Optical connector, optical coupling structure, and method for manufacturing optical connector

Abstract

An optical connector (1) according to the present disclosure is provided with: a ferrule (20) having a front end (21) and a rear end (22) facing each other in one direction, a sheath insertion hole (24) formed in the rear end (22), and a plurality of optical fiber holding holes (25) extending from the sheath insertion hole (24) toward the front end; a sheath (30) having a through hole (31) penetrating in one direction, the sheath (30) being inserted into the sheath insertion hole (24) from the rear end (22); and a plurality of optical fibers (10) each having at least one of a core and a stress imparting portion at a position offset from the respective central axis, the plurality of optical fibers (10) being inserted into the through hole (31) in one direction and being held in the plurality of optical fiber holding holes (25), respectively. An adhesive (A) for fixing the plurality of optical fibers (10) to the ferrule (20) is provided inside the ferrule (20) between the sheath (30) and the tip (21). The sheath (30) is provided with a sealing member (35) that is disposed so as to block a gap between the inner surface of the through-hole (31) and the plurality of optical fibers (10) when viewed in one direction.

Description

Technical Field

[0001] The present disclosure relates to an optical connector, an optical coupling structure and a method for manufacturing the optical connector.

[0002] This application claims the priority based on Japanese application No. 2022-123798 filed on August 3, 2022, and cites all the contents described in the said Japanese application. Background Art

[0003] Patent document 1 discloses an optical connector in which a plurality of optical fibers are inserted into the interior of a ferrule via a sheath. The sheath is a cylindrical body having a through hole for a plurality of optical fibers to pass through. The sheath is used to protect a plurality of optical fibers. The plurality of optical fibers are inserted into the interior of the ferrule through the through hole of the sheath. The plurality of optical fibers are fixed to the ferrule by an adhesive injected into the interior of the ferrule.

[0004] Prior art literature

[0005] Patent Literature

[0006] Patent Document 1: Japanese Patent Application Publication No. 2020-101613 Summary of the invention

[0007] An optical connector according to one embodiment of the present disclosure comprises: a ferrule having a front end and a rear end facing each other in one direction, and having a sheath insertion hole formed at the rear end and a plurality of optical fiber holding holes extending from the sheath insertion hole toward the front end; a sheath having a through hole penetrating in one direction, the sheath being inserted into the sheath insertion hole from the rear end; and a plurality of optical fibers, each having at least one of a core and a stress imparting portion at a position deviated from the respective central axis, the plurality of optical fibers being inserted into the through hole in one direction and being respectively held in the plurality of optical fiber holding holes. An adhesive for fixing the plurality of optical fibers to the ferrule is provided inside the ferrule between the sheath and the front end. A sealing member is provided in the sheath, the sealing member being configured to block a gap between the inner surface of the through hole and the plurality of optical fibers when viewed in one direction. BRIEF DESCRIPTION OF THE DRAWINGS

[0008] Figure 1 It is a perspective view of the optical connector according to the first embodiment.

[0009] Figure 2 yes Figure 1 A cross-sectional view of an optical connector.

[0010] Figure 3 It is along Figure 2 A cross-sectional view of a III-III line optical connector.

[0011] Figure 4 Yes Figure 1A three-dimensional diagram of the optical coupling structure of an optical connector.

[0012] Figure 5 Yes means Figure 1 A top view of the manufacturing process of an optical connector.

[0013] Figure 6 Yes means Figure 5 A top view of the subsequent manufacturing process.

[0014] Figure 7 Yes means Figure 6 A cross-sectional view of a subsequent manufacturing process.

[0015] Figure 8 Yes means Figure 7 A cross-sectional view of a subsequent manufacturing process.

[0016] Fig. 9 It is a cross-sectional view of an optical connector of a comparative example.

[0017] Fig.10 It is along Fig. 9 A cross-sectional view of the X-line optical connector.

[0018] Fig.11 It is a cross-sectional view of the optical connector according to the second embodiment.

[0019] Fig.12 It is along Fig.11 A cross-sectional view of the optical connector of the XII-XII line.

[0020] Fig.13 Yes means Fig.11 A top view of the manufacturing process of an optical connector.

[0021] Fig.14 Yes means Fig.13 A cross-sectional view of a subsequent manufacturing process.

[0022] Fig.15 Yes means Fig.14 A cross-sectional view of a subsequent manufacturing process.

[0023] Fig.16 Yes means Fig.15 A cross-sectional view of a subsequent manufacturing process.

[0024] Fig.17 It is a cross-sectional view of an optical connector according to a modified example of the first embodiment.

[0025] Fig.18 yes Fig.17 A perspective view of an optical fiber holding component included in an optical connector.

[0026] Fig.19It is a cross-sectional view of an optical connector according to another modified example of the first embodiment.

[0027] Fig. 20 yes Fig.19 A perspective view of an optical fiber holding component included in an optical connector.

[0028] Fig.21 It is a cross-sectional view of an optical connector according to another modified example of the first embodiment.

[0029] Fig. 22 yes Fig.21 A perspective view of an optical fiber holding component included in an optical connector.

[0030] Fig.23 It is a cross-sectional view showing a modified example of the optical fiber holding member.

[0031] Fig.24 It is a cross-sectional view showing another modified example of the optical fiber holding member.

[0032] Fig.25 It is a cross-sectional view of an optical connector according to a modified example of the second embodiment. DETAILED DESCRIPTION

[0033] [Problems to be Solved by the Present Disclosure]

[0034] In the case of installing a plurality of optical fibers that need to be rotationally aligned on the ferrule described in Patent Document 1, after the plurality of optical fibers are rotationally aligned in a spread state, each optical fiber is inserted into the interior of the ferrule through the through hole of the sheath, and fixed to the ferrule by an adhesive injected into the interior of the ferrule. If the plurality of optical fibers are inserted into the through hole of the sheath in a spread state in this way, the optical fibers are likely to overlap with each other. If such an overlap of the optical fibers occurs, the adhesive injected into the interior of the ferrule is likely to leak out of the ferrule along the optical fibers. If the adhesive leaked to the outside is solidified while being attached to the optical fibers, the flexibility of the optical fibers will be lost, and the bending resistance of the optical fibers may be reduced.

[0035] [Effects of the present disclosure]

[0036] According to the optical connector, the optical coupling structure, and the method for manufacturing the optical connector disclosed herein, it is possible to suppress a decrease in the bending resistance of the optical fiber.

[0037] [Description of Embodiments of the Present Disclosure]

[0038] First, the contents of the embodiments of the present disclosure will be listed and described.

[0039] (1) An optical connector according to one embodiment of the present disclosure comprises: a ferrule having a front end and a rear end facing each other in one direction, and having a sheath insertion hole formed at the rear end and a plurality of optical fiber holding holes extending from the sheath insertion hole toward the front end; a sheath having a through hole extending in one direction, the sheath being inserted into the sheath insertion hole from the rear end; and a plurality of optical fibers each having at least one of a core and a stress imparting portion at a position offset relative to their respective central axes, the plurality of optical fibers being inserted into the through holes in one direction and being respectively held in the plurality of optical fiber holding holes. An adhesive for fixing the plurality of optical fibers to the ferrule is provided inside the ferrule between the sheath and the front end. A sealing member is provided in the sheath, the sealing member being configured to block a gap between the inner surface of the through hole and the plurality of optical fibers when viewed in one direction.

[0040] In the optical connector, a plurality of optical fibers are inserted into the through hole of the sheath and are respectively held in the plurality of optical fiber holding holes of the ferrule, wherein the sheath is inserted into the sheath insertion hole of the ferrule. A sealing member is provided in the sheath, and the sealing member is configured to block the gap between the inner surface of the through hole and the plurality of optical fibers when viewed in one direction. Therefore, when the adhesive is injected into the inside of the ferrule between the sheath and the front end of the ferrule, the adhesive can be prevented from leaking out of the ferrule through the gap between the inner surface of the through hole and the plurality of optical fibers. If a structure with such a sealing member is adopted, even in the case where the optical fibers overlap each other, the sealing member can be used to prevent the adhesive from flowing out of the ferrule. Thus, the adhesive leaking out of the ferrule can be prevented from solidifying while being attached to the optical fiber. As a result, the reduction in the bending resistance of the optical fiber caused by the solidification of the leaked adhesive can be suppressed.

