WO2023084666A1

WO2023084666A1 - Ultraviolet light irradiation system

Info

Publication number: WO2023084666A1
Application number: PCT/JP2021/041472
Authority: WO
Inventors: 聖成川; 友宏谷口; 誉人桐原; 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: 2021-11-11
Filing date: 2021-11-11
Publication date: 2023-05-19

Abstract

The purpose of the present invention is to provide an ultraviolet light irradiation system capable of flexibly responding to each of requests from irradiation target regions.　This ultraviolet light irradiation system 301 comprises: an ultraviolet light source unit 11 which generates ultraviolet light; N (N is a natural number no less than 2) irradiation units 13 which irradiate M (M is a natural number no less than 2) irradiation target regions with the ultraviolet light; a light distribution unit 12-10 which distributes the ultraviolet light to paths 14 toward the respective irradiation units 13; and a direction control unit 18 which controls the direction of the ultraviolet light output from the irradiation units 13 so that the ultraviolet light output from at least two irradiation units 13 among the N irradiation units is superposed and emitted onto one irradiation target region 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 this device 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 a place to be sterilized with ultraviolet light.
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 irradiation target areas differ in transmission loss, area, and required time for deactivation in the optical fiber. 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

The issue is explained in Figure 1. The irradiation target area ARN has a standard amount of bacteria and viruses, while the irradiation target area AR1 has a large amount of bacteria and viruses and is a place that needs to be sterilized in a short time, and the irradiation target area AR2 has bacteria and viruses. It should be a place where the amount of waste is small and sterilization, etc. is unnecessary. Even in this case, the ultraviolet light irradiation system 300 equally distributes the ultraviolet light to all the optical fibers 14 (if the light distribution unit is an equal branch coupler, the ultraviolet light power is equally branched; Since the time slots are equally assigned to each output port, the ultraviolet light is supplied to the irradiation target area AR2, which does not require sterilization, etc., while the same amount of ultraviolet light is distributed to the irradiation target area AR1, so sterilization, etc. is shortened. It is inefficient because it cannot be completed in time. In other words, the ultraviolet light irradiation system 300 has a problem that it is difficult to flexibly meet the requirements of each irradiation target area.

An object of the present invention is to provide an ultraviolet light irradiation system that can flexibly meet the requirements of each irradiation target area in order to solve the above problems.

In order to achieve the above object, the ultraviolet light irradiation system according to the present invention includes an irradiation unit whose irradiation direction is variable, and emits ultraviolet light from other irradiation units to an irradiation target area that requires sterilization or the like in a short time. It was decided to irradiate by superimposing the light to increase the illuminance.

Specifically, the ultraviolet light irradiation system according to the present invention includes:
an ultraviolet light source that generates ultraviolet light;
N (N is a natural number of 2 or more) irradiation units that irradiate M (M is a natural number of 2 or more) irradiation target regions with the ultraviolet light;
a light distribution unit that distributes the ultraviolet light to each of the irradiation units;
A direction for instructing the irradiating unit on the direction of the ultraviolet light to be output so that the ultraviolet light output from at least two of the N irradiating units is superimposed and irradiates one irradiation target area. a control unit;
Prepare.

Further, the ultraviolet light irradiation system according to the present invention judges the necessity of irradiating the irradiation target area with the ultraviolet light, and irradiates the ultraviolet light irradiating the irradiation target area with the low necessity. It is characterized by further comprising a total control unit that instructs the direction control unit to irradiate the irradiation target area with high efficiency.

This ultraviolet light irradiation system can change the direction in which the irradiation unit emits ultraviolet light. The irradiating unit, which is in charge of an irradiation target area that does not require sterilization or the like, changes the irradiation direction of the ultraviolet light to an irradiation target area that requires sterilization or the like in a short period of time. For this reason, in an irradiation target area where sterilization or the like is desired to be performed in a short time, the ultraviolet light from the irradiation section in charge of itself and the ultraviolet light from the irradiation section in charge of the others are superimposed, and the illuminance of the ultraviolet light increases. As a result, sterilization and the like of the irradiation target area can be completed in a short time.

