WO2021065224A1 - Ferrule, optical connector, and method for manufacturing optical connector - Google Patents

Ferrule, optical connector, and method for manufacturing optical connector Download PDF

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Publication number
WO2021065224A1
WO2021065224A1 PCT/JP2020/031071 JP2020031071W WO2021065224A1 WO 2021065224 A1 WO2021065224 A1 WO 2021065224A1 JP 2020031071 W JP2020031071 W JP 2020031071W WO 2021065224 A1 WO2021065224 A1 WO 2021065224A1
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WO
WIPO (PCT)
Prior art keywords
ferrule
fiber
hole
adhesive
fiber hole
Prior art date
Application number
PCT/JP2020/031071
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French (fr)
Japanese (ja)
Inventor
章浩 中間
大貴 朝田
Original Assignee
株式会社フジクラ
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Publication date
Application filed by 株式会社フジクラ filed Critical 株式会社フジクラ
Publication of WO2021065224A1 publication Critical patent/WO2021065224A1/en

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    • G—PHYSICS
    • G02—OPTICS
    • G02B—OPTICAL ELEMENTS, SYSTEMS OR APPARATUS
    • G02B6/00—Light guides; Structural details of arrangements comprising light guides and other optical elements, e.g. couplings
    • G02B6/24—Coupling light guides
    • G02B6/26—Optical coupling means
    • G02B6/32—Optical coupling means having lens focusing means positioned between opposed fibre ends
    • G—PHYSICS
    • G02—OPTICS
    • G02B—OPTICAL ELEMENTS, SYSTEMS OR APPARATUS
    • G02B6/00—Light guides; Structural details of arrangements comprising light guides and other optical elements, e.g. couplings
    • G02B6/24—Coupling light guides
    • G02B6/36—Mechanical coupling means

Definitions

  • the present invention relates to a ferrule, an optical connector, and a method for manufacturing an optical connector.
  • the present application claims priority based on Japanese Patent Application No. 2019-181313 filed in Japan on October 1, 2019, the contents of which are incorporated herein by reference.
  • Patent Document 1 discloses a ferrule that holds an end portion of an optical fiber.
  • the ferrule has a fiber hole for inserting a bare portion of an optical fiber and an adhesive filling portion formed so as to be connected to the first end in the longitudinal direction of the fiber hole.
  • the bare portion of the optical fiber is inserted into the fiber hole from the first end of the fiber hole to reach the second end in the longitudinal direction of the fiber hole.
  • the adhesive is filled in the adhesive filling portion, and the adhesive is cured to fix the optical fiber to the ferrule.
  • the adhesive filled in the adhesive filling portion may reach or near the second end of the fiber hole through the gap between the fiber hole and the optical fiber inserted therein. Therefore, as the adhesive shrinks during curing, the tip of the optical fiber located on the second end side of the fiber hole receives a force from the side, and the axial direction of the optical fiber at the tip of the optical fiber is fiber. It may tilt with respect to the axial direction of the hole. In this case, for example, there is a problem that the coupling efficiency of optical signals between connectors is lowered.
  • the present invention has been made in view of the above circumstances, and provides a ferrule capable of suppressing the inclination of the tip of an optical fiber inside a fiber hole, an optical connector provided with the ferrule, and a method for manufacturing the optical connector.
  • the purpose is to do.
  • the ferrule according to one aspect of the present invention is a ferrule having a fiber hole into which a bare portion of an optical fiber is inserted, includes a ferrule body in which the fiber hole is formed, and the ferrule body is filled with an adhesive.
  • An adhesive filling portion and an intermediate cavity portion are formed, and the adhesive filling portion and the intermediate cavity portion communicate with the fiber hole, and in a cross section orthogonal to the longitudinal direction of the fiber hole, the intermediate portion is formed.
  • the cross-sectional area of the cavity is larger than the cross-sectional area of the fiber hole, and the intermediate cavity is located in the middle of the fiber hole in the longitudinal direction.
  • the adhesive filled in the adhesive filling portion even if the adhesive filled in the adhesive filling portion enters the gap between the fiber hole and the optical fiber and advances in the fiber hole due to capillary force or the like, the adhesive stays outside the fiber hole in the intermediate cavity portion. Is discharged to. Therefore, it is possible to prevent or prevent the adhesive from reaching the second end of the fiber hole or its vicinity. As a result, it is possible to prevent the axial direction of the optical fiber at the tip of the optical fiber from being inclined with respect to the axial direction of the fiber hole due to shrinkage during curing of the adhesive.
  • the intermediate cavity may open to the outside of the ferrule body.
  • the fiber hole is divided into a first division hole and a second division hole which are arranged in order from the adhesive filling portion side in the longitudinal direction by the intermediate cavity portion, and the first division hole in the longitudinal direction.
  • the length of the bipartition hole may be longer than the length of the first division hole in the longitudinal direction.
  • the length of the fiber hole in the longitudinal direction may be longer than the length of the adhesive filling portion in the longitudinal direction.
  • the ferrule may further include a lens portion facing the end of the fiber hole on the opposite side of the adhesive filling portion.
  • the fiber hole opens in the front end surface of the ferrule body, and the rear end surface of the lens portion faces the front end surface of the ferrule body in the longitudinal direction and is spaced from the front end surface. May be arranged with an opening.
  • the optical connector according to one aspect of the present invention includes the ferrule, an optical fiber including a bare portion inserted into the fiber hole, and an adhesive filled in the adhesive filling portion to fix the optical fiber to the ferrule. And.
  • the method for manufacturing an optical connector according to one aspect of the present invention is a method for manufacturing an optical connector in which an optical fiber including a bare portion is attached to the ferrule to manufacture an optical connector, and the bare portion is inserted into the fiber hole.
  • the optical fiber is fixed to the ferrule by filling the adhesive filling portion with an adhesive and curing the adhesive.
  • the inclination of the tip of the optical fiber due to the shrinkage of the adhesive can be suppressed.
  • FIG. 6 is a cross-sectional view taken along the line VII-VII of FIG.
  • the ferrule 1 of the present embodiment includes a ferrule main body 10 and a lens unit 20.
  • the ferrule 1 is attached to the tip of an optical fiber 2 (see FIG. 5) and is used to optically couple the optical fiber 2 to another optical component (eg, optical fiber, optical waveguide, etc.).
  • the ferrule 1 and the optical fiber 2 are collectively referred to as an "optical connector".
  • the optical fiber 2 has a bare portion 2A and a covering portion 2B (see FIG. 5).
  • the bare portion 2A has a core and a clad (not shown), and is formed of glass or the like.
  • the covering portion 2B covers the bare portion 2A and is formed of a resin or the like. The covering portion 2B is not provided at the tip end portion of the optical fiber 2, and the bare portion 2A is exposed.
  • the ferrule body 10 has a fiber hole 11, an adhesive filling portion 12, and an intermediate cavity portion 13.
  • the longitudinal direction (X-axis direction) of the fiber hole 11 may be simply referred to as the longitudinal direction.
  • the tip side of the X-axis arrow may be referred to as the "front side", and the opposite side may be referred to as the "rear side”.
  • the ferrule 1 is located at the front end of the optical connector, and the optical fiber extends from the ferrule 1 to the rear.
  • the bare portion 2A of the optical fiber 2 is inserted into the fiber hole 11.
  • the adhesive filling portion 12 is filled with the adhesive 3 (see FIG. 5).
  • the intermediate cavity portion 13 is formed in the intermediate portion of the fiber hole 11 in the longitudinal direction (X-axis direction).
  • the ferrule body 10 of the present embodiment further has a boot storage portion 14.
  • the fiber hole 11 is formed in a straight line so that the bare portion 2A of one optical fiber 2 can be inserted.
  • the inner diameter of the fiber hole 11 is slightly larger than the outer diameter of the bare portion 2A. Therefore, when the bare portion 2A is inserted into the fiber hole 11, a gap is generated between the inner circumference of the fiber hole 11 and the outer circumference of the bare portion 2A. As a result, the bare portion 2A inserted into the fiber hole 11 can be advanced in the longitudinal direction of the fiber hole 11.
  • the fiber hole 11 has a first end 11A and a second end 11B.
  • the first end 11A is an end portion that serves as an entrance when the optical fiber 2 is inserted into the fiber hole 11.
  • the adhesive filling portion 12 is located behind the first end 11A.
  • the second end 11B is the end of the fiber hole 11 on the side opposite to the first end 11A.
  • the first end 11A is formed with a series of guide portions 15 for guiding the bare portion 2A to the fiber hole 11.
  • the guide portion 15 is located between the fiber hole 11 and the adhesive filling portion 12 in the longitudinal direction of the fiber hole 11.
  • the guide portion 15 is a hole extending along the longitudinal direction of the fiber hole 11.
  • the inner diameter of the guide portion 15 is larger than the inner diameter of the fiber hole 11.
  • An inclined surface is provided at the connecting portion between the guide portion 15 and the first end 11A.
  • the second end 11B of the fiber hole 11 in the present embodiment is open to the front end surface 10B of the ferrule body 10.
  • the front end surface 10B faces the lens portion 20 in the longitudinal direction.
  • the second end 11B of the fiber hole 11 does not have to be opened to the outside of the ferrule body 10, for example.
  • the fiber hole 11 is divided into a first dividing hole 111 and a second dividing hole 112 by an intermediate cavity portion 13.
  • the first dividing hole 111 and the second dividing hole 112 are arranged in order from the adhesive filling portion 12 side, which will be described later, in the longitudinal direction of the fiber hole 11. That is, the first dividing hole 111 is located behind the second dividing hole 112.
  • the length L12 of the second dividing hole 112 in the longitudinal direction is longer than the length L11 of the first dividing hole 111.
  • the number of fiber holes 11 may be one, for example.
  • the number of fiber holes 11 in this embodiment is a plurality (12 in FIG. 4).
  • the plurality of fiber holes 11 are arranged at intervals in a direction (Y-axis direction) orthogonal to the longitudinal direction thereof.
  • a plurality of optical fibers 2 can be collectively held.
  • the guide portion 15 described above is formed for each of the plurality of fiber holes 11. That is, the number of guide portions 15 is the same as the number of fiber holes 11.
  • the front-back direction of the ferrule corresponds to the longitudinal direction (X-axis direction) of the fiber hole 11. Further, in the front-rear direction, the first end 11A side of the fiber hole 11 may be referred to as the rear side, and the second end 11B side of the fiber hole 11 may be referred to as the front side. Further, the width direction of the ferrule 1 corresponds to the arrangement direction (Y-axis direction) of the plurality of fiber holes 11. Further, a direction (Z-axis direction) orthogonal to both the front-rear direction and the width direction may be referred to as a vertical direction.
  • the adhesive filling portion 12 is a cavity for filling the adhesive 3.
  • the adhesive 3 is used to fix the optical fiber 2 (particularly the bare portion 2A) to the ferrule 1.
  • the adhesive filling portion 12 is formed on the first end 11A side (rear side) of the fiber hole 11.
  • the adhesive filling portion 12 of the present embodiment communicates with the first end 11A of the fiber hole 11 via the guide portion 15.
  • the adhesive filling portion 12 may be directly connected to, for example, the first end 11A of the fiber hole 11.
  • the same adhesive filling portion 12 corresponds to a plurality of fiber holes 11. That is, one adhesive filling portion 12 communicates with a plurality of fiber holes 11.
