Ultraviolet light irradiation system

Abstract

The purpose of the present invention is to provide: an ultraviolet light irradiation system that can reduce unevenness in irradiation even in an object which has a complicated three-dimensional shape and that can decrease, on a surface of the object, a portion in which sterilization or virus inactivation is incomplete; and a method for controlling the ultraviolet light irradiation system.　An ultraviolet light irradiation system according to the present invention comprises: an ultraviolet light source unit 11 that generates ultraviolet light; a plurality of irradiation units 13 that are disposed around an irradiation target object TAR which is arbitrarily shaped and that irradiate the irradiation target object TAR with the ultraviolet light; a branching unit 12 that distributes the ultraviolet light from the ultraviolet light source unit 11 to each of the plurality of irradiation units 13; a measurement unit 21 that measures a state of the irradiation target object TAR; and a control unit 15 that adjusts the amount of the ultraviolet light distributed by the branching unit 12 so that the cumulative irradiation amount of the ultraviolet light is equalized more between positions on the surface of the irradiation target object TAR on the basis of the state of the irradiation target object TAR.

Description

UV Light Irradiation System

[0001] The present disclosure relates to an ultraviolet light irradiation system that irradiates an object at a distance with ultraviolet light via an optical transmission path such as an optical fiber.

[0002] For purposes such as preventing infectious diseases, there is an increasing demand for ultraviolet light irradiation systems that use ultraviolet light for sterilization or inactivation. One known method of sterilization or inactivation is an ultraviolet light irradiation system that uses an ultraviolet light source unit 11, an optical fiber 16, and an irradiation unit 13, as shown in Figure 1, and that directly irradiates a specific location with ultraviolet light without requiring a large-scale device (see, for example, Non-Patent Documents 1 and 2). By using this ultraviolet light irradiation system, it is possible to deliver ultraviolet light using an optical fiber to sterilize or inactivate even in places or situations where direct irradiation with ultraviolet light is difficult.

[0003] In ultraviolet light irradiation systems using optical fibers, there are also configurations in which a branching section 12 is arranged in the optical transmission path as shown in Figure 2 (ultraviolet light irradiation systems using branched optical fibers) in order to efficiently sterilize or inactivate multiple irradiation target areas AR.

[0004] NTT News Release (November 13, 2020), https: / / group.ntt / jp / newsrelease / 2020 / 11 / 13 / 201113b.html, retrieved August 21, 2023. Katsuhisa Taguchi et al., "Virus Infection Prevention Technology Using Ultraviolet Fiber Transmission," Institute of Electronics, Information and Communication Engineers, Communication Systems Study Group, October 27, 2022.

[0005] When the object to be irradiated with ultraviolet light is three-dimensional, the ultraviolet light travels in a straight line, so the ultraviolet irradiation system of Fig. 1 cannot irradiate the object from all directions. Even in this case, the ultraviolet light irradiation system of Fig. 2 can irradiate the object from multiple directions by arranging multiple irradiation units 13 around the object TAR, making it possible to irradiate the entire surface of the three-dimensional object TAR with ultraviolet light (see Fig. 3).

[0006] 4, when the object TAR has a complex three-dimensional shape, even if a plurality of irradiation units 13 are arranged around the object TAR, some surface areas will be strongly irradiated with ultraviolet light and some surface areas will be weakly irradiated. In other words, when irradiating an object with a complex three-dimensional shape with ultraviolet light, even if a plurality of irradiation units of an ultraviolet light irradiation system using a branched optical fiber are arranged around the object, uneven irradiation will occur with some areas being strongly irradiated with ultraviolet light and some areas being weakly irradiated, and there is a problem that it is difficult to achieve the desired sterilization or virus inactivation in the areas where the light intensity is weak.

[0007] Therefore, in order to solve the above-mentioned problems, the present invention aims to provide an ultraviolet light irradiation system and a control method thereof that can reduce uneven irradiation even on objects with complex three-dimensional shapes and reduce areas of incomplete sterilization or virus inactivation on the surface of the object.

[0008] In order to achieve the above object, the ultraviolet light irradiation system according to the present invention measures the state of an object and adjusts the amount of ultraviolet light irradiated from each irradiation unit based on the measurement result.

