JP2022082620A - Ultraviolet light irradiation device, and method for use of ultraviolet light irradiation device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an ultraviolet light irradiation device capable of effectively deactivating microbes and a method for use of the ultraviolet light irradiation device.

SOLUTION: An ultraviolet light irradiation device comprises: a light source for radiating ultraviolet light having a main emission wavelength of 190 nm to 235 nm; a housing for housing the light source; a take-out portion for taking out the ultraviolet light radiated from the light source to the outside of the housing; and a diffusion member for diffusing the ultraviolet light.

SELECTED DRAWING: Figure 4

COPYRIGHT: (C)2022,JPO&INPIT

Description

The present invention relates to an ultraviolet light irradiation device and a method of using the ultraviolet light irradiation device.

Microorganisms such as bacteria, fungi and viruses are known to exhibit the highest absorption properties near a wavelength of 260 nm. Therefore, a technique for inactivating microorganisms by irradiating the surface or space of an object in which microorganisms are present with ultraviolet light showing a high emission spectrum near a wavelength of 254 nm has been conventionally known.

For example, Patent Document 1 describes that a sterilizing lamp that emits ultraviolet light is attached to a kitchen or the like to sterilize the kitchen. Further, Patent Document 2 describes that bacteria and viruses floating in a room are sterilized by irradiating them with ultraviolet light.

In addition, the ultraviolet light irradiation device described in Patent Document 1 and Patent Document 2 uses ultraviolet light harmful to the human body. Therefore, measures are taken such as giving directivity to the emitted ultraviolet light so that the ultraviolet light does not go toward the human body.

Jikkai Sho 63-187221 JP-A-2017-018442

However, microorganisms such as bacteria, fungi and viruses are particularly abundant on the surface of the human body (eg, skin and hair), on the surface of objects with which humans frequently come into contact (eg, furniture and office equipment), or in spaces near the human body. ..

Due to the danger of irradiating the human body with harmful ultraviolet light, conventional ultraviolet light irradiation devices should most inactivate microorganisms such as the surface of the human body, the surface of objects with which humans frequently come into contact, and the space near the human body. It was not possible to irradiate the essential location with ultraviolet light. Therefore, the conventional ultraviolet light irradiation device has a limit in inactivating microorganisms.

The present invention provides an ultraviolet light irradiation device capable of effectively inactivating microorganisms while ensuring safety to the human body, and a method of using the ultraviolet light irradiation device.

Ultraviolet light is not harmful to the human body in all wavelength bands. UVC waves of 240 nm or more have been reported to be harmful to human cells, but ultraviolet light having a shorter wavelength band has a smaller penetrating power to human cells, so that the harmfulness to the human body is extremely low. Therefore, the present inventor has focused on using ultraviolet light having a main emission wavelength of 190 nm to 235 nm in order to inactivate microorganisms while suppressing harmful effects on the human body.

The ultraviolet light irradiation device of the present invention is
A light source that emits ultraviolet light whose main emission wavelength is 190 nm to 235 nm,
A housing that houses the light source and
An extraction unit that takes out the ultraviolet light radiated from the light source to the outside of the housing, and
The diffuser member for diffusing the ultraviolet light is provided.

Since this ultraviolet light irradiation device suppresses ultraviolet light in a wavelength band of 240 nm or more, which is harmful to the human body, it is possible to expand the light distribution angle of ultraviolet light by using a diffusing member. As a result, the area where you want to inactivate microorganisms (including the surface of the human body, the surface of objects that people frequently come into contact with, the space near the human body, or the space where people are absent) is widespread and even (smaller unevenness). ) Can irradiate ultraviolet light. Therefore, it is possible to effectively inactivate microorganisms while ensuring safety for the human body.

In the present specification, microorganisms refer to all prokaryotic organisms having a cell structure such as bacteria which are prokaryotes and fungi such as fungi which are eukaryotes, and DNA or RNA nucleic acids as a genome having no cell structure. It contains a virus that has.