  • the adhesive filling portion 12 is open to the outside of the ferrule body 10.
  • the direction in which the adhesive filling portion 12 opens and the number of openings in the adhesive filling portion 12 may be arbitrary.
  • the adhesive filling portion 12 of the present embodiment is open in the vertical direction of the ferrule body 10.
  • the upper opening 12A of the adhesive filling portion 12 functions as, for example, an injection port for injecting the adhesive 3.
  • the lower opening 12B of the adhesive filling portion 12 functions as, for example, a vent for ventilation between the adhesive filling portion 12 and the outside of the ferrule body 10.
  • the boot storage unit 14 shown in FIGS. 2 to 4 is a cavity for storing the boot 4 (see FIG. 5).
  • the boot storage portion 14 is formed so as to be connected to the rear side of the adhesive filling portion 12.
  • the boot storage portion 14 opens to the rear end surface 10A of the ferrule body 10 facing the side opposite to the front end surface 10B.
  • the virtual line BL indicates the boundary between the adhesive filling portion 12 and the boot storage portion 14. That is, the boot storage portion 14 is on the rear side of the virtual line BL, and the adhesive filling portion 12 is on the front side of the virtual line BL.
  • the boot 4 is formed in a tubular shape having an insertion hole 4A through which the optical fiber 2 is passed.
  • the boot 4 is formed of an elastic body such as rubber.
  • the intermediate cavity portion 13 has a cross-sectional area orthogonal to the front-rear direction (longitudinal direction of the fiber hole 11) of the ferrule body 10 and a cross-sectional area larger than the cross-sectional area of the fiber hole 11.
  • the same intermediate cavity portion 13 corresponds to a plurality of fiber holes 11. That is, one intermediate cavity portion 13 communicates with a plurality of fiber holes 11.
  • the widthwise dimension of the intermediate cavity 13 is longer than the length between the two fiber holes 11 arranged at both ends in the width direction among the plurality of fiber holes 11 arranged in the width direction.
  • the intermediate cavity portion 13 is open to the outside of the ferrule body 10.
  • the direction in which the intermediate cavity 13 opens and the number of openings in the intermediate cavity 13 may be arbitrary.
  • the intermediate cavity portion 13 of the present embodiment is open at the top and bottom of the ferrule body 10. That is, the intermediate cavity portion 13 has an upper opening 13A and a lower opening 13B.
  • the length L1 of the fiber hole 11 in the front-rear direction of the ferrule body 10 is longer than the length L2 of the adhesive filling portion 12.
  • the length L1 of the fiber hole 11 is the length from the first end 11A to the second end 11B.
  • the length L2 of the adhesive filling portion 12 is the length from the surface of the adhesive filling portion 12 where the guide portion 15 opens to the boundary (virtual line BL) with the boot storage portion 14.
  • the length L2 of the adhesive filling portion 12 is the length from the surface of the adhesive filling portion 12 where the fiber hole 11 opens to the boundary with the boot storage portion 14. is there.
  • the lens unit 20 is made of a material capable of transmitting an optical signal.
  • the lens portion 20 of this embodiment is made of a transparent resin.
  • the material of the lens portion 20 may be, for example, super engineering plastic.
  • the lens portion 20 includes a plate-shaped portion 21 and a plurality of lens main bodies 22.
  • the plate-shaped portion 21 has a plate-like shape extending in the vertical direction and the width direction, and is integrally formed with the ferrule main body 10.
  • the front end surface 21B of the plate-shaped portion 21 is formed with a recess 23 that is recessed toward the rear side.
  • the recess 23 has a rectangular shape when viewed from the front side.
  • the lens body 22 is integrally formed with the plate-shaped portion 21, and is located inside the recess 23.
  • the lens portion 20 faces the second end 11B of the fiber hole 11 in the front-rear direction. Specifically, the lens portion 20 is arranged so that the rear end surface 21A of the plate-shaped portion 21 faces the front end surface 10B of the ferrule body 10 (particularly, the region where the second end 11B of the fiber hole 11 opens).
  • the rear end surface 21A of the plate-shaped portion 21 may come into contact with, for example, the front end surface 10B of the ferrule body 10, but in the present embodiment, the rear end surface 21A is arranged at intervals with respect to the front end surface 10B of the ferrule body 10.
  • the lens body 22 is positioned so as to line up in the front-rear direction with respect to the fiber hole 11 (or the bare portion 2A of the optical fiber 2 inserted therein).
  • the lens body 22 functions as, for example, a collimating lens. That is, for example, the lens body 22 collects an optical signal incident on the ferrule 1 from the outside (front side) and then inputs the optical signal to the tip portion 2C (see FIG. 5) of the optical fiber 2. Alternatively, the lens body 22 enlarges the beam diameter of the optical signal output from the tip portion 2C of the optical fiber 2 and then outputs the light signal to the outside (front side) of the ferrule 1. As a result, the optical fiber 2 can be optically connected to other optical components.
  • each lens body 22 is a convex lens formed on the front end surface 21B side of the plate-shaped portion 21. Further, a plurality of lens main bodies 22 are arranged in the width direction so as to correspond to the plurality of fiber holes 11. Further, the lens body 22 of the present embodiment is located at the bottom of the recess 23 recessed from the front end surface 21B of the plate-shaped portion 21. As a result, when another optical component (for example, another ferrule) is abutted against the front end surface 21B, it is possible to prevent the lens body 22 from coming into contact with the other optical component and damaging the lens body 22.
  • another optical component for example, another ferrule
  • the ferrule body 10 and the lens portion 20 described above are integrally formed. Therefore, the ferrule body 10 is made of a material capable of transmitting an optical signal like the lens portion 20. As shown in FIGS. 1, 3 and 4, in the present embodiment, the ferrule body 10 and the lens portion 20 are connected to each other at both ends in the width direction. However, the ferrule body 10 and the lens portion 20 may not be connected at both ends in the width direction.
  • the ferrule 1 of the present embodiment further has a pair of guide holes 30 for aligning the ferrule 1 with another optical component (for example, another ferrule).
  • the guide hole 30 may extend at least in the front-rear direction and may open to the front end surface 21B of the ferrule 1 (lens portion 20).
  • the guide hole 30 of the present embodiment also opens to the rear end surface 10A of the ferrule 1 (ferrule main body 10). That is, the guide hole 30 penetrates the ferrule 1 in the front-rear direction.
  • the pair of guide holes 30 of the present embodiment are formed on both sides of the plurality of fiber holes 11 in the width direction.
  • the ferrule 1 and the other optical component can be aligned.
  • the guide pin may be fixed to the ferrule 1 or may be fixed to another optical component.
  • an insertion step of inserting the bare portion 2A of the optical fiber 2 into the fiber hole 11 from the first end 11A of the fiber hole 11 is carried out.
  • the tip portion 2C of the bare portion 2A is brought to reach the second end 11B of the fiber hole 11.
  • the portion of the optical fiber 2 (particularly the bare portion 2A) protruding from the boot 4 to the front side is passed through the boot storage portion 14 and the adhesive filling portion 12 in order from the rear end surface 10A of the ferrule body 10. After that, the bare portion 2A is inserted into the fiber hole 11.
  • the tip portion 2C of the bare portion 2A is projected from the second end 11B of the fiber hole 11 and abutted against the rear end surface 21A of the lens portion 20.
  • the boot 4 is stored in the boot storage portion 14 of the ferrule body 10 at the same time as or after the above-mentioned insertion of the optical fiber 2 into the ferrule body 10. In the state after the insertion step, the portion of the optical fiber 2 (particularly the bare portion 2A) that protrudes rearward from the first end 11A of the fiber hole 11 is located in the adhesive filling portion 12.
  • a filling step of filling the adhesive filling portion 12 of the ferrule body 10 with the adhesive 3 is performed.
  • the adhesive 3 is injected through the opening 12A on the upper side of the adhesive filling portion 12.
  • the adhesive filling portion 12 of the present embodiment has a lower opening 12B, but the adhesive 3 can stay in the adhesive filling portion 12 due to its own viscosity and surface tension.
  • the adhesive 3 injected into the adhesive filling portion 12 may enter the gap between the bare portion 2A and the first dividing hole 111 due to a capillary phenomenon or the like.
  • the adhesive 3 when the adhesive 3 is injected into the adhesive filling portion 12 through the upper opening 12A, the air in the adhesive filling portion 12 can be efficiently released to the outside from the lower opening 12B. As a result, the adhesive 3 can be efficiently filled in the adhesive filling portion 12. In addition, it is possible to suppress or prevent bubbles from remaining in the adhesive filling portion 12.
  • a fixing step of fixing the optical fiber 2 (particularly the bare portion 2A) to the ferrule 1 is carried out by curing the adhesive 3 filled in the adhesive filling portion 12.
  • an adhesive (not shown) serving as a refractive index matching agent is filled in the gap (cavity) between the front end surface 10B of the ferrule body 10 and the rear end surface 21A of the lens portion 20. You may. This step may be performed at least after the tip portion 2C of the optical fiber 2 is abutted against the rear end surface 21A of the lens portion 20.
  • the optical connector 100 of the present embodiment manufactured as described above includes a ferrule 1, an optical fiber 2, and an adhesive 3.
  • the optical connector 100 of the present embodiment also includes the boots 4.
  • the bare portion 2A of the optical fiber 2 is inserted into the fiber hole 11 from the first end 11A of the fiber hole 11 of the ferrule 1.
  • the tip portion 2C of the bare portion 2A protrudes from the second end 11B of the fiber hole 11 and is abutted against the rear end surface 21A of the lens portion 20.
  • the adhesive 3 is filled in the adhesive filling portion 12 of the ferrule 1 to fix the optical fiber 2 (particularly the bare portion 2A) to the ferrule 1.
  • the adhesive 3 fixes a portion of the optical fiber 2 located at the adhesive filling portion 12 to the ferrule 1.
  • the ferrule 1 of the present embodiment includes the ferrule main body 10 in which the fiber hole 11 is formed, and the bare portion 2A of the optical fiber 2 is inserted into the fiber hole 11.
  • the ferrule body 10 is formed with an adhesive filling portion 12 for filling the adhesive 3 and an intermediate cavity portion 13, and the adhesive filling portion 12 and the intermediate cavity portion 13 communicate with the fiber hole 11. ..
  • the cross-sectional area of the adhesive filling portion 12 is larger than the cross-sectional area of the fiber hole 11.
  • the intermediate cavity 13 is located in the middle of the fiber hole 11.
  • the adhesive 3 filled in the adhesive filling portion 12 enters the gap between the fiber hole 11 (particularly the first dividing hole 111) and the optical fiber 2 from the first end 11A of the fiber hole 11. Even if the adhesive 3 advances toward the second end 11B in the fiber hole 11 due to capillary force or the like, the adhesive 3 is discharged to the outside of the fiber hole 11 in the intermediate cavity 13. Therefore, it is possible to prevent or prevent the adhesive 3 from entering the second dividing hole 112 and the adhesive 3 from reaching the second end 11B of the fiber hole 11 or its vicinity.
  • the axial direction of the optical fiber 2 at the tip 2C of the optical fiber 2 located on the second end 11B side of the fiber hole 11 is inclined with respect to the axial direction of the fiber hole 11 due to shrinkage of the adhesive 3 during curing. Can be suppressed. Therefore, the inclination of the tip portion 2C of the optical fiber 2 due to the shrinkage of the adhesive 3 can be suppressed, and the decrease in the coupling efficiency of the optical signal between the optical fiber 2 and other optical components can be suppressed.
