Ultraviolet treatment device

Abstract

To reduce the size and weight of an ultraviolet treatment device.SOLUTION: There is provided an ultrasonic treatment device for applying ultraviolet light to skin. The ultraviolet treatment device comprises a light guide plate, where the light guide plate includes a first end face, a second end face opposite to the first end face, an ultraviolet emission surface between the first end face and the second end face and intersecting the first end face and the second end face, and an opposite surface between the first end face and the second end face and opposite to the ultraviolet emission surface. The ultraviolet light propagates inside the light guide plate while reflecting between the ultraviolet emission surface and the opposite surface. The ultraviolet treatment device further includes an ultraviolet light source that causes ultraviolet light to be incident on the first end face of the light guide plate, and a transmission plate that faces the light guide plate and transmits the ultraviolet light emitted from the ultraviolet emission surface of the light guide plate. A light diffusion structure is provided on at least one of the ultraviolet emission surface side and the opposite surface side of the light guide plate.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present invention relates to an ultraviolet therapy device that irradiates ultraviolet rays onto a patient's skin. [Background technology]

[0002] Phototherapy involves the use of ultraviolet light in wavelengths such as UVA (wavelength 320nm-400nm) and UVB (wavelength 280nm-320nm). In UV therapy, ultraviolet light exposure suppresses the immune system, resulting in a therapeutic effect. For example, Patent Document 1 discloses an ultraviolet treatment device equipped with a plurality of LEDs that emit ultraviolet light for treating skin diseases. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Patent Publication No. 2021-122676 Summary of the Invention [Problem to be solved by the invention]

[0004] The ultraviolet treatment device disclosed in Patent Document 1 is suitable for irradiating ultraviolet rays onto a small area, ie, a spot, of an affected area. However, when irradiating hands, feet, arms, legs, trunk, etc. with ultraviolet light, the affected area may be larger than the area irradiated by the ultraviolet light emitted from the ultraviolet light therapy device. In this case, it is necessary to irradiate the ultraviolet light multiple times while changing the irradiation position. Even if the time per irradiation is short, changing the irradiation position takes time, so the total time required for treatment is long. Furthermore, if the irradiation position is changed frequently and frequently, a worker (doctor or nurse) will have to stay with the patient during treatment. Furthermore, since it is desirable to avoid overlapping of irradiation positions, skill is required to operate the treatment device, and the patient may be required to change their position frequently, which places a burden on the patient.

[0005] Therefore, an ultraviolet light therapy device that can irradiate ultraviolet light on a wide area of ​​the affected area at once is desirable. To irradiate a wide area with ultraviolet light, it is possible to provide multiple ultraviolet light sources or a large ultraviolet light source that emits light toward the affected area. However, providing multiple UV light sources or a large UV light source that emits UV light toward the affected area increases the size of the UV therapy device. Furthermore, in this case, irradiating a wide area with UV light requires a large distance between the UV light source and the affected area. Furthermore, a large cooling mechanism (e.g., a heat sink) is required to cool the UV light source. In particular, when using LED chips as UV light sources, strict temperature control is required because the temperature of the LED chip affects the emitted wavelength. When providing multiple LED chips that emit light toward the affected area, a large and heavy cooling mechanism would be required to dissipate the heat generated by the LED chips. A large and heavy cooling mechanism increases the thickness of the UV therapy device. Furthermore, to reduce the effect of variations in the emission wavelength of individual LED chips, a structure that increases the distance between the LED light-emitting surface and the affected area and evenly distributes UV light with varying wavelengths is preferable, but this also increases the thickness and further increases the size.

[0006] Therefore, the present invention provides an ultraviolet treatment device that can be made smaller and lighter. [Means for solving the problem]

[0007] One aspect of the present invention provides an ultraviolet therapy device for irradiating skin with ultraviolet light. The ultraviolet therapy device includes a light guide plate having a first end face, a second end face opposite the first end face, an ultraviolet light exit face between the first end face and the second end face and intersecting the first end face and the second end face, and an opposite face between the first end face and the second end face and opposite the ultraviolet light exit face, where ultraviolet light propagates through the light guide plate while being reflected by the ultraviolet light exit face and the opposite face, an ultraviolet light source that causes ultraviolet light to enter the first end face of the light guide plate, and a transmission plate facing the light guide plate and transmitting the ultraviolet light exiting from the ultraviolet light exit face of the light guide plate. A light diffusion structure is provided on at least one of the ultraviolet light exit face side and the opposite face side of the light guide plate. [Effects of the Invention]

[0008] In one embodiment of the present invention, an ultraviolet light source introduces ultraviolet light into a first end surface of a light guide plate. The ultraviolet light propagates within the light guide plate, reflecting off the ultraviolet light exit surface and the opposite surface, and being diffused by the light diffusion structure, before exiting from the ultraviolet light exit surface. The ultraviolet light exiting the ultraviolet light exit surface of the light guide plate is then released to the outside through the transmission plate and directed at the affected area of ​​the skin. By using a light guide plate and a light diffusion structure, ultraviolet light can be output from the ultraviolet light exit surface and thus the transmission plate with as uniform an intensity as possible, even if the area of ​​the ultraviolet light exit surface and thus the transmission plate is large, or even if a small ultraviolet light source is used. By using a small ultraviolet light source, the cooling mechanism for cooling the ultraviolet light source can also be small and lightweight. This allows for a smaller and lighter ultraviolet therapy device. [Brief explanation of the drawings]

[0009] [Figure 1] 1 is a cross-sectional view of an ultraviolet treatment device according to a first embodiment of the present invention. [Figure 2] FIG. 10 is a perspective view of an ultraviolet treatment device according to a second embodiment of the present invention. [Figure 3] FIG. 3 is a cross-sectional view taken along the line III-III in FIG. 2. [Figure 4]FIG. 10 is a cross-sectional view of an ultraviolet irradiation unit of an ultraviolet treatment device according to a second embodiment. [Figure 5] FIG. 2 is a perspective view of an ultraviolet irradiation unit. [Figure 6] FIG. 2 is a perspective view of a reflecting wall member of the ultraviolet irradiation unit. [Figure 7] FIG. 2 is a front view of an ultraviolet light source of the ultraviolet irradiation unit. [Figure 8] FIG. 10 is a rear view of an ultraviolet light source according to a modified example. [Figure 9] FIG. 2 is a perspective view of two ultraviolet light sources and a heat sink of the ultraviolet irradiation unit. [Figure 10] FIG. 5 is a partially enlarged view of FIG. [Figure 11] FIG. 1 is a partially enlarged plan view of the ultraviolet irradiation unit, showing the trajectory of ultraviolet light from one LED chip. [Figure 12] FIG. 10 is a cross-sectional view of an ultraviolet irradiation unit according to a modified example of the second embodiment. [Figure 13] FIG. 10 is a cross-sectional view of an ultraviolet irradiation unit according to another modified example of the second embodiment. [Figure 14] FIG. 10 is a cross-sectional view of an ultraviolet irradiation unit according to another modified example of the second embodiment. [Figure 15] FIG. 10 is a cross-sectional view of an ultraviolet irradiation unit according to another modified example of the second embodiment. [Figure 16] FIG. 10 is a cross-sectional view of an ultraviolet irradiation unit according to another modified example of the second embodiment. [Figure 17] FIG. 10 is a cross-sectional view of an ultraviolet irradiation unit according to another modified example of the second embodiment. [Figure 18] FIG. 10 is a cross-sectional view of an ultraviolet irradiation unit according to another modified example of the second embodiment. [Figure 19] FIG. 10 is a cross-sectional view of an ultraviolet irradiation unit according to another modified example of the second embodiment. DETAILED DESCRIPTION OF THE INVENTION

[0010] Various embodiments of the present invention will now be described with reference to the accompanying drawings, in which the drawings are not necessarily to scale and some features may be exaggerated or omitted.

[0011] The ultraviolet therapy device 1 according to the first embodiment of the present invention shown in Figure 1 includes two ultraviolet light sources 2, a light guide plate 5, a light transmitting plate 6, and a reflecting plate 8. The ultraviolet therapy device 1 irradiates ultraviolet light onto the skin of a human or other animal to promote the healing of skin diseases.

[0012] Each ultraviolet light source 2 may emit medium-wave ultraviolet (UVB) or long-wave ultraviolet (UVA). Medium-wave ultraviolet (wavelength 308 nm to 313 nm) is known to be effective in treating psoriasis, parapsoriasis, palmoplantar pustulosis, malignant lymphoma, mycosis fungoides, chronic lichenoides, vitiligo vulgaris, atopic dermatitis, alopecia areata, etc. Long-wave ultraviolet (wavelength 340 nm to 400 nm) is known to be effective in treating cutaneous T-cell lymphoma, mycosis fungoides, scleroderma, dyshidrotic eczema, etc. Each ultraviolet light source 2 has a substrate 3 and a plurality of LED (light emitting diode) chips 4 mounted on the substrate 3. The plurality of LED chips 4 are aligned in a direction perpendicular to the plane of the paper in Fig. 1. However, each ultraviolet light source 2 may have a plurality of other ultraviolet light source elements (for example, incandescent lamps or fluorescent lamps) instead of the plurality of LED chips 4.

