Ultraviolet irradiation device

Abstract

To provide an ultraviolet light irradiation device that allows greater freedom in selecting materials for the housing than ever before. [Solution] The ultraviolet light irradiation device comprises an arc tube filled with a light-emitting gas, a pair of electrodes that are in contact with the wall of the arc tube and are arranged spaced apart in the axial direction of the arc tube, a housing that houses the arc tube and the pair of electrodes, a light extraction window that is provided on part of the outer surface of the housing and that extracts ultraviolet light emitted from the arc tube to the outside of the housing, and a lamp holder that is housed within the housing and supports the arc tube from the side where the light extraction window is located, and the lamp holder has a first part that is a frame-shaped body that surrounds the pair of electrodes when viewed in the normal direction of the light extraction window, and at least a part of the arc tube is located inside the first part.

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] The ultraviolet light irradiation device described in Patent Document 1 has an excimer lamp housed in a housing, and ultraviolet light from the excimer lamp is extracted to the outside through a light extraction window provided in the housing.

[0005] While most of the ultraviolet light emitted from the excimer lamp travels toward the light extraction window, some of the ultraviolet light travels toward the wall of the housing where the light extraction window is not formed. As a result, as the device is used, the cumulative amount of ultraviolet light irradiated onto the housing increases, which may cause the housing to deteriorate over time. From this perspective, it is preferable to construct the housing from a material with high ultraviolet resistance.

[0006] When it is assumed that the ultraviolet light irradiation device will be installed in a narrow space or will be portable, it is preferable that the weight of the entire device is light. From this viewpoint, it is preferable that the housing is made of resin.

[0007] In view of the above, when realizing the ultraviolet light irradiation device of Patent Document 1 as a small and lightweight device, it is preferable to use a resin with high ultraviolet resistance as the material for the housing. An example of such a resin is PEI (polyetherimide).

[0008] However, resins with high UV resistance are limited, limiting the range of materials that can be used to construct the housing, which can lead to increased manufacturing costs for the device.

[0009] In view of the above-mentioned problems, an object of the present invention is to provide an ultraviolet light irradiation device that allows greater freedom in selecting materials for the housing than ever before. [Means for solving the problem]

[0010] The ultraviolet light irradiation device according to the present invention comprises: an arc tube filled with luminous gas; a pair of electrodes in contact with a tube wall of the arc tube and spaced apart from each other in the axial direction of the arc tube; a housing that accommodates the arc tube and the pair of electrodes; a light extraction window provided on a part of the outer surface of the housing, for extracting the ultraviolet light emitted from the light emitting tube to the outside of the housing; a lamp holder that is housed in the housing and supports the arc tube from the side where the light extraction window is located, the lamp holder has a first portion that is a frame-like body surrounding the pair of electrodes when viewed in a normal direction of the light extraction window, At least a part of the arc tube is located inside the part.

[0011] In this specification, the term "main peak wavelength" refers to the wavelength that exhibits the highest light intensity in the entire wavelength range.

[0012] 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.

[0013] In this specification, "exhibiting reflectivity" means that when light is incident on an object at an incident angle of 0°, the intensity of the light reflected from the object (reflected light) is 30% or more of the intensity of the incident light.

[0014] When a voltage is applied to a pair of electrodes, the voltage is applied through the tube wall to the light-emitting space filled with light-emitting gas, which excites the atoms contained in the light-emitting gas into an excimer state, and emits light when these atoms transition to the ground state (excimer emission).

[0015] The luminous gas used corresponds to the desired wavelength of ultraviolet light. For example, when a mixed gas containing Kr and Cl is used as the luminous gas, ultraviolet light with a main peak wavelength of approximately 222 nm is generated. Other examples of combinations of luminous gas and main peak wavelength include KrBr (approximately 207 nm) and ArF (approximately 193 nm). Ultraviolet light in these wavelength ranges can be used to inactivate bacteria and viruses in spaces or on the surfaces of objects. Note that the term "approximately" used in conjunction with the main peak wavelength is intended to include individual differences in lamp products. For example, a description that the main peak wavelength is approximately 222 nm not only refers to 222.0 nm in the absolute sense, but also allows for a wavelength deviation within a range of ±2.0 nm from 222.0 nm.

