Ultraviolet irradiation system and ultraviolet irradiation method

Abstract

The purpose of the present invention is to provide a P-MP ultraviolet light irradiation system and ultraviolet light irradiation method with which it is possible to obtain a prescribed sterilization or similar effect.　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) irradiation units 13 for irradiating prescribed locations (irradiation target regions ste) with the ultraviolet light; an optical switch 12 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 for controlling the switching operation of the optical switch 12 so that the respective paths 14 are imparted with an opportunity to be supplied with an equal cumulative light amount per unit time, on the basis of the ultraviolet light transmission loss of each of the paths 14 and the irradiation area irradiated with ultraviolet light by the irradiation units 13.

Description

Technical Field

[0001] The present disclosure relates to an ultraviolet irradiation system that performs sterilization and virus inactivation using ultraviolet light.

Background Art

[0002] For purposes such as preventing infectious diseases, the demand for systems that perform sterilization and virus inactivation using ultraviolet light is increasing. There are roughly three categories of products in such systems. In this specification, when "sterilization etc." is described, it means sterilization and virus inactivation. (1) Mobile sterilization robot The product of Non-Patent Document 1 is an autonomous mobile robot that irradiates ultraviolet light. While moving inside a room in a building such as a hospital ward, the robot can irradiate ultraviolet light to achieve automatic sterilization etc. over a wide range without the need for human intervention. (2) Stationary air purifier The product of Non-Patent Document 2 is a device that is installed at a predetermined location on the ceiling or indoors and sterilizes etc. while circulating the indoor air. Since the device does not directly irradiate ultraviolet light and has no impact on the human body, highly safe sterilization is possible. (3) Portable sterilization device The product of Non-Patent Document 3 is a portable device equipped with an ultraviolet light source. The user can take the device to a desired area and irradiate ultraviolet light. Therefore, the device can be used in various places.

Prior Art Documents

Non-Patent Documents

[0003]

Non-Patent Document 1

Non-Patent Document 2

Non-Patent Document 3

Summary of the Invention

Problems to be Solved by the Invention

[0004] However, the devices described in the non-patent documents have the following problems. (A) Economy The product of Non-Patent Document 1 irradiates high-power ultraviolet light, so the device is large-scale and expensive. For this reason, the product of Non-Patent Document 1 has a problem that it is difficult to realize an economical system. (B) Versatility The product of Non-Patent Document 1 is limited to the places where the robot can move / enter for the ultraviolet light irradiation location, so it is difficult to irradiate ultraviolet light to fine places or deep places. The product of Non-Patent Document 2 sterilizes the circulated indoor air, so it is impossible to directly irradiate ultraviolet light to the place where sterilization etc. is desired. The product of Non-Patent Document 3 cannot irradiate ultraviolet light to, for example, thin pipelines or areas where people cannot enter. Thus, the products of the non-patent documents have problems with the versatility of being able to irradiate ultraviolet light to any place. (C) Operability The product of Non-Patent Document 3 is portable and can irradiate ultraviolet light in various places. However, in order to obtain sufficient sterilization and other effects at the target location, skills and knowledge are required of the user, and there are problems with operability.

[0005] In response to these problems, an ultraviolet light irradiation system using an optical fiber as shown in FIG. 11 can be considered. This ultraviolet light irradiation system transmits ultraviolet rays from a light source using a thin and easily bendable optical fiber, and irradiates the ultraviolet rays output from the tip of the optical fiber to the place where sterilization or the like is desired pinpoint. Since ultraviolet light can be irradiated to any place simply by moving the tip of the optical fiber, the versatility of the above problem (B) can be solved. In addition, since the movement and setting of the ultraviolet light source are not required and no skills or knowledge are required of the user, the operability of the above problem (C) can also be solved. Furthermore, by adopting a P-MP (Point to MultiPoint) system configuration such as that used in FTTH (Fiber To The Home), multiple locations can be sterilized or the like by sharing a single light source, so the economy of the above problem (A) can also be solved.