  • the misalignment of the tip portion 2C of the optical fiber 2 with respect to the lens portion 20 can be suppressed or prevented.
  • the transmission loss of the optical signal due to the misalignment of the tip portion 2C of the optical fiber 2 with respect to the lens portion 20 can be suppressed.
  • the second end 11B of the fiber hole 11 opens to the front end surface 10B of the ferrule main body 10, and the rear end surface 21A of the lens portion 20 is the front end of the ferrule main body 10. They are arranged at intervals with respect to the surface 10B. Therefore, when manufacturing the ferrule 1, the flatness of the rear end surface 21A of the lens portion 20 to which the tip end portion 2C of the bare portion 2A abuts can be easily ensured. This effect is particularly useful when the ferrule body 10 and the lens portion 20 are integrally formed.
  • the intermediate cavity portion 13 is open to the outside of the ferrule 1. Therefore, the adhesive 3 that has reached the intermediate cavity 13 can be discharged to the outside of the ferrule 1. As a result, it is possible to more reliably prevent the adhesive 3 that has entered the fiber hole 11 from the first end 11A of the fiber hole 11 from reaching the second end 11B of the fiber hole 11 or its vicinity.
  • the length L11 of the first dividing hole 111 in which the adhesive 3 easily enters the gap with the optical fiber 2 is located in front of the intermediate cavity portion 13.
  • the length of 112 is shorter than L12. Therefore, the force acting on the optical fiber 2 due to the shrinkage of the adhesive 3 that has entered the fiber hole 11 can be suppressed to a smaller size. As a result, the inclination of the tip portion 2C of the optical fiber 2 due to the shrinkage of the adhesive 3 can be further suppressed.
  • the length L1 of the fiber hole 11 is longer than the length L2 of the adhesive filling portion 12. Therefore, the amount of the adhesive 3 filled in the adhesive filling portion 12 can be suppressed to be smaller than in the case where the length L1 of the fiber hole 11 is equal to or less than the length L2 of the adhesive filling portion 12. .. As a result, the amount of shrinkage of the adhesive 3 at the time of curing can be suppressed to a small size. As a result, the inclination of the tip portion 2C of the optical fiber 2 due to the shrinkage of the adhesive 3 can be further suppressed.
  • the length L1 of the fiber hole 11 it is possible to suppress the inclination angle at which the axial direction of the optical fiber 2 is inclined with respect to the axial direction of the fiber hole 11 in the fiber hole 11 to be small. From the above, it is possible to further suppress a decrease in the coupling efficiency of the optical signal.
  • the intermediate cavity portion 13 opens to the outside. Therefore, even if the length L1 of the fiber hole 11 is long, the ferrule 1 can be manufactured only by resin molding. This point will be described in more detail below.
  • the mold for resin-molding the ferrule 1 requires an elongated pin for forming the fiber hole 11.
  • the elongated pin is easily bent, it is difficult to accurately form the fiber hole 11.
  • the mold by providing the mold with a support portion that supports the intermediate portion in the longitudinal direction of the elongated pin, it is possible to prevent the elongated pin from bending.
  • the intermediate cavity portion 13 is opened to the outside by the support portion of the mold. Is formed to do.
  • the optical connector 100 of the present embodiment is filled with the ferrule 1, the optical fiber 2 including the bare portion 2A inserted in the fiber hole 11, and the adhesive filling portion 12 to fix the optical fiber 2 to the ferrule 1.
  • the adhesive 3 and the adhesive 3 are provided.
  • the method for manufacturing the optical connector of the present embodiment includes an insertion step of inserting the bare portion 2A into the fiber hole 11, a filling step of filling the adhesive filling portion 12 with the adhesive 3, and curing the adhesive 3. It has a fixing step of fixing the optical fiber 2 to the ferrule 1.
  • ferrule body 10 and the lens portion 20 may be formed separately and then fixed to each other.
  • the ferrule 1 may not include, for example, the lens portion 20, and may be composed only of the ferrule main body 10 including the fiber hole 11, the adhesive filling portion 12, and the intermediate cavity portion 13 as illustrated in FIGS. 6 and 7.
  • the intermediate cavity portion 13 does not have to open to the outside.
  • the ferrule 1 (particularly the ferrule body 10) may be manufactured, for example, by joining two resin-molded divided bodies to each other. That is, by joining the two divided bodies, the fiber hole 11 and the intermediate cavity portion 13 may be formed inside the ferrule.
  • the above-mentioned method for manufacturing an optical connector may include at least an insertion step, a filling step, and a fixing step, and may not include, for example, a boot insertion step.

Abstract

A ferrule according to the present invention is provided with a ferrule body in which a fiber hole is formed. An adhesive filling section, for filling with an adhesive, and an intermediate cavity section are formed in the ferrule body. The adhesive filling section and the intermediate cavity section communicate with the fiber hole, and in a cross section orthogonal to a longitudinal direction of the fiber hole, the cross-sectional area of the intermediate cavity section is larger than the cross-sectional area of the fiber hole. In the longitudinal direction, the intermediate cavity section is positioned at the middle of the fiber hole.

Description

フェルール、光コネクタ及び光コネクタの製造方法How to manufacture ferrules, optical connectors and optical connectors
　本発明は、フェルール、光コネクタ及び光コネクタの製造方法に関する。
　本願は、２０１９年１０月１日に、日本に出願された特願２０１９－１８１３１３号に基づき優先権を主張し、その内容をここに援用する。 The present invention relates to a ferrule, an optical connector, and a method for manufacturing an optical connector.
The present application claims priority based on Japanese Patent Application No. 2019-181313 filed in Japan on October 1, 2019, the contents of which are incorporated herein by reference.
　特許文献１には、光ファイバの端部を保持するフェルールが開示されている。フェルールは、光ファイバのベア部を挿入するためのファイバ穴と、ファイバ穴の長手方向の第一端に連ねて形成された接着剤充填部と、を有する。光ファイバの端部をフェルールに取り付ける際には、光ファイバのベア部をファイバ穴の第一端からファイバ穴に挿入し、ファイバ穴の長手方向の第二端に到達させる。その後、接着剤を接着剤充填部に充填し、接着剤が硬化することで光ファイバがフェルールに固定される。 Patent Document 1 discloses a ferrule that holds an end portion of an optical fiber. The ferrule has a fiber hole for inserting a bare portion of an optical fiber and an adhesive filling portion formed so as to be connected to the first end in the longitudinal direction of the fiber hole. When attaching the end of the optical fiber to the ferrule, the bare portion of the optical fiber is inserted into the fiber hole from the first end of the fiber hole to reach the second end in the longitudinal direction of the fiber hole. After that, the adhesive is filled in the adhesive filling portion, and the adhesive is cured to fix the optical fiber to the ferrule.
日本国特開２０１８－０９２１５２号公報Japanese Patent Application Laid-Open No. 2018-092152
　この種のフェルールでは、接着剤充填部に充填された接着剤が、ファイバ穴とこれに挿入された光ファイバとの隙間を通してファイバ穴の第二端又はその近くに到達する場合がある。このため、接着剤が硬化時に収縮することにより、ファイバ穴の第二端側に位置する光ファイバの先端部が側方から力を受けて、光ファイバの先端部における光ファイバの軸方向がファイバ穴の軸方向に対して傾斜することがある。この場合、例えば、コネクタ同士の光信号の結合効率が低下する、という問題がある。 In this type of ferrule, the adhesive filled in the adhesive filling portion may reach or near the second end of the fiber hole through the gap between the fiber hole and the optical fiber inserted therein. Therefore, as the adhesive shrinks during curing, the tip of the optical fiber located on the second end side of the fiber hole receives a force from the side, and the axial direction of the optical fiber at the tip of the optical fiber is fiber. It may tilt with respect to the axial direction of the hole. In this case, for example, there is a problem that the coupling efficiency of optical signals between connectors is lowered.
　本発明は、上述した事情に鑑みてなされたものであって、ファイバ穴の内部において光ファイバの先端部の傾斜を抑えることが可能なフェルール、これを備える光コネクタ及び光コネクタの製造方法を提供することを目的とする。 The present invention has been made in view of the above circumstances, and provides a ferrule capable of suppressing the inclination of the tip of an optical fiber inside a fiber hole, an optical connector provided with the ferrule, and a method for manufacturing the optical connector. The purpose is to do.
　本発明の一態様に係るフェルールは、光ファイバのベア部が挿入されるファイバ穴を有するフェルールであって、前記ファイバ穴が形成されたフェルール本体を備え、前記フェルール本体には、接着剤を充填するための接着剤充填部と、中間空洞部と、が形成され、前記接着剤充填部および前記中間空洞部は前記ファイバ穴に連通し、前記ファイバ穴の長手方向に直交する断面において、前記中間空洞部の断面積は前記ファイバ穴の断面積より大きく、前記長手方向において、前記中間空洞部は前記ファイバ穴の中間に位置する。 The ferrule according to one aspect of the present invention is a ferrule having a fiber hole into which a bare portion of an optical fiber is inserted, includes a ferrule body in which the fiber hole is formed, and the ferrule body is filled with an adhesive. An adhesive filling portion and an intermediate cavity portion are formed, and the adhesive filling portion and the intermediate cavity portion communicate with the fiber hole, and in a cross section orthogonal to the longitudinal direction of the fiber hole, the intermediate portion is formed. The cross-sectional area of the cavity is larger than the cross-sectional area of the fiber hole, and the intermediate cavity is located in the middle of the fiber hole in the longitudinal direction.
　上記のフェルールでは、接着剤充填部に充填された接着剤が、ファイバ穴と光ファイバとの隙間に入り込んでファイバ穴内を毛管力などにより進んでも、当該接着剤は中間空洞部においてファイバ穴の外側に排出される。このため、接着剤がファイバ穴の第二端やその近くに到達することを抑制又は防止できる。これにより、光ファイバの先端部における光ファイバの軸方向が、接着剤の硬化時における収縮によってファイバ穴の軸方向に対して傾斜することを抑制できる。 In the above ferrule, even if the adhesive filled in the adhesive filling portion enters the gap between the fiber hole and the optical fiber and advances in the fiber hole due to capillary force or the like, the adhesive stays outside the fiber hole in the intermediate cavity portion. Is discharged to. Therefore, it is possible to prevent or prevent the adhesive from reaching the second end of the fiber hole or its vicinity. As a result, it is possible to prevent the axial direction of the optical fiber at the tip of the optical fiber from being inclined with respect to the axial direction of the fiber hole due to shrinkage during curing of the adhesive.
　上記フェルールにおいては、前記中間空洞部が前記フェルール本体の外側に開口してもよい。 In the ferrule, the intermediate cavity may open to the outside of the ferrule body.
　上記フェルールにおいては、前記ファイバ穴が、前記中間空洞部により、前記長手方向において前記接着剤充填部側から順番に並ぶ第一分割穴と第二分割穴とに分断され、前記長手方向における前記第二分割穴の長さが、前記長手方向における前記第一分割穴の長さよりも長くてもよい。 In the ferrule, the fiber hole is divided into a first division hole and a second division hole which are arranged in order from the adhesive filling portion side in the longitudinal direction by the intermediate cavity portion, and the first division hole in the longitudinal direction. The length of the bipartition hole may be longer than the length of the first division hole in the longitudinal direction.