[0041] (2) In the optical connector described in (1) above, the sealing member may be arranged inside the through hole and may cover a plurality of optical fibers. In this case, the plurality of optical fibers are inserted into the through hole while being covered by the sealing member, so that the sealing member can be arranged to block the gap between the inner surface of the through hole and the plurality of optical fibers. If the plurality of optical fibers are covered by the sealing member before being inserted into the through hole, the plurality of optical fibers can be inserted into the through hole in a concentrated manner after being rotationally aligned and arranged. In this case, the insertion of the plurality of optical fibers into the ferrule can be performed more easily than in a case where the plurality of optical fibers are inserted into the through hole after being spread out into a single core for rotational alignment.

[0042] (3) In the optical connector described in (1) above, the sealing member may be provided on the rear surface of the sheath facing the side opposite to the plurality of optical fiber holding holes in one direction, and may block the opening of the through hole formed on the rear surface. In this case, after the plurality of optical fibers are inserted into the through holes of the sheath, a simple operation of applying the material of the sealing member in a manner blocking the opening of the rear surface of the sheath is performed, so that the sealing member that blocks the gap between the inner surface of the through hole and the plurality of optical fibers can be easily formed.

[0043] (4) In the optical connector described in any one of (1) to (3) above, the sealing member may be made of a material different from that of the adhesive. A relatively hard material is suitable as the material of the adhesive to fix the plurality of optical fibers to the ferrule. On the other hand, a relatively soft material is suitable as the material of the sealing member provided in the sheath to ensure the bending resistance of the optical fiber. Therefore, taking into account the differences in their respective uses, a material different from that of the adhesive is used as the material of the sealing member, thereby enabling the selection of a material suitable for the type of the sealing member.

[0044] (5) In the optical connector described in any one of (1) to (4) above, each of the plurality of optical fibers may have a coating covered by a coating. The coatings of the plurality of optical fibers may extend in one direction to the outside of the ferrule on the side opposite to the inside of the ferrule relative to the sealing member, and may be covered by a resin layer on the outside. By covering the coatings of the plurality of optical fibers extending to the outside with a resin layer, the coatings of the plurality of optical fibers exposed to the outside can be protected from external forces.

[0045] (6) The optical connector described in any one of (1) to (5) above may further include: an optical fiber holding component disposed between the plurality of optical fiber holding holes and the sheath inside the ferrule and holding the plurality of optical fibers. If such an optical fiber holding component is disposed inside the ferrule, the insertion of the plurality of optical fibers into the ferrule becomes easier.

[0046] (7) In the optical connector described in (6) above, the plurality of optical fibers may each have a coating covered by a coating. Alternatively, the optical fiber holding member may be a resin layer covering the coatings of the plurality of optical fibers. In this case, the coatings of the plurality of optical fibers are covered by the resin layer, thereby ensuring the bending resistance of each optical fiber.

[0047] (8) In the optical connector described in (6) above, each of the plurality of optical fibers may have a coating removal portion obtained by removing a predetermined length of coating from the top end surface. Alternatively, the optical fiber holding member may be a resin layer covering the coating removal portions of the plurality of optical fibers. In this case, the coating removal portions of the plurality of optical fibers are covered by the resin layer, thereby ensuring the bending resistance of each optical fiber.

[0048] (9) In the optical connector described in (6) above, the optical fiber holding component may have a plurality of V-grooves extending in one direction. Alternatively, the plurality of optical fibers may be accommodated in the plurality of V-grooves. In this case, by accommodating the plurality of optical fibers in the plurality of V-grooves of the optical fiber holding component, the positions and rotation angles of the plurality of optical fibers relative to the ferrule can be precisely determined.

[0049] (10) In the optical connector described in (6) above, the optical fiber holding component may have a plurality of optical fiber through holes extending in one direction. Alternatively, a plurality of optical fibers may be inserted into the plurality of optical fiber through holes. In this case, by inserting the plurality of optical fibers into the plurality of optical fiber through holes of the optical fiber holding component, the position and rotation angle of the plurality of optical fibers relative to the ferrule can be precisely determined.

[0050] (11) In the optical connector described in any one of (1) to (10) above, the optical fiber may be any one of a multi-core optical fiber, a polarization-maintaining optical fiber, and a bundled optical fiber. When using such an optical fiber that requires rotational core alignment, it is easy for the optical fibers to overlap with each other. In contrast, in the above-mentioned optical connector, even when the optical fibers overlap with each other, it is possible to suppress the adhesive from leaking out of the ferrule. Thus, it is possible to suppress the reduction in the bending resistance of the optical fiber due to the solidification of the leaked adhesive.

[0051] (12) An optical coupling structure of one embodiment of the present disclosure includes a first optical connector and a second optical connector as the optical connectors described in any one of (1) to (11) above. The first optical connector is arranged to be opposite to the second optical connector in one direction and optically coupled to the second optical connector. The optical coupling structure includes the first optical connector and the second optical connector as the optical connectors described above, and thus, as described above, it is possible to suppress a decrease in the bending resistance of the optical fiber.

[0052] (13) A method for manufacturing an optical connector according to one embodiment of the present disclosure comprises the following steps: preparing a ferrule, a sheath, and a plurality of optical fibers, wherein the ferrule has a front end and a rear end opposite to each other in one direction, and has a sheath insertion hole formed at the rear end and a plurality of optical fiber retaining holes extending from the sheath insertion hole toward the front end, the sheath has a through hole penetrating in one direction and is inserted into the sheath insertion hole from the rear end, and the plurality of optical fibers respectively have at least one of a core and a stress imparting portion at a position deviated from their respective center axes; inserting the plurality of optical fibers into the interior of the ferrule in such a manner that the plurality of optical fibers are inserted into the through holes and are respectively retained in the plurality of optical fiber retaining holes; forming a sealing member configured to block a gap between an inner surface of the through hole and the plurality of optical fibers when viewed in one direction; and injecting an adhesive for fixing the plurality of optical fibers to the ferrule into the interior of the ferrule between the sheath and the front end, thereby fixing the plurality of optical fibers to the ferrule. According to the manufacturing method of the optical connector, the sealing member can prevent the adhesive from flowing out of the ferrule, thereby preventing the adhesive leaking out of the ferrule from solidifying while being attached to the optical fiber. As a result, the reduction in the bending resistance of the optical fiber due to the solidification of the leaked adhesive can be prevented.

[0053] (14) In the manufacturing method of the optical connector described in (13) above, the step of inserting the plurality of optical fibers into the interior of the ferrule may be performed after the step of forming the sealing member and before the step of fixing the plurality of optical fibers to the ferrule, and in the step of forming the sealing member, a sealing member covering the plurality of optical fibers is formed, and in the step of inserting the plurality of optical fibers into the interior of the ferrule, the sealing member is arranged inside the through-hole when the plurality of optical fibers are inserted into the through-hole. If the plurality of optical fibers are covered by the sealing member before being inserted into the through-hole, the plurality of optical fibers can be inserted into the through-hole in an arranged state, thereby facilitating the insertion of the plurality of optical fibers into the ferrule compared to the case where the plurality of optical fibers are inserted into the through-hole in a state where they are spread out into single cores for rotational alignment.

[0054] (15) In the manufacturing method of the optical connector described in (13) above, the step of forming the sealing member may be performed after the step of inserting the plurality of optical fibers into the ferrule and before the step of fixing the plurality of optical fibers to the ferrule, and in the step of forming the sealing member, after the plurality of optical fibers are inserted into the through-hole, the sealing member is formed on the rear surface of the sheath facing in one direction opposite to the plurality of optical fiber holding holes so as to block the opening of the through-hole formed on the rear surface. In this case, the sealing member that blocks the opening of the through-hole can be easily formed by performing a simple operation of applying the material of the sealing member so as to block the opening of the rear surface of the sheath after the plurality of optical fibers are inserted into the through-hole of the sheath.

