CN113842479A

CN113842479A - Ultraviolet irradiation apparatus and ultraviolet irradiation method

Info

Publication number: CN113842479A
Application number: CN202111238742.4A
Authority: CN
Inventors: 内藤敬祐; 寺田庄一; 佐畠健一
Original assignee: Ushio Denki KK
Current assignee: Ushio Denki KK
Priority date: 2020-12-01
Filing date: 2021-10-25
Publication date: 2021-12-28
Anticipated expiration: 2041-10-25
Also published as: CN113842479B; JP6977899B1; JP2022087781A; WO2022118780A1

Abstract

The present invention addresses the problem of providing an ultraviolet irradiation device that can effectively and appropriately inactivate microorganisms and/or viruses using ultraviolet light in a wavelength range in which adverse effects on the human body are suppressed. The ultraviolet irradiation device is provided with: a light source unit having a light emission surface for emitting ultraviolet light having a wavelength band of 190nm to 235 nm; a control unit for controlling the lighting of the light source unit; and a sensing portion that senses the presence of a person. The control unit includes a first operation period and a second operation period, and the second operation period is a period controlled as follows: when the presence of a person is not sensed by the sensing unit, ultraviolet rays are emitted from the light source unit, and when the presence of a person is sensed by the sensing unit, the emission of ultraviolet rays is stopped, and the amount of ultraviolet rays per unit time during a period in which the presence of a person is sensed in the first operation period is controlled to be smaller than the amount of ultraviolet rays per unit time during a period in which the presence of a person is not sensed in the second operation period.

Description

Ultraviolet irradiation apparatus and ultraviolet irradiation method

Technical Field

The present invention relates to an ultraviolet irradiation apparatus and an ultraviolet irradiation method for inactivating harmful microorganisms and viruses by irradiating ultraviolet rays.

Background

Microorganisms (bacteria, fungi, etc.) and viruses existing in spaces or on surfaces of objects sometimes cause infectious diseases in humans and animals other than humans, and the expansion of the infectious diseases may threaten lives. In particular, infection is likely to spread in facilities such as medical facilities, schools, and governments, places where people are frequently concentrated such as vehicles such as automobiles, electric trains, buses, airplanes, and ships, and places where people frequently come and go.

Patent document 1 discloses a technique for inactivating bacteria while substantially avoiding damage to human or animal body cells. Patent document 1 describes that microorganisms in food, air, and purified water can be decomposed by ultraviolet sterilization irradiation, typically ultraviolet rays using UVB or UVC, and that these ultraviolet rays are dangerous to humans and other living things. Further, it is described that: ultraviolet rays having a wavelength of over 240nm cause damage to DNA in the nucleus of a human body; ultraviolet rays have different cell penetration forces depending on the wavelength, and the smaller the penetration force of short-wavelength radiation, the less harmful the ultraviolet rays are to human cells.

Documents of the prior art

Patent document

Patent document 1: japanese patent No. 6025756

Disclosure of Invention

Problems to be solved by the invention

Based on patent document 1, it has been studied to sterilize at least one of bacteria existing in a space where humans and animals are present and bacteria existing on the surface of an object by using light having a wavelength band of 190nm to 235nm as ultraviolet rays which can suppress harmful effects on humans and animals.

According to ACGIH (American Conference of Governmental Industrial Hygienists: American Conference of Industrial health experts), JIS Z8812 (method of measuring harmful ultraviolet radiation), with respect to the amount of ultraviolet radiation irradiated per day (8 hours) of the human body, an allowable Limit Value (TLV) is determined for each wavelength, and it is required that the illuminance and the amount of ultraviolet radiation irradiated per prescribed time are determined to such an extent that the allowable Limit Value is not exceeded. The allowable limit value may be modified in the future, but it is considered that it is preferable to previously determine the upper limit value of the ultraviolet irradiation amount in terms of safer operation.

In an environment where the human and animal are assumed to be present, even when the upper limit of the ultraviolet irradiation amount is determined to be a predetermined value, it is desired to inactivate bacteria and viruses more efficiently.

On the other hand, in an environment with many human trips, aerosol infection of bacteria and viruses from human to human is likely to occur, and the number of attached bacteria, mold, and the like present on the surface of an object in the environment increases due to the chance of contact with human, and thus it is difficult to efficiently inactivate bacteria, fungi, and viruses in the environment.

Accordingly, an object of the present invention is to provide an ultraviolet irradiation apparatus capable of effectively and appropriately inactivating microorganisms and/or viruses using ultraviolet rays in a wavelength range in which adverse effects on the human body are suppressed.