Therefore, the present invention can provide an ultraviolet light irradiation system that can flexibly meet the requirements of each irradiation target area.

In addition, since the ultraviolet light is not applied to an irradiation target area that does not require sterilization or the like, and the ultraviolet light is transferred to a necessary irradiation target area, the efficiency of the entire ultraviolet light irradiation system is increased. Efficiency here means:
(a) It is not necessary to change the output of the ultraviolet light source because the irradiation target area to be sterilized or the like in a short time can be dealt with by switching the ultraviolet light. That is, the output of the ultraviolet light source is more efficient in terms of electric power than corresponding output.
(b) Ultraviolet light is directed to a desired irradiation target area where sterilization or the like is unnecessary, and the ultraviolet light is concentrated, so that the time required for sterilization or the like can be shortened. In other words, the total time for sterilization and the like can be shortened, and the efficiency in terms of time is increased.

The light distribution unit of the ultraviolet light irradiation system according to the present invention has a variable distribution ratio for distributing the ultraviolet light to each of the directions, and the general control unit distributes the ultraviolet light to one irradiation target area. may be instructed to the light distribution unit to increase the distribution ratio to the direction to the irradiation unit on which is superimposed. By adjusting the distribution ratio to each direction as well as the irradiation direction of the ultraviolet light, it is possible to more flexibly meet the requirements of each irradiation target area.

The ultraviolet light irradiation system according to the present invention further comprises a sensor unit for detecting whether or not there is an avoidance target to be avoided from being exposed to the ultraviolet light in a region including the irradiation target region,
The integrated control unit sets the irradiation target area where the avoidance target exists as the irradiation target area to be superimposed with the ultraviolet light, and performs irradiation from the plurality of irradiation units during a time when the avoidance target is not present in the irradiation target area. The irradiation target area may be irradiated with the ultraviolet light. It is possible to prevent ultraviolet light from being applied to avoidance targets existing in the irradiation target area, thereby enhancing safety.

The ultraviolet light irradiation system according to the present invention further includes a monitor unit that observes the amount of ultraviolet light for each of the directions,
The general control unit superimposes the ultraviolet light on the direction control unit when the amount of the ultraviolet light irradiated to the irradiation target area on which the ultraviolet light is superimposed exceeds a predetermined value. The irradiation of the irradiation target area may be terminated. Excessive ultraviolet light is prevented from being applied to the irradiation target area, and the efficiency of the entire ultraviolet light irradiation system is increased.

The irradiation unit of the ultraviolet light irradiation system according to the present invention has an optical delay circuit with a variable delay amount, and the direction control unit superimposes the ultraviolet light on one irradiation target area. The optical delay circuit is adjusted based on the distance of each path from the light distribution unit to the irradiation target area so that the phases of the ultraviolet light are aligned in the irradiation target area. Attenuation of power due to superimposition can be avoided.

The above inventions can be combined as much as possible.

The present invention can provide an ultraviolet light irradiation system that can flexibly meet the requirements of each irradiation target area.

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 ultraviolet light irradiation system which concerns on this invention. It is a figure explaining 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.

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), the power per unit area of the ultraviolet light irradiated to the irradiation target area AR is defined as illuminance (unit: W/m ² ), and the cumulative amount of light per unit area is defined as ultraviolet light amount (unit: J/m ² or W·s/m ² ).

(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 (N is a natural number of 2 or more) irradiation units 13 that irradiate M (M is a natural number of 2 or more) irradiation target areas AR with the ultraviolet light;
a light distribution unit 12-10 for distributing the ultraviolet light to a path 14 to each irradiation unit 13;
A direction for instructing the irradiation unit 13 of the direction of the ultraviolet light to be output so that the ultraviolet light output from at least two of the N irradiation units 13 is superimposed to irradiate one irradiation target area AR. a control unit 18;
Prepare.

