WO2023073884A1

WO2023073884A1 - Ultraviolet light irradiation system

Info

Publication number: WO2023073884A1
Application number: PCT/JP2021/039887
Authority: WO
Inventors: 誉人桐原; 友宏谷口; 聖成川; 亜弥子岩城; 和秀中島; 隆松井; 裕之飯田; 千里深井; 悠途寒河江
Original assignee: 日本電信電話株式会社
Priority date: 2021-10-28
Filing date: 2021-10-28
Publication date: 2023-05-04

Abstract

The present invention aims to provide a P–MP ultraviolet light irradiation system that can obtain effects such as the impartial sterilization of each target irradiation area, ensure safety, and improve work efficiency.　The ultraviolet light irradiation system 301 according to the present invention is provided with: an ultraviolet light source unit 11 for generating ultraviolet light; N (where N is a natural number of at least 2) irradiation units 13 for irradiating N target irradiation areas AR with the ultraviolet light; an optical switch 12–2 for switching the path of the ultraviolet light to the paths 14 leading to the respective irradiation units 13; and a switching control unit 15–2 for setting the switching timing for the optical switch 12–2 on the basis of at least one out of the ultraviolet light transmission loss of each of the paths 14, the size of the irradiation area irradiated with ultraviolet light by the irradiation units 13, and the time required to deactivate the target irradiation areas AR.

Description

Ultraviolet light irradiation system

The present disclosure relates to an ultraviolet light irradiation system that uses ultraviolet light to sterilize and inactivate viruses.

Demand is increasing for systems that perform sterilization and virus inactivation using ultraviolet light for the purpose of preventing infectious diseases. There are three main categories of products in this system. In this specification, the term “sterilization, etc.” shall mean sterilization and virus inactivation.
(I) Mobile sterilization robot The product of Non-Patent Document 1 is an autonomous mobile robot that irradiates ultraviolet light. By irradiating the robot with ultraviolet light while moving in a room in a building such as a hospital room, the robot can automatically realize sterilization in a wide range without human intervention.
(II) Stationary air purifier The product of Non-Patent Document 2 is a device that is installed on the ceiling or at a predetermined place in a room, and performs sterilization while circulating the air in the room. Since the apparatus does not directly irradiate ultraviolet light and has no effect on the human body, highly safe sterilization is possible.
(III) Portable Sterilization Apparatus The product of Non-Patent Document 3 is a portable apparatus equipped with an ultraviolet light source. A user can bring the device to a desired area and irradiate it with ultraviolet light. Therefore, the device can be used in various places.

However, the device described in Non-Patent Document has the following problems.
(1) Economy Since the product of Non-Patent Document 1 is irradiated with high-output ultraviolet light, the apparatus becomes large and expensive. Therefore, the product of Non-Patent Document 1 has a problem that it is difficult to realize an economical system.
(2) Versatility In the product of Non-Patent Document 1, since the ultraviolet light irradiation position is limited to a place where the robot can move/enter, it is difficult to irradiate the ultraviolet light to a small place or a deep place.
Since the product of Non-Patent Document 2 sterilizes the circulated indoor air, it is not possible to directly irradiate ultraviolet light to a place to be sterilized.
The product of Non-Patent Document 3, for example, cannot irradiate ultraviolet light to narrow pipes or areas where people cannot enter.
Thus, the product of Non-Patent Literature has a problem of versatility in that it can irradiate any place with ultraviolet light.
(3) Operability The product of Non-Patent Document 3 is portable and can be irradiated with ultraviolet light at various locations. However, in order to obtain sufficient effects such as sterilization at the target location, the user is required to have skill and knowledge, and there is a problem in operability.

For these problems, an ultraviolet light irradiation system 300 using an optical fiber as shown in FIG. 1 is conceivable. This ultraviolet light irradiation system transmits ultraviolet light from the light source 11 using a thin and flexible optical fiber, and irradiates the ultraviolet light output from the tip of the optical fiber 14 to an irradiation target area AR to be sterilized or the like with pinpoint accuracy. . The versatility of the above problem (2) can be solved because the ultraviolet light can be irradiated to any place simply by moving the irradiation unit 13 at the tip of the optical fiber 14 . In addition, since there is no need to move or set the ultraviolet light source, and the user is not required to have skills or knowledge, the operability of the above problem (3) can be resolved. Furthermore, by providing an optical distribution unit 12 such as an optical splitter in the optical transmission line 16 to form a P-MP (Point to MultiPoint) system configuration such as FTTH (Fiber To The Home), a single light source can be used. By sharing, you can sterilize multiple places. Therefore, it is possible to solve the problem (1) economically.