[0055] [Details of the embodiments of the present disclosure]

[0056] Hereinafter, specific examples of the optical connector, optical coupling structure, and method for manufacturing the optical connector according to the embodiments of the present disclosure are described with reference to the accompanying drawings. The present disclosure is not limited to these examples, but is shown by the claims, and is intended to include all changes within the meaning and scope equivalent to the claims. In the following description, in the description of the drawings, the same reference numerals are marked on the same elements, and repeated descriptions are appropriately omitted.

[0057] [First embodiment]

[0058] Figure 1 It is a perspective view of the optical connector 1 according to the first embodiment. Figure 2 is a cross-sectional view of the optical connector 1 . Figure 3 It is along Figure 2 A cross-sectional view of the optical connector 1 taken along line III-III of FIG. In the following description, for ease of explanation, the long dimension of the optical connector 1 is set to the X direction (an example of "one direction"), the short dimension of the optical connector 1 is set to the Y direction, and the height direction of the optical connector 1 is set to the Z direction. The X direction, the Y direction, and the Z direction intersect with each other (in one example, they are orthogonal). In the following description, one side of the Z direction is sometimes referred to as "upper", the other side of the Z direction is sometimes referred to as "lower", one side of the X direction is sometimes referred to as "front", and the other side of the X direction is sometimes referred to as "rear".

[0059] like Figure 1 , Figure 2 as well as Figure 3 As shown, the optical connector 1 includes, for example, a ribbon optical fiber T, a ferrule 20, and a sheath 30. The ribbon optical fiber T includes a plurality of optical fibers 10 extending in the X direction and arranged side by side in the Y direction. The plurality of optical fibers 10 are cables for transmitting optical signals. In this embodiment, an example is given in which twelve optical fibers 10 are arranged side by side in a row in the Y direction. However, the number of the plurality of optical fibers 10 is not limited to twelve, and may be, for example, four, eight, twenty-four, or other numbers. The plurality of optical fibers 10 may also be arranged side by side in two or more rows.

[0060] like Figure 2 As shown in FIG. 1 , each optical fiber 10 has a top end face 11, a coating removal portion 12, and a coating portion 13. The top end face 11 is the end face of the top end of the optical fiber 10 located in the X direction. The coating removal portion 12 is a portion of the optical fiber 10 where a predetermined length of the resin coating 15 (an example of a “coating”, see FIG. 1 ) is removed from the top end face 11. Figure 3 ). The coating portion 13 is a portion of the optical fiber 10 where the resin coating 15 remains. The coating portion 13 is provided on the side opposite to the top end face 11 across the coating removal portion 12. In the coating removal portion 12, the cladding 16 (see Figure 3 In the coating portion 13 , the cladding 16 of the optical fiber 10 is covered with the resin coating 15 .

[0061] The optical fiber 10 is an optical fiber that needs to be rotated and aligned with respect to the central axis L. In this embodiment, a multi-core optical fiber (MCF: Multi Core Fiber) is exemplified as the optical fiber 10 that needs to be rotated and aligned. Figure 3 As shown, the optical fiber 10 has a plurality of cores 17 covered by a cladding 16. Figure 3 In the example shown, the two cores 17 are arranged at positions offset from the central axis L. The state in which the cores 17 are offset from the central axis L can be a state in which the centers of the cores 17 do not coincide with the central axis L when viewed in the X direction.

[0062] The number and configuration of the plurality of fiber cores 17 are not limited to Figure 3 The examples shown can be changed appropriately. For example, the number of the plurality of cores 17 is not limited to two, and may be four, six, or eight or more. The plurality of cores 17 may also have a central core arranged on the central axis L. As the optical fiber 10 that needs to be rotationally aligned, in addition to multi-core optical fibers, for example, bundle optical fibers and polarization maintaining fibers (PMF: Polarization Maintaining Fiber) are also cited. In the case where the optical fiber 10 is a polarization maintaining fiber, the optical fiber 10 has a stress-applying portion at a position deviated from the central axis L. In this case, for example, the optical fiber 10 has a core arranged on the central axis L, and a pair of stress-applying portions are arranged on both sides of the core.

[0063] The ferrule 20 is a component for holding the ends of the plurality of optical fibers 10, and is, for example, an MT (Mechanical Transfer) ferrule. The ferrule 20 has a substantially rectangular shape. The ferrule 20 is made of, for example, a resin such as PPS (Polyphenylene Sulfide). The ferrule 20 has, for example, a front end face 21, a rear end face 22, a pair of guide holes 23, 23 (see Figure 1 ), a sheath insertion hole 24 and a plurality of optical fiber holding holes 25.

[0064] The front end face 21 is an end face of the front end of the ferrule 20 located in the X direction. The rear end face 22 is an end face of the rear end of the ferrule 20 located in the X direction. The front end face 21 and the rear end face 22 extend in the Y direction and the Z direction and are arranged side by side in the X direction. A pair of guide holes 23, 23 are opened at both ends of the front end face 21 in the Y direction and extend from the front end face 21 to the rear end face 22 in the X direction (see Figure 1). An opening 22a capable of collectively receiving a plurality of optical fibers 10 is formed on the rear end face 22. That is, the opening 22a can receive the plurality of optical fibers 10 in a state where the plurality of optical fibers 10 are bundled together.

[0065] The sheath insertion hole 24 is a hole for inserting the sheath 30, and extends forward from the opening 22a of the rear end face 22. A wall surface 26 is formed inside the ferrule between the front end face 21 and the rear end face 22, and the sheath insertion hole 24 extends from the opening 22a to the wall surface 26 in the X direction. The wall surface 26 can be set as a plane along the Y direction and the Z direction, for example. The sheath insertion hole 24 is, for example, rectangular when viewed in the X direction. The sheath portions 13 of the plurality of optical fibers 10 are inserted into the sheath insertion hole 24 in the X direction via the sheath 30, that is, the sheath portions 13 of the plurality of optical fibers 10 are inserted into the sheath insertion hole 24 in a state of being gathered into one bundle.

[0066] The plurality of optical fiber holding holes 25 are connected to the jacket insertion hole 24 in the X direction, and the plurality of optical fiber holding holes 25 extend from the jacket insertion hole 24 to the front end face 21 in the X direction. The plurality of optical fiber holding holes 25 penetrate from the wall surface 26 to the front end face 21 in the X direction, and open on the front end face 21. The plurality of optical fiber holding holes 25 are arranged side by side in the Y direction between the pair of guide holes 23, 23 corresponding to the plurality of optical fibers 10. Each of the plurality of optical fiber holding holes 25 is, for example, circular when viewed in the X direction. The inner diameter of each of the plurality of optical fiber holding holes 25 is set to be the same as the outer diameter of the jacket removal portion 12, or slightly larger than the outer diameter of the jacket removal portion 12. The jacket removal portions 12 of the plurality of optical fibers 10 are respectively inserted into and held in the plurality of optical fiber holding holes 25.

[0067] like Figure 2 and Figure 3 As shown, the sheath 30 is a cylindrical member having a through hole 31 through which a plurality of optical fibers 10 pass. The sheath 30 is inserted into the sheath insertion hole 24 from the rear end face 22 in the X direction. The sheath 30 is, for example, rectangular when viewed in the X direction, and fits into the rectangular sheath insertion hole 24 without a gap. The sheath 30 is fixed to the sheath insertion hole 24, and the rear end portion of the sheath 30 protrudes slightly rearward from the rear end face 22.

