CN114569771A - Inactivation device and inactivation method - Google Patents

Abstract

Inactivation of microorganisms and/or viruses using ultraviolet rays in a wavelength range that suppresses adverse effects on the human body can be performed efficiently and more appropriately. The inactivation device includes: a light source unit that radiates ultraviolet rays having a center wavelength in a wavelength band of 190 nm to 235 nm; a sensing unit that senses whether a person exists in the target space; and a control unit that controls the lighting state of the light source unit . The control unit controls by including a first lighting operation performed during a period when the sensing unit senses the presence of a person and a second lighting operation performed during a period when the sensing unit does not sense the presence of a person, The amount of ultraviolet rays emitted from the light source unit is changed, and the average illuminance of ultraviolet rays in the first lighting operation is controlled to be lower than the average illuminance of ultraviolet rays in the second lighting operation.

Description

Inactivation device and inactivation method

technical field

The present invention relates to an inactivation device and an inactivation method for inactivating harmful microorganisms and viruses.

Background technique

Conventionally, in order to prevent the spread of infectious diseases caused by harmful microorganisms (bacteria, mold, etc.) and viruses, the following operations have been performed: Microbes and viruses in various places are irradiated with ultraviolet rays to inactivate them.

For example, Patent Document 1 discloses an indoor sterilization device which is installed in the upper part of the room and irradiates ultraviolet rays in the horizontal direction, diagonally downward, and downward of the room.

The indoor sterilization apparatus described in Patent Document 1 includes a horizontal irradiation unit and a downward irradiation unit, and can irradiate ultraviolet rays in a horizontal direction, obliquely downward, and downward. Furthermore, the ultraviolet rays of 254 nm exemplified in Patent Document 1 are generally harmful to the human body. Therefore, when there is a person indoors, ultraviolet rays cannot be irradiated obliquely downward and downward. When irradiating while a person is indoors, it is limited to a range that does not irradiate the person with ultraviolet rays, such as horizontal irradiation near the ceiling.

Patent Document 2 discloses a technique of irradiating ultraviolet rays from a germicidal lamp irradiating ultraviolet rays toward the interior of a toilet to sterilize the room, but it is described that the irradiation of ultraviolet rays is stopped when the presence of a person is detected. That is, in the prior art, when a person enters an area to be sterilized, it is premised that the irradiation of ultraviolet rays is stopped.

In addition, Patent Document 3 discloses a technique of inactivating bacteria while substantially avoiding harm to human and animal body cells. This Patent Document 3 describes that microbes in food, air, and purified water can be decomposed by sterilization irradiation with ultraviolet rays, typically ultraviolet rays of UVB or UVC are used, and that these ultraviolet rays are dangerous to humans and other living things of this. Furthermore, it is described that ultraviolet rays with a wavelength exceeding 240 nm cause damage to the DNA in the nucleus of human cells; the penetration power of cells varies depending on the wavelength of ultraviolet rays. The harmfulness of the cells disappears at this point. In addition, as a specific example, it is shown that microorganisms and viruses can be selectively inactivated without damaging the cells of humans and animals using ultraviolet rays having a wavelength of 200 nm to 230 nm.

prior art literature

Patent Literature

Patent Document 1: Japanese Patent Laid-Open No. 2018-130131

Patent Document 2: Japanese Patent Application Laid-Open No. 10-248759

Patent Document 3: Japanese Patent Publication No. 2018-517488

SUMMARY OF THE INVENTION

The problem to be solved by the invention

Based on Patent Document 3, the purpose is to more efficiently inactivate microorganisms and viruses by using ultraviolet rays of 190 nm to 235 nm as a wavelength band shorter than 240 nm as ultraviolet rays for suppressing harmfulness to humans and animals.

means of solving problems

In order to solve the above-mentioned problems, one aspect of the inactivation device of the present invention is an inactivation device including: a light source unit that emits ultraviolet rays having a center wavelength in a wavelength band of 190 nm to 235 nm; a person is detected; and a control unit controls the lighting state of the light source unit, and the control unit controls a first lighting performed while the sensing unit senses the presence of a person operation and the second lighting operation performed during the period when the sensing unit does not sense the presence of a person, the amount of ultraviolet rays radiated from the light source unit is changed, and the average of the ultraviolet rays in the first lighting operation The illuminance is controlled to be lower than the average illuminance of ultraviolet rays in the second lighting operation.

In this way, by radiating ultraviolet rays in the wavelength range of 190 nm to 235 nm, which has little adverse effect on the cells of humans and animals, it is possible to perform the first lighting operation even while the presence of a human being is sensed in the target space. Irradiate predetermined ultraviolet rays to inactivate microorganisms and viruses. In addition, when the presence of a person is not sensed in the target space, the second lighting operation with a higher average illuminance of ultraviolet rays is performed, so that microorganisms and viruses in the target space can be inactivated more efficiently. That is, the lighting state is changed between the manned period and the unoccupied period, and ultraviolet irradiation more suitable for the occasion is performed.

In addition, the "average illuminance" here may be a value obtained by dividing the integrated value of the illuminance within a predetermined period by the predetermined period when ultraviolet rays are continuously emitted. In addition, in the case of performing periodic lighting, the value obtained by dividing the integrated value of the ultraviolet illuminance for each cycle by the time of one cycle may be used. In addition, when performing aperiodic random lighting, the value obtained by dividing the integrated value of the illuminance in a predetermined period by a predetermined period may be sufficient.

In addition, the second lighting operation may be controlled to stop after a certain period of time has elapsed while the sensing unit does not sense the presence of a person.

