WO2024105873A1 - Light spot shaper and optical transmission system - Google Patents

Abstract

The purpose of present invention is to provide a light spot shaper and an optical transmission system which can irradiate an irradiation-requiring area with concentrated light, and which can perform short and efficient light irradiation.　An optical transmission system (301) according to the present invention comprises: a light source unit (11) which outputs light (L1); an optical transmission path (26) through which the light (L1) propagates; an optical branching unit (12e) which branches the light that has propagated through the optical transmission path (26) to a plurality of branched optical fibers; and an irradiation unit (13) which has a light spot shaper (70) that uses the branched optical fibers as optical fibers (55) and which irradiates an irradiation target area (AR) with the light that has passed through the light spot shaper (70). The light spot shaper (70) is provided with an operation part (72) that applies a force to an optical fiber group (38) in which the plurality of optical fibers (55) are gathered such that the optical axis directions thereof are the same, and that changes the position of the optical fibers in a cross-section perpendicular to said optical axis directions.

Description

Optical spot shaper and optical transmission system

This disclosure relates to an optical spot shaper that can change the spot shape of irradiated light, and an optical transmission system equipped with the same.

There is an increasing demand for systems that use ultraviolet light to sterilize and inactivate viruses for the purpose of preventing infectious diseases. There are three main categories of such systems. In this specification, the term "sterilization, etc." refers to sterilization and inactivation of viruses.
(I) Mobile sterilization robot The product of Non-Patent Document 1 is an autonomous mobile robot that irradiates ultraviolet light. The robot can irradiate ultraviolet light while moving around a room in a building such as a hospital room, thereby automatically sterilizing a wide area without human intervention.
(II) Freestanding Air Purifier The product in Non-Patent Document 2 is a device that is installed on the ceiling or a predetermined location in a room and circulates the air in the room while sterilizing, etc. This device does not directly irradiate ultraviolet light and has no effect on the human body, so it is possible to sterilize, etc. with a high degree of safety.
(III) Portable sterilization device The product of Non-Patent Document 3 is a portable device equipped with an ultraviolet light source. A user can take the device to a desired area and irradiate ultraviolet light. Therefore, the device can be used in various places.

However, the devices described in the non-patent literature have the following problems.
(1) Economic Efficiency The product of Non-Patent Document 1 irradiates high-power ultraviolet light, so the device is large-scale and expensive. Therefore, the product of Non-Patent Document 1 has a problem that it is difficult to realize an economical system.
(2) Versatility With the product of Non-Patent Document 1, the areas to be irradiated with ultraviolet light are limited to areas where a robot can move/enter, making it difficult to irradiate narrow or deep areas with ultraviolet light.
The product of Non-Patent Document 2 sterilizes the circulated indoor air, and therefore cannot irradiate the location where sterilization is desired with ultraviolet light directly.
The product of Non-Patent Document 3 cannot irradiate ultraviolet light onto, for example, narrow pipes or areas where people cannot enter.
As described above, the products described in non-patent literature have a problem in that they lack the versatility to irradiate ultraviolet light anywhere.
(3) Operability The product of Non-Patent Document 3 is portable and can irradiate ultraviolet light in various locations. However, in order to obtain sufficient sterilization effects at the target location, the user is required to have skills and knowledge, and there are problems with operability.

To address these issues, an ultraviolet light irradiation system 300 using optical fibers as shown in FIG. 1 can be considered. In this ultraviolet light irradiation system, ultraviolet light is transmitted from the ultraviolet light source unit 11a using a thin and easily bendable optical fiber as the optical transmission path 16, and the ultraviolet light output from the tip of the optical fiber, which is the path 14, is irradiated to the irradiation target area AR where pinpoint sterilization is desired. Since ultraviolet light can be irradiated to any location simply by moving the irradiation unit 13 at the tip of the path 14, the versatility of the above issue (2) can be resolved. In addition, since there is no need to move or set up the ultraviolet light source, and no skills or knowledge are required of the user, the operability of the above issue (3) can also be resolved. Furthermore, by providing an optical distribution unit 12 such as an optical splitter in the optical transmission path 16 and configuring a system of P-MP (Point to Multipoint) such as FTTH (Fiber To The Home), multiple locations can be sterilized by sharing a single light source. This also solves the economic problem of problem (1) above.

On the other hand, not only P-MP configurations, but ultraviolet light irradiation systems in general have the following problems.
Deep ultraviolet light, which is used in systems for sterilization using ultraviolet light, can cause cataracts and skin cancer when it is irradiated onto the eyes or skin of humans and other animals. For this reason, in spaces where people and animals are constantly present, such as residential spaces, measures are required such as not irradiating ultraviolet light onto objects to be avoided, such as people and animals, or using ultraviolet light with a low illuminance that is not harmful to such objects.