[0016] As another example, when a gas containing Xe as a main component is used as the light-emitting gas, ultraviolet light with a main peak wavelength of approximately 172 nm is generated. Here, by applying a phosphor to the wall surface of the light-emitting tube, the wavelength can be converted to a longer wavelength, and ultraviolet light in the wavelength range of approximately 200 nm to 240 nm can be emitted. In other words, the ultraviolet light irradiation device is not limited to the type of light-emitting gas sealed in the light-emitting tube. In this case, LaPO4:Pr, K2YF5:Pr, LaF3:Nd, etc. can be used as the phosphor.

[0017] In the ultraviolet light irradiation device described above, a lamp holder is disposed in a position close to the light extraction window side of the arc tube. This lamp holder has a first portion that is a frame-shaped body surrounding a pair of electrodes when viewed in the normal direction of the light extraction window, and at least a portion of the arc tube is located inside this first portion. That is, when a voltage is applied to the pair of electrodes, the region in the internal space of the arc tube to which voltage is applied, in other words, the region in the internal space of the arc tube that emits strong light (effective light-emitting region), is located inside the first portion of the lamp holder. As a result, the lamp holder does not obstruct the progression of the ultraviolet light to be extracted, and the ultraviolet light proceeds directly toward the light extraction window.

[0018] On the other hand, the ultraviolet light generated by the arc tube traveling in a direction different from the direction of the light extraction window is irradiated onto the wall of the lamp holder, more specifically, onto the wall of the first portion. Because the lamp holder is housed inside the housing, irradiation of the housing by the ultraviolet light can be prevented. Therefore, even if the housing is made of a material with low UV resistance, deterioration of the housing due to irradiation by ultraviolet light can be suppressed.

[0019] Because the lamp holder is a component housed inside the housing, it is less susceptible to deterioration than the housing, which may be touched by humans. Also, unlike the housing, because it is a part housed inside, it can be replaced periodically.

[0020] Furthermore, since the housing is arranged to cover the internal elements, including the arc tube and electrodes, it has a larger surface area and volume than the lamp holder. In other words, the lamp holder occupies a relatively small area compared to the housing. Therefore, even if the lamp holder is made of a material with high UV resistance, the manufacturing cost of the ultraviolet light irradiation device can be reduced compared to when the housing itself is made of a material with high UV resistance.

[0021] According to the above configuration, the housing can be made of a wide variety of materials. Examples of materials that can be used for the housing include one or more resin materials, such as polyvinyl chloride, polyethylene, polypropylene, polystyrene, acrylonitrile-butadiene-styrene, acrylonitrile-styrene, polymethyl methacrylic, polyethylene terephthalate, polyamide, polyacetal, polycarbonate, polyphenylene ether, acrylonitrile-EPDM-styrene, polybutylene terephthalate, polyvinylidene fluoride, polysulfone, epoxy resin, polyethersulfone, polyphenylene sulfide, polyarylate, polyamide-imide, polyetherimide, polyetheretherketone, polyimide, liquid crystal polymer, polytetrafluoroethylene, phenolic resin, urea resin, melamine resin, perfluoroalkoxyalkane, and ethylene tetrafluoroethylene copolymer. Furthermore, the housing can be made of the aforementioned resins with added fibers, such as glass fiber or carbon fiber, to increase its strength, or it can be coated with a known weather-resistant coating material. Furthermore, ceramic materials such as alumina, zirconia, etc. can also be used as the material for forming the housing. Since ceramic materials are more brittle than resin, resin is preferable as the material for forming the housing.

