Ultraviolet therapy device

Abstract

The present invention provides an ultraviolet therapy device equipped with a heat sink with a structure that can reduce temperature variations between multiple LED light sources that rise due to ultraviolet emission. [Solution] The ultraviolet therapy device comprises an LED substrate on which an LED light source that emits light including ultraviolet light is mounted, and a heat sink. The heat sink has a heat sink base attached to the side of the LED substrate opposite to the side on which the LED light source is mounted, and a plurality of fin portions provided on the side of the heat sink base opposite to the LED substrate side. The plurality of fin portions has a first group, which is a group of some of the plurality of fin portions provided in the central part of the heat sink base, and a second group, which is a group of the remaining plurality of fin portions provided in the peripheral part of the heat sink base, which is the outer part of the first group. The heat dissipation capacity of the first group is higher than that of the second group.

Description

Technical Field

[0001] The present invention relates to an ultraviolet therapy device.

Background Art

[0002] Conventionally, as light therapy, there is ultraviolet therapy using ultraviolet rays in wavelength ranges such as UVA (wavelength 320 nm to 400 nm) and UVB (wavelength 280 to 320 nm). In ultraviolet therapy, immunosuppression is achieved by ultraviolet irradiation to obtain a therapeutic effect. For example, Patent Document 1 discloses an ultraviolet therapy device including a plurality of LED light sources that emit ultraviolet rays and a heat sink that dissipates heat so that the plurality of LED light sources do not rise above a predetermined temperature.

[0003] As shown in FIG. 8, the ultraviolet therapy device of Patent Document 1 includes a plurality of LED light sources 125a and a heat sink 129. Further, although not shown in the figure, the ultraviolet therapy device of Patent Document 1 includes a fan for cooling the heat sink 129. The heat sink 129 includes a base portion 129a and a plurality of fin portions 129b that stand upright from the base portion 129a. The base portion 129a and the fin portions 129b are made of a member having a high thermal conductivity such as aluminum.

[0004] Also, as shown by the dashed circles in FIG. 8, the plurality of LED light sources 125a are arranged in a two-dimensional array on a substrate (not shown). The heat sink 129 is attached to the surface of the LED substrate on the side opposite to the mounting surface on which the plurality of LED light sources 125a are mounted. The plurality of fin portions 129b each protrude in a direction opposite to the mounting surface side of the LED substrate and are arranged in a two-dimensional array on the base portion 129a.

Prior Art Documents

Patent Documents

[0005]

Patent Document 1

Summary of the Invention

[0006] As shown in Figure 8, some of the multiple LED light sources 125a arranged in a two-dimensional array are surrounded on eight sides by other LED light sources 125a, such as the LED light source 125a enclosed by the dashed rectangle (hereinafter referred to as the "central LED light source 125a"). In addition, some LED light sources 125a located outside the dashed rectangle (hereinafter referred to as the "peripheral LED light sources 125a") have LED light sources 125a in three to five directions around them, but no other LED light sources 125a in any of the eight directions. On the other hand, as shown in Figure 9(a), let X1 be the coordinate of the +X side edge of the substrate 125b, X0 be the coordinate of the center in the X direction, and X2 be the coordinate of the -X side edge. Here, the lower graph in Figure 9(a) shows the relationship between the position in the X direction of the LED light source 125a and the temperature.

[0007] The LED light source 125a is composed of UV-LEDs, and its temperature rises as the operating time increases. The conventional heat sink 129 is provided to dissipate this heat rise. In a configuration using this conventional heat sink 129, focusing on the LED light sources 125a enclosed by the dashed line in Figure 9(a), the measured temperatures of these LED light sources are shown in the temperature distribution in the lower graph of Figure 9(a). In this graph, the horizontal axis is position X, and the vertical axis is temperature (°C). That is, the LED light sources 125a in the center are hotter than those at the edges. Specifically, the LED light source 125a at the center X0 is the hottest, and the temperature decreases as you move from X0 towards X1 or X2, with the lowest temperature at X1 and X2.

[0008] This is because the central LED light source 125a has more surrounding LED light sources 125a than the peripheral LED light sources 125a. In particular, the central LED light source 125a is surrounded by other LED light sources 125a in all eight directions. Due to these central LED light sources 125a, which tend to get hot, a high-temperature area is generated in the central part, as shown by the shaded circle in Figure 9(a). Here, Figure 9(b) is a graph showing the relationship between wavelength and illuminance of the LED light source 125a. In this graph, the horizontal axis is wavelength (nm) and the vertical axis is illuminance (mW / cm²). 2 )

[0009] As shown in Figure 9(b), the wavelength and illuminance of the emitted light from the LED light source 125a fluctuate with temperature changes. Therefore, when irradiating the skin with light in the wavelength range used in ultraviolet therapy, the likelihood of developing erythema, a side effect, differs depending on the temperature. Specifically, the wavelength of the LED light source 125a shifts to longer wavelengths as the temperature increases.

[0010] For example, the wavelength of ultraviolet light emitted by the 308nm LED light source 125a shifts 1nm toward longer wavelengths when the temperature rises by 40°C. Furthermore, a 2nm shift toward longer wavelengths in ultraviolet light causes a 40-50% change in the minimum erythema dose (MED), which is the lowest amount of ultraviolet radiation required to cause erythema in the skin. Generally, when used at room temperature (25°C), the temperature of the LED light source 125a rises to 70-75°C.

[0011] For example, the MED for light with a wavelength of 308 nm is 200 mJ / cm². 2 To achieve the maximum therapeutic effect without causing side effects (erythema), the irradiation dose of an ultraviolet therapy device using a 308nm wavelength LED light source should be set to, for example, 190mJ / cm². 2Let's consider the case where treatment is received with the irradiation dose set to (slightly lower than MED). In this case, the 308nm LED light source of the UV treatment device actually becomes an LED light source with a peak at 309nm wavelength due to the lengthening of the wavelength caused by the temperature rise, and the effect on the skin will be smaller than expected. Therefore, 190mJ / cm² 2 With this irradiation method, it's not possible to achieve the maximum therapeutic effect on the affected area; in other words, it would have been possible to irradiate a little more within the area where erythema did not appear.

[0012] In other words, the longer the wavelength of ultraviolet light, the less likely erythema is to occur, but conversely, the therapeutic effect may decrease. Therefore, if there is a temperature variation between the central LED light source 125a and the peripheral LED light source 125a, the illuminance of the therapeutically effective wavelength will become uneven within the ultraviolet irradiation surface. As a result, the therapeutic effect within the irradiation surface will be uneven, and problems may arise where the erythematous reaction within the irradiation surface is not consistent. Therefore, the object of the present invention is to provide an ultraviolet therapy device equipped with a heat sink with a structure that can reduce temperature variations between multiple LED light sources that rise due to ultraviolet emission. [Means for solving the problem]

[0013] To solve the above problems, one embodiment of the ultraviolet therapy device according to the present invention comprises a housing having a light emission window that emits light including ultraviolet light, an LED substrate provided inside the housing facing the light emission window and on which a plurality of LED light sources that emit light including ultraviolet light toward the light emission window are mounted in a two-dimensional array, a heat sink attached to the LED substrate inside the housing for dissipating heat from the LED substrate, and a blower provided inside the housing on the side of the heat sink opposite to the LED substrate, wherein the heat sink is on the side of the LED substrate opposite to the mounting surface of the LED light sources The device has a heat sink base attached to the LED substrate, and a plurality of fin portions provided on the side of the heat sink base opposite to the LED substrate side, extending from that side in the direction opposite to the LED substrate side. The plurality of fin portions consists of a first group, which is a group of some of the plurality of fin portions provided in the central part of the heat sink base, and a second group, which is a group of the remaining plurality of fin portions provided in the peripheral part of the heat sink base, which is the outer part of the first group, and the heat dissipation capacity of the first group is higher than that of the second group. Furthermore, in the above-mentioned ultraviolet therapy device, the thermal conductivity of the first group may be greater than that of the second group. Furthermore, in the above-described ultraviolet therapy device, the first group may be made of copper, and the second group may be made of aluminum.

[0014] Furthermore, in the above-described ultraviolet therapy device, a portion of the heat sink base facing the first group may be made of a material having the same thermal conductivity as the first group, and the other portion of the heat sink base facing the second group may be made of a material having the same thermal conductivity as the second group.

[0015] Furthermore, in the ultraviolet therapy device described above, the heat sink may be configured such that a gap is formed between adjacent fin portions of the first group and the second group, which serves as a flow path for cooling air, and the total surface area per unit area of ​​the fin portions of the first group facing the central portion of the heat sink base is larger than the total surface area per unit area of ​​the fin portions of the second group facing the peripheral portion of the heat sink base.

[0016] Furthermore, in the ultraviolet therapy device described above, the heat sink has gaps formed between adjacent fin portions of the first group and the second group that serve as airflow channels for cooling air, and the multiple fin portions constituting the first group and the second group have at least the same width in the direction of arrangement, and the density of the fin portions per unit area of ​​the central portion of the first group facing the central portion of the heat sink base may be greater than the density of the fin portions per unit area of ​​the peripheral portion of the second group facing the peripheral portion of the heat sink base.

[0017] Furthermore, in the ultraviolet therapy device described above, the heat sink may be configured such that a gap is formed between adjacent fin portions of the first group and the second group, which serves as a flow path for cooling air, the thickness of each fin portion constituting the first group is smaller than the thickness of each fin portion constituting the second group, and the spacing between adjacent fin portions of the first group is smaller than the spacing between adjacent fin portions of the second group. Furthermore, in the ultraviolet treatment device described above, the total surface area of ​​the fin portions per unit area of ​​the opposing heat sink base may be continuously and gradually increasing from the ends of the heat sink base to the center.