[0068] The sheath 30 has a front surface 32 and a rear surface 33 arranged side by side in the X direction. The front surface 32 is an end surface located at the front end (one end) of the sheath 30 in the X direction. The rear surface 33 is an end surface located at the rear end (the other end) of the sheath 30 in the X direction. When the sheath 30 is inserted into the sheath insertion hole 24, the front surface 32 is arranged inside the sheath insertion hole 24 and is opposite to the wall surface 26 in which the plurality of optical fiber holding holes 25 are formed in the X direction. The rear surface 33 is arranged outside the sheath insertion hole 24 and is arranged behind the rear end surface 22. The through hole 31 penetrates from the front surface 32 to the rear surface 33 in the X direction. The through hole 31 is, for example, rectangular when viewed in the X direction. The opening 32a and the opening 33a of the through hole 31 are formed on the front surface 32 and the rear surface 33, respectively. The coatings 13 of the plurality of optical fibers 10 are collectively inserted into the through hole 31 in the X direction. That is, the coatings 13 of the plurality of optical fibers 10 are inserted into the through hole 31 in the X direction in a state of being bundled together.

[0069] The sheath 30 is made of an elastic body such as rubber or elastic resin. With this structure, even if bending stress is applied to the plurality of optical fibers 10 inserted into the sheath 30, the sheath 30 absorbs the bending stress, thereby preventing the plurality of optical fibers 10 from being sharply bent. Thus, the bending resistance of the plurality of optical fibers 10 is improved. Moreover, the sheath 30 is fitted into the sheath insertion hole 24 without a gap, thereby preventing the adhesive A injected into the internal space R of the ferrule 20 from leaking to the outside of the ferrule 20. In this way, the sheath 30 has the function of protecting the plurality of optical fibers 10 and the function of preventing the adhesive A from leaking.

[0070] The internal space R is a space formed inside the ferrule 20 between the front end face 21 and the sheath 30. The internal space R can be, for example, a space including the internal space between the front surface 32 and the wall surface 26 in the sheath insertion hole 24 and the internal space of the plurality of optical fiber holding holes 25. A window 28 connected to the internal space R is formed on the upper surface 27 of the ferrule 20. The upper surface 27 is, for example, a plane along the XY plane, and extends in the X direction between the front end face 21 and the rear end face 22. The window 28 is an introduction hole for introducing an adhesive A into the internal space R. The adhesive A is used to fix the plurality of optical fibers 10 to the ferrule 20, and is composed of, for example, a resin material such as a thermosetting resin. The adhesive A is filled in at least the space between the front surface 32 and the wall surface 26 in the internal space R. The adhesive A can also be filled in the interior of the plurality of optical fiber holding holes 25.

[0071] In this embodiment, if Figure 2 and Figure 3As shown, a sealing member 35 is provided inside the through hole 31 of the sheath 30. The sealing member 35 is a resin layer that is provided to cover the coating 13 of the plurality of optical fibers 10 together inside the through hole 31, that is, a resin layer that covers the coating 13 of the plurality of optical fibers 10 in a bundle. The sealing member 35 is provided to prevent the adhesive A injected into the internal space R from leaking out to the outside of the ferrule 20 along the plurality of optical fibers 10 in the through hole 31. The sealing member 35 is in the shape of a rectangular tube that is fitted into the through hole 31 in the X direction. When viewed in the X direction, the size of the sealing member 35 is set to be the same as the size of the through hole 31, for example. It is possible that the sealing member 35 contacts the inner surface of the through hole 31 all over the periphery when viewed in the X direction. The sealing member 35 is configured to block the gap between the inner surface of the through hole 31 and the coating 13 of the plurality of optical fibers 10 when viewed in the X direction.

[0072] The state where the sealing member 35 blocks the gap between the inner surface of the through hole 31 and the covering portion 13 includes: the state where the sealing member 35 is sealed between the inner surface of the through hole 31 and the covering portion 13 without a gap; and the state where the sealing member 35 seals the gap in a liquid-tight manner so that the liquid adhesive A does not flow out of the gap to the outside of the ferrule 20 when injected into the internal space R. In the state where the sealing member 35 seals the gap in a liquid-tight manner, there may be a tiny gap between the inner surface of the through hole 31 and the covering portion 13 that does not allow the liquid adhesive A to flow out of the internal space R to the outside of the ferrule 20.

[0073] In this embodiment, the sealing member 35 is provided throughout the entire internal space of the through hole 31 in the XZ cross section. However, the sealing member 35 may be configured to block the gap between the inner surface and the covering portion 13 when viewed in the X direction, and the sealing member 35 may be provided in a portion of the internal space of the through hole 31 in the XZ cross section. Alternatively, the sealing member 35 may be provided outside the through hole 31 (for example, the front surface 32 or the rear surface 33 of the sheath 30). Figure 2 In the illustrated example, the sealing member 35 is arranged so as to slightly protrude from the through hole 31 to the front and rear in the X direction.

[0074] The sealing member 35 is made of, for example, the same material as the tape resin 18 constituting the tape optical fiber T. The tape resin 18 is a resin layer that covers the coatings 13 of the plurality of optical fibers 10 collectively, that is, a resin layer that covers the coatings 13 of the plurality of optical fibers 10 in a bundled manner in a row. The tape resin 18 is provided at a position further back than the front ends of the coatings 13 of the plurality of optical fibers 10. The tape resin 18 collectively covers the coatings 13 of the plurality of optical fibers 10 extending backward from the through hole 31 to the outside of the ferrule 20, and bundles them in a row. The tape resin 18 integrally holds the coatings 13 of the plurality of optical fibers 10 to suppress positional variation between the plurality of optical fibers. In a state where the plurality of optical fibers 10 are held by the tape resin 18, the plurality of optical fibers 10 in front of the tape resin 18 can be rotated and aligned. In a state where the ends of the optical fibers 10 are inserted into the ferrule 20, the tape resin 18 is arranged at a position that is a predetermined distance away from the rear surface 33 of the sheath 30 to the rear. The sealing member 35 may be in contact with the tape resin 18 in the X direction, or may be separated from the tape resin 18. The sealing member 35 may bundle the coating portions 13 of the plurality of optical fibers 10 in a row, similarly to the tape resin 18.

[0075] For example, an adhesive such as an ultraviolet (UV) curable resin, a thermosetting resin, or an anaerobic resin is used as the material of the tape resin 18. Generally, a soft and flexible material such as a polyurethane resin, a silicone resin, a modified silicone resin, or a rubber resin is used as the material of the tape resin 18 to ensure the resistance of the plurality of optical fibers 10 to bending. On the other hand, a relatively hard material such as an epoxy resin or an acrylic resin is used as the material of the adhesive A to fix the plurality of optical fibers 10 to the ferrule 20. As for the material of the sealing member 35, the same material as the tape resin 18 is used from the viewpoint of ensuring the resistance of the plurality of optical fibers 10 to bending, as with the tape resin 18. As a result, a material different from the adhesive A is used as the material of the sealing member 35, specifically, a material softer than the adhesive A is used as the material of the sealing member 35. The material of the sealing member 35 may be the same material as the adhesive A, or may be another material different from the tape resin 18 and the adhesive A. For example, the material of the sealing member 35 may be a material different from the tape resin 18 among polyurethane resin, silicone resin, modified silicone resin, and rubber resin.

[0076] Figure 4: is a perspective view of an optical coupling structure 100 of the present embodiment. The optical coupling structure 100 includes, for example, a first optical connector 1a, a second optical connector 1b, a pair of guide pins 40, 40, and a spacer 50. The first optical connector 1a and the second optical connector 1b have the same configuration as the optical connector 1 described above. In the optical coupling structure 100, the front end surface 21 of the first optical connector 1a and the front end surface 21 of the second optical connector 1b face each other in the X direction with a gap therebetween. The pair of guide pins 40, 40 are fitted into a pair of guide holes 23, 23 of the first optical connector 1a and a pair of guide holes 23, 23 of the second optical connector 1b. Thus, the positions of the first optical connector 1a and the second optical connector 1b in the YZ plane are defined.

[0077] The spacer 50 is a plate-shaped member having an opening 50a. The spacer 50 is arranged between the front end face 21 of the first optical connector 1a and the front end face 21 of the second optical connector 1b. The opening 50a allows a plurality of optical paths extending between the first optical connector 1a and the second optical connector 1b to pass through. Thus, the first optical connector 1a and the second optical connector 1b are optically coupled. The spacer 50 abuts against the front end face 21 of the first optical connector 1a and the front end face 21 of the second optical connector 1b. Thus, the gap between the first optical connector 1a and the second optical connector 1b in the X direction is defined.

