Ultraviolet irradiation device

Abstract

To provide an ultraviolet light irradiation device which prevents water from entering the inside of the device even when the device is installed in a place where water is expected to be used or where moisture is present. [Solution] The ultraviolet light irradiation device comprises a light source that emits ultraviolet light with a main peak wavelength of 240 nm or less, a housing that houses the light source, an opening provided in a part of the housing, a window member made of a material that is transparent to ultraviolet light, and a sealing member installed on the surface of the window member, wherein the window member closes the opening while abutting against the inner wall of the housing via the sealing member, and the sealing member abuts against the surface of the window member outside the opening.

Description

[Technical Field]

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

[0002] The present applicant has previously proposed an ultraviolet light irradiation device equipped with an excimer lamp that irradiates ultraviolet light in a wavelength range that contributes to sterilization and virus inactivation while reducing the intensity of light in a wavelength range that is feared to have adverse effects on the human body (see, for example, Patent Document 1). [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Publication No. 2023-066627 Summary of the Invention [Problem to be solved by the invention]

[0004] Sterilization and virus inactivation processes may be desired not only in general indoor spaces such as conference rooms, waiting rooms, and hallways, but also in wet areas such as washrooms, kitchens, toilets, and bathrooms, and in humid locations such as the inside of air conditioners (hereinafter collectively referred to as "water-containing locations"). However, conventional ultraviolet light irradiation devices were not designed for use in such locations where water splashes or water droplets may adhere. Therefore, if a conventional ultraviolet light irradiation device is installed directly in a water-containing location for the purpose of sterilization or virus inactivation, there is a risk that water will infiltrate the device due to water splashes or water droplets adhering to the device.

[0005] If water gets into the device, it can cause a short circuit in the power supply system or rust, which can lead to a decrease in the illuminance of the UV light or cause lighting problems. In addition, UV light irradiating the water inside the housing can generate highly reactive OH radicals inside the housing, which can deteriorate the housing walls and the modules inside the housing.

[0006] In view of the above problems, the present invention aims to provide an ultraviolet light irradiation device that prevents water from entering the device even when the device is installed in a location where water is expected to be used or where moisture is present. [Means for solving the problem]

[0007] The ultraviolet light irradiation device according to the present invention comprises: a light source that emits ultraviolet light having a main peak wavelength of 240 nm or less; a housing that houses the light source; an opening provided in a portion of the housing; a window member made of a material that is transparent to ultraviolet light; a seal member disposed on a surface of the window member, the window member closes the opening while being in contact with the inner wall of the housing via the seal member; The sealing member is characterized in that it abuts against a surface of the window member outside the opening.

[0008] The ultraviolet light is emitted to the outside of the device through the window member. The window member is arranged so as to close an opening provided in the housing, but a tiny gap is inevitably formed between the housing and the window member. Therefore, in the case of conventional devices, if the device is installed in a location where water is expected to be used or where moisture is present (a water-existing location), water may enter the device through this gap.

[0009] In contrast, according to the above configuration, a seal member is installed on the surface of the window member that closes the opening, at a position outside the opening, and the window member and the inner wall of the housing abut against each other via the seal member. This makes it possible to close a gap between the window member and the housing with the seal member. As a result, even if the device is installed in a location where water is present, it is possible to prevent water from entering the device.

[0010] In this specification, the term "main peak wavelength" refers to the wavelength that exhibits the highest light intensity in the entire wavelength range.

[0011] In this specification, "exhibiting transparency" means that when light is incident on an object at an incident angle of 0°, the intensity of the light that passes through the object (transmitted light) is 50% or more of the intensity of the incident light.

[0012] The sealing member is preferably made of an elastically deformable material, from the viewpoint of improving adhesion between the window member and the inner wall of the housing, and examples of such materials include various rubber materials such as ethylene propylene, nitrile, fluorine, silicone, and urethane, and various resin materials such as fluororesins typified by PTFE, polyamide, polyethylene, and polyacetal.