If a very low power is used to irradiate the target in order to avoid exposing it to ultraviolet light, it will take a long time to complete the inactivation, making it difficult to apply to areas where inactivation is required in a short period of time.

In addition, an ultraviolet light irradiation system equipped with optical fiber irradiates the target irradiation area with ultraviolet light in a concentric pattern with the core of the optical fiber at the center. The target irradiation area may include not only areas where sterilization, etc. is required (hereinafter, such areas will be referred to as "irradiation-required areas"), but also areas where sterilization, etc. is not required or areas where irradiation of ultraviolet light should be avoided (hereinafter, such areas will be referred to as "non-irradiation target areas"). In an ultraviolet light irradiation system equipped with optical fiber, even if an attempt is made to irradiate the irradiation-required area with ultraviolet light, the entire irradiation target area is irradiated with ultraviolet light, reducing the illuminance of the irradiation-required area. In order to achieve the expected sterilization effect, it is necessary to increase the power of the ultraviolet light output by the light source unit or extend the irradiation time, which reduces the energy efficiency for sterilization, etc.

In other words, ultraviolet light irradiation systems have had the problem that it is difficult to concentrate ultraviolet light on an area requiring irradiation and perform sterilization, etc. efficiently in a short period of time.
Therefore, in order to solve the above problems, the present invention aims to provide a light spot shaper and an optical transmission system that can irradiate light in a concentrated manner onto an area requiring irradiation, and can perform efficient light irradiation in a short period of time.

In order to achieve the above object, the light spot shaper of the present invention is provided with a mechanism for changing the physical arrangement of each of a plurality of optical fibers, thereby changing the light spot shape in the irradiation target area. In this specification, the "light spot shape" refers to the shape of the light irradiated on a surface perpendicular to the optical axis. The light spot shape is, for example, a circle, an ellipse, a polygon, or an irregular shape like an amoeba (see FIG. 14).

Specifically, the light spot shaper of the present invention is provided with an action part that applies force to an optical fiber group in which multiple optical fibers are gathered together so that their optical axis directions are the same, and changes the position of the optical fibers in a cross section perpendicular to the optical axis direction.
For example, the action portion is a structure that applies the force to each of the optical fibers and changes the position of each of the optical fibers.
The action portion may be structured to apply the force to the entire optical fiber group, thereby changing the shape of the optical fiber group in the cross section.

The light spot shaper according to the present invention can suppress light irradiation to non-irradiation target areas by the function of the action portion, and can concentrate the irradiation light on the irradiation-required area by the amount of the suppressed optical power.
For example, if the irradiation light is ultraviolet light, irradiation of the human body can be avoided. Also, since there is no need to operate at such low power that exposure of the human body to ultraviolet light can be ignored, sterilization of the irradiation target area (irradiation required area) can be completed in a short time. Furthermore, ultraviolet light can be suppressed in areas other than the irradiation target area, and ultraviolet light can be concentrated and irradiated to the irradiation required area, improving energy efficiency for sterilization and other effects.

Therefore, the present invention can provide a light spot shaper that can irradiate light in a concentrated manner to an area requiring irradiation, and can perform efficient light irradiation in a short period of time.

A first optical transmission system according to the present invention comprises:
A light source unit that outputs light;
an optical transmission path for propagating the light;
an optical branching unit that branches the light propagated through the optical transmission line into a plurality of branch optical fibers;
an irradiation unit having the light spot shaper with the branched optical fiber as the optical fiber, and irradiating the light passing through the light spot shaper onto an irradiation target area;
Equipped with.

A second optical transmission system according to the present invention comprises:
A light source unit that outputs light;
an optical transmission line that propagates the light through a plurality of cores of an optical bundle formed by bundling a plurality of single-core optical fibers;
a separation unit that separates the bundle optical fiber into the single-core optical fiber;
an irradiation unit that has the light spot shaper that uses the single-core optical fiber disassembled by the separation unit as the optical fiber, and irradiates the light that has passed through the light spot shaper onto an irradiation target area;
Equipped with.

A third optical transmission system according to the present invention comprises:
A light source unit that outputs light;
an optical transmission line that propagates the light through a plurality of cores of an optical bundle formed by bundling a plurality of single-core optical fibers;
a separation and branching unit that separates the bundle optical fiber into the single-core optical fibers and groups them into N groups (N is an integer of 2 or more);
N irradiation units each irradiating N irradiation target areas with light propagating through the single-core optical fibers grouped into the group;
Equipped with
At least one of the irradiation units has a light spot shaper that uses the single-core optical fibers grouped together in the group as the optical fiber, and is characterized in that the light that has passed through the light spot shaper is irradiated onto the irradiation target area.

The first to third optical transmission systems are equipped with the optical spot shaper. Therefore, it is possible to provide an optical transmission system that can irradiate light in a concentrated manner to an area requiring irradiation, and can perform efficient light irradiation in a short time.