The ultraviolet light source unit 11 outputs light in the ultraviolet region (ultraviolet light) that is effective for sterilization and the like. The ultraviolet light source section 11 and the light distribution section 12-10 are connected by an optical transmission line 16, which is an optical fiber or space.

The optical splitter 12-10 is an equal splitting coupler, an unequal splitting coupler, a variable splitting ratio coupler, or an optical switch.
The equal splitting coupler equally splits the power of the ultraviolet light input through the optical transmission line 16 to each output port.
The unequal splitting coupler splits the power of the ultraviolet light input through the optical transmission line 16 to each output port at a preset splitting ratio. The unequal branch coupler is, for example, the unequal branch coupler disclosed in JP-A-2020-036068.

The variable branching ratio coupler can change the branching ratio according to instructions from the general control unit 15-10. The branching ratio variable coupler branches the power of the ultraviolet light input through the optical transmission line 16 according to the branching ratio, and outputs the branched light to a plurality of output ports. The variable branching ratio coupler has a configuration including a Mach-Zehnder interferometer that changes the branching ratio with a heater, as disclosed in Reference 1, for example.
(Reference 1) NTT Technical Journal (https://www.ntt.co.jp/journal/0505/files/jn200505012.pdf), published in May 2005

The optical switch outputs the ultraviolet light input through the optical transmission line 16 to one of the output ports according to the switching timing specified by the general control unit 15-10. The time during which ultraviolet light is output to each output port is called a time slot.

In this specification, the "distribution ratio" means the time ratio in the case of an optical switch, and the branch ratio in the case of a coupler.

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 path 14 propagates the ultraviolet light distributed by the light distribution section 12-10 to each irradiation section 13. FIG. 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 cross sections of optical fibers that can be used for the optical

fiber transmission lines

16 and 14. As shown in FIG.
(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 to the core 52 again, 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 forming a photonic bandgap structure with a plurality of holes in the cladding region or an anti-resonant structure with glass wires. 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 irradiation unit 13 also includes an actuator that moves the optical system and changes the irradiation direction of the ultraviolet light.

The direction control unit 18 instructs the actuator of the irradiating unit 13 about the direction of the ultraviolet light to be irradiated (which irradiation target area AR to irradiate). The irradiation units 13 each have an irradiation target area AR for which they are in charge. For example, the irradiation unit 13-1 is in charge of the irradiation target area AR1, the irradiation unit 13-2 is in charge of the irradiation target area AR2, . . . the irradiation unit 13-N is in charge of the irradiation target area ARN. Normally, the direction control unit 18 instructs the actuators of the respective irradiation units 13 to irradiate ultraviolet light onto the irradiation target areas AR for which they are responsible.

The integrated control unit 15-10 determines the necessity of irradiating the irradiation target area AR with the ultraviolet light, and irradiates the irradiation target area AR with the low necessity with the ultraviolet light with the high necessity irradiation. The direction control unit 18 is instructed to irradiate the target area AR.

For example, assume that the virus load in the irradiation target area AR1 has increased and the virus load in the irradiation target area AR2 has decreased. In this case, it is desirable to quickly sterilize the irradiation target area AR1 by increasing the amount of ultraviolet light, while sterilizing the irradiation target area AR2 is unnecessary for the time being.

Therefore, the general control unit 15-10 obtains such information and instructs the direction control unit 18 to change the irradiation direction of the ultraviolet light from the irradiation unit 13-2 from the irradiation target area AR2 to the irradiation target area AR1. do. The direction control unit 18 instructs the actuator of the irradiation unit 13-2 to change the irradiation direction from the irradiation target area AR2 to the irradiation target area AR1. Then, the ultraviolet light from the irradiating section 13-1 and the ultraviolet light from the irradiating section 13-2 are superimposed on the irradiation target area AR1 to increase the amount of ultraviolet light, and sterilization and the like can be completed in a short time. In this way, the integrated control unit 15-10 appropriately instructs the irradiation units 13 about the irradiation direction of the ultraviolet light, so that sterilization or the like can be realized in a short time.

