Light source device and inactivation device

Abstract

To provide a light source device and an inactivation device which are capable of inactivating bacteria and viruses without adversely affecting the human body even when an irradiation object in which many proteins are present is irradiated with ultraviolet light.SOLUTION: A light source device comprises a light-emitting unit that emits ultraviolet light and an optical system that propagates light emitted from the light-emitting unit, wherein the light-emitting unit comprises a point light source that emits light within a range of 225 nm or more and 235 nm or less, and the optical system receives light emitted from the light-emitting unit, exhibits a peak wavelength within a range of 225 nm or more and 235 nm or less, and emits light in which ultraviolet light within a range of 240 nm or more and 280 nm or less is limited.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present invention relates to a light source device and an inactivation device. [Background technology]

[0002] DNA is known to have the highest absorption characteristics around a wavelength of 260 nm, and low-pressure mercury lamps have a high emission spectrum around a wavelength of 254 nm. Therefore, a sterilization technique using ultraviolet light emitted from a low-pressure mercury lamp has been widely known.

[0003] However, ultraviolet light in the wavelength band of 240 nm or more and 280 nm or less has a high risk of affecting the human body, and therefore in recent years, a method of inactivating bacteria and viruses using a KrCl excimer lamp that emits ultraviolet light in the wavelength band of 190 nm to 230 nm with a main peak wavelength of 222 nm, which has extremely little effect on the human body, has been widely used (for example, Patent Document 1).

[0004] The reason why ultraviolet light in the wavelength band of 190 nm to 230 nm, with a main peak wavelength of 222 nm, has an extremely low risk of affecting the human body is because the absorption coefficient of proteins is large. [Prior art documents] [Patent documents]

[0005] [Patent Document 1] Japanese Patent Application Publication No. 2023-66627 Summary of the Invention [Problem to be solved by the invention]

[0006] However, the absorption coefficient of ultraviolet light with a wavelength of 222 nm is too high for proteins, so even in blood and body fluids, which contain a high proportion of protein, it is absorbed by the surface, which poses a problem in that even small amounts of bacteria and viruses that have entered the body are easily inhibited from being inactivated.

[0007] In view of the above problems, the present invention aims to provide a light source device and an inactivation device that can inactivate bacteria and viruses without adversely affecting the human body, even when irradiating ultraviolet light onto an object to be irradiated that contains a large amount of protein. [Means for solving the problem]

[0008] A light source device according to the present invention includes a light emitting unit that emits ultraviolet light, and an optical system that propagates the light emitted from the light emitting unit, the light-emitting unit includes a point light source that emits light in a range of 225 nm to 235 nm, The optical system receives the light emitted from the light emitting unit and emits light that has a peak wavelength in the range of 225 nm to 235 nm, with ultraviolet light limited to the range of 240 nm to 280 nm.

[0009] With this configuration, when irradiating ultraviolet light toward the human body, for example, ultraviolet light with a wavelength of around 230 nm has a longer protein transmission length and a relatively higher protein transmittance than ultraviolet light with a wavelength of 222 nm, so even if protein components such as blood or body fluids are present on the surface of the object to be irradiated, the inactivation of bacteria and viruses is less likely to be hindered. Furthermore, the optical system can limit the emission of ultraviolet light within the range of 240 nm to 280 nm, which may have an adverse effect on the human body, among the ultraviolet light emitted from the light-emitting unit, so that no adverse effects on the human body are caused. In this specification, the term "point light source" refers to a light source having a cross section of 5 mm or less in diameter relative to the optical axis in the light emission direction. For example, in the case of a discharge lamp having a pair of electrodes, this refers to a distance between the electrodes of 5 mm or less. In the case of a solid-state light source such as an LED or LD, this refers to a cross section of the chip light-emitting portion having a diameter of 5 mm or less. In the case of a laser light source other than a solid-state light source, this refers to a light-emitting cross section of the emission surface that emits ultraviolet light of 225 nm or more and 235 nm or less having a diameter of 5 mm or less. In addition, when a wavelength conversion element is used to emit ultraviolet light of 225 nm or more and 235 nm or less, this refers to a light-emitting cross section of the emission surface having a diameter of 5 mm or less. In addition, in this specification, "limiting ultraviolet light within the range of 240 nm or more and 280 nm or less" refers to a state in which the integrated intensity in the wavelength band of 240 nm or more and 300 nm or less is 5% or less of the integrated intensity in the wavelength band of 215 nm or more and 235 nm or less. In addition, in this specification, "inactivation" refers to a comprehensive concept of killing bacteria or viruses or eliminating their infectivity or toxicity, and "bacteria" refers to microorganisms such as bacteria and fungi (mold).

[0010] In the light source device, the optical system includes a light control mechanism; The light control mechanism may be configured to limit ultraviolet light within the range of 240 nm or more and 280 nm or less among the light emitted from the light emitting unit, and control the light to have a peak wavelength within the range of 225 nm or more and 235 nm or less.

[0011] According to this configuration, even if the light emitted from the light-emitting unit contains harmful light in the range of 240 nm or more and 280 nm or less, or does not have a peak wavelength in the range of 225 nm or more and 235 nm or less, the light control mechanism transmits or reflects specific wavelength bands, restricting light of any wavelength component from propagating within the optical system, thereby making it possible to control the light emitted from the optical system to have a desired optical spectrum.