[0013] The light guide plate 5 is a plate made of a transparent material such as transparent resin or glass, and has a first end face 5a, a second end face 5b, an ultraviolet light exit face 5c, and an opposite face 5d. The second end face 5b is located opposite the first end face 5a. The ultraviolet light exit face 5c and the opposite face 5d are located between the first end face 5a and the second end face 5b and intersect with the first end face 5a and the second end face 5b. The opposite face 5d is located opposite the ultraviolet light exit face 5c. In the figure, arrows without symbols schematically indicate the direction of travel of ultraviolet light. One ultraviolet light source 2 causes ultraviolet light to be incident on a first end face 5a of the light guide plate 5, and the other ultraviolet light source 2 causes ultraviolet light to be incident on a second end face 5b of the light guide plate 5. The ultraviolet light incident on the light guide plate 5 by the ultraviolet light source 2 propagates inside the light guide plate 5 while being reflected by the ultraviolet light exit surface 5c and the opposite surface 5d. In this embodiment, two ultraviolet light sources 2 are provided to cause ultraviolet light to enter the two end faces 5a and 5b, respectively, but one ultraviolet light source 2 may be omitted. In place of the omitted ultraviolet light source 2, a reflection wall that reflects ultraviolet light toward the light guide plate 5 may be provided.

[0014] The transmission plate 6 is a plate made of a transparent material such as transparent resin or glass, and faces the ultraviolet ray exit surface 5c of the light guide plate 5. The transmission plate 6 transmits the ultraviolet ray emitted from the ultraviolet ray exit surface 5c of the light guide plate 5. The ultraviolet ray output from the transmission plate 6 is irradiated onto the affected area such as the hands, feet, arms, legs, or trunk.

[0015] A light diffusion structure is provided on at least one of the ultraviolet emitting surface 5c side and the opposite surface 5d side of the light guide plate 5. For example, the ultraviolet emitting surface 5c may be a light diffusion surface, the opposite surface 5d may be a light diffusion surface, or both the ultraviolet emitting surface 5c and the opposite surface 5d may be light diffusion surfaces. In this embodiment, the opposite surface 5d is the light diffusion surface (light diffusion structure) 7. The light diffusion surface 7 may be formed by, for example, sandblasting, processing using a laser beam, or printing. Within the light guide plate 5, ultraviolet light propagates while being reflected by the ultraviolet light exit surface 5c and the opposite surface 5d and while being diffused by the light diffusion structure, and then exits from the ultraviolet light exit surface 5c.

[0016] The ultraviolet light emitted from the ultraviolet light emitting surface 5c of the light guide plate 5 is emitted to the outside through the transmission plate 6 and applied to the affected area of ​​the skin. By using the light guide plate 5 and a light diffusion structure (e.g., the light diffusion surface 7), even if the area of ​​the ultraviolet light emitting surface 5c and therefore the transmission plate 6 is large, or even if a small ultraviolet light source 2 is used, ultraviolet light can be output from the ultraviolet light emitting surface 5c and therefore the transmission plate 6 with as uniform an intensity as possible to a wide area of ​​the affected area. Because ultraviolet light can be irradiated to a wide area of ​​the affected area at once, there is no need for a worker (doctor or nurse) to stay with the patient during treatment, and the burden on the patient is reduced. By using a small ultraviolet light source 2, the cooling mechanism for cooling the ultraviolet light source can also be small and lightweight. Therefore, the ultraviolet therapy device 1 can be made smaller and lighter.

[0017] The surface of the reflector 8 has high light reflectivity. The reflector 8 is made of, for example, metal. However, the reflector 8 may be made of resin, and a reflective film with high light reflectivity may be formed on the surface of the reflector 8. The reflector 8 faces the ultraviolet light exit surface 5c of the light guide plate 5, and reflects ultraviolet light leaking from the light guide plate 5 toward the light guide plate 5. This reduces the loss of ultraviolet light emitted from the ultraviolet light source 2. The reflector 8 may be spaced apart from the light guide plate 5. However, it is preferable that the reflector 8 be in contact with the light guide plate 5 in order to minimize attenuation loss of ultraviolet light.

[0018] As described above, in this embodiment, the opposite surface 5d of the light guide plate 5 is the light diffusing surface 7. This is preferable to the case where the ultraviolet ray exit surface 5c is the light diffusing surface. This is because even if the gap between the transmission plate 6 and the light guide plate 5 is small, the distance between the light diffusing surface 7 and the transmission plate 6 is large, so that the ultraviolet ray diffused by the light diffusing surface 7 is output from the transmission plate 6 with as uniform an intensity as possible. However, the ultraviolet ray exit surface 5c may be a light diffusing surface, or a light diffusing plate (not shown) may be interposed between the ultraviolet ray exit surface 5c and the light transmitting plate 6. A light diffusing plate (not shown) may be interposed between the opposite surface 5d and the reflecting plate 8. The reflector 8 may be a light diffusion plate serving as a light diffusion structure. In this case, the ultraviolet rays are dispersed with as uniform an intensity as possible over a wide area of ​​the ultraviolet emitting surface 5c and therefore the transmission plate 6, so the light guide plate 5 does not need to be provided with the light diffusion surface 7. However, if the light guide plate 5 is provided with the light diffusion surface 7 and the reflector 8 is also a light diffusion plate, the ultraviolet rays are further diffused within the light guide plate 5, and the ultraviolet rays are dispersed with even greater intensity over the ultraviolet emitting surface 5c and therefore the wide area of ​​the transmission plate 6.

[0019] 2 and 3 show an ultraviolet therapy device 1A according to a second embodiment of the present invention. The ultraviolet therapy device 1A irradiates ultraviolet rays onto the skin of a human or other animal to promote the healing of skin diseases. The ultraviolet therapy device 1A has an ultraviolet irradiation unit 1B, a housing 10 that surrounds the ultraviolet irradiation unit 1B, and a plurality of legs 11 provided on the lower part of the housing 10. The ultraviolet therapy device 1A further has a plurality of fans 12 arranged on two side walls of the housing 10.

[0020] The housing 10 is a box having a substantially rectangular parallelepiped shape. The housing 10 is assembled from a plurality of thin plates made of a rigid material (e.g., metal). The ultraviolet irradiation unit 1B is fixed inside the housing 10. An opening is formed in the upper wall of the housing 10, and the transmission plate 6 of the ultraviolet irradiation unit 1B is exposed through the opening. The ultraviolet rays output from the transmission plate 6 are irradiated onto the affected area such as the hands, feet, arms, legs, or trunk. The patient may move the affected area away from the permeable plate 6, or may place the affected area in contact with the permeable plate 6. The permeable plate 6 and the housing 10 are designed to have sufficiently high rigidity so as to withstand the weight of the patient. Furthermore, the permeable plate 6 and the housing 10 are made of a material that does not immediately react with cleaning agents (e.g., alcohol) so that they will not deteriorate even when cleaned with the cleaning agent.

[0021] The legs 11 are intended to be placed on the floor. Each leg 11 has a threaded portion 11a, which is screwed into a threaded hole formed in the bottom wall of the housing 10. By adjusting the length of the leg 11, the housing 10 and therefore the ultraviolet irradiation unit 1B can be tilted to match the position or angle of the affected area.

[0022] The fan 12 blows air to the ultraviolet light sources 2 of the ultraviolet irradiation unit 1B to cool the ultraviolet light sources 2.

[0023] 3, a power supply unit 13 is disposed inside the housing 10. The power supply unit 13 has a power source 13a and a control unit 13b. The control unit 13b receives power supplied from the power source 13a and controls the light emission of the ultraviolet light source 2 of the ultraviolet irradiation unit 1B and the driving of the fan 12.

[0024] 4 and 5 show the ultraviolet irradiation unit 1B. Fig. 4 is a diagram in which the housing 10, legs 11, and fan 12 are removed from Fig. 3, and is a cross-sectional view taken along line IV-IV in Fig. 5. The ultraviolet irradiation unit 1B has four ultraviolet light sources 2, four light guide plates 15, a single transmission plate 6, and a single reflective wall member 18. However, the transmission plate 6 is not shown in Fig. 5.

[0025] As shown in Figure 6, the reflecting wall member 18 has a bottom wall 19, two side walls 18a, two end walls 18b, a single central side wall 18c, a single central wall 18d, and two end covering walls 18e. The surface of the reflecting wall member 18 has a high light reflectance. The reflecting wall member 18 is formed of, for example, metal. However, the reflecting wall member 18 may be formed of resin, and a reflective film with a high light reflectance may be formed on the surface of the reflecting wall member 18. The bottom wall (reflector) 19 corresponds to the reflector 8 in the first embodiment. The bottom wall 19 has a rectangular shape. The side wall 18a, the end wall 18b, the central side wall 18c, and the central wall 18d are arranged on one side of the bottom wall 19 and are perpendicular to the bottom wall 19. The side wall 18a, the end wall 18b, the central side wall 18c, and the central wall 18d are reflective walls that reflect ultraviolet light.