However, there are the following problems in realizing the P-MP configuration as an ultraviolet light irradiation system.
The length of the optical fiber 14, the area of the irradiation target area AR, and the illuminance required for the irradiation target area AR (illuminance required for sterilization or the like) are different. However, the light distribution unit 12 provided in the ultraviolet light irradiation system 300 as shown in FIG. fiber) with equal power split. In this specification, the energy of ultraviolet light considering the time to be supplied to each direction and the energy of ultraviolet light considering the time to irradiate the irradiation target area AR is the integrated light amount (unit: J). The energy per unit time is defined as power (unit: W), and the power per unit area of the ultraviolet light applied to the irradiation target area AR is defined as illuminance (W/m ² ).
(A) Fairness Each path 14 has a different transmission loss depending on the length of the optical fiber and the distance from the irradiation unit to the irradiation target area, and the area of the irradiation target area AR is also different. However, since the light distribution unit 12 of the ultraviolet light irradiation system 300 power-splits the ultraviolet light at an equal splitting ratio, it is difficult to obtain uniform illuminance in each irradiation target area AR. In other words, the ultraviolet light irradiation system 300 has a problem that it is difficult to obtain a fair sterilization effect in each irradiation target area AR.
(B) Safety Each route 14 has a different transmission loss depending on the length of the optical fiber and the distance from the irradiation unit to the irradiation target area, and the area of the irradiation target area AR is also different. However, since the light distribution unit 12 of the ultraviolet light irradiation system 300 power-splits the ultraviolet light at an equal splitting ratio, there is a case where the irradiation target area AR is irradiated with the ultraviolet light with excessive illuminance. In other words, depending on the configuration, the ultraviolet light irradiation system 300 may be irradiated with ultraviolet light having an excessive illuminance, which poses a problem of difficulty in ensuring safety.
(C) Efficiency Further, in the irradiation target area AR, there are places where sterilization, etc., should be completed in a short period of time with increased illuminance, and places where sterilization, etc., should be performed for a long time with ultraviolet light with reduced illuminance. However, since the light distribution unit 12 of the ultraviolet light irradiation system 300 power-splits the ultraviolet light at an equal splitting ratio, it is difficult to supply the ultraviolet light with the illuminance desired for each irradiation target area AR. In other words, the ultraviolet light irradiation system 300 cannot perform sterilization or the like by a method according to the irradiation target area AR, and has a problem that it is difficult to improve the working efficiency.

In order to solve these problems, the present invention is a P-MP configuration that can obtain effects such as fair sterilization in each irradiation target area, can ensure safety, and can improve work efficiency. It is an object of the present invention to provide an ultraviolet light irradiation system of

In order to achieve the above object, the ultraviolet light irradiation system according to the present invention comprises an optical switch for distributing ultraviolet light to each route, and the switching timing of the optical switch (the cumulative amount of ultraviolet light distributed to each route) is ) was adjusted.

Specifically, the ultraviolet light irradiation system according to the present invention includes:
an ultraviolet light source that generates ultraviolet light;
N irradiating units that irradiate N (N is a natural number of 2 or more) irradiation target areas with the ultraviolet light;
an optical switch that switches the ultraviolet light to a direction to each of the irradiation units;
Setting the switching timing of the optical switch based on at least one of the transmission loss of the ultraviolet light for each of the routes, the irradiation area where the irradiation unit irradiates the ultraviolet light, and the required time for deactivation of the irradiation target area. a switching control unit;
Prepare.

This ultraviolet light irradiation system employs an optical switch as a light distribution unit that distributes the ultraviolet light transmitted from the ultraviolet light source unit to multiple single-core optical fibers. The switching timing of the optical switch is changed according to the conditions of the irradiation target area. Specific switching timings are as follows.

The switching timing is based on the transmission loss of the ultraviolet light for each of the routes and the irradiation area where the irradiation unit irradiates the ultraviolet light, so that the integrated light amount per unit area to each irradiation target area is uniform. This is the timing at which the ultraviolet light is supplied. The aforementioned problem (A) can be solved.

The switching control unit is characterized by setting the switching timing so that the integrated light quantity of the ultraviolet light irradiated to each of the irradiation target areas is equal to or less than a predetermined reference value. The aforementioned problem (B) can be solved.

The switching control unit is characterized in that the switching timing is set so as to satisfy the integrated light quantity of the ultraviolet light required by each of the irradiation target areas. The aforementioned problem (C) can be solved.

Therefore, the present invention provides an ultraviolet light irradiation system with a P-MP configuration that can obtain effects such as fair sterilization in each irradiation target area, can ensure safety, and can improve work efficiency. can do.

Moreover, even when light is distributed by an optical switch, the following problem arises if the route is switched at a constant timing to distribute the ultraviolet light.
Problem (D): The switching timing of the optical switch is set in accordance with the irradiation target area where sterilization or the like is performed intensively (the integrated light quantity of ultraviolet light is the largest). With this setting, ultraviolet light with the same power is distributed to all the output ports, and the number of branches (the number of irradiation target areas) is limited depending on the power of the ultraviolet light output from the ultraviolet light source section. For this reason, there is a problem that it is difficult to increase the effect of splitting the cost of the ultraviolet light source unit and the optical switch (to reduce the cost of the ultraviolet light source unit and the optical switch which are borne by one irradiation target area).
Problem (E): The power (maximum power) of the ultraviolet light output by the ultraviolet light source unit is set in accordance with the irradiation target area where sterilization is to be performed strongly (the cumulative amount of ultraviolet light is the largest). With this setting, ultraviolet light with the maximum power is distributed to all the output ports, so there is a problem that it is difficult to reduce the power consumption of the ultraviolet light source section.