[0012] In the light source device, the light control mechanism includes a plurality of light control units each including an optical filter that transmits ultraviolet light having a wavelength in the range of 225 nm to 235 nm, The configuration may also be such that, using a plurality of the light control units, the light emitted from the light emitting unit is limited to radiation within the range of 240 nm or more and 280 nm or less, and the light is controlled to have a peak wavelength within the range of 225 nm or more and 235 nm or less.

[0013] This configuration can more effectively limit the emission of harmful light in the range of 240 nm to 280 nm. For example, when an optical filter is used as the light control unit, even a simple optical filter that can reduce harmful light to about 10% can limit the transmission of harmful light to 1% by combining two of them. If a single optical filter is used to limit transmission to 1%, the manufacturing process may be difficult and the durability of the light control unit may be reduced. For these reasons, it is desirable to use multiple light control units to emit light in the desired wavelength band.

[0014] In addition, in the light source device, the light control mechanism may include a plurality of light control sections each made of a reflective filter that reflects ultraviolet light within a wavelength range of 225 nm to 235 nm, and the plurality of light control sections may be used to limit radiation within a range of 240 nm to 280 nm of the light emitted from the light emitting section, thereby controlling the light to have a peak wavelength within a range of 225 nm to 235 nm. With this configuration, even simple reflective filters that only slightly reflect harmful light can be used in combination to transmit only light of a desired wavelength band.

[0015] In the light source device, the light control mechanism may be configured to limit the emission of ultraviolet light of 215 nm or less emitted from the light emitting portion.

[0016] In this specification, "limiting the emission of ultraviolet light of 215 nm or less" refers to a state in which the integrated intensity in the wavelength band of 215 nm or less is 5% or less of the integrated intensity in the wavelength band of 215 nm or more and 235 nm or less.

[0017] According to this configuration, it is possible to remove ultraviolet light in the short wavelength band of 215 nm or less, which is relatively likely to contribute to the generation of ozone, from the light emitted from the light emitting section.

[0018] In the light source device, the light emitting unit is a discharge lamp, The discharge lamp is a fuselage having a recess formed therein that opens forward; a reflecting surface formed on a surface of the recess; a light-transmitting window member that closes the opening of the body; a discharge space surrounded by the body and the window member and filled with a discharge gas; The light source may further comprise a pair of electrodes disposed opposite each other in the discharge space so as to sandwich a focal position of the reflecting surface therebetween.

[0019] By using a discharge lamp as the light emitting section, it is possible to emit a large amount of light.

[0020] In the light source device, the light emitting unit includes an LED, The light emitted from the LED may have a peak emission wavelength in the range of 225 nm to 235 nm, with radiation being restricted to the range of 240 nm to 280 nm.

[0021] With this configuration, light in the range of 240 nm or more and 280 nm or less is not emitted from the light-emitting unit, so there is no need to provide a separate light control mechanism downstream of the light-emitting unit to restrict light in the range of 240 nm or more and 280 nm or less.

[0022] In the light source device, the light emitting section may be configured not to emit ultraviolet light of 215 nm or less.

[0023] According to this configuration, there is no need to provide a separate light control mechanism downstream of the light emitting section for limiting the emission of ultraviolet light of 215 nm or less emitted from the light emitting section.

[0024] In the light source device, the light emitting unit or the optical system is The optical element may be configured to collimate the light from the point light source.

[0025] According to this configuration, by collimating the light from the point light source, it is easy to concentrate the light on the irradiation surface even when the light propagates through a plurality of other optical members (lenses, reflecting surfaces, etc.).

[0026] In the light source device, the optical system includes an optical lens that condenses the light emitted from the light emitting unit; The optical fiber may further include a light guide member that propagates light from the optical lens from one end to the other end.

[0027] According to this configuration, by propagating the light emitted from the light-emitting unit from one end to the other end of the light-guiding member, it becomes easier to provide ultraviolet light belonging to the wavelength band of 225 nm or more and 235 nm or less to the surface of the object to be irradiated (for example, a narrow area or the surface of an area inside the human body or an object) that is difficult for light to reach.

[0028] In the light source device, the light control mechanism may be configured to include a light control unit consisting of a reflective filter that reflects ultraviolet light in a wavelength band of 225 nm or more and 235 nm or less that is emitted from the light-emitting unit, and transmits light in a range of 240 nm or more and 3000 nm or less that is emitted from the light-emitting unit.

[0029] According to this configuration, the light emitted from the optical system can be controlled to a desired optical spectrum by limiting the emission of ultraviolet light in the range of 240 nm to 280 nm, which may have an effect on the human body, or by limiting the emission of undesired light components (excess visible light and infrared light) in the range of 400 nm to 3000 nm.

[0030] An inactivation device according to the present invention includes the light source device described above, which irradiates the light emitted from the optical system toward the surface of the human body or the inside of the human body.

[0031] This configuration makes it possible to inactivate bacteria and viruses without adversely affecting the human body.

[0032] In the inactivation device, the optical system includes an optical lens that condenses the light emitted from the light-emitting unit; The optical fiber may further include a light guide member that propagates light from the optical lens from one end to the other end.

[0033] According to this configuration, the light with high illuminance collected by the optical lens can be irradiated to any desired location by the light guide member.

[0034] In the inactivation device, the other end of the light-guiding member may have an internal insertion portion that is inserted into the human body.