[0026] The side walls (third reflecting walls) 18a are arranged parallel to each other and are connected to both side edges of the bottom wall 19 without any gaps. The end walls (second reflecting walls) 18b are arranged parallel to each other and are respectively arranged near both end edges of the bottom wall 19. However, the end walls 18b are spaced apart from the bottom wall 19. Each end wall 18b is connected to both side walls 18a without any gaps.

[0027] The central side wall (fourth reflecting wall) 18c is disposed between the two side walls 18a and is disposed parallel to the side walls 18a. The central side wall 18c is connected to the bottom wall 19 and both end walls 18b without any gaps. The central wall (first reflecting wall) 18d is disposed between the two end walls 18b and is disposed parallel to the end walls 18b. The central wall 18d is connected to the bottom wall 19 and both side walls 18a without any gaps. Viewed from another perspective, both side walls 18a and central side wall 18c are perpendicular to central wall 18d and both end walls 18b.

[0028] Each of the side walls 18a and the central side wall 18c has an extension 18f extending in the longitudinal direction at both ends. Each end covering wall 18e is disposed parallel to and spaced apart from the bottom wall 19, and is seamlessly connected to the extensions 18f of both side walls 18a, the extensions 18f of the central side wall 18c, and the end wall 18b. Because each end covering wall 18e is spaced apart from the bottom wall 19, the extensions 18f of the side walls 18a, the extensions 18f of the central side wall 18c, the end covering walls 18e, and the bottom wall 19 define a rectangular opening 18g.

[0029] As shown in FIGS. 4 and 5, each light guide plate 15 is a rectangular plate made of a transparent material such as transparent resin or glass. The four light guide plates 15 are arranged on the same plane to form a rectangle. Each light guide plate 15 is disposed within a rectangular region defined by side walls 18a, end walls 18b, central side wall 18c, and central wall 18d. That is, each light guide plate 15 is surrounded by side walls 18a, end walls 18b, central side wall 18c, and central wall 18d. In other words, the reflective wall member 18 has four regions in which the four light guide plates 15 are disposed.

[0030] Each light guide plate 15 has a first end face 15a, a second end face 15b, a third end face 15c, a fourth end face 15d, an ultraviolet ray exit face 15e, and an opposite face 15f. First end face 15a, second end face 15b, third end face 15c, and fourth end face 15d define a rectangle. Second end face 15b is opposite first end face 15a. Third end face 15c and fourth end face 15d are located between first end face 15a and second end face 15b and perpendicular to first end face 15a and second end face 15b. Fourth end face 15d is opposite third end face 15c. The ultraviolet ray exit surface 15e is located between the first end face 15a and the second end face 15b and intersects with the first end face 15a and the second end face 15b. The ultraviolet ray exit surface 15e is also located between the third end face 15c and the fourth end face 15d and intersects with the third end face 15c and the fourth end face 15d. The opposite surface 15f is also located between the first end surface 15a and the second end surface 15b and intersects with the first end surface 15a and the second end surface 15b. The opposite surface 15f is also located between the third end surface 15c and the fourth end surface 15d and intersects with the third end surface 15c and the fourth end surface 15d. The opposite surface 15f is located opposite the ultraviolet light exit surface 15e.

[0031] The first end face 15a faces the opening 18g (see FIG. 6) of the reflecting wall member 18. The first end face 15a is located near the end wall 18b of the reflecting wall member 18 but is not covered by the end wall 18b. The second end face 15b faces the central wall 18d of the reflecting wall member 18 and is covered by the central wall 18d. The third end face 15c faces the side wall 18a of the reflecting wall member 18 and is covered by the side wall 18a. The fourth end face 15d faces the central side wall 18c of the reflecting wall member 18 and is covered by the central side wall 18c.

[0032] As in the first embodiment, each ultraviolet light source 2 may emit medium-wave ultraviolet light (UVB) or long-wave ultraviolet light (UVA). 5, in the second embodiment, two ultraviolet light sources 2 are arranged along each end wall 18b of the reflecting wall member 18. Therefore, each ultraviolet light source 2 is arranged along the first end surface 15a of one light guide plate 15. Each ultraviolet light source 2 has a substrate 3 and a plurality of LED chips 4 mounted on the substrate 3. The plurality of LED chips (ultraviolet light source elements) 4 are lined up along the first end surface 15a of the light guide plate 15 (along the direction perpendicular to the paper surface of FIG. 4). However, each ultraviolet light source 2 may have a plurality of other ultraviolet light source elements (for example, incandescent lamps or fluorescent lamps) instead of the plurality of LED chips 4.

[0033] In the figure, arrows without symbols indicate the direction of travel of ultraviolet light. The ultraviolet light source elements (e.g., the LED chips 4) of each ultraviolet light source 2 cause ultraviolet light to be incident on the first end face 15a of one light guide plate 15. The ultraviolet light incident on the light guide plate 15 by the ultraviolet light source 2 propagates inside the light guide plate 15 while being reflected by the ultraviolet light exit surface 15e and the opposite surface 15f.

[0034] The transmission plate 6 is provided in common to the four light guide plates 15. The transmission plate 6 is a plate made of a transparent material such as transparent resin or glass, and faces the ultraviolet ray exit surfaces 15e of the four light guide plates 15, covering these ultraviolet ray exit surfaces 15e. The transmission plate 6 is parallel to the ultraviolet ray exit surfaces 15e of the four light guide plates 15. The transmission plate 6 transmits ultraviolet rays emitted from the ultraviolet ray exit surfaces 15e of each light guide plate 15.

[0035] A light diffusion structure is provided on at least one of the ultraviolet emitting surface 15e side and the opposite surface 15f side of each light guide plate 15. For example, the ultraviolet emitting surface 15e may be a light diffusion surface, the opposite surface 15f may be a light diffusion surface, or both the ultraviolet emitting surface 15e and the opposite surface 15f may be light diffusion surfaces. In this embodiment, the opposite surface 15f is the light diffusion surface (light diffusion structure) 17. The light diffusion surface 17 may be formed by, for example, sandblasting, processing using a laser beam, or printing. Within the light guide plate 15, ultraviolet light propagates while being reflected by the ultraviolet light exit surface 15e and the opposite surface 15f and while being diffused by the light diffusion structure, and then exits from the ultraviolet light exit surface 15e.

[0036] The ultraviolet light emitted from the ultraviolet light emitting surface 15e of the light guide plate 15 is emitted to the outside through the transmission plate 6 and applied to the affected area of ​​the skin. By using the light guide plate 15 and a light diffusion structure (e.g., the light diffusion surface 17), ultraviolet light can be output from the ultraviolet light emitting surface 15e and thus the transmission plate 6 with as uniform an intensity as possible, even if the area of ​​the ultraviolet light emitting surface 15e and thus the transmission plate 6 is large or even if a small ultraviolet light source 2 is used. By using a small ultraviolet light source 2, the cooling mechanism for cooling the ultraviolet light source (e.g., a heat sink, described later) can also be small and lightweight. Therefore, the ultraviolet therapy device 1A and the ultraviolet irradiation unit 1B can be made smaller and lighter.

[0037] The bottom wall 19 of the reflective wall member 18 is a reflecting plate that faces the ultraviolet ray exit surface 15e of the light guide plate 15 and reflects ultraviolet rays leaking from the light guide plate 15 toward the light guide plate 15. This makes it possible to reduce loss of ultraviolet rays emitted from the ultraviolet light source 2. The bottom wall 19 may be spaced apart from the light guide plate 15. However, it is preferable that the bottom wall 19 be in contact with the light guide plate 15 in order to minimize attenuation loss of ultraviolet light.

[0038] As described above, in this embodiment, the opposite surface 15f of the light guide plate 15 is the light diffusing surface 17. This is preferable to the case where the ultraviolet ray exit surface 15e is the light diffusing surface. This is because even if the gap between the transmission plate 6 and the light guide plate 15 is small, the distance between the light diffusing surface 17 and the transmission plate 6 is large, so that the ultraviolet ray diffused by the light diffusing surface 17 is output from the transmission plate 6 with as uniform an intensity as possible. However, the ultraviolet ray exit surface 15e may be a light diffusing surface, or a light diffusing plate (not shown) may be interposed between the ultraviolet ray exit surface 15e and the transmission plate 6. A light diffusing plate (not shown) may be interposed between the opposite surface 15f and the bottom wall 19 of the reflecting wall member 18. The bottom wall 19 of the reflecting wall member 18 may be a light diffusion plate serving as a light diffusion structure. In this case, the ultraviolet rays are dispersed with as uniform intensity as possible over a wide area of ​​the ultraviolet ray exit surface 15e and therefore the transmission plate 6, so the light guide plate 15 does not need to be provided with the light diffusion surface 17. However, if the light guide plate 15 is provided with the light diffusion surface 17 and the bottom wall 19 of the reflecting wall member 18 is a light diffusion plate, the ultraviolet rays are further diffused within the light guide plate 15, and the ultraviolet rays are dispersed with even greater uniform intensity over the ultraviolet ray exit surface 15e and therefore the wide area of ​​the transmission plate 6.