　上記フェルールにおいては、前記長手方向における前記ファイバ穴の長さが、前記長手方向における前記接着剤充填部の長さよりも長くてもよい。 In the ferrule, the length of the fiber hole in the longitudinal direction may be longer than the length of the adhesive filling portion in the longitudinal direction.
　上記フェルールは、前記接着剤充填部とは反対側の前記ファイバ穴の端部に対向するレンズ部をさらに備えてもよい。 The ferrule may further include a lens portion facing the end of the fiber hole on the opposite side of the adhesive filling portion.
　上記フェルールにおいては、前記ファイバ穴が前記フェルール本体の前端面に開口し、前記レンズ部の後端面が、前記長手方向において前記フェルール本体の前記前端面に対向し、かつ前記前端面に対して間隔をあけて配されてもよい。 In the ferrule, the fiber hole opens in the front end surface of the ferrule body, and the rear end surface of the lens portion faces the front end surface of the ferrule body in the longitudinal direction and is spaced from the front end surface. May be arranged with an opening.
　本発明の一態様に係る光コネクタは、前記フェルールと、前記ファイバ穴に挿入されたベア部を含む光ファイバと、前記接着剤充填部に充填されて前記光ファイバを前記フェルールに固定する接着剤と、を備える。 The optical connector according to one aspect of the present invention includes the ferrule, an optical fiber including a bare portion inserted into the fiber hole, and an adhesive filled in the adhesive filling portion to fix the optical fiber to the ferrule. And.
　本発明の一態様に係る光コネクタの製造方法は、ベア部を含む光ファイバを前記フェルールに取り付けて光コネクタを製造する光コネクタの製造方法であって、前記ベア部を前記ファイバ穴に挿入し、前記接着剤充填部に接着剤を充填し、前記接着剤を硬化させることで前記光ファイバを前記フェルールに固定する。 The method for manufacturing an optical connector according to one aspect of the present invention is a method for manufacturing an optical connector in which an optical fiber including a bare portion is attached to the ferrule to manufacture an optical connector, and the bare portion is inserted into the fiber hole. The optical fiber is fixed to the ferrule by filling the adhesive filling portion with an adhesive and curing the adhesive.
　上記態様によれば、接着剤の収縮に基づく光ファイバの先端部の傾斜を抑えることができる。 According to the above aspect, the inclination of the tip of the optical fiber due to the shrinkage of the adhesive can be suppressed.
一実施形態に係るフェルールを示す斜視図である。It is a perspective view which shows the ferrule which concerns on one Embodiment. 図１のフェルールを別の角度から見た斜視図である。It is a perspective view which looked at the ferrule of FIG. 1 from another angle. 図１，２のIII－III矢視断面図である。It is a cross-sectional view taken along the line III-III of FIGS. 図３のIV－IV矢視断面図である。FIG. 3 is a cross-sectional view taken along the line IV-IV of FIG. 図１～４のフェルールに光ファイバを取り付けた状態を示す断面図である。It is sectional drawing which shows the state which attached the optical fiber to the ferrule of FIGS. 1 to 4. 他の実施形態に係るフェルールを示す斜視図である。It is a perspective view which shows the ferrule which concerns on other embodiment. 図６のVII－VII矢視断面図である。FIG. 6 is a cross-sectional view taken along the line VII-VII of FIG.
　以下、フェルールの一実施形態について、図１～５を参照して説明する。図１～４に示すように、本実施形態のフェルール１は、フェルール本体１０と、レンズ部２０と、を備える。フェルール１は、光ファイバ２（図５参照）の先端部に取り付けられて、当該光ファイバ２を他の光学部品（例えば光ファイバ、光導波路など）に光学的に結合するために用いられる。フェルール１及び光ファイバ２を合わせて、「光コネクタ」ともいう。 Hereinafter, one embodiment of the ferrule will be described with reference to FIGS. 1 to 5. As shown in FIGS. 1 to 4, the ferrule 1 of the present embodiment includes a ferrule main body 10 and a lens unit 20. The ferrule 1 is attached to the tip of an optical fiber 2 (see FIG. 5) and is used to optically couple the optical fiber 2 to another optical component (eg, optical fiber, optical waveguide, etc.). The ferrule 1 and the optical fiber 2 are collectively referred to as an "optical connector".
　光ファイバ２は、ベア部２Ａ及び被覆部２Ｂを有している（図５参照）。ベア部２Ａは、不図示のコア及びクラッドを有しており、ガラス等によって形成されている。被覆部２Ｂは、ベア部２Ａを被覆しており、樹脂等によって形成されている。光ファイバ２の先端部には被覆部２Ｂが設けられておらず、ベア部２Ａが露出している。 The optical fiber 2 has a bare portion 2A and a covering portion 2B (see FIG. 5). The bare portion 2A has a core and a clad (not shown), and is formed of glass or the like. The covering portion 2B covers the bare portion 2A and is formed of a resin or the like. The covering portion 2B is not provided at the tip end portion of the optical fiber 2, and the bare portion 2A is exposed.
　図３，４に示すように、フェルール本体１０は、ファイバ穴１１と、接着剤充填部１２と、中間空洞部１３と、を有する。以下、ファイバ穴１１の長手方向（Ｘ軸方向）を、単に長手方向という場合がある。Ｘ軸の矢印の先端側を「前側」、その反対側を「後側」という場合がある。図５に示すように、フェルール１は光コネクタの前側の端部に位置し、光ファイバはフェルール１から後側に延出する。
　ファイバ穴１１には、光ファイバ２のベア部２Ａが挿入される。接着剤充填部１２には、接着剤３（図５参照）が充填される。中間空洞部１３は、長手方向（Ｘ軸方向）におけるファイバ穴１１の中間部に形成されている。また、本実施形態のフェルール本体１０は、ブーツ収納部１４をさらに有する。 As shown in FIGS. 3 and 4, the ferrule body 10 has a fiber hole 11, an adhesive filling portion 12, and an intermediate cavity portion 13. Hereinafter, the longitudinal direction (X-axis direction) of the fiber hole 11 may be simply referred to as the longitudinal direction. The tip side of the X-axis arrow may be referred to as the "front side", and the opposite side may be referred to as the "rear side". As shown in FIG. 5, the ferrule 1 is located at the front end of the optical connector, and the optical fiber extends from the ferrule 1 to the rear.
The bare portion 2A of the optical fiber 2 is inserted into the fiber hole 11. The adhesive filling portion 12 is filled with the adhesive 3 (see FIG. 5). The intermediate cavity portion 13 is formed in the intermediate portion of the fiber hole 11 in the longitudinal direction (X-axis direction). Further, the ferrule body 10 of the present embodiment further has a boot storage portion 14.
　ファイバ穴１１は、一つの光ファイバ２のベア部２Ａを挿入可能なように直線状に形成されている。ファイバ穴１１の内径寸法は、ベア部２Ａの外径寸法よりも微小に大きい。このため、ベア部２Ａをファイバ穴１１に挿入した状態では、ファイバ穴１１の内周とベア部２Ａの外周との間には隙間が生じる。これにより、ファイバ穴１１に挿入されたベア部２Ａをファイバ穴１１の長手方向に進めることができる。 The fiber hole 11 is formed in a straight line so that the bare portion 2A of one optical fiber 2 can be inserted. The inner diameter of the fiber hole 11 is slightly larger than the outer diameter of the bare portion 2A. Therefore, when the bare portion 2A is inserted into the fiber hole 11, a gap is generated between the inner circumference of the fiber hole 11 and the outer circumference of the bare portion 2A. As a result, the bare portion 2A inserted into the fiber hole 11 can be advanced in the longitudinal direction of the fiber hole 11.
　ファイバ穴１１は、第一端１１Ａと、第二端１１Ｂと、を有する。第一端１１Ａは、光ファイバ２をファイバ穴１１内に挿入する際の入り口となる端部である。接着剤充填部１２は、第一端１１Ａよりも後側に位置している。第二端１１Ｂは、第一端１１Ａとは反対側のファイバ穴１１の端部である。第一端１１Ａには、ベア部２Ａをファイバ穴１１に案内するための案内部１５が連ねて形成されている。案内部１５は、ファイバ穴１１の長手方向においてファイバ穴１１と接着剤充填部１２との間に位置する。案内部１５はファイバ穴１１の長手方向に沿って延びる穴である。案内部１５の内径寸法はファイバ穴１１の内径寸法よりも大きい。案内部１５と第一端１１Ａとの接続部には、傾斜面が設けられている。これにより、ベア部２Ａを案内部１５に入れるだけで、ベア部２Ａを第一端１１Ａからファイバ穴１１に簡単に挿入することができる。 The fiber hole 11 has a first end 11A and a second end 11B. The first end 11A is an end portion that serves as an entrance when the optical fiber 2 is inserted into the fiber hole 11. The adhesive filling portion 12 is located behind the first end 11A. The second end 11B is the end of the fiber hole 11 on the side opposite to the first end 11A. The first end 11A is formed with a series of guide portions 15 for guiding the bare portion 2A to the fiber hole 11. The guide portion 15 is located between the fiber hole 11 and the adhesive filling portion 12 in the longitudinal direction of the fiber hole 11. The guide portion 15 is a hole extending along the longitudinal direction of the fiber hole 11. The inner diameter of the guide portion 15 is larger than the inner diameter of the fiber hole 11. An inclined surface is provided at the connecting portion between the guide portion 15 and the first end 11A. As a result, the bare portion 2A can be easily inserted into the fiber hole 11 from the first end 11A simply by inserting the bare portion 2A into the guide portion 15.
　本実施形態におけるファイバ穴１１の第二端１１Ｂは、フェルール本体１０の前端面１０Ｂに開口している。前端面１０Ｂは、長手方向においてレンズ部２０に対向する。ただし、ファイバ穴１１の第二端１１Ｂは、例えばフェルール本体１０の外側に開口しなくてもよい。 The second end 11B of the fiber hole 11 in the present embodiment is open to the front end surface 10B of the ferrule body 10. The front end surface 10B faces the lens portion 20 in the longitudinal direction. However, the second end 11B of the fiber hole 11 does not have to be opened to the outside of the ferrule body 10, for example.
　ファイバ穴１１は、中間空洞部１３により第一分割穴１１１と第二分割穴１１２とに分断されている。第一分割穴１１１と第二分割穴１１２とは、ファイバ穴１１の長手方向において後述する接着剤充填部１２側から順番に並ぶ。つまり、第一分割穴１１１は第二分割穴１１２よりも後側に位置する。長手方向における第二分割穴１１２の長さＬ１２は、第一分割穴１１１の長さＬ１１よりも長い。 The fiber hole 11 is divided into a first dividing hole 111 and a second dividing hole 112 by an intermediate cavity portion 13. The first dividing hole 111 and the second dividing hole 112 are arranged in order from the adhesive filling portion 12 side, which will be described later, in the longitudinal direction of the fiber hole 11. That is, the first dividing hole 111 is located behind the second dividing hole 112. The length L12 of the second dividing hole 112 in the longitudinal direction is longer than the length L11 of the first dividing hole 111.