Here, “a certain period of time” is set to a time that can sufficiently inactivate microorganisms and viruses existing in the target space. Specifically, it is set to be able to achieve an inactivation rate with an inactivation rate in the selected lighting operation mode. The time to irradiate ultraviolet rays is 90% or more, desirably 99% or more, and more desirably 99.9% or more. The amount of ultraviolet rays required for inactivation varies depending on the target microorganism and virus, and is appropriately changed according to the type of the target microorganism and virus.

This makes it possible to reduce unnecessary ultraviolet irradiation after reaching a necessary amount of ultraviolet irradiation during an unoccupied period when the sensing unit does not sense the presence of a person. In particular, during an unoccupied period, bacteria and viruses are not newly introduced into the target space through a person, so the inactivated state in the target space is not deteriorated.

In addition, when inactivating bacteria using ultraviolet rays, it is necessary to consider "photorecovery of bacteria". Among bacteria, even after DNA is damaged by irradiation with ultraviolet rays, the bacteria play a role in repairing DNA damage by irradiating light with a wavelength of 300 nm to 500 nm (including the visible light region). It is produced by the action of photorecovery enzymes (eg, FAD (flavin adenine dinucleotide)) possessed by bacteria, and this phenomenon is called "photorecovery of bacteria".

However, when the bacteria were inactivated by irradiation with ultraviolet rays having a central wavelength of 190 nm to 235 nm, for example, ultraviolet rays having a wavelength of 222 nm, it was confirmed that photorecovery of the bacteria did not proceed even after the ultraviolet irradiation was irradiated with visible light. This action is considered to be because ultraviolet rays in a wavelength band shorter than the wavelength of 240 nm are efficiently absorbed by cell membranes and proteins that are components of enzymes possessed by bacteria and viruses. To describe in detail, ultraviolet light in a wavelength band shorter than 240 nm is absorbed by the surface of the human skin (such as the stratum corneum), and it is difficult to penetrate into the skin. It is safer for the skin, but bacteria and viruses are physically far more than the human body. Cells are small, and UV light can easily reach the inside even in a wavelength band shorter than 240 nm. Therefore, it is considered that it can effectively act on cells constituting bacteria and viruses, particularly cell membranes containing protein components, enzymes, and the like, thereby enhancing the effect of inhibiting functions such as photorecovery of bacteria.

That is, if the bacteria are inactivated by ultraviolet rays having a wavelength of 190 nm to 235 nm during the unmanned period, the viable quantity of the bacteria will not be recovered by the visible light irradiation even if the ultraviolet irradiation is stopped thereafter.

Therefore, after the inactivation in the target space is performed by irradiation of ultraviolet rays for a certain period of time, the inactivated state is easily maintained even if the irradiation of ultraviolet rays is stopped, and the power consumption of the inactivation device can be suppressed. In addition, ultraviolet rays are not excessively irradiated to parts (for example, wallpaper, daily utensils, etc.) existing in the object space.

In addition, after the second lighting operation is stopped, when the sensing unit senses the presence of a person, the first lighting operation may be executed.

Even after the second lighting operation is continued for a certain period of time to irradiate a required amount of ultraviolet rays into the target space, if a person enters the target space again, there is a possibility that microorganisms and viruses may be newly introduced through the person. This prevents the inactivated state, so the ultraviolet irradiation during the occupancy period can be performed by performing the first lighting operation again. Thereby, the inactivation level in the target space can be kept high.

In addition, after the second lighting operation is stopped, when the sensing unit senses the presence of a person, wait again until the sensing unit does not sense the presence of a person, and then The second lighting operation is performed in a period during which the sensing unit does not sense the presence of a person.

In this case, it is also assumed that if a person enters the target space again after the second lighting operation is performed for a certain period of time, microorganisms and viruses may be newly introduced through the person, but when the amount of ultraviolet rays to the person approaches the upper limit value In this case, instead of directly irradiating a person with ultraviolet rays, it is possible to irradiate the microorganisms and viruses remaining in the target space with ultraviolet rays at the timing when the person is no longer there, enabling a safer start that assumes the allowable limit value of the amount of ultraviolet rays for a person. control.

Furthermore, the distance from the light emitting surface of the light source unit to the inactivation target may be set to h, and the illuminance of ultraviolet rays on the surface separated from the light emitting surface by the distance h may be set to I _h ( mW/cm ² ), when the amount of ultraviolet rays required for the inactivation of the inactivation object is E (mJ/cm ² ), the predetermined time is the time for executing the irradiation time H (sec) calculated by the following formula .

H=E/(0.6×I _h )

In this case, microorganisms and viruses existing in the target space can be sufficiently inactivated. In addition, the amount of ultraviolet rays required for inactivation here refers to the amount of ultraviolet rays that can achieve 90% or more inactivation by ultraviolet irradiation, and more desirably refers to the amount of ultraviolet rays that can achieve 99% or more inactivation by ultraviolet irradiation, It is further expected to refer to the amount of ultraviolet rays that can achieve 99.9% or more inactivation by ultraviolet irradiation.

In addition, the control of the average illuminance of ultraviolet rays in the first lighting operation and the second lighting operation may be performed by changing the ratio of the lighting time and the extinguishing time of the light source unit.

Further, the first lighting operation may be controlled to perform an intermittent operation in which the lighting time during which the light source portion is turned on and the extinguishing time during which the light source portion is turned off are alternately repeated. When the unit senses the presence of a person and switches to the first lighting operation, the extinguishing time is started first, and then the lighting time is started.

This makes it easy to switch between a period in which the presence of a person is detected by the sensing unit and a period in which the presence of a person is not sensed frequently in a short period of time, for example, even when there are many people coming and going. By securing an appropriate extinguishing time, malfunction of the lighting operation can be suppressed.

Therefore, even when people come and go frequently, the light source unit does not frequently flicker.

