Patent Application
20220308295
The present disclosure relates to a circuit board with an optical path conversion component and a wiring module for mounting on a circuit board. The present application claims the benefit of the priority based on Japanese Patent Application No. 2020-073428 filed on Apr. 16, 2020, the entire contents described in the application is incorporated herein by reference.
Patent Literature 1 discloses a technique regarding an optical connector. The optical connector is a horizontal optical connector that connects a plurality of optical fibers in parallel to the connection target surface, and achieves optical coupling between the optical fiber and a photoelectric conversion element in a state in which the optical connector is mounted on a substrate on which the photoelectric conversion element is disposed. In an optical transmission cable connected to the optical connector, a plurality of optical fibers have a direction along the substrate surface as a main arrangement direction.
A circuit board with an optical path conversion component according to an embodiment includes a circuit board having a main surface, an optical path conversion component connected to the circuit board, and one or more first fiber ribbons. Each of the one or more first fiber ribbons has a first end and a second end, and includes a plurality of optical fibers optically coupled to the optical path conversion component at the first end. The one or more first fiber ribbons extend in a direction crossing a normal of the main surface. The optical path conversion component has at least one channel group for each of the one or more first fiber ribbons and the at least one channel group includes a plurality of channels optically coupled respectively to the plurality of optical fibers. The plurality of channels are arranged in a direction crossing the main surface for each of the at least one channel group.
A wiring module for mounting on a circuit board according to an embodiment includes an optical path conversion component and one or more first fiber ribbons. The optical path conversion component has a bottom surface, and is configured to be mounted on a main surface of a circuit board. Each of the one or more first fiber ribbons has a first end and a second end, and includes a plurality of optical fibers optically coupled to the optical path conversion component at the first end. The optical path conversion component has at least one channel group for each of the one or more first fiber ribbons and the at least one channel group includes a plurality of channels optically coupled respectively to the plurality of optical fibers. The plurality of channels are arranged in a direction crossing the bottom surface for each of the at least one channel group.
In recent years, as the amount of signals transmitted and received between circuit boards or between a circuit board and another device increases, it has been thought about transmitting signals between these through an optical fiber. In this case, it is necessary to provide an optical device, such as a light receiving element, a light emitting element, or an optical waveguide, on the circuit board and to connect an optical fiber to the optical device. At this time, if the optical fiber is extended in a direction crossing a board surface of the circuit board, a large space is required for the arrangement of the optical fiber. Therefore, it is conceivable to extend the optical fiber in a direction along the board surface of the circuit board. In addition, when connecting a plurality of optical fibers and a plurality of optical devices, as shown in Patent Literature 1, a method of arranging the plurality of optical fibers with the direction along the board surface as a main arrangement direction can be considered.
In this case, however, if a fiber ribbon is used in order to improve the handling of the plurality of optical fibers, the following problem occurs. Generally, the fiber ribbon has a characteristic that the flexibility in a thickness direction, that is, a direction crossing an arrangement surface of the optical fiber, is high and the flexibility in a width direction, that is, the arrangement direction of the optical fiber, is low. When a plurality of optical fibers are arranged with the direction along the board surface as a main arrangement direction, the width direction of the fiber ribbon is along the board surface. Therefore, it is difficult to bend the fiber ribbon in a direction parallel to the board surface, which imposes restrictions on the design of the circuit board. Even if the fiber ribbon can be bent by twisting, there is a concern that the transmission loss may increase due to the torsional stress.
According to the present disclosure, it is possible to provide a circuit board with an optical path conversion component and a wiring module for mounting on a circuit board allowing a fiber ribbon to be easily bent in a direction parallel to the board surface of the circuit board.
First, embodiments of the present disclosure will be listed and described. A circuit board with an optical path conversion component according to an embodiment includes a circuit board having a main surface, an optical path conversion component connected to the circuit board, and one or more first fiber ribbons. Each of the one or more first fiber ribbons has a first end and a second end, and includes a plurality of optical fibers optically coupled to the optical path conversion component at the first end. The one or more first fiber ribbons extend in a direction crossing a normal of the main surface. The optical path conversion component has at least one channel group for each of the one or more first fiber ribbons and the at least one channel group includes a plurality of channels optically coupled respectively to the plurality of optical fibers. The plurality of channels are arranged in a direction crossing the main surface for each of the at least one channel group.