[0078] Next, refer to Figure 5 , Figure 6 , Figure 7 as well as Figure 8 A method for manufacturing the optical connector 1 will be described. Figure 5 It is a plan view showing the manufacturing process of the optical connector 1. Figure 6 Yes means Figure 5 A top view of the subsequent manufacturing process. Figure 7 Yes means Figure 6 A cross-sectional view of a subsequent manufacturing process. Figure 8 Yes means Figure 7 A cross-sectional view of a subsequent manufacturing process.

[0079] First, prepare a plurality of optical fibers 10, ferrules 20, and sheaths 30. Then, Figure 5 As shown in FIG. 1 , in order to rotationally align the plurality of optical fibers 10 included in the optical fiber ribbon T, the plurality of optical fibers 10 in the portion of the optical fiber ribbon T to be inserted into the ferrule 20 are changed from a ribbonized state to a spread-out state of single cores. At this time, the ribbonized resin 18 remains behind the coating 13 of the plurality of optical fibers 10. In this state, the plurality of optical fibers 10 are rotationally aligned around the central axis L.

[0080] Then, if Figure 6As shown in the figure, in a state where the plurality of optical fibers 10 that have been rotationally aligned are arranged in a row in the Y direction, the material of the sealing member 35 is applied so as to cover the coating 13 of the plurality of optical fibers 10 in front of the tape-forming resin 18. In this state, the material of the sealing member 35 is cured, thereby forming the sealing member 35 that integrally holds the coating 13 of the plurality of optical fibers 10. Thus, the plurality of optical fibers 10 that have been spread out into single cores are tape-formed again through the sealing member 35. Therefore, the sealing member 35 can also be said to be a re-tape-forming resin for tape-forming the plurality of optical fibers 10 that have been spread out into single cores again.

[0081] Then, if Figure 7 As shown, the plurality of optical fibers 10 held by the sealing member 35 are inserted from the through hole 31 of the sheath 30 into the interior of the ferrule 20. At this time, the sealing member 35 holding the coating portion 13 of the plurality of optical fibers 10 is inserted into the through hole 31 of the sheath 30 in the X direction. The coating removal portions 12 of the plurality of optical fibers 10 are respectively inserted into the plurality of optical fiber holding holes 25 of the ferrule 20 in the X direction. In this state, the sealing member 35 is configured to block the gap between the inner surface of the through hole 31 and the plurality of optical fibers 10 when viewed in the X direction.

[0082] Then, if Figure 8 As shown, liquid adhesive A is injected from the window 28 of the ferrule 20 into the internal space R of the ferrule 20. At this time, the interior of the through hole 31 is sealed by the sealing member 35, so that the liquid adhesive A is prevented from leaking out of the ferrule 20 along the multiple optical fibers 10 inserted into the through hole 31. Therefore, the adhesive A is filled in the internal space R and does not flow out to the rear of the sealing member 35. In this state, the adhesive A is cured, and the multiple optical fibers 10 are fixed to the ferrule 20, thereby obtaining Figure 2 The optical connector 1 is shown.

[0083] Effects obtained by the optical connector 1 , the optical coupling structure 100 , and the method for manufacturing the optical connector 1 according to the present embodiment described above will be described together with problems of the comparative example.

[0084] Fig. 9 2 is a cross-sectional view of an optical connector 200 according to a comparative example. Fig.10 It is along Fig. 9 A cross-sectional view of an optical connector 200 taken along line X-X. Unlike the optical connector 1 of the present embodiment, the optical connector 200 does not include a sealing member 35. In this case, a plurality of optical fibers 10 are inserted from the through hole 31 of the sheath 30 into the interior of the ferrule 20 in a state where they are spread out into single cores for rotational alignment. When the plurality of optical fibers 10 are inserted into the through hole 31 in a spread out state, it is difficult to maintain a state where the plurality of optical fibers 10 are meticulously arranged side by side in the Y direction inside the through hole 31. Therefore, as Fig.10As shown, the optical fibers 10 are easily overlapped.

[0085] If such overlap of the optical fibers 10 occurs, a gap is likely to be generated between the inner surface of the through hole 31 and the optical fiber 10. In this case, when the liquid adhesive A is injected into the inside of the ferrule 20, the adhesive A is likely to leak out of the ferrule 20 along the optical fiber 10 from the gap. If the adhesive A leaked out of the ferrule 20 is cured while being attached to the optical fiber 10, the flexibility of the optical fiber 10 will be lost, and the resistance of the optical fiber 10 to bending may be reduced. As a result, when bending stress is applied to the optical fiber 10, the optical fiber 10 may be easily broken.

[0086] In contrast, in this embodiment, if Figure 2 and Figure 3 As shown in FIG. 1 , a sealing member 35 is provided in the jacket 30, and the sealing member 35 is configured to block the gap between the inner surface of the through hole 31 and the plurality of optical fibers 10 when viewed in the X direction. Therefore, when the liquid adhesive A is injected into the internal space R of the ferrule 20, the adhesive A can be prevented from leaking out of the ferrule 20 through the gap between the inner surface of the through hole 31 and the plurality of optical fibers 10. If a configuration in which such a sealing member 35 is provided is adopted, the sealing member 35 can prevent the adhesive A from flowing out of the ferrule 20. Thus, the adhesive A leaking out of the ferrule 20 can be prevented from being cured while being attached to the optical fiber 10. As a result, the reduction in the bending resistance of the optical fiber 10 due to the curing of the leaked adhesive A can be suppressed.

[0087] As in the present embodiment, the sealing member 35 may be arranged inside the through hole 31, and may cover the plurality of optical fibers 10 at once. In this case, the plurality of optical fibers 10 are inserted into the through hole 31 in a state where the plurality of optical fibers 10 are covered at once by the sealing member 35, and thus the sealing member 35 can be arranged to block the gap between the inner surface of the through hole 31 and the plurality of optical fibers 10. If the plurality of optical fibers 10 are covered at once by the sealing member 35 before being inserted into the through hole 31 in this way, the plurality of optical fibers 10 that have been rotationally aligned can be collectively inserted into the through hole 31 in an aligned state. In this case, compared with the case where the plurality of optical fibers 10 are inserted into the through hole 31 in a state where they are spread out into single cores for rotational alignment, the insertion operation of the plurality of optical fibers 10 into the ferrule 20 can be easily performed. Furthermore, if the plurality of optical fibers 10 are arranged using the sealing member 35, the plurality of optical fibers 10 can be arranged so that they do not overlap each other inside the through hole 31. This can more reliably suppress the adhesive A from leaking out of the ferrule 20 from the gaps formed between the plurality of optical fibers 10 .

[0088] As in the present embodiment, the sealing member 35 may be made of a material different from that of the adhesive A. A relatively hard material is suitable as the material of the adhesive A to fix the plurality of optical fibers 10 to the ferrule 20. On the other hand, a relatively soft material is suitable as the material of the sealing member 35 provided in the sheath 30 to ensure the bending resistance of the optical fiber 10. Therefore, by using a material different from that of the adhesive A as the material of the sealing member 35 in consideration of the difference in respective uses, a material suitable for the type of the sealing member 35 can be selected.

[0089] As in the present embodiment, the coating portions 13 of the plurality of optical fibers 10 may extend to the outside of the ferrule 20 on the side opposite to the internal space R relative to the sealing member 35 in the X direction, and may be collectively covered with the tape resin 18 on the outside. By collectively covering the coating portions 13 of the plurality of optical fibers 10 extending to the outside with the tape resin 18 in this way, the coating portions 13 of the plurality of optical fibers exposed to the outside can be protected from external forces.

[0090] As in the present embodiment, the optical fiber 10 may be any one of a multi-core optical fiber, a polarization-maintaining optical fiber, and a bundled optical fiber. When such an optical fiber 10 that needs to be rotated and aligned is used, it is easy for the optical fibers 10 to overlap with each other. In contrast, in the above-mentioned optical connector, even when the optical fibers 10 overlap with each other, it is possible to suppress the adhesive A from leaking out of the ferrule 20. Thus, it is possible to suppress the reduction in the bending resistance of the optical fiber 10 due to the solidification of the leaked adhesive A.