　ファイバ穴１１の数は例えば一つであってもよい。本実施形態におけるファイバ穴１１の数は複数（図４では１２個）である。複数のファイバ穴１１は、その長手方向に直交する方向（Ｙ軸方向）に間隔をあけて並んでいる。これにより、本実施形態のフェルール１では、複数本の光ファイバ２を一括して保持することができる。
　前述した案内部１５は、複数のファイバ穴１１に対してそれぞれ形成されている。すなわち、案内部１５の数はファイバ穴１１の数と同じである。 The number of fiber holes 11 may be one, for example. The number of fiber holes 11 in this embodiment is a plurality (12 in FIG. 4). The plurality of fiber holes 11 are arranged at intervals in a direction (Y-axis direction) orthogonal to the longitudinal direction thereof. As a result, in the ferrule 1 of the present embodiment, a plurality of optical fibers 2 can be collectively held.
The guide portion 15 described above is formed for each of the plurality of fiber holes 11. That is, the number of guide portions 15 is the same as the number of fiber holes 11.
　フェルールの前後方向は、ファイバ穴１１の長手方向（Ｘ軸方向）に対応している。また、前後方向において、ファイバ穴１１の第一端１１Ａ側を後側と呼び、ファイバ穴１１の第二端１１Ｂ側を前側と呼ぶことがある。また、フェルール１の幅方向は、複数のファイバ穴１１の配列方向（Ｙ軸方向）に対応している。また、前後方向及び幅方向の両方に直交する方向（Ｚ軸方向）を、上下方向と呼ぶことがある。 The front-back direction of the ferrule corresponds to the longitudinal direction (X-axis direction) of the fiber hole 11. Further, in the front-rear direction, the first end 11A side of the fiber hole 11 may be referred to as the rear side, and the second end 11B side of the fiber hole 11 may be referred to as the front side. Further, the width direction of the ferrule 1 corresponds to the arrangement direction (Y-axis direction) of the plurality of fiber holes 11. Further, a direction (Z-axis direction) orthogonal to both the front-rear direction and the width direction may be referred to as a vertical direction.
　接着剤充填部１２は、接着剤３を充填するための空洞である。接着剤３は、光ファイバ２（特にベア部２Ａ）をフェルール１に固定するために用いられる。
　接着剤充填部１２は、ファイバ穴１１の第一端１１Ａ側（後側）に形成されている。本実施形態の接着剤充填部１２は、案内部１５を介してファイバ穴１１の第一端１１Ａに連通している。ただし、接着剤充填部１２は、例えばファイバ穴１１の第一端１１Ａに直接つながっていてもよい。また、本実施形態では、同一の接着剤充填部１２が複数のファイバ穴１１に対応している。すなわち、一つの接着剤充填部１２が複数のファイバ穴１１に連通している。 The adhesive filling portion 12 is a cavity for filling the adhesive 3. The adhesive 3 is used to fix the optical fiber 2 (particularly the bare portion 2A) to the ferrule 1.
The adhesive filling portion 12 is formed on the first end 11A side (rear side) of the fiber hole 11. The adhesive filling portion 12 of the present embodiment communicates with the first end 11A of the fiber hole 11 via the guide portion 15. However, the adhesive filling portion 12 may be directly connected to, for example, the first end 11A of the fiber hole 11. Further, in the present embodiment, the same adhesive filling portion 12 corresponds to a plurality of fiber holes 11. That is, one adhesive filling portion 12 communicates with a plurality of fiber holes 11.
　図１～４に示すように、接着剤充填部１２は、フェルール本体１０の外側に開口している。接着剤充填部１２が開口する方向や接着剤充填部１２の開口の数は、任意であってよい。本実施形態の接着剤充填部１２は、フェルール本体１０の上下方向に開口している。接着剤充填部１２の上側の開口１２Ａは、例えば接着剤３を注入する注入口として機能する。接着剤充填部１２の下側の開口１２Ｂは、例えば接着剤充填部１２とフェルール本体１０の外部との間で通気させる通気口として機能する。 As shown in FIGS. 1 to 4, the adhesive filling portion 12 is open to the outside of the ferrule body 10. The direction in which the adhesive filling portion 12 opens and the number of openings in the adhesive filling portion 12 may be arbitrary. The adhesive filling portion 12 of the present embodiment is open in the vertical direction of the ferrule body 10. The upper opening 12A of the adhesive filling portion 12 functions as, for example, an injection port for injecting the adhesive 3. The lower opening 12B of the adhesive filling portion 12 functions as, for example, a vent for ventilation between the adhesive filling portion 12 and the outside of the ferrule body 10.
　図２～４に示すブーツ収納部１４は、ブーツ４（図５参照）を収納するための空洞である。ブーツ収納部１４は、接着剤充填部１２の後側に連ねて形成されている。ブーツ収納部１４は、フェルール本体１０のうち、前端面１０Ｂとは反対側に向く後端面１０Ａに開口する。図３，４においては、仮想線ＢＬが接着剤充填部１２とブーツ収納部１４との境界を示している。すなわち、仮想線ＢＬよりも後側がブーツ収納部１４であり、仮想線ＢＬよりも前側が接着剤充填部１２である。 The boot storage unit 14 shown in FIGS. 2 to 4 is a cavity for storing the boot 4 (see FIG. 5). The boot storage portion 14 is formed so as to be connected to the rear side of the adhesive filling portion 12. The boot storage portion 14 opens to the rear end surface 10A of the ferrule body 10 facing the side opposite to the front end surface 10B. In FIGS. 3 and 4, the virtual line BL indicates the boundary between the adhesive filling portion 12 and the boot storage portion 14. That is, the boot storage portion 14 is on the rear side of the virtual line BL, and the adhesive filling portion 12 is on the front side of the virtual line BL.
　図５に示すように、ブーツ４は、光ファイバ２を通す挿通孔４Ａを有する筒状に形成されている。ブーツ４は、ゴム等の弾性体により形成されている。光ファイバ２が挿通されたブーツ４を、フェルール本体１０の後端面１０Ａ側からブーツ収納部１４に挿入した状態では、ブーツ収納部１４全体がブーツ４で埋められる。また、この状態では、ブーツ４の外周がブーツ収納部１４の内周に密着する。 As shown in FIG. 5, the boot 4 is formed in a tubular shape having an insertion hole 4A through which the optical fiber 2 is passed. The boot 4 is formed of an elastic body such as rubber. When the boot 4 through which the optical fiber 2 is inserted is inserted into the boot storage portion 14 from the rear end surface 10A side of the ferrule main body 10, the entire boot storage portion 14 is filled with the boot 4. Further, in this state, the outer circumference of the boot 4 is in close contact with the inner circumference of the boot storage portion 14.
　図３，４に示すように、中間空洞部１３は、フェルール本体１０の前後方向（ファイバ穴１１の長手方向）に直交する断面でファイバ穴１１の断面積よりも大きな断面積を有する。言い換えれば、前後方向におけるファイバ穴１１の中間部では、ファイバ穴１１の内径寸法が中間空洞部１３によって拡げられている。本実施形態では、同一の中間空洞部１３が複数のファイバ穴１１に対応している。すなわち、一つの中間空洞部１３が複数のファイバ穴１１に連通している。中間空洞部１３の幅方向の寸法は、幅方向に配列された複数のファイバ穴１１のうち、幅方向の両端に配された二つのファイバ穴１１の間の長さよりもよりも長い。 As shown in FIGS. 3 and 4, the intermediate cavity portion 13 has a cross-sectional area orthogonal to the front-rear direction (longitudinal direction of the fiber hole 11) of the ferrule body 10 and a cross-sectional area larger than the cross-sectional area of the fiber hole 11. In other words, in the intermediate portion of the fiber hole 11 in the front-rear direction, the inner diameter dimension of the fiber hole 11 is expanded by the intermediate cavity portion 13. In this embodiment, the same intermediate cavity portion 13 corresponds to a plurality of fiber holes 11. That is, one intermediate cavity portion 13 communicates with a plurality of fiber holes 11. The widthwise dimension of the intermediate cavity 13 is longer than the length between the two fiber holes 11 arranged at both ends in the width direction among the plurality of fiber holes 11 arranged in the width direction.
　図１～３に示すように、中間空洞部１３は、フェルール本体１０の外側に開口している。中間空洞部１３が開口する方向や中間空洞部１３の開口の数は、任意であってよい。本実施形態の中間空洞部１３は、フェルール本体１０の上下に開口している。すなわち、中間空洞部１３は上側の開口１３Ａ及び下側の開口１３Ｂを有する。 As shown in FIGS. 1 to 3, the intermediate cavity portion 13 is open to the outside of the ferrule body 10. The direction in which the intermediate cavity 13 opens and the number of openings in the intermediate cavity 13 may be arbitrary. The intermediate cavity portion 13 of the present embodiment is open at the top and bottom of the ferrule body 10. That is, the intermediate cavity portion 13 has an upper opening 13A and a lower opening 13B.
　以上のように構成されるフェルール本体１０においては、図３に示すように、フェルール本体１０の前後方向におけるファイバ穴１１の長さＬ１が、接着剤充填部１２の長さＬ２よりも長い。ファイバ穴１１の長さＬ１は、その第一端１１Ａから第二端１１Ｂに至る長さである。一方、接着剤充填部１２の長さＬ２は、接着剤充填部１２のうち案内部１５が開口する面からブーツ収納部１４との境界（仮想線ＢＬ）に至る長さである。なお、案内部１５が設けられていない場合、接着剤充填部１２の長さＬ２は、接着剤充填部１２のうちファイバ穴１１が開口する面からブーツ収納部１４との境界に至る長さである。 In the ferrule body 10 configured as described above, as shown in FIG. 3, the length L1 of the fiber hole 11 in the front-rear direction of the ferrule body 10 is longer than the length L2 of the adhesive filling portion 12. The length L1 of the fiber hole 11 is the length from the first end 11A to the second end 11B. On the other hand, the length L2 of the adhesive filling portion 12 is the length from the surface of the adhesive filling portion 12 where the guide portion 15 opens to the boundary (virtual line BL) with the boot storage portion 14. When the guide portion 15 is not provided, the length L2 of the adhesive filling portion 12 is the length from the surface of the adhesive filling portion 12 where the fiber hole 11 opens to the boundary with the boot storage portion 14. is there.
　レンズ部２０は、光信号を透過可能な材料からなる。本実施形態のレンズ部２０は透明樹脂からなる。レンズ部２０の材料は、例えばスーパーエンジニアリングプラスチックであってよい。図１，３，４に示すように、レンズ部２０は、板状部２１と、複数のレンズ本体２２と、を有する。板状部２１は、上下方向および幅方向に延びる板状であり、フェルール本体１０と一体に形成されている。板状部２１の前端面２１Ｂには、後側に向けて窪む凹部２３が形成されている。凹部２３は前側から見て長方形状である。レンズ本体２２は板状部２１と一体に形成されており、凹部２３の内側に位置している。 The lens unit 20 is made of a material capable of transmitting an optical signal. The lens portion 20 of this embodiment is made of a transparent resin. The material of the lens portion 20 may be, for example, super engineering plastic. As shown in FIGS. 1, 3 and 4, the lens portion 20 includes a plate-shaped portion 21 and a plurality of lens main bodies 22. The plate-shaped portion 21 has a plate-like shape extending in the vertical direction and the width direction, and is integrally formed with the ferrule main body 10. The front end surface 21B of the plate-shaped portion 21 is formed with a recess 23 that is recessed toward the rear side. The recess 23 has a rectangular shape when viewed from the front side. The lens body 22 is integrally formed with the plate-shaped portion 21, and is located inside the recess 23.