[0039] Because ultraviolet light propagates within the light guide plate 15 while being reflected by the ultraviolet light exit surface 15e and the opposite surface 15f and being diffused by the light diffusion structure, the number of ultraviolet light source elements (e.g., LED chips 4) in each ultraviolet light source 2 can be small even if the area of ​​the ultraviolet light exit surface 15e and therefore the area of ​​the transmission plate 6 are large. This allows the ultraviolet therapy device 1A to be made smaller and lighter. The wavelength of UV light emitted from a UV light source element can change depending on temperature. Furthermore, due to manufacturing variations, the peak wavelength of UV light emitted from individual UV light source elements can vary. For example, an LED chip designed to emit UV light with a peak wavelength of 308 nm may contain an LED chip that emits UV light with a peak wavelength of 306 nm or an LED chip that emits UV light with a peak wavelength of 310 nm. Even slight differences in wavelength can result in significant differences in therapeutic efficacy. Meanwhile, with regard to UVB in particular, even slight differences in wavelength can affect the likelihood of causing erythema on the skin, making it undesirable to expose the skin to UV light with wavelengths that are prone to causing erythema for extended periods of time. However, if at least one of the ultraviolet light source elements of each ultraviolet light source 2 emits ultraviolet light of a desired wavelength that contributes to treatment, the ultraviolet light propagates within the light guide plate 15 while being reflected by the ultraviolet light emitting surface 15e and the opposite surface 15f and while being diffused by the light diffusion structure, and thus the ultraviolet light of the desired wavelength is dispersed as evenly as possible over a wide area of ​​the ultraviolet light emitting surface 15e and therefore the transmission plate 6. Therefore, ultraviolet light of the desired wavelength is output from the ultraviolet light emitting surface 15e and therefore the transmission plate 6. Furthermore, ultraviolet light of undesirable wavelengths is also dispersed as evenly as possible over a wide area of ​​the ultraviolet light emitting surface 15e and therefore the transmission plate 6, preventing light of wavelengths that are likely to cause erythema from locally irradiating the skin.

[0040] As mentioned above, each ultraviolet light source element may be an incandescent bulb or a fluorescent lamp, but the LED chip 4 is smaller, has a longer lifespan, consumes less power, and is more shock-resistant than an incandescent bulb or a fluorescent lamp.

[0041] 7, each ultraviolet light source 2 has a rectangular substrate 3 and a plurality of LED chips 4 mounted on a surface 3a of the substrate 3. The LED chips 4 are arranged in a straight line along the longitudinal direction of the substrate 3. The substrate 3 has through holes 3c formed in the four corners.

[0042] A connector 20 is mounted on the surface 3a of the substrate 3. The connector 20 is electrically connected to a control section 13b of the power supply unit 13 (see FIG. 3). Furthermore, wiring 21 for supplying power from the connector 20 to the LED chips 4 is formed on the surface 3a of the substrate 3. In this embodiment, 15 LED chips 4 are provided on each substrate 3, and the 15 LED chips 4 are classified into three LED groups 4a, 4b, and 4c as shown in FIG. 7. Each of the LED groups 4a, 4b, and 4c has five LED chips 4. The three LED groups 4a, 4b, and 4c are connected in parallel by patterning the wiring 21. However, the number and arrangement of the LED chips 4 are not limited to those in the illustrated embodiment. In this embodiment, neither the connector 20 nor the wiring 21 is formed on the rear surface 3b of the substrate 3. However, as in a modified example shown in Fig. 8, the wiring 21 may be formed on the rear surface 3b of the substrate 3. In this modified example, the connector 20 and the LED chip 4 are mounted on the front surface 3a of the substrate 3 and are electrically connected to the wiring 21 via, for example, a conductor disposed in a through hole.

[0043] As shown in FIG. 9 , one heat sink 22 is attached to two ultraviolet light sources 2. The heat sink 22, which is a heat dissipation member, is made of a metal material and has a flat plate portion and numerous fins extending from the flat plate portion. The flat plate portion is in contact with the rear surface 3b of the substrate 3. The substrate 3 is fixed to the flat plate portion of the heat sink 22 by screws 23 passing through through holes 3c of the substrate 3. In FIG. 9 , the wiring 21 formed on the front surface 3a of the substrate 3 is not shown. In this embodiment, neither the connector 20 nor the wiring 21 is formed on the rear surface 3b of the substrate 3, so the flat plate portion of the heat sink 22 is in surface contact with the rear surface 3b of the substrate 3 over a wide area. In the modified example shown in FIG. 8 , since the wiring 21 is formed on the rear surface 3b of the substrate 3, it is preferable that at least the flat plate portion of the heat sink 22 be formed from a non-conductive material, such as a ceramic material. As shown in FIG. 3, the fan 12 blows air toward the heat sink 22 to cool the substrate 3 and the LED chip 4.

[0044] As shown in FIGS. 3 and 4, the substrate 3 of each heat sink 22 faces the first end face 15a of the light guide plate 15, and the LED chip 4 directs ultraviolet light to be incident on the first end face 15a. Therefore, each heat sink 22 is disposed on the side of the light guide plate 15, rather than in the thickness direction of the light guide plate 15. Therefore, the LED chip 4 can be cooled while the thickness of the ultraviolet irradiation unit 1B is reduced.

[0045] In this embodiment, the central wall 18d of the reflective wall member 18 faces the second end face 15b of each light guide plate 15 and reflects ultraviolet light propagating within the light guide plate 15. The central wall 18d reflects ultraviolet light leaking from the second end face 15b of each light guide plate 15 toward the light guide plate 15, thereby reducing loss of ultraviolet light. Although the second end face 15b of each light guide plate 15 may be spaced apart from the central wall 18d, attenuation loss of ultraviolet light can be minimized if the second end face 15b is in contact with the central wall 18d.

[0046] As shown in FIG. 4 , the central wall 18d covers the second end surface 15b of each light guide plate 15 and protrudes further toward the transmission plate 6 than each light guide plate 15, with the upper edge of the central wall 18d in FIG. 4 contacting the transmission plate 6. Because the central wall 18d covers the second end surface 15b of each light guide plate 15, loss of ultraviolet light can be further reduced. Furthermore, because the central wall 18d protrudes further toward the transmission plate 6 than each light guide plate 15 and the upper edge of the central wall 18d contacts the transmission plate 6, the distance between the transmission plate 6 and each light guide plate 15 can be maintained appropriately. In other words, the central wall 18d functions as a spacer that maintains the distance between the transmission plate 6 and each light guide plate 15 appropriately. The distance between the transmission plate 6 and the light guide plate 15 is determined, for example, so that ultraviolet light can be output from the transmission plate 6 with as uniform an intensity as possible. To minimize loss of ultraviolet light, it is preferable that the upper edge of the central wall 18d contact the transmission plate 6 without any gaps.

[0047] Each end wall 18b of the reflective wall member 18 faces the central wall 18d and reflects ultraviolet light emitted from the light guide plate 15. Each end wall 18b reflects ultraviolet light leaking from the light guide plate 15 toward the central wall 18d, thereby further reducing loss of ultraviolet light. Each end wall 18b is spaced apart from the bottom wall 19 and the light guide plate 15, and functions as a spacer that maintains an appropriate distance between the transmission plate 6 and each light guide plate 15. To minimize loss of ultraviolet light, it is preferable that the upper edge of each end wall 18b be in contact with the transmission plate 6 without any gap.

[0048] 5, the side wall 18a of the reflective wall member 18 faces the third end face 15c of the light guide plate 15 and covers the third end face 15c, and the central side wall 18c of the reflective wall member 18 faces the fourth end face 15d of the light guide plate 15 and covers the fourth end face 15d. In this way, each light guide plate 15 is surrounded by the central wall 18d, the end wall 18b, the side wall 18a, and the central side wall 18c. These reflective walls (the central wall 18d, the end wall 18b, the side wall 18a, and the central side wall 18c) reflect ultraviolet light that leaks from the light guide plate 15, thereby reducing the loss of ultraviolet light. Furthermore, the side walls 18a and the central side wall 18c protrude further toward the transmission plate 6 than the light guide plates 15 and come into contact with the transmission plate 6, thereby maintaining an appropriate distance between the transmission plate 6 and each light guide plate 15. That is, the side walls 18a and the central side wall 18c also function as spacers that maintain an appropriate distance between the transmission plate 6 and each light guide plate 15. To minimize loss of ultraviolet light, it is preferable that the upper edges of the side walls 18a and the central side wall 18c come into contact with the transmission plate 6 without any gaps.