[0006] However, there are the following problems in realizing the P-MP configuration as an ultraviolet light irradiation system. (1) Increase in excess loss In the case of a P-MP configuration using a beam splitter as shown in FIG. 11, as the number of branches increases, a multi-stage configuration is formed, and the excess loss generated at each branch accumulates, making it difficult to obtain sufficient ultraviolet power from the tip of the optical fiber. (2) Switching control The P-MP configuration that solves the problem of the above excess loss is a P-MP configuration using an optical switch. If the optical switch is configured to switch the path of ultraviolet rays input from one port and make it communicate with any of a plurality of output ports by a mechanical mechanism (moving an optical fiber, a mirror, a prism, etc.) or a mechanism using MEMS, it will not be a multi-stage branching configuration. Therefore, the passing loss of the optical switch is less affected by the number of branches, and the problem of excess loss can be solved. On the other hand, in the configuration of the optical switch, since ultraviolet rays are intermittently transmitted to each output port by the path switching operation, it is difficult to sterilize or the like a plurality of locations simultaneously and constantly. Therefore, the ultraviolet light irradiation system with a P-MP configuration using an optical switch requires switching control considering a certain sterilization effect or the like for a plurality of target locations. However, the switching control method has not been clearly disclosed.

[0007] In order to solve these problems, an object of the present invention is to provide an ultraviolet light irradiation system and an ultraviolet light irradiation method having a P-MP configuration capable of obtaining a predetermined sterilization effect or the like.

Means for Solving the Problems

[0008] In order to achieve the above object, in the ultraviolet light irradiation system according to the present invention, an optical switch is arranged between an ultraviolet light source unit and an irradiation unit, and the optical path of the ultraviolet light is switched at a predetermined timing.

[0009] Specifically, the ultraviolet light irradiation system according to the present invention an ultraviolet light source unit that generates ultraviolet light, N (N is a natural number) irradiation units that irradiate the ultraviolet light to a desired location, an optical switch that switches the optical path of the ultraviolet light to the respective irradiation units, a switching control unit that controls the switching operation of the optical switch so as to give an opportunity for supplying an integrated light amount per unit time that is equal for each optical path based on the transmission loss of the ultraviolet light for each optical path and the irradiation area where the irradiation unit irradiates the ultraviolet light, is provided.

[0010] Further, the ultraviolet light irradiation method according to the present invention is an ultraviolet light irradiation method for irradiating ultraviolet light generated by an ultraviolet light source unit from N (N is a natural number) irradiation units to a desired location, when switching the optical path of the ultraviolet light to the respective irradiation units with an optical switch, characterized by giving an opportunity for supplying an integrated light amount per unit time that is equal for each optical path based on the transmission loss of the ultraviolet light for each optical path and the irradiation area where the irradiation unit irradiates the ultraviolet light.

[0011] This ultraviolet light irradiation system has a system configuration in which an ultraviolet light source and an irradiation unit are connected via an optical switch, and the optical switch switches the optical path of the ultraviolet light at a predetermined timing. The above timing is determined from the output power of the ultraviolet light source, the number of output ports of the optical switch, the optical fiber transmission loss to each target location, the ultraviolet light intensity obtained at each target location, and the required ultraviolet light energy. With this configuration, even if the optical switch intermittently transmits ultraviolet light to each target location, it is possible to ensure that the time during which sterilization or the like is not performed at a plurality of target locations is suppressed to a certain level or less, and the infection risk can be reduced.

[0012] Therefore, the present invention can provide an ultraviolet light irradiation system and an ultraviolet light irradiation method having a P-MP configuration that can obtain a predetermined effect such as sterilization.

[0013] The ultraviolet light irradiation system according to the present invention further includes a sensor that detects the presence of an avoidance object that should avoid the ultraviolet light at the desired location. When the sensor detects the presence of the avoidance object at the desired location corresponding to the one optical path during the opportunity of the one optical path, the switching control unit is characterized in that the ultraviolet light is not supplied to the one optical path during the opportunity.

[0014] This ultraviolet light irradiation system has a sensing function for detecting whether there is a person near each target location, and for the location where a person is detected, control is performed to stop the ultraviolet light irradiation or shift the irradiation timing.

[0015] For example, the switching control unit may separately give the opportunity to the one optical path after the avoidance object has disappeared, give the opportunity for the one optical path to another optical path, or supply the ultraviolet light only during the opportunity after the avoidance object has disappeared.

[0016] Note that the above inventions can be combined as much as possible.