Means for solving the problems

In order to solve the above problem, an embodiment of the ultraviolet irradiation apparatus of the present invention includes: a light source unit having a light emission surface that emits ultraviolet light having a wavelength band of 190nm to 235 nm; a control unit that controls lighting of the light source unit; and a sensing unit that senses the presence of a person, wherein the control unit includes a first operation period and a second operation period, and the second operation period is a period controlled as follows: and a control unit that controls the light source unit to emit ultraviolet light when the presence of a person is not sensed by the sensing unit, and stops the emission of the ultraviolet light when the presence of a person is sensed by the sensing unit, wherein an amount of ultraviolet light per unit time in a period in which the presence of a person is sensed in the first operation period is controlled to be smaller than an amount of ultraviolet light per unit time in a period in which the presence of a person is not sensed in the second operation period.

In this way, since ultraviolet rays having a wavelength range of 190nm to 235nm, which has little adverse effect on cells of humans and animals, are emitted, it is possible to inactivate bacteria and viruses by irradiating ultraviolet rays even in a space where humans are present. In the first operation period, the ultraviolet ray amount in the space including the person may be set to a predetermined value (upper limit value) or less.

Thus, even when there are many people, ultraviolet irradiation can be performed in the target space, and ultraviolet irradiation can be effectively performed on floating microorganisms such as bacteria and viruses existing in aerosol and droplets. In particular, when planktonic microorganisms move to the vicinity of the light emission surface, ultraviolet rays of higher intensity are irradiated, and therefore effective inactivation of planktonic microorganisms is easily achieved.

After the first operation period ends, a second operation period is executed. During the second operation, the ultraviolet rays are not irradiated into the space including the person, but are irradiated during a time (absence time) when the presence of the person is not sensed. This enables efficient irradiation of ultraviolet light to a space other than a space including a person, such as bacteria and mold adhering to the surface of an object, and inactivation of the bacteria and mold. In this way, the first operation period can be set to a suitable range by irradiating the space including the human with ultraviolet light for a predetermined time, and the microorganisms adhered to the surface of the object in the space can be inactivated by suitably irradiating the ultraviolet light even after the first operation period is completed.

In addition, the control unit may set an operable operation time in the first operation period, and the control unit may perform control such that the second operation period is started after the first operation period is ended.

In this way, the first operation period is determined by the operation time set in the control unit, and it is possible to set that the ultraviolet irradiation amount to the human does not exceed the upper limit value within the set operation time range. This enables supply of an appropriate amount of ultraviolet light into the target space including the person. Further, by moving to the second operation period after the elapse of the operating time, it is possible to realize concentrated ultraviolet irradiation on an object other than a human, for example, an object existing in the target space, to which attached microorganisms are attached.

In this case, the first operation period is preferably set to a time zone in which the frequency of human movement is high, and the second operation period is preferably set to a time zone in which the frequency of human movement is low. In this way, the operation time during the first operation period can be set appropriately according to the use situation.

Further, the operating time set during the first operation may be reset to an initial value after a time longer than the operating time has elapsed.

Thus, the first action period and the second action period can be executed in a period of a large number of human communications and a period of a small number of human communications in accordance with the activity cycle of the human society. Specifically, at the beginning of the next activity cycle, the first action can be performed again, and the inactivation of bacteria, fungi, and viruses in the environment can be performed continuously.

The first operating period may be set to day time, and the second operating period may be set to night time.

In the activity cycle of the human society, activities are active mainly during the day when the sun rises (6 o 'clock to 15 o' clock) as compared with the night when the sun falls (18 o 'clock to 3 o' clock), and people move to and from more places.

Therefore, by performing time control (timing control) of the first operation period and the second operation period in accordance with the activity cycle, it is possible to perform appropriate ultraviolet irradiation in accordance with the activity cycle of the human society. For example, the first operation period may be set to a time period of 5 to 15 points, and the second operation period may be set to a time period later than 15 points.

In addition, during the second operation period, an intermittent lighting operation may be performed in which the lighting operation of the light source unit and the turning-off operation of the light source unit are alternately performed.

This makes it possible to intermittently irradiate the adherent microorganisms, the existing location of which is fixed, with ultraviolet light, and to increase the cumulative irradiation amount for the adherent microorganisms even in a short period of time during the lighting operation.

