WO2024042781A1 - Optical connector - Google Patents

Optical connector Download PDF

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Publication number
WO2024042781A1
WO2024042781A1 PCT/JP2023/016879 JP2023016879W WO2024042781A1 WO 2024042781 A1 WO2024042781 A1 WO 2024042781A1 JP 2023016879 W JP2023016879 W JP 2023016879W WO 2024042781 A1 WO2024042781 A1 WO 2024042781A1
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WO
WIPO (PCT)
Prior art keywords
ferrule
adhesive
optical connector
optical
insertion hole
Prior art date
Application number
PCT/JP2023/016879
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French (fr)
Japanese (ja)
Inventor
真也 本田
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 WO2024042781A1 publication Critical patent/WO2024042781A1/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
    • G02B6/36—Mechanical coupling means

Definitions

  • the present invention relates to an optical connector.
  • This application claims priority to Japanese Patent Application No. 2022-132951 filed in Japan on August 24, 2022, the contents of which are incorporated herein.
  • Patent Document 1 discloses a structure in which a plurality of optical fibers are inserted into one of the insertion holes of a ferrule. According to an optical connector having such a structure, for example, a plurality of optical fibers can be connected to one multi-core fiber.
  • the diameter of the tip end of each optical fiber may be reduced by etching or the like. This is to bring the thinned tips into close contact with each other in the insertion hole, and to align the position of the core of each optical fiber with the position of each core of the multi-core fiber to be connected.
  • an adhesive such as resin.
  • the adhesive may absorb moisture and expand inside the ferrule.
  • the expanded adhesive can put pressure on the optical fiber (particularly at the attenuated portion) and cause bending losses.
  • the present invention has been made in consideration of such circumstances, and an object of the present invention is to provide an optical connector that can suppress bending loss of optical fibers due to moisture absorption of adhesive.
  • an optical connector includes a plurality of optical fibers each having a bare fiber having a large diameter part and a small diameter part having an outer diameter smaller than the large diameter part.
  • a ferrule having an insertion hole into which a plurality of bare fibers can be inserted, and an injection hole communicating with the insertion hole;
  • the ferrule includes an adhesive that fixes the fiber to the ferrule, and a low hygroscopic layer that is made of a low hygroscopic material that has lower hygroscopicity than the adhesive and seals the injection hole.
  • the adhesive may be a thermosetting resin
  • the low hygroscopic material may be a UV curable resin
  • a water-repellent layer may be provided on the surface of the low moisture absorption layer.
  • the ferrule further includes an introduction hole different from the injection hole for introducing the plurality of optical fibers into the insertion hole.
  • the space inside the introduction hole may be sealed with the low hygroscopic material.
  • the low hygroscopic material may be the same as the material of the ferrule.
  • the plurality of optical fibers may be introduced into the insertion hole through the injection hole.
  • an optical connector that can suppress bending loss of optical fibers due to moisture absorption of adhesive.
  • FIG. 1 is a perspective view of an optical connector according to a first embodiment.
  • FIG. 2 is a cross-sectional view taken along line II-II in FIG. 1; 2 is a perspective view of a plurality of optical fibers extracted from the optical connector shown in FIG. 1.
  • FIG. FIG. 3 is a cross-sectional view taken along the line IV-IV in FIG. 2;
  • FIG. 2 is a view taken in the direction of arrow V in FIG. 1;
  • FIG. 3 is a perspective view of an optical connector according to a second embodiment.
  • 7 is a cross-sectional view taken along the line VII-VII in FIG. 6; FIG.
  • the optical connector 1A includes a ferrule 10, a plurality of optical fibers 20, two positioning pins 40, and a boot 60. Note that the optical connector 1A does not need to include the positioning pin 40 and the boot 60.
  • the ferrule 10 has a connecting end surface 10a, a rear end surface 10b, an insertion hole 11, an injection hole 12, two positioning holes 13, and an introduction hole 14 (see FIG. 2).
  • the connection end surface 10a is a surface that is abutted against another connector or the like when the optical connector 1A is connected to another connector or the like.
  • the insertion hole 11 and the two positioning holes 13 are open to the connection end surface 10a.
  • the introduction hole 14 opens on the rear end surface 10b and communicates with the insertion hole 11.
  • the optical fiber 20 is introduced into the single insertion hole 11 through the introduction hole 14 .
  • a positioning pin 40 is inserted into each of the two positioning holes 13.
  • a direction parallel to the central axis O of the insertion hole 11 is referred to as a Z direction, an axial direction Z, or a longitudinal direction Z.
  • the direction from the rear end surface 10b of the ferrule 10 toward the connection end surface 10a along the longitudinal direction Z is referred to as the +Z direction, the front, or the tip side.
  • the direction opposite to the +Z direction is referred to as the -Z direction, rearward, or proximal side.
  • a cross section perpendicular to the longitudinal direction Z is called a cross section.