Effects of the Invention

[0017] The present invention can provide an ultraviolet light irradiation system and an ultraviolet light irradiation method having a P-MP configuration capable of obtaining effects such as predetermined sterilization.

Brief Description of the Drawings

[0018]

Figure 1

Figure 2

Figure 3

Figure 4

Figure 5

Figure 6

Figure 7

Figure 8

Figure 9

Figure 10

Figure 11

Embodiments for Carrying Out the Invention

[0019] Embodiments of the present invention will be described with reference to the accompanying drawings. The embodiments described below are examples of the present invention, and the present invention is not limited to the following embodiments. In the present specification and drawings, components having the same reference numerals indicate the same components as each other.

[0020] (Embodiment 1) FIG. 1 is a diagram for explaining the ultraviolet light irradiation system 301 of the present embodiment. This embodiment is a case where the transmission loss of ultraviolet light to the irradiation target area ste is equal to the irradiation area. The ultraviolet light irradiation system 301 includes an ultraviolet light source unit 11 that generates ultraviolet light, N (N is a natural number) irradiation units 13 that irradiate the ultraviolet light to a desired location (irradiation target area ste), an optical switch 12 that switches the ultraviolet light to the respective paths 14 to the irradiation units 13, a switching control unit 15 that controls the switching operation of the optical switch 12 so as to give an opportunity for supplying an integrated light amount per unit time that is equal for each path 14 based on the transmission loss of the ultraviolet light for each path 14 and the irradiation area where the irradiation unit 13 irradiates the ultraviolet light, and is provided with.

[0021] The ultraviolet light source unit 11 outputs light (ultraviolet light) in the ultraviolet region that is effective for sterilization and the like. Let the power of the ultraviolet light output by the ultraviolet light source unit 11 be P [W]. The ultraviolet light source unit 11 and the optical switch 12 are connected by an optical fiber or a spatial path 16. The switching control unit 15 controls the switching operation of the optical switch 12.

[0022] The optical switch 12 outputs the ultraviolet light from the ultraviolet light source unit 11 to any one of the paths 14 according to an instruction from the switching control unit 15. Here, let the time required for path switching by the optical switch 12 be T sw [s]. The ultraviolet light output from the output ports 1 to N is irradiated to the irradiation target areas 1 to N through the paths 14 and the irradiation units 13, respectively.

[0023] The path 14 propagates the ultraviolet light intermittently distributed by the optical switch 12 to the respective irradiation units 13. The path 14 is an optical fiber. Since it is an optical fiber, it can be laid in fine places where conventional robots and devices cannot enter. FIG. 2 is a diagram for explaining the cross section of the optical fiber that can be used for the path 14. (1) Solid core optical fiber This optical fiber has a solid core 52 with a refractive index higher than that of the cladding 60 inside the cladding 60. "Solid" means "not hollow". Incidentally, the solid core can also be realized by forming an annular low refractive index region in the cladding. (2) Hole-assisted optical fiber This optical fiber has a solid core 52 and a plurality of holes 53 arranged on its outer periphery inside the cladding 60. The medium of the holes 53 is air, and the refractive index of air is sufficiently small compared to silica glass. Therefore, the hole-assisted optical fiber has the function of returning the light leaked from the core 52 back to the core 52 due to bending or the like, and is characterized by low bending loss. (3) Hole-structured optical fiber This optical fiber has a hole group 53a of a plurality of holes 53 inside the cladding 60, and has a refractive index lower than that of the host material (such as glass) more effectively. This structure is called a photonic crystal fiber. In this structure, a structure without a high refractive index core with a changed refractive index can be adopted, and the region 52a surrounded by the holes 53 can be used as an effective core region to confine light. Compared with an optical fiber having a solid core, the photonic crystal fiber can reduce the influence of absorption and scattering loss due to core additives, and can realize optical characteristics that cannot be realized in a solid-type optical fiber, such as reduction of bending loss and control of non-linear effects. (4) Hollow-core optical fiber In this optical fiber, the core region is formed of air. Light can be confined in the core region by adopting a photonic bandgap structure formed by a plurality of holes or an anti-resonant structure formed by glass fine wires in the cladding region. This optical fiber has a small non-linear effect and can supply high-power or high-energy lasers. (5) Coupled-core type optical fiber In this optical fiber, a plurality of solid cores 52 with a high refractive index are arranged adjacent to each other within a cladding 60. This optical fiber guides light through optical wave coupling between the solid cores 52. Since the coupled-core type optical fiber can disperse and transmit light by the number of cores, it can be made more powerful and can perform efficient sterilization accordingly. In addition, the coupled-core type optical fiber has the advantage of mitigating fiber degradation caused by ultraviolet rays and extending its lifespan.