In the above control, the illuminance (intensity) of the ultraviolet light emitted from the light source unit may be controlled to be higher in the second operation period than in the first operation period. Thereby, even in a short period of time during the lighting operation, ultraviolet rays can be effectively applied to the adhering microorganisms. In particular, the extinguishing action is performed upon sensing presence during the second action, and thus the inactivation effect in a shorter period of time is expected to be improved.

Further, the control unit may set a start time and an end time of the first operation period. In this way, by controlling the first operation period with the time (timer), the first operation period can be set to an appropriate time zone in the life cycle.

In addition, the control unit may perform control such that, in the first operation period, when a time period during which the presence of the person is not sensed by the sensing unit exceeds a predetermined reference time, the control unit stops the first operation period and starts a second operation period, based on a signal from the sensing unit.

In the above-described configuration, the sensing unit may include an image recognition unit, and the control unit may perform control such that, in the first operation period, when a time period during which the presence of the person is not sensed by the image recognition unit exceeds a predetermined reference time, the first operation period is stopped and a second operation period is started.

In this way, based on the result of the determination of whether or not a person is present by the sensing unit, it is possible to distinguish between an active time and an inactive time in the target space to which ultraviolet light is applied, and to switch to the first operation period when it is determined that the person is active, and to switch to the second operation period when it is determined that the person is inactive.

In addition, the amount of ultraviolet light per unit time in the period in which the presence of a person is not sensed in the first operation period may be controlled to be equal to the amount of ultraviolet light per unit time in the period in which the presence of a person is not sensed in the second operation period.

In this case, ultraviolet rays can be effectively applied to the attached microorganisms remaining on the surface of the object during the period in which the presence of a human is not sensed in the first operation period, and the inactivation effect can be improved.

In addition, an aspect of the ultraviolet irradiation method of the present invention is an ultraviolet irradiation method of controlling lighting of a light source unit including a light emission surface that emits ultraviolet rays having a wavelength band of 190nm to 235nm, the ultraviolet irradiation method including: a step of sensing the presence of a person; and a step of controlling lighting of the light source unit differently between a first operation period and a second operation period, wherein the second operation period is controlled such that ultraviolet rays are emitted from the light source unit when the presence of a person is not sensed, and the emission of ultraviolet rays is stopped when the presence of a person is sensed, and the amount of ultraviolet rays per unit time during a period in which the presence of a person is sensed in the first operation period is controlled to be smaller than the amount of ultraviolet rays per unit time during a period in which the presence of a person is not sensed in the second operation period.

Effects of the invention

According to one embodiment of the present invention, inactivation of microorganisms and/or viruses using ultraviolet light in a wavelength range in which adverse effects on the human body are suppressed can be performed efficiently and more appropriately.

Drawings

Fig. 1 is an external view schematically showing the ultraviolet irradiation apparatus according to the present embodiment.

Fig. 2 is an explanatory diagram relating to an operation example of the present embodiment.

Fig. 3 is an operation example of the first embodiment.

Fig. 4 shows another operation example of the second embodiment.

Fig. 5 shows an operation example of another embodiment.

Description of the reference numerals

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

Detailed Description

Hereinafter, embodiments of the present invention will be described with reference to the drawings.

Fig. 1 is an external view schematically showing an ultraviolet irradiation device 100 according to the present embodiment.

The ultraviolet irradiation apparatus 100 is an apparatus that inactivates microorganisms and viruses present in a space where humans and animals are present and on the surface of an object in the space by irradiating ultraviolet rays in the space.

Here, the space includes, for example, a space in an office, a commercial facility, a medical facility, a station facility, a school, a government, a theater, a hotel, a restaurant, or the like, and a space in a vehicle such as a car, a train, a bus, a taxi, an airplane, a ship, or the like. The space may be a closed space such as a ward, a meeting room, a toilet, or an elevator, or may be an unsealed space.

The ultraviolet irradiation apparatus 100 irradiates a target space with ultraviolet rays having a wavelength of 190 to 235nm (more preferably, ultraviolet rays having a wavelength of 200 to 230 nm) which has little adverse effect on cells of humans and animals, and inactivates harmful microorganisms and viruses present on the surface of an object or in the space in the target space. Here, the object includes a human body, an animal, and an object. The target space to which ultraviolet light is applied is not limited to a space in which humans and animals are actually present, and includes a space in which humans and animals are not present.

The term "inactivation" as used herein means the killing of microorganisms and viruses (or the loss of infectivity and toxicity).