　レンズ部２０は、前後方向においてファイバ穴１１の第二端１１Ｂに対向する。具体的に、レンズ部２０は、板状部２１の後端面２１Ａがフェルール本体１０の前端面１０Ｂ（特にファイバ穴１１の第二端１１Ｂが開口する領域）に対向するように配される。板状部２１の後端面２１Ａは、例えばフェルール本体１０の前端面１０Ｂに接触してもよいが、本実施形態ではフェルール本体１０の前端面１０Ｂに対して間隔をあけて配される。 The lens portion 20 faces the second end 11B of the fiber hole 11 in the front-rear direction. Specifically, the lens portion 20 is arranged so that the rear end surface 21A of the plate-shaped portion 21 faces the front end surface 10B of the ferrule body 10 (particularly, the region where the second end 11B of the fiber hole 11 opens). The rear end surface 21A of the plate-shaped portion 21 may come into contact with, for example, the front end surface 10B of the ferrule body 10, but in the present embodiment, the rear end surface 21A is arranged at intervals with respect to the front end surface 10B of the ferrule body 10.
　レンズ本体２２は、ファイバ穴１１（あるいはこれに挿入された光ファイバ２のベア部２Ａ）に対して前後方向に並ぶように位置する。レンズ本体２２は、例えばコリメートレンズとして機能する。すなわち、レンズ本体２２は、例えばフェルール１に対して外側（前側）から入射する光信号を集光した上で光ファイバ２の先端部２Ｃ（図５参照）に入力する。あるいは、レンズ本体２２は、光ファイバ２の先端部２Ｃから出力された光信号のビーム径を拡大した上でフェルール１の外側（前側）に出力する。これにより、他の光学部品と光ファイバ２とを光学的に接続することができる。 The lens body 22 is positioned so as to line up in the front-rear direction with respect to the fiber hole 11 (or the bare portion 2A of the optical fiber 2 inserted therein). The lens body 22 functions as, for example, a collimating lens. That is, for example, the lens body 22 collects an optical signal incident on the ferrule 1 from the outside (front side) and then inputs the optical signal to the tip portion 2C (see FIG. 5) of the optical fiber 2. Alternatively, the lens body 22 enlarges the beam diameter of the optical signal output from the tip portion 2C of the optical fiber 2 and then outputs the light signal to the outside (front side) of the ferrule 1. As a result, the optical fiber 2 can be optically connected to other optical components.
　本実施形態において、各レンズ本体２２は、板状部２１の前端面２１Ｂ側に形成された凸レンズである。また、複数のレンズ本体２２は、複数のファイバ穴１１に各々対応するように幅方向に複数並んでいる。
　さらに、本実施形態のレンズ本体２２は、板状部２１の前端面２１Ｂから窪む凹部２３の底部に位置する。これにより、他の光学部品（例えば他のフェルール）が前端面２１Ｂに突き当てられた際に、レンズ本体２２が他の光学部品に接触してレンズ本体２２に傷がつくことなどを防止できる。 In the present embodiment, each lens body 22 is a convex lens formed on the front end surface 21B side of the plate-shaped portion 21. Further, a plurality of lens main bodies 22 are arranged in the width direction so as to correspond to the plurality of fiber holes 11.
Further, the lens body 22 of the present embodiment is located at the bottom of the recess 23 recessed from the front end surface 21B of the plate-shaped portion 21. As a result, when another optical component (for example, another ferrule) is abutted against the front end surface 21B, it is possible to prevent the lens body 22 from coming into contact with the other optical component and damaging the lens body 22.
　本実施形態では、上記したフェルール本体１０及びレンズ部２０が一体に形成されている。このため、フェルール本体１０は、レンズ部２０と同様に光信号を透過可能な材料からなる。図１，３，４に示すように、本実施形態では、フェルール本体１０とレンズ部２０とが幅方向の両端部において互いに接続されている。ただし、フェルール本体１０とレンズ部２０とは幅方向の両端部において接続されていなくてもよい。 In the present embodiment, the ferrule body 10 and the lens portion 20 described above are integrally formed. Therefore, the ferrule body 10 is made of a material capable of transmitting an optical signal like the lens portion 20. As shown in FIGS. 1, 3 and 4, in the present embodiment, the ferrule body 10 and the lens portion 20 are connected to each other at both ends in the width direction. However, the ferrule body 10 and the lens portion 20 may not be connected at both ends in the width direction.
　図１，２，４に示すように、本実施形態のフェルール１は、当該フェルール１を他の光学部品（例えば他のフェルール）と位置合わせするための一対のガイド穴３０をさらに有する。ガイド穴３０は、少なくとも前後方向に延び、フェルール１（レンズ部２０）の前端面２１Ｂに開口していればよい。本実施形態のガイド穴３０は、フェルール１（フェルール本体１０）の後端面１０Ａにも開口する。すなわち、ガイド穴３０はフェルール１を前後方向に貫通している。また、本実施形態の一対のガイド穴３０は、幅方向における複数のファイバ穴１１の両側に形成されている。
　フェルール１のガイド穴３０、及び、他の光学部品のガイド穴にガイドピン（不図示）が挿入されることで、フェルール１と他の光学部品とを位置合わせできる。ガイドピンは、フェルール１に固定されてもよいし、他の光学部品に固定されてもよい。 As shown in FIGS. 1, 2 and 4, the ferrule 1 of the present embodiment further has a pair of guide holes 30 for aligning the ferrule 1 with another optical component (for example, another ferrule). The guide hole 30 may extend at least in the front-rear direction and may open to the front end surface 21B of the ferrule 1 (lens portion 20). The guide hole 30 of the present embodiment also opens to the rear end surface 10A of the ferrule 1 (ferrule main body 10). That is, the guide hole 30 penetrates the ferrule 1 in the front-rear direction. Further, the pair of guide holes 30 of the present embodiment are formed on both sides of the plurality of fiber holes 11 in the width direction.
By inserting a guide pin (not shown) into the guide hole 30 of the ferrule 1 and the guide hole of another optical component, the ferrule 1 and the other optical component can be aligned. The guide pin may be fixed to the ferrule 1 or may be fixed to another optical component.
　次に、本実施形態のフェルール１に光ファイバ２を取り付ける方法、すなわち、図５に示すようにフェルール１に光ファイバ２を取り付けた光コネクタ１００を製造する製造方法の一例について説明する。
　フェルール１に光ファイバ２を取り付ける際には、はじめに、ブーツ４の挿通孔４Ａに光ファイバ２を通すブーツ挿通工程を実施する。 Next, an example of a method of attaching the optical fiber 2 to the ferrule 1 of the present embodiment, that is, an example of a manufacturing method of manufacturing the optical connector 100 in which the optical fiber 2 is attached to the ferrule 1 as shown in FIG. 5 will be described.
When attaching the optical fiber 2 to the ferrule 1, first, a boot insertion step of passing the optical fiber 2 through the insertion hole 4A of the boot 4 is performed.
　次いで、光ファイバ２のベア部２Ａをファイバ穴１１の第一端１１Ａからファイバ穴１１に挿入する挿入工程を実施する。挿入工程では、ベア部２Ａの先端部２Ｃをファイバ穴１１の第二端１１Ｂに到達させる。
　本実施形態の挿入工程では、ブーツ４から前側に突出する光ファイバ２の部位（特にベア部２Ａ）を、フェルール本体１０の後端面１０Ａからブーツ収納部１４及び接着剤充填部１２に順番に通した後に、ベア部２Ａをファイバ穴１１に挿入する。また、本実施形態の挿入工程では、ベア部２Ａの先端部２Ｃをファイバ穴１１の第二端１１Ｂから突出させてレンズ部２０の後端面２１Ａに突き当てる。また、本実施形態の挿入工程では、上記した光ファイバ２のフェルール本体１０への挿入と同時又は挿入の後に、ブーツ４をフェルール本体１０のブーツ収納部１４に収納する。
　挿入工程後の状態では、光ファイバ２（特にベア部２Ａ）のうちファイバ穴１１の第一端１１Ａから後側に突出する部分が、接着剤充填部１２に位置する。 Next, an insertion step of inserting the bare portion 2A of the optical fiber 2 into the fiber hole 11 from the first end 11A of the fiber hole 11 is carried out. In the insertion step, the tip portion 2C of the bare portion 2A is brought to reach the second end 11B of the fiber hole 11.
In the insertion step of the present embodiment, the portion of the optical fiber 2 (particularly the bare portion 2A) protruding from the boot 4 to the front side is passed through the boot storage portion 14 and the adhesive filling portion 12 in order from the rear end surface 10A of the ferrule body 10. After that, the bare portion 2A is inserted into the fiber hole 11. Further, in the insertion step of the present embodiment, the tip portion 2C of the bare portion 2A is projected from the second end 11B of the fiber hole 11 and abutted against the rear end surface 21A of the lens portion 20. Further, in the insertion step of the present embodiment, the boot 4 is stored in the boot storage portion 14 of the ferrule body 10 at the same time as or after the above-mentioned insertion of the optical fiber 2 into the ferrule body 10.
In the state after the insertion step, the portion of the optical fiber 2 (particularly the bare portion 2A) that protrudes rearward from the first end 11A of the fiber hole 11 is located in the adhesive filling portion 12.
　その後、フェルール本体１０の接着剤充填部１２に接着剤３を充填する充填工程を実施する。本実施形態の充填工程では、接着剤３を接着剤充填部１２の上側の開口１２Ａから注入する。本実施形態の接着剤充填部１２は下側の開口１２Ｂを有するが、接着剤３は自身の粘性や表面張力によって接着剤充填部１２に留まることができる。接着剤充填部１２に注入された接着剤３は、ベア部２Ａと第一分割穴１１１との間の隙間に、毛細管現象などによって入り込むことがある。
　また、接着剤３を上側の開口１２Ａから接着剤充填部１２に注入した際には、接着剤充填部１２にある空気を下側の開口１２Ｂから外側に効率よく逃がすことができる。これにより、接着剤３を接着剤充填部１２に効率よく充填できる。また、接着剤充填部１２に気泡が残ることを抑制又は防止できる。 After that, a filling step of filling the adhesive filling portion 12 of the ferrule body 10 with the adhesive 3 is performed. In the filling step of the present embodiment, the adhesive 3 is injected through the opening 12A on the upper side of the adhesive filling portion 12. The adhesive filling portion 12 of the present embodiment has a lower opening 12B, but the adhesive 3 can stay in the adhesive filling portion 12 due to its own viscosity and surface tension. The adhesive 3 injected into the adhesive filling portion 12 may enter the gap between the bare portion 2A and the first dividing hole 111 due to a capillary phenomenon or the like.
Further, when the adhesive 3 is injected into the adhesive filling portion 12 through the upper opening 12A, the air in the adhesive filling portion 12 can be efficiently released to the outside from the lower opening 12B. As a result, the adhesive 3 can be efficiently filled in the adhesive filling portion 12. In addition, it is possible to suppress or prevent bubbles from remaining in the adhesive filling portion 12.