[0024] The irradiation unit 13 irradiates the ultraviolet light transmitted through the branch path 14 onto a predetermined target location (irradiation target area ste) for performing sterilization or the like. The irradiation unit 13 is composed of an optical system such as a lens designed for the wavelength of the ultraviolet light. Here, let the loss from the ultraviolet light source unit 11 to the irradiation unit 13 (including the passing loss of the optical switch 12) be L fiber [a.u.], and let the loss from the irradiation unit 13 to the irradiation target area ste be L air [a.u.]. Also, let the area of the spot of the ultraviolet light irradiated onto the irradiation target area ste be S [m 2 .

[0025] FIG. 3 is a diagram for explaining the switching control of the optical switch 12 performed by the switching control unit 15. This control is an operation when the transmission loss and the irradiation area of the ultraviolet light to the irradiation target area ste are equal. The switching control unit 15 controls the optical switch 12 to repeat an operation of giving each branch path 14 (output ports 1 to N of the optical switch) an opportunity to supply ultraviolet light for a time T. The time T is the time obtained by Equation (1).

Equation

[0026] By operating the optical switch 12 in this way and supplying ultraviolet light during the said opportunity, it is possible to irradiate all the irradiation target areas ste with the amount of ultraviolet rays E [W·s / m 2 required for sterilization or the like in the shortest cycle. That is, the ultraviolet light irradiation system 301 applies the time T of Equation (2) to each irradiation target area ste inact[s]The effect such as sterilization can be ensured periodically. [Number]

[0027] Furthermore, even if the switching control unit 15 controls the optical switch 12 so that the time for supplying ultraviolet light to each output port becomes T / M [s] (M is a natural number of 2 or more), the same effect can be obtained.

[0028] (Embodiment 2) FIG. 3 is a diagram for explaining the ultraviolet light irradiation system 302 of the present embodiment. This embodiment is a case where the transmission loss of ultraviolet light to the irradiation target area ste and the irradiation area are different. The ultraviolet light irradiation system 302 has the same structure as the ultraviolet light irradiation system 301 in FIG. 1, but the path length is different for each path 14 and the irradiation area S for each irradiation target area ste is different. In this embodiment, only the parts different from the ultraviolet light irradiation system 301 will be described.

[0029] Let the power of the ultraviolet light output from the ultraviolet light source unit 11 be P [W]. Let the time required for path switching by the optical switch 12 be T sw [s]. Let the loss from the ultraviolet light source unit 11 to the irradiation unit 13 (including the passing loss of the optical switch 12) be L fiber-1 [a.u.] for each path 14, and L fiber-2 [a.u.], ···, L fiber-N [a.u.]. Let the loss from the irradiation unit 13 to each irradiation target area ste be L air-1 [a.u.], L air-2 [a.u.], ···, L air-N [a.u.]. Also, let the area of the spot of the ultraviolet light irradiated on each irradiation target area ste be S 1 [m 2 , S 2 [m 2 , ···, S N [m 2 .

[0030] FIG. 5 is a diagram for explaining the switching control of the optical switch 12 performed by the switching control unit 15. This control is an operation when the transmission loss of ultraviolet light to the irradiation target area ste and the irradiation area are different. The switching control unit 15 controls the optical switch 12 to repeat an operation of giving an opportunity to supply ultraviolet light to each output port i (i = 1, 2, ···, N) for a time T i respectively. T i is the time obtained by the formula (3).

Equation

[0031] By operating the optical switch 12 in this way and supplying ultraviolet light during the opportunity, the amount of ultraviolet rays E [W·s / m 2 required for sterilization or the like can be irradiated to all irradiation target areas ste in the shortest cycle. That is, the ultraviolet light irradiation system 302 can ensure the effect of sterilization or the like for each irradiation target area ste every T inact [s].