[0018] Also, in the above-described ultraviolet ray treatment device, the width in the arrangement direction of each fin portion constituting the first group of the heat sink is smaller than the width in the arrangement direction of each fin portion constituting the second group, and the number of fin portions per unit area of the central portion of the first group facing the central portion of the heat sink base is larger than the number of fin portions per unit area of the peripheral portion of the second group facing the peripheral portion of the heat sink base.

[0019] Also, in the above-described ultraviolet ray treatment device, a first part including the first group of the heat sink and the central portion of the heat sink base, and a second part including the second group and the peripheral portion of the heat sink base may be configured as separate members, and the first part may be configured to be detachable from the second part.

Advantages of the Invention

[0020] The ultraviolet ray treatment device of the present invention can provide an ultraviolet ray treatment device provided with a heat sink having a structure capable of reducing the variation in the temperatures of a plurality of LED light sources that increase due to the emission of ultraviolet rays.

Brief Description of the Drawings

[0021] [Figure 1] It is a block diagram showing a schematic configuration of an ultraviolet ray treatment device 1 in a first embodiment. [Figure 2] It is a diagram showing a configuration example of a treatment tool. [Figure 3A] (a) is a diagram showing a schematic configuration of a first heat sink according to a first configuration example of the first embodiment, and (b) is a cross-sectional view taken along line A-A of (a). [Figure 3B] (a) is a diagram showing a schematic configuration of a second heat sink according to a second configuration example of the first embodiment, and (b) is a cross-sectional view taken along line B-B of (a). [Figure 4] (a) is a diagram showing a schematic configuration of a third heat sink according to a first configuration example of the second embodiment, and (b) is a diagram showing a schematic configuration of a fourth heat sink according to a second configuration example of the second embodiment. [Figure 5] (a) is a diagram showing the schematic configuration of the fifth heat sink according to the first configuration example of the third embodiment, and (b) is a diagram showing the schematic configuration of the sixth heat sink according to the second configuration example of the third embodiment. [Figure 6] (a) is a diagram showing the schematic configuration of the seventh heatsink according to the first configuration example of the fourth embodiment, and (b) is a diagram showing the schematic configuration of the eighth heatsink according to the second configuration example of the fourth embodiment. [Figure 7] This figure shows the schematic configuration of the ninth heatsink according to the fifth embodiment. [Figure 8] This diagram shows the arrangement of a conventional heatsink and LED light source. [Figure 9] (a) is a diagram showing the schematic configuration of the LED substrate at the top, and a graph at the bottom showing the relationship between the position of the LED light source on the LED substrate and the temperature. (b) is a graph showing the relationship between the wavelength of the LED light source and the illuminance. [Modes for carrying out the invention]

[0022] Various embodiments for carrying out the present invention will be described in detail below with reference to the attached drawings. The embodiments described below are merely examples of means for realizing the present invention, and should be modified or changed as appropriate depending on the configuration of the apparatus to which the present invention is applied and various conditions. The present invention is not limited to the embodiments described below.

[0023] Furthermore, in the following drawings, identical or similar parts are denoted by the same or similar reference numerals. However, it should be noted that the drawings are schematic, and the vertical and horizontal dimensions and scale of the members or parts may differ from the actual dimensions. Therefore, specific dimensions and scales should be determined by referring to the following explanation. Also, it goes without saying that there may be parts where the dimensional relationships and ratios differ between drawings. [First Embodiment] 〔composition〕 Hereinafter, a first embodiment of the present invention will be described with reference to the drawings. Figures 1, 2, 3A, and 3B show the first embodiment. Figure 1 is a block diagram showing the schematic configuration of the ultraviolet therapy device 1 according to the first embodiment.

[0024] The ultraviolet therapy device 1 comprises a therapy device 2 having an LED light source that emits light including ultraviolet light, and a main unit 3 that supplies power to the therapy device 2 and controls the LED light source. In the example shown in Figure 1, the therapy device 2 is configured to be portable with one hand (handheld type configuration) and can be freely displaced by the operator within the range of the connecting wire 37 to the main unit 3. Here, the operator is a person other than the patient (for example, a doctor, nurse, etc.). In the following explanation, ultraviolet light and light containing ultraviolet light may sometimes be simply referred to as "light." The treatment device 2 comprises a light irradiation unit 21 that houses an LED light source, a gripping unit (handle) 22 for the operator to hold with one hand, and a light emission window 23 provided in the light irradiation unit 21 that emits light.

[0025] The main unit 3 comprises an input unit 31, a recording unit 32, a display unit 33, a power supply unit 34, a control unit 35, and an LED drive unit 36. The treatment device 2 and the main unit 3 are connected by a connecting wire 37, which comprises a power supply wire 37a (shown by a thick line) and a signal wire 37b (shown by a thin line). The input unit 31 receives information entered by the operator and outputs that information to the control unit 35. The information entered by the operator includes information regarding the amount of ultraviolet light to be irradiated onto the affected area. The recording unit 32 is a non-volatile recording medium on which information related to the drive control of the LED light source and the display control of the display unit 33 is recorded.

[0026] The display unit 33 can display the ultraviolet emission intensity, irradiation time, and elapsed time during ultraviolet irradiation. In addition, the display unit 42 can display information (such as an error message) indicating that an abnormality has occurred in the ultraviolet therapy device 1 if any abnormality occurs. The power supply unit 34 converts the power supplied from the external power supply 8 into an appropriate voltage and supplies it to each of the subsequent units. The control unit 35 controls the LED drive unit 36 ​​based on the information input from the input unit 31 and the information recorded in the recording unit 32, thereby controlling the irradiation amount (emission illuminance or irradiation time) of the LED light source of the treatment device 2. The LED drive unit 36 ​​supplies power to the LED light source according to the control signal from the control unit 35. The following describes the procedure by which the operator irradiates the affected area with ultraviolet light using the ultraviolet treatment device 1 of this embodiment. First, the operator operates the input unit 31 to input information regarding the amount of ultraviolet light to be irradiated onto the affected area (irradiation time and emitted irradiance). Next, the operator holds the gripping part 22 of the treatment device 2 and brings the light emission window 23 into contact with or close to the affected area. Then, the operator presses a switch (not shown) located on the gripping part 22, for example. The LED light source of the treatment device 2 then lights up, and ultraviolet light irradiation to the affected area begins. Subsequently, once the UV irradiation reaches the input irradiation level (the set irradiation time is reached), the LED light source automatically turns off. Next, the configuration of the treatment device 2 will be described in detail based on Figure 2. Figure 2 is a diagram showing an example of the configuration of the treatment device 2.

[0027] As shown in Figure 2, the light irradiation unit 21 of the treatment device 2 comprises a housing 24 having a light emission window 23. The housing 24 has an opening, and the light emission window 23 is mounted in this opening. The shape of the housing 24 can be, for example, a rectangular parallelepiped. The shape of the light emission window 23 can be, for example, a rectangle of 50 mm x 50 mm. The housing 24 houses the LED board 25, the light guide unit 26, the first heat sink 27, and the fan 28.

[0028] The LED substrate 25 comprises a plurality of LED light sources 25a that emit light including ultraviolet light, and a substrate 25b. The plurality of LED light sources 25a are mounted in a two-dimensional array on the surface of the substrate 25b in the +Y direction (see Figure 8). That is, the substrate 25b on which the LED light sources 25a are mounted is referred to as the LED substrate 25. The number of LED light sources 25a can be, for example, 20 or more. The LED light source 25a is a UV-LED that emits ultraviolet light having an emission peak in the wavelength range of, for example, 308 nm to 370 nm. The ultraviolet light emitted from this LED light source 25a is therapeutic light for treating skin diseases.

[0029] For example, medium-wave ultraviolet light (wavelength 308nm-313nm) is known to be effective for psoriasis, parapsoriasis, palmoplantar pustulosis, malignant lymphoma, mycosis fungoides, chronic lichenoid pityriasis, vitiligo, and atopic dermatitis. Similarly, long-wave ultraviolet light (wavelength 340nm-400nm) is known to be effective for cutaneous T-cell lymphoma, mycosis fungoides, scleroderma, and dyshidrotic eczema. The LED light source 25a emits ultraviolet light with a wavelength corresponding to the skin disease being treated.

[0030] The LED substrate 25 is positioned so that the side on which the LED light source 25a is mounted faces the light emission window 23. The LED substrate 25 uses metal for the substrate base or core in order to efficiently conduct heat from the mounted components (LED light source 25a) to the first heat sink 27. Here, metals with high thermal conductivity such as aluminum or copper can be used for the substrate base or core.

[0031] The light guide section 26 is a light guide path that guides the light emitted from the LED light source 25a to the light emission window 23, and is composed of a housing 24 in the section from the LED light source 25a to the light emission window 23. The inner circumferential surface of the housing 24 that constitutes the light guide section 26 may be made of a reflector. In this case, the light guide section 26 guides the light emitted from the LED light source 25a and the light reflected from the inner circumferential surface of the reflector to the light emission window 23. Furthermore, a wavelength-selective filter that transmits only light within a desired wavelength range from the light emitted by the LED light source 25a may be placed between the LED light source 25a and the light emission window 23 in the light guide section 26. [Heat sink configuration]

[0032] As described above, the UV-LEDs used as the light source in the ultraviolet therapy device 1 of the first embodiment generate heat when lit. In particular, in a two-dimensional array of multiple LED light sources 25a, the temperature of the LED light source 25a located in the center becomes higher than the temperature of the LED light sources 25a located in the periphery. If this heat generated from the UV-LEDs is not properly dissipated, phenomena such as wavelength shift (longer wavelength) of the emitted light, variations in wavelength shift on the irradiation surface due to temperature variations, and thermal damage to the LED elements may occur.