　最後に、接着剤充填部１２に充填された接着剤３を硬化させることで、光ファイバ２（特にベア部２Ａ）をフェルール１に固定する固定工程を実施する。以上により、光コネクタ１００の製造が完了する。
　なお、上記した光コネクタ１００の製造方法では、例えば屈折率整合剤となる接着剤（不図示）を、フェルール本体１０の前端面１０Ｂとレンズ部２０の後端面２１Ａとの隙間（空洞）に充填してもよい。この工程は、少なくとも光ファイバ２の先端部２Ｃをレンズ部２０の後端面２１Ａに突き当てた後に実施されればよい。 Finally, a fixing step of fixing the optical fiber 2 (particularly the bare portion 2A) to the ferrule 1 is carried out by curing the adhesive 3 filled in the adhesive filling portion 12. As described above, the production of the optical connector 100 is completed.
In the method for manufacturing the optical connector 100 described above, for example, an adhesive (not shown) serving as a refractive index matching agent is filled in the gap (cavity) between the front end surface 10B of the ferrule body 10 and the rear end surface 21A of the lens portion 20. You may. This step may be performed at least after the tip portion 2C of the optical fiber 2 is abutted against the rear end surface 21A of the lens portion 20.
　以上のように製造される本実施形態の光コネクタ１００は、図５に示すように、フェルール１と、光ファイバ２と、接着剤３と、を備える。また、本実施形態の光コネクタ１００は、ブーツ４も含む。
　光コネクタ１００において、光ファイバ２のベア部２Ａは、フェルール１のファイバ穴１１の第一端１１Ａからファイバ穴１１に挿入されている。本実施形態では、ベア部２Ａの先端部２Ｃが、ファイバ穴１１の第二端１１Ｂから突出してレンズ部２０の後端面２１Ａに突き当てられている。接着剤３は、フェルール１の接着剤充填部１２に充填されて光ファイバ２（特にベア部２Ａ）をフェルール１に固定する。接着剤３は、特に光ファイバ２のうち接着剤充填部１２に位置する部位をフェルール１に固定する。 As shown in FIG. 5, the optical connector 100 of the present embodiment manufactured as described above includes a ferrule 1, an optical fiber 2, and an adhesive 3. The optical connector 100 of the present embodiment also includes the boots 4.
In the optical connector 100, the bare portion 2A of the optical fiber 2 is inserted into the fiber hole 11 from the first end 11A of the fiber hole 11 of the ferrule 1. In the present embodiment, the tip portion 2C of the bare portion 2A protrudes from the second end 11B of the fiber hole 11 and is abutted against the rear end surface 21A of the lens portion 20. The adhesive 3 is filled in the adhesive filling portion 12 of the ferrule 1 to fix the optical fiber 2 (particularly the bare portion 2A) to the ferrule 1. The adhesive 3 fixes a portion of the optical fiber 2 located at the adhesive filling portion 12 to the ferrule 1.
　以上説明したように、本実施形態のフェルール１は、ファイバ穴１１が形成されたフェルール本体１０を備え、ファイバ穴１１には光ファイバ２のベア部２Ａが挿入される。フェルール本体１０には、接着剤３を充填するための接着剤充填部１２と、中間空洞部１３と、が形成され、接着剤充填部１２および中間空洞部１３はファイバ穴１１に連通している。ファイバ穴１１の長手方向に直交する断面において、接着剤充填部１２の断面積はファイバ穴１１の断面積より大きい。長手方向において、中間空洞部１３はファイバ穴１１の中間に位置する。この構成によれば、接着剤充填部１２に充填された接着剤３が、ファイバ穴１１の第一端１１Ａからファイバ穴１１（特に第一分割穴１１１）と光ファイバ２との隙間に入り込んで毛管力などによってファイバ穴１１内を第二端１１Ｂに向けて進んでも、接着剤３は中間空洞部１３においてファイバ穴１１の外側に排出される。このため、接着剤３が第二分割穴１１２に入ること、及び、接着剤３がファイバ穴１１の第二端１１Ｂやその近くに到達することを抑制又は防止できる。これにより、ファイバ穴１１の第二端１１Ｂ側に位置する光ファイバ２の先端部２Ｃにおける光ファイバ２の軸方向が、接着剤３の硬化時における収縮によってファイバ穴１１の軸方向に対して傾斜することを抑制できる。
　したがって、接着剤３の収縮に基づく光ファイバ２の先端部２Ｃの傾斜を抑えて、光ファイバ２と他の光学部品との光信号の結合効率の低下を抑制できる。 As described above, the ferrule 1 of the present embodiment includes the ferrule main body 10 in which the fiber hole 11 is formed, and the bare portion 2A of the optical fiber 2 is inserted into the fiber hole 11. The ferrule body 10 is formed with an adhesive filling portion 12 for filling the adhesive 3 and an intermediate cavity portion 13, and the adhesive filling portion 12 and the intermediate cavity portion 13 communicate with the fiber hole 11. .. In the cross section orthogonal to the longitudinal direction of the fiber hole 11, the cross-sectional area of the adhesive filling portion 12 is larger than the cross-sectional area of the fiber hole 11. In the longitudinal direction, the intermediate cavity 13 is located in the middle of the fiber hole 11. According to this configuration, the adhesive 3 filled in the adhesive filling portion 12 enters the gap between the fiber hole 11 (particularly the first dividing hole 111) and the optical fiber 2 from the first end 11A of the fiber hole 11. Even if the adhesive 3 advances toward the second end 11B in the fiber hole 11 due to capillary force or the like, the adhesive 3 is discharged to the outside of the fiber hole 11 in the intermediate cavity 13. Therefore, it is possible to prevent or prevent the adhesive 3 from entering the second dividing hole 112 and the adhesive 3 from reaching the second end 11B of the fiber hole 11 or its vicinity. As a result, the axial direction of the optical fiber 2 at the tip 2C of the optical fiber 2 located on the second end 11B side of the fiber hole 11 is inclined with respect to the axial direction of the fiber hole 11 due to shrinkage of the adhesive 3 during curing. Can be suppressed.
Therefore, the inclination of the tip portion 2C of the optical fiber 2 due to the shrinkage of the adhesive 3 can be suppressed, and the decrease in the coupling efficiency of the optical signal between the optical fiber 2 and other optical components can be suppressed.
　特に、レンズ部２０を含む本実施形態のフェルール１では、レンズ部２０（特にレンズ本体２２）に対する光ファイバ２の先端部２Ｃの位置ずれを抑制又は防止できる。これにより、レンズ部２０に対する光ファイバ２の先端部２Ｃの位置ずれに基づく光信号の伝送損失を抑制できる。 In particular, in the ferrule 1 of the present embodiment including the lens portion 20, the misalignment of the tip portion 2C of the optical fiber 2 with respect to the lens portion 20 (particularly the lens body 22) can be suppressed or prevented. Thereby, the transmission loss of the optical signal due to the misalignment of the tip portion 2C of the optical fiber 2 with respect to the lens portion 20 can be suppressed.
　また、レンズ部２０を含む本実施形態のフェルール１によれば、ファイバ穴１１の第二端１１Ｂがフェルール本体１０の前端面１０Ｂに開口し、レンズ部２０の後端面２１Ａがフェルール本体１０の前端面１０Ｂに対して間隔をあけて配されている。このため、フェルール１を製造する際に、ベア部２Ａの先端部２Ｃが突き当たるレンズ部２０の後端面２１Ａの平面性を容易に確保することができる。この効果は、フェルール本体１０とレンズ部２０とが一体に形成される場合に特に有用である。 Further, according to the ferrule 1 of the present embodiment including the lens portion 20, the second end 11B of the fiber hole 11 opens to the front end surface 10B of the ferrule main body 10, and the rear end surface 21A of the lens portion 20 is the front end of the ferrule main body 10. They are arranged at intervals with respect to the surface 10B. Therefore, when manufacturing the ferrule 1, the flatness of the rear end surface 21A of the lens portion 20 to which the tip end portion 2C of the bare portion 2A abuts can be easily ensured. This effect is particularly useful when the ferrule body 10 and the lens portion 20 are integrally formed.
　また、本実施形態のフェルール１では、中間空洞部１３がフェルール１の外側に開口している。このため、中間空洞部１３に到達した接着剤３をフェルール１の外側に排出できる。これにより、ファイバ穴１１の第一端１１Ａからファイバ穴１１に入り込んだ接着剤３がファイバ穴１１の第二端１１Ｂやその近くに到達することをより確実に防止できる。 Further, in the ferrule 1 of the present embodiment, the intermediate cavity portion 13 is open to the outside of the ferrule 1. Therefore, the adhesive 3 that has reached the intermediate cavity 13 can be discharged to the outside of the ferrule 1. As a result, it is possible to more reliably prevent the adhesive 3 that has entered the fiber hole 11 from the first end 11A of the fiber hole 11 from reaching the second end 11B of the fiber hole 11 or its vicinity.
　また、本実施形態のフェルール１によれば、光ファイバ２との隙間に接着剤３が入りやすい第一分割穴１１１の長さＬ１１が、中間空洞部１３よりも前側に位置する第二分割穴１１２の長さＬ１２よりも短い。このため、ファイバ穴１１に入り込んだ接着剤３の収縮に伴って光ファイバ２に作用する力をより小さく抑えることができる。これにより、接着剤３の収縮に基づく光ファイバ２の先端部２Ｃの傾斜をさらに小さく抑えることができる。 Further, according to the ferrule 1 of the present embodiment, the length L11 of the first dividing hole 111 in which the adhesive 3 easily enters the gap with the optical fiber 2 is located in front of the intermediate cavity portion 13. The length of 112 is shorter than L12. Therefore, the force acting on the optical fiber 2 due to the shrinkage of the adhesive 3 that has entered the fiber hole 11 can be suppressed to a smaller size. As a result, the inclination of the tip portion 2C of the optical fiber 2 due to the shrinkage of the adhesive 3 can be further suppressed.
　また、本実施形態のフェルール１によれば、ファイバ穴１１の長さＬ１が接着剤充填部１２の長さＬ２よりも長い。このため、ファイバ穴１１の長さＬ１が接着剤充填部１２の長さＬ２以下である場合と比較して、接着剤充填部１２に充填される接着剤３の量をより小さく抑えることができる。これにより、硬化時における接着剤３の収縮量を小さく抑えることができる。その結果として、接着剤３の収縮に基づく光ファイバ２の先端部２Ｃの傾斜をさらに小さく抑えることができる。
　また、ファイバ穴１１の長さＬ１がより長くなることで、ファイバ穴１１において光ファイバ２の軸方向がファイバ穴１１の軸方向に対して傾斜する傾斜角度を小さく抑えることもできる。
　以上のことから、光信号の結合効率の低下をさらに抑制できる。 Further, according to the ferrule 1 of the present embodiment, the length L1 of the fiber hole 11 is longer than the length L2 of the adhesive filling portion 12. Therefore, the amount of the adhesive 3 filled in the adhesive filling portion 12 can be suppressed to be smaller than in the case where the length L1 of the fiber hole 11 is equal to or less than the length L2 of the adhesive filling portion 12. .. As a result, the amount of shrinkage of the adhesive 3 at the time of curing can be suppressed to a small size. As a result, the inclination of the tip portion 2C of the optical fiber 2 due to the shrinkage of the adhesive 3 can be further suppressed.
Further, by making the length L1 of the fiber hole 11 longer, it is possible to suppress the inclination angle at which the axial direction of the optical fiber 2 is inclined with respect to the axial direction of the fiber hole 11 in the fiber hole 11 to be small.
From the above, it is possible to further suppress a decrease in the coupling efficiency of the optical signal.