[0035] According to this configuration, the light emitted from the optical system can be directly irradiated onto the inside of the human body. [Brief explanation of the drawings]

[0036] [Figure 1] 1 is a schematic diagram showing an example of the configuration of a light source device and an inactivation device according to the present embodiment; [Figure 2] UV absorption spectrum of proteins [Figure 3] Protein transmission length versus wavelength [Figure 4] Protein transmittance for wavelength [Figure 5] Spectra of the light source device of this embodiment and a conventional light source device [Figure 6] DNA absorption coefficient vs. wavelength [Figure 7] Illuminance for the irradiation distance of the light source device of this embodiment and the time required to kill 99% of Staphylococcus aureus [Figure 8] Illuminance at irradiation distance of conventional light source devices and time required to kill 99% of Staphylococcus aureus [Figure 9] Schematic diagram showing the configuration of a light source device and an inactivation device according to another embodiment. [Figure 10] Schematic diagram showing the configuration of a light source device and an inactivation device according to another embodiment. [Figure 11] Schematic diagram showing the configuration of a light source device according to another embodiment. [Figure 12] Schematic diagram showing the configuration of a light source device according to another embodiment. [Figure 13] Schematic diagram showing the configuration of a light source device according to another embodiment. [Figure 14]Schematic diagram showing the configuration of a light source device according to another embodiment. [Figure 15] Schematic diagram showing the configuration of a light source device according to another embodiment. [Figure 16] 1 is a front view of an endoscope to which an inactivation device is applied; DETAILED DESCRIPTION OF THE INVENTION

[0037] The following description will discuss embodiments of a light source device and an inactivation device according to the present invention with reference to the drawings. Note that the drawings are schematic illustrations, and the dimensional ratios in the drawings do not necessarily correspond to the actual dimensional ratios, and the dimensional ratios between the drawings do not necessarily correspond to the actual dimensional ratios.

[0038] FIG. 1 is a schematic diagram showing an example of the configuration of an embodiment of a light source device and an inactivation device. As shown in FIG. 1, the light source device 1 includes a light-emitting unit 2 that emits ultraviolet light and an optical system 2a that propagates the light emitted from the light-emitting unit 2. The optical system 2a may include a light control mechanism 3. The light control mechanism 3 may also include optical filters 31 and 32 and a reflection filter 34 as a light control unit. The optical system 2a may also include an optical lens 5 and an optical fiber 6 (an example of a light-guiding member). The inactivation device 9 includes the light source device 1.

[0039] The light emitting unit 2 includes a point light source 20 that emits light in the range of 225 nm to 235 nm.

[0040] As an example, we conducted experiments on the ultraviolet absorption spectrum of a 27% aqueous solution of bovine serum albumin, a type of protein, the transmission length when the light intensity is 1 / 10 of the wavelength, and the transmittance at a thickness of 1 μm. The results are shown in Figures 2 to 4, respectively. As shown in FIG. 2, ultraviolet light with a wavelength of 230 nm has a smaller absorption coefficient for proteins than ultraviolet light with a wavelength of 222 nm, and is therefore less easily absorbed. Furthermore, as shown in Figure 3, the wavelength of 230 nm has a longer transmission length than the wavelength of 222 nm, allowing light to penetrate deeper into the protein layer. Furthermore, as shown in FIG. 4, the wavelength of 230 nm has a higher transmittance than the wavelength of 222 nm. Based on the relationship between the transmission length in Figure 3 and the transmittance in Figure 4, 230 nm UV light has a longer protein transmission length and higher protein transmittance than 222 nm UV light. Therefore, 230 nm UV light can more easily reach bacteria and viruses on the surface of areas with blood or body fluids, which 222 nm UV light has difficulty reaching, and can more effectively inactivate bacteria and viruses.

[0041] The light-emitting unit 2 of this embodiment is a discharge lamp. The light-emitting unit 2 includes a body 21 having a recessed portion that opens forward, a reflecting surface 22 formed on the surface of the recessed portion, a light-transmitting window member 23 that closes the opening of the body 21, a discharge space 24 surrounded by the body 21 and the window member 23, and a pair of electrodes 25 and 26 that are arranged opposite each other in the discharge space 24 and sandwich the focal position of the reflecting surface 22. The point light source 20 is composed of the discharge space 24 and the pair of electrodes 25 and 26.

[0042] The body 21 is made of ceramics such as alumina from the viewpoint of insulation, heat resistance, pressure resistance, and the like.

[0043] The reflecting surface 22 is formed on the surface of the recess of the body 21. The reflecting surface 22 reflects light emitted between the pair of electrodes 25, 26 and outputs it as parallel light L1. The reflecting surface 22 can also be said to be an optical member that collimates the light from the point light source 20. The reflecting surface 22 is made of, for example, a metal vapor deposition film made of aluminum or the like or a dielectric multilayer film.

[0044] Hereinafter, the traveling direction of the parallel light L1 emitted from the reflecting surface 22 is referred to as the X direction, and the plane perpendicular to the X direction is referred to as the YZ plane. In this specification, when a direction is expressed and a distinction is made between positive and negative directions, it is written with a positive or negative sign, such as "+X direction" and "-X direction." When a direction is expressed without distinguishing between positive and negative directions, it is simply written as "X direction." In other words, in this specification, when simply written as "X direction," it includes both the "+X direction" and the "-X direction." The same applies to the Y direction and the Z direction.