[0049] In this embodiment, the two side walls 18a and the central side wall 18c are connected to the central wall 18d and the two end walls 18b, and the central wall 18d, the end walls 18b, the side walls 18a, and the central side wall 18c constitute a single reflecting wall member 18. Therefore, the central wall 18d, the end walls 18b, the side walls 18a, and the central side wall 18c are easy to transport, and the ultraviolet therapy device 1A is easy to assemble.

[0050] FIG. 10 shows an enlarged view of a portion of FIG. 4. The edge of the bottom wall 19 of the reflective wall member 18 is positioned close to the surface 3a of the substrate 3 of the UV light source 2 and may be in contact with the surface 3a. The extensions 18f of the side walls 18a and central side wall 18c (see FIG. 6) of the reflective wall member 18 are also positioned close to the surface 3a of the substrate 3 of the UV light source 2 and may be in contact with the surface 3a. The edge covering walls 18e of the reflective wall member 18 are also positioned close to the surface 3a of the substrate 3 of the UV light source 2 and may be in contact with the surface 3a. In this manner, the LED chip 4 is disposed inside the opening 18g defined by the extensions 18f of the side walls 18a, the extensions 18f of the central side wall 18c, the edge covering walls 18e, and the bottom wall 19. Therefore, the LED chip 4 is isolated from the outside world, and UV light emitted from the LED chip 4 enters the first end surface 15a of the light guide plate 15 with minimal loss. Moreover, the LED chip 4 can be placed as close as possible to the first end face 15a of the light guide plate 15.

[0051] In this embodiment, the ultraviolet irradiation unit 1B includes multiple light guide plates 15 and multiple ultraviolet light sources 2 corresponding to the multiple light guide plates 15. The two light guide plates 15 are arranged such that their second end faces 15b are close to each other, their first end faces 15a are far from each other, and their ultraviolet light emitting surfaces 15e face the same direction. Therefore, the ultraviolet light emitting surfaces 15e of the two light guide plates 15 are aligned, allowing ultraviolet light to be irradiated onto a wide area of ​​the affected area. Inside each light guide plate 15, ultraviolet light emitted from the ultraviolet light source 2 is reflected by the ultraviolet light emitting surface 15e and the opposite surface 15f, and then diffused by the light diffusion structure while propagating, before being emitted from the ultraviolet light emitting surface 15e. Therefore, ultraviolet light can be output from the ultraviolet light emitting surface 15e and, ultimately, the transmission plate 6, with as uniform an intensity as possible to the wide area of ​​the affected area. Because ultraviolet light can be irradiated onto a wide area of ​​the affected area at once, there is no need for an operator to constantly attend to the patient during treatment, reducing the burden on the patient. Each ultraviolet light source 2 emits ultraviolet light to the first end face 15a of one light guide plate 15. The central wall 18d is interposed between the second end faces 15b of the two light guide plates 15 and faces the two second end faces 15b to reflect ultraviolet light leaking from the second end faces 15b toward the light guide plates 15, thereby reducing loss of ultraviolet light. Fig. 11 is a partially enlarged plan view of the ultraviolet irradiation unit 1B, and schematically shows the trajectory of ultraviolet light from one LED chip 4. As shown in Fig. 11, the side walls 18a, end walls 18b, central side wall 18c, and central wall 18d of the reflective wall member 18 define spaces arranged in a grid pattern, and a light guide plate 15 is disposed in each space. The wavelength of the UV light emitted from the LED chip 4 may vary depending on temperature. Furthermore, due to manufacturing variations, the peak wavelength of the UV light emitted from each LED chip 4 may differ. However, if at least one of the LED chips 4 in the UV light source 2 emits UV light of the desired wavelength contributing to treatment, the UV light emitted from that LED chip 4 propagates while being reflected by the UV light emitting surface 15e and the opposite surface 15f and diffused by the light diffusion structure. The UV light is also reflected by the side walls 18a, end walls 18b, central sidewall 18c, and central wall 18d of the reflecting wall member 18. Therefore, the UV light of the desired wavelength emitted from any one LED chip 4 is distributed over the wide area defined by the side walls 18a, end walls 18b, central sidewall 18c, and central wall 18d of the reflecting wall member 18. This allows the UV light of the desired wavelength to be dispersed as evenly as possible over the UV light emitting surface 15e and the wide area of ​​the transmission plate 6. Therefore, ultraviolet light of the desired wavelength is output from the ultraviolet light emitting surface 15e and thus from a wide area of ​​the transmission plate 6. In addition, ultraviolet light of undesired wavelengths is also dispersed as evenly as possible over the ultraviolet light emitting surface 15e and thus the wide area of ​​the transmission plate 6.

[0052] Preferably, the control unit 13b (see FIG. 3) individually controls the emission of light from the four ultraviolet light sources 2. In this case, by activating one ultraviolet light source 2, ultraviolet light is output from the ultraviolet light emission surface 15e of the light guide plate 15 corresponding to that ultraviolet light source 2. Alternatively, by activating multiple ultraviolet light sources 2, ultraviolet light is output from the ultraviolet light emission surfaces 15e of the multiple light guide plates 15 corresponding to those ultraviolet light sources 2. Therefore, the area from which ultraviolet light is output can be changed depending on the area of ​​the affected area or the condition of the affected area. Individual control of the light emission of the ultraviolet light sources 2 may involve causing the LED chip 4 of one ultraviolet light source 2 to emit light at a high emission intensity and the LED chip 4 of another ultraviolet light source 2 to emit light at a low emission intensity. In this case, ultraviolet light is output at a high emission intensity from the ultraviolet emission surface 15e of the light guide plate 15 corresponding to the LED chip 4 that emits light at a high emission intensity, and ultraviolet light is output at a low emission intensity from the ultraviolet emission surface 15e of the light guide plate 15 corresponding to the LED chip 4 that emits light at a low emission intensity. Therefore, the distribution of the output intensity of ultraviolet light can be changed depending on the condition of the affected area. Individual control of the light emission of the ultraviolet light sources 2 may involve causing the LED chip 4 of one ultraviolet light source 2 to emit light for a long time and the LED chip 4 of another ultraviolet light source 2 to emit light for a short time. In this case, ultraviolet light is output for a long time from the ultraviolet emission surface 15e of the light guide plate 15 corresponding to the LED chip 4 that emitted light for a long time, and ultraviolet light is output for a short time from the ultraviolet emission surface 15e of the light guide plate 15 corresponding to the LED chip 4 that emitted light for a short time. Therefore, the distribution of the ultraviolet light output time can be changed depending on the condition of the affected area.

[0053] 12 to 17 each show an ultraviolet irradiation unit according to a modified example of the second embodiment. Each of the ultraviolet irradiation units 1C and 1D is disposed inside the housing 10 in place of the ultraviolet irradiation unit 1B (see FIGS. 2 and 3). 12 to 17 are cross-sectional views similar to those in FIG. 4, but show the ultraviolet irradiation units on a larger scale than those in FIG. 4.

[0054] In the ultraviolet irradiation unit 1C shown in FIGS. 12 to 14, a light diffusion surface (light diffusion structure) 17 is provided on the opposite surface 15f of the light guide plate 15. The light diffusion surface 17 has a plurality of recesses 17a formed on the opposite surface 15f. The recesses 17a can be formed by processing using a laser beam. In reality, the depth and area of ​​the recesses 17a, as well as the spacing between the recesses 17a, are small, and the recesses 17a cannot be seen with the naked eye. For ease of understanding, the size of the recesses 17a and the spacing between the recesses 17a are shown enlarged in FIGS. 12 to 14. Each light guide plate 15 has a central region Ra and a peripheral region Rb. As shown in Fig. 5, the central region Ra is a region that is a certain distance or more away from the ultraviolet light source 2, the end wall 18b, the central wall 18d, the side wall 18a, and the central side wall 18c. The peripheral region Rb is a region that is a certain distance or less away from the ultraviolet light source 2, the end wall 18b, the central wall 18d, the side wall 18a, and the central side wall 18c, i.e., a region other than the central region Ra.

[0055] 12, the intervals between the recesses 17a become smaller with increasing distance from the ultraviolet light source 2, the end wall 18b, the central wall 18d, the side wall 18a, and the central side wall 18c. For example, the intervals between the recesses 17a in the central region Ra are smaller than the intervals between the recesses 17a in the peripheral region Rb.

[0056] 13, the area of ​​the recesses 17a increases with increasing distance from the ultraviolet light source 2, the end wall 18b, the central wall 18d, the side wall 18a, and the central side wall 18c. For example, the area of ​​the recesses 17a in the central region Ra is larger than the area of ​​the recesses 17a in the peripheral region Rb.

