Inactivation device

Abstract

The invention provides an inactivation device which improves the intensity of ultraviolet light in a wavelength band having extremely small influence on a human body and maintains or suppresses the intensity of ultraviolet light in a wavelength band having influence on the human body. The present invention is provided with: an excimer lamp which has a light-emitting tube in which a light-emitting gas containing a rare gas and a halogen gas is sealed, and a pair of electrodes, and which, when a voltage is applied between the pair of electrodes, generates, in the light-emitting tube, ultraviolet light having a main emission wavelength band in the range of 190 nm or more and less than 240 nm; and an optical filter to which the ultraviolet light generated by the excimer lamp is incident, the ultraviolet light having a wavelength in the range of 190 nm or more and less than 240 nm being transmitted, and the ultraviolet light having a wavelength in the range of 240 nm or more and less than 280 nm being substantially non-transmitted. The sealing pressure ratio of the halogen gas to the rare gas in the light-emitting gas sealed in the light-emitting tube is 2% or more and less than 5%.

Description

Technical Field

[0001] The present invention relates to a device for inactivating bacteria or viruses, in particular to a device for inactivating bacteria or viruses using ultraviolet light. Background Art

[0002] In the past, there is a known technology for inactivating bacteria and viruses by irradiating ultraviolet light. Since DNA shows the highest absorption characteristics near the wavelength of 260nm, in most cases, ultraviolet light with a wavelength of about 254nm using a low-pressure mercury lamp or the like as a light source is used. The method of inactivating bacteria and viruses by ultraviolet light does not spread drugs, etc., and has the advantage of being able to sterilize the target space or object by irradiating ultraviolet light only.

[0003] Ultraviolet light has wavelength bands with a high risk of affecting the human body and wavelength bands with a low risk of affecting the human body. Therefore, methods and devices for inactivating bacteria and viruses present in a space by ultraviolet light of a wavelength band with a low risk of affecting the human body have been studied. For example, the following patent document 1 describes a sterilization device (inactivation device) that uses ultraviolet light with a wavelength of 190nm to 230nm that has a very low impact on the human body.

[0004] Prior art literature

[0005] Patent Literature

[0006] Patent Document 1: Japanese Patent No. 6025756 Summary of the invention

[0007] Problems to be solved by the invention

[0008] In recent years, research and verification on the effects of ultraviolet light on the human body have made progress, confirming that ultraviolet light is easily absorbed by the surface layer of the skin or the corneal epithelium, and the shorter the wavelength, the higher the safety.

[0009] It is confirmed that ultraviolet light with a wavelength below 240nm has a low risk of affecting the human body.

[0010] In addition, due to the recent spread of the new coronavirus infection, inactivation devices that utilize ultraviolet light in a wavelength band that has little impact on the human body have attracted particular attention. In order to introduce them into spaces where people frequently pass by, there is a desire for devices that are safer and can perform inactivation treatment more effectively.

[0011] In view of the above problems, an object of the present invention is to provide an inactivation device that increases the intensity of ultraviolet light in a wavelength band that has little effect on the human body and maintains or suppresses the intensity of ultraviolet light in a wavelength band that may affect the human body.

[0012] Means for solving problems

[0013] The deactivation device of the present invention is characterized in that it comprises:

[0014] An excimer lamp comprising a light-emitting tube in which a light-emitting gas including a rare gas and a halogen gas is sealed, and a pair of electrodes, wherein when a voltage is applied between the pair of electrodes, ultraviolet light having a main light-emitting wavelength band within a range of 190 nm to less than 240 nm is generated in the light-emitting tube; and

[0015] An optical filter into which the ultraviolet light generated by the excimer lamp is incident, wherein the ultraviolet light having a wavelength in the range of 190 nm to less than 240 nm is transmitted, and the ultraviolet light having a wavelength in the range of 240 nm to less than 280 nm is substantially not transmitted,

[0016] A ratio of a sealing pressure of the halogen gas in the light-emitting gas sealed in the light-emitting tube to a sealing pressure of the rare gas is 2% or more and less than 5%.

[0017] In this specification, "inactivation" is a concept including killing bacteria and viruses or eliminating their infectivity and toxicity, and "bacteria" refers to microorganisms such as bacteria or fungi (molds).

[0018] Hereinafter, "bacteria or viruses" may be collectively referred to as "bacteria, etc."

[0019] In this specification, the “main emission wavelength band” refers to a wavelength band showing a light intensity of 10% or more relative to the peak intensity in the intensity spectrum of light generated in the light emitting tube of the excimer lamp.