There are two ways to solve the problems (D) and (E).
(Means 1) If the direction is switched at a constant timing, the energy of the ultraviolet light may become excessive depending on the irradiation target area. Therefore, as described above, the switching timing of the optical switch (integrated amount of light) is optimized according to the transmission loss up to each irradiation target area and the area of the irradiation target area.
(Means 2) If the direction is switched at a constant timing, the energy of the ultraviolet light may become excessive depending on the irradiation target area. Therefore, in order to change the power of the ultraviolet light for each irradiation target area, a light source control section is further provided which changes the power of the ultraviolet light with respect to the ultraviolet light source section in conjunction with the switching operation of the optical switch.

By these means, it is possible to avoid supplying ultraviolet light of excessive power to the irradiation target area, relax the limit on the number of branches, improve the effect of splitting the bill, and reduce the power consumption of the ultraviolet light source. . Therefore, this ultraviolet light irradiation system can solve the above problems (D) and (E).

Furthermore, since the ultraviolet light irradiation system according to the present invention employs an optical switch as a substitute for the light distribution unit 12 in FIG. Even if the conditions of (such as performing sterilization in a short time or performing sterilization in a long time) change after the fact, there is also the advantage that the switching timing can be adjusted according to the conditions after the change. .

Further, in the ultraviolet light irradiation system 300 of FIG. 1, the ultraviolet light source section 11 and the light distribution section 12 may be arranged at the same place or arranged in the same housing. In the case of such a configuration, the following problems also occur.

Problem (F): Since the route of the optical fiber is laid from the vicinity of the ultraviolet light source to each irradiation target area, the total length of the optical fiber becomes long according to the number of irradiation target areas AR, and the cost of system members and construction. There is a problem that the

Therefore, the ultraviolet light irradiation system according to the present invention preferably separates the ultraviolet light source section and the optical switch, and further includes an optical transmission line connecting the ultraviolet light source section and the optical switch.

In this ultraviolet irradiation system, the optical switch is installed near the irradiation target area, so the optical fiber in the section from the ultraviolet light source to the optical switch can be shared, and the total length of the optical fiber can be shortened. For this reason, the cost of members and construction can be reduced by the amount that the optical fiber can be shared, and the problem (F) can be solved.

The above inventions can be combined as much as possible.

The present invention provides an ultraviolet light irradiation system with a P-MP configuration that can obtain effects such as fair sterilization in each irradiation target area, can ensure safety, and can improve work efficiency. can be done.

It is a figure explaining the subject of this invention. It is a figure explaining the ultraviolet light irradiation system which concerns on this invention. It is a figure explaining the cross-sectional structure of an optical fiber. It is a figure explaining the switching timing in the optical switch of the ultraviolet light irradiation system which concerns on this invention. It is a figure explaining the ultraviolet light irradiation system which concerns on this invention. It is a figure explaining the switching timing in the optical switch of the ultraviolet light irradiation system which concerns on this invention. It is a figure explaining the ultraviolet light irradiation system which concerns on this invention. It is a figure explaining the switching timing in the optical switch of the ultraviolet light irradiation system which concerns on this invention. It is a figure explaining the effect of the ultraviolet light irradiation system which concerns on this invention. It is a figure explaining the ultraviolet light irradiation system which concerns on this invention. It is a figure explaining the effect of the ultraviolet light irradiation system which concerns on this invention. It is a figure explaining the effect of the ultraviolet light irradiation system which concerns on this invention. It is a flowchart explaining the ultraviolet-light irradiation method of the ultraviolet-light irradiation system which concerns on this invention.

An embodiment of the present invention will be described with reference to the attached drawings. The embodiments described below are examples of the present invention, and the present invention is not limited to the following embodiments. In addition, in this specification and the drawings, constituent elements having the same reference numerals are the same as each other.

(Embodiment 1)
FIG. 2 is a diagram illustrating the ultraviolet light irradiation system 301 of this embodiment. The ultraviolet light irradiation system 301 is
an ultraviolet light source unit 11 that generates ultraviolet light;
N irradiating units 13 that irradiate N (N is a natural number of 2 or more) irradiation target areas AR with the ultraviolet light;
an optical switch 12-2 that switches the ultraviolet light to a route 14 to each of the irradiation units 13;
The switching timing of the optical switch 12-2 is determined based on at least one of the transmission loss of the ultraviolet light for each route 14, the irradiation area irradiated with the ultraviolet light by the irradiation unit 13, and the required time for deactivation of the irradiation target area AR. a switching control unit 15-2 for setting;
Prepare.

The ultraviolet light source unit 11 outputs light in the ultraviolet region (ultraviolet light) that is effective for sterilization and the like. Let P [W] be the power of the ultraviolet light output by the ultraviolet light source unit 11 . The ultraviolet light source section 11 and the optical switch 12-2 are connected by an optical transmission line 16, which is an optical fiber or space.