[0091] [Second embodiment]

[0092] Next, an optical connector 1A according to a second embodiment will be described. In the following description of the second embodiment, description of portions overlapping with the first embodiment will be appropriately omitted, and portions different from the first embodiment will be mainly described.

[0093] Fig.11 It is a cross-sectional view of an optical connector 1A according to the second embodiment. Fig.12 It is along Fig.11A cross-sectional view of the optical connector 1A taken along line XII-XII of FIG. In the optical connector 1A of the second embodiment, unlike the optical connector 1 of the first embodiment, the sealing member 35A is not arranged inside the through hole 31 of the sheath 30, but is arranged outside the through hole 31. Specifically, the sealing member 35A is provided on the rear surface 33 of the sheath 30, and is arranged to block the opening 33a formed on the rear surface 33. The sealing member 35A is arranged to block the opening 33a, which means that the opening 33a is covered in a manner that fills the gap between the outer edge of the opening 33a and the coating 13 of the plurality of optical fibers 10 when viewed in the X direction. As a result, the sealing member 35A is arranged to block the gap between the inner surface of the through hole 31 and the coating 13 of the plurality of optical fibers 10 when viewed in the X direction.

[0094] exist Fig.12 The outer edge of the sealing member 35A is shown by a dotted line. Fig.12 As shown, when viewed in the X direction, the sealing member 35A has a size that includes the through hole 31 of the sheath 30. The sealing member 35A viewed in the X direction may be larger than the through hole 31 and smaller than the sheath 30. The sealing member 35A viewed in the X direction may have a size that includes the tape resin 18. The sealing member 35A is in contact with the rear surface 33 and has a prescribed thickness in the X direction from the rear surface 33. The sealing member 35A is, for example, arranged between the rear surface 33 and the tape resin 18 in the X direction. In this case, the sealing member 35A may be in contact with the rear surface 33 and the tape resin 18 in the X direction. The sealing member 35A may also be arranged to cover the tape resin 18. In this case, the sealing member 35A may be in contact with the outer peripheral surface of the tape resin 18.

[0095] Next, refer to Fig.13 , Fig.14 , Fig.15 as well as Fig.16 A method for manufacturing the optical connector 1A will be described. Fig.13 It is a plan view showing the manufacturing process of the optical connector 1A. Fig.14 Yes means Fig.13 A cross-sectional view of a subsequent manufacturing process. Fig.15 Yes means Fig.14 A cross-sectional view of a subsequent manufacturing process. Fig.16 Yes means Fig.15 A cross-sectional view of a subsequent manufacturing process.

[0096] First, if Fig.13As shown in FIG. 1 , in order to rotationally align the plurality of optical fibers 10 included in the optical fiber ribbon T, the plurality of optical fibers 10 in the portion of the optical fiber ribbon T to be inserted into the ferrule 20 are changed from a ribbonized state to a spread-out state of single cores. At this time, the ribbonized resin 18 remains behind the coating 13 of the plurality of optical fibers 10. In this state, the plurality of optical fibers 10 are rotationally aligned around the central axis L.

[0097] Then, if Fig.14 As shown, the plurality of optical fibers 10 in a state of being spread out into single cores are inserted from the through hole 31 of the sheath 30 into the interior of the ferrule 20. At this time, the coating portions 13 of the plurality of optical fibers 10 are inserted into the through hole 31 of the sheath 30 in the X direction, and the coating removal portions 12 of the plurality of optical fibers 10 are respectively inserted into the plurality of optical fiber holding holes 25 of the ferrule 20 in the X direction. In this state, the tape resin 18 is arranged outside the through hole 31.

[0098] Then, if Fig.15 As shown, the material of the sealing member 35A is applied around the plurality of optical fibers 10 in a manner to block the openings 33a of the rear surface 33 of the jacket 30. The material of the sealing member 35A is cured in a state where the openings 33a are blocked by the material of the sealing member 35A, thereby forming the sealing member 35A configured to block the gap between the inner surface of the through hole 31 and the plurality of optical fibers 10 when viewed in the X direction.

[0099] Then, if Fig.16 As shown, liquid adhesive A is injected into the internal space R of the ferrule 20 from the window 28 of the ferrule 20. At this time, the opening 33a of the through hole 31 is sealed by the sealing member 35A, thereby preventing the liquid adhesive A from leaking out of the ferrule 20 along the multiple optical fibers 10 inserted into the through hole 31. Therefore, the adhesive A is filled in the internal space R and does not flow out to the rear of the sealing member 35A. In this state, the adhesive A is cured, and the multiple optical fibers 10 are fixed to the ferrule 20, thereby obtaining Fig.11 The optical connector 1A is shown.

[0100] According to the optical connector 1A of the present embodiment, even when the optical fibers 10 overlap each other, the sealing member 35A can prevent the adhesive A from flowing out of the ferrule 20. Thus, it is possible to prevent the adhesive A leaking out of the ferrule 20 from being cured while being attached to the optical fiber 10. As a result, it is possible to prevent the bending resistance of the optical fiber 10 from being reduced due to the curing of the leaked adhesive A.

[0101] As in the present embodiment, the sealing member 35A may block the opening 33a formed on the rear surface 33 of the sheath 30. In this case, after inserting the plurality of optical fibers 10 into the through-hole 31 of the sheath 30, a simple operation of applying the material of the sealing member 35A in a manner to block the opening 33a of the rear surface 33 of the sheath 30 is performed, so that the sealing member 35A configured to block the gap between the inner surface of the through-hole 31 and the plurality of optical fibers 10 can be easily formed.

[0102] In the present embodiment, the sealing member 35A may be formed on the front surface 32 of the sheath 30 instead of the rear surface 33 of the sheath 30. In this case, the sealing member 35A is arranged on the front surface 32 so as to block the opening 32a formed on the front surface 32. Even in such a form, since the outflow of the adhesive A to the outside of the ferrule 20 can be blocked by the sealing member 35A, the same effect as the above effect can be obtained.

[0103] The present disclosure is not limited to the above-described embodiments, and can be appropriately modified within the scope not departing from the gist described in the claims.

[0104] Fig.17 It is a cross-sectional view of an optical connector 1B according to a modified example of the first embodiment. Fig.18 FIG. 1 is a perspective view of an optical fiber holding member 60 included in an optical connector 1B. The optical connector 1B includes, in addition to the optical connector 1 of the first embodiment, Fig.18 The optical fiber holding member 60 is shown. The optical fiber holding member 60 is formed as a separate body from the ferrule 20, and the optical fiber holding member 60 is arranged inside the ferrule 20. The optical fiber holding member 60 is made of a material such as resin or metal. The optical fiber holding member 60 includes, for example, a front surface 60a, a rear surface 60b, an upper surface 60c, a lower surface 60d, a side surface 60e, and a side surface 60f.

[0105] The front surface 60a is an end surface at the front end of the optical fiber holding component 60 located in the X direction. The rear surface 60b is an end surface at the rear end of the optical fiber holding component 60 located in the X direction. The front surface 60a and the rear surface 60b are, for example, planes along the YZ plane, and are arranged side by side along the X direction. The upper surface 60c is an end surface at the upper end of the optical fiber holding component 60 located in the Z direction. The lower surface 60d is an end surface at the lower end of the optical fiber holding component 60 located in the Z direction. The upper surface 60c and the lower surface 60d are, for example, planes along the XY plane, and are arranged side by side along the Z direction. The side surface 60e is an end surface at one end of the optical fiber holding component 60 located in the Y direction. The side surface 60f is an end surface at the other end of the optical fiber holding component 60 located in the Y direction. The side surface 60e and the side surface 60f are, for example, planes along the XZ plane, and are arranged side by side along the Y direction.