[0020] In addition, in this specification, "allowing ultraviolet light to pass" means that the intensity of ultraviolet light incident at an incident angle of 0° and emitted at an emission angle of 0° is maintained at 10% or more relative to the intensity of the peak wavelength. It should be noted that the intensity of ultraviolet light in the wavelength band that passes through the optical filter is preferably maintained at 10% or more relative to the intensity of the peak wavelength, and more preferably maintained at 20% or more. Moreover, "making ultraviolet light substantially non-transmittable" means that the intensity of ultraviolet light incident at an incident angle of 0° and emitted at an emission angle of 0° is suppressed to less than 5% relative to the intensity of the peak wavelength. It should be noted that the intensity of ultraviolet light in the wavelength band suppressed by the optical filter is preferably suppressed to less than 2% relative to the intensity of the peak wavelength, and more preferably suppressed to less than 1%.

[0021] First, the characteristics of an excimer lamp including a light-emitting tube in which a light-emitting gas containing rare gas atoms (Ng) and halogen atoms (X) is sealed will be described.

[0022] When a voltage above a specified threshold is applied between a pair of electrodes of an excimer lamp, a discharge is generated in the light-emitting tube. Then, the rare gas atoms and halogen atoms contained in the light-emitting gas are ionized or excited by the discharge, and an excited complex is formed in the light-emitting tube as shown in the following formula (1). The excited complex is an extremely unstable molecule, and immediately after its formation, it dissociates into rare gas atoms and halogen atoms as shown in the following formula (2). Moreover, when the dissociation occurs, light corresponding to the amount of energy released (also called "quasi-molecular light") is generated. The (*) in the following formula indicates an excited state. It should be noted that the reaction formulas shown below are formulas representing a representative portion of the reactions that participate in the generation of excimer light among the various reactions occurring in the light-emitting tube.

[0023] Ng * +X2→NgX * +X (1)

[0024] Nx * →Ng+X+hν (2)

[0025] The light generated by the reactions shown in the above equations (1) and (2) is generally light belonging to the main emission wavelength band among the light generated in the light emitting tube.

[0026] In the light emitting tube, depending on the combination of atoms contained in the light emitting gas and the sealing pressure, the reactions represented by the above-mentioned formulas (1) and (2) and the reactions represented by the following formulas (3) and (4) may occur.

[0027] NgX*+2Ng→Ng2X * +Ng (3)

[0028] N2X * →2Ng+X+hν (4)

[0029] The light generated by the reaction shown in the above formula (3) and formula (4) generally has less energy than the light of the main emission wavelength band in the light generated in the light emitting tube, and becomes light on the longer wavelength side than the main emission wavelength band. For example, in the case of an excimer lamp in which the rare gas is krypton (Kr) and the halogen gas is chlorine (Cl), the reaction shown in the above formula (3) and formula (4) generates light of about 222 nm, and the reaction shown in the above formula (3) and formula (4) generates light of about 315 nm.

[0030] Ultraviolet light with a wavelength of around 315 nm is light of a wavelength band that causes sunburn when irradiated to the human body. However, the intensity of ultraviolet light with a wavelength of around 315 nm emitted from the excimer lamp of this configuration is very weak compared to the intensity of light belonging to the main emission wavelength band.

[0031] Furthermore, even if the excimer lamp is constructed so as to emit light having a main emission wavelength band within the range of 190 nm or more and less than 240 nm, in most cases, it will inevitably generate ultraviolet light within the wavelength band of 240 nm or more and 280 nm or more, which is particularly harmful to the human body. Such ultraviolet light within the wavelength range of 240 nm or more and 280 nm is usually dealt with by providing an optical filter that substantially does not transmit ultraviolet light in this wavelength band.

[0032] Here, the actual situation and trend of inactivation devices using ultraviolet light are described. As described above, inactivation devices using ultraviolet light of a wavelength band that has little effect on the human body are expected to suppress contact infection via the surface of objects or infection via aerosols present in space, so research is being conducted on introducing them into spaces where people frequently come and go or spaces where people work for a long time.

[0033] However, ultraviolet light with a wavelength of more than 190nm and less than 240nm has a very small impact on the human body compared to ultraviolet light emitted from a low-pressure mercury lamp. Considering safety, a limit value for the cumulative exposure to the human body is set. At the time of filing this application, it is recommended that the cumulative exposure to ultraviolet light irradiated to the human body be set within the limit value (permissible limit value) specified by ACGIH (American Conference of Governmental Industrial Hygienists). For example, the permissible limit value for the cumulative exposure to ultraviolet light with a wavelength of 222nm per day (8 hours) is specified as 22mJ / cm 2 It should be noted that the allowable limit values ​​in this specification are current values ​​and may be changed in the future. In addition, it is not limited to the above, and it is preferred to set a prescribed upper limit value for the cumulative exposure of ultraviolet light to the human body in terms of safe operation.

[0034] Therefore, a deactivation device that is assumed to irradiate ultraviolet light to a space where people come and go is required to be able to effectively deactivate the treatment target space and the treatment target object while complying with the above-mentioned limit value of the cumulative exposure amount of ultraviolet light.