Equation

[0032] In addition, even if the switching control unit 15 controls the optical switch 12 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), the same effect can be obtained.

[0033] (Embodiment 3) FIG. 6 is a diagram for explaining the ultraviolet light irradiation system 303 of the present embodiment. This embodiment is a case where a function of detecting the presence or absence of an avoidance object (person or animal) to which ultraviolet light should be avoided in each irradiation target area ste is further provided. That is, the ultraviolet light irradiation system 303 further includes a sensor 21 that detects the presence of an avoidance object to which the ultraviolet light should be avoided in the desired location (irradiation target area ste) with respect to the ultraviolet light irradiation system 301 of FIG. 1 or the ultraviolet light irradiation system 302 of FIG. 2. When the sensor 21 detects the presence of the avoidance object in the desired location (irradiation target area ste) corresponding to the path 14 of 1 at the opportunity of the path 14 of 1, the switching control unit 15 is characterized in that the ultraviolet light is not supplied to the path 14 at that opportunity. In this embodiment, only the parts different from the ultraviolet light irradiation systems (301, 302) will be described.

[0034] Each sensor 21-i acquires various information D i (i = 1, 2, ···, N) of each irradiation target area ste and detects the presence or absence of an avoidance object. As combinations of "sensor" and "various information", for example, the following can be considered. If the sensor 21 is a camera, the various information D i is video information. If the sensor 21 is an infrared sensor, the various information D i is temperature information. If the sensor 21 is a microphone, the various information D i is audio information.

[0035] Each sensor 21-i transmits the information D i to the switching control unit 15 via the path 24. The path 24 can apply a wired communication method (for example, wired LAN, etc.) or a wireless communication method (for example, wireless LAN, etc.).

[0036] The switching control unit 15 performs switching control of the optical switch 12 based on the information D i . (Example 1) FIG. 7 is a diagram for explaining the switching control of the optical switch 12 performed by the switching control unit 15. The switching control unit 15 adds the following control to the switching control described in FIGS. 3 and 5. The additional control is to stop the supply of ultraviolet light to the output port to the irradiation target area ste when an avoidance object is detected in the irradiation target area ste, and to supply ultraviolet light to the output port to the irradiation target area ste when no avoidance object is detected in the irradiation target area ste at the next opportunity.

[0037] FIG. 8 is a flowchart for explaining the control. Specifically explaining with the examples of FIGS. 6 and 7, Step P1: Sensor 21-2 detects that there is a person in the vicinity of the irradiation target area ste2 for a certain period Ta. Step P2: The switching control unit 15 uses the information D from the sensor 21-2 2 to stop the supply of ultraviolet light to output port 2 during the opportunity included in period Ta (stop the ultraviolet light to the irradiation target area ste2). Step P3: If the sensor 21-2 does not detect a person in the next opportunity, the switching control unit 15 supplies ultraviolet light to output port 2 during that opportunity. Step P4: Determine the presence or absence of a person for the next irradiation target area ste-i (ste4), and Step P5: After checking up to the last irradiation target area ste-N, determine the presence or absence of a person from the irradiation target area ste-1 as the next opportunity. It becomes like this.

[0038] Although ultraviolet light is harmful to the human body depending on the wavelength, the ultraviolet light irradiation system 303 can perform the control described in Control Modes 1 and 2 while avoiding ultraviolet light irradiation to people by this control.

[0039] (Example 2) FIG. 9 is a diagram for explaining the switching control of the optical switch 12 performed by the switching control unit 15. The switching control unit 15 adds the following control to the switching control described in FIGS. 3 and 5. The additional control is to stop the supply of ultraviolet light to the output port for the irradiation target area ste when an avoidance object is detected in the irradiation target area ste, to supply ultraviolet light by advancing the opportunities of other output ports while an avoidance object is detected in the irradiation target area ste, and to give an opportunity to the output port to supply ultraviolet light after the avoidance object in the irradiation target area ste cannot be detected.