[0045] The window member 23 has, for example, a disk shape. The window member 23 is arranged along the YZ plane. The parallel light L1 emitted from the reflecting surface 22 is emitted to the outside from the window member 23. The window member 23 is made of a light-transmitting material such as sapphire or quartz glass.

[0046] The discharge space 24 is a space surrounded by the body 21 and the window member 23, and is filled with a discharge gas such as mercury or xenon gas. That is, the point light source 20 is, for example, a high-pressure mercury lamp or a xenon lamp.

[0047] The pair of electrodes 25, 26 includes, for example, an anode 25 and a cathode 26. When a predetermined voltage is applied between the pair of electrodes 25, 26, an arc discharge is formed between the pair of electrodes 25, 26, generating plasma. The generated plasma excites the discharge gas, causing it to emit light such as ultraviolet light with a wavelength of around 230 nm, ultraviolet light in the UVC band between 240 nm and 280 nm, visible light, and infrared light. The distance between the pair of electrodes 25, 26 is preferably 5 mm or less, and more preferably 3 mm or less. The point light source 20 is a light source that emits light that diverges from a single point. By including the point light source 20 in the light-emitting unit 2, high illuminance can be achieved on the irradiated surface by re-condensing the light emitted from the point light source 20 via the optical system 2a.

[0048] The light control mechanism 3 includes a first light control section 31. The first light control section 31 is disposed in front of (on the +X side of) the window member 23 and spaced apart from the window member 23. The first light control section 31 is disposed, for example, 2 to 3 cm away from the window member 23.

[0049] The first light control unit 31 limits the emission of ultraviolet light within the range of 240 nm or more and 280 nm or less, which is emitted from the light-emitting unit 2. In this way, the first light control unit 31 can remove ultraviolet light within the range of 240 nm or more and 280 nm or less, which may have an adverse effect on the human body, from the light emitted from the light-emitting unit 2.

[0050] Furthermore, the first light control unit 31 may limit the emission of ultraviolet light of 215 nm or less emitted from the light-emitting unit 2. This allows the first light control unit 31 to remove ultraviolet light in the short wavelength band of 215 nm or less, which is relatively likely to contribute to the generation of ozone, from the light emitted from the light-emitting unit 2.

[0051] Furthermore, the first light control section 31 may be configured to limit the emission of ultraviolet light in the UVA band, which is on the wavelength side longer than 320 nm.

[0052] The first light control unit 31 may be configured with an optical filter that cuts out harmful light, as in this embodiment. The first light control unit 31 is typically configured with a plate-shaped filter. In this embodiment, the first light control unit 31 and the second light control unit 32 are configured by stacking two optical filters. Note that the optical filter may be configured by stacking three or more optical filters. Alternatively, the first light control unit 31 may use a reflective filter to limit the emission of harmful light in the range of 240 nm to 280 nm, or may include multiple light control units that use both optical filters and reflective filters.

[0053] The optical filter is composed of a dielectric multilayer film in which multiple layers with different refractive indices are stacked. Examples of dielectric multilayer films include those in which HfO2 layers and SiO2 layers are alternately stacked. The optical filter suppresses transmission of ultraviolet light of 240 nm or longer. The optical filter of this embodiment transmits ultraviolet light in the range of at least 225 nm to 235 nm, while reflecting ultraviolet light in the wavelength range of 240 nm or longer that is harmful to the human body. For example, the optical filter preferably has a transmittance of 10% or less, more preferably 5% or less, and even more preferably 1% or less, of ultraviolet light in the wavelength range of 240 nm to 280 nm emitted from the light-emitting unit 2 when the ultraviolet light is perpendicularly incident on the filter surface. The optical filter may also limit transmission of ultraviolet light in the wavelength range of 240 nm to 300 nm, or may limit transmission of ultraviolet light in the wavelength range of 240 nm to 320 nm, of ultraviolet light emitted from the light-emitting unit 2. Although the above assumes that an optical filter is used as the light control unit, a reflective filter that reflects at least ultraviolet light in the range of 225 nm to 235 nm while transmitting ultraviolet light in the wavelength range of 240 nm or more that is harmful to the human body may be used to limit the propagation of ultraviolet light in the harmful wavelength range within the optical system. Of course, with regard to wavelengths that are not emitted from the light-emitting unit 2, there is no need to limit the transmission or reflection of light in those wavelength components.

[0054] The optical filter also functions to absorb ultraviolet light in the wavelength range of 215 nm or less, which is relatively likely to contribute to ozone generation. This is because the HfO2 layer absorbs ultraviolet light in the wavelength range of 215 nm or less. Therefore, by increasing the total number of HfO2 layers through which the light emitted from the light-emitting unit 2 passes during propagation within the optical system 2a, ultraviolet light in the wavelength range of 215 nm or less can be limited to a desired range.

[0055] Furthermore, a reflective filter 34 may be disposed separately from the first light control section. The reflective filter 34 is disposed so as to receive the light emitted from the window member 23. In this embodiment, the reflective filter 34 receives the collimated light L1 emitted from the window member 23 via the first light control section 31. That is, the collimated light L2 received by the reflective filter 34 is light obtained by the first light control section 31 restricting ultraviolet light in the range of 240 nm to 280 nm from the collimated light L1 and removing ultraviolet light in the wavelength range of 215 nm or less.