[0035] As described above, regarding the excimer lamp that emits ultraviolet light whose main emission wavelength band is between 190 nm and below 240 nm, the light having a wavelength of about 315 nm is very weak compared to the intensity of the ultraviolet light belonging to the main emission wavelength band. Moreover, the intensity of ultraviolet light having a wavelength between 240 nm and 280 nm is sufficiently reduced by passing through an optical filter.

[0036] Therefore, when an excimer lamp emitting ultraviolet light having a main emission wavelength band of 190 nm to less than 240 nm is used and inactivation treatment is performed in compliance with the current permissible limit values, the effect on the human body is basically not a problem.

[0037] However, due to the recent spread of the new coronavirus infection, the inactivation of bacteria using ultraviolet light has attracted attention, and based on the background that the safety of ultraviolet light in specific wavelength bands has been confirmed through various verification experiments, research is currently underway to relax the allowable limit value of the cumulative exposure to ultraviolet light in some wavelength bands for humans.

[0038] In view of the actual situation as described above, it is predicted that in order to more effectively deactivate the target space and the object, the deactivation device using ultraviolet light will implement the use scheme of irradiating with higher intensity ultraviolet light and constantly lighting the space where people come and go in the future.

[0039] Therefore, even if the risk of harming human health is not a problem at present, it is expected to become a problem in the future based on the re-evaluation of the permissible limit value when it is introduced into a space where people frequently pass by. In other words, if the limit value of the cumulative exposure amount is likely to be relaxed in the future, it is expected that the inactivation device using ultraviolet light will be required to increase the intensity of ultraviolet light in the wavelength band that has little effect on the human body, and maintain or reduce the intensity of ultraviolet light in the wavelength band that has an impact on the human body.

[0040] Ultraviolet light in the wavelength range of 240 nm to 280 nm has a particularly large impact on the human body compared to ultraviolet light in other wavelength ranges, so it is considered to focus on implementing countermeasures by making efforts in the structure and materials of optical filters.

[0041] However, it is very difficult to configure an optical filter so as to satisfy desired transmittance characteristics in the entire wavelength band of ultraviolet light. If an optical filter attempts to reduce the transmittance of a specific wavelength band, the transmittance of light in other wavelength bands may inevitably increase.

[0042] Therefore, with regard to the previous inactivation device, it is possible to emit ultraviolet light with a wavelength of more than 280nm, especially ultraviolet light with a wavelength of about 300nm as mentioned above, with high intensity while increasing the intensity of light emitted from the excimer lamp and reducing the transmittance of ultraviolet light with a wavelength of more than 240nm and less than 280nm as much as possible.

[0043] Therefore, the inventors focused on the fact that the light generated in the light-emitting tube of an excimer lamp is generated based on the reactions shown in the above equations (1) to (4), and studied a method of controlling the spectrum of ultraviolet light by adjusting the sealing pressure of the rare gas and halogen gas of the light-emitting gas sealed in the light-emitting tube.

[0044] The inventors conducted a verification experiment to confirm how the spectrum of light generated in the light-emitting tube of an excimer lamp changes with changes in the ratio of the sealing pressure of the rare gas and the halogen gas sealed in the light-emitting tube. The details of this verification experiment will be described in the section "Specific embodiments".

[0045] The results of this verification experiment confirmed that the ratio of the sealing pressure of the halogen gas to the sealing pressure of the rare gas in the light-emitting gas (hereinafter also referred to as "sealing pressure ratio") is preferably 2% or more and less than 5%.

[0046] In summary, by setting the above configuration, with respect to the relative intensity to the peak intensity of the ultraviolet light emitted through the optical filter, the intensity of the ultraviolet light on the longer wavelength side compared to the main emission wavelength band can be reduced without greatly increasing the intensity of the ultraviolet light in the wavelength band harmful to the human body, i.e., the wavelength domain with a wavelength of 240 nm or more and less than 280 nm. That is, the light intensity of the ultraviolet light in the main emission wavelength domain belonging to the wavelength band of 190 nm or more and less than 240 nm can be increased, and the intensity of the ultraviolet light in the wavelength band harmful to the human body can be maintained or reduced.

[0047] In the above-mentioned inactivation device,

[0048] The optical filter may have a band that transmits ultraviolet light in at least a portion of a wavelength range of 280 nm to less than 320 nm.

[0049] Dielectric multilayer film filters can adjust the wavelength band of transmitted ultraviolet light by adjusting the film thickness and the number of layers. Therefore, dielectric multilayer film filters are mostly used as bandpass filters for ultraviolet light. However, it is sometimes difficult to design dielectric multilayer film filters to meet the desired specifications for both the transmitted wavelength band and the substantially non-transmitted wavelength band. For example, if the dielectric multilayer film filter is constructed in such a way that ultraviolet light belonging to a wavelength band of more than 190nm and less than 240nm is transmitted and ultraviolet light belonging to a wavelength band of more than 240nm and less than 280nm is substantially non-transmitted, then in most cases, a band that allows light to be transmitted appears in the band with a wavelength of more than 280nm (refer to Fig. 6A ).