As used herein, inactivation refers to either killing a prokaryote by destroying intracellular DNA or enzyme (protein) or cell membrane, or removing the proliferative function of the cell. Inactivation refers to the loss of infectivity to cells by destroying DNA or RNA in the case of viruses.

In the present specification, the "main emission wavelength" is 40% or more with respect to the total integrated intensity in the emission spectrum when the wavelength range Z (λ) of ± 10 nm with respect to a certain wavelength λ is defined on the emission spectrum. Refers to the wavelength λi in the wavelength region Z (λi) indicating the integrated intensity of. For example, in a light source having an extremely narrow half-value width and showing light intensity only at a specific wavelength, such as an excimer lamp in which a light emitting gas containing KrCl, KrBr, and ArF is enclosed, the relative intensity is usually the highest. A high wavelength (main peak wavelength) may be used as the main emission wavelength.

The ultraviolet light irradiation device may further include an optical filter that transmits ultraviolet light in a wavelength band of 190 nm or more and 230 nm or less, and substantially does not transmit ultraviolet light in a wavelength band of 240 nm to 300 nm. Safety to the human body is improved by not transmitting ultraviolet light in the wavelength band of 240 nm to 300 nm, which may affect the human body.

The optical filter and the diffusion member may be arranged in the extraction portion, and the optical filter may be located between the light source and the diffusion member.

The ultraviolet light irradiation device may further include a reflection member that reflects the light emitted from the light source in the housing. This increases the illuminance of the light emitted from the ultraviolet light irradiation device.

The diffusion member may be made of a material mainly made of quartz glass, a fluororesin, polyethylene or PET.

In the method of using the ultraviolet light irradiation device of the present invention, the ultraviolet light irradiation device is arranged so that at least a part of the emitted ultraviolet light is directed toward a manned space, and the ultraviolet light irradiation device is provided with the ultraviolet light. Irradiate with light.

It is possible to provide an ultraviolet light irradiation device capable of effectively inactivating microorganisms and a method of using the ultraviolet light irradiation device.

It is a perspective view which shows typically the appearance of the ultraviolet light irradiation apparatus. It is a perspective view which shows typically the appearance of the ultraviolet light irradiation apparatus. It is a perspective view which shows only the light source and the electrode block taken out from the ultraviolet light irradiation apparatus. It is sectional drawing in the XY plane of the ultraviolet light irradiation apparatus. It is a figure explaining the expansion action of the light distribution angle of the emitted light by a diffusing member. This is an example of the emission spectrum of an excimer lamp containing KrCl in the emission gas. It is a graph which shows an example of the transmission spectrum of an optical filter. It is a schematic drawing for demonstrating the incident angle of ultraviolet light with respect to an optical filter. It is a figure which shows typically the measuring equipment for measuring the action of a diffusion member. It is a graph which shows the relative illuminance with respect to the change of the angle of rotation in the ultraviolet light irradiation apparatus which does not have an optical filter. It is a graph which shows the relative illuminance with respect to the change of the angle of rotation in the ultraviolet light irradiation apparatus which has an optical filter.

Each embodiment of the ultraviolet light irradiation apparatus will be described with reference to the drawings. It should be noted that the following drawings are schematically shown, and the dimensional ratios on the drawings do not always match the actual dimensional ratios, and the dimensional ratios do not always match between the drawings.

In the following, each drawing will be described with reference to the XYZ coordinate system as appropriate. In the XYZ coordinate system, the direction in which the light beam on the optical axis of the emitted ultraviolet light travels is the + X direction, and the plane orthogonal to the X direction is the YZ plane. In addition, in this specification, when the positive and negative directions are distinguished when expressing a direction, it is described with positive and negative reference numerals such as "+ X direction" and "-X direction". When expressing a direction without distinguishing between positive and negative directions, it is simply described as "X direction". That is, in the present specification, when simply described as "X direction", both "+ X direction" and "-X direction" are included. The same applies to the Y direction and the Z direction.