The first to third optical transmission systems include
a sensor unit that detects whether or not an object to be avoided from being exposed to the light is present in an area including the irradiation object area and outputs sensor information;
a control unit that instructs the action unit of the light spot shaper on how to apply the force based on the sensor information from the sensor unit;
The present invention is characterized by further comprising:
Since the present optical transmission system is equipped with a sensor unit and a control unit, even if the positions of the irradiation-required area and the non-irradiation area within the irradiation target area change, the light spot shape can be changed accordingly.

In addition, the second and third optical transmission systems are
a control unit that outputs a control signal to the action unit of the light spot shaper to instruct how to apply the force;
The control unit is characterized in that it transmits the control signal to the light spot shaper by utilizing at least one of the cores of the bundle optical fiber.

The control signal can be transmitted by wire or wirelessly, but it can also be transmitted by optical communication using the core of the optical transmission line. In this case, resources can be used efficiently if the outer core of the optical transmission line, which transmits a relatively small amount of optical power, is used for optical communication.

In other words, the present invention is a light irradiation method in which light propagating through an optical fiber group, in which multiple optical fibers are gathered so that their optical axis directions are the same, is emitted as irradiation light from the end of the optical fiber group, and is characterized in that a force is applied to the optical fiber group, changing the position of the optical fiber in a cross section perpendicular to the optical axis direction, thereby changing the spot shape of the irradiation light.

Here, the light irradiation method according to the present invention comprises:
The present invention can further comprise generating sensor information that detects whether or not there is an object to be avoided that should be avoided from being exposed to the light in an area including an irradiation target area to which the irradiation light is irradiated, and instructing how to apply the force to the optical fiber group based on the sensor information.

The above inventions can be combined as much as possible.

The present invention provides a light spot shaper and optical transmission system that can irradiate light in a concentrated manner on an area requiring irradiation, and can perform efficient light irradiation in a short period of time.

FIG. 1 is a diagram illustrating a problem to be solved by the present invention. FIG. 2 is a diagram illustrating a light spot shaper according to the present invention. FIG. 2 is a diagram illustrating a light spot shaper according to the present invention. FIG. 2 is a diagram illustrating a light spot shaper according to the present invention. 1A to 1C are diagrams illustrating the effect of a light spot shaper according to the present invention. 1 is a diagram illustrating an optical transmission system according to the present invention; FIG. 2 is a diagram illustrating the structure of an optical fiber. 1 is a diagram illustrating an optical transmission system according to the present invention; FIG. 1 is a diagram for explaining the advantages of an optical fiber bundle. 1 is a diagram illustrating an optical transmission system according to the present invention; 1 is a diagram illustrating an optical transmission system according to the present invention; 1 is a diagram illustrating an optical transmission system according to the present invention; 1 is a diagram illustrating an optical transmission system according to the present invention; FIG. 13 is a diagram illustrating a spot shape.

The following describes an embodiment of the present invention with reference to the attached drawings. The embodiment described below is an example of the present invention, and the present invention is not limited to the following embodiment. Note that components with the same reference numerals in this specification and drawings are mutually identical.

(Embodiment 1)
FIG. 2 is a diagram illustrating the light spot shaper 70 of the present embodiment. The light spot shaper 70 is
The optical fiber group includes an action portion that applies a force to an optical fiber group in which a plurality of optical fibers are gathered so that their optical axes are aligned, thereby changing the positions of the optical fibers in a cross section perpendicular to the optical axis direction.

FIG. 3 is a diagram for explaining the structure of the action unit 72. The action unit 72 is characterized by applying the force to each of the optical fibers 55, changing the position of each optical fiber 55. Specifically, the action unit 72 includes a housing 72a and an electromagnet 72b. A plurality of optical fibers 55 are arranged in a movable state inside the housing 72a. An electromagnet 72b is attached to the side of each optical fiber 55, and power is applied by an electric circuit (not shown). The electromagnet 72b to which power is applied generates a magnetic force between itself and the electromagnet 72b of another nearby optical fiber 55. The position of each optical fiber 55 is shifted by the repulsive or attractive force caused by the magnetic force. In other words, the light spot shaper 70 including the action unit 72 of the structure shown in FIG. 3 changes the shape of the light spot by increasing or decreasing the magnetic force of the electromagnet 72b by electrical control, and narrowing or widening the gap between the optical fibers 55.

FIG. 4 is a diagram illustrating another structure of the action unit 72. The action unit 72 is characterized by applying the force to the entire optical fiber group 38, changing the shape of the optical fiber group 38 in cross section. Specifically, the action unit 72 includes a housing 72a, a band 72d that contains multiple optical fibers 55, and a pressing unit 72c that applies force to the band 72d to apply force to the optical fiber group 38. The multiple optical fibers 55 are loosely bundled in the band 72d to the extent that the shape of the optical fiber group 38 in cross section changes when a force is applied from the outside.