[0033] In the first embodiment, in order to prevent temperature variations between the central and peripheral parts during heat dissipation, the materials constituting the central part of the heat sink and the materials constituting the peripheral part outside the central part are made of materials with different thermal conductivity. Specifically, the material of the central part is made of a material with a higher thermal conductivity than the material of the peripheral part. [Example Configuration 1]

[0034] First, a first configuration example of the heat sink according to the first embodiment will be described based on Figures 3A(a) and (b). Figure 3A(a) is a diagram showing the schematic configuration of the first heat sink 27 according to the first configuration example of the first embodiment, and Figure 3A(b) is a cross-sectional view taken along line AA of Figure 3A(a). As shown in Figures 3A(a) and (b), the first heatsink 27 comprises a central first heatsink portion 271 enclosed by a dashed rectangle, and a peripheral second heatsink portion 272 surrounding the first heatsink portion 271.

[0035] Specifically, the first heat sink portion 271 and the multiple LED light sources 25a located in the center of the substrate 25b of the LED substrate 25 are in an overlapping positional relationship in the Y direction. In addition, the second heat sink portion 272 and the multiple LED light sources 25a located in the peripheral area of ​​the substrate 25b of the LED substrate 25 are in an overlapping positional relationship in the Y direction. The first heat sink portion 271 comprises a rectangular first base portion 271a when viewed from the +Y direction, and a plurality of first fin portions 271b provided on the side of the first base portion 271a opposite to the LED substrate 25 side. The second heat sink portion 272 comprises a second annular base portion 272a when viewed from the +Y direction, and a plurality of second fin portions 272b and a plurality of third fin portions 272c provided on the side of the second base portion 272a opposite to the LED substrate 25 side. The first base portion 271a and the second base portion 272a are integrally formed and attached to the side of the LED substrate 25 opposite to the mounting surface of the LED light source 25a.

[0036] The first heat sink section 271 and the second heat sink section 272 are each made of a metal material with relatively high thermal conductivity. Furthermore, the first heat sink section 271 is made of a metal material with higher thermal conductivity than the second heat sink section 272. For example, the first heat sink section 271 is made of copper, and the second heat sink section 272 is made of aluminum. The thermal conductivity of copper is approximately 372-398 W / m·K at room temperature (20°C), and the thermal conductivity of aluminum is approximately 236-237 W / m·K at room temperature (20°C).

[0037] In the examples shown in Figures 3A(a) and (b), the first fin portion 271b, the second fin portion 272b, and the third fin portion 272c are all plate-shaped (flat) members with the same width in the Z direction (arrangement direction). The first fin portion 271b, the second fin portion 272b, and the third fin portion 272c all extend vertically from the first base portion 271a and the second base portion 272a in the opposite direction from the LED substrate 25 (+Y direction) and extend in the Y direction. The first fin portion 271b and the second fin portion 272b all extend from one end of the first base portion 271a and the second base portion 272a in the X direction toward the other end and extend in the X direction. The third fin portion 272c extends in the X direction in part between the -X-direction end of the second base portion 272a and the second heat sink portion 272, and the other portion extends in the X direction between the -X-direction end of the second base portion 272a and the second heat sink portion 272. However, in terms of length in the X direction, the first fin portion 271b is shorter than the second fin portion 272b and longer than the third fin portion 272c. In terms of length in the Y direction, the first fin portion 271b, the second fin portion 272b, and the third fin portion 272c are all the same.

[0038] Furthermore, in the examples shown in Figures 3A(a) and (b), the seven first fin portions 271b are arranged on the first base portion 271a, with their longitudinal directions facing the X direction when viewed from the +Y direction side, and are arranged at equal intervals in the Z direction. In other words, the first fin portions 271b are arranged parallel to each other.

[0039] Similarly, the six second fin portions 272b are arranged in groups of three on the +Z direction and three on the -Z direction relative to the first heat sink portion 271 of the second base portion 272a. When viewed from the +Y direction, each of these six second fin portions 272b is positioned with its longitudinal direction facing the X direction and is spaced equally in the Z direction. In other words, the second fin portions 272b are arranged in parallel to each other.

[0040] Similarly, the 14 third fin portions 272c are arranged seven on the +X side and seven on the -X side of the second base portion 272a relative to the first heat sink portion 271. When viewed from the +Y side, the 14 third fin portions 272c are arranged with their longitudinal direction facing the X direction and are spaced equally in the Z direction. That is, the third fin portions 272c are arranged in parallel to each other. Furthermore, in the examples shown in Figures 3A(a) and (b), the spacing in the Z direction between the first fin sections 271b, the second fin sections 272b, and the third fin sections 272c is the same.

[0041] The gaps formed by the spacing between the first fin portions 271b, as well as the gaps formed by the spacing between the second fin portions 272b and the third fin portions 272c, serve as passages for the cooling air blown from the fan 28. Furthermore, the gaps formed by the spacing between the first fin portion 271b and the second fin portion 272b also serve as passages for the cooling air. [Fan 28 configuration]

[0042] The fan 28 is used to improve the heat dissipation efficiency of the first heat sink 27 by supplying cooling air to the multiple first fin portions 271b, multiple second fin portions 272b, and multiple third fin portions 272c of the first heat sink 27. In the first embodiment, the fan 28 is an axial fan. The fan 28 is mounted on the side of the first heat sink 27 opposite to the LED substrate 25, with its first intake surface facing the surface on which the first fin portions 271b, second fin portions 272b, and third fin portions 272c of the first heat sink 27 are provided. In this way, the fan 28 is positioned so that the intake and discharge directions of the airflow coincide with or substantially coincide with the arrangement direction (Y direction) of the light emission window 23, the LED substrate 25, and the first heat sink 27.

[0043] Furthermore, an air intake (not shown) is provided on the side of the housing 24 at a position corresponding to the first heat sink 27, for drawing cooling air into the housing 24. Specifically, the air intake is provided on the surface of the housing 24 facing the X direction, at positions opposite the first fin portion 271b, the second fin portion 272b, and the third fin portion 272c of the first heat sink 27. The shape of the intake port opening can be arbitrary, such as a slit or a hole arrangement. Furthermore, in order to fully utilize the characteristics of the fan 28, it is preferable that the area of ​​the intake port opening is equal to or greater than the area of ​​the fan 28's intake surface.

[0044] Furthermore, an exhaust port (not shown) is provided on the rear side of the housing 24 (the side opposite to the side on which the light emission window 23 is provided) for exhausting the cooling air blown by the fan 28 to the outside of the housing 24. Specifically, the exhaust port is located on the rear side of the housing 24, at a position opposite the first fin portion 271b, the second fin portion 272b, and the third fin portion 272c of the first heat sink 27 (at a position opposite the discharge surface of the fan 28, which is an axial flow fan). The shape of the exhaust port opening can be arbitrary, such as a slit or a hole arrangement. Furthermore, in order to fully utilize the characteristics of the fan 28, it is preferable that the area of ​​the exhaust port opening be equal to or greater than the area of ​​the discharge surface of the fan 28. [Example of configuration 2]

[0045] Next, a second configuration example of the heat sink according to the first embodiment will be described based on Figures 3B(a) and (b). Figure 3B(a) is a diagram showing the schematic configuration of the second heat sink 29 according to the second configuration example of the first embodiment, and Figure 3B(b) is a cross-sectional view of Figure 3B(a) along line BB.

[0046] The ultraviolet therapy device 1 can use the second heat sink 29 of the second configuration example instead of the first heat sink 27 of the first configuration example described above. The second heat sink 29 is an example of a configuration in which the configuration according to the first embodiment is applied to a heat sink in which a plurality of rod-shaped fins are arranged in a pincushion-like manner. As shown in Figures 3B(a) and (b), the second heatsink 29 comprises a central first heatsink portion 291 enclosed by a dashed rectangle, and a peripheral second heatsink portion 292 surrounding the first heatsink portion 291.

[0047] Specifically, the first heat sink portion 291 and the multiple LED light sources 25a located in the center of the substrate 25b of the LED substrate 25 are in an overlapping positional relationship in the Y direction. In addition, the second heat sink portion 292 and the multiple LED light sources 25a located in the peripheral area of ​​the substrate 25b of the LED substrate 25 are in an overlapping positional relationship in the Y direction. The first heat sink portion 291 comprises a rectangular first base portion 291a when viewed from the +Y direction, and a plurality of first fin portions 291b provided on the side of the first base portion 291a opposite to the LED substrate 25 side. The second heat sink portion 292 comprises a second annular base portion 292a when viewed from the +Y direction, and a plurality of second fin portions 292b provided on the side of the second base portion 292a opposite to the LED substrate 25 side. The first base portion 291a and the second base portion 292a are integrally formed and attached to the side of the LED substrate 25 opposite to the mounting surface of the LED light source 25a.

[0048] The first heat sink section 291 and the second heat sink section 292 are each made of a metal material with relatively high thermal conductivity. Furthermore, the first heat sink section 291 is made of a metal material with higher thermal conductivity than the second heat sink section 292. For example, the first heat sink section 291 is made of copper, and the second heat sink section 292 is made of aluminum, for example.

[0049] In the examples shown in Figures 3B(a) and (b), the multiple first fin portions 291b and the multiple second fin portions 292b are all prismatic members with the same width in the X and Z directions. That is, each first fin portion 291b and each second fin portion 292b extends vertically from the first base portion 291a and the second base portion 292a in the direction opposite to the LED substrate 25 (+Y direction) and extends in the Y direction. In the examples shown in Figures 3B(a) and (b), the lengths of the first fin portions 291b and the second fin portions 292b in the Y direction are all the same. Furthermore, in the examples shown in Figures 3B(a) and (b), 30 first fin portions 291b are arranged on the first base portion 291a at equal intervals in the X and Z directions. That is, the first fin portions 291b are arranged parallel to each other in the X and Z directions.