[0022] The housing is preferably made of a highly impact-resistant material because it is an element exposed to the space in which the ultraviolet light irradiation device is installed. From this perspective, among the above-mentioned materials, polyvinyl chloride, polypropylene, acrylonitrile-butadiene-styrene, polyethylene terephthalate, polyamide, polybutylene terephthalate, polyphenylene sulfide, polycarbonate, polyetherimide, and composite materials thereof are preferably used, and polycarbonate, acrylonitrile-butadiene-styrene, polyetherimide, and composite materials thereof are particularly preferred.

[0023] The lamp holder can also be made of the materials listed above as examples of materials for constructing the housing. However, since the lamp holder is irradiated with ultraviolet light from the light-emitting tube when the ultraviolet light irradiation device is in use, it is preferable to make it out of a material with relatively high ultraviolet resistance in order to reduce the frequency of component replacement. From this perspective, it is preferable to use acrylonitrile butadiene styrene, polyethylene terephthalate, polyamide, polybutylene terephthalate, polyphenylene sulfide, polycarbonate, polyetherimide, polyether ether ketone, polytetrafluoroethylene, perfluoroalkoxyalkane, and composite materials thereof, and it is particularly preferable to use polycarbonate, acrylonitrile butadiene styrene, polyetherimide, polytetrafluoroethylene, and composite materials thereof.

[0024] The lamp holder has a recess in a part thereof, The tube wall of the arc tube may be fitted into the recess.

[0025] This allows the lamp holder to reliably hold the arc tube within the housing while preventing ultraviolet light from traveling toward the inner wall of the housing.

[0026] the light extraction window includes an opening provided in a part of the housing, and a window member arranged to close the opening and made of a material that is transparent to the ultraviolet light, The window member may be in contact with the surface of the lamp holder opposite to the arc tube, either directly or via another member.

[0027] the housing includes a first component located closer to the light extraction window in a normal direction of the light extraction window and a second component located closer to the light-emitting tube, and the first component and the second component are configured to fit together in the normal direction of the light extraction window, the lamp holder includes a second portion connected to the first portion at a position outside the first portion with respect to the tube axis direction of the arc tube, a buffer member disposed in contact with a surface of the second portion of the lamp holder opposite to the arc tube; When the first component and the second component are fitted together, the buffer member may come into contact with an inner wall of the first component.

[0028] According to the above configuration, the housing includes two components, and these components are fitted together to form an internal storage space. Therefore, screwing and unscrewing operations are unnecessary when opening and closing the housing for manufacturing or component replacement. Furthermore, a buffer member is provided in the second portion of the lamp holder, preventing damage to the lamp holder and other components when fitting the two components of the housing together. Since the second portion of the lamp holder is located further outward than the first portion of the lamp holder in the axial direction of the arc tube, the possibility of UV light from the arc tube being irradiated therewith is extremely low. Therefore, the buffer member can be made of a material with cushioning properties and is not limited to a material with high UV resistance. Specifically, the buffer member can be made of various rubber materials, such as ethylene propylene, nitrile, fluorine, silicone, and urethane, as well as various resin materials, such as fluororesins, such as PTFE, polyamide, polyethylene, and polyacetal.

[0029] In the above configuration, the first component has an uneven portion formed by uneven processing on a part of an inner wall, When the first component and the second component are fitted together, the buffer member may come into contact with the uneven portion of the first component.

[0030] According to this configuration, when the first component and the second component are fitted together, the cushioning member deforms to fit into the uneven portion of the first component, thereby improving the adhesion between the two components.

[0031] each of the pair of electrodes has a recessed groove that conforms to the shape of the wall of the arc tube; The light-emitting tube may have a portion of its tube wall farther from the light extraction window fitted into the groove formed in each of the pair of electrodes, and a portion of its tube wall closer to the light extraction window fitted into the recess of the lamp holder.

[0032] According to the above configuration, the arc tube is held by the pair of electrodes and the lamp holder on both sides normal to the light extraction window, so that the arc tube is housed inside the housing in a highly stable state, and the position of the arc tube is prevented from shifting within the housing even when the device itself is carried around.