<First Embodiment>
[Overview of UV irradiation device]
An embodiment of the ultraviolet light irradiation device of the present invention will be described with reference to FIGS. 1, 2 and 3. 1 and 2 are perspective views schematically showing the appearance of the ultraviolet light irradiation device. FIG. 3 is a diagram showing only the light source and the electrode block taken out from the ultraviolet light irradiation device.

The ultraviolet light irradiation device 10 of the present embodiment emits an excimer lamp 3 (see FIG. 2 or 3) that emits ultraviolet light, a housing 2 that houses the excimer lamp 3, and ultraviolet light emitted from the excimer lamp 3. It has a take-out portion 4 that is taken out of the housing 2 in the + X direction, a diffuser member 5 that diffuses ultraviolet light, and an optical filter 6 that will be described later. In FIGS. 1 and 2, the arrow L1 indicates the optical axis of the ultraviolet light emitted from the excimer lamp 3 and the traveling direction of the light ray on the optical axis.

In the present embodiment, the housing 2 is composed of a first frame 2a having an opening which is an opening portion 4 in the center and a second frame 2b having no opening, and the second frame 2b and the first frame 2a. And are fitted together to form an internal space surrounded by the housing 2. In this internal space, an excimer lamp 3 and two electrode blocks (9a, 9b) for supplying electric power to the excimer lamp 3 are arranged.

The two electrode blocks (9a, 9b) are fixed to the surface of the second frame 2b in contact with the internal space (see FIGS. 2 and 3). Two connection terminals (8a, 8b) are provided on the surface in contact with the outside of the second frame 2b. The two connection terminals (8a, 8b) are electrically connected to the electrode block (9a, 9b) with the second frame 2b interposed therebetween. Feed lines (7a, 7b) supplied from an external power source (not shown) are connected to the two connection terminals (8a, 8b), respectively. The two electrode blocks (9a, 9b) are made of a conductive material (for example, Al, Al alloy, stainless steel, etc.).

[light source]
An embodiment of the excimer lamp 3 will be described with reference to FIG. In the present embodiment, as the excimer lamp 3, three excimer lamps 3 (3a, 3b, 3c) arranged apart from each other in the Z direction are provided. The two electrode blocks (9a, 9b) come into contact with the outer surface of the arc tube of each excimer lamp 3 (3a, 3b, 3c). As a result, the excimer lamp 3 is powered and turned on.

In the present embodiment, the excimer lamp 3 uses a KrCl excimer lamp in which a luminescent gas containing KrCl is sealed inside the arc tube. Therefore, the excimer lamp 3 emits ultraviolet light having a main peak wavelength of 190 nm to 230 nm. In particular, the KrCl excimer lamp emits ultraviolet light having a main peak wavelength of around 222 nm.

The excimer lamp 3 is not limited to the KrCl excimer lamp. For example, a KrBr excimer lamp in which a light emitting gas containing KrBr is sealed inside the arc tube may be used. The KrBr excimer lamp emits ultraviolet light having a main peak wavelength of around 207 nm.

The size of the arc tube of the excimer lamp 3 (3a, 3b, 3c) is preferably such that the length in the tube axis direction (Y direction) is 15 mm or more and 200 mm or less, and the outer diameter is 2 mm or more and 16 mm or less.

[Diffusion member]
FIG. 4 is a schematic cross-sectional view of the ultraviolet light irradiation device 10 in the XZ plane. In the ultraviolet light irradiation device 10 of the present embodiment, a diffusion member 5 for diffusing ultraviolet light and an optical filter 6 are arranged in an opening constituting the extraction unit 4. In addition, "arranged in the extraction portion" means that the diffusion member 5 or the optical filter 6 is completely integrated with the light extraction surface, and the diffusion member 5 or the optical filter 6 is arranged on the light extraction surface. This includes the case where the light is arranged at a position separated by a small distance (for example, several mm ■ ten and several mm) in the X direction.