[0057] 14, the distance between the recesses 17a decreases and the area of ​​the recesses 17a increases with increasing distance from the ultraviolet light source 2, the end wall 18b, the central wall 18d, the side wall 18a, and the central side wall 18c. For example, the distance between the recesses 17a in the central region Ra is smaller than the distance between the recesses 17a in the peripheral region Rb. The area of ​​the recesses 17a in the central region Ra is larger than the area of ​​the recesses 17a in the peripheral region Rb.

[0058] 12 to 14, the intensity of ultraviolet light output from the ultraviolet light output surface 15e is improved at positions far from the ultraviolet light source 2, the end wall 18b, the central wall 18d, the side wall 18a, and the central side wall 18c. Therefore, ultraviolet light can be output from the ultraviolet light output surface 15e and ultimately from the transmission plate 6 with as uniform an intensity as possible.

[0059] In the ultraviolet irradiation unit 1D shown in FIGS. 15 to 17, a light diffusion surface (light diffusion structure) 17 is provided on the opposite surface 15f of the light guide plate 15. The light diffusion surface 17 has a plurality of protrusions 17b formed on the opposite surface 15f. The protrusions 17b can be formed by printing (e.g., screen printing). In reality, the height and area of ​​the protrusions 17b, as well as the spacing between the protrusions 17b, are small and therefore cannot be seen with the naked eye. For ease of understanding, the size and spacing between the protrusions 17b are enlarged in FIGS. 15 to 17. Furthermore, to make the protrusions 17b more noticeable, the opposite surface 15f of the light guide plate 15 is depicted as being separated from the bottom wall 19 of the reflecting wall member 18 in FIGS. 15 to 17. However, to reduce attenuation loss of ultraviolet light, it is preferable that the opposite surface 15f be in contact with the bottom wall 19.

[0060] 15, the spacing between the protrusions 17b decreases with increasing distance from the ultraviolet light source 2, the end wall 18b, the central wall 18d, the side wall 18a, and the central side wall 18c. For example, the spacing between the protrusions 17b in the central region Ra is smaller than the spacing between the protrusions 17b in the peripheral region Rb.

[0061] 16, the area of ​​the convex portion 17b increases with increasing distance from the ultraviolet light source 2, the end wall 18b, the central wall 18d, the side wall 18a, and the central side wall 18c. For example, the area of ​​the convex portion 17b in the central region Ra is larger than the area of ​​the convex portion 17b in the peripheral region Rb.

[0062] 17, the distance between the adjacent protrusions 17b decreases and the area of ​​the adjacent protrusions 17b increases with increasing distance from the ultraviolet light source 2, the end wall 18b, the central wall 18d, the side wall 18a, and the central side wall 18c. For example, the distance between the adjacent protrusions 17b in the central region Ra is smaller than the distance between the adjacent protrusions 17b in the peripheral region Rb. The area of ​​the adjacent protrusions 17b in the central region Ra is larger than the area of ​​the adjacent protrusions 17b in the peripheral region Rb.

[0063] 15 to 17, the intensity of ultraviolet light output from the ultraviolet light output surface 15e is improved at positions far from the ultraviolet light source 2, the end wall 18b, the central wall 18d, the side wall 18a, and the central side wall 18c. Therefore, ultraviolet light can be output from the ultraviolet light output surface 15e and ultimately from the transmission plate 6 with as uniform an intensity as possible.

[0064] 18 and 19 each show an ultraviolet irradiation unit 1E according to a modification of the second embodiment. Each of the ultraviolet irradiation units 1E is disposed inside the housing 10 in place of the ultraviolet irradiation unit 1B (see FIGS. 2 and 3). FIGS. 18 and 19 are cross-sectional views similar to FIG. 4. 18 and 19, a light diffusing surface (light diffusing structure) 17 is provided on an ultraviolet ray exit surface 15e of a light guide plate 15. The light diffusing surface 17 may be formed by, for example, sandblasting, processing using a laser beam, or printing. The ultraviolet ray exit surface 15e is perpendicular to the first end surface 15a and the other end surfaces 15b, 15c, and 15d.

[0065] 18, the opposite surface 15f of the light guide plate 15 and the reflector 19 are inclined so as to approach the ultraviolet light emission surface 15e with increasing distance from the ultraviolet light source 2. The light guide plate 15 is wedge-shaped. 19, the opposite surface 15f of the light guide plate 15 and the reflector 19 are curved so as to approach the ultraviolet light emission surface 15e with increasing distance from the ultraviolet light source 2. The light guide plate 15 is substantially wedge-shaped.

[0066] 18 and 19, the intensity of ultraviolet light output from the ultraviolet light output surface 15e is improved at a position far from the ultraviolet light source 2. Therefore, ultraviolet light can be output from the ultraviolet light output surface 15e and ultimately from the transmission plate 6 with as uniform an intensity as possible.

[0067] Other variations Although the present invention has been shown and described with reference to preferred embodiments thereof, it will be understood by those skilled in the art that changes may be made in form and detail without departing from the scope of the invention as set forth in the appended claims. Such changes, modifications and alterations are intended to be included within the scope of the invention. For example, the ultraviolet irradiation unit 1B according to the second embodiment has four light guide plates 15, but the number of light guide plates 15 may be two, or three or more.

[0068] The ultraviolet treatment device 1A according to the second embodiment is assumed to be placed on the floor, but the ultraviolet irradiation unit 1B may be incorporated into a treatment device that can be held and operated by hand. In the second embodiment, the reflector 19 facing the light guide plate 15 is the bottom wall of the reflector wall member 18, but the reflector 19 facing the light guide plate 15 may be separated from the reflector wall member 18. However, in the second embodiment, the reflector 19 is the bottom wall of the reflector wall member 18 and is integrally connected to the side wall 18a, the central side wall 18c, and the central wall 18d, so that loss of ultraviolet light can be minimized.

[0069] Aspects of the invention are also described in the following numbered clauses. Article 1. An ultraviolet therapy device that irradiates the skin with ultraviolet rays, a light guide plate having a first end face, a second end face opposite to the first end face, an ultraviolet light emission face between the first end face and the second end face and intersecting the first end face and the second end face, and an opposite face between the first end face and the second end face and opposite to the ultraviolet light emission face, wherein ultraviolet light propagates inside the light guide plate while being reflected by the ultraviolet light emission face and the opposite face; an ultraviolet light source that causes ultraviolet light to be incident on the first end surface of the light guide plate; a transmission plate facing the light guide plate and transmitting ultraviolet light emitted from the ultraviolet light exit surface of the light guide plate, A light diffusion structure is provided on at least one of the ultraviolet ray exit surface side and the opposite surface side of the light guide plate. An ultraviolet treatment device characterized by:

[0070] Clause 2. The ultraviolet light source has a plurality of ultraviolet light source elements, and the plurality of ultraviolet light source elements cause ultraviolet light to be incident on the first end surface of the light guide plate. 2. An ultraviolet treatment device according to claim 1, characterized in that Because the ultraviolet light propagates through the light guide plate while being reflected by the ultraviolet light exit surface and the opposite surface and being diffused by the light diffusion structure, the number of ultraviolet light source elements in the ultraviolet light source can be small even if the area of ​​the ultraviolet light exit surface and therefore the area of ​​the transmission plate is large, which allows for a smaller and lighter ultraviolet therapy device. The wavelength of ultraviolet light emitted from an ultraviolet light source element can vary depending on temperature. Furthermore, due to manufacturing variations, the peak wavelength of ultraviolet light emitted from each ultraviolet light source element may differ. However, if at least one of the ultraviolet light source elements of the ultraviolet light source emits ultraviolet light of the desired wavelength contributing to treatment, the ultraviolet light propagates within the light guide plate while being reflected by the ultraviolet light exit surface and the opposite surface and diffused by the light diffusion structure, thereby dispersing the ultraviolet light of the desired wavelength as evenly as possible over the ultraviolet light exit surface and the wide area of ​​the transmission plate. Therefore, ultraviolet light of the desired wavelength is output from the ultraviolet light exit surface and the wide area of ​​the transmission plate.

[0071] Clause 3. The ultraviolet light source has a plurality of LED chips as a plurality of ultraviolet light source elements. 3. An ultraviolet treatment device according to claim 2, characterized in that Compared to incandescent and fluorescent lamps, LED chips are smaller, have a longer lifespan, consume less power, and are more shock-resistant.

[0072] Clause 4. The ultraviolet light source has a substrate on which the plurality of LED chips are mounted, the substrate facing the first end surface of the light guide plate, The ultraviolet treatment device further includes a heat sink in contact with the rear surface of the substrate. 4. An ultraviolet treatment device according to claim 3, characterized in that In this case, the heat sink is arranged on the side of the light guide plate, not in the thickness direction of the light guide plate, which allows the LED chip to be cooled while reducing the thickness of the ultraviolet therapy device.

[0073] Clause 5. The light guide plate further includes a reflector on the opposite side of the light guide plate from the ultraviolet ray exit surface, which reflects ultraviolet rays toward the light guide plate. 5. An ultraviolet treatment device according to any one of clauses 1 to 4, characterized in that The reflector reflects ultraviolet light leaking from the light guide plate to the side opposite to the ultraviolet light exit surface toward the light guide plate, thereby reducing loss of ultraviolet light.