In addition, the control of the average illuminance of ultraviolet rays in the first lighting operation and the second lighting operation may be performed by adjusting the voltage applied to the light-emitting body provided in the light source unit. In addition, the control of the average illuminance of ultraviolet rays in the first lighting operation and the second lighting operation may be performed by adjusting the frequency of voltage application to the light-emitting body provided in the light source unit.

In this way, the average illuminance of the ultraviolet rays in the first lighting operation and the second lighting operation can be realized by various control methods.

In addition, one aspect of the inactivation method of the present invention is an inactivation method that controls the lighting state of a light source unit that emits ultraviolet rays having a center wavelength in a wavelength band of 190 nm to 235 nm, the inactivation method including the following Steps: Sensing whether there is a person in the object space; in a way that the amount of ultraviolet rays emitted from the light source part is different, a first lighting action is performed during the period when the sensing part senses the existence of a person, and the The second lighting operation is performed while the sensing unit does not sense the presence of a person, and the average illuminance of the ultraviolet rays in the first lighting operation is controlled to be higher than the average illuminance of the ultraviolet rays in the second lighting operation Illumination is low.

In this way, by radiating ultraviolet rays in the wavelength range of 190 nm to 235 nm, which has little adverse effect on the cells of humans and animals, it is possible to perform the first lighting operation even while the presence of a human being is sensed in the target space. Irradiate predetermined ultraviolet rays to inactivate microorganisms and viruses. In addition, when the presence of a person is not sensed in the target space, the second lighting operation with a higher average illuminance of ultraviolet rays is performed, so that microorganisms and viruses in the target space can be inactivated more efficiently. That is, the lighting state is changed between the manned period and the unoccupied period, and ultraviolet irradiation more suitable for the occasion is performed.

Invention effect

According to one aspect of the present invention, the inactivation of microorganisms and/or viruses using ultraviolet rays in a wavelength range that suppresses adverse effects on the human body can be performed more appropriately.

Description of drawings

FIG. 1 is a schematic view of the external appearance of the inactivation device of the present embodiment.

FIG. 2 is an explanatory diagram related to an operation example of the present embodiment.

Fig. 3 is the result of a photorecovery experiment of bacteria irradiated with ultraviolet rays with a wavelength of 254 nm.

FIG. 4 shows the results of a photorecovery experiment of bacteria irradiated with ultraviolet rays with a wavelength of 222 nm.

FIG. 5 is an explanatory diagram related to an operation example of the present embodiment.

FIG. 6 is an explanatory diagram related to an operation example of the present embodiment.

FIG. 7 is an explanatory diagram related to an operation example of the present embodiment.

Description of reference numerals

11...frame body, 12...light emitting surface, 15...power supply unit, 16...control unit, 20...ultraviolet light source, 21...discharge vessel, 22...first electrode, 23...second electrode, 31...sensing unit, 100 …ultraviolet irradiation device

Detailed ways

Hereinafter, embodiments of the present invention will be described based on the drawings.

FIG. 1 is a schematic external view of the inactivation device 100 in this embodiment.

The inactivation device 100 is a device that irradiates ultraviolet rays in a space where humans and animals exist, and inactivates microorganisms and viruses existing in the space and on the surfaces of objects in the space.

Here, the above-mentioned space includes, for example, spaces in offices, commercial facilities, medical facilities, station facilities, schools, governments, theaters, hotels, restaurants, and other facilities, and in vehicles such as cars, trains, buses, taxis, airplanes, and ships. Space. In addition, the above-mentioned space may be a closed space such as a ward, a conference room, a toilet, and an elevator, or an unclosed space.

The inactivation device 100 irradiates the target space with ultraviolet rays having a wavelength of 190 to 235 nm (more preferably, ultraviolet rays in the wavelength range of 200 nm to 230 nm) that have less adverse effects on human and animal cells, and irradiates the surface of the object existing in the target space. , Inactivation of harmful microorganisms and viruses in space. Here, the above-mentioned objects include human bodies, animals, and objects. In addition, the target space to be irradiated with ultraviolet rays is not limited to spaces in which humans and animals actually exist, but also includes spaces where humans and animals enter and exit without humans or animals.

In addition, the term "inactivation" as used herein refers to killing microorganisms and viruses (or making them lose their infectivity and toxicity).

As shown in FIG. 1 , the inactivation device 100 includes a light source unit that generates ultraviolet rays, a control unit 16 that controls lighting of the light source unit, and a housing 11 that accommodates the light source unit and the control unit 16 . The frame body 11 is formed with a light emission surface 12 that emits ultraviolet rays. Specifically, the opening part 11a which becomes a light exit window which radiates an ultraviolet-ray is formed. A window member made of, for example, quartz glass is provided in the opening 11a, and ultraviolet rays are radiated from the window member. In addition, a filter or the like that blocks light in an unnecessary wavelength band may be provided in the opening portion 11a.

Inside the housing 11, an excimer lamp 20 is accommodated as an ultraviolet light source. The excimer lamp 20 may be, for example, a KrCl excimer lamp that emits ultraviolet rays having a center wavelength of 222 nm. In addition, the ultraviolet light source is not limited to a KrCl excimer lamp, and may be a light source that emits ultraviolet rays in a wavelength range of 190 nm to 235 nm. Moreover, the light source part is comprised by the housing|casing 11 and the ultraviolet light source (excimer lamp 20).

The penetrating force of UV radiation varies depending on the wavelength, and the shorter the wavelength, the smaller the penetrating force. For example, short-wavelength UV radiation such as about 200 nm passes through water very efficiently, but is largely absorbed by the outer part (cytoplasm) of human cells, and sometimes does not have enough energy to reach the nucleus containing DNA sensitive to UV radiation. Therefore, the above-mentioned short-wavelength UV radiation has less adverse effects on human cells. On the other hand, ultraviolet rays with wavelengths exceeding 240 nm can damage DNA in the nucleus of human cells. In addition, it is known that ultraviolet rays with a wavelength of less than 190 nm generate ozone.