Here, the "shape of the optical fiber group 38 in cross section" means the following.
The "cross section" refers to a plane perpendicular to the optical axis direction of the optical fiber 55. Strictly speaking, the optical axis direction of each optical fiber 55 is different, but here, the average direction of the optical axis directions of all the optical fibers 55 is defined as the optical axis direction of the optical fiber 55.
The "shape of the optical fiber group 38" is the shape of a polygon formed by connecting the centers of adjacent optical fibers 55 that are currently the outermost optical fibers 55 among all the optical fibers 55.

The optical fiber group 38 passes through the inside of the housing 72a. The inside of the housing 72a is provided with multiple pressing parts 72c, which are structured to press the optical fiber group 38 from above the band 72d. The shape of the optical fiber group 38 changes depending on the pressing part 72c used for pressing and the pressing force. In other words, the light spot shaper 70, which has an action part 72 with the structure of Figure 4, adjusts the position and inclination of the tip of the pressing part 72c by electrical control so that the shape of the optical fiber group 38 becomes the desired shape, thereby changing the light spot shape.

FIG. 5 is a diagram explaining the effect of the light spot shaper 70. The light spot shaper 70 is provided in the irradiation unit 13. The light L2 emitted from the irradiation unit 13 irradiates the irradiation target area AR. There are an irradiation target 91 to be irradiated with the light L2 and an avoidance target 92 to be avoided from being irradiated with the light L2. When the irradiation unit 13 does not have the light spot shaper 70, or when the light spot shaper 70 does not shape the light spot, the irradiation range L2a of the light L2 becomes almost a perfect circle. In this state, the light L2 is irradiated not only to the irradiation target 91 but also to the avoidance target 92. On the other hand, when the irradiation unit 13 has the light spot shaper 70 and shapes the light spot to avoid irradiation of the avoidance target 92, the light L2 becomes the irradiation range L2b.

In this way, the light spot shaper 70 matches the spot shape of the light L2 to the irradiation target 91, and also adjusts the light spot shape so that the irradiation range is expanded and does not hit the avoidance target 92. By equipping the irradiation unit 13 with the light spot shaper 70, it becomes possible to concentrate the irradiation of the light L2 only on the irradiation target 91, and the efficiency of the light irradiation can be improved. In addition, it is possible to avoid the irradiation of the light on the avoidance target 92, and safety can be ensured.

(Embodiment 2)
FIG. 6 is a diagram illustrating an optical transmission system 301 according to the present embodiment. The optical transmission system 301 includes:
A light source unit 11 that outputs light L1;
an optical transmission path 26 that propagates light L1;
an optical branching unit 12e that branches the light propagated through the optical transmission line 26 into a plurality of branch optical fibers;
an irradiation unit 13 having the light spot shaper 70 described in the first embodiment in which the branch optical fiber is the optical fiber 55, and irradiating the light passing through the light spot shaper 70 to an irradiation target area AR;
Equipped with.

The light source unit 11 is an LED (Light Emitting Diode) that outputs ultraviolet light, visible light, or infrared light L1. Note that the light source unit 11 is not limited to an LED, and may be a light source (for example, an incandescent lamp or a discharge lamp) having the following optical characteristics.
- There is variation in wavelength, amplitude, or phase.
・Light is scattered.
・It is a natural release.

In this embodiment, an optical system 11c is present that couples the light L1 from the light source unit 11 to one end T1 of the optical transmission path 26, but depending on the spot diameter of the light L1 output by the light source unit 11 and the diameter of one end T1 of the optical transmission path 26, the optical system 11c may not be necessary.