[0050] The dielectric multilayer filter has the following characteristics: if the bandwidth of the wavelength band that is substantially not transmitted is to be increased, the transmittance to the ultraviolet light with a wavelength of 190 nm or more and less than 240 nm that needs to be transmitted is reduced. In particular, it is not realistic to configure the filter in such a way that the entire band of light belonging to the ultraviolet region with a wavelength of 280 nm or more is substantially not transmitted, because the transmittance to the ultraviolet light with a wavelength of 190 nm or more and less than 240 nm is greatly reduced.

[0051] Thus, by setting the inactivation device as described above, it is possible to suppress the ultraviolet light in the wavelength band of 240 nm or more and less than 280 nm from irradiating a person, and it is also possible to suppress the ultraviolet light irradiation that may affect the human body due to the reaction of the above formula (3) and formula (4). It should be noted that, from the perspective of further improving safety, the optical filter is preferably a dielectric multilayer film filter that substantially does not transmit ultraviolet light in the range of 280 nm or more and less than 350 nm.

[0052] In the above-mentioned inactivation device,

[0053] The above-mentioned light-emitting gas may be a mixed gas containing krypton (Kr) and chlorine (Cl).

[0054] Furthermore, in the above-mentioned inactivation device,

[0055] The above-mentioned light-emitting gas may be a mixed gas containing krypton (Kr) and bromine (Br).

[0056] It should be noted that the target product of the present invention can provide the inherent sterilization and virus inactivation capabilities of ultraviolet light without causing erythema or keratitis to the skin and eyes of humans and animals. In particular, unlike conventional ultraviolet light sources, the product can be used in human environments. By being installed in human environments indoors or outdoors, the product can irradiate the entire environment and provide virus suppression / sterilization of the air and surfaces of components installed in the environment.

[0057] This corresponds to Goal 3 of the Sustainable Development Goals (SDGs) led by the United Nations, "Ensure healthy lives and promote well-being for all at all ages", and will also greatly contribute to Goal 3.3, "By 2030, eliminate communicable diseases such as AIDS, tuberculosis, malaria and neglected tropical diseases, and combat hepatitis, waterborne infections and other infections."

[0058] Effects of the Invention

[0059] According to the present invention, it is possible to realize an inactivation device which increases the intensity of ultraviolet light in a wavelength band that has little effect on the human body and maintains or suppresses the intensity of ultraviolet light in a wavelength band that may affect the human body. BRIEF DESCRIPTION OF THE DRAWINGS

[0060] Figure 1 This is a diagram schematically showing the appearance of one embodiment of a deactivation device.

[0061] Figure 2 Observed along the X direction Figure 1 Cross-sectional view of the inactivated device.

[0062] Figure 3 yes Figure 2 Magnified view of the excimer lamp surrounding.

[0063] Figure 4 yes Figure 2 Magnified image of the excimer lamp.

[0064] Figure 5 This is a graph showing an example of the spectrum of ultraviolet light generated in the light emitting tube of an excimer lamp.

[0065] Fig. 6A This is a graph showing the transmittance characteristics of the optical filter in one embodiment.

[0066] Figure 6B This is a graph showing an example of the spectrum of light emitted from an excimer lamp and passed through an optical filter.

[0067] Figure 7 This is a graph in which the relative intensity of the excimer lamp of each experimental sample in the wavelength range of 280 nm or longer and less than 320 nm is plotted.

[0068] Fig. 8A It is the relative intensity spectrum of the ultraviolet light emitted from the excimer lamp of the experimental sample in the wavelength range of 230nm to 280nm.

[0069] Figure 8B It is the relative intensity spectrum of the ultraviolet light emitted from the excimer lamp of the experimental sample in the wavelength range of 250nm to 400nm.

[0070] Fig. 9 This is a diagram schematically showing the appearance of one embodiment of a deactivation device.

[0071] Fig.10 Observed from the +Z side Fig. 9 Figure 2 shows the inactive device.

[0072] Fig.11 Observed along the X direction Fig. 9 Cross-sectional view of the inactivated device.

[0073] Fig.12 yes Fig.11 Magnified view of the excimer lamp surrounding. DETAILED DESCRIPTION

[0074] [First embodiment]

[0075] Figure 1 2 is a diagram schematically showing the appearance of a first embodiment of the deactivation device 1. Figure 2 It is a cross-sectional view when the inactivated device 1 is viewed along the X direction. Figure 3 yes Figure 2 An enlarged view of the periphery of the excimer lamp 30, Figure 4 yes Figure 2 The inactivation device 1 of the first embodiment is as shown in FIG. Figure 1 As shown in FIG. 1 , the frame 10 and the light-transmitting window 20 are provided. Figure 2 As shown in FIG. 1 , an excimer lamp 30 is accommodated in the housing 10 .