Therefore, in the present embodiment, as the ultraviolet light source, an ultraviolet light source that emits ultraviolet rays in a wavelength range of 190 nm to 235 nm, which has less adverse effects on the human body and can obtain an inactivation effect, and does not substantially radiate other UVC rays is used. In addition, as a wavelength band with higher safety, an ultraviolet light source having a peak wavelength in a wavelength range of 200 nm to 230 nm can also be used.

The excimer lamp 20 includes a straight tubular discharge vessel 21 whose both ends are hermetically sealed. The discharge vessel 21 is made of, for example, quartz glass. In addition, a rare gas and a halogen are enclosed as luminescent gas inside the discharge vessel 21 . In the present embodiment, krypton chloride (KrCl) gas is used as the light-emitting gas. In this case, the peak wavelength of the obtained emitted light was 222 nm.

In addition, the luminescent gas is not limited to the above. For example, krypton bromide (KrBr) gas or the like can also be used as the light-emitting gas. In the case of the KrBr excimer lamp, the peak wavelength of the emitted light obtained was 207 nm.

In addition, in FIG. 1, although the inactivation apparatus 100 is provided with the several (three) discharge vessel 21, the number of the discharge vessel 21 is not specifically limited.

A pair of electrodes (a first electrode 22 and a second electrode 23 ) are arranged in contact with the outer surface of the discharge vessel 21 . The first electrode 22 and the second electrode 23 are arranged apart from each other in the tube axis direction (Y direction) of the discharge vessel 21 on the side surface (the -Z direction surface) of the discharge vessel 21 opposite to the light extraction surface.

Furthermore, the discharge vessel 21 is configured to contact and span these two electrodes 22 , 22 . Specifically, grooves are formed in the two electrodes 22 and 23 , and the discharge vessel 21 is fitted into the grooves of the electrodes 22 and 23 .

One of the pair of electrodes (for example, the first electrode 22 ) is a high-voltage side electrode, and the other electrode (for example, the second electrode 23 ) is a low-voltage side electrode (ground electrode). The lamp is turned on by applying a high-frequency voltage between the first electrode 22 and the second electrode 23 .

The light extraction surface of the excimer lamp 20 is arranged to face the light exit window. Therefore, the light emitted from the excimer lamp 20 is emitted from the light emission surface 12 of the inactivation device 100 through the light emission window.

Here, the electrodes 22 and 23 may be formed of a metal member having reflectivity with respect to the light emitted from the excimer lamp 21 . In this case, the light emitted in the −Z direction from the discharge vessel 21 can be reflected to travel in the +Z direction.

The optical filter can be provided in the opening part 11a which becomes a light exit window as mentioned above. The filter may be, for example, a wavelength that transmits light in a wavelength range of 190 nm to 235 nm (more preferably, light in a wavelength range of 200 nm to 230 nm), which has less adverse effects on the human body, and cuts off the UVC wavelength band of wavelengths of 236 nm to 280 nm. Choose a filter. Specifically, each ultraviolet illuminance at wavelengths 236 nm to 280 nm is reduced to 1% or less with respect to the ultraviolet illuminance at the peak wavelength in the wavelength band of 190 nm to 235 nm. As the wavelength selective filter, for example, a filter having a dielectric multilayer film formed of a HfO ₂ layer and a SiO ₂ layer can be used.

In addition, as the wavelength selective filter, a filter having a dielectric multilayer film formed of a SiO ₂ layer and an Al ₂ O ₃ layer can also be used. In this way, by providing a filter in the light exit window, even when light harmful to humans is emitted from the excimer lamp 20 , the leakage of the light to the outside of the housing 11 can be suppressed more reliably.

Further, the inactivation device 100 is provided with a sensing unit 31 for sensing the presence of a person in the target space. The sensing portion 31 may be formed integrally with the inactivation device 100, or may be sensed by receiving a signal from the outside. As one embodiment, a human sensor can be used. The human-sensing sensor may be, for example, a pyroelectric infrared sensor that senses changes in heat (infrared rays) emitted from a human body or the like. In addition, as another embodiment, it is also possible to sense the occupied time and the non-occupied time in the target space in which the use of people is assumed.

In addition, as shown in FIG. 1 , the inactivation device 100 includes a power supply unit 15 and a control unit 16 .

The power supply unit 15 includes power supply components such as an inverter to which power from the power supply is supplied, and cooling components such as a radiator for cooling the power supply components. In addition, the control unit 16 controls the lighting of the excimer lamp 20 constituting the light source unit.

FIG. 2 is an explanatory diagram showing an embodiment of the lighting operation of the present invention.

Based on the signal from the sensing unit 31 , the control unit 16 senses the presence of a person in the target space (here, also referred to as a presence period) and a period when the presence of a person is not sensed in the target space (here, Also referred to as unoccupied period), in order to vary the average illuminance of the ultraviolet rays radiated from the light source unit, the first lighting operation is performed during the unoccupied period, and the second lighting operation is performed during the unoccupied period. As shown in FIG. 2 , when the ultraviolet rays are continuously emitted, the average illuminance is a value obtained by dividing the integrated value of the illuminance in a predetermined period by the above-mentioned predetermined period.

The lighting control is performed such that the first lighting operation performs lighting with a relatively low average illuminance of ultraviolet rays, and the second lighting operation performs lighting with a relatively high average illuminance of ultraviolet rays. For example, the lighting state may be controlled so that the average illuminance in the first lighting operation is set to 1 μW/cm ² or less, and the average illuminance in the second lighting operation is set to a value exceeding 1 μW/cm ² .