[0033] The ultraviolet light irradiation device is a first seal member disposed on a surface of the window member on the light extraction window side at an outer edge of the window member; a second seal member disposed on an outer edge of the window member on a surface of the window member opposite to the light extraction window, the first seal member abuts against an inner wall of the housing; The second sealing member may be configured to abut against an outer wall of the lamp holder.

[0034] 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 small gap is inevitably formed between the housing and the window member. For this reason, if the ultraviolet light irradiation device is installed in a wet area such as a washroom, kitchen, toilet, or bathroom, or in a humid place such as the inside of an air conditioner (hereinafter collectively referred to as a "water-existing place"), water may enter the inside of the device through this gap.

[0035] In contrast, according to the above configuration, a first seal member is installed on the surface of the window member at the outer edge thereof, and the window member and the inner wall of the housing are in contact with each other via the first seal member. This allows the first seal member to close any gaps that may exist between the window member and the housing. As a result, even if the ultraviolet light irradiation device is installed in a location where water is present, water can be prevented from entering the device.

[0036] Furthermore, according to the above configuration, the second seal member is in contact with the surface of the window member opposite to the surface in contact with the first seal member, and this second seal member is in contact with the outer wall of the lamp holder. As a result, the arc tube, lamp holder, second seal member, window member, first seal member, and housing are arranged in contact with each other in this order in the normal direction of the light extraction window (window member). As a result, the positions of the arc tube, lamp holder, second seal member, window member, and first seal member are stably maintained within the housing.

[0037] The first seal member is preferably made of an elastically deformable material to enhance adhesion between the window member and the inner wall of the housing. 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. The second seal member can also be selected from materials that can be used for the first seal member.

[0038] The window member may include a bandpass filter that blocks transmission of light in the wavelength range of 240 nm to 280 nm.

[0039] 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.

[0040] 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 using the ultraviolet light irradiation device for the purpose of sterilization or virus inactivation, the main peak wavelength is preferably 190 nm or more, and more preferably 200 nm or more.

[0041] The first seal member and the second seal member may be frame-shaped, thereby improving adhesion between the window member and the inner wall of the housing via the seal members. [Effects of the Invention]

[0042] According to the ultraviolet light irradiation device of the present invention, it is possible to increase the degree of freedom in selecting the material of the housing compared to the conventional art. [Brief explanation of the drawings]

[0043] [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 3A] 2 is a perspective view schematically showing a state in which various members, in addition to a first component 3 and a second component 4, are separated from the ultraviolet light irradiation device 1 shown in FIG. 1. FIG. [Figure 3B] 3A is a perspective view schematically showing a state in which some members are separated from the ultraviolet light irradiation device 1 shown in FIG. 1 in addition to the first component 3 and the second component 4, and is viewed from a different direction than FIG. 3A. [Figure 4] 1 is a perspective view showing the lamp holder 31 separated from the second part 4. FIG. [Figure 5] 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 6] FIG. 6 is an exploded perspective view of the members housed inside the first component 3, with the second component 4 omitted from FIG. 5. [Figure 7] FIG. 1 is a cross-sectional perspective view of only the first component 3, cut along a predetermined plane. [Figure 8] 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 9] FIG. 9 is an enlarged view of an area α1 in FIG. [Figure 10A] 3 is a perspective view showing the first component 3 from FIG. 2, but viewed from a different direction. [Figure 10B] FIG. 10B is a schematic plan view of the elements shown in FIG. 10A when viewed in the −Z direction. [Figure 11A] 10B is a perspective view of FIG. 10A in which the buffer member 32 is omitted. [Figure 11B] FIG. 11B is a schematic plan view of the elements shown in FIG. 11A when viewed in the −Z direction. [Figure 12] FIG. 2 is a schematic perspective view of a lamp holder 31. [Figure 13] FIG. 2 is a schematic perspective view of a pair of electrodes 35 and 36. [Figure 14] 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

[0044] 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.