[0076] The first embodiment of the deactivation device 1 presents a shape that assumes a use scenario of irradiating human skin with ultraviolet light to perform local sterilization. It should be noted that the implementation scheme of the deactivation device 1 is not limited to this scheme, and of course, it is also assumed that the deactivation device 1 is fixed to the ceiling, wall, or pole in a specified divided space to perform sterilization in the space. In addition, the shape of the deactivation device 1, the arrangement position of each component, etc., can be designed into any shape according to the use strategy.

[0077] In the following description, Figure 2 As shown in FIG. 1 , the direction in which the excimer lamp 30 extends is set as the Y direction, the direction in which the light-transmitting window 20 and the excimer lamp 30 face each other is set as the Z direction, and the direction orthogonal to the Y direction and the Z direction is set as the X direction for description.

[0078] In addition, when describing a direction, when the positive and negative directions are distinguished, the positive and negative signs are marked and described, such as "+Z direction" and "-Z direction", and when the direction is described without distinguishing the positive and negative directions, it is simply described as "Z direction". Figure 3 As shown in , the direction in which the ultraviolet light is taken out corresponds to the "+Z direction".

[0079] The excimer lamp 30 of the first embodiment is as follows Figure 3 As shown in the figure, the excimer lamp includes a light emitting tube 30a and a pair of electrodes 30b facing each other in the radial direction via the light emitting tube 30a. It should be noted that the excimer lamp 30 in the first embodiment is an excimer lamp in which the light emitting tube 30a is cylindrical, also called a double tube shape. In order to take out the ultraviolet light generated inside the light emitting tube 30a to the outside, the outer electrode 30b of the excimer lamp 30 of this shape is formed by a metal wire processed into a mesh shape.

[0080] Figure 5 : is a graph showing an example of the spectrum of ultraviolet light generated in the light emitting tube 30 a of the excimer lamp 30 . Figure 5 In the graph shown in , the vertical axis represents the relative intensity when the peak intensity (light intensity at a wavelength of 222 nm) is set to 100%, and the horizontal axis represents the wavelength. The excimer lamp 30 of the first embodiment has a light-emitting gas G1 containing a mixed gas of krypton (Kr) gas and chlorine (Cl) gas sealed in a light-emitting tube 30a, and a voltage is applied between electrodes (30b, 30b) to generate a light emission in the light-emitting tube 30a. Figure 5 Ultraviolet light with a spectrum like that shown in . Figure 5 The graph shown in is a graph measured using a spectroradiometer (specifically, "USR-45DA" manufactured by Ushio Electric Co., Ltd.).

[0081] It should be noted that the light emitting gas G1 sealed in the light emitting tube 30 a contains krypton gas and chlorine gas, and argon (Ar) gas as a buffer gas so that the total sealing pressure becomes 200 torr.

[0082] The main emission wavelength band of the excimer lamp 30 in the first embodiment is as follows: Figure 5 The main emission wavelength band of the excimer lamp 30 is preferably within the wavelength range of 190 nm to 240 nm, which has little effect on the human body and confirms the effect of inactivation treatment, and more preferably within the wavelength range of 200 nm to 230 nm.

[0083] In this embodiment, the luminous gas G1 sealed in the luminous tube 30a is adjusted according to the sealing pressure (P Cl ) relative to the sealing pressure of krypton gas (P Kr ) ratio (P Cl / P Kr ) becomes 3.33% in a way to adjust.

[0084] The sealing pressure (P Kr , P Cl ) is measured by destroying the light emitting tube 30a contained in a vacuum container and using gas chromatography.

[0085] The light transmission window 20 is a light emission window for extracting ultraviolet light emitted from the excimer lamp 30 to the outside of the housing 10. The light transmission window 20 of the first embodiment has an optical filter 20b made of a dielectric multilayer film formed on a main surface 20a.

[0086] Inactivation device 1 Figure 5 The ultraviolet spectrum shown in Figure 3After the optical filter 20b described below, it is taken out from the light transmission window 20 to the outside of the frame 10. Figure 4 In the present invention, the ultraviolet light generated by the excimer lamp 30 is described as "ultraviolet light Lx", and the ultraviolet light that passes through the light-transmitting window 20 and is taken out to the outside of the inactivation device 1 is described as "ultraviolet light L1", thereby distinguishing the two. The same expressions are used appropriately below.

[0087] The light-transmitting window 20 is made of a material that can transmit ultraviolet light having a wavelength in a wavelength band of 190 nm or more and less than 240 nm. Specific materials for the light-transmitting window 20 include, for example, ceramic materials such as quartz glass, borosilicate glass, sapphire, magnesium fluoride materials, calcium fluoride materials, lithium fluoride materials, and barium fluoride materials, and resin materials such as silicone resin and fluororesin.