[0074] Clause 6. The reflector has the light diffusion structure 6. An ultraviolet treatment device according to clause 5, characterized in that In this case, the ultraviolet light is further diffused within the light guide plate, and the ultraviolet light is dispersed with as uniform an intensity as possible over a wide area of ​​the ultraviolet light exit surface and thus the light transmitting plate.

[0075] Clause 7. The optical element further includes a first reflecting wall that faces the second end surface of the light guide plate and reflects ultraviolet light propagating within the light guide plate. 7. An ultraviolet treatment device according to any one of clauses 1 to 6, characterized in that The first reflecting wall reflects ultraviolet light leaking from the second end face of the light guide plate toward the light guide plate, thereby reducing loss of ultraviolet light.

[0076] Clause 8. The first reflecting wall covers the second end face of the light guide plate, protrudes from the light guide plate toward the transmission plate, and contacts the transmission plate. 8. An ultraviolet treatment device according to claim 7, characterized in that The first reflecting wall covers the second end face of the light guide plate, thereby further reducing the loss of ultraviolet light. Furthermore, the first reflecting wall protrudes further toward the transmitting plate than the light guide plate and contacts the transmitting plate, thereby maintaining an appropriate distance between the transmitting plate and the light guide plate. In other words, the first reflecting wall functions as a spacer that maintains an appropriate distance between the transmitting plate and the light guide plate. The distance between the transmitting plate and the light guide plate is determined, for example, so that ultraviolet light can be output from the transmitting plate with as uniform an intensity as possible.

[0077] Clause 9. The light guide plate further includes a second reflecting wall that faces the first reflecting wall and reflects ultraviolet light emitted from the light guide plate. 9. An ultraviolet treatment device according to clause 7 or 8, characterized in that The second reflecting wall reflects ultraviolet light leaking from the light guide plate toward the first reflecting wall, thereby further reducing loss of ultraviolet light.

[0078] Clause 10. The light guide plate has a third end surface and a fourth end surface that are located between the first end surface and the second end surface and intersect with the first end surface and the second end surface, The ultraviolet treatment device further includes a third reflecting wall and a fourth reflecting wall intersecting the first reflecting wall and the second reflecting wall, the third reflecting wall faces the third end surface of the light guide plate and covers the third end surface, The fourth reflecting wall faces the fourth end surface of the light guide plate and covers the fourth end surface. 10. An ultraviolet treatment device according to claim 9, characterized in that The light guide plate is surrounded by a first reflecting wall, a second reflecting wall, a third reflecting wall, and a fourth reflecting wall, which reflect ultraviolet light that leaks from the light guide plate, thereby reducing the loss of ultraviolet light.

[0079] Clause 11. The third reflecting wall and the fourth reflecting wall are provided at their ends with extensions extending in the longitudinal direction; The ultraviolet treatment device is an end covering wall connected to the extension of the third reflecting wall, the extension of the fourth reflecting wall, and the second reflecting wall; an opening defined by the extension of the third reflector wall, the extension of the fourth reflector wall, and the edge cover wall; An ultraviolet light source element of the ultraviolet light source is disposed inside the opening. 11. An ultraviolet treatment device according to clause 10, characterized in that In this case, the ultraviolet light source element is isolated from the outside, and ultraviolet light emitted from the ultraviolet light source element is incident on the first end face of the light guide plate with minimal loss. Also, the ultraviolet light source element can be located as close as possible to the first end face of the light guide plate.

[0080] Clause 12. The third reflecting wall and the fourth reflecting wall are connected to the first reflecting wall and the second reflecting wall; The first reflecting wall, the second reflecting wall, the third reflecting wall, and the fourth reflecting wall constitute one member. 12. An ultraviolet treatment device according to clause 10 or 11, characterized in that Since the first reflecting wall, the second reflecting wall, the third reflecting wall and the fourth reflecting wall form a single member, the first reflecting wall, the second reflecting wall, the third reflecting wall and the fourth reflecting wall are easy to transport and the ultraviolet treatment device is easy to assemble.

[0081] Clause 13. A light emitting device comprising a plurality of the light guide plates and a plurality of the ultraviolet light sources respectively corresponding to the plurality of light guide plates; the two light guide plates are arranged such that the second end faces are close to each other, the first end faces are spaced apart from each other, and the ultraviolet light exit surfaces face the same direction; Each ultraviolet light source emits ultraviolet light to the first end surface of one light guide plate; The first reflecting wall is interposed between the second end surfaces of the two light guide plates and faces the two second end surfaces. 13. An ultraviolet treatment device according to any one of clauses 7 to 12, characterized in that In this case, the two light guide plates are arranged so that their second end faces are close to each other, their first end faces are far from each other, and their ultraviolet ray emitting surfaces face the same direction. Therefore, the ultraviolet ray emitting surfaces of the two light guide plates are aligned, allowing ultraviolet rays to be irradiated onto a wide area of ​​affected tissue. Inside each light guide plate, ultraviolet rays emitted from the ultraviolet light source are reflected by the ultraviolet ray emitting surface and the opposite surface, and are diffused by the light diffusion structure while propagating, and then emitted from the ultraviolet ray emitting surface. Therefore, ultraviolet rays can be output from the ultraviolet ray emitting surface and, ultimately, the transparent plate, with as uniform an intensity as possible to the wide area of ​​affected tissue. The first reflecting wall reflects ultraviolet rays leaking from the second end face of each light guide plate back toward the original light guide plate, thereby reducing ultraviolet ray loss.

[0082] Clause 14. The device further includes a control unit that individually controls the light emission of the plurality of ultraviolet light sources. 14. An ultraviolet treatment device according to claim 13, characterized in that In this case, by activating one ultraviolet light source, ultraviolet light is output from the ultraviolet light output surface of the light guide plate corresponding to that ultraviolet light source. By activating multiple ultraviolet light sources, ultraviolet light is output from the ultraviolet light output surfaces of multiple light guide plates corresponding to those ultraviolet light sources. Therefore, the area from which ultraviolet light is output can be changed depending on the area of ​​the affected area.

[0083] Clause 15. The light diffusion structure is provided on the opposite surface of the light guide plate; the light diffusion structure has a plurality of recesses formed on the opposite surface; The distance between the recesses decreases as the distance from the ultraviolet light source and the first reflecting wall increases. 15. An ultraviolet treatment device according to any one of clauses 7 to 14, characterized in that In this case, the intensity of the ultraviolet light output from the ultraviolet light output surface is improved at a position far from the ultraviolet light source and the first reflecting wall, and therefore the ultraviolet light can be output from the ultraviolet light output surface and, ultimately, the transmission plate with as uniform an intensity as possible.

[0084] Clause 16. The light diffusion structure is provided on the opposite surface of the light guide plate; the light diffusion structure has a plurality of recesses formed on the opposite surface; The area of ​​the recess increases as the distance from the ultraviolet light source and the first reflecting wall increases. 15. An ultraviolet treatment device according to any one of clauses 7 to 14, characterized in that In this case, the intensity of the ultraviolet light output from the ultraviolet light output surface is improved at a position far from the ultraviolet light source and the first reflecting wall, and therefore the ultraviolet light can be output from the ultraviolet light output surface and, ultimately, the transmission plate with as uniform an intensity as possible.

[0085] Clause 17. The light diffusion structure is provided on the opposite surface of the light guide plate; the light diffusion structure has a plurality of recesses formed on the opposite surface; As the distance from the ultraviolet light source and the first reflecting wall increases, the intervals between the recesses decrease and the areas of the recesses increase. 15. An ultraviolet treatment device according to any one of clauses 7 to 14, characterized in that In this case, the intensity of the ultraviolet light output from the ultraviolet light output surface is improved at a position far from the ultraviolet light source and the first reflecting wall, and therefore the ultraviolet light can be output from the ultraviolet light output surface and, ultimately, the transmission plate with as uniform an intensity as possible.

[0086] Clause 18. The light diffusion structure is provided on the opposite surface of the light guide plate; the light diffusion structure has a plurality of protrusions formed on the opposite surface, The distance between the protrusions decreases as the distance from the ultraviolet light source and the first reflecting wall increases. 15. An ultraviolet treatment device according to any one of clauses 7 to 14, characterized in that In this case, the intensity of the ultraviolet light output from the ultraviolet light output surface is improved at a position far from the ultraviolet light source and the first reflecting wall, and therefore the ultraviolet light can be output from the ultraviolet light output surface and, ultimately, the transmission plate with as uniform an intensity as possible.

[0087] Clause 19. The light diffusion structure is provided on the opposite surface of the light guide plate; the light diffusion structure has a plurality of protrusions formed on the opposite surface, The area of ​​the convex portion increases with increasing distance from the ultraviolet light source and the first reflecting wall. 15. An ultraviolet treatment device according to any one of clauses 7 to 14, characterized in that In this case, the intensity of the ultraviolet light output from the ultraviolet light output surface is improved at a position far from the ultraviolet light source and the first reflecting wall, and therefore the ultraviolet light can be output from the ultraviolet light output surface and, ultimately, the transmission plate with as uniform an intensity as possible.