The light emitted from the excimer lamp 3 (3a, 3b, 3c) is blocked by the optical filter 6 for a specific wavelength band. Details of the optical filter 6 will be described later. The light beam bundle F1 emitted from the optical filter 6 is diffused by the diffusing member 5, and the angle at which the light spreads, that is, the light distribution angle becomes large.

With reference to FIG. 5, the expansion of the light distribution angle of the emitted light, which is the action of the diffusion member 5, will be described. In FIG. 5, if the diffuser member is not provided, the ultraviolet light bundle F2 is emitted from the ultraviolet light irradiation device 10 at a light distribution angle θ2 about the optical axis (arrow L1). When the diffuser member 5 is provided, the ultraviolet light bundle F1 is emitted at the light distribution angle θ1. The light distribution angle θ1 when the diffuser member 5 is provided is larger than the light distribution angle θ2 when the diffuser member 5 is not provided. The light distribution angle (θ1, θ2) is defined as the angle formed by the outermost opposed rays of the light beam bundles (F1, F2) extending around the optical axis, which are the farthest from the optical axis. The ray bundles (F1 and F2) are defined as a bundle of light rays that extends around the optical axis that is the center and has a brightness of 1/2 or more with respect to the brightness of the light rays on the optical axis L1.

The ultraviolet light irradiating device 10 can irradiate ultraviolet light over a wide range by expanding the orientation angle of the emitted light with the diffusing member 5. This makes it possible to cover the area where the microorganisms are to be inactivated with a small number of ultraviolet light irradiation devices, which is excellent in cost effectiveness.

Next, the suppression of unevenness of emitted light, which is another function of the diffusion member 5, will be described. If there is no unevenness (or the unevenness is small), the region that receives weak light locally is reduced, so that the region where the inactivating effect is small is reduced. Furthermore, since the area that receives strong light locally is reduced, it is less likely to be restricted by the upper limit of the irradiation amount of ultraviolet light while ensuring safety at a higher level. This will be described in detail below.

Ultraviolet light irradiation to the environment including humans may be required to suppress the irradiation amount. For example, in ACGIH (American Conference of Governmental Industrial Hygienists) or JIS Z 8812 (measurement method of harmful ultraviolet radiation), the amount of ultraviolet light irradiation to the human body per day (8 hours) is determined. It is specified so that it is equal to or less than the allowable limit value (TLV: Threshold Limit Value) for each wavelength.

As described above, the wavelength of the emitted light used in the present invention is a wavelength having extremely low harmfulness to the human body, but in order to further enhance safety, ultraviolet light is used so as to satisfy the above-mentioned TLV regulations. It is desirable to set the irradiation amount.

The large unevenness of the emitted light indicates that the intensity difference between the region that receives locally strong light and the region that receives locally weak light is large. When setting the irradiation amount of ultraviolet light so as to satisfy the above-mentioned TLV regulation, it is desirable to set it according to the region that receives strong light locally. Then, it becomes easy to be restricted by the upper limit of the ultraviolet light irradiation amount.

On the contrary, when the unevenness of the emitted light becomes small, the difference in light intensity for each region becomes small, and it becomes difficult to be restricted by the upper limit of the ultraviolet light irradiation amount. Therefore, the ultraviolet light irradiation device 10 suppresses the unevenness of the emitted light by the diffusing member 5, thereby ensuring safety at a higher level and making it less likely to be restricted by the upper limit of the ultraviolet light irradiation amount.

In order to ensure safety at a higher level, the diffuser member 5 may suppress the local maximum illuminance of ultraviolet light (the illuminance in the local region where the highest intensity light is irradiated). For example, the material, thickness, shape, etc. of the diffusing member may be selected or adjusted so as to suppress the local maximum illuminance of ultraviolet light on the light emitting surface of the diffusing member 5 to 1 mW / cm ² or less.