[0045] 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.

[0046] The ultraviolet light irradiation device 1 accommodates various components in a housing 2. FIG. 3A is a perspective view schematically illustrating a state in which various components have been separated from the first component 3 and the second component 4 in FIG. 1. FIG. 3B is a perspective view schematically illustrating a state in which various components have been separated from the first component 3 and the second component 4, viewed from a different direction than FIG. 3A. However, unlike FIG. 3A, for convenience of explanation, FIG. 3B does not show exploded views of the components accommodated inside the second component 4.

[0047] As shown in FIGS. 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 FIGS. 2 to 3B, an arc tube 30 constituting the light source is housed inside the housing 2, more specifically, on the second component 4 side. That is, of the components constituting the housing 2, the first component 3 is the component located closer to the window member 5, and the second component 4 is the component located closer to the arc tube 30. The arc tube 30 is supported by a lamp holder 31. The window member 5 forms a light extraction window for extracting ultraviolet light L1 emitted from the arc tube 30 to the outside of the ultraviolet light irradiation device 1.

[0048] In the following description, an XYZ coordinate system will be referred to as appropriate, in which the Z direction is the direction of travel 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 (light extraction window) 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.

[0049] 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 referring to the "X direction," both the "+X direction" and the "-X direction" are included. The same applies to the Y direction and the Z direction. Using this coordinate system, the housing 2 is formed by fitting the first part 3 and the second part 4 in the Z direction, and ultraviolet light L1 is extracted from the ultraviolet light irradiation device 1 in the +Z direction.

[0050] Fig. 4 is a perspective view illustrating the lamp holder 31 separated from the second part 4 shown in Fig. 3B. In Fig. 4, as in Fig. 3B, the upward direction of the paper surface is the +Z direction.

[0051] 4, the outer wall of the arc tube 30 is in contact with a pair of electrodes 35, 36. 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 ultraviolet light L1. Typically, the arc tube 30 is made of fused silica glass or synthetic silica glass.

[0052] The pair of electrodes 35, 36 are arranged at positions spaced apart in the tube axis direction (Y direction) of the arc tube 30. 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 a part of an excimer lamp. Although not shown in FIG. 4, an electrical component for applying a voltage to the pair of electrodes 35, 36 may be housed inside the second component 4.

[0053] 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.

[0054] 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. For example, 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.

[0055] 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.

[0056] 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 ceramics or resin, as long as it is transparent to ultraviolet light L1.

[0057] Fig. 5 is a perspective view, similar to Fig. 2, that schematically shows the ultraviolet light irradiation device 1 shown in Fig. 1 with the first component 3 and the second component 4 separated, but is viewed from a different direction than Fig. 2. Fig. 6 is a perspective view that omits the second component 4 from Fig. 5 and shows the members housed inside the first component 3 in an exploded view.

[0058] 5 and 6, in the ultraviolet light irradiation device 1 of this embodiment, a pair of sealing members 12, 13 are arranged inside the first component 3 so as to sandwich the window member 5 in the Z direction. Hereinafter, the sealing member 12 will be referred to as the "first sealing member 12," and the sealing member 13 will be referred to as the "second sealing member 13."

[0059] Fig. 7 is a cross-sectional perspective view of only the first component 3, cut along a predetermined plane. Fig. 8 is a cross-sectional perspective view of the first component 3, with the window member 5, first seal member 12, and second seal member 13 housed inside, cut along the same position as in Fig. 7. Fig. 9 is an enlarged view of area α1 in Fig. 8.

[0060] As shown in Figures 6 to 7, an opening 6 is formed in a part of the first component 3 that constitutes the housing 2. Then, as shown in Figures 5 to 8, this opening 6 is closed by a window member 5.

[0061] 6 and 9, 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.

[0062] 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.