[0088] In addition, the optical filter 20b of the first embodiment is as follows Figure 3 As shown in FIG. 2 , the optical filter 20 is formed on the main surface 20a of the light-transmitting window 20, but may be formed on the main surface 20c on the opposite side of the main surface 20a of the light-transmitting window 20. Furthermore, in the case where the optical filter 20b does not require a glass plate or the like and can be mounted as a single body, the light-transmitting window 20 may be formed only of the optical filter 20b.

[0089] In the first embodiment, the length of the tube axis direction (Y direction) of the light emitting tube 30a of the excimer lamp 30 is 120 mm, the distance between the excimer lamp 30 and the optical filter 20b is 40 mm, and the size of the optical filter 20b is (X, Y) = (50 mm, 50 mm). It should be noted that the various dimensional structures described here are simply examples, and the various dimensions are optional.

[0090] Fig. 6A : is a graph showing the transmittance characteristics of the optical filter 20b in the first embodiment. Fig. 6A In the graph shown in , the vertical axis represents the transmittance of the optical filter 20b, and the horizontal axis represents the wavelength. Fig. 6A The graph is obtained by measuring the spectral spectrum of light incident on the optical filter 20b at an incident angle of 0° and the spectral spectrum of light emitted from the optical filter 20b at an emission angle of 0° using a spectrophotometer (specifically, "V-7200" manufactured by JASCO Corporation).

[0091] The optical filter 20b in the first embodiment is formed by using a dielectric multilayer film, such as Fig. 6A As shown in , it is configured to transmit ultraviolet light having a wavelength of 210 nm or more and less than 240 nm, and substantially not transmit ultraviolet light having a wavelength of 240 nm or more and less than 280 nm. Fig. 6A As shown in , the optical filter 20b transmits ultraviolet light having a wavelength of 280 nm or more and less than 400 nm.

[0092] Figure 6B : is a graph showing an example of the spectrum of light emitted from the excimer lamp 30 and passing through the optical filter 20b. Figure 6B The spectrum shown in confirms the use of optical filter 20b, with Figure 5 Compared with the graph shown in , the intensity in the wavelength range of 240 nm or more and less than 280 nm is reduced. Figure 6B The diagram shown in is the same as Figure 5 This is a graph measured in the same manner using a spectroradiometer (specifically, "USR-45DA" manufactured by Ushio Electric Co., Ltd.).

[0093] The optical filter 20b composed of a dielectric multilayer film can adjust the wavelength band that is transmitted and the wavelength band that is substantially not transmitted by finely adjusting the film thickness of each film constituting the dielectric multilayer film. As the material of each layer constituting the dielectric multilayer film, for example, silicon dioxide (SiO2), hafnium dioxide (HfO2), aluminum oxide (Al2O3), titanium dioxide (TiO2), zirconium oxide (ZrO2) and the like can be listed.

[0094] [Verification experiment]

[0095] Here, the intensity spectrum of the ultraviolet light Lx emitted from the excimer lamp 30 and the sealing pressure ratio (Pc l / P Kr ) is a verification experiment of the relationship, so the experiment is explained.

[0096] (Verification method)

[0097] The sealing pressure (P) of the krypton (Kr) gas contained in the light emitting gas G1 sealed in the light emitting tube 30a of the excimer lamp 30 is Kr ) and the sealing pressure of chlorine (C1) gas (P Cl ) and the sealing pressure ratio (P Cl / P Kr ) are set as shown in the following Table 1. It should be noted that, as described above, the luminous gas G1 sealed in the luminous tube 30a contains argon (Ar) gas as a buffer gas, and the overall sealing pressure is adjusted to 200 torr in any sample.

[0098] [Table 1]

[0099] sample <![CDATA[P Kr (torr)]]> <![CDATA[P Cl (torr)]]> <![CDATA[P cl / P Kr ]]> Example 1 120 4.0 3.33％ Example 2 142 2.9 2.04％ Comparative Example 1 176 1.2 0.68％ Comparative Example 2 188 0.6 0.32％ Comparative Example 3 196 0.2 0.10％

[0100] The light intensity was measured at a position 50 mm away from the light emitting tube 30a of the excimer lamp 30. It should be noted that the purpose of this verification is to confirm the sealing pressure ratio (P Cl / P Kr ) is related to the spectrum of the ultraviolet light emitted from the excimer lamp 30, and is therefore performed without the optical filter 20b.