The optical switch 12-2 outputs the ultraviolet light from the ultraviolet light source section 11 to any one of the plurality of output ports according to the instruction from the switching control section 15-2. Here, the time required for path switching in the optical switch 12-2 is T _sw [s]. The ultraviolet light output from the output ports 1 to N is irradiated to the irradiation target areas AR (1 to N) via the route 14 and the irradiation unit 13, respectively.

The route 14 propagates the ultraviolet light intermittently distributed by the optical switch 12 - 2 to each irradiation section 13 . Path 14 is an optical fiber. Since it is an optical fiber, it can be installed in narrow places where conventional robots and devices cannot enter. FIG. 3 is a diagram illustrating a cross section of an optical fiber that can be used for the optical transmission line 16 and the path 14 of the optical fiber.
(1) Solid Core Optical Fiber This optical fiber has one solid core 52 in the clad 60 having a higher refractive index than the clad 60 . "Full" means "not hollow". The solid core can also be realized by forming an annular low refractive index region in the clad.
(2) Hole-assisted optical fiber This optical fiber has a solid core 52 in the clad 60 and a plurality of holes 53 arranged around the core. The medium of the holes 53 is air, and the refractive index of air is sufficiently smaller than that of quartz-based glass. Therefore, the hole-assisted optical fiber has a function of returning light leaking from the core 52 due to bending or the like back to the core 52, and is characterized by a small bending loss.
(3) Hole structure optical fiber This optical fiber has a hole group 53a of a plurality of holes 53 in the clad 60, and has an effective refractive index lower than that of the host material (glass or the like). This structure is called a photonic crystal fiber. This structure can take a structure in which a high-refractive-index core with a changed refractive index does not exist, and light can be confined using the region 52a surrounded by the holes 53 as an effective core region. Compared to optical fibers with solid cores, photonic crystal fibers can reduce the effects of absorption and scattering losses due to additives in the core. Optical characteristics that cannot be realized can be realized.
(4) Hollow core optical fiber This optical fiber has a core region made of air. Light can be confined in the core region by adopting a photonic bandgap structure with a plurality of holes or an anti-resonant structure with glass wires in the cladding region. This optical fiber has low nonlinear effects and is capable of delivering high power or high energy lasers.
(5) Coupling Core Optical Fiber In this optical fiber, a plurality of solid cores 52 having a high refractive index are closely arranged in a clad 60 . This optical fiber guides light by optical wave coupling between solid cores 52 . Coupling-core type optical fibers can disperse and transmit light as many times as the number of cores, so high power can be used for efficient sterilization. There is an advantage that the service life can be extended.

The irradiation unit 13 irradiates the ultraviolet light transmitted through the route 14 to a predetermined target location (irradiation target area AR) for sterilization or the like. The irradiation unit 13 is composed of an optical system such as a lens designed for the wavelength of ultraviolet light.

The switching control unit 15-2 controls the optical switch 12-2 to repeat the operation of giving each path 14 (output ports 1 to N of the optical switch) an opportunity to supply ultraviolet light for a period of time T, respectively. FIG. 4 is a diagram illustrating an example of switching control of the optical switch 12-2 performed by the switching control unit 15-2. This control is an operation when the transmission loss of ultraviolet light to the irradiation target area AR is equal to the irradiation area. Let the time T be the time obtained by the formula (1).

Here, E [W·s/m ² ] is the amount of ultraviolet light per unit area (integrated amount of light) required for sterilization or the like. Also, the loss from the ultraviolet light source unit 11 to the irradiation unit 13 (including the transmission loss of the optical switch 12-2) is L _fiber [a. u. ], and the loss from the irradiation unit 13 to the irradiation target area AR is L _air [a. u. ]. Also, let S [m ² ] be the area of the spot of the ultraviolet light irradiated to the irradiation target area AR.

By operating the optical switch 12-2 in this way and supplying the ultraviolet light at the opportunity, the ultraviolet light amount E [W s/m ² ] can be irradiated. In other words, the ultraviolet light irradiation system 301 can ensure the effect of sterilization and the like for each irradiation target area AR every time T _inact [s] of Expression (2).

Further, the switching control unit 15-2 controls the optical switch 12-2 so that the time of the opportunity to supply ultraviolet light to each output port is T/M [s] (M is a natural number of 2 or more). However, the same effect can be obtained.

5 and 6 are diagrams for explaining a case where switching timings different from those in FIGS. 2 and 4 are set in the optical switch 12-2. 5 and 6 show cases where the transmission loss of ultraviolet light to the irradiation target area AR and the irradiation area are different. The ultraviolet light irradiation system 301 shown in FIG. 5 has the same structure as the ultraviolet light irradiation system 301 shown in FIG. In this embodiment, only parts different from FIGS. 2 and 4 will be described.