The optical transmission line 26 is an optical fiber that propagates light L1 inputted to one end T1 to the other end T2. Fig. 7 is a cross-sectional view for explaining the structure of the optical fiber used in the optical transmission line 26. In addition to a solid optical fiber using a general additive as shown in Fig. 7(1), an optical fiber having a hole structure as shown in Fig. 7(2) to (4), an optical fiber having multiple core regions as shown in Fig. 7(5) and (6), or an optical fiber having a structure combining these (Fig. 7(7) to (10)) may be used.
(1) Solid-core Optical Fiber This optical fiber has one solid core 52 in a cladding 60, the solid core having a higher refractive index than the cladding 60. "Solid" means "not hollow." A 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 number of holes 53 arranged around the solid core 52 in a cladding 60. The medium of the holes 53 is air, and the refractive index of air is sufficiently smaller than that of silica-based glass. Therefore, the hole-assisted optical fiber has a function of returning light that has leaked from the core 52 due to bending or the like back to the core 52, and is characterized by small bending loss.
(3) Hole-structure optical fiber This optical fiber has a group of holes 53a of a plurality of holes 53 in the cladding 60, and has an effective refractive index lower than that of the host material (glass, etc.). This structure is called a photonic crystal fiber. This structure can have a structure in which a high refractive index core with a changed refractive index does not exist, and the region 52a surrounded by the holes 53 can be used as an effective core region to confine light. Compared to optical fibers with a solid core, photonic crystal fibers can reduce the effects of absorption and scattering loss due to additives in the core, and can achieve optical properties that cannot be achieved with solid optical fibers, such as reduced bending loss and control of nonlinear effects.
(4) Hollow-core optical fiber: In this optical fiber, the core region is made of air. By forming a photonic band gap structure with multiple air holes in the cladding region or an anti-resonant structure with a thin glass wire, light can be confined to the core region. This optical fiber has a small nonlinear effect and can supply high-output or high-energy laser.
(5) Coupled-core optical fiber In this optical fiber, multiple solid cores 52 with a high refractive index are arranged closely together in a cladding 60. This optical fiber guides light by optical wave coupling between the solid cores 52. A coupled-core optical fiber can disperse and transmit light in proportion to the number of cores, allowing for high power output for efficient sterilization, etc. In addition, a coupled-core optical fiber has the advantage of being able to mitigate fiber deterioration caused by ultraviolet rays and extend the lifespan.
(6) Solid-core type multi-core optical fiber In this optical fiber, multiple solid cores 52 with a high refractive index are arranged at a distance from each other in the cladding 60. In this optical fiber, the optical wave coupling between the solid cores 52 is sufficiently small so that the influence of the optical wave coupling can be ignored, and light is guided in this state. Therefore, the solid-core type multi-core optical fiber has the advantage that each core can be treated as an independent waveguide.
(7) Hole-assisted multi-core optical fiber This optical fiber has a structure in which a plurality of the hole structures and core regions described above in (2) are arranged in the cladding 60.
(8) Hole-Structure-Type Multi-Core Optical Fiber This optical fiber has a structure in which a plurality of the hole structures described above in (3) are arranged in the cladding 60.
(9) Hollow-core-type multi-core optical fiber This optical fiber has a structure in which a plurality of the above-mentioned hole structures (4) are arranged in the cladding 60.
(10) Coupled-core-type multi-core optical fiber This optical fiber has a structure in which a plurality of the coupled-core structures described above in (5) are arranged in the cladding 60.

The optical branching unit 12e connects the optical transmission path 26 to a plurality of branch optical fibers (optical fibers 55), and branches the light transmitted by the optical transmission path 26 to each of the branch optical fibers (optical fibers 55). The optical branching unit 12e is, for example, a coupler, a splitter, or a fan-out device.

The irradiation unit 13 irradiates the irradiation target area AR with light that has propagated through the optical fiber group 38, which includes multiple optical fibers 55, as light L2. The irradiation unit 13 has a light spot shaper 70, as described in the first embodiment, which changes the shape of the optical fiber group 38 in cross section and shapes the light L2 into an arbitrary spot shape.

As described in FIG. 5, the optical transmission system 301 uses the light spot shaper 70 to match the spot shape of the light L2 to the irradiation target 91, and can adjust the light spot shape so that the irradiation range is expanded and does not hit the avoidance target 92. Furthermore, by providing the irradiation unit 13 with the light spot shaper 70, it becomes possible to concentrate the irradiation of the light L2 only on the irradiation target 91, and the efficiency of the light irradiation can be improved. Furthermore, it is possible to avoid the irradiation of the light to the avoidance target 92, and safety can be ensured.

(Embodiment 3)
FIG. 8 is a diagram illustrating an optical transmission system 302 according to the present embodiment. The optical transmission system 302 includes:
a light source unit 11 that outputs light;
an optical transmission line 26 that propagates the light through a plurality of cores of an optical bundle 36 in which a plurality of single-core optical fibers 51 a are bundled;
a separation unit 12c for separating the bundle optical fiber 36 into single-core optical fibers 51a;
an irradiation unit 13 having the light spot shaper 70 described in the first embodiment, which uses the single-core optical fiber 51 a separated by the separation unit 12 c as the optical fiber 55, and which irradiates the light L2 passing through the light spot shaper 70 onto an irradiation target area AR;
Equipped with.

In the optical transmission system 302, the optical fiber of the optical transmission path 26 of the optical transmission system 301 described in FIG. 6 is replaced with an optical fiber bundle 36, and the optical branching section 12e is replaced with a separation section 12c.
8, the bundle optical fiber 36 is a bundle of a plurality of single-core optical fibers 51a. One end T1 is irradiated with light L1 from the light source unit 11. On the other hand, at the other end T2, the single-core optical fibers 51a are disassembled by a separation unit 12c described later, and the individual single-core optical fibers 51a are connected to the irradiation unit 13 as optical fibers 55.