In the circuit board with an optical path conversion component, the first fiber ribbon extends from the optical path conversion component in a direction crossing the normal of the main surface of the circuit board in such a manner that the thickness direction crosses the normal of the main surface. Therefore, the first fiber ribbon can be easily bent in a direction parallel to the board surface (the main surface) of the circuit board. As a result, the restrictions on the design of the circuit board can be reduced, and the increase in transmission loss can be suppressed.
In the circuit board with an optical path conversion component described above, the optical path conversion component may have first optical paths extending from the plurality of channels in parallel with an optical axis of the respective optical fibers, second optical paths extending from an optical device provided on the main surface in a direction crossing the main surface, and an optical path converting portion for connecting the first and second optical paths to each other, and may optically couple the optical device to the plurality of optical fibers. Alternatively, the optical path conversion component may have first optical paths extending from the plurality of channels in parallel with an optical axis of the respective optical fibers, second optical paths extending from an optical device provided on the main surface in parallel with the main surface, and an optical path converting portion for connecting the first and second optical paths to each other, and may optically couple the optical device to the plurality of optical fibers. In any of these cases, the optical device on the circuit board can be efficiently coupled to the plurality of optical fibers. In these cases, the optical path converting portion may comprise at least one light reflecting surface.
In the circuit board with an optical path conversion component described above, the one or more first fiber ribbons extend in an inclination direction within 45° with respect to the main surface.
In the circuit board with an optical path conversion component described above, the at least one channel group may include at least two first channel groups arranged in a direction along the main surface. In this case, since the plurality of first fiber ribbons are arranged so as to overlap each other in the thickness direction, the wiring density of the first fiber ribbons can be increased. In addition, when a multi-fiber optical connector is attached to the second end of the one or more first fiber ribbons, the first fiber ribbons are easily bent in the arrangement direction. Therefore, regardless of the size of the multi-fiber optical connector, a plurality of channel groups of the optical path conversion component can be densely arranged. This can contribute to the miniaturization of the optical path conversion component.
In the circuit board with an optical path conversion component described above, the at least one channel group may include at least two second channel groups arranged in a direction crossing the main surface. In this case, the space on the circuit board can be effectively used to increase the wiring density of the first fiber ribbons.
In these cases, a total number of channels arranged in a direction crossing the main surface in the optical path conversion component may be equal to a total number of channels forming each of the at least one channel group in the direction crossing the main surface. As a result, all the channels arranged in the direction crossing the main surface of the circuit board are connected to any of the first fiber ribbons, and there is no surplus in the channels. Therefore, it is possible to improve the space utilization efficiency of the optical path conversion component to contribute to the miniaturization of the optical path conversion component.
In the circuit board with an optical path conversion component described above, plurality of optical fibers forming at least one first fiber ribbon among the one or more first fiber ribbons include at least one stress-applied type polarization maintaining fiber. Then, a fast axis of the polarization maintaining fiber may be along an arrangement direction of the plurality of optical fibers forming the at least one first fiber ribbon including the polarization maintaining fiber. In this case, since the thickness direction of the first fiber ribbon crosses the fast axis of the polarization maintaining fiber, the polarization maintaining fiber is bent mainly in a direction crossing the fast axis. Therefore, since the birefringence increases in a state in which the polarization maintaining fiber is bent, it is possible to suppress the increase in polarization crosstalk.
In the circuit board with an optical path conversion component described above, a first multi-fiber optical connector may be attached to the second end of at least one first fiber ribbon among the one or more first fiber ribbons. In this case, the first fiber ribbon and another fiber ribbon can be easily connected to each other.
The circuit board with an optical path conversion component may further include a harness in which a plurality of second fiber ribbons each having a first end and a second end are bundled. Then, a second multi-fiber optical connector may be attached to the first end of at least one second fiber ribbon among the plurality of second fiber ribbons, and the second multi-fiber optical connector may be connected to the first multi-fiber optical connector. By providing such a harness on the circuit board with an optical path conversion component, a complicated optical connection structure can be easily assembled on the circuit board.
The circuit board with an optical path conversion component may include a harness in which the at least one first fiber ribbon having the first multi-fiber optical connector and one or more third fiber ribbons are bundled. By providing such a harness on the circuit board with an optical path conversion component, a complicated optical connection structure can be easily assembled on the circuit board.