[0013] The sealing member may be made of a breathable material. A part of the ultraviolet light emitted from the light source may be absorbed by oxygen contained in the air inside the housing, generating a small amount of ozone.

[0014] When the light source is turned on, the light source and power supply generate heat, causing the air inside the housing to expand. In conventional structures, an unavoidable gap exists between the housing and the window member, and gas inside the housing is exhausted to the outside through this gap. Therefore, even if a small amount of ozone is generated inside the housing, the gas containing this ozone is exhausted to the outside air, making it difficult for the ozone to remain inside the housing.

[0015] On the other hand, in the case of the ultraviolet light irradiation device according to the present invention, as described above, the gap is closed by a sealing member. Therefore, if a small amount of ozone is generated inside the housing, the ozone tends to remain in the inner space of the housing. Since the amount of ozone generated increases depending on the lighting time of the light source, it is thought that a longer lighting time may deteriorate the components housed inside the housing.

[0016] According to the above configuration, since the sealing member exhibits breathability, it is possible to discharge gas inside the housing to the outside air even while closing the opening with the sealing member, which makes it difficult for ozone to remain inside the housing even when the lamp is turned on for a long time.

[0017] Furthermore, since the sealing member exhibits breathability, it is expected that the effect of making it easier to maintain the closed state of the gap will also be achieved.

[0018] When a sealing member is provided, the interior space of the housing becomes a substantially sealed space. Therefore, when the temperature in the space rises, the air in the space expands, and conversely, when the temperature drops, the air in the space contracts. Repeated expansion and contraction over time with use of the ultraviolet light irradiation device can cause deformation due to changes in air pressure in the weakest parts of the housing, potentially forming tiny gaps. When such tiny gaps are formed, the possibility of water entering the housing from the outside through these gaps cannot be ruled out.

[0019] In contrast, by using a breathable sealing member, even if the temperature of the internal space of the housing rises and the air in the internal space expands, this air can be exhausted to the outside of the housing through the sealing member. Conversely, even if the temperature of the internal space of the housing drops and the air in the internal space contracts, the air outside the housing can be allowed to flow into the internal space of the housing through the sealing member. In other words, regardless of the usage state of the ultraviolet light irradiation device, the air pressure inside the internal space of the housing can be kept approximately the same as the air pressure in the external space of the housing, thereby suppressing the deterioration of the airtightness of the internal space of the housing that occurs over time.

[0020] As a material for the breathable sealing member, various resin materials such as fluororesins typified by PTFE, polyamide, polyethylene, polyacetal, etc., which have been made porous, can be used. A porous resin is a resin material having pores on the order of μm, and has, for example, a fibrous structure or a mesh structure. Typically, porous PTFE can be used as the material for the sealing member.

[0021] The window member may include a bandpass filter that blocks transmission of light in the wavelength range of 240 nm to 280 nm.

[0022] According to the above configuration, even if the wavelength range of 240 nm to 280 nm is included in the tail portion of the spectrum of ultraviolet light emitted from the light source, the intensity of this wavelength range of 240 nm to 280 nm is significantly reduced compared to the intensity of the peak wavelength when the light is emitted from the device. Light with wavelengths less than 240 nm is known to be less harmful to the human body than light in the wavelength range of 240 nm to 280 nm. Therefore, even if a portion of the ultraviolet light extracted from the device through the window member is irradiated onto a human, the effects on the human body are suppressed.

[0023] However, from the viewpoint of further suppressing the effects on the human body, the main peak wavelength is preferably 235 nm or less, and more preferably 230 nm or less. Furthermore, the shorter the wavelength, the more easily the light is absorbed by oxygen in the air, and the shorter the distance it propagates through the air. Therefore, in consideration of applications for sterilization and virus inactivation, the peak wavelength is preferably 190 nm or more, and more preferably 200 nm or more.