For example, the switching control unit 15-2 of the present embodiment directs the ultraviolet light from the ultraviolet light source unit 11 to the optical switch 12-2 so that the illuminance of the ultraviolet light irradiated to each irradiation target area AR becomes equal. divide the time. Specifically, the switching timing is set to give an opportunity to supply ultraviolet light as follows.
(a1) The switching timing is such that the ultraviolet light is supplied for a long time to the irradiation target area AR having a large area and the ultraviolet light supply time to the irradiation target area AR having a small area is short. The illuminance of the ultraviolet light to each irradiation target area AR becomes uniform, and effects such as fair sterilization can be obtained.
(a2) The distance of the route 14 and the distance from the irradiation unit 13 to the irradiation target area AR are long, the ultraviolet light supply time to the irradiation target area AR is long, and the irradiation from the irradiation unit 13 is long. The switching timing is set such that the ultraviolet light supply time to the irradiation target area AR having a short distance to the target area AR and a small transmission loss is short. The illuminance of the ultraviolet light to each irradiation target area AR becomes uniform, and effects such as fair sterilization can be obtained.
(a2′) When the areas of the irradiation target areas AR are different as shown in FIG. The switching timing should be such that the sterilization becomes uniform and effects such as fair sterilization can be obtained.

Let P [W] be the power of the ultraviolet light output by the ultraviolet light source unit 11 . Let T _sw [s] be the time required for path switching in the optical switch 12-2. L _fiber-1 [a. u. ], and L _fiber-2 [a. u. ], . . . , L _fiber-N [a. u. ]. Let L _air−1 [a. u. ], L _air-2 [a. u. ], . . . , L _air-N [a. u. ]. Also, let the areas of the ultraviolet light spots irradiated onto the irradiation target areas AR be S ₁ [m ² ], S ₂ [m ² ], . . . , _SN [m ² ].

FIG. 6 is a diagram for explaining switching control of the optical switch 12 performed by the switching control unit 15-2. This control is an operation when the transmission loss of the ultraviolet light to the irradiation target area AR and the irradiation area are different.
The switching control unit 15-2 repeats the operation of giving the optical switch 12-2 an opportunity to supply ultraviolet light to each output port i (i=1, 2, . . . , N) for the time T _i . Control. Let T _i be the time obtained by equation (3).

Here, E [W·s/m ² ] is the amount of ultraviolet light required for sterilization or the like.

By operating the optical switch 12-2 in this way and supplying the ultraviolet light at the opportunity, the ultraviolet light amount E [W s/m ² ] can be irradiated. That is, the ultraviolet light irradiation system 301 can ensure the effect of sterilization and the like for each irradiation target area AR every time T _inact [s] of Expression (4).

Further, the switching control unit 15-2 sets the time of the opportunity to supply the ultraviolet light to each output port of the optical switch 12-2 to T _i /M [s] (M is a natural number of 2 or more). A similar effect can be obtained by controlling.

In addition, when a person enters and exits the irradiation target area AR, it is necessary to avoid irradiating the person with excessive ultraviolet light. In this case, the switching control section 15-2 sets the switching timing in the optical switch 12-2 so that the integrated amount of the ultraviolet light applied to each irradiation target area AR is equal to or less than a predetermined reference value. Specifically, the branch ratio is set as follows.
(b1) The illuminance of ultraviolet light should be 6.0 mJ/cm2 ^or less (0.2 μW per unit time) within 8 hours per day in order to safely sterilize by reducing the amount of exposure to humans. /cm ² ) is a standard value (JISZ8812). For this reason, the ultraviolet light power output from the ultraviolet light source unit 11, the loss L _fiber-n [a. u. ], loss L _air-n [a. u. ], and the area S _n [m ² ], calculate T and Ti such that the illuminance of the ultraviolet light irradiated to each irradiation target area AR is less than the reference value, and use it as a switching timing .

When a person enters and exits the irradiation target area AR, sterilization can be performed by setting the switching timing of the optical switch 12-2 in this way, and the irradiation target area AR is irradiated with ultraviolet light of excessive illuminance. can be prevented, and the safety of the ultraviolet light irradiation system 301 can be ensured.

FIGS. 7 and 8 are also diagrams for explaining a case in which switching timings different from those in FIGS. 2 and 4 are set in the optical switch 12-2. 7 and 8 show the case where the switching timing is set so as to satisfy the integrated quantity of ultraviolet light required by each irradiation target area AR. Specifically, the switching timing is set as follows.
(a3) Increase the integrated light intensity to the irradiation target area AR2 where strong sterilization is desired (long supply time _T2 ), and decrease the integrated light intensity to the irradiation target area ARN that does not require strong sterilization (supply time shorten _TN ). The requirements of each irradiation target area AR can be fairly met, and effects such as fair sterilization can be obtained.
(c1) Increase the integrated amount of light to the irradiation target area AR2 that requires sterilization etc. in a short time (longer the supply time _T2 ), and decrease the integrated amount of light to the irradiation target area ARN to perform sterilization etc. over time ( Shorten the supply time _TN ). A large amount of ultraviolet light can be distributed to the desired irradiation target area AR, and sterilization and the like can be performed in a short period of time. On the other hand, the supply of ultraviolet light to other irradiation target areas AR is reduced, and sterilization or the like is performed over time.

By setting such a switching timing in the optical switch 12-2, it is possible to respond to requests such as sterilization of the irradiation target area AR (for a short time or a long time), and improve the efficiency of the ultraviolet light irradiation system 301. be able to.
Examples of irradiation target areas AR for long-term sterilization include rooms where exposure to high-intensity ultraviolet light is to be avoided (places where people and animals come and go) and the intake/outlet of air-conditioning equipment. can. Examples of the irradiation target area AR that performs sterilization or the like in a short time include a closed space such as a UV sterilization box that does not allow people or animals to enter.