[0040] Specifically explaining with the examples of FIGS. 6 and 9, Step A1: Sensor 21-2 detects that there is a person in the vicinity of the irradiation target area ste2 for a certain period Ta. Step A2: Based on the information D from the sensor 21-2, the switching control unit 15 stops the supply of ultraviolet light to the output port 2 (stops the ultraviolet light to the irradiation target area ste2) during the opportunity included in the period Ta. 2 Step A3: The switching control unit 15 checks the presence or absence of people in other irradiation target areas ste during a certain period Ta. If there is no one in other irradiation target areas ste, it sequentially advances the opportunities of other output ports (output ports 3 and 4 in the figure) and supplies ultraviolet light to the output ports 3 and 4. Step A4: After the sensor 21-2 stops detecting a person, the switching control unit 15 gives an opportunity to the output port 2 and supplies ultraviolet light to the output port 2.

[0041] Also by this control, the ultraviolet irradiation system 303 can perform the control described in Control Modes 1 and 2 while avoiding ultraviolet irradiation to people, similar to the control example in FIG. 7. In addition, in the control example of FIG. 7, when a person is detected in the irradiation target area ste, it is necessary to wait for the supply of ultraviolet light to the corresponding location until the next opportunity, and the time during which the effect such as sterilization cannot be obtained becomes long. However, in this control, as soon as there is no one in the irradiation target area ste, the supply of ultraviolet light is carried out. Therefore, compared with the control of FIG. 7, the time during which the effect such as sterilization cannot be obtained can be shortened. As a result, the control example of FIG. 9 can reduce the infection risk.

[0042] (Example 3) FIG. 10 is a diagram for explaining the switching control of the optical switch 12 performed by the switching control unit 15. The switching control unit 15 adds the following control to the switching control described in FIGS. 3 and 5. When the switching control unit 15 detects an avoidance object in the irradiation target area ste or detects that a person has touched an object existing in the irradiation target area ste, it determines that sterilization, etc. is necessary, and supplies ultraviolet light to the output port of the corresponding irradiation target area ste at the next opportunity when the avoidance object is no longer detected in the irradiation target area ste, and in other cases, does not supply ultraviolet light to the output port at each opportunity.

[0043] ​This will be specifically described with reference to the examples of FIGS. 6 and 10. Step B1: Sensor 21-2 detects that there is a person in the irradiation target area ste2 or that a person has touched an object existing in the irradiation target area ste2. Note that the fixed period Tb1 is the interval between opportunities given to the irradiation target area ste2. Step B2: Based on the information D from sensor 21-2, if the switching control unit 15 does not detect a person at the next opportunity after the period Tb1, it supplies ultraviolet light to output port 2 at the next opportunity. 2 Step B3: Based on the information D from sensor 21-2, if the switching control unit 15 does not detect that there is a person in the irradiation target area ste2 or that a person has touched an object existing in the irradiation target area ste2 from the previous opportunity to the current opportunity, it does not supply ultraviolet light to output port 2 at the current opportunity. Step B4: Sensor 21-4 detects that there is a person in the irradiation target area ste4 or that a person has touched an object existing in the irradiation target area ste4. Note that the fixed period Tb2 is a period that spans one or multiple opportunities given to the irradiation target area ste4. 2 Step B5: Based on the information D from sensor 21-4, the switching control unit 15 stops supplying ultraviolet light to output port 4 during the opportunities included in the period Tb2 (stops ultraviolet light to the irradiation target area ste4). Step B6: Based on the information D from sensor 21-4, if the switching control unit 15 does not detect a person at the next opportunity after the period Tb2, it supplies ultraviolet light to output port 4 at the next opportunity. Step B7: Based on the information D from sensor 21-4, if the switching control unit 15 does not detect that there is a person in the irradiation target area ste4 or that a person has touched an object existing in the irradiation target area ste4 from the previous opportunity to the current opportunity, it does not supply ultraviolet light to output port 4 at the current opportunity. 4 Step B8: Sensor 21-6 detects that there is a person in the irradiation target area ste6 or that a person has touched an object existing in the irradiation target area ste6. Note that the fixed period Tb3 is a period that spans one or multiple opportunities given to the irradiation target area ste6. Step B9: Based on the information D from sensor 21-6, the switching control unit 15 stops supplying ultraviolet light to output port 6 during the opportunities included in the period Tb3 (stops ultraviolet light to the irradiation target area ste6). 4 Step B10: Based on the information D from sensor 21-6, if the switching control unit 15 does not detect a person at the next opportunity after the period Tb3, it supplies ultraviolet light to output port 6 at the next opportunity.