[0024] A light source that emits ultraviolet light in this wavelength range can be an excimer lamp that includes a light-emitting tube filled with a mixed gas containing Kr and Cl, or a mixed gas containing Kr and Br. As another example, the light source can be an LED or LD made of a nitride semiconductor such as AlGaN or AlN, or an oxide semiconductor such as MgZnO.

[0025] As another example, a phosphor may be placed on the tube wall of the arc tube, and the light source may emit excimer light with a peak wavelength of less than 200 nm. In this case, the arc tube is filled with a light-emitting gas such as Xe or ArF, and the phosphor may be LaPO4:Pr, K2YF5:Pr, LaF3:Nd, or the like. In this configuration, the excimer light generated inside the arc tube is wavelength-converted by the phosphor and extracted as ultraviolet light with a peak wavelength of 200 nm to 230 nm.

[0026] The sealing member may be frame-shaped, which can improve adhesion between the window member and the inner wall of the housing via the sealing member.

[0027] When the light source is an excimer lamp including an arc tube, the device may include a lamp holder for supporting the arc tube. In this case, the sealing member may have a first sealing member installed on a first surface of the window member and a second sealing member installed on a second surface of the window member opposite to the first surface, the first sealing member abutting on an inner wall of the housing, and the second sealing member abutting on an outer wall of the lamp holder. [Effects of the Invention]

[0028] According to the ultraviolet light irradiation device of the present invention, even when the device is installed in a location where water is expected to be used or where moisture is present, it is possible to prevent water from entering the inside of the device. [Brief explanation of the drawings]

[0029] [Figure 1] 1 is a perspective view schematically illustrating the structure of an embodiment of an ultraviolet light irradiation device. [Figure 2] 2 is a perspective view schematically showing a state in which a first component 3 and a second component 4 are separated from the ultraviolet light irradiation device 1 shown in FIG. [Figure 3] 2. FIG. 3 is a perspective view schematically showing the ultraviolet light irradiation device 1 shown in FIG. 1 in a state where a first component 3 and a second component 4 are separated, and is shown from a different viewing direction than FIG. [Figure 4]FIG. 4 is an exploded perspective view of the members housed inside the first component 3, with the second component 4 omitted from FIG. 3. [Figure 5] FIG. 1 is a cross-sectional perspective view of only the first component 3, cut along a predetermined plane. [Figure 6] 6 is a cross-sectional perspective view of the first component 3 with the window member 5 and the sealing members 12 and 13 housed inside, cut at the same position as in FIG. 5. FIG. [Figure 7] FIG. 7 is an enlarged view of an area α1 in FIG. [Figure 8] 3 is a perspective view showing the first component 3 from FIG. 2, but viewed from a different direction. [Figure 9] FIG. 9 is a perspective view of FIG. 8 in which the buffer member 32 is omitted. [Figure 10] 8 is a perspective view showing the lamp holder 31 and the buffer member 32 separated from the second part 4. FIG. [Figure 11] 2 is a schematic cross-sectional view of the ultraviolet light irradiation device 1 shown in FIG. 1 taken along the XZ plane at a location where an electrode 35 and the outer wall of the arc tube 30 are in contact with each other. DETAILED DESCRIPTION OF THE INVENTION

[0030] Embodiments of an ultraviolet light irradiation device according to the present invention will be described below with reference to the accompanying drawings. Note that the drawings are all schematic illustrations, and the dimensional ratios and number of elements in the drawings do not necessarily correspond to the actual dimensional ratios and number of elements.

[0031] Fig. 1 is a perspective view schematically showing the structure of one embodiment of an ultraviolet light irradiation device. As shown in Fig. 1, the ultraviolet light irradiation device 1 includes a housing 2. In the ultraviolet light irradiation device 1 of this embodiment, the housing 2 has a first component 3 and a second component 4, which are fitted together to form an accommodation space inside. Fig. 2 is a perspective view schematically showing a state in which the first component 3 and the second component 4 are separated from the state shown in Fig. 1.