[0050] Similarly, the 96 second fin portions 292b are arranged at equal intervals in the X and Z directions, with 33 fins each on the +Z direction side and -Z direction side of the second base portion 292a relative to the first heat sink portion 291. Furthermore, 15 fins each are arranged at equal intervals in the X and Z directions on the +X direction side and -X direction side of the second base portion 292a relative to the first heat sink portion 291. In other words, the second fin portions 292b are arranged parallel to each other in the X and Z directions. Furthermore, in the examples shown in Figures 3B(a) and (b), the distance between the first fin portion 291b and the second fin portion 292b is the same in both cases.

[0051] The gaps formed by the spacing between the first fin sections 291b and the gaps formed by the spacing between the second fin sections 292b serve as passages for the cooling air blown from the fan 28. Similarly, the gaps formed by the spacing between the first fin section 291b and the second fin section 292b also serve as passages for the cooling air. [Effects of the First Embodiment]

[0052] As described above, the ultraviolet therapy device 1 of the first embodiment includes a first heat sink 27 or a second heat sink 29 and a fan 28 as components for dissipating heat generated by a plurality of LED light sources 25a arranged in a two-dimensional array. Both the first heat sink 27 and the second heat sink 29 include a first heat sink portion 271 (291) in the center and a second heat sink portion 272 (292) in the periphery. The first heat sink portion 271 (291) is made of a material with higher thermal conductivity than the second heat sink portion 272 (292). That is, the first base portion 271a (291a) is made of a material with higher thermal conductivity than the second base portion 272a (292a). In addition, the plurality of first fin portions 271b (291b) are made of a material with higher thermal conductivity than the plurality of second fin portions 272b (292b) and the plurality of third fin portions 272c.

[0053] With this configuration, the heat dissipation efficiency of the first heat sink section 271 (291) is higher than that of the second heat sink section 272 (292). As a result, the amount of heat dissipated from the heat generated by the multiple LED light sources 25a in the central section can be made larger compared to the amount of heat dissipated from the heat generated by the multiple LED light sources 25a in the peripheral section, so that heat can be dissipated in a balanced manner between the central and peripheral sections. As a result, the temperature variation of the multiple LED light sources 25a on the LED substrate 25 when they are lit can be reduced. [Correspondence in the first embodiment] In the first embodiment described above, the first base portion 271a and the second base portion 272a, as well as the first base portion 291a and the second base portion 292a, correspond to the heat sink base, and the fan 28 corresponds to the blower. Furthermore, in the first embodiment described above, the first base portions 271a and 291a correspond to a part of the heat sink base, and the second base portions 272a and 292a correspond to the other part of the heat sink base. Furthermore, in the first embodiment described above, the plurality of first fin portions 271b provided on the first base portion 271a and the plurality of first fin portions 291b provided on the first base portion 291a correspond to the first group. Furthermore, in the first embodiment described above, the plurality of second fin portions 272b provided on the second base portion 272a and the plurality of second fin portions 292b provided on the second base portion 292a correspond to the second group. [Second Embodiment] Next, a second embodiment of the present invention will be described with reference to the drawings. Figures 4(a) and 4(b) show the second embodiment. The second embodiment differs from the first embodiment in that the density per unit area of ​​the multiple fins in the central part is made greater than the density per unit area of ​​the multiple fins in the peripheral part, thereby increasing the heat dissipation capacity (heat dissipation efficiency) of the central part compared to the peripheral part. The following describes in detail the parts that differ from the first embodiment described above, and the explanations of overlapping parts will be omitted as appropriate. Figure 4(a) is a diagram showing the schematic configuration of the third heat sink 27A according to the first configuration example of the second embodiment, and Figure 4(b) is a diagram showing the schematic configuration of the fourth heat sink 29A according to the second configuration example of the second embodiment. [Example Configuration 1] The ultraviolet therapy device 1 according to the first configuration example of the second embodiment is equipped with a third heat sink 27A in place of the first heat sink 27 or second heat sink 29 of the first embodiment, as shown in Figure 4(a). The third heatsink 27A comprises a base portion 272Aa, a first fin group 273, and a second fin group 274. The base portion 272Aa has a rectangular shape when viewed from the +Y direction and is attached to the side of the LED substrate 25 opposite to the mounting surface of the LED light source 25a.

[0054] The first fin group 273 is a group consisting of multiple first fin portions 273b provided in the central part of the base portion 272Aa, as shown in the area enclosed by the dashed rectangle in Figure 4(a). The first fin group 273 is provided on the side of the central part of the base portion 272Aa that is opposite to the LED substrate 25 side.

[0055] The second fin group 274 is a group consisting of a plurality of second fin portions 272b and a plurality of third fin portions 272c provided on the outer peripheral portion of the base portion 272Aa, outside the first fin group 273. The second fin group 274 is provided on the peripheral portion of the base portion 272Aa on the side opposite to the LED substrate 25.

[0056] The first fin group 273 and the multiple LED light sources 25a located in the center of the substrate 25b of the LED substrate 25 are in a positional relationship that overlaps in the Y direction. In addition, the second fin group 274 and the multiple LED light sources 25a located in the periphery of the substrate 25b of the LED substrate 25 are in a positional relationship that overlaps in the Y direction.

[0057] In the example shown in Figure 4(a), the first fin section 273b, the second fin section 272b, and the third fin section 272c are all plate-shaped (flat) members with the same width in the Z direction. The first fin section 273b, the second fin section 272b, and the third fin section 272c all extend in the X and Y directions. However, in the X direction, the length of the first fin section 273b is shorter than that of the second fin section 272b and longer than that of the third fin section 272c. In the Y direction, the lengths of the first fin section 273b, the second fin section 272b, and the third fin section 272c are all the same. Furthermore, in the example shown in Figure 4(a), the eight first fin portions 273b are arranged on the central part of the base portion 272Aa, with their longitudinal direction facing the X direction when viewed from the +Y direction side, and are arranged at equal intervals in the Z direction. In other words, the first fin portions 273b are arranged in parallel to each other.

[0058] Similarly, the eight second fin sections 272b are positioned four each on the +Z side and -Z side of the base section 272a relative to the first fin group 273. These eight second fin sections 272b are positioned with their longitudinal direction facing the X direction when viewed from the +Y direction, and are spaced equally in the Z direction. In other words, the second fin sections 272b are arranged parallel to each other.

[0059] Similarly, the ten third fin sections 272c are arranged five on the +X side and five on the -X side of the base section 272Aa relative to the first fin group 273. These ten third fin sections 272c are arranged with their longitudinal direction facing the X direction when viewed from the +Y direction, and are spaced equally in the Z direction. That is, the third fin sections 272c are arranged parallel to each other. In the example shown in Figure 4(a), the spacing between the first fin portions 273b in the Z direction is narrower than the spacing between the second fin portions 272b and the third fin portions 272c in the Z direction.

[0060] In other words, the density of the first fin portion 273b per unit area of ​​the base portion 272Aa facing the first fin group 273 is greater than the density of the second fin portion 272b and the third fin portion 272c per unit area of ​​the base portion 272Aa facing the second fin group 274. To put it another way, the total surface area of ​​the first fin portion 273b per unit area of ​​the first fin group 273 is greater than the total surface area of ​​the second fin portion 272b or the third fin portion 272c per unit area of ​​the second fin group 274. As a result, the heat dissipation efficiency of the first fin portion 273b per unit area of ​​the first fin group 273 is higher than the heat dissipation efficiency of the second fin portion 272b or the third fin portion 272c per unit area of ​​the second fin group 274.

[0061] Here, the total surface area per unit area is calculated based on the areas of the five faces of each fin: the face facing the +Y direction, the face facing the +Z direction, the face facing the -Z direction, the face facing the +X direction, and the face facing the -X direction. In other words, it is the sum of the areas of all or part of the faces included in the unit area from the five faces of each fin.

[0062] Furthermore, the calculation of surface area is not limited to all five faces. For example, in the case of a flat fin, the total surface area per unit area may be calculated based on the areas of the two faces that are the widest, the face facing the +Z direction and the face facing the -Z direction. Similarly, in the case of a prismatic fin, the total surface area per unit area may be calculated based on the areas of the four faces that are facing the +Z direction, the face facing the -Z direction, the face facing the +X direction, and the face facing the -X direction. In addition, for example, in the case of a cylindrical fin, the total surface area per unit area may be calculated based on the areas of the bottom and sides, or it may be calculated based on the area of ​​only the sides.

[0063] Furthermore, the gaps formed by the spacing between the first fin sections 273b, and the gaps formed by the spacing between the second fin sections 272b and the third fin sections 272c, serve as passages for the cooling air blown from the fan 28. Similarly, the gaps formed by the spacing between the first fin section 273b and the second fin section 272b, and the gaps formed by the spacing between the second fin section 272b and the third fin section 272c, also serve as passages for the cooling air. In other words, when narrowing the spacing between the fin portions 271b of the first fin group 273 to increase density, this spacing is designed to be such that it does not obstruct the flow of cooling air necessary for heat dissipation. [Example of configuration 2] The ultraviolet therapy device 1 according to the second configuration example of the second embodiment is equipped with a fourth heat sink 29A in place of the first heat sink 27 or second heat sink 29 of the first embodiment, as shown in Figure 4(b). The fourth heatsink 29A comprises a base portion 29Aa, a first fin group 293, and a second fin group 294. The base portion 29Aa has a rectangular shape when viewed from the +Y direction and is attached to the side of the LED substrate 25 opposite to the mounting surface of the LED light source 25a.

[0064] The first fin group 293 is a group consisting of multiple fin portions 29b provided in the central part of the base portion 29Aa, as shown in the area enclosed by the dashed rectangle in Figure 4(b). The first fin group 293 is provided on the side of the central part of the base portion 29Aa that is opposite to the LED substrate 25 side.