As shown in fig. 1, the ultraviolet irradiation device 100 includes a light source unit that generates ultraviolet light, a control unit 16 that controls lighting of the light source unit, and a housing 11 that houses the light source unit and the control unit 16. The housing 11 has a light emission surface 12 for emitting ultraviolet light. Specifically, an opening 11a serving as a light exit window for emitting ultraviolet rays is formed. A window member made of, for example, quartz glass is provided in the opening 11a, and ultraviolet rays are emitted from the window member. In addition, a filter or the like for blocking light in an unnecessary wavelength band may be provided in the opening 11 a.

The ultraviolet irradiation device 100 is provided with a sensing unit 31 for sensing the presence of a person.

An excimer lamp 20 is housed as an ultraviolet light source in the housing 11. The excimer lamp 20 may be, for example, a KrCl excimer lamp emitting ultraviolet rays having a central wavelength of 222 nm. The ultraviolet light source is not limited to a KrCl excimer lamp, and may be any light source that emits ultraviolet light in a wavelength range of 190nm to 235 nm. Further, the housing 11 and the ultraviolet light source (excimer lamp 20) constitute a light source unit.

The UV radiation has a different penetrating power of cells depending on the wavelength, and the smaller the penetrating power is, the shorter the wavelength is. For example, UV radiation having a short wavelength of about 200nm passes through water very efficiently, but is absorbed by the outer parts (cytoplasm) of human cells to a large extent, and may not have enough energy to reach the nucleus containing DNA sensitive to UV radiation. Therefore, the above-mentioned UV radiation of short wavelength has less adverse effect on human cells. On the other hand, ultraviolet rays having a wavelength of more than 240nm may cause damage to DNA in the nucleus of a human body. In addition, ultraviolet light having a wavelength of less than 190nm is known to generate ozone.

Therefore, in the present embodiment, as the ultraviolet light source, an ultraviolet light source that emits ultraviolet light in a wavelength range of 190nm to 235nm that has little adverse effect on the human body and can obtain an inactivation effect and that emits substantially no UVC other than ultraviolet light is used. In addition, as a wavelength band having higher safety, an ultraviolet light source having a peak wavelength in a wavelength region of 200nm to 230nm may be used.

The excimer lamp 20 is provided with a discharge vessel 21 in the form of a straight tube hermetically sealed at both ends. The discharge vessel 21 is made of quartz glass, for example. In addition, a rare gas and a halogen are sealed as a light emitting gas in 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 emission light was 222 nm.

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

In fig. 1, the ultraviolet irradiation apparatus 100 includes a plurality of (3) discharge vessels 21, but the number of discharge vessels 21 is not particularly limited.

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

Furthermore, the discharge vessel 21 is arranged to contact and span the 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). By applying a high-frequency voltage between the first electrode 22 and the second electrode 23, the lamp is turned on.

The light extraction surface of the excimer lamp 20 is disposed opposite to the light exit window. Therefore, the light emitted from the excimer lamp 20 is emitted from the light emitting surface 12 of the ultraviolet irradiation device 100 through the light exit window.

Here, the

electrodes

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

The filter can be provided in the opening 11a serving as the light exit window as described above. The filter may be, for example, a wavelength selective filter which transmits light having a wavelength range of 190nm to 235nm (more preferably, light having a wavelength range of 200nm to 230 nm) with little adverse effect on the human body and cuts the UVC wavelength band having a wavelength of 236nm to 280 nm. Specifically, the ultraviolet illuminance at a wavelength of 236nm to 280nm is reduced to 1% or less with respect to the ultraviolet illuminance at a peak wavelength in a wavelength band of 190nm to 235 nm. As the wavelength selective filter, for example, a filter having HfO can be used₂Layer and SiO₂A dielectric multilayer film formed by the layers.

In addition, as the wavelength selective filter, a filter having SiO may be used₂Layer and Al₂O₃A dielectric multilayer film formed by the layers. Thus, by providing the filter at the light-exit window, even when the light harmful to human is emitted from the excimer lamp 20In this case, the light can be more reliably prevented from leaking out of the housing 11.

As shown in fig. 1, the ultraviolet irradiation 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 a power supply is supplied, and cooling components such as a radiator for cooling the power supply components. The control unit 16 controls the lighting of the excimer lamp 20 constituting the light source unit.

The sensing unit 31 may be a human body sensor that senses a human body present in a region (irradiation region) irradiated with ultraviolet rays emitted from the light emission surface 12. The motion sensor may be, for example, a pyroelectric infrared sensor that senses a change in heat (infrared rays) emitted from a human body or the like. When sensing the presence of a person, the sensing unit 31 transmits a sensing signal to the control unit 16.