[0032] 1 and 2, a window member 5 is provided in a part of the housing 2, more specifically, in a part of the first component 3. As shown in Fig. 2, an arc tube 30 constituting a light source is housed inside the housing 2, more specifically, on the side of the second component 4. The arc tube 30 is supported by a lamp holder 31.

[0033] As will be described later with reference to Figure 10, the outer wall of the arc tube 30 is in contact with a pair of electrodes 35, 36. A light-emitting gas is sealed in the arc tube 30, and when a voltage is applied between the pair of electrodes 35, 36, the light-emitting gas discharges within the arc tube 30, generating plasma, and the constituent atoms of the light-emitting gas are excited into an excimer state. When these atoms transition to the ground state, excimer light is emitted. In other words, the arc tube 30 constitutes part of an excimer lamp.

[0034] Due to excimer light emission, ultraviolet light L1 is emitted from the light emitting tube 30. This ultraviolet light L1 passes through the window member 5 and is extracted to the outside of the ultraviolet light irradiation device 1.

[0035] The type of luminous gas sealed in the light emitting tube 30 is selected according to the wavelength of the ultraviolet light L1 desired to be extracted from the window member 5. By setting the main peak wavelength of the ultraviolet light L1 to 240 nm or less, it is possible to contribute to sterilization and virus inactivation using the ultraviolet light L1 on the irradiation target. As an example, a mixed gas containing Kr and Cl, a mixed gas containing Kr and Br, a mixed gas containing Ar and F, etc. can be used as the luminous gas.

[0036] Preferably, the window member 5 is provided with a bandpass filter that blocks the transmission of light in the wavelength range of 240 nm to 280 nm. When the above-mentioned type of light-emitting gas is sealed inside the arc tube 30, the intensity of the ultraviolet light L1 emitted from the arc tube 30 in the wavelength range of 240 nm or more is extremely low or almost nonexistent. However, ultraviolet light in the wavelength range of 240 nm to 280 nm is known to have an effect on the human body. Therefore, by providing the window member 5 with a bandpass filter that suppresses the progression of ultraviolet light in this wavelength range, it becomes possible to irradiate ultraviolet light L1 during times when people are near the target of irradiation with almost no effect on the human body.

[0037] The bandpass filter can be realized, for example, by a dielectric multilayer film formed by alternately stacking films made of dielectric materials with different refractive indices. That is, a base material made of quartz glass or the like is used as the window member 5, and the dielectric multilayer film is stacked on the top surface of this base material to obtain a window member 5 equipped with a bandpass filter. Examples of the dielectric multilayer film that can be used include a laminate in which HfO2 layers and SiO2 layers are alternately stacked, or a laminate in which SiO2 layers and Al2O3 layers are alternately stacked. In addition to quartz glass, the base material of the window member 5 can also be made of ceramic or resin, as long as it is transparent to ultraviolet light L1.

[0038] In the following description, an XYZ coordinate system will be referred to as appropriate, in which the Z direction is the traveling direction of the ultraviolet light L1 extracted from the ultraviolet light irradiation device 1 through the window member 5, typically the normal direction to the surface of the window member 5, and the XY plane is the plane perpendicular to this Z direction. This coordinate system is also referenced and displayed in each of the drawings, including FIG. 1.

[0039] In this specification, when a positive or negative direction is to be distinguished when expressing a direction, the direction is described with a positive or negative sign, such as "+X direction" and "-X direction." When a direction is to be expressed without distinguishing between positive and negative directions, the direction is simply described as "X direction." In other words, in this specification, when simply described as "X direction," both the "+X direction" and the "-X direction" are included. The same applies to the Y direction and the Z direction.

[0040] Using the above notation, ultraviolet light L1 is extracted in the +Z direction from the ultraviolet light irradiation device 1. Furthermore, the first component 3 constituting the housing 2 is disposed adjacent to the second component 4 constituting the housing 2 on the +Z side.