Alternatively, the switching timing of the optical switch 12-2 may be set by combining the branching ratio setting methods (a1), (a2), (a2′), (a3), (b1) and (c1). .

The switching control unit 15-2 changes the switching timing of the optical switch 12-2 as shown in FIGS. effect is also obtained.

FIG. 9 is a diagram explaining this effect. FIG. 9A is a diagram for explaining an example in which the optical switch 12-2 supplies ultraviolet light to each route 14 at equal switching timing regardless of the length of the route 14 and the request for the irradiation target area AR. be. FIG. 9B shows this ultraviolet light irradiation system, and is a diagram for explaining an example in which the optical switch 12-2 supplies ultraviolet light to each route 14 at unequal switching timings.

As described above, it is necessary to allocate a large amount of energy to the irradiation target area AR having a large transmission loss due to the long transmission distance of the route 14 and to the irradiation target area AR having a large area in order to enable sterilization or the like. In addition, the required energy also changes depending on the required time for deactivation of the irradiation target area AR. The required inactivation time is the time required to satisfy the desired inactivation rate (the ratio of bacteria before irradiation to the state after irradiation, or the ratio of viruses between the state before irradiation and after irradiation). means
As described above, the ultraviolet light irradiation system 301 adjusts the energy of the ultraviolet light according to the ultraviolet light supply time (integrated light amount) determined by the switching timing of the optical switch 12-2.

When distributing the ultraviolet light with uniform switching timing as shown in FIG. Energy that matches the required route is supplied to all routes. Then, when the number of routes is increased, if the switching timing period T _inact is the same, the ultraviolet light supply time (T, T _i ) to each route is reduced, and the route requiring the maximum energy There is also the possibility that the energy of the ultraviolet light supplied to the system is insufficient. If the period T _inact cannot be changed and the power of the ultraviolet light that can be output by the ultraviolet light source unit 11 cannot be increased, the number of routes must be limited if the ultraviolet light is distributed at uniform switching timing. There is also a problem that the splitting effect of the ultraviolet light source units 11 and the optical switches 12-2 due to the number is limited.

On the other hand, if the optical switch 12-2 distributes the ultraviolet light at uniform switching timing, a route with a small transmission loss, a route with a small irradiation target area AR, a route with a long deactivation request time, etc. A route with sufficient energy will be supplied with excess energy ultraviolet light. Therefore, as described with reference to FIGS. 5 to 8, the ultraviolet light is distributed by changing the switching timing of the optical switch 12-2 according to the transmission loss, the area of the irradiation target area AR, or the required deactivation time. Specifically, the ultraviolet light supply time is shortened for a route requiring a small amount of energy, and the ultraviolet light supply time is lengthened for a route requiring a large amount of energy. By setting the switching timing of the optical switch according to the characteristics of each route in this way, the above-described energy shortage can be resolved, and the restriction on the number of routes can be relaxed (FIG. 9B). As a result, it is possible to improve the splitting effect of the ultraviolet light source unit 11 and the optical switch 12-2 depending on the number of routes.

(Embodiment 2)
FIG. 10 is a diagram illustrating the ultraviolet light irradiation system 302 of this embodiment. Here, only differences from the ultraviolet light irradiation system 301 described in the first embodiment will be described. The ultraviolet light irradiation system 302 further includes a light source control unit 17 that changes the power of the ultraviolet light with respect to the ultraviolet light source unit 11 so as to interlock with the switching operation of the optical switch 12-2 for the ultraviolet light irradiation system 301. .

The light source control unit 17 is preset with an ultraviolet light power corresponding to the characteristics of each route 14 . The ultraviolet light power corresponding to the characteristics of each route is the power corresponding to the transmission loss, the area of the irradiation target area AR, and the required deactivation time.
The light source control unit 17 obtains information from the switching control unit 15-2 as to which path 14 the ultraviolet light is being output to at the current time. Based on the information, the light source control unit 17 causes the ultraviolet light source unit 11 to output the power of the ultraviolet light set for the route 14 at the current time.

FIG. 11 is a diagram explaining the effect of the ultraviolet light irradiation system 302. FIG. In FIG. 11A, similarly to FIG. 9A, regardless of the length of the path 14 and the request for the irradiation target area AR, ultraviolet light of the same power is distributed to each path 14 at equal switching timing. It is a figure explaining an example. FIG. 11(B) is an ultraviolet light irradiation system 302, and is a diagram for explaining an example in which ultraviolet light of different power is distributed to each path 14 at equal switching timings.

As described above, when the transmission distance of the route 14 is long and the transmission loss is large, or when the irradiation target area AR is wide and the illuminance is low, it is necessary to distribute a large amount of energy. In addition, the required energy also changes depending on the required time for deactivation of the irradiation target area AR. The ultraviolet light irradiation system 302 adjusts the energy of the ultraviolet light with the power of the ultraviolet light output by the ultraviolet light source section 11 .