[0106] The optical fiber holding member 60 has a fixing surface 60g for collectively fixing the coating portions 13 of the plurality of optical fibers 10 in a portion close to the rear surface 60b in the X direction. The fixing surface 60g is, for example, a plane along the XY plane, and is stepped relative to the upper surface 60c. The fixing surface 60g is connected to the upper surface 60c via a stepped surface 60s. The stepped surface 60s is, for example, a plane along the YZ plane, and is formed to be perpendicular to the fixing surface 60g and the upper surface 60c. The fixing surface 60g extends from the stepped surface 60s to the rear surface 60b in the X direction. The optical fiber holding member 60 has a plurality of V-grooves 60h for respectively holding the coating removal portions 12 of the plurality of optical fibers 10 in a portion close to the rear surface 60b in the X direction. The plurality of V-grooves 60h are formed on the upper surface 60c. The plurality of V-grooves 60h extend from the front surface 60a to the stepped surface 60s in the X direction on the upper surface 60c, and are arranged side by side in the Y direction.

[0107] like Fig.17 As shown, the optical fiber holding member 60 is arranged inside the ferrule 20 from the jacket insertion hole 24 of the ferrule 20. The optical fiber holding member 60 is arranged inside the ferrule 20 between the plurality of optical fiber holding holes 25 and the jacket 30. For example, the front surface 60a of the optical fiber holding member 60 is separated from the wall surface 26 in which the plurality of optical fiber holding holes 25 are formed. The rear surface 60b of the optical fiber holding member 60 is in contact with the front surface 32 of the jacket 30. The optical fiber holding member 60 holds the plurality of optical fibers 10 extending between the wall surface 26 and the front surface 32. The coating removal portions 12 of the plurality of optical fibers 10 are respectively accommodated in the plurality of V-grooves 60h of the optical fiber holding member 60. The coating portions 13 of the plurality of optical fibers 10 are placed on the fixing surface 60g of the optical fiber holding member 60. A rectangular plate-shaped cover 61 covering the coating portions 13 of the plurality of optical fibers 10 is provided on the plurality of V-grooves 60h. The cover removal portion 12 and the cover portion 13 are fixed to the V-groove 60h and the fixing surface 60g, respectively, by an adhesive.

[0108] Even in such a form, the same effect as the optical connector 1 of the first embodiment can be obtained. That is, the outflow of the adhesive A to the outside of the ferrule 20 can be blocked by the sealing member 35, so that the adhesive A leaked to the outside of the ferrule 20 can be suppressed from solidifying while being attached to the optical fiber 10. As a result, the reduction in the bending resistance of the optical fiber 10 due to the solidification of the leaked adhesive A can be suppressed. Moreover, if the optical fiber holding component 60 as described above is arranged inside the ferrule 20, the insertion operation of multiple optical fibers 10 into the ferrule 20 becomes easy. Moreover, the optical fiber holding component 60 has multiple V-grooves 60h. In this case, by accommodating the multiple optical fibers 10 in the multiple V-grooves 60h, respectively, the positions and rotation angles of the multiple optical fibers 10 relative to the ferrule 20 can be accurately determined.

[0109] Fig.19It is a cross-sectional view of an optical connector 1C according to another modified example of the first embodiment. Fig. 20 1C is a perspective view of an optical fiber holding member 60A provided in the optical connector 1C. Fig. 20 The optical fiber holding component 60A replaces the optical fiber holding component 60 of the optical connector 1B. The optical fiber holding component 60A is different from the optical fiber holding component 60 and does not have a fixing surface 60g. The upper surface 60c extends from the front surface 60a to the rear surface 60b. The multiple V-grooves 60i formed on the upper surface 60c extend from the front surface 60a to the rear surface 60b. The coating portions 13 of the multiple optical fibers 10 extending between the wall surface 26 and the front surface 32 of the sheath 30 are accommodated in the multiple V-grooves 60i. A rectangular plate-shaped cover 61 covering the coating portions 13 of the multiple optical fibers 10 is provided on the multiple V-grooves 60i. Even in such a form, the same effect as the optical connector 1 of the first embodiment can be obtained. The optical fiber holding component 60A can also have multiple V-grooves that respectively accommodate the coating removal portions 12 of the multiple optical fibers 10 extending between the wall surface 26 and the front surface 32.

[0110] Fig.21 It is a cross-sectional view of an optical connector 1D according to another modified example of the first embodiment. Fig. 22 1D is a perspective view showing an optical fiber holding member 60B included in the optical connector 1D. Fig. 22 The optical fiber holding component 60B replaces the optical fiber holding component 60 of the optical connector 1B. The optical fiber holding component 60B is different from the optical fiber holding component 60 and does not have a fixing surface 60g. The upper surface 60c extends from the front surface 60a to the rear surface 60b. The optical fiber holding component 60B has a plurality of optical fiber through holes 62 instead of the plurality of V-grooves 60h. The plurality of optical fiber through holes 62 penetrate from the front surface 60a to the rear surface 60b in the X direction and are arranged side by side along the Y direction. The plurality of optical fibers 10 are respectively inserted into the plurality of optical fiber through holes 62.

[0111] like Fig. 22As shown, each optical fiber through hole 62 has, for example, a thin-diameter portion 62a and a thick-diameter portion 62b. The coating removal portion 12 of the optical fiber 10 extending between the wall surface 26 and the front surface 32 of the jacket 30 is inserted into the thin-diameter portion 62a. The thick-diameter portion 62b has an inner diameter larger than the inner diameter of the thin-diameter portion 62a. The coating portion 13 of the optical fiber 10 extending between the wall surface 26 and the front surface 32 of the jacket 30 is inserted into the thick-diameter portion 62b. Even in such a form, the same effect as the optical connector 1 of the first embodiment can be obtained. Furthermore, if an optical fiber holding component 60B having a plurality of optical fiber through holes 62 is used, by inserting a plurality of optical fibers 10 into the plurality of optical fiber through holes 62, respectively, the positions and rotation angles of the plurality of optical fibers 10 relative to the ferrule 20 can be accurately determined. The optical fiber through hole 62 may have only the thin-diameter portion 62a, or the coating removal portion 12 may be held only by the thin-diameter portion 62a. Alternatively, the optical fiber through hole 62 may include only the large-diameter portion 62 b , and the coating portion 13 may be held only by the large-diameter portion 62 b .

[0112] Fig.23 2 is a cross-sectional view showing a modified example of the optical fiber holding component 60. Fig.23 As shown, an optical fiber holding component 60C can also be used as a modified example of the optical fiber holding component 60. The optical fiber holding component 60C is a resin layer that covers the coatings 13 of multiple optical fibers 10 extending between the wall surface 26 and the front surface 32 of the sheath 30, that is, a resin layer that covers the coatings 13 of multiple optical fibers 10 in a bundled manner in a row. The optical fiber holding component 60C integrally holds the coatings 13 of multiple optical fibers 10. The optical fiber holding component 60C can be made of the same material as the tape resin 18, for example. Even in such a form, the same effect as the optical connector 1 of the first embodiment can be obtained. Moreover, by covering the coatings 13 of multiple optical fibers 10 with the optical fiber holding component 60C, the bending resistance of each optical fiber 10 can be ensured.

[0113] Fig.24 FIG. 4 is a cross-sectional view showing another modified example of the optical fiber holding component 60. Fig.24 As shown, an optical fiber holding component 60D can also be used as a modified example of the optical fiber holding component 60. The optical fiber holding component 60D is a resin layer that covers the coating removal portions 12 of multiple optical fibers 10 extending between the wall surface 26 and the front surface 32 of the sheath 30, that is, a resin layer that covers the coating removal portions 12 of multiple optical fibers 10 in a manner of bundling them in a row. The optical fiber holding component 60D integrally holds the coating removal portions 12 of multiple optical fibers 10. The optical fiber holding component 60D can be made of the same material as the tape resin 18, for example. Even in such a form, the same effect as the optical connector 1 of the first embodiment can be obtained. Moreover, by covering the coating removal portions 12 of multiple optical fibers 10 with the optical fiber holding component 60D, the bending resistance of each optical fiber 10 can be ensured.