[0041] Fig. 3 is a perspective view, similar to Fig. 2, that schematically shows the ultraviolet light irradiation device 1 shown in Fig. 1 in a state in which the first component 3 and the second component 4 have been separated, but is viewed from a different direction than Fig. 2. Fig. 4 is a perspective view that omits the second component 4 from Fig. 3 and shows the members housed inside the first component 3 in an exploded state.

[0042] As shown in FIGS. 3 and 4, in the ultraviolet light irradiation device 1 of this embodiment, a pair of sealing members 12 and 13 are arranged inside the first component 3 so as to sandwich the window member 5 in the Z direction.

[0043] Fig. 5 is a cross-sectional perspective view of only the first component 3, cut along a predetermined plane. Fig. 6 is a cross-sectional perspective view of the first component 3, with the window member 5 and the sealing members 12 and 13 housed inside, cut along the same position as in Fig. 5. Fig. 7 is an enlarged view of area α1 in Fig. 6.

[0044] As shown in Figures 4 and 5, an opening 6 is formed in a part of the first component 3 that constitutes the housing 2. Then, as shown in Figures 3 to 7, this opening 6 is closed by a window member 5.

[0045] 4 and 7, a first seal member 12 is in contact with the first surface 5a of the window member 5, and this first seal member 12 also in contact with the inner wall 3a of the first component 3. In other words, the first seal member 12 improves the adhesion between the window member 5 and the first component 3.

[0046] The first seal member 12 is preferably made of an elastically deformable material from the viewpoint of improving the adhesion between the window member 5 and the inner wall of the first component 3. Examples of such materials include various rubber materials such as ethylene propylene, nitrile, fluorine, silicone, and urethane, and various resin materials such as fluororesins typified by PTFE, polyamide, polyethylene, and polyacetal.

[0047] Furthermore, it is more preferable that the first seal member 12 is made of a breathable material. In this case, the first seal member 12 blocks water penetration while allowing gas (air) to pass through. Porous resin materials such as fluororesin, polyamide, polyethylene, polyacetal, and PTFE can be used as such materials. Typically, porous PTFE can be used as the material for the seal member.

[0048] 4, the first seal member 12 is frame-shaped and abuts against an area on the first surface 5a of the window member 5 close to the outer edge of the window member 5. That is, the first seal member 12 is disposed so as to abut against the first surface 5a of the window member 5 outside the area through which the ultraviolet light L1 passes through the window member 5 (i.e., the opening 6 in FIG. 4) on the XY plane.

[0049] In the ultraviolet light irradiation device 1 of this embodiment, the second seal member 13 abuts against the second surface 5b of the window member 5. However, the second seal member 13 is installed at a position away from the opening 6 provided in the first component 3 in the Z direction, and its function of closing the gap between the first component 3 and the window member 5 is relatively small compared to that of the first seal member 12. In other words, in the present invention, it is optional for the ultraviolet light irradiation device 1 to be provided with the second seal member 13. The second seal member 13 can be made of the same material as the first seal member 12.

[0050] Fig. 8 is a perspective view showing the first component 3 from a different direction than Fig. 2. That is, Fig. 8 is a perspective view schematically showing the second component 4 and elements housed inside the second component 4.

[0051] As shown in FIG. 8 , the second component 4 accommodates an arc tube 30 and a lamp holder 31 that supports the arc tube 30. In the ultraviolet light irradiation device 1 of this embodiment, a buffer member 32 made of a cushioning material is accommodated outside the lamp holder 31 as viewed in the Z direction. This buffer member 32 is provided to improve adhesion between the first component 3 and the second component 4 when they are fitted together. More specifically, as shown in FIGS. 3 and 4 , an uneven portion 19 is formed on the inner bottom wall of the first component 3 at a position outside the window member 5 as viewed in the Z direction. When the first component 3 and the second component 4 are fitted together, the buffer member 32 enters the uneven portion 19 by being pressed into the first component 3 and the second component 4, thereby improving adhesion between the first component 3 and the second component 4. However, in the present invention, it is optional for the ultraviolet light irradiation device 1 to include the uneven portion 19 and the buffer member 32.