[0063] 6, the first sealing member 12 is frame-shaped and is in contact with 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 sealing member 12 is disposed so as to surround the area through which the ultraviolet light L1 passes through the window member 5 on the XY plane.

[0064] 5, 6, and 9, 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. Note that, as shown in FIG. 3B, the surface of the second seal member 13 opposite to the window member 5 abuts against the surface of the lamp holder 31. The second seal member 13 can be made of the same material as the first seal member 12.

[0065] Fig. 10A is a perspective view showing the first component 3 from Fig. 2, but viewed from a different direction. That is, Fig. 10A is a perspective view schematically showing the second component 4 and the elements housed inside the second component 4. Fig. 10B is a schematic plan view of the elements shown in Fig. 10A when viewed from the +Z side in the -Z direction.

[0066] 10A and 10B, the second part 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 material that exhibits cushioning properties is accommodated at a position outside the lamp holder 31 when viewed in the Z direction. The buffer member 32 is provided from the perspective of improving the adhesion between the first part 3 and the second part 4 when they are fitted together.

[0067] Fig. 11A is a perspective view of Fig. 10A with the buffer member 32 omitted. Fig. 11B is a schematic plan view of the elements shown in Fig. 11A when viewed in the -Z direction from the +Z side.

[0068] 11A and 11B, the lamp holder 31 includes a first portion 61 that is frame-shaped when viewed in the Z direction, and a second portion 62 that is connected to the first portion 61 on the outside in the Y direction. More specifically, the first portion 61 of the lamp holder 31 is frame-shaped when viewed in the Z direction, surrounding the pair of electrodes 35, 36.

[0069] When a voltage is applied between the pair of electrodes 35, 36, ultraviolet light L1 is generated within the arc tube 30. More specifically, within the light-emitting space within the arc tube 30, the area to which voltage is applied by the pair of electrodes 35, 36 mainly emits strong light. This space corresponds to the "effective light-emitting area."

[0070] In principle, the ultraviolet light L1 generated in the effective light-emitting region inside the arc tube 30 travels three-dimensionally. However, because a pair of electrodes 35, 36 are present at a position on the -Z side of the arc tube 30, when the ultraviolet light L1 is irradiated onto these electrodes, the ultraviolet light L1 is prevented from traveling further in the -Z direction. From the perspective of increasing the amount of ultraviolet light L1 extracted through the window member 5, the pair of electrodes 35, 36 are preferably made of a material that is reflective to the ultraviolet light L1, and typical examples include aluminum, an aluminum alloy, and stainless steel.

[0071] Furthermore, it is preferable to provide a separate reflector in a position on the -Z side of the arc tube 30 and in an area sandwiched between the pair of electrodes 35, 36 in the Y direction. This allows the ultraviolet light L1 emitted from the arc tube 30 and traveling in the -Z direction to be reflected in the +Z direction and directed toward the window member 5.

[0072] A portion of the ultraviolet light L1 generated in the effective light-emitting region within the arc tube 30 also travels in the direction along the XY plane. However, as described above, the frame-shaped first portion 61 of the lamp holder 31 is disposed outside the pair of electrodes 35, 36 in the direction along the XY plane. Therefore, the ultraviolet light L1 generated in the arc tube 30 and traveling in the direction along the XY plane is irradiated onto the lamp holder 31. As a result, irradiation of the wall surface of the housing 2 with the ultraviolet light L1 can be prevented. Therefore, the housing 2 does not necessarily need to be made of a material with high UV resistance; for example, a material with low UV resistance but excellent impact resistance can be selected.

[0073] On the other hand, since the lamp holder 31 is a component housed inside the housing 2, the impact of deterioration is relatively small compared to the housing 2 which may be touched directly by humans. Also, since the lamp holder 31 is a component housed inside the housing 2, even if it does deteriorate, it can be replaced periodically.