A wiring module for mounting on a circuit board according to one aspect includes an optical path conversion component and one or more first fiber ribbons. The optical path conversion component has a bottom surface, and is configured to be mounted on a main surface of a circuit board. Each of the one or more first fiber ribbons has a first end and a second end, and includes a plurality of optical fibers optically coupled to the optical path conversion component at the first end. The optical path conversion component has at least one channel group for each of the one or more first fiber ribbons and the at least one channel group includes a plurality of channels optically coupled respectively to the plurality of optical fibers. The plurality of channels are arranged in a direction crossing the bottom surface for each of the at least one channel group.
In the wiring module for mounting on a circuit board, the first fiber ribbon is arranged so that the thickness direction crosses the normal of the main surface of the circuit board. Therefore, the first fiber ribbon can be easily bent in a direction parallel to the board surface (the main surface) of the circuit board. As a result, the restrictions on the design of the circuit board can be reduced, and the increase in transmission loss can be suppressed.
In the wiring module for mounting on a circuit board described above, the optical path conversion component may have first optical paths extending from the plurality of channels in parallel with an optical axis of the respective optical fibers, second optical paths extending in a direction crossing the bottom surface, and an optical path converting portion for connecting the first and second optical paths to each other. In this case, the optical device facing the bottom surface of the optical path conversion component can be efficiently coupled to the plurality of optical fibers. In this case, the optical path converting portion may comprise at least one light reflecting surface.
In the wiring module for mounting on a circuit board described above, the at least one channel group may include at least two channel groups arranged in a direction along the bottom surface. In this case, since the plurality of first fiber ribbons are arranged so as to overlap each other in the thickness direction, the wiring density of the first fiber ribbons can be increased. In addition, when a multi-fiber optical connector is attached to the second end of the one or more first fiber ribbons, the first fiber ribbons are easily bent in the arrangement direction. Therefore, regardless of the size of the multi-fiber optical connector, a plurality of channel groups of the optical path conversion component can be densely arranged. This can contribute to the miniaturization of the optical path conversion component.
In the wiring module for mounting on a circuit board described above, plurality of optical fibers forming at least one first fiber ribbon among the one or more first fiber ribbons include at least one a stress-applied type polarization maintaining fiber. Then, a fast axis of the polarization maintaining fiber may be along an arrangement direction of the plurality of optical fibers forming the at least one first fiber ribbon including the polarization maintaining fiber. In this case, since the thickness direction of the first fiber ribbon crosses the fast axis of the polarization maintaining fiber, the polarization maintaining fiber is bent mainly in a direction crossing the fast axis. Therefore, since the birefringence increases in a state in which the polarization maintaining fiber is bent, it is possible to suppress the increase in polarization crosstalk.
Circuit board with an optical path conversion component and a wiring module for mounting on a circuit board according to embodiments of the present disclosure will be described below with reference to the drawings. The present invention is not limited to these examples. The present invention is indicated by the claims, and it is intended to include all the changes within meaning and a range equivalent to the claims. In the following description, the same elements are denoted by the same reference numerals in the description of the drawings, and the repeated description thereof will be omitted.
The wiring module 10A includes an optical path conversion component 11 and one or more (five in the illustrated example) fiber ribbons 12. The optical path conversion component 11 is mounted on the main surface 21 of the circuit board 20 and connected to the circuit board 20. Specifically, the optical path conversion component 11 has an optical fiber connection surface 111 and a bottom surface 115. The normal direction of the optical fiber connection surface 111 and the normal direction of the bottom surface 115 cross each other. The optical fiber connection surface 111 extends in a direction crossing the main surface 21. The bottom surface 115 faces the main surface 21 and is parallel to the main surface 21. In the illustrated example, the bottom surface 115 faces the surface 24 of the optical device 22 and is optically coupled to a plurality of optical ports provided on the surface 24.
The one or more fiber ribbons 12 include a plurality of optical fibers. The one or more fiber ribbons 12 have a first end 12a and a second end opposite to the first end 12a. The plurality of optical fibers are optically coupled to the optical path conversion component 11 at the first end 12a. The fiber ribbon 12 is an example of a first fiber ribbon in the present disclosure.