When the ultraviolet light is distributed at equal switching timings as shown in FIG. 11(A), the ultraviolet light source unit 11 supplies ultraviolet light with a power that matches the route requiring the maximum energy. Then, excessive energy will be supplied to the route where small energy is sufficient. Therefore, depending on the route 14, the energy of the ultraviolet light must be wasted, and the power consumption of the ultraviolet light source unit 11 is also wasted. For this reason, when distributing ultraviolet light with equal switching timing and the same power, it is difficult to reduce the power consumption of the ultraviolet light source unit 11 .

Therefore, as described with reference to FIGS. 5 to 8, the ultraviolet light source unit 11 outputs ultraviolet light while changing the power according to the transmission loss, the area of the irradiation target area AR, or the required deactivation time. The ultraviolet light source unit 11 reduces the power of the ultraviolet light when the optical switch 12-2 is connected to a route that requires a small amount of energy, and connects the optical switch 12-2 to a route that requires a large amount of energy. increase the power of the ultraviolet light. As a result, the wasteful supply of ultraviolet light as described above can be eliminated, and the power consumption of the ultraviolet light source section 11 can be reduced (FIG. 11(B)). As a result, power saving of the ultraviolet light irradiation system can be achieved.

The switching timing of the optical switch 12-2 of the ultraviolet light irradiation system 302 may be set in combination with the switching timing of the optical switch 12-2 described in the ultraviolet light irradiation system 301 of the first embodiment.

(Embodiment 3)
FIG. 12 is a diagram illustrating the ultraviolet light irradiation system 303 of this embodiment. Here, only differences from the ultraviolet light irradiation system 301 described in the first embodiment will be described. In the ultraviolet light irradiation system 303 of this embodiment, the ultraviolet light source unit 11 and the optical switch 12-2 are separated, and an optical transmission line (optical fiber) 26 connecting the ultraviolet light source unit 11 and the optical switch 12-2 is further provided. The optical fiber described with reference to FIG. 3 can be used for the optical transmission line 26 .

FIG. 12 is a diagram explaining the effect of this embodiment. The term “separate” means that the ultraviolet light source section 11 and the optical switch 12-2 are not located at the same place or are not in the same housing 3. FIG.

In the ultraviolet light irradiation system 301 of FIG. 12(A), the optical switch 12-2 distributes the ultraviolet light to each route 14 and propagates it to each irradiation target area AR, as described above. The ultraviolet light source section 11 and the optical switch 12-2 are arranged in the same place (for example, in one housing 3). Therefore, the optical fiber that is the route 14 must be laid to each irradiation target area AR, and the total extension of the optical fiber becomes longer according to the number of irradiation target areas AR, resulting in the cost of system members and construction. can be higher.

　On the other hand, the ultraviolet light irradiation system 303 of FIG. For this reason, the ultraviolet light irradiation system 303 does not place the optical switch 12-2 in the same housing as the ultraviolet light source unit 11, but protrudes to the vicinity of the irradiation target area AR, and from there on the route 14 each irradiation target area AR UV light can be supplied to the The optical fiber 26 has a length that covers a section from the ultraviolet light source unit 11 to the irradiation target area AR, such as a room or equipment, and has a length of 10 m or more, for example. In short, the ultraviolet light irradiation system 303 connects the ultraviolet light source unit 11 and the optical switch 12-2 that are not in the same place or in the same housing by the optical fiber 26, and connects the optical switch 12-2 to the ultraviolet light source unit 11. The feature is that it can be placed in different places.

The configuration of the ultraviolet light irradiation system 303 produces the following effects. In this configuration, only one long optical fiber 26 and a short optical fiber between the optical switch 12-2 and the irradiation unit 13 are laid. Therefore, even if the number of irradiation target areas AR increases, the total extension of the optical fibers is not as long as that of the ultraviolet light irradiation system 301, and the cost of system members and construction increases according to the number of irradiation target areas AR. can be avoided.

In this way, the ultraviolet light irradiation system 303 can avoid an increase in the total length of the optical fibers due to an increase in the number of irradiation target areas AR, and can reduce the cost. Specific examples are described below.
Let X (m) be the length of the optical transmission line (optical fiber) 16, Y (m) be the length of the optical transmission line (optical fiber) 26, and N be the number of branches in the optical switch 12-2. Compared with the ultraviolet light irradiation system 301, the ultraviolet light irradiation system 303 has
(Y - X) x (N - 1) (m)
can shorten the total length of the optical fiber.
As an example, if X=1 (m), Y=10 (m), and N=10,
(10-1) x (10-1) = 81 (m)
As a result, the total length of the optical fiber can be reduced by 81 (m).

In the ultraviolet light irradiation system 303, the switching control section 15-2 described in the first and second embodiments can be arranged near the ultraviolet light source section 11. With this configuration, the switching timing of the optical switch 12-2 can be remotely controlled from the ultraviolet light source unit 11 side. Also, the switching controller 15-2 may be located near the optical switch 12-2. An operator can set the switching timing near the optical switch 12-2.