[0088] Clause 20. The light diffusion structure is provided on the opposite surface of the light guide plate; the light diffusion structure has a plurality of protrusions formed on the opposite surface, As the distance from the ultraviolet light source and the first reflecting wall increases, the intervals between the convex portions decrease and the areas of the convex portions increase. 15. An ultraviolet treatment device according to any one of clauses 7 to 14, characterized in that In this case, the intensity of the ultraviolet light output from the ultraviolet light output surface is improved at a position far from the ultraviolet light source and the first reflecting wall, and therefore the ultraviolet light can be output from the ultraviolet light output surface and, ultimately, the transmission plate with as uniform an intensity as possible.

[0089] Clause 21. The light diffusion structure is provided on the ultraviolet ray exit surface of the light guide plate, The opposite surface of the light guide plate and the reflector are inclined or curved so as to approach the ultraviolet light exit surface as they move away from the ultraviolet light source. 6. An ultraviolet treatment device according to clause 5, characterized in that In this case, the intensity of the ultraviolet light output from the ultraviolet light output surface is improved at a position far from the ultraviolet light source, and therefore the ultraviolet light can be output from the ultraviolet light output surface and ultimately the transmission plate with as uniform an intensity as possible. [Explanation of symbols]

[0090] 1, 1A... ultraviolet treatment device, 1B, 1C, 1D, 1E... ultraviolet irradiation unit, 2... ultraviolet light source, 3... substrate, 3a... front surface, 3b... rear surface, 4... LED chip (ultraviolet light source element), 5... light guide plate, 5a... first end face, 5b... second end face, 5c... ultraviolet light exit surface, 5d... opposite surface, 6... transmitting plate, 8... reflecting plate, 7... light diffusion surface (light diffusion structure), 13b... control unit, 15... light guide plate, 15a... first end face, 15b... second end face, 15c... third end face, 15d... 4 end surface, 15e...ultraviolet light exit surface, 15f...opposite surface, 18...reflecting wall member, 18a...side wall (third reflecting wall), 18b...end wall (second reflecting wall), 18c...central side wall (fourth reflecting wall), 18d...central wall (first reflecting wall), 18e...end covering wall, 18f...extension, 18g...opening, 19...bottom wall (reflector), 17...light diffusion surface (light diffusion structure), 17a...recess, 17b...protrusion, 22...heat sink, Ra...central region of light guide plate, Rb...peripheral region of light guide plate

Claims

1. An ultraviolet treatment device that irradiates ultraviolet rays onto the skin, a light guide plate having a first end face, a second end face opposite to the first end face, an ultraviolet light emission face between the first end face and the second end face and intersecting the first end face and the second end face, and an opposite face between the first end face and the second end face and opposite to the ultraviolet light emission face, wherein ultraviolet light propagates inside the light guide plate while being reflected by the ultraviolet light emission face and the opposite face; an ultraviolet light source that causes ultraviolet light to be incident on the first end surface of the light guide plate; a transmission plate facing the light guide plate and transmitting ultraviolet light emitted from the ultraviolet light exit surface of the light guide plate, A light diffusion structure is provided on at least one of the ultraviolet ray exit surface side and the opposite surface side of the light guide plate. An ultraviolet treatment device characterized by:

2. The ultraviolet light source has a plurality of ultraviolet light source elements, and the plurality of ultraviolet light source elements cause ultraviolet light to be incident on the first end surface of the light guide plate.

2. The ultraviolet treatment device according to claim 1.

3. The ultraviolet light source has a plurality of LED chips as a plurality of ultraviolet light source elements.

3. The ultraviolet treatment device according to claim 2.

4. the ultraviolet light source has a substrate on which the plurality of LED chips are mounted, the substrate facing the first end surface of the light guide plate; The ultraviolet treatment device further includes a heat sink in contact with the rear surface of the substrate.

4. The ultraviolet treatment device according to claim 3.

5. The light guide plate further includes a reflector on the opposite side of the light guide plate from the ultraviolet light exit surface, the reflector reflecting ultraviolet light toward the light guide plate.

5. An ultraviolet treatment device according to claim 1.

6. The reflector has the light diffusion structure.

6. The ultraviolet treatment device according to claim 5.

7. a first reflecting wall facing the second end surface of the light guide plate and reflecting ultraviolet light propagating within the light guide plate; 5. An ultraviolet treatment device according to claim 1.

8. The first reflecting wall covers the second end surface of the light guide plate, protrudes further toward the light transmitting plate than the light guide plate, and is in contact with the light transmitting plate.

8. The ultraviolet treatment device according to claim 7.

9. a second reflecting wall facing the first reflecting wall and reflecting ultraviolet light emitted from the light guide plate; 8. The ultraviolet treatment device according to claim 7.

10. the light guide plate has a third end face and a fourth end face that are located between the first end face and the second end face and intersect with the first end face and the second end face, The ultraviolet treatment device further includes a third reflecting wall and a fourth reflecting wall intersecting the first reflecting wall and the second reflecting wall, the third reflecting wall faces the third end surface of the light guide plate and covers the third end surface, The fourth reflecting wall faces the fourth end surface of the light guide plate and covers the fourth end surface.

10. The ultraviolet treatment device according to claim 9.

11. an extension portion extending in a longitudinal direction is formed at an end portion of the third reflecting wall and the fourth reflecting wall; The ultraviolet treatment device is an end covering wall connected to the extension of the third reflecting wall, the extension of the fourth reflecting wall, and the second reflecting wall; an opening defined by the extension of the third reflector wall, the extension of the fourth reflector wall, and the edge cover wall; An ultraviolet light source element of the ultraviolet light source is disposed inside the opening.

11. The ultraviolet treatment device according to claim 10.

12. the third reflecting wall and the fourth reflecting wall are connected to the first reflecting wall and the second reflecting wall, The first reflecting wall, the second reflecting wall, the third reflecting wall, and the fourth reflecting wall constitute one member.

11. The ultraviolet treatment device according to claim 10.

13. a plurality of the light guide plates and a plurality of the ultraviolet light sources respectively corresponding to the plurality of light guide plates; the two light guide plates are arranged such that the second end surfaces are close to each other, the first end surfaces are spaced apart from each other, and the ultraviolet light exit surfaces face the same direction; Each ultraviolet light source emits ultraviolet light onto the first end surface of one light guide plate; The first reflecting wall is interposed between the second end surfaces of the two light guide plates and faces the two second end surfaces.

8. The ultraviolet treatment device according to claim 7.

14. The ultraviolet ray source may further include a control unit that controls the light emission of the plurality of ultraviolet ray light sources individually.

14. The ultraviolet treatment device according to claim 13.

15. the light diffusion structure is provided on the opposite surface of the light guide plate, the light diffusion structure has a plurality of recesses formed on the opposite surface; The distance between the recesses decreases as the distance from the ultraviolet light source and the first reflecting wall increases.

8. The ultraviolet treatment device according to claim 7.

16. the light diffusion structure is provided on the opposite surface of the light guide plate, the light diffusion structure has a plurality of recesses formed on the opposite surface; The area of ​​the recess increases as the distance from the ultraviolet light source and the first reflecting wall increases.

8. The ultraviolet treatment device according to claim 7.

17. the light diffusion structure is provided on the opposite surface of the light guide plate, the light diffusion structure has a plurality of recesses formed on the opposite surface; As the distance from the ultraviolet light source and the first reflecting wall increases, the distance between the recesses decreases and the area of ​​the recesses increases.

8. The ultraviolet treatment device according to claim 7.

18. the light diffusion structure is provided on the opposite surface of the light guide plate, the light diffusion structure has a plurality of protrusions formed on the opposite surface, The distance between the protrusions decreases as the distance from the ultraviolet light source and the first reflecting wall increases.

8. The ultraviolet treatment device according to claim 7.

19. the light diffusion structure is provided on the opposite surface of the light guide plate, the light diffusion structure has a plurality of protrusions formed on the opposite surface, The area of ​​the convex portion increases with increasing distance from the ultraviolet light source and the first reflecting wall.

8. The ultraviolet treatment device according to claim 7.

20. the light diffusion structure is provided on the opposite surface of the light guide plate, the light diffusion structure has a plurality of protrusions formed on the opposite surface, As the distance from the ultraviolet light source and the first reflecting wall increases, the intervals between the convex portions decrease and the areas of the convex portions increase.

8. The ultraviolet treatment device according to claim 7.

21. the light diffusion structure is provided on the ultraviolet light exit surface of the light guide plate, The opposite surface of the light guide plate and the reflector are inclined or curved so as to approach the ultraviolet light exit surface as they move away from the ultraviolet light source.

6. The ultraviolet treatment device according to claim 5.

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