[0056] The reflective filter 34 reflects ultraviolet light in the wavelength range of 225 nm to 235 nm and transmits light in the range of 240 nm to 3000 nm. As a result, the collimated light L3 reflected by the reflective filter 34 includes ultraviolet light exhibiting a light intensity in at least the wavelength range of 225 nm to 235 nm and can remove any wavelength component in the range of 240 nm to 3000 nm. For example, the reflective filter 34 may reflect ultraviolet light in the wavelength range of 225 nm to 235 nm from the ultraviolet light emitted from the light-emitting unit and transmit ultraviolet light in the wavelength range of 240 nm to 280 nm that may be harmful to the human body, thereby removing the wavelength component. Alternatively, the reflective filter 34 may transmit undesired light components in the range of 400 nm to 3000 nm, thereby removing the wavelength component. This is particularly useful for removing light components with high light intensity in the range of 400 nm to 3000 nm. As described above, by using the reflective filter 34, it is possible to control the light emitted from the optical system to have a desired optical spectrum.

[0057] The reflection filter 34 of this embodiment is a plate-shaped filter having a reflection surface 34a made of a dielectric multilayer film, and is disposed so that the reflection surface 34a is inclined at 45 degrees with respect to the YZ plane. The reflection filter 34 is not limited to a plate-shaped filter. The reflection filter 34 may be disposed so that the reflection surface 34a is inclined at an angle other than 45 degrees with respect to the YZ plane, or the angle of the reflection surface 34a with respect to the YZ plane may be adjustable. The reflection filter 34 may be integral with the first light control unit 31. The substrate constituting the reflection filter 34 preferably has a diffusing surface (e.g., a frosted surface) or an AR coating (anti-reflection coating) on ​​the substrate surface to prevent interfacial reflection at the substrate surface with respect to a surface other than the reflection surface 34a.

[0058] The optical lens 5 is disposed so as to receive the parallel light L3 reflected by the reflection filter 34. The optical lens 5 may be configured integrally with the reflection filter 34. The optical lens 5 condenses the parallel light L3. The light condensed by the optical lens 5 is incident on the optical fiber 6. Therefore, the optical lens 5 is disposed so that the focal point of the optical lens 5 is located at the center of the incident surface of the optical fiber 6.

[0059] The optical lens 5 may include at least one aspherical lens. The optical lens 5 is formed of, for example, quartz glass. The optical lens 5 preferably has a transmittance of 70% or more, more preferably 80% or more, for ultraviolet light with a wavelength of 230 nm. Furthermore, the optical lens 5 preferably has a refractive index ratio of 230 nm / 1000 nm of 1.04 or more, more preferably 1.05 or more. By using an optical lens 5 with large chromatic aberration, it is possible to cut infrared light incident on the optical fiber 6. Furthermore, the optical lens 5 preferably has an NA of 0.4 or less.

[0060] The optical fiber 6 is a fiber whose core is made of, for example, synthetic quartz or liquid. The optical fiber 6 propagates light from the optical lens 5 from one end to the other end. The optical fiber 6 preferably has an NA of 0.2 or more, more preferably 0.4 or more. The optical fiber 6 preferably has a core diameter of 10 mm or less, more preferably 5 mm or less. The light guided through the optical fiber 6 is irradiated onto the human body to inactivate bacteria and viruses.

[0061] Next, the light source device 1 of this embodiment shown in FIG. 1 will be compared with a conventional light source device. The conventional light source device uses a KrCl excimer lamp with a main peak wavelength of 222 nm in the light-emitting section, combined with an optical filter that blocks transmission of ultraviolet light between 240 nm and 280 nm. The excimer lamp is operated with a power of 10 W. The ultraviolet light emitted from the light-emitting section is irradiated onto the target surface via an optical system that includes an optical fiber. The optical fiber used here is φ5 mm, and the illuminance at the output end of the fiber is 10 to 15 mW / cm. 2 is adjusted to. The light source device 1 of the present application uses a ceramic xenon lamp that emits light over a wide wavelength range from 200 nm to 1000 nm as the light-emitting unit 2, and transmits the light emitted from the light-emitting unit 2 to an optical system 2a that includes an optical fiber 6. The optical system 2a is equipped with a light control mechanism 3 that transmits light in the wavelength range of 225 nm to 235 nm and restricts transmission of ultraviolet light in the wavelength range of 240 nm to 280 nm. A reflection filter 34 that reflects light in the wavelength range of 225 nm to 235 nm and transmits light in the wavelength range of 340 nm to 1000 nm is disposed downstream of the light control mechanism 3, and the light in the wavelength range of 225 nm to 235 nm that is transmitted from the reflection filter 34 is transmitted to the optical fiber 6. The optical fiber 6 used here has a diameter of 3 mm, and the illuminance at the fiber's output end face is 200 mW / cm. 2 is adjusted to.

[0062] FIG. 5 shows the spectra of light source device 1 of this embodiment and a conventional light source device. Graph A is the spectrum of light source device 1 of this embodiment, which has a peak at 230 nm, and graph B is the spectrum of the conventional light source device, which has a peak at 222 nm. As shown in FIG. 5, light source device 1 can emit ultraviolet light in the long wavelength range that was not primarily emitted by conventional light source devices. Furthermore, the emission of ultraviolet light of 215 nm or less, which was emitted by conventional light source devices, is further reduced.