[0065] The second fin group 294 is a group consisting of multiple fin portions 29b provided on the outer peripheral portion of the base portion 272Aa, outside the first fin group 273. The second fin group 294 is provided on the peripheral portion of the base portion 29Aa on the side opposite to the LED substrate 25.

[0066] Specifically, the first fin group 293 and the multiple LED light sources 25a located in the center of the substrate 25b of the LED substrate 25 are in an overlapping positional relationship in the Y direction. In addition, the second fin group 294 and the multiple LED light sources 25a located in the periphery of the substrate 25b of the LED substrate 25 are in an overlapping positional relationship in the Y direction. In the example shown in Figure 4(b), each fin portion 29b is a prismatic member with the same width in the X and Z directions. That is, each fin portion 29b extends vertically in the +Y direction from the surface of the base portion 29Aa opposite to the LED substrate 25 side and extends in the Y direction. In the example shown in Figure 4(b), the 35 fin sections 29b are arranged at equal intervals in the X and Z directions on the central part of the base section 29Aa. That is, the fin sections 29b are arranged in parallel to each other.

[0067] Similarly, 88 fin sections 29b are arranged at equal intervals in the X and Z directions, 44 each, on the +Z and -Z directions relative to the first fin group 293 of the base section 29Aa. That is, these fin sections 29b are arranged in parallel. Furthermore, 24 fin sections 29b are arranged at equal intervals in the X and Z directions, 12 each, on the +X and -X directions relative to the first fin group 293 of the base section 29Aa. That is, these fin sections 29b are arranged in parallel. Furthermore, in the example shown in Figure 4(b), the spacing between the multiple fin portions 29b of the first fin group 293 in the X and Z directions is narrower than the spacing between the multiple fin portions 29b of the second fin group 294 in the X and Z directions.

[0068] In other words, the density of fin portions 29b per unit area of ​​the base portion 29Aa facing the first fin group 293 is greater than the density of fin portions 29b per unit area of ​​the base portion 29Aa facing the second fin group 294. To put it another way, the total surface area of ​​fin portions 29b per unit area of ​​the first fin group 293 is greater than the total surface area of ​​fin portions 29b per unit area of ​​the second fin group 294. As a result, the heat dissipation efficiency of fin portions 29b per unit area of ​​the first fin group 293 is higher than the heat dissipation efficiency of fin portions 29b per unit area of ​​the second fin group 294.

[0069] Furthermore, the gaps formed by the spacing between the fin portions 29b of the first fin group 293, and the gaps formed by the spacing between the fin portions 29b of the second fin group 294, serve as passages for the cooling air blown from the fan 28. Similarly, the gaps formed by the spacing between the fin portions 29b of the first fin group 293 and the fin portions 29b of the second fin group 294 also serve as passages for the cooling air. In other words, when narrowing the spacing between the fin portions 29b of the first fin group 293 to increase density, this spacing is designed to be such that it does not obstruct the flow of cooling air necessary for heat dissipation. [Effects of the second embodiment]

[0070] As described above, the ultraviolet therapy device 1 of the second embodiment is equipped with a third heat sink 27A or a fourth heat sink 29A in place of the first heat sink 27 or the second heat sink 29 in the ultraviolet therapy device 1 of the first embodiment. Both the third heat sink 27A and the fourth heat sink 29A are equipped with a first fin group 273(293) in the center and a second fin group 274(294) in the periphery. The first fin group 273(293) is configured to have a higher density of fins per unit area than the second fin group 274(294). That is, the total surface area of ​​fins per unit area of ​​the first fin group 273(293) is larger than that of the second fin group 274(294).

[0071] With this configuration, the heat dissipation efficiency of the first fin group 273 (293) can be made higher than that of the second fin group 274 (294). As a result, the amount of heat dissipated from the heat generated by the multiple LED light sources 25a in the central part can be made larger compared to the amount of heat dissipated from the heat generated by the multiple LED light sources 25a in the peripheral part, so that heat can be dissipated in a balanced manner between the central and peripheral parts. As a result, the temperature variation of the multiple LED light sources 25a on the LED substrate 25 when they are lit can be reduced. [Correspondence in the second embodiment] In the second embodiment described above, the base portions 272Aa and 29Aa correspond to the heat sink base, the first fin groups 273 and 293 correspond to the first group, and the second fin groups 274 and 294 correspond to the second group. (Third embodiment) Next, a third embodiment of the present invention will be described with reference to the drawings. Figures 5(a) and 5(b) show the third embodiment. The third embodiment differs from the second embodiment in that it increases the heat dissipation capacity of the central part by continuously and gradually increasing the total surface area per unit area of ​​the fin part as you move from the edge of the base part towards the center part. The following describes in detail the differences from the second embodiment described above, and the explanations of overlapping parts will be omitted as appropriate. Figure 5(a) is a diagram showing the schematic configuration of the fifth heat sink 27B according to the first configuration example of the third embodiment, and Figure 5(b) is a diagram showing the schematic configuration of the sixth heat sink 29B according to the second configuration example of the third embodiment. [Example Configuration 1] The ultraviolet therapy device 1 according to the first configuration example of the third embodiment is equipped with a fifth heat sink 27B in place of the third heat sink 27A or fourth heat sink 29A of the second embodiment, as shown in Figure 5(a). The fifth heatsink 27B comprises a base portion 272Aa, a first fin group 273B, and a second fin group 274B. The base portion 272Aa has a rectangular shape when viewed from the +Y direction and is attached to the side of the LED substrate 25 opposite to the mounting surface of the LED light source 25a.

[0072] The first fin group 273B is a group consisting of multiple fin portions 272b provided in the central part of the base portion 272Aa in the Z direction, as shown in the area enclosed by the dashed rectangle in Figure 5(a). The first fin group 273B is provided on the side of the base portion 272Aa opposite to the LED substrate 25 side in the central part of the base portion 272Aa in the Z direction.

[0073] The second fin group 274B is a group consisting of multiple fin portions 272b provided on the peripheral portions of the first fin group 273B of the base portion 272Aa on the +Z and -Z directions. The second fin group 274B is provided on the side of the base portion 272Aa on the peripheral portions on the +Z and -Z directions that is opposite to the LED substrate 25 side.

[0074] Specifically, the multiple fin portions 272b that make up the first fin group 273B and the second fin group 274B are configured such that the spacing between the fin portions 272b gradually narrows as you move from the +Z-direction end and -Z-direction end of the base portion 272Aa towards the center.

[0075] Here, as illustrated in Figure 5(a), let d1 be the distance between the first and second fin sections 272b from the end in the +Z direction. Similarly, let d2 be the distance between the fourth and fifth fin sections 272b from the end in the +Z direction. Similarly, let d3 be the distance between the sixth and seventh fin sections 272b from the end in the +Z direction. These distances d1 to d3 have the relationship "d1 > d2 > d3". This relationship is also true for the distances between fin sections 272b from the end in the -Z direction towards the center.

[0076] In the first configuration example, the first fin group 273B consists of seven central fin sections 272b where the spacing between the fin sections 272b in the Z direction is shorter than the spacing d2. The second fin group 274B consists of the remaining eight fin sections 272b, excluding the seven central fin sections 272b.

[0077] The central portion of the first fin group 273B in the X direction and the multiple LED light sources 25a located in the central portion of the substrate 25b of the LED substrate 25 are in an overlapping positional relationship in the Y direction. In addition, the portions of the first fin group 273B outside the central portion and the multiple LED light sources 25a located in the peripheral portion of the second fin group 274B and the substrate 25b of the LED substrate 25 are in an overlapping positional relationship in the Y direction.

[0078] In other words, the density of fin portions 272b per unit area of ​​the base portion 272Aa facing the first fin group 273B is greater than the density of fin portions 272b per unit area of ​​the base portion 272Aa facing the second fin group 274B. To put it another way, the total surface area of ​​fin portions 272b per unit area of ​​the first fin group 273B is greater than the total surface area of ​​fin portions 272b per unit area of ​​the second fin group 274B. As a result, the heat dissipation efficiency of fin portions 272b per unit area of ​​the first fin group 273B is higher than the heat dissipation efficiency of fin portions 272b per unit area of ​​the second fin group 274B. Furthermore, since the spacing between the multiple fin sections 272b gradually narrows from the +Z and -Z ends towards the center, the heat dissipation efficiency can be increased stepwise from the +Z and -Z ends towards the center. Furthermore, the gaps formed by the spacing between the fin portions 272b serve as a flow path for the cooling air blown from the fan 28. In other words, the spacing between the fin portions 272b of the first fin group 273B is designed to be such that it does not obstruct the flow of cooling air necessary for heat dissipation. [Example of configuration 2] The ultraviolet therapy device 1 according to the second configuration example of the third embodiment is equipped with a sixth heat sink 29B in place of the third heat sink 27A or fourth heat sink 29A of the second embodiment, as shown in Figure 5(b). The sixth heatsink 29B comprises a base portion 29Aa, a first fin group 293B, and a second fin group 294B. The base portion 29Aa has a rectangular shape when viewed from the +Y direction and is attached to the side of the LED substrate 25 opposite to the mounting surface of the LED light source 25a.

[0079] The first fin group 293B is a group consisting of multiple fin sections 29b provided in the central part of the base section 29Aa, as shown in the area enclosed by the dashed rectangle in Figure 5(b). The first fin group 293B is provided on the side of the central part of the base section 29Aa that is opposite to the LED substrate 25 side.

[0080] The second fin group 294B is a group consisting of multiple fin portions 29b provided in the peripheral portion surrounding the first fin group 293B of the base portion 29Aa. The second fin group 294B is provided on the side of the peripheral portion of the base portion 29Aa that is opposite to the LED substrate 25 side.