[0009] Specifically, the ultraviolet light irradiation system according to the present invention is characterized by comprising: an ultraviolet light source unit that generates ultraviolet light; a plurality of irradiation units that are arranged around an irradiation object of any shape and that irradiate the ultraviolet light onto the irradiation object; a branching unit that distributes the ultraviolet light from the ultraviolet light source unit to each of the irradiation units; a measurement unit that measures the state of the irradiation object; and a control unit that adjusts the distribution amount of the ultraviolet light in the branching units so that the cumulative irradiation amount of the ultraviolet light at each position on the surface of the irradiation object approaches uniformity based on the state of the irradiation object.

[0010] Furthermore, the control method according to the present invention is a control method for an ultraviolet light irradiation system in which ultraviolet light generated in an ultraviolet light source unit is distributed by a branching unit and irradiated onto an irradiation object of any shape from a plurality of irradiation units arranged around the irradiation object, and is characterized by measuring the state of the irradiation object, and adjusting the distribution amount of the ultraviolet light in the branching unit based on the state of the irradiation object so that the cumulative irradiation amount of the ultraviolet light at each position on the surface of the irradiation object approaches uniformity.

[0011] For example, the measurement unit is characterized in that it grasps the shape of the irradiation object or measures the distance to the surface of the irradiation object for each of the irradiation units. In this configuration, the measurement unit measures the shape of the irradiation object and adjusts the amount of ultraviolet light distributed from the branching unit to each irradiation unit according to the measured shape, thereby smoothing the amount of ultraviolet light irradiated onto the irradiation object.

[0012] For example, the measurement unit may measure the intensity of the ultraviolet light at each position on the surface of the irradiation object. In this configuration, the measurement unit measures the intensity of the ultraviolet light irradiated onto the irradiation object (the intensity at multiple positions on the surface of the irradiation object), and adjusts the amount of ultraviolet light distributed from the branching unit to each irradiation unit according to the measured intensity of the ultraviolet light, thereby smoothing the amount of ultraviolet light irradiated onto the irradiation object.

[0013] The control unit may adjust the distribution amount of the ultraviolet light by a branching ratio of the branching unit, or may adjust the distribution amount of the ultraviolet light at a timing when the branching unit switches to each path.

[0014] Therefore, the present invention can provide an ultraviolet light irradiation system and a control method thereof that can reduce uneven irradiation even on objects with complex three-dimensional shapes and reduce areas of incomplete sterilization or virus inactivation on the surface of the object.

[0015] The above inventions can be combined as much as possible.

[0016] The present invention can provide an ultraviolet light irradiation system and a control method thereof that can reduce uneven irradiation even on objects with complex three-dimensional shapes and reduce areas of incomplete sterilization or virus inactivation on the surface of the object.

[0017] FIG. 1 is a diagram for explaining an ultraviolet light irradiation system. FIG. 2 is a diagram for explaining an ultraviolet light irradiation system. FIG. 3 is a diagram for explaining an ultraviolet light irradiation system. FIG. 4 is a diagram for explaining a problem of an ultraviolet light irradiation system. FIG. 5 is a diagram for explaining an ultraviolet light irradiation system according to the present invention. FIG. 6 is a diagram for explaining an ultraviolet light irradiation system according to the present invention. FIG. 7 is a diagram for explaining an ultraviolet light irradiation system according to the present invention. FIG. 8 is a diagram for explaining a control method according to the present invention.

[0018] The following description of the preferred embodiments of the present invention will be given with reference to the accompanying drawings. The preferred embodiments described below are examples of the present invention, and the present invention is not limited to the preferred embodiments. In this specification and the drawings, components having the same reference numerals are intended to represent the same components.

[0019] 5 to 7 are diagrams illustrating an ultraviolet light irradiation system according to this embodiment. The ultraviolet light irradiation system includes an ultraviolet light source unit 11 that generates ultraviolet light, a plurality of irradiation units 13 that are arranged around an irradiation object TAR of any shape and that irradiate the irradiation object TAR with the ultraviolet light, a branching unit 12 that distributes the ultraviolet light from the ultraviolet light source unit 11 to each irradiation unit 13, a measurement unit 21 that measures the state of the irradiation object TAR, and a control unit 15 that adjusts the distribution amount of the ultraviolet light in the branching unit 12 based on the state of the irradiation object TAR so that the cumulative irradiation amount of the ultraviolet light at each position on the surface of the irradiation object TAR approaches uniformity.