[0074] 3B, the end of the arc tube 30 in the Y direction is not surrounded by the lamp holder 31, and is positioned so as to face the inner wall of the second part 4 of the housing 2. However, because this region is outside the above-mentioned effective light-emitting region, the intensity of the ultraviolet light L1 traveling in the Y direction from the end of the arc tube 30 in the Y direction is extremely low. Therefore, even if the ultraviolet light L1 traveling in the Y direction from the end of the arc tube 30 in the Y direction is irradiated onto the housing 2 as the ultraviolet light irradiation device 1 is used, the amount of light is not enough to accelerate deterioration of the housing 2.

[0075] 10A and 10B is disposed in contact with the surface of the second portion 62 (see FIG. 11B) of the lamp holder 31. More specifically, a claw portion 33 is formed on part of the upper surface of the second portion 62 of the lamp holder 31, and the cushioning member 32 can be fixed by being hooked onto this claw portion 33.

[0076] 3B, when assembling the housing 2, the first part 3 and the second part 4 are fitted together in the Z direction. At this time, because the buffer member 32 is disposed on the upper surface of the lamp holder 31 on the +Z side, even if a strong stress is applied during fitting, the inner wall of the first part 3 comes into contact with the buffer member 32, and direct contact with the lamp holder 31 can be avoided, so that the lamp holder 31 can be prevented from being pressed and damaged or deformed.

[0077] Furthermore, as described above, the ultraviolet light L1 generated in the arc tube 30 and traveling in the direction along the XY plane is irradiated onto the first portion 61 of the lamp holder 31. The buffer member 32 is disposed on the second portion 62 of the lamp holder 31, which is positioned outward of the first portion 61 in the direction along the XY plane. As a result, irradiation of the ultraviolet light L1 onto the buffer member 32 can be suppressed. Therefore, the buffer member 32 can be made of a material having cushioning properties, and does not necessarily need to be made of a material with high UV resistance. Specifically, the buffer member 32 can be made of 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.

[0078] 3A, 5, and 6, the first component 3 of the housing 2 preferably has an uneven portion 19 formed by unevenly processing part of the inner wall. In this case, when the first component 3 and the second component 4 are fitted together in the Z direction, the buffer member 32 comes into contact with the uneven portion 19 and deforms along the shape of the uneven portion 19. This causes the first component 3 and the second component 4 to be firmly attached to each other.

[0079] When the first component 3 and the second component 4 are fitted together, the claws 53 of the first component 3 may be fitted into the claws 54 of the second component 4, as shown in Fig. 3A. With this configuration, the need for screwing and unscrewing is eliminated when opening and closing the housing 2. Furthermore, the need for screwing and unscrewing is eliminated when attaching and detaching the arc tube 30. However, from the viewpoint of minimizing the possibility of the first component 3 and the second component 4 being separated (disassembled) due to an external impact or the like, the first component 3 and the second component 4 may be fastened together with screws, and such a configuration is also within the scope of the present invention.

[0080] Fig. 12 is a schematic perspective view of the lamp holder 31. As shown in Fig. 12, the lamp holder 31 preferably has a recess 41 formed at an end position in the Y direction (see also Figs. 3A and 4). This recess 41 has a shape that follows the shape of the tube wall of the arc tube 30. This makes it possible to determine the position of the arc tube 30 by simply fitting the arc tube 30 into the recess 41 of the lamp holder 31.

[0081] Fig. 13 is a schematic perspective view of the pair of electrodes 35, 36. As shown in Fig. 13, the pair of electrodes 35, 36 preferably have a groove 42 formed in a portion thereof. This groove 42 has a shape that follows the shape of the tube wall of the arc tube 30. This allows the position of the arc tube 30 to be determined by fitting the arc tube 30 into the respective grooves 42 of the pair of electrodes 35, 36 and arranging the arc tube 30 so as to straddle the pair of electrodes 35, 36.

[0082] That is, according to the ultraviolet light irradiation device 1 of this embodiment, the arc tube 30 is supported from the -Z side by the pair of electrodes 35, 36, and from the +Z side by the lamp holder 31. This allows the arc tube 30 to be housed inside the housing 2 in a highly stable state.