[0081] Specifically, the multiple fin portions 29b constituting the first fin group 293B and the second fin group 294B are configured such that the spacing between the fin portions 29b gradually narrows as you move from the +Z-direction end and the -Z-direction end of the base portion 29Aa towards the center. In addition, the multiple fin portions 29b constituting the first fin group 293B and the second fin group 294B are configured such that the spacing between the fin portions 29b gradually narrows as you move from the +X-direction end and the -X-direction end of the base portion 29Aa towards the center.

[0082] Here, as illustrated in Figure 5(b), let d5 be the distance between the first and second fin sections 29b from the end in the -Z direction. Similarly, let d6 be the distance between the fourth and fifth fin sections 29b from the end in the -Z direction. The relationship between these distances d5 and d6 is "d5 > d6". This relationship is also true for the distances between the fin sections 29b from the end in the +Z direction towards the center.

[0083] On the other hand, let d7 be the distance between the first and second fin sections 29b from the end in the -X direction. Similarly, let d8 be the distance between the fourth and fifth fin sections 29b from the end in the -X direction. Similarly, let d9 be the distance between the seventh and eighth fin sections 29b from the end in the -X direction. These distances d7 to d9 satisfy the relationship "d7 > d8 > d9". This relationship is also true for the distances between fin sections 29b from the end in the +X direction towards the center.

[0084] In the second configuration example, the first fin group 293B consists of 35 central fin portions 29b where the spacing between fin portions 29b in the Z direction is d6 or less, and the spacing between fin portions 29b in the X direction is d8 or less. The second fin group 294B consists of the remaining 114 fin portions 29b, excluding the 35 central fin portions 29b.

[0085] The first fin group 293B and the multiple LED light sources 25a located in the center of the substrate 25b of the LED substrate 25 are in a positional relationship that overlaps in the Y direction. In addition, the second fin group 294B and the multiple LED light sources 25a located in the periphery of the substrate 25b of the LED substrate 25 are in a positional relationship that overlaps in the Y direction.

[0086] In other words, the density of fin portions 29b per unit area of ​​the base portion 29Aa facing the first fin group 293B is greater than the density of fin portions 29b per unit area of ​​the base portion 29Aa facing the second fin group 294B. To put it another way, the total surface area of ​​fin portions 29b per unit area of ​​the first fin group 293B is greater than the total surface area of ​​fin portions 29b per unit area of ​​the second fin group 294B. As a result, the heat dissipation efficiency of fin portions 272b per unit area of ​​the first fin group 273B is higher than the heat dissipation efficiency of fin portions 272b per unit area of ​​the second fin group 274B.

[0087] Furthermore, the spacing between the multiple fin sections 29b gradually narrows in the Z direction as you move from the +Z and -Z ends towards the center, and gradually narrows in the X direction as you move from the +X and -X ends towards the center. This allows for a gradual increase in heat dissipation efficiency as you move from the ends in the X and Z directions towards the center. Furthermore, the gaps formed by the spacing between the fin portions 29b serve as a flow path for the cooling air blown from the fan 28. In other words, the spacing between the fin portions 29b of the first fin group 293B is designed to be such that it does not obstruct the flow of cooling air necessary for heat dissipation. [Effects of the third embodiment]

[0088] As described above, the ultraviolet therapy device 1 of the third embodiment is equipped with a fifth heat sink 27B or a sixth heat sink 29B in place of the third heat sink 27A or fourth heat sink 29A in the ultraviolet therapy device 1 of the second embodiment. Both the fifth heat sink 27B and the sixth heat sink 29B are configured such that the spacing between the fin portions 272b(29b) gradually narrows from the end of the base portion 272Aa(29Aa) toward the center. In other words, the first fin group 273B(293B) is configured such that the density of fin portions per unit area of ​​the base portion 272Aa(29Aa) is greater than that of the second fin group 274B(294B). In other words, the total surface area of ​​fin portions per unit area of ​​the base portion 272Aa(29Aa) is greater in the first fin group 273B(293B) than in the second fin group 274B(294B).

[0089] With this configuration, the heat dissipation efficiency of the first fin group 273B (293B) is higher than that of the second fin group 274B (294B). As a result, the amount of heat dissipated from the multiple LED light sources 25a in the central part can be made larger compared to the amount of heat dissipated from the multiple LED light sources 25a in the peripheral part, so that heat dissipation can be balanced between the central and peripheral parts. As a result, the temperature variation of the multiple LED light sources 25a on the LED substrate 25 when they are lit can be reduced. [Correspondence in the third embodiment] In the third embodiment described above, the base portions 272Aa and 29Aa correspond to the heat sink base, the first fin groups 273B and 293B correspond to the first group, and the second fin groups 274B and 294B correspond to the second group. [Fourth Embodiment] 〔composition〕 Next, a fourth embodiment of the present invention will be described with reference to the drawings. Figures 6(a) and 6(b) show the fourth embodiment. The fourth embodiment differs from the second embodiment in that the width of the multiple fin sections located in the central part is changed so that the number of multiple fin sections per unit area located in the central part is greater than the number of multiple fin sections per unit area located in the peripheral part. The following describes in detail the differences from the second embodiment described above, and the explanations of overlapping parts will be omitted as appropriate. Figure 6(a) is a diagram showing the schematic configuration of the seventh heatsink 27C according to the first configuration example of the fourth embodiment, and Figure 6(b) is a diagram showing the schematic configuration of the eighth heatsink 29C according to the second configuration example of the fourth embodiment. [Example Configuration 1] The ultraviolet therapy device 1 according to the first configuration example of the fourth embodiment is equipped with a seventh heat sink 27C in place of the third heat sink 27A or the fourth heat sink 29A of the second embodiment, as shown in Figure 6(a). The seventh heatsink 27C comprises a base portion 272Aa, a first fin group 273C, and a second fin group 274C. The base portion 272Aa has a rectangular shape when viewed from the +Y direction and is attached to the side of the LED substrate 25 opposite to the mounting surface of the LED light source 25a.

[0090] The first fin group 273C is a group consisting of multiple first fin portions 273Cb provided in the central part of the base portion 272Aa, as shown in the area enclosed by the dashed rectangle in Figure 6(a). The first fin group 273C is provided on the side of the central part of the base portion 272Aa that is opposite to the LED substrate 25 side.

[0091] The second fin group 274C is a group consisting of a plurality of second fin portions 272Cb and a plurality of third fin portions 272Cc provided on the outer peripheral portion of the base portion 272Aa, beyond the first fin group 273C. The second fin group 274C is provided on the peripheral portion of the base portion 272Aa on the side opposite to the LED substrate 25.

[0092] The first fin group 273C and the multiple LED light sources 25a located in the center of the substrate 25b of the LED substrate 25 are in an overlapping positional relationship in the Y direction. In addition, the second fin group 274C and the multiple LED light sources 25a located in the periphery of the substrate 25b of the LED substrate 25 are in an overlapping positional relationship in the Y direction.

[0093] In the example shown in Figure 6(a), the first fin portion 273Cb, the second fin portion 272Cb, and the third fin portion 272Cc are all plate-shaped (flat) members. The width of the first fin portion 273Cb in the Z direction is narrower than the width of the second fin portion 272Cb and the third fin portion 272Cc in the Z direction. The widths of the second fin portion 272Cb and the third fin portion 272Cc in the Z direction are the same, but wider than the widths of the second fin portion 272b and the third fin portion 272c in the second embodiment described above. In terms of length in the X direction, the first fin portion 273Cb is shorter than the second fin portion 272Cb and longer than the third fin portion 272Cc. In terms of length in the Y direction, the first fin portion 273Cb, the second fin portion 272Cb, and the third fin portion 272Cc are all the same length.

[0094] Furthermore, in the example shown in Figure 6(a), the seven first fin portions 273Cb are arranged on the central part of the base portion 272Aa, with their longitudinal direction facing the X direction when viewed from the +Y direction side, and are arranged at equal intervals in the Z direction. In other words, the first fin portions 273Cb are arranged in parallel to each other.

[0095] Similarly, the eight second fin sections 272Cb are positioned four at each location on the +Z and -Z sides of the base section 272Aa relative to the first fin group 273C. These eight second fin sections 272Cb are positioned with their longitudinal direction facing the X direction when viewed from the +Y direction, and are spaced equally in the Z direction. In other words, the second fin sections 272Cb are arranged parallel to each other.

[0096] Similarly, the ten third fin sections 272Cc are arranged five on the +X side and five on the -X side of the base section 272Aa relative to the first fin group 273C. These ten third fin sections 272Cc are arranged with their longitudinal direction facing the X direction when viewed from the +Y direction, and are spaced equally in the Z direction. In other words, the third fin sections 272Cc are arranged parallel to each other.

[0097] In the example shown in Figure 6(a), the spacing between the first fin portions 273Cb is set to be the same as or approximately the same as the spacing between the second fin portions 272Cb and the third fin portions 272Cc. On the other hand, by narrowing the width of the first fin portions 273Cb in the Z direction, seven first fin portions 273Cb are arranged within the same width in the Z direction as the five third fin portions 272Cc. In other words, the number of first fin portions 273Cb per unit area of ​​the base portion 272Aa facing the first fin group 273C is greater than the number of second fin portions 272Cb and third fin portions 272Cc per unit area of ​​the base portion 272Aa facing the second fin group 274C.

[0098] Therefore, the total surface area of ​​the first fin portion 273Cb per unit area of ​​the first fin group 273C is larger than the total surface area of ​​the second fin portion 272Cb and the third fin portion 272Cc per unit area of ​​the second fin group 274C. This is because, of the total surface area of ​​the five faces of the flat first fin portion 273Cb, the area of ​​the two faces facing each other in the Z direction occupies a large portion. In other words, narrowing the width of the first fin portion 273Cb in the Z direction has little effect on the surface area, and increasing the number of fins increases the number of two faces facing each other in the Z direction, thus increasing the total surface area per unit area. As a result, heat dissipation efficiency can be improved.