As the diffusion member 5, from the viewpoint of inactivating microorganisms by irradiation with ultraviolet light, a member having a transparency to ultraviolet light having a wavelength of 190 nm to 235 nm is used. The diffusion member 5 may be a member that suppresses the transmission of ultraviolet light having a wavelength other than 190 nm to 235 nm.

The diffusing member 5 may have a diffusing effect not only on ultraviolet light but also on visible light. The ultraviolet light irradiation device 10 described in the present invention is expected to be applied to various places and equipment. If the excimer lamp 3 and the electrode block inside the ultraviolet light irradiation device 10 are clearly identified, the surrounding landscape and the appearance of the equipment may be impaired. However, if the diffuser member having a diffusing effect on visible light is placed in the extraction unit 4, the excimer lamp 3 inside the ultraviolet light irradiation device 10 can be made invisible or clearly invisible, and the surroundings can be made invisible. It is possible to inactivate microorganisms while harmonizing with the landscape and the appearance of the equipment.

The shape and thickness of the diffusion member 5 are not particularly limited, and may be, for example, a film or a plate. The diffusion member 5 is, for example, provided with fine irregularities on the surface of the base material that transmits ultraviolet light, or by mixing voids or substances having different refractive indexes inside the base material that transmits ultraviolet light. It is formed. Fine irregularities may be formed by partially scraping the surface of the base material by etching treatment or blasting treatment, or by partially adding (or printing) particles such as resin to the surface of the base material. ) It may be formed.

The material of the diffusion member 5 may be, for example, a resin such as polycarbonate, polyethylene or PET, or a material mainly composed of a fluororesin such as PTFE, PFA or PVDF, or a material mainly composed of glass such as quartz glass. It doesn't matter. PTFE and quartz glass are particularly excellent as materials for the diffusion member 5 in that they are less likely to deteriorate over time.

[Optical filter]
The optical filter 6 functions as a bandpass filter that blocks ultraviolet light in a specific wavelength band, that is, does not substantially transmit the ultraviolet light. For example, in the case of a KrCl excimer lamp, as shown in FIG. 6, while the light output is concentrated in the vicinity of 222 nm, which is almost the main peak wavelength, in the spectrum of emitted ultraviolet light, it may affect the human body. Even for ultraviolet light in the wavelength band of 240 nm or more and 300 nm or less, a slight amount of light output is observed. In the present embodiment, the optical filter 6 is provided in the region constituting the extraction unit 4 so as to substantially prevent ultraviolet light of 240 nm or more and 300 nm or less from being transmitted. This further improves the safety of the ultraviolet light irradiation device for the human body.

As used herein, "substantially not transmitting ultraviolet light" means that the ultraviolet intensity is suppressed to at least 5% or less of the ultraviolet intensity of the peak wavelength in the wavelength band of 190 nm to 235 nm. .. In the present invention, by using an optical filter, the intensity of ultraviolet light of 240 nm or more and 300 nm or less is shielded to 5% or less of the intensity of the peak wavelength. It is more preferable that the intensity of the ultraviolet light transmitted through the optical filter is suppressed to 2% or less of the intensity of the peak wavelength for the light in the wavelength band to be shielded by the optical filter.

By the way, the optical filter 6 may be composed of a plurality of dielectric multilayer films having different refractive indexes, but the filter composed of the dielectric multilayer films has a transmittance depending on the incident angle of ultraviolet light. It will change inevitably.

FIG. 7 is a graph showing an example of the transmission spectrum of the optical filter 6 according to the incident angle when ultraviolet light is incident on the optical filter 6. In the example of this graph, the optical filter 6 is designed assuming that the emission gas of the excimer lamp 3 contains KrCl, that is, the excimer lamp 3 emits ultraviolet light having a main peak wavelength of 222 nm. Each curve in the graph is obtained by plotting the ratio of the intensity of the light incident on the optical filter 6 to the intensity of the light emitted from the optical filter 6 while changing the wavelength. As shown in FIG. 8, the incident angle is defined by the angle θ3 between the normal line 6N with respect to the incident surface of the optical filter 6 and the ultraviolet light L2 incident on the incident surface of the optical filter 6.

