrical part 401 will be a cylinder with a square cross-section.

[0048] <Second Embodiment> Figure 9 is a diagram illustrating the configuration of the light irradiation device 5 according to the second embodiment. The light irradiation device 5 is a component connected to the light guide 3, similar to the first embodiment.

[0049] The main body 50 of the light irradiation device 5 includes a cylindrical portion 501 with a roughly circular cross-section and axis X1 as its center. The main body 50 is fixed to the front end of the cylindrical portion 501, and is roughly circular in shape when viewed in the axial direction. It has a circular front wall portion 502. Similar to the first embodiment, a cap 51 is attached to the front of the main body portion 50 and a rear end member 52 is attached to the rear. A substantially cylindrical pipe 53 is attached to the main body portion 50 so as to cover the outer circumference of the main body portion 50.

[0050] (Production method 1) The light irradiation device 5 is manufactured according to the process shown in Figure 10. Unlike the first embodiment (Figure 7), the process in Figure 10 omits the step S2 for forming the groove G. All other steps are the same as in the first embodiment.

[0051] In the manufacturing process, a flat plate PL2 is prepared (S11), and after polishing the surface of the flat plate PL2, reflective surfaces 501a and 502a are formed on the surface of the flat plate PL2 using a light-reflecting material (S13, Figure 9(a)). The polishing method, the method of forming the inner surface, and the materials used are the same as in step S3 of the first embodiment. In Figure 9(a), an injection port 5b is formed on the flat plate PL2, but the injection port 5b may be formed in a later step.

[0052] Furthermore, in step S14, the flat plate PL2 is bent in the direction of its short side, and the long sides are brought together without any gaps to form a cylindrical portion 501 (Figure 9(b)). The front wall portion 502 is attached to the front end of the cylindrical portion 501.

[0053] Next, a substantially cylindrical pipe 53 is attached so as to cover the outer circumference of the cylindrical portion 501 (S15, Figure 9(c)). Similar to the first embodiment, the inner diameter of the pipe 53 is smaller than the outer diameter of the cylindrical portion 501. The attachment of the pipe 53 presses the cylindrical portion 501 from the outside, maintaining its shape. In addition, the rear end member 52 is attached to the rear end of the main body portion 50.

[0054] Furthermore, the light irradiation device 5 is completed when the cap 51 is attached to the front end of the main body 50 (S16).

[0055] (Production method 2) Furthermore, the main body 50 can also be assembled using the following methods and materials.

[0056] First, as shown in Figure 11(a), a flat plate PL3 is prepared that is longer and narrower than the flat plate PL2, its surface is polished, and a reflective surface 501a is formed (steps S11, S13).

[0057] Next, the flat plate PL2 is bent spirally around the X1 axis to assemble the cylindrical portion 501 (step S14, Figure 11(b)). In addition to the cap 51, the rear end member 52 and the pipe 53 are attached to the cylindrical portion 501, thereby maintaining the shape of the main body portion 50 (step S15, Figure 11(c)).

[0058] Furthermore, the cross-sectional shape of the cylindrical portion 501, the front wall portion 502, and the pipe 53 are not limited to a perfect circle. These shapes can be formed into an oval shape. Here, "oval shape" is a concept that encompasses perfect circles, ellipses, oblongs, and egg shapes, and is a figure formed by a smooth, continuous curve that is convex outward, and is characterized by being symmetrical with respect to at least one axis.

[0059] The shape of the front wall portion 502 at the tip is not limited to this example. For example, it may be a hemisphere, the side of a cone, or other shapes.

[0060] <Effects> The method for manufacturing the light irradiation devices 4 and 5 according to the above embodiment comprises steps S3 and S13 of generating reflective surfaces 401a and 501a that reflect light on one surface of flat plates PL1, PL2, and PL3, and steps S4 and S14 of assembling hollow cylindrical parts 401 and 501 by bending a member with the reflective surfaces 401a and 501a on the inside.

[0061] With this configuration, reflective surfaces 401a and 501a are generated on the flat plates PL1, PL2, and PL3, making it possible to generate a uniform light reflection surface. As a result, the uniformity of light illumination inside the cylindrical section 401 is improved. This makes it possible to irradiate areas with a wide area of ​​biological tissue with uniform light.