According to ACGIH (American Conference of Governmental Industrial Hygienists: American Conference of Industrial Hygienists), JIS Z 8812 (Measurement of Harmful Ultraviolet Radiation), the amount of ultraviolet radiation per day (8 hours) to the human body is determined for each wavelength Tolerable limit value (TLV: Threshold LimitValue), it is required to determine the illuminance and irradiation amount of ultraviolet rays irradiated per predetermined time so as not to exceed the allowable limit value. This allowable limit value may be revised in the future, but for example, the average illuminance in the first lighting operation performed while there is a person may be a value that does not exceed the allowable limit value of ultraviolet radiation even if the irradiation is continued for 8 hours.

In the present embodiment, as shown in FIG. 2 , when switching from a manned period to an unoccupied period at time t1, the first lighting operation is switched to the second lighting operation, and the average illuminance is switched from low illuminance to high illuminance. In addition, after that, when switching from the unoccupied period to the occupied period at time t2, the second lighting operation is switched to the first lighting operation, and the average illuminance is switched from high illuminance to low illuminance.

Therefore, when there is no person in the target space, the second lighting operation with a higher average illuminance of ultraviolet rays is performed, so that microorganisms and viruses in the target space can be inactivated more efficiently. In addition, even when the presence of a person is sensed in the target space, by executing the first lighting operation, predetermined ultraviolet rays can be irradiated, thereby inactivating microorganisms and viruses.

Further, as shown in FIG. 2 , the second lighting operation may be controlled so that the operation is stopped (turned off) after the operation for a predetermined period of time is completed. That is, as shown in FIG. 2 , after switching from the manned period to the unoccupied period at the time t3, the irradiation of the ultraviolet rays may be stopped at the time t4 after a certain period of time has elapsed.

The inactivation in the space can be achieved by performing the necessary and sufficient ultraviolet irradiation in the object space during the unmanned period. Therefore, when it is difficult to imagine that microorganisms or viruses have newly entered through a person, the lighting operation is stopped (turned off), whereby excessive ultraviolet irradiation into the target space can be suppressed. Thereby, power consumption can be suppressed. In addition, the light-emitting operation time of the light source unit can be reduced, and the service life of the inactivation device 100 can be extended.

In addition, the stop of the second lighting operation will be described in detail assuming the inactivation of bacteria. When inactivating bacteria using ultraviolet rays, it is necessary to consider "photorecovery of bacteria". Among bacteria, even after DNA is damaged by irradiation with ultraviolet rays, the bacteria play a role in repairing DNA damage by irradiating light with a wavelength of 300 nm to 500 nm (including the visible light region). It is produced by the action of photorecovery enzymes (eg, FAD (flavin adenine dinucleotide)) possessed by bacteria, and this phenomenon is called "photorecovery of bacteria".

However, when the bacteria are inactivated by irradiation with ultraviolet rays having a central wavelength of 190 nm to 235 nm, for example, ultraviolet rays having a wavelength of 222 nm, photorecovery of the bacteria is not performed even after the ultraviolet irradiation with visible light. That is, if the bacteria are inactivated by ultraviolet rays having a wavelength of 190 nm to 235 nm during the unmanned period, the viable quantity of the bacteria will not be recovered by the visible light irradiation even if the ultraviolet irradiation is stopped thereafter.

Therefore, after the inactivation in the target space is performed by ultraviolet irradiation for a certain period of time, the inactivated state is easily maintained even if the ultraviolet irradiation is stopped, and the power consumption of the inactivation device 100 can be suppressed. In addition, ultraviolet rays are not excessively irradiated to parts (for example, wallpaper, daily utensils, etc.) existing in the object space. This is an effect that could not be achieved by the conventionally known low-pressure mercury lamp (main wavelength: 254 nm) as a germicidal lamp.

3 and 4 show the verification results of verifying the inactivation effect of bacteria using a KrCl excimer lamp with a wavelength of 200 nm to 230 nm (dominant wavelength of 222 nm) and a low-pressure mercury lamp with a dominant wavelength of 254 nm.

3 is the result of the photorecovery experiment of bacteria irradiated with ultraviolet rays using a low-pressure mercury lamp having a dominant wavelength of 254 nm, and FIG. 4 is the result of a photorecovery experiment of bacteria irradiated with ultraviolet rays at wavelengths of 200 nm to 230 nm (dominant wavelength of 222 nm). Here, as the bacteria to be inactivated, Staphylococcus aureus was irradiated with ultraviolet rays in an environment irradiated with visible light containing light having a wavelength of 300 nm to 500 nm, and changes in the survival rate of bacteria after ultraviolet irradiation were confirmed. In addition, Staphylococcus aureus is a bacterium that has a photorecovery enzyme and produces photorecovery of bacteria by being irradiated with visible light.

In FIGS. 3 and 4 , the horizontal axis represents the elapsed time (h), and the vertical axis represents the log survival rate of bacteria. In FIG. 3 and FIG. 4 , the experimental results a to d show the survival rate of bacteria when the ultraviolet irradiation amount was 0 mJ/cm ² , 5 mJ/cm ² , 10 mJ/cm ² , and 15 mJ/cm ² . Variety. In addition, here, the ultraviolet irradiation time was set to 30 minutes, and the ultraviolet irradiation was stopped after that, and the change of the survival rate of bacteria was confirmed.

As shown in FIG. 3 , the survival rate of bacteria increased over time. That is, in an environment irradiated with visible light, photorecovery of bacteria was performed after irradiation with ultraviolet rays having a wavelength of 254 nm. Specifically, by irradiation with visible light, the survival number of bacteria was largely recovered in about 1 to 2 hours.

On the other hand, as shown in FIG. 4 , in the case of irradiating with ultraviolet rays having a wavelength of 222 nm, recovery of the bacteria was not confirmed even when visible light was irradiated. That is, photorecovery of bacteria is hindered.