From the graph of FIG. 7, it can be seen that the optical filter 6 easily transmits a light component having a small incident angle (angle θ3), but does not easily transmit a light component having a large incident angle. As a result, the light emitted from the optical filter 6 has a higher proportion of light components having a smaller incident angle than the incident light on the optical filter 6, and the light distribution angle becomes smaller. In other words, the optical filter 6 reduces the light distribution angle of light.

Under such circumstances, the above-mentioned diffusion member 5 can obtain a particularly remarkable effect when the optical filter 6 for reducing the light distribution angle is used. That is, even when the light distribution angle is reduced by using the optical filter 6, the diffuser member 5 is arranged after the optical filter 6 (that is, the optical filter 6 is placed between the excimer lamp 3 and the diffuser member 5). (Arrangement), the ultraviolet light irradiation device 10 can obtain a large light distribution angle. However, the optical filter 6 is not an essential configuration in the ultraviolet light irradiation device 10.

[how to use]
As a mode of use of the ultraviolet light irradiating device according to the present invention, the ultraviolet light emitted can be arranged so as to be irradiated toward a manned space, and the ultraviolet light irradiating device can be irradiated with the ultraviolet light. A manned space means a space that people can enter regardless of whether or not there are actually people. The manned space includes, for example, a space in a building such as a house, an office, a school, a hospital or a theater, or a space in a vehicle such as a car, a bus, a train or an airplane. The ultraviolet light irradiation device 10 is arranged on a ceiling, a wall, a pillar, a floor, or the like facing the manned space so that the taking-out portion 4 faces the manned space. Then, the ultraviolet light irradiation device 10 is turned on to irradiate the manned space with ultraviolet light.

In this usage method, it is not necessary to avoid the human body and irradiate ultraviolet light as in the past, and the surface of the human body (skin, etc.), which is the most important place to inactivate microorganisms, is in frequent contact with humans. It is possible to irradiate the entire manned space, including the surface of an object or the space near the human body, with ultraviolet light evenly (with less unevenness). Therefore, the inactivation of microorganisms can be effectively performed.

The ultraviolet light irradiation device may be incorporated in a lighting facility such as a fluorescent lamp or an LED. When built in the lighting equipment, the diffuser member used in the ultraviolet light irradiation device may be shared with the diffuser member for visible light used in the lighting equipment.

Although the embodiment of the method of using the ultraviolet light irradiation device and the ultraviolet light irradiation device has been described above, the present invention is not limited to the above-described embodiment and is not deviated from the gist of the present invention. Various changes or improvements can be made to the above embodiments.

For example, although the example of using the excimer lamp 3 as the light source has been described, a solid-state light source composed of LD or LED may be used as the light source.

For example, a light source that emits ultraviolet light having a main emission wavelength of 190 nm to 230 nm may be used. Ultraviolet light having an upper limit of the main emission wavelength of 230 nm is more safe to the human body than ultraviolet light having an upper limit of the main emission wavelength of 235 nm.

For example, a light source that emits ultraviolet light having a main emission wavelength of 200 nm to 230 nm may be used. Ultraviolet light having a lower limit of the main emission wavelength of 200 nm has a lower ability to decompose oxygen in the atmosphere to generate ozone than ultraviolet light having a lower limit of the main emission wavelength of 190 nm. Since a gas with a high ozone concentration is harmful to the human body, suppressing the generation of ozone further enhances the safety to the human body.

For example, as an optical filter, an optical filter that transmits ultraviolet light in the wavelength band of 200 nm to 230 nm and does not substantially transmit ultraviolet light in the wavelength band of less than 200 nm in addition to ultraviolet light in the wavelength band of 240 nm to 300 nm is used. It doesn't matter. By substantially preventing the transmission of ultraviolet light in the wavelength band of less than 200 nm, the generation of ozone is suppressed, and the safety to the human body is further enhanced.