[0020] This embodiment is characterized in that the measurement unit 21 grasps the shape of the irradiation object TAR or measures the distance to the surface of the irradiation object TAR for each irradiation unit 13. The measurement unit 21 measures the shape of the irradiation object TAR and the distance from each irradiation unit 13. For example, the measurement unit 21 can be configured with a camera and a captured image analysis unit.

[0021] As shown in FIG. 6 , the control unit 15 adjusts the distribution amount of the ultraviolet light by adjusting the branching ratio of the branching unit 12. In this example, the branching unit 12 is configured to perform "intensity branching" of the ultraviolet light. For example, the branching unit 12 is a variable branching ratio coupler. The control unit 15 controls the branching ratio of the branching unit 12 to control the intensity of the ultraviolet light output from each irradiation unit 13. Specifically, the control unit 15 controls the branching ratio of the branching unit 12 so that the ultraviolet light irradiation intensity (accumulated irradiation amount) is uniform across the entire surface of the three-dimensional irradiation target TAR. For example, the control unit 15 increases the intensity of the ultraviolet light supplied to the irradiation unit that irradiates areas where the irradiated ultraviolet light is weak (such as areas that are easily shaded by obstacles in the light path or areas far from the irradiation unit) (in the case of FIG. 6 , the control unit 15 increases the intensity of the ultraviolet light supplied to the irradiation units 13-1 and 13-2). On the other hand, the control unit 15 weakens the intensity of the ultraviolet light supplied to the irradiation unit that irradiates areas where the irradiated ultraviolet light is strong (such as areas close to the irradiation unit) (in the case of Figure 6, the intensity of the ultraviolet light supplied to the irradiation unit 13-N is weakened).

[0022] As shown in FIG. 7 , the control unit 15 may adjust the distribution amount of the ultraviolet light at the timing of switching the branch unit 12 to each path. In this example, the branch unit 12 is configured to perform "switching" of the ultraviolet light. For example, the branch unit 12 is an optical switch. The control unit 15 controls the switching time of the optical switch to each path and the output time of the ultraviolet light from each irradiation unit 13. Specifically, the control unit 15 controls the switching time of the branch unit 12 so that the integrated light amount of the ultraviolet light is uniform across the entire surface of the three-dimensional irradiation target TAR. For example, the control unit 15 lengthens the supply time of ultraviolet light to the irradiation unit that irradiates areas where the irradiated ultraviolet light is weak (such as areas that are easily shaded by obstacles in the light path or areas far from the irradiation unit) (in the case of FIG. 7 , the supply time of ultraviolet light to the irradiation units 13-1 and 13-N-1 is lengthened). On the other hand, the control unit 15 shortens the time for which ultraviolet light is supplied to the irradiation unit that irradiates areas where the ultraviolet light is strong (such as areas close to the irradiation unit) (in the case of Figure 7, the time for which ultraviolet light is supplied to irradiation units 13-4 and 13-N is shortened).

[0023] 8 is a diagram illustrating an ultraviolet light irradiation system according to the present embodiment. This ultraviolet light irradiation system differs from the ultraviolet light irradiation system according to the first embodiment in that a measurement unit 21 measures the intensity of the ultraviolet light at each position on the surface of the irradiation target TAR.

[0024] The measurement unit 21 measures the light intensity of the ultraviolet light irradiated onto the irradiation object TAR. For example, the measurement unit 21 is an ultraviolet camera. The measurement unit 21 may also measure the light intensity of the ultraviolet light irradiated from each irradiation unit 13 and reflected by the irradiation object TAR.

[0025] Based on the light intensity measured by the measurement unit 21, the control unit 15 adjusts the distribution amount of the ultraviolet light by adjusting the branching ratio of the branching unit 12 as shown in FIG. 6 . Specifically, the control unit 15 controls the branching ratio of the branching unit 12 so that the ultraviolet light irradiation intensity (accumulated irradiation amount) is uniform across the entire surface of the three-dimensional irradiation target TAR. For example, the control unit 15 increases the intensity of ultraviolet light supplied to the irradiation unit that irradiates areas where the light intensity measured by the measurement unit 21 is weak (e.g., areas that are likely to be shaded by obstacles in the light path or areas far from the irradiation unit) (in the case of FIG. 6 , the control unit 15 increases the intensity of ultraviolet light supplied to the irradiation units 13-1 and 13-2). On the other hand, the control unit 15 decreases the intensity of ultraviolet light supplied to the irradiation unit that irradiates areas where the light intensity measured by the measurement unit 21 is strong (e.g., areas close to the irradiation unit) (in the case of FIG. 6 , the control unit 15 decreases the intensity of ultraviolet light supplied to the irradiation unit 13-N).