In the present embodiment, one or more fiber ribbons 12 extend from the optical fiber connection surface 111 of the optical path conversion component 11 along a direction D3 in a state in which the thickness direction d2 of each fiber ribbon 12 crosses the normal direction common to the main surface 21 and the bottom surface 115, in other words, the width direction d1 of each fiber ribbon 12 crosses the main surface 21 and the bottom surface 115. The direction D3 is a direction crossing the normal common to the main surface 21 and the bottom surface 115. The direction D3 may be parallel to the main surface 21 and the bottom surface 115 or may be inclined with respect to the main surface 21 and the bottom surface 115, and it is realistic that the direction D3 is inclined within 30°. In one example, the direction D3 is approximately perpendicular to the normal direction common to the main surface 21 and the bottom surface 115. As shown in
The plurality of optical paths L2 extend from a plurality of optical ports provided on the surface 24 of the optical device 22 along a direction (direction D1 in the illustrated example) crossing the main surface 21 and the bottom surface 115. The optical paths L2 reach the optical path converting portion 114 from the bottom surface 115. The optical path converting portion 114 connects the optical paths L1 and L2 to each other. For example, the optical path converting portion 114 comprises a light reflecting surface. The optical path converting portion 114 changes the direction of light propagating through the optical path L1 to guide the light to the optical path L2, and changes the direction of light propagating through the optical path L2 to guide the light to the optical path L1. In this case, the light reflecting surface is provided along a plane that is inclined with respect to both the extending directions of the optical paths L1 and L2. With such a configuration, the optical path conversion component 11 optically couples each of the plurality of optical ports of the optical device 22 and each of the plurality of optical fibers 13.
The effects obtained by the mounting circuit board 1A and the wiring module 10A of the present embodiment having the above configurations will be described.
In view of such a problem, in the mounting circuit board 1A and the wiring module 10A of the present embodiment, a plurality of channels 112 optically coupled to the plurality of optical fibers 13 forming the fiber ribbon 12 are arranged along the direction D1 crossing the main surface 21 of the circuit board 20 and the bottom surface 115 of the optical path conversion component 11. In this case, the fiber ribbon 12 extends from the optical path conversion component 11 in a direction crossing the normal of the main surface 21 of the circuit board 20 in such a manner that the thickness direction d2 crosses the normal of the main surface 21. Therefore, the fiber ribbon 12 can be easily bent in a direction parallel to the main surface 21 of the circuit board 20. As a result, the restrictions on the design of the circuit board 20 can be reduced, and the increase in transmission loss due to torsional stress or the like can be suppressed.
As in the present embodiment, the optical path conversion component 11 has the optical path L1, the optical path L2, and the optical path converting portion 114, and may optically couple the optical device 22 to the plurality of optical fibers 13. The optical path L1 extends from the plurality of channels 112 in parallel with the optical axis of the optical fiber 13. The optical path L2 extends from the optical device 22 provided on the main surface 21 in a direction crossing the main surface 21. The optical path converting portion 114 connects the optical paths L1 and L2 to each other. In this case, the optical device 22 on the circuit board 20 facing the bottom surface 115 of the optical path conversion component 11 can be efficiently coupled to the plurality of optical fibers 13.
As in the present embodiment, the optical path conversion component 11 may have a plurality of channel groups 113, and at least two channel groups 113 may be arranged in the direction D2 along the main surface 21 and the bottom surface 115. In this case, since the plurality of fiber ribbons 12 are arranged so as to overlap each other in the thickness direction d2, the wiring density of the fiber ribbons 12 can be increased.
As in the first modification example, the multi-fiber optical connector 14 may be attached to the second end 12b of at least one fiber ribbon 12. In this case, the fiber ribbon 12 and another fiber ribbon can be easily connected to each other.
Here,
Generally, the multi-fiber optical connector 14 has a certain width and thickness around the fiber ribbon 12. In addition, as described with reference to
On the other hand, in the first modification example, the plurality of fiber ribbons 12 are arranged in such a manner that the thickness direction d2 crosses the normal of the main surface 21. As a result, as shown in
In the second modification example, the relative angle of the optical fiber 13A with respect to the fiber ribbon 12A is adjusted so that the fast axis A2 of the optical fiber 13A extends along the arrangement direction d1 of the plurality of optical fibers 13 forming the fiber ribbon 12A. In one example, the fast axis A2 of the optical fiber 13A is made to match the arrangement direction d1 of the plurality of optical fibers 13. Alternatively, the fast axis A2 of the optical fiber 13A may form an angle of manufacturing error, for example, about ±10° with respect to the arrangement direction d1 of the plurality of optical fibers 13.