When the distribution ratio of the light distribution unit 12-10 is variable, the general control unit 15-10 controls the distribution ratio to the route 14 to the irradiation unit 13 that superimposes the ultraviolet light on one irradiation target area AR. may be instructed to the optical distributor 12-10 to increase the .

Specifically, a case in which the ultraviolet light from the irradiation unit 13-1 and the ultraviolet light from the irradiation unit 13-2 are superimposed on the irradiation target area AR1 will be described.
When the light distribution unit 12-10 is a variable branching ratio coupler, the general control unit 15-10 changes the irradiation direction of the ultraviolet light from the irradiation unit 13-2 from the irradiation target area AR2 to the irradiation target area AR1. In addition to instructing the control unit 18, it instructs the optical distribution unit 12-10 to increase the branching ratio of the

output ports

1 and 2. FIG.
Further, when the light distribution unit 12-10 is an optical switch, the general control unit 15-10 changes the irradiation direction of the ultraviolet light of the irradiation unit 13-2 from the irradiation target area AR2 to the irradiation target area AR1. In addition to instructing the control unit 18, the optical distribution unit 12-10 is instructed to increase the time slots of the

output ports

1 and 2. FIG.

When the general control unit 15-10 outputs an instruction to superimpose the ultraviolet light, by increasing the distribution ratio of the output port to the irradiation target area on which the ultraviolet light is superimposed on the light distribution unit 12-10, the time can be shortened. sterilization etc. can be realized.

(Embodiment 2)
FIG. 4 is a diagram illustrating the ultraviolet light irradiation system 302 of this embodiment. Compared to the ultraviolet light irradiation system 301 of FIG. 2, the ultraviolet light irradiation system 302 has a sensor unit that detects whether or not there is an avoidance target H that should be avoided from being exposed to the ultraviolet light in an area including the irradiation target area AR. 31 is further provided.

The sensor unit 31-n (where n is an integer from 1 to N) detects the existence and movement of each irradiation target area ARn and avoidance targets (humans, animals, etc.) H in the vicinity thereof. For example, the sensor unit 31 performs temperature acquisition by a thermometer, infrared acquisition by an infrared sensor, image acquisition by a camera, light acquisition by LiDAR (Light Detection and Ranging), etc., and information processing (shape, face, fingerprint, vein, iris etc.) to detect the existence and movement of the avoidance target.

The sensor unit 31-n monitors not only whether or not the object to be avoided H exists within the irradiation target area ARn, but also the periphery of the irradiation target area ARn. Therefore, based on the movement of the avoidance target H, the sensor unit 31-n determines whether the avoidance target H will enter the irradiation target area ARn or not, or whether the avoidance target H will move away from the irradiation target area ARn. It is possible to detect whether the
Then, the sensor section 31 notifies the integrated control section 15-10 of the detection result. The notification to the integrated control unit 15-10 may be wired or wireless.

The general control unit 15-10 receives the notification from the sensor unit 31, and designates the irradiation target area AR in which the avoidance target H exists as the target for superimposing the ultraviolet light. In the example of FIG. 4, since the sensor unit 31-1 notifies that the avoidance target H exists in the irradiation target area AR1, the integrated control unit 15-10 sterilizes the irradiation target area AR1 in a short time. Judged as a target. Then, since the sensor unit 31-2 notifies that the avoidance target H does not exist in the irradiation target area AR2, the total control unit 15-10 causes the irradiation unit 13-2 to irradiate the irradiation target area AR2 with ultraviolet light. A decision is made to turn to area AR1.

Here, the general control unit 15-10 irradiates the irradiation target area AR with the ultraviolet light from the plurality of irradiation units 13 during the time when the avoidance target H is not present in the irradiation target area AR. When the ultraviolet light is superimposed, the amount of ultraviolet light increases and there is a possibility that the object to be avoided H will be harmed. For this reason, the integrated control unit 15-10 superimposes the ultraviolet light during the time when the avoidance target H is not present, thereby enhancing safety. In the example of FIG. 4, the general control unit 15-10 redirects the ultraviolet light from the irradiation unit 13-2 to the irradiation target area AR1 after the avoidance target H has left the irradiation target area AR1.