[0083] 3A and 4, 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.

[0084] FIG. 14 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.

[0085] 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.

[0086] 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.

[0087] [Another embodiment] Another embodiment will be described below.

[0088] <1> In the above-described configuration, the ultraviolet light irradiation device 1 has a single arc tube 30 inside the housing 2. However, the scope of the present invention also includes an ultraviolet light irradiation device 1 in which multiple arc tubes 30, 30, ... are arranged inside the housing 2. In this case, the multiple arc tubes 30, 30, ... are typically arranged in the X direction.

[0089] <2> In the above-described configuration, the ultraviolet light irradiation device 1 is described as including the first sealing member 12, the second sealing member 13, and the buffer member 32, but an ultraviolet light irradiation device 1 that does not include some or all of these is also within the scope of the present invention.

[0090] <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]

[0091] 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: Lamp holder outer wall 32: Cushioning material 33: Claw part 35: Electrode 36: Electrode 38: Trigger member 41: Recess of lamp holder 42: Electrode groove 53: Claw part 54: Claw part 61: First part of lamp holder 62: Second part of lamp holder L1: Ultraviolet light

Claims

1. an arc tube filled with luminous gas; a pair of electrodes in contact with a tube wall of the arc tube and spaced apart from each other in the axial direction of the arc tube; a housing that accommodates the arc tube and the pair of electrodes; a light extraction window provided on a part of the outer surface of the housing, for extracting the ultraviolet light emitted from the light emitting tube to the outside of the housing; a lamp holder that is housed in the housing and supports the arc tube from the side where the light extraction window is located, the lamp holder has a first portion that is a frame-like body surrounding the pair of electrodes when viewed in a normal direction of the light extraction window, An ultraviolet light irradiation device, characterized in that at least a part of the arc tube is located inside the part.

2. The lamp holder has a recess in a part thereof, 2. The ultraviolet light irradiation device according to claim 1, wherein the wall of said light-emitting tube is fitted into said recess.

3. the light extraction window includes an opening provided in a part of the housing, and a window member arranged to close the opening and made of a material that is transparent to the ultraviolet light, 2. The ultraviolet light irradiation device according to claim 1, wherein the window member abuts against a surface of the lamp holder opposite to the arc tube, either directly or via another member.

4. the housing includes a first component located closer to the light extraction window in a normal direction of the light extraction window and a second component located closer to the light-emitting tube, and the first component and the second component are configured to fit together in the normal direction of the light extraction window, the lamp holder includes a second portion connected to the first portion at a position outside the first portion with respect to the tube axis direction of the arc tube, a buffer member disposed in contact with a surface of the second portion of the lamp holder opposite to the arc tube; 2. The ultraviolet light irradiation device according to claim 1, wherein the buffer member contacts an inner wall of the first part when the first part and the second part are fitted together.

5. the first component has an uneven portion formed by uneven processing on a part of an inner wall, 5. The ultraviolet light irradiation device according to claim 4, wherein when the first component and the second component are fitted together, the buffer member comes into contact with the uneven portion of the first component.

6. each of the pair of electrodes has a recessed groove that conforms to the shape of the wall of the arc tube; 3. The ultraviolet light irradiation device according to claim 2, wherein a portion of the tube wall of the light-emitting tube on the side farther from the light extraction window is fitted into the recess formed in each of the pair of electrodes, and a portion of the tube wall on the side closer to the light extraction window is fitted into the recess of the lamp holder.

7. a first seal member disposed on a surface of the window member on the light extraction window side at an outer edge of the window member; a second seal member disposed on an outer edge of the window member on a surface of the window member opposite to the light extraction window, the first seal member abuts against an inner wall of the housing; 4. The ultraviolet light irradiation device according to claim 3, wherein the second sealing member abuts against an outer wall of the lamp holder.

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