Since the bacteria whose photorecovery is inhibited are in a state in which DNA damage remains, they are inactivated instead of proliferating. Ultraviolet irradiation with a wavelength of 222 nm can effectively reduce the recovery and proliferation of bacteria. Therefore, an inactivation system that irradiates ultraviolet rays with a wavelength of 222 nm effectively functions in an environment where photorecovery of bacteria is easy, specifically, an environment where visible light including light with a wavelength of 300 nm to 500 nm is irradiated.

As described above, the inactivation device 100 of the present invention controls the lighting operation by changing the control of the lighting operation during the unoccupied period and the unoccupied period, and the lighting operation during the unoccupied period is turned off after a certain period of time for sufficient ultraviolet irradiation in the target space has elapsed, This enables more efficient inactivation.

In addition, the time (fixed time) in which the time of the second lighting operation lasts can be calculated as follows, for example.

Let E be the amount of ultraviolet rays (mJ/cm ² ) that can inactivate 90% or more, and more desirably 99% or more of microorganisms and viruses to be inactivated When I ₅₀ is used and the distance from the light irradiation surface 12 to the object to be inactivated (inactivation target) is set to h, it is also possible to calculate a sufficient inactivation requirement based on the following calculation formula (1). The irradiation time H.

Necessary irradiation time H=E/(0.6×I ₅₀ ×(50/h) ² )...(1)

In addition, in the above-mentioned formula (1), I ₅₀ ×(50/h) ² is the illuminance I _h of the ultraviolet rays on the surface separated by the distance h from the light emission surface 12 . That is, the irradiation time H is set so that the above-mentioned inactivation target can be inactivated in a region (60% illuminance region) where the ultraviolet illuminance is 60% of the maximum illuminance of ultraviolet rays on the surface separated by the distance h from the light emitting surface 12 . time.

For example, in an area separated by a distance of 50 cm from the light emitting surface 12 , the illuminance is 53.6 μW/cm ² , the predetermined amount of ultraviolet rays required for 99% of virus inactivation is 2 mJ/cm ² , and the distance from the light emitting surface 12 to the object is 53.6 μW/cm 2 . When the distance h is 200 cm, the necessary irradiation time H is 995 seconds (about 17 minutes). In addition, assuming that the second lighting operation is an intermittent operation in which the lighting time and the extinguishing time are alternately repeated, when the lighting time is 15 seconds and the extinguishing time is 30 seconds, the necessary second lighting operation The drive time can be estimated as 0.8 hours. By such calculation, the time (fixed time) during which the time of the second lighting operation lasts may be determined so that the driving time becomes 0.8 hours or more. Here, for example, a certain period of time can be set to 1 hour. In addition, when the inactivation rate is set to a higher value (for example, 99.9%), it is necessary to set the predetermined time width to be longer.

In addition, as shown in FIG. 2 , after the second lighting operation is stopped, the first lighting operation may be executed when the presence of a person is sensed by the sensing unit 31 . That is, as shown in FIG. 2 , after the second lighting operation is stopped at time t4, when the presence of a person is sensed at time t5, the first lighting operation may be performed at this time t5.

In addition, after stopping the second lighting operation, when the presence of a person is sensed by the sensing unit 31, the standby may be performed again until the presence of a person is no longer sensed by the sensing unit 31, and then When the unit 31 no longer senses the presence of a person, the second lighting operation is performed. That is, as shown in FIG. 5 , after the second lighting operation is stopped at time t4, when the presence of a person is sensed at time t5, the first lighting operation may not be performed at the time t5, and the first lighting operation may be performed at a later time. When the presence of a person is no longer sensed at t6, the second lighting action is performed.

Here, either or both of the first lighting operation and the second lighting operation may be performed periodically, and as shown in FIG. 6 , the lighting operation and the extinguishing operation may be alternately repeated ( An intermittent operation in which the lighting time during which the light source portion is turned on and the extinguishing time during which the light source portion is turned off are alternately repeated).

FIG. 6 is an explanatory diagram showing one form of the lighting operation of the present invention, and shows one form when the first lighting operation and the second lighting operation are each performed intermittently. Based on the signal from the sensing unit 31, a period in which the presence of a person is sensed in the object space (here, also referred to as a person's period) and a period in which the presence of a person is not sensed in the object space (here, also referred to as a period of presence) Unmanned period), in order to vary the average illuminance of ultraviolet rays radiated from the light source unit, the control is performed so that the first lighting operation is performed during the unoccupied period and the second lighting operation is performed during the unoccupied period.

The average illuminance here may be determined as the average illuminance per cycle.

That is, as shown in FIG. 6 , in the case of performing periodic intermittent operation, the average illuminance is illuminance×duty. Here, the duty ratio is the ratio of the lighting time to the sum of the lighting time and the extinguishing time, and is a value represented by the lighting time/(the lighting time+the extinguishing time).

The first lighting operation performs a lighting operation with a relatively low average illuminance of ultraviolet rays, and the second lighting operation performs a lighting operation with a relatively high average illuminance of ultraviolet rays. For example, the lighting state may be controlled so that the average illuminance in the first lighting operation is set to 1 μW/cm ² or less, and the average illuminance in the second lighting operation is set to a value exceeding 1 μW/cm ² .

As shown in FIG. 6 , when switching from the manned period to the unoccupied period at time t11 , the first lighting operation is switched to the second lighting operation, and the average illuminance is switched from low illuminance to high illuminance. Here, the average illuminance is switched from low illuminance to high illuminance by shortening the turn-off time in the periodic turn-on/turn-off cycle. In addition, after that, when switching from the unoccupied period to the occupied period at time t12, the second lighting operation is switched to the first lighting operation, and the average illuminance is switched from high illuminance to low illuminance. That is, the extinguishing time becomes longer.