(Embodiment 3)
FIG. 5 is a diagram illustrating the ultraviolet light irradiation system 303 of this embodiment. Compared to the ultraviolet light irradiation system 301 of FIG. 2, the ultraviolet light irradiation system 303 further includes a monitor unit 41 that observes the amount of ultraviolet light for each route 14 . The monitor unit 41 may be arranged on the route 14 to measure the amount of ultraviolet light input to the irradiation unit 13, measure the amount of ultraviolet light emitted by the irradiation unit 13, or measure the amount of ultraviolet light emitted by the irradiation unit 13. The amount of ultraviolet light received by the entire target area AR may be measured. Note that the amount of light is the integrated amount of light (unit: J), power (unit: W), illuminance in the irradiation target area AR (unit: W/m ² ), energy per unit area in the irradiation target area AR (unit: J/m ² or W·s/m ² ).
Then, the monitor section 41 notifies the total control section 15-10 of the amount of light. The notification to the integrated control unit 15-10 may be wired or wireless.

The general control unit 15-10 superimposes the ultraviolet light on the direction control unit 18 when the amount of the ultraviolet light irradiated to the irradiation target area AR on which the ultraviolet light is superimposed exceeds a predetermined value. to terminate the irradiation of the irradiation target area AR. The general control unit 15-10 receives the notification from the monitor unit 41, and terminates superimposed irradiation of ultraviolet light when the amount of ultraviolet light in the irradiation target area AR on which the ultraviolet light is superimposed exceeds a predetermined value. The predetermined value is determined by the amount of light required for deactivation of the irradiation target area AR. The amount of light required for inactivation is the amount of ultraviolet light (unit: J/m ² ) required to satisfy the desired inactivation (how much initial bacteria are reduced or how much viruses are inactivated). means.
In this way, by ending superimposed irradiation of ultraviolet light when the amount of ultraviolet light exceeds a predetermined value, excessive sterilization etc. can be avoided, and ultraviolet light is not irradiated like the irradiation target area AR2 (sterilization etc. is not done).

In the example of FIG. 5, the irradiation section 13-1 and the irradiation section 13-2 are currently irradiating the irradiation target area AR1 with superimposed ultraviolet light. The integrated control unit 15-10 sums the amounts of ultraviolet light notified by the monitor units 41 of the irradiation units 13-1 and 13-2 and compares the sum with a predetermined value. When the total amount of ultraviolet light exceeds a predetermined value, the total control unit 15-10 determines that the sterilization or the like is completed, and causes the direction control unit 18 to irradiate the ultraviolet light irradiation direction of the irradiation unit 13-2 from the irradiation target area AR1. It instructs to return to the target area AR2.

(Embodiment 4)
In the case where the light distribution unit 12-10 has the ultraviolet light source unit 11 as a laser and an equal branching coupler, an unequal branching coupler, or a variable branching ratio coupler, superimposing the ultraviolet light on one irradiation target area AR results in Light can be attenuated due to its wave nature.
Therefore, the irradiation unit 13 of the ultraviolet light irradiation system (301 to 303) has an optical delay circuit with a variable delay amount. Then, when superimposing the ultraviolet light on one irradiation target area AR, the direction control unit 18 determines the irradiation target area AR based on the distance of each route from the light distribution unit 12-10 to the irradiation target area AR. to adjust the optical delay circuit so that the phases of the ultraviolet light are aligned.
There are known examples of the optical delay circuit as follows.
(Public example 1) Optical modulator (https://www.japanlaser.co.jp/product/conoptics_modulation-systems/, retrieved on October 21, 2021)
(Public Known Example 2) Phase Modulator (https://www.daico.co.jp/products/products.php?id=84, retrieved on Oct. 21, 2021)
(Public Known Example 3) Optical Delay Line (https://www.optoscience.com/maker/oz/fiber_device/optical_delay_line.html, retrieved on October 21, 2021)