For example, a reflective member that reflects the light radiated by the light source may be arranged in the housing 2. By arranging the reflective member, the light from the light source toward the inner wall of the housing 2 is reduced, the light toward the extraction unit 4 is increased, and the illuminance of the light emitted from the ultraviolet light irradiation device 10 is increased.

As an example of the reflective member, the electrode block (9a, 9b) is formed with a material exhibiting reflectivity to ultraviolet light, or the electrode block (9a, 9b) itself is composed of a material exhibiting reflectivity to ultraviolet light. .. When the surface of the electrode block (9a, 9b) is reflective, the electrode block (9a, 9b) functions as a reflective member that directs ultraviolet light to the extraction portion 4. Further, a reflective member for directing more light to the extraction unit 4 may be provided separately from the electrode blocks (9a, 9b).

In the ultraviolet light irradiation device, the diffuser member 5 is shown to be in contact with the optical filter 6, but the diffuser member 5 may be arranged so as to be separated from the optical filter 6. Further, the diffusion member 5 or the optical filter 6 may be arranged not only in the opening of the housing 2 constituting the extraction portion 4 but also in the outer side of the housing 2.

Regarding the examples of the ultraviolet light irradiation device 10 shown in the above embodiment, the effect of expanding the light distribution angle by using the diffusing member was confirmed. The details of the ultraviolet light irradiation device 10 will be described later. FIG. 9 shows a measuring device 40 for measuring the light distribution angle of the ultraviolet light irradiation device. The measuring equipment 40 includes an ultraviolet light irradiation device 10, a rotating stage 30 for mounting the ultraviolet light irradiation device 10, and a luminometer 31. A UV POWER METOR C8026 manufactured by Hamamatsu Photonics Co., Ltd. is used for the illuminance meter 31.

The measuring equipment 40 includes a rotary stage 30, an ultraviolet light irradiation device 10 mounted on the rotary stage 30, and an illuminance meter 31 arranged at a distance d1: 300 (mm) from the ultraviolet light irradiation device 10. .. The position of the rotary stage 30 when the ultraviolet light irradiation device 10 is arranged facing the illuminance meter 31 is set to the initial position P0 so that the illuminance meter 31 is located on the optical axis L1 of the ultraviolet light irradiation device 10. The rotation stage 30 is rotated from the initial position P0 in the rotation direction R shown in FIG. In FIG. 9, the rotation stage 30 and the ultraviolet light irradiation device 10 at the initial position P0 are shown by dotted lines, and the rotation stage 30 and the ultraviolet light irradiation device 10 after being rotated in the rotation direction R for a predetermined time are shown by solid lines.

The angle θ4 formed between the optical axis L1 of the ultraviolet light irradiation device 10 and the light ray L3 incident on the luminometer 31 from the ultraviolet light irradiation device 10 represents the angle of rotation. The ultraviolet light irradiation device 10 increases the rotation angle θ4 from the initial position P0 where the rotation angle θ4 is 0 degrees (deg) (rotates the rotation stage 30) until the rotation angle θ4 reaches 80 degrees (deg). The illuminance was measured with the luminometer 31 while irradiating the ultraviolet light irradiation device.

In Example 1, the above-mentioned ultraviolet light irradiation device 10 from which the optical filter 6 was removed was used. In Comparative Example 1, the above-mentioned ultraviolet light irradiation device 10 from which the optical filter 6 and the diffusion member 5 were removed was used. There is no difference in the configuration of the ultraviolet light irradiation device 10 other than the presence / absence of the diffusion member 5 between the first embodiment and the first comparative example. In Example 2, the same device as the above-mentioned ultraviolet light irradiation device 10 was used. That is, the second embodiment has an optical filter 6 and a diffusion member 5. In Comparative Example 2, the above-mentioned ultraviolet light irradiation device 10 from which the diffusion member 5 was removed was used. The diffusion member 5 is a PTFE sheet having a thickness of 0.5 mm and having minute irregularities on the surface.