[0099] Furthermore, the gaps formed by the spacing between the first fin sections 273Cb, and the gaps formed by the spacing between the second fin sections 272Cb and the third fin sections 272Cc, serve as flow paths for the cooling air blown from the fan 28. Similarly, the gaps formed by the spacing between the first fin section 273Cb and the second fin section 272Cb also serve as flow paths for the cooling air. In the first configuration example, when increasing the number of first fin sections 273Cb in the first fin group 273C, the spacing between the fin sections is configured to be approximately the same as that of the second fin group 274C, thereby creating a flow path that does not obstruct the flow of cooling air necessary for heat dissipation. [Example of configuration 2] The ultraviolet therapy device 1 according to the second configuration example of the fourth embodiment is equipped with an eighth heat sink 29C in place of the third heat sink 27A or the fourth heat sink 29A of the second embodiment, as shown in Figure 6(b). The eighth heat sink 29C comprises a base portion 29Aa, a first fin group 293C, and a second fin group 294. In other words, it is configured to have a first fin group 293C instead of the first fin group 293 of the second embodiment described above. The base portion 29Aa has a rectangular shape when viewed from the +Y direction and is attached to the side of the LED substrate 25 opposite to the mounting surface of the LED light source 25a.

[0100] The first fin group 293C is a group consisting of multiple first fin portions 293Cb provided in the central part of the base portion 29Aa, as shown in the area enclosed by the dashed rectangle in Figure 6(b). The first fin group 293C is provided on the side of the central part of the base portion 29Aa that is opposite to the LED substrate 25 side.

[0101] The second fin group 294 is a group consisting of multiple second fin portions 29b provided on the outer peripheral portion of the base portion 29Aa, outside the first fin group 293C. The second fin group 294 is provided on the peripheral portion of the base portion 29Aa on the side opposite to the LED substrate 25.

[0102] Specifically, the first fin group 293C and the multiple LED light sources 25a located in the center of the substrate 25b of the LED substrate 25 are in an overlapping positional relationship in the Y direction. In addition, the second fin group 294 and the multiple LED light sources 25a located in the periphery of the substrate 25b of the LED substrate 25 are in an overlapping positional relationship in the Y direction.

[0103] In the example shown in Figure 6(b), each first fin portion 293Cb and each second fin portion 29b are prismatic members with the same width in the X and Z directions. That is, each first fin portion 293Cb and each second fin portion 29b extend vertically in the +Y direction from the surface of the base portion 29Aa opposite to the LED substrate 25 side and extend in the Y direction. However, the width of each first fin portion 293Cb in the X and Z directions is smaller than the width of each second fin portion 29b in the X and Z directions. Furthermore, in the example shown in Figure 6(b), 54 first fin portions 293Cb are arranged on the central part of the base portion 29Aa at equal intervals in the X and Z directions. That is, the first fin portions 293Cb are arranged in parallel to each other.

[0104] Similarly, 88 second fin portions 29b are arranged 44 each on the +Z side and -Z side relative to the first fin group 293C of the base portion 29Aa. These second fin portions 29b are arranged at equal intervals in the X and Z directions, respectively. That is, the second fin portions 29b are arranged parallel to each other.

[0105] Similarly, 24 second fin portions 29b are arranged on the base portion 29Aa, 12 on the +X side and 12 on the -X side relative to the first fin group 293C. These second fin portions 29b are arranged at equal intervals in the X and Z directions, respectively. That is, the second fin portions 29b are arranged parallel to each other.

[0106] Furthermore, in the example shown in Figure 6(b), the spacing between multiple first fin portions 293Cb of the first fin group 293C is the same as or approximately the same as the spacing between multiple second fin portions 29b of the second fin group 294. On the other hand, the first fin group 293C has a configuration in which more first fin portions 293Cb are arranged in the same central space as the first fin group 293 of the second embodiment, by reducing the width of each first fin portion 293Cb in the X and Z directions. Specifically, it has a configuration in which 54 first fin portions 29Cb are arranged compared to 35 fin portions 29b of the second embodiment. In other words, the number of first fin portions 293Cb per unit area of ​​the base portion 29Aa facing the first fin group 293C is greater than the number of second fin portions 29b per unit area of ​​the base portion 29Aa facing the second fin group 294.

[0107] Therefore, the total surface area of ​​the first fin portion 293Cb per unit area of ​​the base portion 29Aa of the first fin group 293C is greater than the total surface area of ​​the second fin portion 29b per unit area of ​​the base portion 29Aa of the second fin group 274. This is because, of the total surface area of ​​the five faces of the columnar first fin portion 293Cb, the area of ​​the four faces facing the X and Z directions occupies a large portion. In other words, even if the width in the X and Z directions is narrowed, increasing the number of faces facing the X and Z directions increases the total surface area per unit area. As a result, heat dissipation efficiency can be improved.

[0108] Here, we will explain specific numerical examples based on experimental results. In this experiment, the first fin group 293C was configured with 196 first fin sections 293Cb, each 21.5 mm high and 1.45 mm wide in the X and Z directions, arranged per unit area (50 mm × 50 mm) on a base section 29Aa with a thickness of 3.5 mm. In addition, the second fin group 294 was configured with 61 second fin sections 29b, each 21.5 mm high and 2.3 mm wide in the X and Z directions, arranged per unit area (50 mm × 50 mm) on a base section 29Aa with a thickness of 3.5 mm. Both are made of aluminum alloy (A6063). With this configuration, the total surface area of ​​the first fin section 293Cb per unit area of ​​the first fin group 293C is approximately 24,853 mm². 2 As a result, the thermal resistance of the ultraviolet therapy device 1 when operated with a fan speed of 2 m / s was 0.8 °C / W. On the other hand, the total surface area of ​​the second fin portion 29b per unit area of ​​the second fin group 294 was approximately 12,388 mm². 2 As a result, the thermal resistance of the ultraviolet therapy device 1 when operated with a fan speed of 2 m / s was 1.2 °C / W. Furthermore, the ratio of the total surface area of ​​the fin sections of both devices was approximately 2.0.

[0109] From the above, it is possible to increase the total surface area of ​​the fins per unit area (approximately twice as much in the experiment) by reducing the width of the fins and increasing the number of fins per unit area (approximately three times as much in the experiment). Furthermore, increasing the total surface area can reduce thermal resistance and improve heat dissipation capacity.

[0110] Furthermore, the gaps formed by the spacing between the first fin portions 293Cb of the first fin group 293C, and the gaps formed by the spacing between the fin portions 29b of the second fin group 294, serve as flow paths for the cooling air blown from the fan 28. Similarly, the gaps formed by the spacing between the first fin portions 293Cb of the first fin group 293C and the fin portions 29b of the second fin group 294 also serve as flow paths for the cooling air. In the second configuration example, when increasing the number of first fin portions 293Cb of the first fin group 293C, the spacing between the fin portions is configured to be approximately the same as that of the second fin group 294C, thereby creating a flow path that does not obstruct the flow of cooling air necessary for heat dissipation. [Effects of the fourth embodiment]

[0111] As described above, the ultraviolet therapy device 1 of the fourth embodiment is equipped with a seventh heat sink 27C or an eighth heat sink 29C in place of the third heat sink 27A or fourth heat sink 29A in the ultraviolet therapy device 1 of the second embodiment. Both the seventh heat sink 27C and the eighth heat sink 29C are equipped with a first fin group 273C (293C) in the center and a second fin group 274C (294) in the periphery. Furthermore, the number of fins per unit area of ​​the base portion 272Aa (29Aa) of the first fin group 273C (293C) is configured to be greater than the number of fins per unit area of ​​the base portion 272Aa (29Aa) of the second fin group 274C (294). In other words, the total surface area of ​​the fins per unit area of ​​the first fin group 273C (293) is greater than that of the second fin group 274C (294).

[0112] With this configuration, the heat dissipation efficiency of the first fin group 273C (293C) is higher than that of the second fin group 274 (294). As a result, the amount of heat dissipated from the multiple LED light sources 25a in the central part can be made larger compared to the amount of heat dissipated from the multiple LED light sources 25a in the peripheral part, so that heat dissipation can be balanced between the central and peripheral parts. Consequently, the temperature variation of the multiple LED light sources 25a on the LED substrate 25 when they are lit can be reduced. [Correspondence in the fourth embodiment] In the fourth embodiment described above, the base portions 272Aa and 29Aa correspond to the heat sink base, the first fin groups 273C and 293C correspond to the first group, and the second fin groups 274C and 294 correspond to the second group. [Fifth Embodiment] 〔composition〕 Next, a fifth embodiment of the present invention will be described with reference to the drawings. Figure 7 shows the fifth embodiment. The fifth embodiment differs from the first embodiment in that the first heat sink and the second heat sink are separate components, and the first heat sink is detachably attached to the second heat sink. The following describes in detail the parts that differ from the first embodiment described above, and the explanations of overlapping parts will be omitted as appropriate. Figure 7 shows a schematic configuration of the ninth heatsink 27D according to the fifth embodiment. As shown in Figure 7, the ninth heatsink 27D comprises a first heatsink section 271D and a second heatsink section 272D. The first heatsink section 271D and the second heatsink section 272D are constructed as separate components. The first heat sink portion 271D comprises a rectangular first base portion 271a when viewed from the +Y direction, and a plurality of first fin portions 271b provided on the first base portion 271a.

[0113] The second heat sink portion 272D comprises a second base portion 272a that is angular and annular when viewed from the +Y direction, and a plurality of second fin portions 272b and a plurality of third fin portions 272c provided on the second base portion 272a. The second base portion 272a has an opening 272h for attaching the first heat sink portion 271D to the second heat sink portion 272D.