The example in Fig. 2 will be explained. The direction control unit 18 preliminarily determines the optical path length from the light distribution unit 12-10 to each irradiation unit 13, and the optical path length to each irradiation target area AR for each irradiation unit 13 (from the irradiation unit 13-1 to the irradiation target area AR1, AR2, . AR2, . . . , the optical path length to ARN). When the total control unit 15-10 instructs to change the ultraviolet light irradiation direction of the irradiation unit 13-2 to the irradiation target area AR1, the direction control unit 18 changes the ultraviolet light irradiation direction of the irradiation unit 13-2 to the irradiation target. The amount of change in the optical path length when the area AR2 is changed to the irradiation target area AR1 is calculated. The optical path length that does not weaken (the optical path length from the light distribution unit 12-10 to the irradiation target area AR1 via the irradiation unit 13-2) is calculated. Then, the direction control unit 18 adjusts the optical delay circuit of the irradiation unit 13-2 so that the calculated optical path length is achieved.

The ultraviolet light irradiation system of this embodiment can avoid weakening the illuminance due to interference when trying to superimpose the ultraviolet light in order to increase the illuminance.

11: Ultraviolet light source unit 12: Light distribution unit (equally branched)
12-10: Light distribution units 13, 13-1, . . . , 13-N: Irradiation unit 14: Direction (optical fiber)
15-10: General control unit 16: Optical transmission line 18: Direction control units 31, 31-1, . Hole group 53c: Hole 60:

Cladding

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

Claims

an ultraviolet light source that generates ultraviolet light;
N (N is a natural number of 2 or more) irradiation units that irradiate M (M is a natural number of 2 or more) irradiation target regions with the ultraviolet light;
a light distribution unit that distributes the ultraviolet light to each of the irradiation units;
A direction for instructing the irradiating unit on the direction of the ultraviolet light to be output so that the ultraviolet light output from at least two of the N irradiating units is superimposed and irradiates one irradiation target area. a control unit;
An ultraviolet light irradiation system.
Determining the necessity of irradiating the irradiation target area with the ultraviolet light, and irradiating the irradiation target area with the high necessity with the ultraviolet light irradiating the irradiation target area with the low necessity 2. The ultraviolet light irradiation system according to claim 1, further comprising a general control section for instructing said direction control section.
The light distribution unit has a variable distribution ratio for distributing the ultraviolet light to each of the directions,
The integrated control unit is characterized in that it instructs the light distribution unit to increase the distribution ratio to the direction to the irradiation unit that superimposes the ultraviolet light on one irradiation target area. The ultraviolet light irradiation system according to claim 2.
further comprising a sensor unit for detecting whether or not there is an avoidance target to be avoided from being exposed to the ultraviolet light in a region including the irradiation target region;
The integrated control unit sets the irradiation target area where the avoidance target exists as the irradiation target area to be superimposed with the ultraviolet light, and performs irradiation from the plurality of irradiation units during a time when the avoidance target is not present in the irradiation target area. 4. The ultraviolet light irradiation system according to claim 2, wherein the irradiation target area is irradiated with the ultraviolet light.
further comprising a monitor unit that observes the amount of ultraviolet light for each of the routes;
The general control unit superimposes the ultraviolet light on the direction control unit when the amount of the ultraviolet light irradiated to the irradiation target area on which the ultraviolet light is superimposed exceeds a predetermined value. 5. The ultraviolet light irradiation system according to any one of claims 1 to 4, wherein the irradiation of the irradiation target area is terminated.
The irradiation unit has an optical delay circuit with a variable delay amount,
When superimposing the ultraviolet light on one of the irradiation target areas, the direction control unit controls the phase of the ultraviolet light in the irradiation target area based on the distance of each route from the light distribution unit to the irradiation target area. 6. The ultraviolet light irradiation system according to any one of claims 1 to 5, wherein the optical delay circuit is adjusted so that