[0101] (Verification results)

[0102] Figure 7 This is a graph obtained by plotting the relative intensity of the wavelength range of 280 nm or more and less than 320 nm for each sample shown in Table 1 above. Figure 7 The relative intensity shown in is the integrated value of the light intensity in the wavelength range of 280 nm to less than 320 nm when the integrated value of the light intensity in the wavelength range of 222 nm±5 nm is normalized to 1. Fig. 8A The relative intensity spectra of the ultraviolet light Lx emitted from the samples of Example 1 and Comparative Example 1 shown in Table 1 above in the wavelength range of 230 nm to 280 nm are shown in Table 1 above. Figure 8B The relative intensity spectra of the ultraviolet light Lx emitted from the samples of Example 1 and Comparative Example 1 shown in Table 1 above in the wavelength range of 250nm to 400nm. It should be noted that the relative intensity spectrum of the ultraviolet light emitted from the excimer lamp 30 of Example 1 in the wavelength range of 200nm to 400nm is Figure 5 Spectra shown in .

[0103] like Figure 7 As shown in the figure, the sealing pressure ratio (P Cl / P Kr ) is 2% or more, the integral of the light intensity in the wavelength range of 280nm to less than 320nm is less than 0.01, and the sealing pressure ratio (P Cl / P Kr ) has basically not changed. That is, according to Figure 7 , sealing pressure ratio (P Cl / P Kr ) is around 1.5%, the relative strength becomes less than 0.01, but due to manufacturing inequality, the relative strength may exceed 0.01. Cl / P Kr ) is 2.0% or more, even taking into account manufacturing variations, the possibility of the relative strength exceeding 0.01 is extremely small.

[0104] like Fig. 8A and Figure 8BAs shown in , the intensity spectrum of the excimer lamp 30 of Example 1 is higher in relative intensity in the wavelength range of 240 nm to less than 280 nm, and lower in relative intensity in the wavelength range of 280 nm to less than 400 nm, compared with the intensity spectrum of the excimer lamp 30 of Comparative Example 1.

[0105] The above results show that the sealing pressure ratio (P Cl / P Kr ) becomes larger, the relative intensity of the ultraviolet light Lx generated in the light-emitting tube 30a in the range of wavelengths greater than 240nm and less than 280nm increases, and the relative intensity in the range of wavelengths greater than 280nm and less than 400nm decreases.

[0106] That is, it is confirmed that by adjusting the sealing pressure ratio (P Cl / P Kr ), it is possible to control the relative intensity of the ultraviolet light Lx generated in the light emitting tube 30a within a wavelength range of greater than 240nm and less than 400nm.

[0107] Here, as described above, most of the excimer lamps are combined with an optical filter that substantially does not transmit light in the wavelength band that is harmful to the human body in order to prevent ultraviolet light in the wavelength band that is harmful to the human body from being irradiated to the human body.

[0108] In addition, it shows Fig. 6A For a dielectric multilayer film filter having a transmittance characteristic as shown in , an increase in transmittance is confirmed from a wavelength of about 280 nm toward the long wavelength side. When such a dielectric multilayer film filter is used, the possibility that ultraviolet light on the long wavelength side of 300 nm becomes a problem is high compared to the relative intensity of wavelengths of more than 240 nm and less than 280 nm.

[0109] Therefore, it is considered that the sealing pressure ratio (P Cl / P Kr ) is preferably adjusted in a manner to reduce the relative intensity of ultraviolet light on the longer wavelength side than 300 nm.

[0110] Furthermore, during the implementation of this verification experiment, the following phenomenon was confirmed: if the sealing pressure ratio of the luminescent gas G1 sealed in the luminescent tube 30a of the excimer lamp 30 is gradually increased, the excimer lamp becomes difficult to light when the sealing pressure ratio exceeds 5%. Halogen gases such as chlorine have high electronegativity and high electron adhesion. Therefore, if the pressure ratio of the chlorine gas in the luminescent tube 30a becomes higher, the electrons in the luminescent tube 30a become easier to adhere to the chlorine, and the number of electrons required for discharge decreases. It is inferred that the above phenomenon is caused by the reduction of electrons in the luminescent tube 30a in this way. Therefore, the sealing pressure ratio (P of the krypton gas to the chlorine gas contained in the luminescent gas G1) is increased. Cl / P Kr ) is preferably less than 5%.

[0111] It should be noted that the electron adhesion of chlorine gas also contributes to the stability of the discharge column in the arc tube 30a and the electrical load given to the lamp. Therefore, if the amount of chlorine gas is too small relative to the amount of krypton gas, the discharge generated in the arc tube 30a will become unstable and the life of the lamp will be shortened. Figure 7 The results of the above analysis are comprehensively judged, and the sealing pressure ratio (P Cl / P Kr ) is preferably 2% or more and less than 5%.

[0112] According to the above configuration, with respect to the relative intensity of the peak intensity of the ultraviolet light emitted after passing through the optical filter 20b, the intensity of the ultraviolet light on the long wavelength side compared with the main emission wavelength band can be reduced without greatly increasing the intensity of the ultraviolet light in the wavelength band harmful to the human body, i.e., the wavelength range of 240 nm or more and less than 280 nm. That is, the light intensity of the ultraviolet light in the main emission wavelength band belonging to the wavelength band of 190 nm or more and less than 240 nm can be increased, and the intensity of the ultraviolet light in the wavelength band harmful to the human body can be maintained or reduced.