  • one direction perpendicular to the longitudinal direction Z is referred to as a first direction X.
  • the first direction X is also the direction in which the two positioning holes 13 are arranged.
  • a direction perpendicular to both the longitudinal direction Z and the first direction X is referred to as a second direction Y.
  • the above-mentioned cross section is a cross section extending along the first direction X and the second direction Y.
  • the insertion hole 11 is arranged so as to be sandwiched between two positioning holes 13.
  • the injection hole 12 is open in one end surface of the ferrule 10 facing in the second direction Y.
  • the injection hole 12 communicates with the internal space of the ferrule 10 and the insertion hole 11 .
  • FIG. 3 is an extracted diagram of the plurality of optical fibers 20 shown in FIG. 1.
  • the optical connector 1A of this embodiment has four optical fibers 20.
  • the number of optical fibers 20 may be changed.
  • Each optical fiber 20 has a bare fiber 21 and a coating 22.
  • the bare fiber 21 is made of quartz glass, for example.
  • the covering 22 partially covers the bare fiber 21 and has the role of protecting the bare fiber 21.
  • the covering 22 is made of resin or the like.
  • the material of the coating 22 may be a UV curable resin.
  • the coating 22 is not provided, and the bare fiber 21 is exposed. The exposed bare fiber 21 is inserted into the insertion hole 11 of the ferrule 10.
  • the bare fiber 21 has a small diameter portion 21a, a large diameter portion 21b, and a tapered portion 21c.
  • the outer diameter of the small diameter portion 21a is smaller than the outer diameter of the large diameter portion 21b.
  • the small diameter portion 21a is located at the tip of the bare fiber 21.
  • the tapered portion 21c is located between the small diameter portion 21a and the large diameter portion 21b.
  • the tapered portion 21c has an outer diameter that gradually decreases toward the front.
  • the small diameter portion 21a and the tapered portion 21c can be formed by making the end portion of the bare fiber 21, which has a constant outer diameter (the same outer diameter as the large diameter portion 21b) in the longitudinal direction Z, thinner by, for example, etching.
  • the four small diameter portions 21a of the four optical fibers 20 are inserted into one insertion hole 11 of the ferrule 10.
  • the bare fiber 21 does not need to have the tapered portion 21c. That is, the bare fiber 21 may have a shape in which the small diameter portion 21a and the large diameter portion 21b are connected.
  • FIG. 4 is a cross-sectional view of the optical fiber 20.
  • the bare fiber 21 has a core 21d and a cladding 21e.
  • the cladding 21e is arranged to surround the core 21d.
  • the refractive index of the cladding 21e is lower than that of the core 21d. Therefore, the optical fiber 20 can confine light inside the core 21d.
  • the boot 60 is a cylindrical member into which a plurality of optical fibers 20 are inserted.
  • the front end of the boot 60 is inserted into the introduction hole 14 of the ferrule 10. Thereby, the boot 60 is fixed to the rear end of the ferrule 10.
  • the boot 60 has the role of protecting the optical fiber 20.
  • the adhesive 30 has the function of fixing the plurality of optical fibers 20 to the ferrule 10.
  • thermosetting resin can be used. More specifically, the material of the adhesive 30 may be epoxy resin.
  • the adhesive 30 may absorb moisture and expand inside the ferrule 10.
  • the expanded adhesive 30 may apply pressure particularly to the small diameter portion 21a, causing bending loss.
  • at least a portion (rear end portion) of each small diameter portion 21a is held by the adhesive 30 while being bent, as shown in FIG. This is because even if it is attempted to make the four small diameter portions 21a come into close contact with each other over the entire longitudinal direction Z, the large diameter portions 21b will structurally interfere with each other. Then, stress concentration due to the expansion of the adhesive 30 is likely to occur in the bent portion as described above, and bending loss is likely to occur.
  • the injection hole 12 is sealed with a low moisture absorption layer 50 for suppressing moisture absorption of the adhesive 30.
  • the low moisture absorption layer 50 is formed of a low moisture absorption material that has lower moisture absorption (water absorption rate) than the adhesive 30. Thereby, bending loss of the optical fiber 20 due to moisture absorption of the adhesive 30 can be suppressed.
  • the hygroscopicity (water absorption rate) of the adhesive 30 is, for example, about 2%. In this case, the hygroscopicity (water absorption rate) of the low hygroscopic material is less than 2% (for example, 1% or less).
  • the low moisture absorption material may have lower moisture permeability than the adhesive 30.
  • the moisture permeability of the adhesive 30 is, for example, a moisture absorption coefficient of 1.0 ⁇ 10 ⁇ 7 [cc ⁇ cm/cmHg ⁇ cm 2 ⁇ s] (measurement conditions: 85° C., 85% RH).
  • the type of low hygroscopic material for the low hygroscopic layer 50 is not particularly limited, but for example, acrylic resin, epoxy resin, urethane resin, silicone resin, etc. can be employed.