Fig. 2 is an explanatory diagram showing an embodiment of the operation period of the present invention. Here, the first operation period is set to 8 to 16 points, for example, and the second operation period following the first operation period is set to 16 to 8 points (next morning). That is, the operation time was set to 8 hours.

The control unit 16 of the ultraviolet irradiation device 100 sets the start time (8: 00) and the end time (16: 00) of the first operation period, and the control unit 16 can perform timing control of the first operation period and the second operation period.

The start time and the end time of the first operation period are not limited to the above. The first operation period may be set to a time zone including the daytime during which the activity of the person is active (for example, a time zone of 5 to 15 o' clock). The operation time during the first operation is not limited to 8 hours.

In the present embodiment, the case where the start time and the end time of the first operation period are set in the control unit 16 and the control unit 16 performs the timer control of the first operation period and the second operation period has been described, but the user may instruct the start of the first operation period at an arbitrary timing. In this case, the control unit 16 sets an operable operation time (for example, 8 hours) in the first operation period, and the control unit 16 controls to start the second operation period after the first operation period ends. At this time, the operation time set in the first operation period is reset to the initial value after a time longer than the operation time elapses.

The first operation period is a period controlled to emit ultraviolet light regardless of the presence or absence of a person. This can maintain the effect of inactivating planktonic microorganisms (planktonic bacteria, viruses, and the like) floating in a space including humans.

The illuminance of ultraviolet rays to a person differs depending on the separation distance from the light-emitting surface 12. For example, if the ultraviolet irradiation device 100 is set on a ceiling, ultraviolet irradiation can be performed in a space in a state where the distance from the light emission surface 12 is kept equal to or greater than a predetermined value. On the other hand, since planktonic microorganisms present in the space are retained in the space, they are assumed to float in the vicinity of the light emission surface 12. In this case, ultraviolet rays with higher illuminance are irradiated to effectively deactivate the enzyme. That is, although the illuminance of ultraviolet light to a person is suppressed to a predetermined value, the chance of performing stronger ultraviolet irradiation on planktonic microorganisms can be secured.

In this way, during the first operation, the ultraviolet irradiation amount to the human is controlled so as not to exceed a predetermined upper limit, but an effect of inactivating planktonic microorganisms floating in the space can be expected. That is, in many cases, an effective inhibitory effect can be expected particularly against aerosol infection and droplet infection.

The second operation period is a lighting operation period performed after the first operation period ends (after a predetermined operation time has elapsed), and is a period in which the ultraviolet rays are efficiently irradiated to the attached microorganisms left behind by the human on the assumption of an unmanned environment. During the second operation, when the presence of a person is not sensed by the sensing unit 31, ultraviolet rays are emitted from the light source unit, and when the presence of a person is sensed by the sensing unit 31, the emission of ultraviolet rays is controlled to be stopped. That is, ultraviolet irradiation can be performed not for a person but for attached microorganisms left behind by the person.

In addition, the amount of ultraviolet light per unit time (the amount of ultraviolet light emitted) during the period in which the presence of a person is not sensed by the sensing unit 31 in the second operation period is set to be greater than the amount of ultraviolet light per unit time during the period in which the presence of a person is sensed by the sensing unit 31 in the first operation period. This enables efficient irradiation of ultraviolet light to a space other than a space including a person, such as bacteria and mold adhering to the surface of an object, and inactivation of the bacteria and mold.

In this way, the first operation period can be irradiated with ultraviolet light for a predetermined time in the space including the human, and the ultraviolet irradiation time for the human can be set to an appropriate range, and even after the first operation period is completed, the microorganisms adhering to the surface of the object in the space can be appropriately irradiated with ultraviolet light and inactivated in the second operation period.

Several embodiments of the ultraviolet irradiation apparatus 100 of the present invention will be described.

The first embodiment shows a case where the ultraviolet irradiation device 100 is installed on a ceiling, and the operation mode is set in advance according to the distance of separation between a place where people can move and the light emission surface 12. Here, a case where an intermittent lighting operation in which a lighting operation and a turning-off operation are alternately performed is shown. Table 1 shows the lighting operation pattern during the first operation.

[ TABLE 1 ]

As shown in table 1, a desired operation mode was selected according to the height of the ceiling, and ultraviolet irradiation was performed. For example, when a place separated from the light emitting surface 12 by a distance of 1.4m is set as a reference, the operation mode 1-2 is selected, and a lighting operation mode of 15 seconds lighting-200 seconds lighting-off is executed.