[0044] The ultraviolet light irradiation system 303 can also perform the control described in Control Modes 1 and 2 while avoiding ultraviolet irradiation of people, in the same manner as the control example of FIG. 7, by this control. In addition to the operations of Control Modes 1 and 2, this control can avoid ultraviolet irradiation of people and unnecessary ultraviolet light irradiation to locations where disinfection, etc. is not required.

[0045] (Advantages of the Invention) The present invention is characterized in that an ultraviolet light source and an irradiation unit installed near a target location such as sterilization are connected via an optical switch, and the path in the optical switch is switched at a predetermined timing. Due to this feature, it is possible to prevent a decrease in ultraviolet light power due to a multi-stage configuration with respect to the irradiation target area, and it is possible to ensure a certain sterilization effect and reduce the infection risk.

Explanation of symbols

[0046] 11: Ultraviolet light source unit 12: Optical switch 13, 13-1, ···, 13-N: Irradiation unit 14: Optical fiber 15: Switching control unit 16: Path 52: Solid core 52a: Region 53: Hole 53a: Hole group 53c: Hole 60: Cladding 301~303: Ultraviolet light irradiation system ste1, ste2, ···, steN: Irradiation target area (area to be irradiated with ultraviolet light)

Claims

1. An ultraviolet light source unit that generates ultraviolet light, N (N is a natural number) irradiation units that irradiate the ultraviolet light to a desired location, An optical switch that switches the ultraviolet light to the respective paths to the irradiation units, Based on the transmission loss of the ultraviolet light for each path and the irradiation area where each irradiation unit irradiates the ultraviolet light, a switching control unit that controls the switching operation of the optical switch so as to give an opportunity for an equal integrated light amount to be supplied to each path by switching to another path after each irradiation unit irradiates the ultraviolet light to the corresponding desired location for the time for each path calculated, An ultraviolet light irradiation system comprising:

2. The time for each path is calculated by the following formula, The ultraviolet light irradiation system according to Claim 1. 【Number C1】 T i: Time for each path E: Ultraviolet light amount P: Power of ultraviolet light L fiber - i: Loss from the ultraviolet light source unit to the irradiation unit for each path L air - i: Loss from the irradiation unit to the desired location for each path

3. Further comprising a sensor that detects the presence of an avoidance object that should avoid the ultraviolet light at the desired location, When, during the opportunity for one of the paths, the sensor detects the presence of the avoidance object at the desired location corresponding to the one path, The ultraviolet light irradiation system according to Claim 1 or 2, wherein the switching control unit does not supply the ultraviolet light to the one path during the opportunity.

4. The ultraviolet light irradiation system according to Claim 3, wherein the switching control unit separately gives the opportunity to the one path after the avoidance object has disappeared.

5. The ultraviolet light irradiation system according to Claim 3, wherein the switching control unit gives the opportunity for the one path to the other paths.

6. The ultraviolet light irradiation system according to Claim 3, wherein the switching control unit supplies the ultraviolet light only during the opportunity after the avoidance object has disappeared.

7. An ultraviolet light irradiation method for irradiating ultraviolet light generated by an ultraviolet light source unit from N (N is a natural number) irradiation units to a desired location, A switching control unit that switches the optical switch between the irradiation units switches the ultraviolet light to the respective paths to the irradiation units using the optical switch. When switching, each irradiation unit irradiates the desired location corresponding to it with the ultraviolet light for the time of each path calculated based on the transmission loss of the ultraviolet light for each path and the irradiation area of each irradiation unit for irradiating the ultraviolet light, and then switches to another path, thereby providing an opportunity for supplying an equal integrated light amount for each path. An ultraviolet light irradiation method characterized by this.

8. The time for each path is calculated by the following formula: The ultraviolet light irradiation method according to claim 7. 【Number C2】 Ti: Time for each path E: Ultraviolet light amount P: Power of ultraviolet light Lfiber-i: Loss from the ultraviolet light source unit to the irradiation unit for each path Lair-i: Loss from the irradiation unit to the desired location for each path

Images