[0026] Based on the light intensity measured by the measurement unit 21, the control unit 15 adjusts the distribution amount of the ultraviolet light by adjusting the switching time of the branching unit 12, as shown in FIG. 7 . Specifically, the control unit 15 controls the switching time of the branching unit 12 so that the integrated light amount of ultraviolet light is uniform across the entire surface of the three-dimensional irradiation target TAR. For example, the control unit 15 lengthens the supply time of ultraviolet light to the irradiation unit that irradiates areas where the light intensity measured by the measurement unit 21 is weak (e.g., areas that are likely to be shaded by obstacles in the light path or areas far from the irradiation unit) (in the case of FIG. 7 , the control unit 15 lengthens the supply time of ultraviolet light to the irradiation unit 13-1 and 13-N-1). On the other hand, the control unit 15 shortens the supply time of ultraviolet light to the irradiation unit that irradiates areas where the light intensity measured by the measurement unit 21 is strong (e.g., areas close to the irradiation unit) (in the case of FIG. 7 , the control unit 15 shortens the supply time of ultraviolet light to the irradiation unit 13-4 and 13-N).

[0027] 9 is a diagram illustrating a control method for controlling the ultraviolet light irradiation system described above. This control method is a control method for an ultraviolet light irradiation system in which ultraviolet light generated by an ultraviolet light source unit 11 is distributed by a branching unit 12 and irradiated onto an irradiation object TAR of any shape from a plurality of irradiation units 13 arranged around the irradiation object TAR, and is characterized by measuring the state of the irradiation object TAR (step S01), and adjusting the distribution amount of the ultraviolet light in the branching unit 12 based on the state of the irradiation object TAR so that the cumulative irradiation amount of the ultraviolet light at each position on the surface of the irradiation object TAR approaches uniformity (step S02).

[0028] (Effects) In an ultraviolet light irradiation system using a branched optical fiber, the present invention makes it possible to irradiate ultraviolet light uniformly regardless of the structure of a three-dimensional object, even when irradiating the object with complex shapes. This makes it possible to build a system that can sterilize or inactivate viruses on the entire surface of a three-dimensional object in the shortest possible time.

[0029] 11: Ultraviolet light source unit 12: Branching unit 13, 13-1, 13-2, ..., 13-N: Irradiation unit 15: Control unit 16: Optical fiber 21: Measurement unit

Claims

1. An ultraviolet light irradiation system comprising: an ultraviolet light source unit that generates ultraviolet light; a plurality of irradiation units that are arranged around an irradiation object of any shape and irradiate the ultraviolet light onto the irradiation object; a branching unit that distributes the ultraviolet light from the ultraviolet light source unit to each of the irradiation units; a measurement unit that measures a state of the irradiation object; and a control unit that adjusts the distribution amount of the ultraviolet light in the branching units so that the integrated irradiation amount of the ultraviolet light at each position on the surface of the irradiation object approaches uniformity based on the state of the irradiation object.

2. The ultraviolet light irradiation system according to claim 1, characterized in that the measurement unit grasps the shape of the object to be irradiated.

3. The ultraviolet light irradiation system according to claim 1, characterized in that the measurement unit measures the distance to the surface of the object to be irradiated for each of the irradiation units.

4. The ultraviolet light irradiation system according to claim 1, characterized in that the measurement unit measures the intensity of the ultraviolet light at each position on the surface of the object to be irradiated.

5. An ultraviolet light irradiation system according to any one of claims 1 to 4, characterized in that the control unit adjusts the distribution amount of the ultraviolet light by the branching ratio of the branching unit.

6. An ultraviolet light irradiation system as described in any one of claims 1 to 4, characterized in that the control unit adjusts the distribution amount of the ultraviolet light at the timing of switching to each route of the branching unit.

7. A control method for an ultraviolet light irradiation system in which ultraviolet light generated in an ultraviolet light source unit is distributed in a branching unit and the ultraviolet light is irradiated onto an irradiation object of any shape from multiple irradiation units arranged around the irradiation object, the control method comprising: measuring a state of the irradiation object; and adjusting the distribution amount of the ultraviolet light in the branching unit so that the cumulative irradiation amount of the ultraviolet light at each position on the surface of the irradiation object approaches uniformity based on the state of the irradiation object.

Images