[0114] The inner diameter of the opening 272h of the second heat sink portion 272D is set to be approximately the same as the outer diameter of the first base portion 271a of the first heat sink portion 271D. As a result, the first heat sink portion 271D can be fitted inside the opening 272h of the second heat sink portion 272D, as shown by the arrow in Figure 7. This fitting allows for the construction of a ninth heat sink 27D having the same configuration as the first heat sink 27 of the first embodiment. Furthermore, the first heat sink section 271D is configured to be detachably attached to the second heat sink section 272D. Furthermore, although the first heat sink section 271D and the second heat sink section 272D are separate components, they have the same configuration as the first heat sink section 271 and the second heat sink section 272D of the first embodiment and are made of the same metal material. In other words, the first heat sink section 271D is made of a metal material with a higher thermal conductivity than the second heat sink section 272D.

[0115] Furthermore, in the example shown in Figure 7, the spacing between the first fin sections 271b, the second fin sections 272b, and the third fin sections 272c is the same. The gaps formed by the spacing between the first fin sections 271b, and the gaps formed by the spacing between the second fin sections 272b and the third fin sections 272c, become passages for the cooling air blown from the fan 28. Similarly, the gap formed by the spacing between the first fin section 271b and the second fin section 272b also becomes a passage for the cooling air. [Effects of the Fifth Embodiment]

[0116] As described above, the ultraviolet therapy device 1 of the fifth embodiment is configured such that the first heat sink section 271D and the second heat sink section 272D are separate components, and the first heat sink section 271D is detachably attached to the second heat sink section 272D. Furthermore, the first heat sink section 271D is made of a material with a higher thermal conductivity than the second heat sink section 272D.

[0117] With this configuration, the heat dissipation efficiency of the first heat sink section 271D can be made higher than that of the second heat sink section 272D. As a result, the amount of heat dissipated from the heat generated by the multiple LED light sources 25a in the central section can be made larger compared to the amount of heat dissipated from the heat generated by the multiple LED light sources 25a in the peripheral section, so that heat can be dissipated in a balanced manner between the central and peripheral sections. As a result, the temperature variation of the multiple LED light sources 25a on the LED substrate 25 when they are lit can be reduced.

[0118] Furthermore, since the first heat sink section 271D is configured to be detachable from the second heat sink section 272D, it is possible to attach other first heat sink sections 271D made of different metal materials or other first heat sink sections 271D with different structures. This allows for an optimal combination tailored to the usage scenario, thereby more effectively reducing temperature variations when the multiple LED light sources 25a on the LED substrate 25 are lit. [Correspondence in the fifth embodiment] In the fifth embodiment described above, the first base portion 271a and the second base portion 272a correspond to the heat sink base. Furthermore, in the fifth embodiment described above, the first base portion 271a corresponds to a part of the heat sink base, and the second base portion 272a corresponds to the other part of the heat sink base. Furthermore, in the fifth embodiment described above, the plurality of first fin portions 271b provided on the first base portion 271a correspond to the first group, and the plurality of second fin portions 272b provided on the second base portion 272a correspond to the second group. Furthermore, in the fifth embodiment described above, the first heat sink portion 271D corresponds to the first part, and the second heat sink portion 272D corresponds to the second part. [Variation]

[0119] In the embodiments described above, a configuration in which the lengths of multiple fin sections in the Y direction are all the same was used as an example. However, the configuration is not limited to this, and for example, different lengths may be used to adjust for temperature variations. For example, the length in the Y direction of the first fin section of the first heat sink section or the first fin group may be made longer than the length of the second fin section of the second heat sink section or the second fin group, or vice versa.

[0120] Furthermore, in the fifth embodiment and its modified form, a configuration was applied to the first configuration example of the first embodiment in which the first heat sink portion is detachably attached to the second heat sink portion, but the configuration is not limited to this. For example, it may be applied to the second configuration example of the first embodiment, the first and second configuration examples of the second embodiment, and the first and second configuration examples of the fourth embodiment.

[0121] Furthermore, although the first embodiment and its modified examples described above include an example in which the first base portion 271a and the second base portion 272a are made of materials with different thermal conductivity, the configuration is not limited to this. The first base portion 271a and the second base portion 272a may be made of the same material, while the first fin portion 271b and the second fin portion 272b may be made of different materials. The same applies to the second configuration example of the first embodiment.

[0122] Furthermore, each of the above embodiments and its variations may be constructed by combining any two or more configurations, provided that they are combinable. For example, the configuration of the first embodiment can be combined with the configuration of the second embodiment, or the configuration of the first embodiment can be combined with the configuration of the fourth embodiment.

[0123] Furthermore, in the above embodiments and their modifications, the configuration in which the plate-shaped fin portions are arranged in the Z direction with their longitudinal direction facing the X direction was used as an example for explanation, but the configuration is not limited to this. For example, other configurations may be used, such as arranging them in the X direction with their longitudinal direction facing the Z direction. In addition, the position of the fan 28 and the position of the opening may be changed to appropriate positions depending on the arrangement. [Explanation of Symbols]

[0124] 1...Ultraviolet therapy device, 2...Therapy tool, 3...Main unit, 8...External power supply, 21...Light irradiation unit, 22...Grip unit, 23...Light emission window, 24...Housing, 25...LED board, 25a...LED light source, 25b...Board, 26...Light guide unit, 27,27A,27B,27C,27D...1st, 3rd, 5th, 7th, 9th heat sinks, 28...Fan, 29,29A,29B,29C...2nd, 4th, 6th, 8th heat sinks, 29Aa,272Aa,291a...Base unit, 31...Input unit, 32...Recording unit, 33...Display unit, 34...Power supply unit, 35...Control unit, 36...LED drive unit, 37... Connection wires, 37a, 37c... Power wires, 37b... Signal wires, 271a, 291a... First base section, 272a, 292a... Second base section, 29b, 272b... Fin section, 271b, 273b, 273Cb, 291b, 293Cb... First fin section, 29b, 272b, 272Cb, 293b... Second fin section, 273, 273B, 273C, 293, 293B, 293C... First fin group, 274, 274B, 274C, 294, 294B... Second fin group, 271, 271D, 291... First heat sink section, 272, 272D, 292... Second heat sink section

Claims

1. A housing having a light-emitting window that emits light including ultraviolet light, An LED substrate is provided within the housing facing the light emission window, and a plurality of LED light sources, each emitting light including ultraviolet light toward the light emission window, are mounted in a two-dimensional array on the substrate. A heat sink is attached to the LED board within the housing to dissipate heat from the LED board, The enclosure includes a blower located on the side of the heatsink opposite to the LED substrate, The heat sink has a heat sink base attached to the side of the LED substrate opposite to the mounting surface of the LED light source, and a plurality of fin portions provided on the side of the heat sink base opposite to the LED substrate side and extending from that side in the direction opposite to the LED substrate side. The plurality of fin portions comprises a first group, which is a group of some of the plurality of fin portions provided in the central part of the heat sink base, and a second group, which is a group of the remaining plurality of fin portions provided in the peripheral part, which is the outer part of the heat sink base outside the first group. An ultraviolet therapy device characterized in that the heat dissipation capacity of the first group is higher than that of the second group.

2. The ultraviolet therapy device according to claim 1, characterized in that the thermal conductivity of the first group is greater than the thermal conductivity of the second group.

3. The ultraviolet therapy device according to claim 2, characterized in that the first group is made of copper and the second group is made of aluminum.

4. The ultraviolet therapy device according to claim 2, characterized in that a portion of the heat sink base facing the first group is made of a material having the same thermal conductivity as the first group, and the other portion of the heat sink base facing the second group is made of a material having the same thermal conductivity as the second group.

5. The aforementioned heatsink is A gap is formed between each adjacent fin portion of the first group and the second group, which serves as a flow path for cooling air. The ultraviolet therapy device according to claim 1, characterized in that the total surface area per unit area of ​​the fin portion of the first group facing the central portion of the heat sink base is greater than the total surface area per unit area of ​​the fin portion of the second group facing the peripheral portion of the heat sink base.

6. The aforementioned heatsink is A gap is formed between each adjacent fin portion of the first group and the second group, which serves as a flow path for cooling air. The multiple fin portions constituting the first group and the second group have the same width in at least the direction of arrangement. The ultraviolet therapy device according to claim 1, characterized in that the density of the fin portion per unit area of ​​the central portion of the first group facing the central portion of the heat sink base is greater than the density of the fin portion per unit area of ​​the peripheral portion of the second group facing the peripheral portion of the heat sink base.

7. The aforementioned heatsink is A gap is formed between each adjacent fin portion of the first group and the second group, which serves as a flow path for cooling air. The ultraviolet therapy device according to claim 1, characterized in that the thickness of each fin portion constituting the first group is smaller than the thickness of each fin portion constituting the second group, and the spacing between each adjacent fin portion in the first group is smaller than the spacing between each adjacent fin portion in the second group.

8. The ultraviolet therapy device according to claim 1, characterized in that the total surface area of ​​the fin portions per unit area of ​​the opposing heat sink base is continuously and gradually increasing from the end to the center of the heat sink base.

9. The aforementioned heatsink is The ultraviolet therapy device according to claim 1, characterized in that the width in the arrangement direction of each fin portion constituting the first group is smaller than the width in the arrangement direction of each fin portion constituting the second group, and the number of fin portions per unit area of ​​the central portion of the first group facing the central portion of the heat sink base is greater than the number of fin portions per unit area of ​​the peripheral portion of the second group facing the peripheral portion of the heat sink base.

10. The ultraviolet therapy device according to claim 1, characterized in that the first portion of the heat sink, including the first group and the central portion of the heat sink base, and the second portion, including the second group and the peripheral portion of the heat sink base, are made of separate members, and the first portion is configured to be detachably attached to the second portion.

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