The advantage of using the bundle optical fiber 36 in the optical transmission line 26 will be described with reference to FIG.
When the light source unit 11 is an LED, the light emitting surface is wider than that of a laser, so even if the light L1 output from the LED is coupled to one single-core optical fiber 51a, the core area in the cross section is narrow, and most of the light is not coupled, resulting in low coupling efficiency (FIG. 9(A)). This is the same even if the light L1 output from the LED is narrowed down by an optical system such as a lens (FIG. 9(B)). In other words, when an LED is used for the light source unit 11, there is a problem that most of the output power of the light source unit 11 cannot be effectively utilized. This problem is not limited to optical transmission systems that transmit ultraviolet light, but is a common problem in optical transmission systems that transmit infrared light and visible light.

Here, if light is coupled to multiple cores present in the cross section, such as in a multi-core optical fiber (MCF) or a bundled optical fiber consisting of multiple single-core optical fibers, the coupling efficiency is improved and the waste of output power from the light source can be reduced (Figure 9 (C)).

As described in FIG. 5, the optical transmission system 302 uses the light spot shaper 70 to match the spot shape of the light L2 to the irradiation target 91, and can adjust the light spot shape so that the irradiation range is expanded and does not hit the avoidance target 92. Furthermore, by providing the irradiation unit 13 with the light spot shaper 70, it becomes possible to concentrate the irradiation of the light L2 only on the irradiation target 91, and the efficiency of the light irradiation can be improved. Furthermore, it is possible to avoid the irradiation of the light to the avoidance target 92, and safety can be ensured.

(Embodiment 4)
FIG. 10 is a diagram illustrating an optical transmission system 303 according to the present embodiment. The optical transmission system 303 includes:
A light source unit 11 that outputs light L1;
an optical transmission line 26 that transmits light L1 through a plurality of cores of a bundle optical fiber 36 in which a plurality of single-core optical fibers 51a are bundled;
a separation/branching unit 12f for separating the bundle optical fiber into the single-core optical fibers and grouping the single-core optical fibers into N groups (N is an integer of 2 or more);
N irradiation units 13 each irradiating N irradiation target areas ARn (n is an integer from 1 to N) with light propagating through the grouped single-core optical fibers 51a;
Equipped with
At least one of the irradiation units 13 has the light spot shaper 70 described in embodiment 1 in which the single-core optical fibers 51a grouped together are used as optical fibers 55, and is characterized in that the light L2 that passes through the light spot shaper 70 is irradiated onto the irradiation target area ARn.

The optical transmission system 303 is a P-MP configuration of the optical transmission system 302 described in FIG. 8, using a splitter 12f. The splitter 12f connects the optical transmission path 26 (bundle optical fiber 36) and N paths 14 (optical fiber group 38), and splits the light propagating through the bundle optical fiber 36 as a whole into the optical fiber group 38 of each path 14. The number I of single-core optical fibers 51a bundled in the bundle optical fiber 36 and the number J of optical fibers 55 included in the optical fiber group 38 may be the same or different. The splitter 12f is, for example, a coupler, a splitter, or a fan-out device.

5, the optical transmission system 303 can also use the light spot shaper 70 to match the spot shape of the light L2 to the irradiation target 91, and can adjust the spot shape of the light so that the irradiation range is expanded and the light does not hit the avoidance target 92. Furthermore, by providing the irradiation unit 13 with the light spot shaper 70, it becomes possible to intensively irradiate the light L2 only to the irradiation target 91, and the efficiency of light irradiation can be improved. Furthermore, it is possible to avoid irradiating the avoidance target 92 with light, and safety can be ensured.
Furthermore, the optical transmission system 303 has the advantage that the light L1 from one light source unit 11 can be shared by a plurality of irradiation target areas ARn, thereby reducing system costs.

It should be noted that not all irradiation units 13 need to have a light spot shaper 70. It is sufficient to provide a light spot shaper 70 in the irradiation unit 13 responsible for the irradiation target area ARn where light spot shaping is required.

(Embodiment 5)
The optical transmission systems (301 to 303) described in Fig. 6, Fig. 8, and Fig. 10 may further include a control unit 15c that outputs a control signal instructing the action unit 72 of the light spot shaper 70 how to apply the force. Fig. 11 is a diagram illustrating an optical transmission system 302 including the control unit 15c as an example. The optical transmission system 302 in Fig. 11 can change the spot shape of the light L2 depending on the condition of the irradiation target area AR.

Information on the spot shape of light L2 to be shaped by light spot shaper 70 is input to control unit 15c (this may be input by an operator, or may be information from a sensor, etc., as described below). Based on this information, control unit 15c outputs a control signal to light spot shaper 70 to create the desired light spot shape. Light spot shaper 70 receives the control signal from control unit 15c and shapes the spot shape of light L2. The control signal from control unit 15c to light spot shaper 70 may be an electrical signal via an electric wire, an optical signal via an optical fiber, or a wireless signal such as radio waves or light.