[0063] Figure 6 shows the absorption coefficient of thymine, one of the bases that make up DNA. Hereafter, this graph will be referred to as the DNA absorption coefficient. As shown in Figure 6, the absorption rate of DNA at a wavelength of 230 nm is lower than that of 222 nm, so 230 nm ultraviolet light requires a greater dose of irradiation than 222 nm ultraviolet light. However, 222 nm ultraviolet light is less likely to reach bacteria and viruses on the surface of an object that has protein components such as blood or body fluids attached to it, making it easier for the light to reach these bacteria and viruses, effectively inactivating them. Furthermore, the light source device 1 of the present application can withstand higher power than conventional devices, and is capable of emitting high-intensity ultraviolet light by forming high-output plasma, thereby shortening the irradiation time required for inactivation.

[0064] FIG. 7 is a table showing the illuminance versus irradiation distance of the light source device 1 of this embodiment and the time required to sterilize 99% of Staphylococcus aureus. FIG. 8 is a table showing the illuminance versus irradiation distance of a conventional light source device and the time required to sterilize 99% of Staphylococcus aureus. Here, ultraviolet light with a wavelength of 230 nm has a lower DNA absorption rate than ultraviolet light with a wavelength of 222 nm, so the cumulative irradiation dose (15 mJ / cm) required to sterilize 99% of Staphylococcus aureus shown in FIG. 7 is 15 mJ / cm. 2 ) is the cumulative irradiation dose (10 mJ / cm ) shown in Figure 8 2 ) is assumed to require 1.5 times the amount of irradiation.

[0065] As shown in FIGS. 7 and 8, when 99% of Staphylococcus aureus is sterilized at an irradiation distance of 200 mm, the illuminance of the light source device 1 of this embodiment is 0.033 mW / cm 2 The cumulative light intensity is 15mJ / cm 2 The irradiation time required to reach this level was 7.6 min, and the illuminance of the conventional light source was 0.006 mW / cm 2 The cumulative light intensity is 10 mJ / cm 2 The irradiation time required to reach this level is 29.7 minutes, which is a significant reduction of 1 / 3.9.

[0066] As described above, the light source device 1, as in this embodiment, preferably comprises a light-emitting unit 2 that emits ultraviolet light and an optical system 2a that propagates the light emitted from the light-emitting unit 2, wherein the light-emitting unit 2 comprises a point light source 20 that emits light in the range of 225 nm to 235 nm, and the optical system 2a receives the light emitted from the light-emitting unit 2 and emits light that exhibits a peak wavelength in the range of 225 nm to 235 nm and has ultraviolet light limited to the range of 240 nm to 280 nm.

[0067] Furthermore, in the light source device 1 of this embodiment, the optical system 2a is preferably equipped with a light control mechanism 3, and the light control mechanism 3 is preferably configured to restrict ultraviolet light within the range of 240 nm or more and 280 nm or less from the light emitted from the light-emitting unit 2, and to control the light to have a peak wavelength within the range of 225 nm or more and 235 nm or less.

[0068] According to this configuration, ultraviolet light with a wavelength of around 230 nm emitted from the light-emitting unit 2 (point light source 20) has a longer transmission length through proteins and a relatively higher protein transmittance than ultraviolet light with a wavelength of 222 nm. Therefore, it is more suitable for inactivating bacteria and viruses in irradiation targets containing many proteins, such as the surface of the human body (especially surgical sites requiring sterilization) and inside the human body. It is also suitable for inactivating bacteria and viruses contained in blood, body fluids, and other proteins. Furthermore, the optical system 2a can limit the emission of ultraviolet light with a wavelength of 240 nm or more and 280 nm or less, which may be harmful to the human body, among the ultraviolet light emitted from the light-emitting unit 2, thereby preventing adverse effects on the human body. Furthermore, since the light-emitting unit 2 includes the point light source 20, high illuminance can be achieved on the irradiation surface by re-condensing the light emitted from the point light source 20 via the optical system.

[0069] The light source device 1 is useful not only when irradiating the light emitted from the optical system 2a onto the surface or interior of the human body, but also when irradiating ultraviolet light onto an object to be irradiated that contains a large amount of protein (for example, food, general objects soiled with food (tables, etc.), etc.).

[0070] Furthermore, in the light source device 1 of this embodiment, the light control mechanism 3 is preferably configured to limit the emission of ultraviolet light of 215 nm or less emitted from the light emitting section 2.

[0071] Furthermore, the light source device 1 of this embodiment is configured so that light from the point light source 20 is emitted via an optical element (in this embodiment, a reflective surface 22). Furthermore, in the light source device 1, as in this embodiment, it is preferable that the optical element (in this embodiment, a reflective surface 22) collimates the light from the point light source 20. By collimating the light from the point light source 20, it is easy to concentrate the light on the irradiation surface even when the light propagates via multiple other optical elements. This makes it possible to illuminate a narrow area with higher illuminance. Furthermore, by collimating the light from the point light source 20, it is possible to increase the light component that is perpendicularly incident on the optical filter, so that the light component that passes through the optical filter is less likely to be attenuated.

[0072] Furthermore, in the light source device 1 of this embodiment, the light-emitting section 2 is a discharge lamp, and the discharge lamp preferably comprises a body 21 having a recess that opens forward, a reflective surface 22 formed on the surface of the recess, a light-transmitting window member 23 that closes the opening of the body 21, a discharge space 24 surrounded by the body 21 and the window member 23 and filled with discharge gas, and a pair of electrodes 25, 26 arranged opposite each other in the discharge space 24 so as to sandwich the focal position of the reflective surface 22.