In addition, since ultraviolet irradiation to the person is assumed in the first operation period, it is preferable to set the lighting operation mode so that the ultraviolet irradiation amount to the person in the first operation period does not exceed the allowable limit value (TLV) of ACGIH.

Next, the lighting operation pattern in the period in which the presence of a person is not sensed in the second operation period is shown in table 2. In this period, as described above, the lighting operation mode is set to a lighting operation mode in which the ultraviolet ray amount per unit time is larger than the lighting operation mode in the first operation period.

[ TABLE 2 ]

Fig. 3 is a timing chart showing an operation example of the first embodiment. Fig. 3 shows a conceptual diagram, and the ON (ON) time and the OFF (OFF) time are different from those shown in tables 1 and 2.

As shown in fig. 3, at time t1 (8: 00), which is the start time of the first operation period, the control unit 16 of the ultraviolet irradiation device 100 selects an operation mode corresponding to the height of the ceiling from among the operation modes 1-1 to 1-4 in table 1, and executes the lighting operation mode of the selected operation mode. During this first operation, a certain lighting operation mode is continuously performed regardless of the presence or absence of a person.

Thereafter, at time t2 (16: 00), which is the end time of the first operation period, the control unit 16 ends the first operation period and starts the second operation period. At time t2, since the presence of a person is not sensed by sensing unit 31, the lighting operation mode of operation mode 2 in table 2 is executed. That is, the turn-off time is shortened as compared with the first operation period (time t1 to time t2) to increase the turn-on duty ratio of the intermittent turn-on.

When the presence of a person is detected at time t3 in the second operation period, the control unit 16 stops the emission of ultraviolet light from the light source unit. Thereafter, at time t4, if the presence of a person is not sensed again, the control unit 16 restarts ultraviolet irradiation. That is, the lighting operation mode of operation mode 2 is restarted.

In addition, from the viewpoint of energy saving, it is preferable that, even in the second operation period in which ultraviolet rays are efficiently irradiated to attached microorganisms left behind in a human being in an unmanned environment, the light source unit be controlled to stop the emission of ultraviolet rays when the presence of a human being is not sensed by the sensing unit 31 for 1 hour or more, preferably 2 hours or more (that is, when ultraviolet rays are sufficiently irradiated and sterilization is completed).

Next, a second embodiment will be explained. In this embodiment, an example of an operation mode in a case where the presence of a person is not sensed is added during the first operation. Four sections are set as the separation distance from the light emission surface 12, and different lighting operation modes (operation modes 1-1 to 1-4) can be selected for each section. Specific lighting actions are shown in table 3.

[ TABLE 3 ]

Here, during the first operation, if it is determined that the presence of a human being cannot be sensed by the sensing portion (human detecting sensor) 31 (in other words, if it is not present), the operation mode 1-0 can be set.

When the presence of a person is detected by the sensor unit 31, the lighting operation mode of the selected operation modes (1-1) to (1-4) is executed in accordance with the separation distance from the light emission surface 12.

For example, when a place separated from the light emitting surface 12 by a distance of 1.4m is set as a reference, the operation mode 1-2 is selected, and a lighting operation mode of 15 seconds lighting-200 seconds lighting-off is executed. When it is determined that the presence of a person cannot be sensed, the operation mode 1-0 is selected, and the lighting operation mode is executed in which the lighting operation mode is turned on for 15 seconds and turned off for 30 seconds. The extinguishing time here can be changed as appropriate, and for example, the extinguishing time may be set to 60 seconds to 15 seconds.

Next, the lighting operation pattern in the period in which the presence of a person is not sensed in the second operation period executed after the first operation period ends (after the elapse of the preset operation time) is shown in table 4. This period is set to a lighting operation mode in which the amount of ultraviolet light per unit time is larger than the lighting operation mode in the first operation period, as in the first embodiment described above. The operation pattern 2 in the second operation period may be controlled in the same manner as the non-existent pattern (operation pattern 1-0) in the first operation period.

[ TABLE 4 ]

Fig. 4 is a timing chart showing an operation example of the second embodiment. Fig. 4 shows a conceptual diagram, and the ON (ON) time and the OFF (OFF) time are different from those shown in tables 3 and 4.