Here,
On the other hand, according to the second modification example, since the thickness direction d2 of the fiber ribbon 12A crosses the fast axis A2 of the optical fiber 13A, the optical fiber 13A is bent mainly in the direction crossing the fast axis A2. In this case, since the birefringence increases when the optical fiber 13A is bent, it is possible to suppress the increase in polarization crosstalk.
In addition, the total number of channels 112 arranged along the direction D1 in the optical path conversion component 11A is equal to the total number of channels 112 forming at least one channel group 113 in the direction D1. In other words, in the plurality of channels 112 arranged along the direction D1, there is no channel 112 that does not consist the channel group 113. For example, in the illustrated example, two channel groups 113 each consisting of eight channels 112 are provided side by side in the direction D1. Therefore, the total number of channels 112 forming the channel group 113 in the direction D1 is 16. On the other hand, the total number of channels 112 arranged along the direction D1 in the optical path conversion component 11A is also 16. In particular, when the number of optical fibers 13 included in each fiber ribbon 12 is the same in the plurality of fiber ribbons 12, the total number of channels 112 arranged along the direction D1 in the optical path conversion component 11A may be an integral multiple of the number of optical fibers 13 of each fiber ribbon 12.
As a comparative example,
On the other hand, in the third modification example shown in
The wiring module 10C includes an optical path conversion component 11C and one or more (five in the illustrated example) fiber ribbons 12. The optical path conversion component 11C is mounted on the main surface 21 of the circuit board 20 and connected to the circuit board 20. Specifically, the optical path conversion component 11C has an optical fiber connection surface 111, an optical device connection surface 118, and a bottom surface 115. The bottom surface 115 faces a region of the main surface 21 adjacent to the mounting region of the optical device 25 and is fixed to the region. The normal direction of the optical device connection surface 118 and the normal direction of the bottom surface 115 cross each other. The optical device connection surface 118 faces the side surface 27 of the optical device 25 and is optically coupled to a plurality of optical ports provided on the side surface 27. In one example, the optical fiber connection surface 111 and the optical device connection surface 118 face opposite to each other. The optical fiber connection surface 111 and the optical device connection surface 118 may be parallel to each other.
The plurality of optical paths L3 extend from a plurality of optical ports provided on the side surface 27 of the optical device 25 along the main surface 21 and the bottom surface 115. The optical paths L3 reach the optical path converting portion 117 from the optical device connection surface 118. The optical path converting portions 116 and 117 connect the optical paths L1 and L3 to each other. For example, each of the optical path converting portions 116 and 117 comprises a light reflecting surface. The light propagating from the optical fiber connection surface 111 through the optical path L1 is changed in direction by the optical path converting portion 116 and is then changed in direction again by the optical path converting portion 117 to be guided to the optical path L3. The light propagating from the optical device connection surface 118 through the optical path L3 is changed in direction by the optical path converting portion 117 and is then changed in direction again by the optical path converting portion 116 to be guided to the optical path L1. In this case, the light reflecting surfaces of the optical path converting portions 116 and 117 are provided along a plane that is inclined with respect to both the extending directions of the optical paths L1 and L3. With such a configuration, the optical path conversion component 11C optically couples each of the plurality of optical ports of the optical device 25 to each of the plurality of optical fibers 13.
As in the fourth modification example, the optical path conversion component 11C may have the optical path converting portions 116 and 117 that connect the optical path L1 and the optical path L3 to each other and optically couple the optical device 25 to the plurality of optical fibers 13. The optical path L1 extends from the plurality of channels 112 in parallel with the optical axis of the optical fiber 13. The optical path L3 extends from the optical device 25 in parallel with the main surface 21. Even in such a case, the optical device 25 on the circuit board 20 can be efficiently coupled to the plurality of optical fibers 13. It is not always necessary to provide two optical path converting portions. For example, instead of the light reflecting surface, a curved waveguide may be provided. In this case, the number of optical path converting portions can be reduced.