[0062] In more detail, when forming a light-reflecting surface inside the main body 40 using conventional technology, it is impossible to uniformly distribute the metal deposition gas within a hollow cylindrical or polygonal prism shape. Therefore, it was necessary to cut the cylindrical or polygonal shape longitudinally into two or more parts, expose the inner surface, and apply the reflective film. However, this results in a three-dimensional cross-section and inner surface, such as a semicircular cross-section for a cylinder or a polygonal cross-section for a polygonal prism. When polishing or deposition is performed on such a three-dimensional structure, uneven polishing or deposition is likely to occur, making it difficult to create a uniform deposition surface.

[0063] On the other hand, the problems of the conventional technology described above are solved in each of the embodiments. In each embodiment, polishing and film deposition can be performed on a flat surface, making it possible to create a uniform light-reflecting surface.

[0064] The manufacturing method according to the above embodiment includes step S2 of forming a groove G on the surface of the flat plate PL1, and in steps S4 and S14, the flat plate PL1 is bent along the groove G.

[0065] By creating grooves G in this way and bending the flat plate PL1 along the grooves G to assemble the cylindrical portion 401, the assembly of the cylindrical portion 401 is performed accurately. Furthermore, it becomes possible to assemble a cylindrical portion 401 with high precision.

[0066] In steps S4 and S14 of the above embodiment, the cylindrical portion 401 is assembled to have a polygonal cross-section, and the cylindrical portion 501 is assembled to have a circular or oval cross-section. In particular, the cylindrical portion 501 can be assembled by bending the flat plate PL3 into a spiral shape.

[0067] With the above configuration, it is possible to form cylindrical bodies with various cross-sectional shapes depending on the application. Furthermore, the bending method can be selected according to the material of the flat plates PL1, PL2, and PL3. Since an inner surface with uniform reflective performance can be obtained regardless of the cross-sectional shape of the cylindrical parts 401 and 501, the performance of the light irradiation devices 4 and 5 can be improved.

[0068] In the above embodiment, pipes 43, 53, or rear end members 42 (all of which correspond to retaining members) are attached so as to cover the outer circumference of the cylindrical portions 401, 501 (S5, S15).

[0069] Because the shape of the cylindrical parts 401 and 501 is maintained using pipes 43 and 53 or the rear end member 42, there is no need to glue the joints of the cylindrical parts 401 and 501 during assembly (S4, S14). The shape of the cylindrical parts 401 and 501 can be accurately maintained by the simple method using pipes 43 and 53, resulting in high-performance light irradiation devices 4 and 5.

[0070] In the above embodiment, steps S3 and S13 for generating the inner surface include polishing one surface of the flat plates PL1, PL2, and PL3, and depositing metal onto this surface to generate a reflective surface.

[0071] Since polishing and metal deposition are performed on a flat plate, it is possible to obtain reflective surfaces 401a and 501a with uniform reflective performance. This allows for the creation of high-performance light irradiation devices 4 and 5. [Explanation of Symbols]

[0072] 1: Irradiation System 2: Light source device 3: Light guide 4:Light irradiation device 40: Main body 401: Cylindrical part 402: Front wall 4b: Output port 5:Light irradiation device 50: Main body

Claims

1. A method for manufacturing a light irradiation device having a housing used for cauterizing biological tissue, comprising: a generating step of generating a light reflecting surface on one surface of a member formed in a flat plate shape; and assembling the housing formed into a hollow cylindrical shape by bending the member with the one surface facing inward.

2. further comprising forming a groove in the one surface; The method for manufacturing a light irradiation device according to claim 1 , wherein the member is bent along the groove in the assembling step.

3. 3. The method for manufacturing a light irradiation device according to claim 1, wherein in the assembly step, the housing is assembled to have a polygonal cross section.

4. 3. The method for manufacturing a light irradiation device according to claim 1, wherein in the assembly step, the housing is assembled to have a circular or oval cross section.

5. The method for producing a light irradiation device according to claim 4 , wherein the member is bent into a spiral shape in the assembling step.

6. After the assembly process, The manufacturing method according to claim 1 , further comprising the step of attaching a holding member covering the outer periphery of the housing to the housing.

7. The generating step includes: polishing the one surface; The method for manufacturing a light irradiation device according to claim 1 , further comprising the step of: depositing metal on said one surface to form said reflecting surface.

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