Therefore, as in the embodiment shown in FIG. 2 , the second lighting operation with a higher average illuminance of ultraviolet rays is performed while there is no person in the target space, so that the microorganisms and viruses in the target space can be more effectively eliminated. inactivated. In addition, even when the presence of a person is sensed in the target space, by executing the first lighting operation, predetermined ultraviolet rays can be irradiated, thereby inactivating microorganisms and viruses.

In addition, as in the embodiment shown in FIG. 2 , the second lighting operation may be controlled so that the operation is stopped (turned off) after the operation for a predetermined period of time is completed. That is, as shown in FIG. 6 , after switching from the manned period to the unoccupied period at time t13 , the irradiation of ultraviolet rays may be stopped at time t14 after a certain period of time has elapsed. Here, the above-mentioned certain period of time is the period of time during which the irradiation time H (sec) calculated by the above-mentioned formula (1) is executed.

The inactivation in the space can be achieved by performing the necessary and sufficient ultraviolet irradiation in the object space during the unmanned period. Therefore, when it is difficult to imagine that microorganisms or viruses have newly entered through a person, the lighting operation is stopped (turned off), whereby excessive ultraviolet irradiation into the target space can be suppressed. Thereby, power consumption can be suppressed. In addition, the light-emitting operation time of the light source unit can be reduced, and the service life of the inactivation device 100 can be extended.

In addition, as shown in FIG. 6 , after the second lighting operation is stopped, the first lighting operation may be executed when the presence of a person is sensed by the sensing unit 31 . That is, as shown in FIG. 6 , after the second lighting operation is stopped at time t14 , when the presence of a person is sensed at time t15 , the first lighting operation may be performed at this time t15 .

Furthermore, when the sensing unit 31 senses the presence of a person and switches to the first lighting operation, the extinguishing time may be started first, and then the lighting time may be started. That is, as shown in FIG. 7 , after the second lighting operation is stopped at time t14 , when the presence of a person is sensed at time t15 , the turn-off time in the periodic turn-on/turn-off cycle may be awaited. At the subsequent time t16, the lighting time is started.

When the lighting operation is started, the lighting time may become relatively long when the presence/absence of a person fluctuates drastically. By starting from the extinguishing time, it is easy to maintain the lighting time at an appropriate value.

In addition, in the control of the average illuminance of ultraviolet rays in the first lighting operation and the second lighting operation, by changing the ratio of the lighting time and the extinguishing time of the light source portion, the voltage applied to the light-emitting body provided in the light source portion can be adjusted and adjusted. It is realized by various control methods, such as the frequency of the voltage applied to the light-emitting body provided in the light source unit.

In addition, in the first lighting operation and the second lighting operation, when the intermittent operation in which the lighting time and the extinguishing time are alternately repeated is performed, in the above-described embodiment, the light source unit is changed by adjusting the extinguishing time. However, the lighting time can also be adjusted, and both the lighting time and the extinguishing time can be adjusted.

In addition, in the present embodiment, it is proposed to control the second lighting operation to stop after a certain period of time has elapsed while the sensing unit 31 does not sense the presence of a person. This is because it is easy to maintain the inactivated state by using ultraviolet rays in a wavelength band capable of inhibiting photorecovery of bacteria. However, after the control to stop the second lighting operation, the lighting may be performed again after a predetermined time has elapsed even if a person is not present.

In the target space, there is a high possibility that new bacteria and viruses are brought into the space through a person, but the possibility that bacteria and viruses flow into the space from the outside even without a person is also considered. In this case, additional control may be performed to maintain the inactivation level in the object space by performing the lighting action again when the extinguishing time is long.

In addition, based on the above-mentioned knowledge, the following device configuration and inactivation method can also be considered.

For example, it may be an inactivation device characterized by comprising: a light source unit that radiates ultraviolet rays having a center wavelength in a wavelength band of 190 nm to 235 nm; a sensing unit that senses the presence or absence of a person in the target space; and a control unit that controls a lighting state of the light source unit, the control unit includes a second lighting operation performed while the sensing unit does not sense the presence of a person, the second lighting operation It is controlled to stop after a certain period of time has elapsed during a period in which the sensing unit does not sense the presence of a person.

Furthermore, in the above-mentioned inactivation device, the distance from the light emission surface of the light source unit to the inactivation target may be set to h, and the surface of the surface separated from the light emission surface by the distance h may be set to h. When the illuminance of ultraviolet rays is set to 1 _h (mW/cm ² ) and the amount of ultraviolet rays required for inactivation of the inactivation object is set to E (mJ/cm ² ), the predetermined time is calculated by the following formula The time of irradiation time H (sec).

H=E/(0.6×I _h )

Alternatively, there may be an inactivation method characterized by controlling the lighting state of a light source unit emitting ultraviolet rays having a center wavelength in a wavelength band of 190 nm to 235 nm, the inactivation method comprising the step of: Sensing whether there is a person in the space; and performing a second lighting action during a period when the sensing portion does not sense the presence of a person, the second lighting action is controlled so as not to sense the sensing portion The period in which the presence of a person is detected is stopped after a certain period of time has elapsed.

Furthermore, in the above-mentioned inactivation method, the distance from the light emission surface of the light source unit to the inactivation object may be set to h, and the surface of the surface separated from the light emission surface by the distance h may be set to h. When the illuminance of ultraviolet rays is set to 1 _h (mW/cm ² ) and the amount of ultraviolet rays required for inactivation of the inactivation object is set to E (mJ/cm ² ), the predetermined time is calculated by the following formula The time of irradiation time H (sec).

H=E/(0.6×I _h )

With the above-described configuration, the second lighting operation controlled so that the presence of a person is not detected is stopped after a certain period of time has elapsed during a period in which the sensing unit does not sense the presence of a person.