The harness 30 includes a plurality of fiber ribbons 32 (second fiber ribbons). Each fiber ribbon 32 has a first end 32a and a second end 32b. Portions of the plurality of fiber ribbons 32 excluding the first end 32a and the second end 32b are collectively bundled by a tube 31. In the illustrated example, the first ends 32a of all the fiber ribbons 32 extend from a first end 31a of the tube 31 to the outside of the tube 31. Without being limited to the illustrated example, the first ends 32a of some fiber ribbons 32 among the plurality of fiber ribbons 32 may extend from the first end 31a of the tube 31 to the outside of the tube 31. Then, the first ends 32a of the other fiber ribbons 32 may extend from the side surface of the tube 31 between the first end 31a and the second end 31b to the outside of the tube 31. In the illustrated example, the second ends 32b of some fiber ribbons 32 among the plurality of fiber ribbons 32 extend from the second end 31b of the tube 31 to the outside of the tube 31. The second ends 32b of the other fiber ribbons 32 extend from the side surface of the tube 31 between the first end 31a and the second end 31b to the outside of the tube 31. Without being limited to the illustrated example, the second ends 32b of all the fiber ribbons 32 may extend from the second end 31b of the tube 31 to the outside of the tube 31.
A so-called gang connector 33A, which can be collectively connected to the plurality of multi-fiber optical connectors 14 shown in
A complicated optical connection structure can be easily assembled on the circuit board 20 by connecting the gang connector 33A (when there are a plurality of gang connectors 33A, at least one of the gang connectors 33A) of the harness 30 having such a configuration to a plurality of multi-fiber optical connectors 14. Instead of the gang connector 33A, a multi-fiber optical connector corresponding to each of the plurality of multi-fiber optical connectors 14 may be attached to the first end 32a of the fiber ribbon 32. Instead of at least one of the plurality of multi-fiber optical connectors 33C attached to the second ends 32b of the plurality of fiber ribbons 32, the gang connector 33A or the low mating force connector 33B may be attached. Instead of the low mating force connector 33B and the multi-fiber optical connector 33C, an optical path conversion component different from the optical path conversion component 11, another optical fiber connection device such as an optical fiber array, or an optical device different from the optical devices 22 and 25 may be optically coupled to the fiber ribbon 32.
The optical path conversion component 11 of the present embodiment is optically coupled to the first end 12a of the fiber ribbon 12. The multi-fiber optical connector 14 is attached to the second end 12b of the fiber ribbon 12. A multi-fiber optical connector 43 is attached to the first end 42a and the second end 42b of the fiber ribbon 42.
By providing the harness 40 on the mounting circuit board as in the sixth modification example, a complicated optical connection structure can be easily assembled on the circuit board 20. Instead of the optical path conversion component 11 of the embodiment described above, the optical path conversion component 11A according to the third modification example (see
The circuit board with an optical path conversion component and the wiring module for mounting on a circuit board according to the present disclosure are not limited to the above-described embodiment and each modification example, and various modifications can be made. For example, in the present embodiment, the first optical path and the second optical path are optically coupled to each other through an optical path converting portion. The first optical path and the second optical path may be optically coupled to each other through a bent optical fiber. The optical fiber is optically coupled to the first optical path on the optical fiber connection surface that is one surface of the optical path conversion component, but may be optically coupled inside the optical path conversion component. In the present embodiment and each modification example, the configuration of the present disclosure is applied to the fiber ribbon in which optical fibers are arranged in a row. The configuration of the present disclosure can also be applied to a fiber ribbon in which optical fibers are arranged in two or more rows. In this case, the plurality of channels of the optical path conversion component may be arranged for each channel group with the direction crossing the main surface as a main arrangement direction, that is, a direction in which a large number of channels are arranged. In the present embodiment and each modification example, the first optical path and the optical axis direction of the optical fiber extend in parallel with each other. Even if there is an inclination between the first optical path and the optical axis direction of the optical fiber because the end face of the optical fiber is not perpendicular to the optical fiber axis due to manufacturing error or the like or because the refractive indices of the optical path conversion component and the optical fiber are different, the configuration of the present disclosure can be applied as long as the first optical path is optically coupled to the optical fiber.
| Number | Date | Country | Kind |
|---|---|---|---|
| 2020-073428 | Apr 2020 | JP | national |
| Filing Document | Filing Date | Country | Kind |
|---|---|---|---|
| PCT/JP2021/015156 | 4/12/2021 | WO |