[0073] Furthermore, in the light source device 1 of this embodiment, the first light control section 31 and the second light control section 32 are preferably configured as optical filters that suppress transmission of ultraviolet light in the range of 240 nm to 300 nm.

[0074] Furthermore, in the light source device 1 of this embodiment, it is preferable that the first light control section 31 and the second light control section 32 are optical filters arranged at a distance from the window member 23.

[0075] Furthermore, in the light source device 1 of this embodiment, it is preferable that the first light control section 31 and the second light control section 32 are configured to limit the emission of ultraviolet light of 215 nm or less emitted from the light-emitting section 2. With this configuration, it is possible to remove ultraviolet light in the short wavelength band of 215 nm or less, which is relatively likely to contribute to the generation of ozone, from the light emitted from the light-emitting section 2.

[0076] Furthermore, in the light source device 1 of this embodiment, it is preferable that the light control mechanism 3 further includes a reflective filter 34 that reflects ultraviolet light in the wavelength band of 225 nm or more and 235 nm or less that is emitted from the light-emitting unit 2, and transmits light in the range of 240 nm or more and 3000 nm or less that is emitted from the light-emitting unit 2. With this configuration, it is possible to further limit the emission of ultraviolet light of 240 nm or more that may have an effect on the human body, among the ultraviolet light emitted from the light-emitting unit 2, and / or to limit the emission of excessive visible light, and / or to limit the emission of excessive infrared light that becomes heat rays, and to emit light from the optical system.

[0077] The inactivation device 9 of this embodiment is configured to include a light source device 1 that irradiates light emitted from an optical system 2a onto the surface of the human body or the inside of the human body. For example, the inactivation device 9 according to the present invention can be applied in situations where sterilization is required in a surgical site, the oral cavity, or the like.

[0078] Although the embodiments of the present invention have been described above with reference to the drawings, the specific configurations should not be considered to be limited to these embodiments. The scope of the present invention is defined not only by the description of the above embodiments but also by the claims, and further includes all modifications within the meaning and scope of the claims.

[0079] The structures employed in the above-described embodiments can be employed in any other embodiment. The specific configurations of the components are not limited to the above-described embodiments, and various modifications are possible within the scope of the present invention.

[0080] (1) In the light source device 1 according to the above embodiment, the first light control unit 31 (optical filter) is configured to limit the emission of ultraviolet light of 215 nm or less emitted from the light-emitting unit 2. However, the light source device 1 is not limited to this configuration. For example, as shown in FIG. 9, the light source device 1 may further include a third light control unit 33 that controls the light emitted from the light-emitting unit 2, and the third light control unit 33 may limit the emission of ultraviolet light of 215 nm or less emitted from the light-emitting unit 2. That is, the third light control unit 33, which is different from the first light control unit 31, may limit the emission of ultraviolet light of 215 nm or less emitted from the light-emitting unit 2. The third light control unit 33 may be configured to include an optical filter that suppresses the transmission of ultraviolet light of 200 nm to 215 nm. Alternatively, the third light control unit 33 may be an optical filter provided on the outer surface of the window member 23. The third light control section 33 is, for example, a single layer film of HfO2, a single layer film of Y2O3, or a dielectric multilayer film formed by laminating one of these with SiO2. Although not shown, the third light control section 33 may be an optical filter arranged at a distance from the window member 23, similar to the first light control section 31.

[0081] (2) In the light source device 1 according to the above embodiment, the first light control unit 31 is configured as an optical filter disposed at a distance from the window member 23. However, the light source device 1 is not limited to this configuration. As shown in FIG. 10 , the first light control unit 31 may be configured as an optical filter provided on the outer surface of the window member 23 of the light-emitting unit 2. In this case, the optical filter serving as the first light control unit 31 may be vapor-deposited on the front surface of the window member 23.

[0082] (3) In the light source device 1 according to the above embodiment, the light-emitting unit 2 is a discharge lamp. However, the light source device 1 is not limited to this configuration. As shown in FIG. 11 , the light-emitting unit 2 may be equipped with an LED, and the light emitted from the LED may have an emission peak wavelength in the range of 225 nm to 235 nm, with radiation in the range of 240 nm to 280 nm being restricted. It is also preferable that the light-emitting unit 2 does not emit ultraviolet light of 215 nm or less. In this case, the point light source 20 is an LED chip, and the LED chip has a diameter of 5 mm or less. The light from the point light source 20 is collimated by an optical lens 7.

[0083] As shown in FIG. 12, the first light control section 31 may be an optical filter provided on the outer surface of the window member of the LED.

[0084] Furthermore, as shown in FIG. 13, the light source device 1 does not necessarily have to include the reflection filter .

[0085] Furthermore, as shown in FIG. 14, the light source device 1 does not need to collimate the light from the point light source 20. 15, the light-emitting unit 2 may include a plurality of point light sources 20. In this example, the point light sources 20 are LED chips. The light emitted from the plurality of point light sources 20 is collimated by a collimating lens 8, respectively.

[0086] (4) Furthermore, the light source device 1 may not include the optical lens 5 and the optical fiber 6 as shown in FIG. 1. In this case, the light source device 1 may irradiate the parallel light L3 reflected by the reflection filter 34 directly onto the irradiation surface (for example, the surface of the human body). Furthermore, the light source device 1 may include the optical lens 5 but not the optical fiber 6. In this case, the light source device 1 may irradiate the light focused by the optical lens 5 onto the irradiation surface (for example, the surface or the inside of the human body).