The relative illuminance was calculated based on the measured illuminance result. The relative illuminance is obtained by dividing the illuminance measurement value at an arbitrary rotation angle by the illuminance measurement value at a rotation angle of 0 degrees (deg). That is, the relative illuminance is a relative value of the illuminance of the light ray traveling at an arbitrary angle when the illuminance of the light ray traveling in the optical axis direction is 1. Graphs showing the relative illuminance with respect to the change in the angle of rotation are shown in FIGS. 10A and 10B.

With respect to the ultraviolet light irradiator without the optical filter 6, referring to FIG. 10A, Example 1 with the diffusing member 5 is higher relative to a wider angle range than Comparative Example 1 without the diffusing member 5. It shows the illuminance. Regarding the rotation angle at which the relative illuminance is 0.50 (measured illuminance that is half of the illuminance at the rotation angle of 0 degrees (optical axis)), Example 1 is larger by Δr1 (= about 4 degrees) than Comparative Example 1. .. Considering that the light distribution angle is obtained by twice the rotation angle at which the relative illuminance is 0.50, it can be said that the light distribution angle of Example 1 is expanded by about 8 degrees with respect to Comparative Example 1. .. From this, it can be seen that the light distribution angle is expanded by providing the diffusion member 5.

Regarding the ultraviolet light irradiation device having the optical filter 6, referring to FIG. 10B, Example 2 having the diffuser member 5 is higher relative to a wider angle range than Comparative Example 2 without the diffuser member 5. It shows the illuminance. Regarding the rotation angle at which the relative illuminance is 0.50, Example 2 has a larger Δr2 (= about 28 degrees) than Comparative Example 2. Considering that the light distribution angle is obtained by doubling the rotation angle at which the relative illuminance is 0.50, it can be said that the light distribution angle of Example 2 is expanded by about 56 degrees as compared with Comparative Example 2. .. From this, it can be seen that the light distribution angle is expanded by providing the diffusion member 5. Further, when comparing Example 1 and Example 2, it can be seen that this expansion of the light distribution angle is particularly remarkable when the optical filter 6 is provided.

2: Housing 2a: First frame (of housing) 2b: Second frame (of housing) 3: Excimer lamp 4: Extraction unit 5: Diffusing member 6: Optical filters 7a, 7b: Feed line 8a, 8b: Connection terminals 9a, 9b: Electrode block 10: Ultraviolet light irradiation device 30: Rotating stage 31: Luminometer 40: Measuring equipment

Claims (6)

A light source that emits ultraviolet light whose main emission wavelength is 190 nm to 235 nm,
A housing that houses the light source and
An extraction unit that takes out the ultraviolet light radiated from the light source to the outside of the housing, and
The diffusing member that diffuses the ultraviolet light and
An ultraviolet light irradiation device for inactivating microorganisms, which comprises. The ultraviolet light irradiation apparatus according to claim 1, further comprising an optical filter that transmits ultraviolet light in the wavelength band of 190 nm to 230 nm and substantially does not transmit ultraviolet light in the wavelength band of 240 nm to 300 nm. The optical filter and the diffusion member are arranged in the take-out portion, and the optical filter and the diffusion member are arranged in the take-out portion.
The ultraviolet light irradiation device according to claim 2, wherein the optical filter is located between the light source and the diffusion member. The ultraviolet light irradiation device according to any one of claims 1 to 3, further comprising a reflecting member that reflects light emitted from the light source in the housing. The ultraviolet light irradiation device according to any one of claims 1 to 4, wherein the diffusion member is made of a material mainly made of quartz glass, a fluororesin, polyethylene or PET. The ultraviolet light irradiation device according to any one of claims 1 to 5 is arranged so that at least a part of the emitted ultraviolet light is irradiated toward a manned space, and the ultraviolet light irradiation device is provided with the ultraviolet light. How to use an ultraviolet light irradiation device that irradiates light.

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