[0052] Fig. 9 is a perspective view in which the buffer member 32 is omitted from Fig. 8. Fig. 10 is a perspective view in which the lamp holder 31 and the buffer member 32 are separated from the second part 4 from Fig. 8.

[0053] As shown in Figures 8 to 10, the lamp holder 31 provided in the ultraviolet light irradiation device 1 of this embodiment has a frame shape when viewed in the Z direction, and ultraviolet light L1 emitted from the light-emitting tube 30 exposed inside the lamp holder 31 travels in the +Z direction and is extracted to the outside of the ultraviolet light irradiation device 1 through the window member 5.

[0054] As shown in Fig. 10 , in this embodiment, a pair of electrodes 35, 36 are mounted inside the second component 4 at positions on the -Z side of the arc tube 30. The pair of electrodes 35, 36 are arranged spaced apart from each other in the axial direction of the arc tube 30, i.e., the Y direction. In other words, the pair of electrodes 35, 36 are in contact with the outer wall of the arc tube 30 at positions spaced apart from each other in the Y direction. Although not shown in Fig. 10 , an electrical component for applying a voltage to the pair of electrodes 35, 36 is mounted inside the second component 4. When a voltage is applied from the electrical component to the pair of electrodes 35, 36, ultraviolet light L1 is emitted from the arc tube 30.

[0055] The arc tube 30 is made of a material that has high mechanical strength, insulating properties, and functions as a dielectric, and is also transparent to the ultraviolet light L1. Typically, the arc tube 30 is made of fused silica glass or synthetic quartz glass. The pair of electrodes 35, 36 is made of a conductive material, typically a metal such as aluminum, an aluminum alloy, or stainless steel.

[0056] 10, a trigger member 38 is provided, which is located between a pair of electrodes 35, 36 and is electrically connected to one of the pair of electrodes 35, 36. This trigger member 38 is provided for the purpose of assisting the discharge within the arc tube 30 by initiating discharge earlier than the light-emitting gas within the arc tube 30. When a voltage is applied from the electrical component to the pair of electrodes 35, 36, a corona discharge is first generated in the trigger member 38, and light energy resulting from this corona discharge is irradiated into the arc tube 30, thereby assisting the excimer discharge of the light-emitting gas within the arc tube 30. As a result, ultraviolet light L1 is emitted from the arc tube 30 in a short period of time. However, in the present invention, it is optional whether or not the ultraviolet light irradiation device 1 includes the trigger member 38.

[0057] FIG. 11 is a schematic cross-sectional view of the ultraviolet light irradiation device 1 shown in FIG. 1, taken along the XZ plane at a location where the electrode 35 and the outer wall of the arc tube 30 are in contact with each other.

[0058] As described above, in the ultraviolet light irradiation device 1 of this embodiment, a pair of seal members 12, 13 are arranged inside the housing 2 so as to sandwich the window member 5 in the Z direction. The first seal member 12 abuts against the inner wall of the housing 2, more specifically, the inner wall 3a of the first part 3, thereby closing the gap between the window member 5 and the opening 6.

[0059] Furthermore, in the ultraviolet light irradiation device 1 of this embodiment, the second seal member 13 abuts against the outer wall 31a of the lamp holder 31 inside the housing 2. As a result, the first surface 5a of the window member 5 abuts against the inner wall of the housing 2, more specifically the inner wall 3a of the first component 3, via the first seal member 12, and the second surface 5b of the window member 5 abuts against the outer wall 31a of the lamp holder 31 via the second seal member 13. As a result, the window member 5 is stably supported within the housing 2, and the adhesion between the window member 5 and the housing 2 is improved.