As shown in fig. 4, at time t11 (8: 00) which is the start time of the first operation period, the presence of a person is sensed by the sensing unit 31, and therefore the control unit 16 of the ultraviolet irradiation device 100 selects an operation mode corresponding to the height of the ceiling from among the operation modes 1-1 to 1-4 in table 1, and executes the lighting operation mode of the selected operation mode.

When the presence of a person is no longer sensed at time t12 in the first operation period, control unit 16 selects operation mode 1-0 in table 1 and executes the lighting operation mode of operation mode 1-0. That is, the turn-off time is shortened and the turn-on duty ratio of the intermittent turn-on is increased as compared with the period (time t11 to t12) in which the presence of a person is sensed.

Thereafter, when the presence of a person is sensed again at time t13 in the first operation period, the control unit 16 selects an operation mode corresponding to the height of the ceiling from among the operation modes 1-1 to 1-4 in table 1, and executes the lighting operation mode of the selected operation mode. That is, the turn-off time is extended and the turn-on duty ratio of the intermittent turn-on is reduced as compared with the period (time t12 to t13) in which the presence of a human is not sensed.

Then, at time t14 (16: 00) which is the end time of the first operation period, the control unit 16 ends the first operation period and starts the second operation period. At time t14, since the presence of a person is not sensed, the lighting operation mode of operation mode 2 in table 2 is executed. That is, the intermittent lighting is performed at the same lighting duty ratio as that of the period (time t12 to t13, etc.) during which the presence of a person is not sensed in the first operation period.

The operation from time t14 onward is the same as the operation from time t2 onward in fig. 3.

In each of the above embodiments, based on the signal from the sensing unit 31, the control may be performed such that the first operation period is stopped and the second operation period is started after the first operation period is stopped when the presence of a person is not sensed by the sensing unit 31 for more than a predetermined reference time. The sensing unit 31 may include an image recognition unit, and control the first operation period to be stopped and the second operation period to be started when the time during which the presence of a person is not sensed by the image recognition unit exceeds a predetermined reference time. In the case where the ultraviolet irradiation device 100 includes a distance sensor capable of measuring a separation distance from an object facing the light emission surface 12, it may be controlled such that, when a time during which the separation distance between the object and the light emission surface 12 becomes equal to or longer than a predetermined distance exceeds a predetermined reference time based on a signal from the distance sensor, it is determined that the time during which the presence of a person is not sensed exceeds the predetermined reference time, the first operation period is stopped, and then the second operation period is started.

Fig. 5 is a timing chart showing an operation example in the case where the first operation period is stopped when the time during which the presence of a person is not sensed exceeds a predetermined reference time, and then the second operation period is started. Here, a case where the lighting operation mode shown in table 1 is executed in the first operation period will be described.

As shown in fig. 5, at time t21 (8: 00), which is the start time of the first operation period, the presence of a person is detected by the sensor unit 31, and therefore the control unit 16 of the ultraviolet irradiation device 100 selects an operation mode corresponding to the height of the ceiling from among the operation modes 1-1 to 1-4 in table 1, and executes the lighting operation mode of the selected operation mode.

When the presence of a human is no longer sensed at time t22 in the first operation period and the state continues, the controller 16 ends the first operation period at time t23 when a predetermined reference time has elapsed from time t22 and starts the second operation period. That is, at time t23, control unit 16 selects operation pattern 2 in table 2, and executes the lighting operation pattern of operation pattern 2.

Thus, the first operation period is ended at a timing earlier than the preset end time t24 (16: 00) of the first operation period, and the amount of ultraviolet rays emitted from the light source unit can be increased by moving to the second operation period. Thus, the inactivation effect can be further improved.

The operation from time t24 onward is the same as the operation from time t2 onward in fig. 3.

In the above embodiment, the turning-off time in the periodic turning-on/turning-off cycle is changed as the lighting operation pattern, but the operation pattern applied to the present invention is not limited to this. For example, the lighting time may be changed, or both the lighting time and the turning-off time may be changed, and control capable of changing the lighting duty ratio may be applied.

Further, the ultraviolet irradiation intensity is not limited to this, and the amount of ultraviolet rays emitted may be controlled in a predetermined interval by varying the ultraviolet irradiation intensity.

In the above embodiments, the case where the ultraviolet irradiation method by the light source unit is the intermittent lighting method has been described, but a continuous lighting method in which ultraviolet irradiation by the light source unit is continuously performed may be applied. In this case, the amount of ultraviolet light per unit time can be changed by changing the illuminance of the continuously lit ultraviolet light.