The optical transmission system (301-303) equipped with the control unit 15c can optimize the light spot shape according to the conditions of the irradiation target 91 and the avoidance target 92 when the position of the avoidance target 92 changes over time within the irradiation target area (AR or ARn) due to human movement or the irradiation target 91 is a moving object and the position of the irradiation target 91 changes over time.

Here, the control unit 15c may be disposed away from the light spot shaper 70. This allows remote control of shaping the light spot. Figure 12 is a diagram illustrating a configuration in which the control unit 15c is disposed away from the light spot shaper 70.

FIG. 12(A) is a diagram explaining an optical transmission system 302 in which the control unit 15c is disposed on the light source unit 11 side and is connected to the light spot shaper 70 using a control signal transmission cable Cs. The control signal from the control unit 15c to the light spot shaper 70 may be not only an electrical signal via an electric wire that is the control signal transmission cable Cs or an optical signal via an optical fiber, but also a wireless signal such as an electric wave or light that does not use the control signal transmission cable Cs. The optical transmission systems 301 and 303 can also adopt this configuration.

If the optical transmission path 26 is a bundle optical fiber 36, the configuration can be as shown in FIG. 12B. FIG. 12B is a diagram for explaining an optical transmission system 302 in which the control unit 15c transmits the control signal to the light spot shaper 70 using at least one of the cores of the bundle optical fiber 36. In the optical transmission system 302 in FIG. 12B, one of the cores of the bundle optical fiber 36 is allocated for control signal transmission, and the control unit 15c outputs a control signal to the light spot shaper 70 using the one core. The separation unit 12c converts the light (control signal) of the one core into an electrical signal and outputs it to a control signal transmission cable Cs connected to the light spot shaper 70. Since there is no need to prepare a separate control signal transmission cable for the section of the optical transmission path 26, there is an effect of reducing system costs.
The control signal from the control unit 15c to the light spot shaper 70 can be varied as follows.
The section from the control unit 15c to the separation unit 12c (particularly the portion transmitting the bundle fiber 36)
Since there are no functional parts capable of photoelectric conversion or wireless transceivers along the way, the control signals are only optical signals, and the cable Cs for transmitting control signals in this section is optical fiber.
The section from the separation unit 12c to the light spot shaper 70 The signal may be not only an electrical signal via an electric wire that is the control signal transmission cable Cs, or an optical signal via an optical fiber, but also a wireless signal such as radio waves or light that does not use the control signal transmission cable Cs.

This configuration can also be adopted in the optical transmission system 303, which is a P-MP. In this case, the single-core optical fibers 51a bundled in the bundle optical fiber 36 are allocated for each path 14 for control signal transmission. In other words, if there are N paths 14, the number of single-core optical fibers 51a allocated for control signal transmission will also be N. On the other hand, by multiplexing the control signals to each path 14 in the section of the optical transmission path 26, only one of the single-core optical fibers 51a bundled in the bundle optical fiber 36 can be used for the control signal.
As described above, the control signal is transmitted via electric wire, optical fiber, or wirelessly between the separation unit 12c or the separation branching unit 12f and the irradiation unit 13. However, if the control signal transmission cable Cs is optical fiber, one optical fiber 55 of the optical fiber group 38 may be allocated for transmitting the control signal.

(Embodiment 6)
The optical transmission systems (301 to 303) described in FIG. 6, FIG. 8, and FIG. 10 are as follows:
A sensor unit 31 that outputs sensor information indicating whether or not an avoidance target 92 that should be avoided from being exposed to the light L2 is present in an area including an irradiation target area (AR or ARn);
a control unit that instructs an action unit of the light spot shaper on how to apply the force based on the sensor information from the sensor unit;
The present invention is characterized by further comprising:

FIG. 13 is a diagram illustrating an example of an optical transmission system 302 equipped with a sensor unit 31 and a control unit 15c. The optical transmission system 302 in FIG. 13 can change the shape of the light spot based on sensor information from the sensor unit 31 (e.g., position information of an object to be avoided 92 within the irradiation target area AR).

The sensor unit 31 detects the presence or absence and movement of each irradiation target area AR and an avoidance target (such as a person or an animal) H in the vicinity thereof. For example, the sensor unit 31 acquires temperature using a thermometer, infrared rays using an infrared sensor, images using a camera, light using LiDAR (Light Detection and Ranging), etc., and performs information processing (shape, face, fingerprint, veins, iris, etc.) to detect the presence or absence and movement of an avoidance target.
The sensor unit 31 then notifies the control unit 15c of the detection result as sensor information. The notification to the control unit 15c may be made by wire or wirelessly.