[0114] Fig.25 FIG. 1 is a cross-sectional view of an optical connector 1E according to a modified example of the second embodiment. The optical connector 1E includes, in addition to the optical connector 1A according to the second embodiment, Fig.18 The optical fiber holding component 60 shown. Similar to the optical connector 1A, the optical fiber holding component 60 is arranged between the plurality of optical fiber holding holes 25 and the sheath 30 inside the ferrule 20. The optical fiber holding component 60 holds the plurality of optical fibers 10 extending between the wall surface 26 and the front surface 32 of the sheath 30. The coating removal portions 12 of the plurality of optical fibers 10 are respectively accommodated in the plurality of V-grooves 60h of the optical fiber holding component 60. The coating portions 13 of the plurality of optical fibers 10 are placed on the fixing surface 60g of the optical fiber holding component 60. In the optical connector 1E, after the plurality of optical fibers 10 are inserted into the ferrule 20 in this way, a sealing member 35A is formed to block the opening 33a of the rear surface 33 of the sheath 30.

[0115] Even in such a form, the same effect as that of the optical connector 1A of the second embodiment can be obtained. That is, the outflow of the adhesive A to the outside of the ferrule 20 can be blocked by the sealing member 35A, so that the adhesive A leaking out of the ferrule 20 can be prevented from being cured while being attached to the optical fiber 10. As a result, the reduction in the bending resistance of the optical fiber 10 due to the curing of the leaked adhesive A can be suppressed. In addition, if the sealing member 35A is configured to block the opening 33a of the rear surface 33 of the sheath 30, the sealing member 35A configured to block the gap between the inner surface of the through hole 31 and the plurality of optical fibers 10 can be easily formed by applying the material of the sealing member 35A in a manner that blocks the opening 33a of the rear surface 33 of the sheath 30. The optical connector 1E may also include any one of the optical fiber holding member 60A, the optical fiber holding member 60B, the optical fiber holding member 60C, and the optical fiber holding member 60D instead of the optical fiber holding member 60.

[0116] Description of Reference Numerals

[0117] 1, 1A, 1B, 1C, 1D, 1E: optical connector; 1a: first optical connector; 1b: second optical connector; 10: optical fiber; 11: top surface; 12: cover removal portion; 13: cover portion; 15: resin cover; 16: cladding; 17: fiber core; 18: tape resin; 20: ferrule; 21: front end surface; 22: rear end surface; 22a, 32a, 33a, 50a: opening; 23: guide hole; 24: jacket insertion hole; 25: optical fiber holding hole; 26: wall surface; 27, 60c: upper surface; 28: window; 30: guard Sleeve; 31: through hole; 32, 60a: front surface; 33, 60b: rear surface; 35, 35A: sealing member; 40: guide pin; 50: spacer; 60, 60A, 60B, 60C, 60D: optical fiber holding member; 60d: lower surface; 60e, 60f: side surface; 60g: fixing surface; 60s: step surface; 62a: thin diameter portion; 62b: thick diameter portion; 60h, 60i: V-groove; 62: optical fiber through hole; 100: optical coupling structure; A: adhesive; L: center axis; R: internal space; T: optical fiber ribbon.

Claims

1. An optical connector comprising: A ferrule having a front end and a rear end facing each other in one direction, and having a sheath insertion hole formed at the rear end and a plurality of optical fiber holding holes extending from the sheath insertion hole toward the front end; a sheath having a through hole extending in the one direction, wherein the sheath is inserted into the sheath insertion hole from the rear end; as well as a plurality of optical fibers, each having at least one of a core and a stress imparting portion at a position offset from the respective central axis, the plurality of optical fibers being inserted into the through hole in the one direction and being respectively held in the plurality of optical fiber holding holes, An adhesive for fixing the plurality of optical fibers to the ferrule is provided inside the ferrule between the sheath and the front end. The sheath is provided with a sealing member, and the sealing member is configured to close a gap between an inner surface of the through hole and the plurality of optical fibers when viewed in the one direction.

2. The optical connector according to claim 1, wherein: The sealing member is disposed inside the through hole and covers the plurality of optical fibers.

3. The optical connector according to claim 1, wherein: The sealing member is provided on a rear surface of the sheath facing a side opposite to the plurality of optical fiber holding holes in the one direction, and closes the opening of the through hole formed in the rear surface.

4. The optical connector according to any one of claims 1 to 3, wherein: The sealing member is made of a material different from that of the adhesive.

5. The optical connector according to any one of claims 1 to 4, wherein: The plurality of optical fibers each have a coating portion covered by a coating, The coating portions of the plurality of optical fibers extend toward the outside of the ferrule on the side opposite to the inside of the ferrule relative to the sealing member in the one direction, and are covered with a resin layer at the outside.

6. The optical connector according to any one of claims 1 to 5, further comprising: The optical fiber holding member is disposed inside the ferrule between the plurality of optical fiber holding holes and the sheath, and holds the plurality of optical fibers.

7. The optical connector according to claim 6, wherein: The plurality of optical fibers each have a coating portion covered by a coating, The optical fiber holding member is a resin layer that covers the coating portions of the plurality of optical fibers.

8. The optical connector according to claim 6, wherein: Each of the plurality of optical fibers has a coating removed portion obtained by removing a predetermined length of the coating from the distal end surface. The optical fiber holding member is a resin layer that covers the coating-removed portions of the plurality of optical fibers.

9. The optical connector according to claim 6, wherein: The optical fiber holding member has a plurality of V-grooves extending in the one direction, The plurality of optical fibers are respectively accommodated in the plurality of V-grooves.

10. The optical connector according to claim 6, wherein: The optical fiber holding member has a plurality of optical fiber through holes penetrating in the one direction. The plurality of optical fibers are inserted into the plurality of optical fiber through holes.

11. The optical connector according to any one of claims 1 to 10, wherein: The optical fiber is any one of a multi-core optical fiber, a polarization-maintaining optical fiber and a bundle optical fiber.

12. An optical coupling structure comprising a first optical connector and a second optical connector as claimed in any one of claims 1 to 11, The first optical connector is arranged to be opposed to the second optical connector in the one direction and optically coupled to the second optical connector.

13. A method for manufacturing an optical connector, comprising the following steps: Prepare a ferrule, a sheath and multiple optical fibers, wherein: The ferrule has a front end and a rear end facing each other in one direction, and has a sheath insertion hole formed in the rear end and a plurality of optical fiber holding holes extending from the sheath insertion hole toward the front end, the sheath has a through hole penetrating in the one direction and is inserted from the rear end into the sheath insertion hole, and the plurality of optical fibers each have at least one of a core and a stress applying portion at a position offset from their respective central axes; Inserting the plurality of optical fibers into the interior of the ferrule in such a manner that the plurality of optical fibers are inserted into the through holes and are respectively held in the plurality of optical fiber holding holes; forming a sealing member, wherein the sealing member is configured to block a gap between an inner surface of the through hole and the plurality of optical fibers when viewed in the one direction; as well as An adhesive for fixing the plurality of optical fibers to the ferrule is injected into the interior of the ferrule between the sheath and the front end, thereby fixing the plurality of optical fibers to the ferrule.

14. The method for manufacturing an optical connector according to claim 13, wherein: The step of inserting the plurality of optical fibers into the ferrule is performed after the step of forming the sealing member and before the step of fixing the plurality of optical fibers to the ferrule. In the step of forming the sealing member, the sealing member is formed to cover the plurality of optical fibers. In the step of inserting the plurality of optical fibers into the ferrule, the sealing member is disposed inside the through-hole when the plurality of optical fibers are inserted into the through-hole.

15. The method for manufacturing an optical connector according to claim 13, wherein: The step of forming the sealing member is performed after the step of inserting the plurality of optical fibers into the ferrule and before the step of fixing the plurality of optical fibers to the ferrule. In the process of forming the sealing member, after the multiple optical fibers are inserted into the through holes, the sealing member is formed on the rear surface of the sheath facing the side opposite to the multiple optical fiber holding holes in the one direction in such a manner as to block the opening of the through holes formed on the rear surface.

Images