　また、本実施形態のフェルール１によれば、中間空洞部１３が外側に開口する。このため、ファイバ穴１１の長さＬ１が長くても、フェルール１を樹脂成形のみで製造することが可能となる。以下、この点についてより詳しく説明する。 Further, according to the ferrule 1 of the present embodiment, the intermediate cavity portion 13 opens to the outside. Therefore, even if the length L1 of the fiber hole 11 is long, the ferrule 1 can be manufactured only by resin molding. This point will be described in more detail below.
　ファイバ穴１１の長さＬ１が長い場合、フェルール１を樹脂成形するための金型には、ファイバ穴１１を形成するための細長いピンが必要となる。しかし、細長いピンは撓みやすいため、ファイバ穴１１を精度よく形成することが難しい。
　これに対して、金型に、細長いピンの長手方向の中間部を支持する支持部を設けることで、細長いピンが撓むことを防止できる。金型の支持部が細長いピンをその長手方向に対して直交する方向から支持した状態で、フェルール１の樹脂成形を実施することで、中間空洞部１３は、金型の支持部によって外側に開口するように形成される。 When the length L1 of the fiber hole 11 is long, the mold for resin-molding the ferrule 1 requires an elongated pin for forming the fiber hole 11. However, since the elongated pin is easily bent, it is difficult to accurately form the fiber hole 11.
On the other hand, by providing the mold with a support portion that supports the intermediate portion in the longitudinal direction of the elongated pin, it is possible to prevent the elongated pin from bending. By performing resin molding of ferrule 1 in a state where the support portion of the mold supports the elongated pin from the direction orthogonal to the longitudinal direction thereof, the intermediate cavity portion 13 is opened to the outside by the support portion of the mold. Is formed to do.
　また、本実施形態の光コネクタ１００は、上記フェルール１と、ファイバ穴１１に挿入されたベア部２Ａを含む光ファイバ２と、接着剤充填部１２に充填されて光ファイバ２をフェルール１に固定する接着剤３と、を備える。また、本実施形態の光コネクタの製造方法は、ベア部２Ａをファイバ穴１１に挿入する挿入工程と、接着剤充填部１２に接着剤３を充填する充填工程と、接着剤３を硬化させることで光ファイバ２をフェルール１に固定する固定工程と、を有する。これらの構成により、接着剤３の収縮に基づく光ファイバ２の先端部２Ｃの傾斜を抑えた光コネクタ１００を提供できる。 Further, the optical connector 100 of the present embodiment is filled with the ferrule 1, the optical fiber 2 including the bare portion 2A inserted in the fiber hole 11, and the adhesive filling portion 12 to fix the optical fiber 2 to the ferrule 1. The adhesive 3 and the adhesive 3 are provided. Further, the method for manufacturing the optical connector of the present embodiment includes an insertion step of inserting the bare portion 2A into the fiber hole 11, a filling step of filling the adhesive filling portion 12 with the adhesive 3, and curing the adhesive 3. It has a fixing step of fixing the optical fiber 2 to the ferrule 1. With these configurations, it is possible to provide the optical connector 100 in which the inclination of the tip portion 2C of the optical fiber 2 due to the shrinkage of the adhesive 3 is suppressed.
　以上、本発明の詳細について説明したが、本発明は上述した実施形態に限定されるものではなく、本発明の主旨を逸脱しない範囲において種々の変更を加えることができる。 Although the details of the present invention have been described above, the present invention is not limited to the above-described embodiment, and various modifications can be made without departing from the gist of the present invention.
　例えば、フェルール本体１０及びレンズ部２０は、別個に形成された上で、互いに固定されてもよい。 For example, the ferrule body 10 and the lens portion 20 may be formed separately and then fixed to each other.
　また、フェルール１は、例えばレンズ部２０を備えず、図６，７に例示するようにファイバ穴１１、接着剤充填部１２及び中間空洞部１３を含むフェルール本体１０のみによって構成されてもよい。 Further, the ferrule 1 may not include, for example, the lens portion 20, and may be composed only of the ferrule main body 10 including the fiber hole 11, the adhesive filling portion 12, and the intermediate cavity portion 13 as illustrated in FIGS. 6 and 7.
　また、フェルール１においては、例えば中間空洞部１３が外側に開口しなくてもよい。この場合、フェルール１（特にフェルール本体１０）は、例えば、樹脂成形された二つの分割体を互いに結合することで製造されてよい。すなわち、二つの分割体を結合することで、フェルールの内部にファイバ穴１１や中間空洞部１３が形成されてよい。 Further, in the ferrule 1, for example, the intermediate cavity portion 13 does not have to open to the outside. In this case, the ferrule 1 (particularly the ferrule body 10) may be manufactured, for example, by joining two resin-molded divided bodies to each other. That is, by joining the two divided bodies, the fiber hole 11 and the intermediate cavity portion 13 may be formed inside the ferrule.
　上記した光コネクタの製造方法は、少なくとも挿入工程、充填工程及び固定工程を備えればよく、例えばブーツ挿通工程を含まなくてもよい。 The above-mentioned method for manufacturing an optical connector may include at least an insertion step, a filling step, and a fixing step, and may not include, for example, a boot insertion step.
１…フェルール、２…光ファイバ、２Ａ…ベア部、３…接着剤、１０…フェルール本体、１０Ｂ…前端面、１１…ファイバ穴、１１Ａ…第一端、１１Ｂ…第二端、１１１…第一分割穴、１１２…第二分割穴、１２…接着剤充填部、１３…中間空洞部、２０…レンズ部、２１Ａ…後端面、１００…光コネクタ、Ｌ１…ファイバ穴１１の長さ、Ｌ１１…第一分割穴１１１の長さ、Ｌ１２…第二分割穴１１２の長さ、Ｌ２…接着剤充填部１２の長さ 1 ... Ferrule, 2 ... Optical fiber, 2A ... Bare part, 3 ... Adhesive, 10 ... Ferrule body, 10B ... Front end face, 11 ... Fiber hole, 11A ... First end, 11B ... Second end, 111 ... First Dividing hole, 112 ... Second dividing hole, 12 ... Adhesive filling part, 13 ... Intermediate cavity part, 20 ... Lens part, 21A ... Rear end face, 100 ... Optical connector, L1 ... Fiber hole 11 length, L11 ... First Length of one dividing hole 111, L12 ... Length of second dividing hole 112, L2 ... Length of adhesive filling portion 12

Claims (8)

  1. 　光ファイバのベア部が挿入されるファイバ穴を有するフェルールであって、
    　前記ファイバ穴が形成されたフェルール本体を備え、
    　前記フェルール本体には、接着剤を充填するための接着剤充填部と、中間空洞部と、が形成され、前記接着剤充填部および前記中間空洞部は前記ファイバ穴に連通し、
    　前記ファイバ穴の長手方向に直交する断面において、前記中間空洞部の断面積は前記ファイバ穴の断面積より大きく、
    　前記長手方向において、前記中間空洞部は前記ファイバ穴の中間に位置するフェルール。     A ferrule having a fiber hole into which a bare part of an optical fiber is inserted.
    The ferrule body having the fiber hole formed therein is provided.
    An adhesive filling portion for filling the adhesive and an intermediate cavity portion are formed in the ferrule body, and the adhesive filling portion and the intermediate cavity portion communicate with the fiber hole.
    In the cross section orthogonal to the longitudinal direction of the fiber hole, the cross-sectional area of the intermediate cavity portion is larger than the cross-sectional area of the fiber hole.
    In the longitudinal direction, the intermediate cavity is a ferrule located in the middle of the fiber hole.
  2. 　前記中間空洞部が前記フェルール本体の外側に開口する請求項１に記載のフェルール。 The ferrule according to claim 1, wherein the intermediate cavity portion opens to the outside of the ferrule body.
  3. 　前記ファイバ穴が、前記中間空洞部により、前記長手方向において前記接着剤充填部側から順番に並ぶ第一分割穴と第二分割穴とに分断され、
    　前記長手方向における前記第二分割穴の長さが、前記長手方向における前記第一分割穴の長さよりも長い請求項１又は請求項２に記載のフェルール。     The fiber hole is divided into a first dividing hole and a second dividing hole which are arranged in order from the adhesive filling portion side in the longitudinal direction by the intermediate cavity portion.
    The ferrule according to claim 1 or 2, wherein the length of the second dividing hole in the longitudinal direction is longer than the length of the first dividing hole in the longitudinal direction.
  4. 　前記長手方向における前記ファイバ穴の長さが、前記長手方向における前記接着剤充填部の長さよりも長い請求項１から請求項３のいずれか一項に記載のフェルール。 The ferrule according to any one of claims 1 to 3, wherein the length of the fiber hole in the longitudinal direction is longer than the length of the adhesive filling portion in the longitudinal direction.
  5. 　前記接着剤充填部とは反対側の前記ファイバ穴の端部に対向するレンズ部をさらに備える請求項１から請求項４のいずれか一項に記載のフェルール。 The ferrule according to any one of claims 1 to 4, further comprising a lens portion facing the end of the fiber hole on the opposite side of the adhesive filling portion.
  6. 　前記ファイバ穴が前記フェルール本体の前端面に開口し、
    　前記レンズ部の後端面が、前記長手方向において前記フェルール本体の前記前端面に対向し、かつ前記前端面に対して間隔をあけて配される請求項５に記載のフェルール。     The fiber hole opens in the front end surface of the ferrule body,
    The ferrule according to claim 5, wherein the rear end surface of the lens portion faces the front end surface of the ferrule body in the longitudinal direction and is arranged at a distance from the front end surface.
  7. 　請求項１から請求項６のいずれか一項に記載のフェルールと、
    　前記ファイバ穴に挿入されたベア部を含む光ファイバと、
    　前記接着剤充填部に充填されて前記光ファイバを前記フェルールに固定する接着剤と、を備える光コネクタ。     The ferrule according to any one of claims 1 to 6, and the ferrule.
    An optical fiber including a bare portion inserted into the fiber hole and
    An optical connector comprising an adhesive that fills the adhesive filling portion and fixes the optical fiber to the ferrule.
  8. 　ベア部を含む光ファイバを請求項１から請求項６のいずれか一項のフェルールに取り付けて光コネクタを製造する光コネクタの製造方法であって、
    　前記ベア部を前記ファイバ穴に挿入し、
    　前記接着剤充填部に接着剤を充填し、
    　前記接着剤を硬化させることで前記光ファイバを前記フェルールに固定する、光コネクタの製造方法。     A method for manufacturing an optical connector, wherein an optical fiber including a bare portion is attached to a ferrule according to any one of claims 1 to 6 to manufacture an optical connector.
    The bare portion is inserted into the fiber hole, and the bare portion is inserted into the fiber hole.
    The adhesive filling portion is filled with an adhesive, and the adhesive is filled.
    A method for manufacturing an optical connector, in which the optical fiber is fixed to the ferrule by curing the adhesive.
PCT/JP2020/031071 2019-10-01 2020-08-18 Ferrule, optical connector, and method for manufacturing optical connector WO2021065224A1 (en)

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JP2016071194A (en) * 2014-09-30 2016-05-09 住友電気工業株式会社 Ferrule
JP2018101023A (en) * 2016-12-19 2018-06-28 株式会社フジクラ Ferrule, optical fiber-attached ferrule, and method of manufacturing optical fiber-attached ferrule
JP2019032459A (en) * 2017-08-09 2019-02-28 富士通コンポーネント株式会社 Ferrule and method of manufacturing ferrule

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