In the present invention, the "ultraviolet ray amount per unit time" means a value obtained by dividing the cumulative emission amount of ultraviolet rays in each lighting period (1 period) by the time of the 1 period, when the light source unit is periodically turned on and controlled by the control unit 16. For example, when one lighting cycle is constituted by a lighting time (ON time) and a lighting-OFF time (OFF time), the cumulative amount of ultraviolet radiation emitted during 1 cycle of the lighting cycle is divided by the total of the lighting time and the lighting-OFF time. That is, the "ultraviolet ray amount per unit time" corresponds to an average value of the cumulative amounts of ultraviolet rays emitted in the respective lighting periods.

In the case where the light source unit is not periodically turned on by the control unit 16 or in the case of a configuration in which the periodic lighting control cannot be performed, for example, in the case where only the continuous lighting control is performed at the time of lighting, the "ultraviolet ray amount per unit time" is set by dividing the cumulative ultraviolet ray emission amount within an arbitrarily set time (for example, 5 minutes, 10 minutes, or the like) by the set time (for example, 5 minutes, 10 minutes, or the like in the above example). In this case, the "ultraviolet ray amount per unit time" corresponds to an average value of the cumulative ultraviolet ray emission amounts in the continuous lighting operation. With the above, the magnitude of the ultraviolet ray amount in each operation period can be determined.

Claims

1. An ultraviolet irradiation apparatus, comprising:

a light source unit having a light emission surface that emits ultraviolet light having a wavelength band of 190nm to 235 nm;

a control unit that controls lighting of the light source unit; and

a sensing part for sensing the existence of a person,

the control unit includes a first operation period and a second operation period,

the second operation period is a period controlled as follows: emitting ultraviolet rays from the light source section when the presence of a person is not sensed by the sensing section, stopping the emission of the ultraviolet rays when the presence of a person is sensed by the sensing section,

the amount of ultraviolet light per unit time during a period in which the presence of a person is sensed in the first action period is controlled to be smaller than the amount of ultraviolet light per unit time during a period in which the presence of a person is not sensed in the second action period.

2. The ultraviolet irradiation apparatus according to claim 1,

an operable operation time during the first operation is set in the control unit,

the control unit performs control such that the second operation period is started after the first operation period is ended.

3. The ultraviolet irradiation apparatus according to claim 2,

the operation time set during the first operation is reset to an initial value after a time longer than the operation time has elapsed.

4. The ultraviolet irradiation apparatus according to any one of claims 1 to 3,

the first action period is set to day time, and the second action period is set to night time.

5. The ultraviolet irradiation apparatus according to any one of claims 1 to 3,

the first operation period is set to a time period of 5 to 15 points, and the second operation period is set to a time period later than 15 points.

6. The ultraviolet irradiation apparatus according to any one of claims 1 to 3,

during the second operation period, an intermittent lighting operation is performed in which the lighting operation of the light source unit and the turning-off operation of the light source unit are alternately performed.

7. The ultraviolet irradiation apparatus according to any one of claims 1 to 3,

the control unit sets a start time and an end time of the first operation period.

8. The ultraviolet irradiation apparatus according to any one of claims 1 to 3,

the control unit performs control such that, when the time during which the presence of a person is not sensed by the sensing unit exceeds a predetermined reference time during the first operation period, the control unit stops the first operation period and starts the second operation period, based on a signal from the sensing unit.

9. The ultraviolet irradiation apparatus according to any one of claims 1 to 3,

the sensing part is provided with an image recognition part,

the control unit performs control such that, in the first operation period, when the time during which the presence of a person is not sensed by the image recognition unit exceeds a predetermined reference time, the control unit stops the first operation period and starts the second operation period.

10. The ultraviolet irradiation apparatus according to any one of claims 1 to 3,

the amount of ultraviolet light per unit time during a period in which the presence of a person is not sensed in the first action period is controlled to be equal to the amount of ultraviolet light per unit time during a period in which the presence of a person is not sensed in the second action period.

11. An ultraviolet irradiation method for controlling lighting of a light source unit having a light emission surface that emits ultraviolet rays having a wavelength band of 190nm to 235nm, the ultraviolet irradiation method comprising:

a step of sensing the presence of a person; and

a step of controlling lighting of the light source section differently between the first operation period and the second operation period,

during the second operation period, the control unit performs control such that ultraviolet rays are emitted from the light source unit when the presence of a person is not sensed, and the emission of ultraviolet rays is stopped when the presence of a person is sensed,