[0060] As described above, according to the ultraviolet light irradiation device 1, the first sealing member 12 improves the adhesion between the window member 5 and the housing 2, making it less likely that a gap will form between the housing 2 and the window member 5 than in conventional devices. As a result, even when the ultraviolet light irradiation device 1 is installed near water or in a damp place, it can prevent water from entering the inside of the housing 2, and therefore the device can be used for the purpose of sterilizing or inactivating viruses in places where it was difficult to install conventional devices, such as near water or inside air conditioners.

[0061] [Another embodiment] Another embodiment will be described below.

[0062] <1> In the above-described configuration, the ultraviolet light irradiation device 1 has a single arc tube 30 inside the housing 2. However, an ultraviolet light irradiation device 1 in which multiple arc tubes 30, 30, ... are arranged inside the housing 2 is also within the scope of the present invention.

[0063] <2> In the above embodiment, the light source provided in the ultraviolet light irradiation device 1 is an excimer lamp including the arc tube 30. However, a similar function can be achieved by installing a substrate on which a plurality of solid-state light sources, such as LEDs or LDs, that emit ultraviolet light L1 are mounted, and an optical system, such as a diffuser or a lens that refracts light, in the space inside the housing 2 where the arc tube 30 and the pair of electrodes 35, 36 are disposed. In this case, the lamp holder 31 that was disposed inside the housing 2 may not be installed, or a support having a shape similar to that of the lamp holder 31 may be installed. In other words, even when the light source that emits ultraviolet light L1 is a solid-state light source, it is within the scope of the present invention.

[0064] <3> The present invention is not limited to the above-described embodiments and includes various modifications. For example, the above-described embodiments have been described in detail to provide a better understanding of the present invention, and the present invention is not necessarily limited to those having all of the configurations described. The scope of the present invention is defined by the claims, and it is intended to include all modifications within the meaning and scope of the claims. [Explanation of symbols]

[0065] 1: Ultraviolet light irradiation device 2: Housing 3: First part of the housing 3a: Inner wall of the first part 4: Second part of the housing 5: Window material 5a: First surface of window member 5b: Second surface of window member 6:Aperture 12: First sealing member 13: Second sealing member 19: Uneven part 30: Arc tube 31: Lamp holder 31a: Outer wall of lamp holder 32: Cushioning material 35: Electrode 36: Electrode 38: Trigger member L1: Ultraviolet light

Claims

1. a light source that emits ultraviolet light having a main peak wavelength of 240 nm or less; a housing that houses the light source; an opening provided in a portion of the housing; a window member made of a material that is transparent to ultraviolet light; a seal member disposed on a surface of the window member, the window member closes the opening while being in contact with the inner wall of the housing via the seal member; The ultraviolet light irradiation device is characterized in that the sealing member abuts against a surface of the window member outside the opening.

2. 2. The ultraviolet light irradiation device according to claim 1, wherein the sealing member is made of a breathable material.

3. 3. The ultraviolet light irradiation device according to claim 2, wherein the sealing member is made of porous PTFE.

4. 2. The ultraviolet light irradiation device according to claim 1, wherein the window member includes a bandpass filter that blocks transmission of light in a wavelength range of 240 nm to 280 nm.

5. 2. The ultraviolet light irradiation device according to claim 1, wherein the sealing member has a frame shape.

6. 2. The ultraviolet light irradiation device according to claim 1, wherein the light source is an excimer lamp including an arc tube filled with a mixed gas containing Kr and Cl or a mixed gas containing Kr and Br.

7. a lamp holder for supporting the arc tube; the sealing member includes a first sealing member disposed on a first surface of the window member and a second sealing member disposed on a second surface of the window member opposite to the first surface, the first seal member abuts against an inner wall of the housing; 7. The ultraviolet light irradiation device according to claim 6, wherein the second sealing member abuts against an outer wall of the lamp holder.

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