[0113] It should be noted that the characteristics of the ultraviolet light Lx emitted from the excimer lamp 30 shown in the above verification are considered to be similarly present in an excimer lamp in which a light-emitting gas containing a rare gas and a halogen gas is sealed in a light-emitting tube. In particular, the same characteristics are confirmed in an excimer lamp in which a light-emitting gas G1 containing krypton gas and bromine (Br) gas is sealed in a light-emitting tube 30a and which emits ultraviolet light having a main light emission wavelength of approximately 207 nm.

[0114] That is, the inactivation device 1 of the present invention can also be equipped with an excimer lamp in which the luminous gas G1 containing rare gas and halogen gas is sealed in the luminous tube 30a. As a specific example, an excimer lamp 30 in which the luminous gas G1 containing krypton gas and bromine gas is sealed in the luminous tube 30a can be used.

[0115] In addition, by adjusting the light-emitting gas G1 sealed in the light-emitting tube 30a of the excimer lamp 30, when the intensity is sufficiently reduced to a level where there is no problem even if ultraviolet light with a wavelength of greater than 280nm and less than 400nm is directly emitted, an optical filter having a frequency band that allows ultraviolet light to pass within the wavelength range of greater than 280nm and less than 320nm can be used.

[0116] [Second embodiment]

[0117] The configuration of the second embodiment of the deactivation device 1 of the present invention will be described focusing on differences from the first embodiment.

[0118] Fig. 9 2 is a diagram schematically showing the appearance of a second embodiment of the deactivation device 1. Fig.10 Observed from the +Z side Fig. 9 FIG. 1 is a diagram of the inactive device 1. Fig.11 Observed along the X direction Fig. 9 A cross-sectional view of the inactivated device 1, Fig.12 yes Fig.11 An enlarged view of the periphery of the excimer lamp 30 is shown.

[0119] The second embodiment of the inactivation device 1 is assumed to be placed on a table or the like and irradiated with ultraviolet light toward a predetermined partitioned space.

[0120] The excimer lamp 30 of the second embodiment is as follows Fig. 9 As shown in FIG. 1 , the excimer lamp includes a plurality of light emitting tubes 30a and a pair of electrodes 30b. Fig.10 As shown in , it is placed on a pair of electrodes 30b.

[0121] The optical filter 20b of the second embodiment is as follows Fig.11 As shown in , it is formed on the main surface 20a of the light-transmitting window 20. This structure is the same as that of the first embodiment, but in the second embodiment, the length of the light-emitting tube 30a of the excimer lamp 30 in the tube axis direction (Y direction) is 70mm, the distance between the excimer lamp 30 and the optical filter 20b is 8mm, and the size of the optical filter 20b is (X, Y) = (60mm, 45mm).

[0122] The configuration of the deactivation device 1 described above is merely an example, and the present invention is not limited to the configurations shown in the drawings.

[0123] Explanation of symbols

[0124] 1: Inactive device

[0125] 10: Frame

[0126] 20: Light-transmitting window

[0127] 20a: Main surface

[0128] 20b: Optical filter

[0129] 20c: Main surface

[0130] 30: Excimer lamp

[0131] 30a: LED

[0132] 30b: Electrode

[0133] G1: Glowing Gas

[0134] L1, Lx: Ultraviolet light

Claims

1. A deactivation device, characterized in that: It has: An excimer lamp, the excimer lamp comprising a light-emitting tube in which a light-emitting gas including a rare gas and a halogen gas is sealed, and a pair of electrodes, wherein when a voltage is applied between the pair of electrodes, ultraviolet light having a main light-emitting wavelength band within a range of 190 nm or more and less than 240 nm is generated in the light-emitting tube; and The optical filter into which the ultraviolet light generated by the excimer lamp is incident, wherein the ultraviolet light having a wavelength in the range of 190 nm to less than 240 nm is transmitted, and the ultraviolet light having a wavelength in the range of 240 nm to less than 280 nm is substantially not transmitted, A ratio of a sealing pressure of the halogen gas in the light-emitting gas sealed in the light-emitting tube to a sealing pressure of the rare gas is 2% or more and less than 5%.

2. The deactivation device according to claim 1, characterized in that: The optical filter has a band that transmits ultraviolet light in at least a portion of a wavelength range of 280 nm to less than 320 nm.

3. The deactivation device according to any one of claims 1 to 3, characterized in that: The luminescent gas is a mixed gas containing krypton (Kr) and chlorine (Cl).

4. The deactivation device according to any one of claims 1 to 3, characterized in that: The luminescent gas is a mixed gas containing krypton (Kr) and bromine (Br).

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