Here, “a certain period of time” is set to a time that can sufficiently inactivate microorganisms and viruses existing in the target space. Specifically, it is set to be able to achieve an inactivation rate with an inactivation rate in the selected lighting operation mode. The time to irradiate ultraviolet rays is 90% or more, desirably 99% or more, and more desirably 99.9% or more. The amount of ultraviolet rays required for inactivation varies depending on the target microorganism and virus, and is appropriately changed according to the type of the target microorganism and virus.

This makes it possible to reduce unnecessary ultraviolet irradiation after reaching a necessary amount of ultraviolet irradiation during an unoccupied period when the sensing unit does not sense the presence of a person. In particular, during an unoccupied period, bacteria and viruses are not newly introduced into the target space through a person, so the inactivated state in the target space is not deteriorated.

Furthermore, as described above, ultraviolet rays having a center wavelength of 190 to 235 nm have the effect of suppressing the function of "photorecovery of bacteria". Therefore, after the inactivation in the target space is performed by ultraviolet irradiation for a certain period of time, even if the ultraviolet rays are irradiated It is also easy to maintain the inactivated state even if it is stopped. That is, inactivation can be performed more efficiently, and it is possible to suppress excessive irradiation of ultraviolet rays to parts (for example, wallpaper, daily utensils, etc.) existing in the target space. Thereby, the power consumption and the service life of the inactivation device can be suppressed.

In the above-described lighting operation, after the second lighting operation is stopped, when the sensing unit senses the presence of a person, control may be performed to continue the stopped state. In this case, the second lighting operation is performed while the presence of a person is not sensed again. In addition, the second lighting operation may be controlled to stop after a certain period of time has elapsed.

Even after the second lighting operation is continued for a certain period of time to irradiate a required amount of ultraviolet rays into the target space, if a person enters the target space again, there is a possibility that microorganisms and viruses may be newly introduced through the person. This prevents the deactivated state. Therefore, after the second lighting operation is stopped, when the sensing unit senses the presence of a person, the first lighting operation can be performed again, so that a person can be performed. during UV exposure. Thereby, the inactivation level in the target space can be kept high.

Alternatively, in the above-described lighting operation, after the second lighting operation is stopped, when the sensing unit senses the presence of a person, the first lighting operation and the second point may be executed. Lighting action Different lighting action. In this case, the second lighting operation is performed when the presence of a person is not sensed again. In addition, the second lighting operation may be controlled to stop after a certain period of time has elapsed.

According to the above-mentioned aspect, the inactivation of microorganisms and/or viruses using ultraviolet rays in a wavelength range that suppresses adverse effects on the human body can be performed efficiently and more appropriately.

Claims (10)

1. An inactivation device is characterized by comprising:

a light source unit for emitting ultraviolet rays having a central wavelength in a wavelength band of 190nm to 235 nm;

a sensing unit that senses whether or not a person is present in the target space; and

a control unit for controlling the lighting state of the light source unit,

the control unit performs control in the following manner: a first lighting operation performed during a period in which the sensing unit senses the presence of a person and a second lighting operation performed during a period in which the sensing unit does not sense the presence of a person are provided, and an amount of ultraviolet rays emitted from the light source unit is changed,

the average illuminance of the ultraviolet light in the first lighting operation is controlled to be lower than the average illuminance of the ultraviolet light in the second lighting operation.

2. The inactivation device of claim 1,

the second lighting operation is controlled to stop after a certain time has elapsed while the sensing portion does not sense the presence of a person.

3. The inactivation device of claim 2,

and performing a first lighting action when the sensing part senses the presence of a person after the second lighting action is stopped.

4. The inactivation device of claim 2,

after stopping the second lighting operation, when the sensing unit senses the presence of a person, the lighting apparatus stands by again until the sensing unit no longer senses the presence of a person, and when the sensing unit no longer senses the presence of a person, the lighting apparatus performs the second lighting operation.

5. The inactivation device of any of claims 2 to 4,

in a position toH is a distance from a light emission surface of the light source unit to the inactivation target, and I is an illuminance of ultraviolet light on a surface separated from the light emission surface by the distance h_h(mW/cm²) Setting the amount of ultraviolet rays required for inactivation of the inactivation target as E (mJ/cm)²) When the temperature of the water is higher than the set temperature,

the certain time is a time for which the irradiation time h (sec) calculated by the following equation is performed,

H＝E/(0.6×I_h)。

6. the inactivation device of any of claims 1 to 4,

the average illuminance of ultraviolet light in the first lighting operation and the second lighting operation is controlled by changing a ratio of a lighting time to a lighting-off time of the light source unit.

7. The inactivation device of any of claims 1 to 4,

the first lighting operation is controlled to perform an intermittent operation of alternately repeating a lighting time during which the light source unit is turned on and a turning-off time during which the light source unit is turned off,

when the sensing unit senses the presence of a person and switches to the first lighting operation, the turning-off time is started first, and then the lighting time is started.

8. The inactivation device of any of claims 1 to 4,

the average illuminance of ultraviolet light in the first lighting operation and the second lighting operation is controlled by adjusting the voltage applied to the light emitter provided in the light source unit.

9. The inactivation device of any of claims 1 to 4,

the average illuminance of ultraviolet light in the first lighting operation and the second lighting operation is controlled by adjusting the frequency of the voltage applied to the light emitter provided in the light source unit.

10. An inactivation method for controlling a lighting state of a light source unit that emits ultraviolet light having a center wavelength in a wavelength band of 190nm to 235nm, the inactivation method comprising the steps of:

sensing whether a person is present in the object space; and

performing a first lighting operation while the sensing portion senses the presence of a person and performing a second lighting operation while the sensing portion does not sense the presence of a person, such that the amounts of ultraviolet rays emitted from the light source portion are different,

the average illuminance of the ultraviolet light in the first lighting operation is controlled to be lower than the average illuminance of the ultraviolet light in the second lighting operation.

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