In this way, compared to the ultraviolet light irradiation system 301, the ultraviolet light irradiation system 303 can avoid an increase in the total extension of the optical fibers due to an increase in the number of irradiation target areas AR, and can reduce costs. Although the ultraviolet light irradiation system 303 and the ultraviolet light irradiation system 301 have been described in the present embodiment, similar effects can be obtained with the configuration of the ultraviolet light irradiation system 302 including the light source control unit 17 .

(Embodiment 4)
FIG. 13 is a flowchart for explaining an ultraviolet light irradiation method for setting the switching timing of the optical switch 12-2 of the ultraviolet light irradiation system (301 to 303). This method is an ultraviolet light irradiation system in which ultraviolet light generated by one ultraviolet light source unit 11 is time-divided by an optical switch 12-2, and the time-divided ultraviolet light is irradiated to a plurality of irradiation target areas AR, The switching timing of the optical switch 12-2 that time-divides the ultraviolet light is determined by the transmission loss of the ultraviolet light for each route 14, the irradiation area of the irradiation target area AR irradiated with the ultraviolet light, and the irradiation target area AR. is set based on at least one of the required inactivation times.

Specifically, it is designed as follows.
Step S01: Ultraviolet light output power P [W] of ultraviolet light source unit 11, loss L _fiber-n of each path 14 [a. u. ] and loss L _air-n [a. u. ], area S _n [m ² ] of each irradiation target area AR, and information on illuminance [W/m ² ], unit energy [J], or required deactivation time required by each irradiation target area AR. Further, in the case of the ultraviolet light irradiation system 302, the necessary power of ultraviolet light is calculated for each route.
Step S02: Judge whether the effect to be ensured by the ultraviolet light irradiation system (301 to 303) is fairness.
Step S03: If the effect to be ensured by the ultraviolet light irradiation system (301 to 303) is fairness ("Yes" in step S02), the optical switch 12- 2 is set in the switching control unit 15-2.
Step S04: Judge whether the effect to be ensured by the ultraviolet light irradiation system (301 to 303) is safety.
Step S05: If the effect to be ensured by the ultraviolet light irradiation system (301 to 303) is safety ("Yes" in step S04), the switching control unit changes the switching timing of the optical switch 12-2 according to (b1) described above. Set to 15-2.
Step S06: Judge whether the effect to be ensured by the ultraviolet light irradiation system (301 to 303) is efficiency.
Step S07: If the effect to be ensured by the ultraviolet light irradiation system (301 to 303) is efficiency ("Yes" in step S06), the switching control unit changes the switching timing of the optical switch 12-2 according to (c1) described above. Set to 15-2.
Step S08: If the effects to be ensured by the ultraviolet light irradiation system (301-303) are none of fairness, safety and efficiency, the design is aborted.
In addition, in the case of the ultraviolet light irradiation system 302, the following operations are added in steps S03, S05, and S07. The ultraviolet light irradiation system 302 can change the ultraviolet light power output from the ultraviolet light source unit 11 in synchronization with the switching timing of the optical switch 12-2. Therefore, the ultraviolet light power output from the ultraviolet light source unit 11 is set in the light source control unit 17 in synchronization with the switching timing set in the switching control unit 15-2.

3: Housing 11: Ultraviolet light source section 12: Light distribution section (equally branched)
12-2: optical switches 13, 13-1, . . . , 13-N: irradiation section 14: direction (optical fiber)
15-2: Switching control unit 16: Optical transmission line 17: Light source control unit 26: Optical transmission line 52: Solid core 52a: Region 53: Hole 53a: Hole group 53c: Hole 60:

Cladding

300, 301, 302 , 303: ultraviolet light irradiation system AR1, AR2, . . . , ARN: irradiation target area (area to be irradiated with ultraviolet light)

Claims

an ultraviolet light source that generates ultraviolet light;
N irradiating units that irradiate N (N is a natural number of 2 or more) irradiation target areas with the ultraviolet light;
an optical switch that switches the ultraviolet light to a direction to each of the irradiation units;
Setting the switching timing of the optical switch based on at least one of the transmission loss of the ultraviolet light for each of the routes, the irradiation area where the irradiation unit irradiates the ultraviolet light, and the required time for deactivation of the irradiation target area. a switching control unit;
An ultraviolet light irradiation system.
2. The ultraviolet light according to claim 1, wherein the switching control unit sets the switching timing so that an integrated light amount of the ultraviolet light irradiated to each of the irradiation target areas is equal to or less than a predetermined reference value. Light irradiation system.
3. The ultraviolet light irradiation system according to claim 1, wherein the switching control unit sets the switching timing so as to satisfy the integrated light quantity of the ultraviolet light required by each of the irradiation target areas.
4. The ultraviolet light according to any one of claims 1 to 3, further comprising a light source control section for varying the power of the ultraviolet light with respect to the ultraviolet light source section so as to interlock with the switching operation of the optical switch. irradiation system.
The ultraviolet light source unit and the optical switch are separated,
5. The ultraviolet light irradiation system according to any one of claims 1 to 4, further comprising an optical transmission line connecting said ultraviolet light source unit and said optical switch.