[0087] (5) FIG. 16 is a front view of an endoscope to which an inactivation device is applied. The endoscope includes an optical endoscope 91 (an example of an inactivation device 9). The endoscope also includes a light-emitting unit (not shown) that emits ultraviolet light and an optical system that propagates the light emitted from the light-emitting unit. The optical system includes an optical lens (not shown) that focuses the light emitted from the light-emitting unit and a light guide cable 91a (an example of a light-guiding member) that propagates the light from the optical lens from one end to the other end. The other end of the light guide cable 91a has an internal insertion section 91b that is inserted into the human body. The light propagated through the light guide cable 91a is propagated by the internal insertion section 91b to a distal end 91c of the insertion section and emitted. This allows the light emitted from the optical system to be irradiated toward the inside of the human body. For example, in arthroscopic surgery, a hole of a few millimeters is drilled into the surgical site, and the joint and surgical instruments are inserted into the human body. In this case, the area to be sterilized is the entire interior of the surgical site, from the hole on the surface of the human body to the tip of the surgical instruments. If an endoscope such as that shown in Figure 16 is used, ultraviolet light can be irradiated onto the inner wall surface of the insertion part of the surgical instruments when inserted into the body, and ultraviolet light can also be irradiated from the tip 91c of the insertion part onto the area where the surgical instruments will be used for resection, etc. The invention is not limited to an endoscope, and may be used in a form in which an internal insertion portion inserted into the oral cavity is used for sterilizing the inside of the mouth. [Explanation of symbols]

[0088] 1:Light source device 2: Light-emitting part 2a:Optical system 3: Light control mechanism 5: Optical lens 6: Optical fiber 7: Optical lens 8: Collimating lens 9:Inactivation device 20: Point light source 21: Torso 22: Reflective surface 23: Window material 24:Discharge space 25:Anode 26 :Cathode 31: First light control unit 32: Second light control unit 33: Third light control unit 34: Reflection filter 34a: Reflective surface 91: Optical viewing tube 91a: Light guide cable 91b: Internal insertion part 91c: Insertion tip L1:Parallel light L2:Parallel light L3: Parallel light

Claims

1. a light-emitting unit that emits ultraviolet light; and an optical system that propagates the light emitted from the light-emitting unit; the light-emitting unit includes a point light source that emits light in a range of 225 nm to 235 nm, The optical system receives light emitted from the light-emitting unit and emits light that has a peak wavelength in the range of 225 nm or more and 235 nm or less, with ultraviolet light limited to the range of 240 nm or more and 280 nm or less.

2. the optical system includes a light control mechanism; 2. The light source device according to claim 1, wherein the light control mechanism limits ultraviolet light within a range of 240 nm or more and 280 nm or less from the light emitted from the light-emitting unit, and controls the light to have a peak wavelength within a range of 225 nm or more and 235 nm or less.

3. the light control mechanism includes a plurality of light control units each including an optical filter that transmits ultraviolet light having a wavelength in the range of 225 nm to 235 nm, 3. The light source device according to claim 2, wherein a plurality of the light control units are used to limit radiation within the range of 240 nm or more and 280 nm or less of the light emitted from the light emitting unit, and control the light to have a peak wavelength within the range of 225 nm or more and 235 nm or less.

4. 3. The light source device according to claim 2, wherein the light control mechanism limits the emission of ultraviolet light of 215 nm or less emitted from the light emitting portion.

5. the light-emitting unit is a discharge lamp, The discharge lamp is a fuselage having a recess formed therein that opens forward; a reflecting surface formed on a surface of the recess; a light-transmitting window member that closes the opening of the body; a discharge space surrounded by the body and the window member and filled with a discharge gas; 3. The light source device according to claim 2, further comprising: a pair of electrodes disposed opposite each other in the discharge space so as to sandwich a focal position of the reflecting surface therebetween.

6. the light-emitting unit includes an LED, 2. The light source device according to claim 1, wherein the light emitted from the LED has an emission peak wavelength in the range of 225 nm to 235 nm, and radiation in the range of 240 nm to 280 nm is restricted.

7. 7. The light source device according to claim 6, wherein the light emitting section does not emit ultraviolet light of 215 nm or less.

8. The light emitting unit or the optical system is 8. The light source device according to claim 1, further comprising an optical member for collimating the light from the point light source.

9. The optical system includes an optical lens that collects light emitted from the light emitting unit; 8. The light source device according to claim 1, further comprising a light guide member that propagates the light from the optical lens from one end to the other end.

10. The light source device according to any one of claims 1 to 7, characterized in that the light control mechanism includes a light control unit consisting of a reflective filter that reflects ultraviolet light in the wavelength band of 225 nm or more and 235 nm or less emitted from the light-emitting unit, and transmits light in the range of 240 nm or more and 3000 nm or less emitted from the light-emitting unit.

11. An inactivation device comprising the light source device according to any one of claims 1 to 7, which irradiates light emitted from the optical system toward the surface of the human body or the interior of the human body.

12. The optical system includes an optical lens that collects light emitted from the light emitting unit; 12. The inactivation device according to claim 11, further comprising a light guide member that propagates light from the optical lens from one end to the other end.

13. 13. The inactivation device according to claim 12, wherein the other end of the light-guiding member has an internal insertion portion that is inserted into the human body.

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