The control unit 15c outputs a control signal to the light spot shaper 70 to form the desired light spot shape based on the sensor information from the sensor unit 13. The light spot shaper 70 receives a control signal from the control unit 15c and shapes the spot shape of the light L2.

The optical transmission system (301-303) equipped with the control unit 15c can identify the position of the irradiation target 91 or the avoidance target 92 within the irradiation target area (AR or ARn) by sensing, and can optimize the spot shape of the light L2 by tracking their movements in real time.

That is, the optical transmission system (301 to 303) performs light irradiation using the following light irradiation method.
This light irradiation method is a method in which light that has propagated through an optical fiber group 38 in which a plurality of optical fibers 55 are gathered so that their optical axis directions are the same is emitted as irradiation light L2 from the end of the optical fiber group 38, and is characterized in that a force is applied to the optical fiber group 38 to change the position of the optical fiber 55 in a cross section perpendicular to the optical axis direction, thereby changing the spot shape of the irradiation light L2.

here,
It is preferable to further perform the following: generating sensor information that detects whether or not there is an avoidance target H that should be avoided from being exposed to the light in an area including the irradiation target area (AR or ARn) where the irradiation light L2 is irradiated; and instructing how to apply the force to the optical fiber group 38 based on the sensor information.

11: Light source unit 11a: Ultraviolet light source unit 11c: Optical system 12: Light branching unit (equal branching)
12c: Separation section 12e: Optical branching section 12f: Separation and branching section 13, 13-1, ..., 13-n, ..., 13-N: Irradiation section 14: Path 15c: Control section 16: Optical transmission path 26: Optical transmission path 31: Sensor section 36: Bundle optical fiber 38: Optical fiber group 51a: Single-core optical fiber 52: Solid core 52a: Region 53: Hole 53a: Hole group 55: Single-core optical fiber 60 of path: Cladding 70: Light spot shaper 72: Action section 72a: Housing 72b: Electromagnet 72c: Pressing section 72d: Bands 300 to 303: Optical transmission system L1, L2: Light AR, AR1, AR2, ..., ARn, ..., ARN: Irradiation target area

Claims (8)

1. A light spot shaper that applies force to a group of optical fibers in which multiple optical fibers are gathered together so that the optical axis direction is the same, and has an action part that changes the position of the optical fibers in a cross section perpendicular to the optical axis direction.
2. The optical spot shaper of claim 1, characterized in that the action unit applies the force to each of the optical fibers, changing the position of each of the optical fibers.
3. The optical spot shaper of claim 1, characterized in that the action part applies the force to the entire optical fiber group, changing the shape of the optical fiber group in the cross section.
4. A light source unit that outputs light;
   an optical transmission path for propagating the light;
   an optical branching unit that branches the light propagated through the optical transmission line into a plurality of branch optical fibers;
   an irradiation unit having the light spot shaper according to claim 1 , the light spot shaper being the branched optical fiber, and irradiating the light passing through the light spot shaper onto an irradiation target area;
   An optical transmission system comprising:
5. A light source unit that outputs light;
   an optical transmission line that propagates the light through a plurality of cores of an optical bundle formed by bundling a plurality of single-core optical fibers;
   a separation unit that separates the bundle optical fiber into the single-core optical fiber;
   an irradiation unit having the light spot shaper according to claim 1 , the light spot shaper being the single-core optical fiber separated by the separation unit, and irradiating the light passing through the light spot shaper onto an irradiation target area;
   An optical transmission system comprising:
6. A light source unit that outputs light;
   an optical transmission line that propagates the light through a plurality of cores of an optical bundle formed by bundling a plurality of single-core optical fibers;
   a separation and branching unit that separates the bundle optical fiber into the single-core optical fibers and groups them into N groups (N is an integer of 2 or more);
   N irradiation units each irradiating N irradiation target areas with light propagating through the single-core optical fibers grouped into the group;
   Equipped with
   An optical transmission system characterized in that at least one of the irradiation units has a light spot shaper as described in claim 1, in which the single-core optical fibers grouped together in the group are the optical fibers, and the light that has passed through the light spot shaper is irradiated onto the irradiation target area.
7. a sensor unit that detects whether or not an object to be avoided from being exposed to the light is present in an area including the irradiation object area and outputs sensor information;
   a control unit that instructs the action unit of the light spot shaper on how to apply the force based on the sensor information from the sensor unit;
   7. The optical transmission system according to claim 4, further comprising:
8. A light irradiation method for emitting light propagating through an optical fiber group, in which a plurality of optical fibers are gathered so that their optical axes are aligned, as irradiation light from an end of the optical fiber group, comprising:
   A light irradiation method comprising the steps of: applying a force to the optical fiber group; and changing the position of the optical fibers in a cross section perpendicular to the optical axis direction, thereby changing the spot shape of the irradiation light.

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