  • acrylic resin for example, UV-curable acrylic resin ThreeBond 3030 (water absorption rate 0.8%) manufactured by ThreeBond Co., Ltd., UV-cured acrylic resin World Lock No. 0.27%) and ultraviolet curing acrylic resin Aronix EXT003-182 (water absorption rate 0.04%) manufactured by Toa Kogyo Co., Ltd. Since these resins have a water absorption rate of 1% or less, they can be suitably used as the low moisture absorption layer 50.
  • epoxy resins examples include AUV-8800 (water absorption rate 0.4%), which is an ultraviolet curable epoxy resin manufactured by Nitta Gelatin Co., Ltd., and examples of urethane resins include ultraviolet curable epoxy resin manufactured by DYMAX Co., Ltd. 111-MSK (water absorption rate 0.6%), which is a type urethane resin, is mentioned, and examples of silicone resin include KR-470 (water absorption rate 0.5%), which is an ultraviolet curing silicone resin manufactured by Shin-Etsu Chemical Co., Ltd. ). Since these resins also have a water absorption rate of 1% or less like the above-mentioned acrylic resins, they can be suitably used as the low moisture absorption layer 50.
  • the low hygroscopic material forming the low hygroscopic layer 50 is preferably a UV curable resin. If both the low hygroscopic material and the adhesive 30 are thermosetting resins, the heat applied to cure the low hygroscopic material may have an adverse effect on the already cured adhesive 30. By using a UV curable resin as the low hygroscopic material, the above possibility can be avoided because ultraviolet rays instead of heat are used to cure the low hygroscopic material.
  • a water-repellent layer 51 is provided on the surface of the low moisture absorption layer 50 according to this embodiment. More specifically, the water-repellent layer 51 is provided on the surface of the low moisture absorption layer 50 that faces the outside of the ferrule 10 .
  • the water-repellent layer 51 is a layer formed by treating the surface of the low moisture absorption layer 50 to be water-repellent.
  • a material for forming the water-repellent layer 51 for example, a silicon-based water repellent, a fluorine-based water repellent, or the like can be used.
  • the water repellent layer 51 may not be provided on the surface of the low moisture absorption layer 50.
  • the water-repellent layer 51 may have a contact angle of water droplets on its surface of 100 degrees or more.
  • Examples of the water-repellent layer 51 include Novec 1700 (contact angle: 105 degrees), a fluorine-based coating agent manufactured by 3M, acrylic resin ThreeBond 2907D (contact angle: 103 degrees), a silane-based coating agent manufactured by ThreeBond, etc. can be adopted.
  • the moisture resistance of the low moisture absorption layer 50 can be improved more effectively.
  • the space inside the introduction hole 14 of the ferrule 10 is also sealed with a low hygroscopic material.
  • the space inside the introduction hole 14 means the gaps G1 to G3 shown in the figure.
  • the gap G1 is a gap between the outer peripheral surface of the boot 60 and the inner peripheral surface of the introduction hole 14.
  • Gap G2 is a gap between the outer peripheral surface of optical fiber 20 and the inner peripheral surface of boot 60.
  • the gap G3 is a gap (space) surrounded by the outer peripheral surfaces of the four optical fibers 20.
  • the space inside the introduction hole 14 does not need to be sealed with a low hygroscopic material.
  • the optical connector 1A includes a plurality of optical fibers each having a bare fiber 21 having a large diameter portion 21b and a small diameter portion 21a having a smaller outer diameter than the large diameter portion 21b. 20, a single insertion hole 11 through which a plurality of bare fibers 21 can be inserted, and an injection hole 12 communicating with the insertion hole 11, and a state in which a plurality of bare fibers 21 are inserted into the insertion hole 11.
  • an adhesive 30 for fixing the plurality of optical fibers 20 to the ferrule 10 and a low hygroscopic layer 50 that is formed of a low hygroscopic material having a hygroscopicity lower than that of the adhesive 30 and seals the injection hole 12.
  • a low hygroscopic layer 50 that is formed of a low hygroscopic material having a hygroscopicity lower than that of the adhesive 30 and seals the injection hole 12.
  • the adhesive 30 may be a thermosetting resin, and the low hygroscopic material may be a UV curable resin. According to this configuration, the formation of the low moisture absorption layer 50 is less likely to have an adverse effect on the adhesive 30.
  • a water repellent layer 51 may be provided on the surface of the low moisture absorption layer 50. According to this configuration, the possibility that the adhesive 30 absorbs moisture can be further reduced, and the bending loss of the optical fiber 20 can be suppressed more effectively.
  • the ferrule 10 further includes an introduction hole 14 different from the injection hole 12 for introducing the plurality of optical fibers 20 into the insertion hole 11, and the space inside the introduction hole 14 is sealed with a low hygroscopic material. You can leave it there. According to this configuration, the possibility that the adhesive 30 absorbs moisture can be further reduced, and the bending loss of the optical fiber 20 can be suppressed more reliably.
  • the number of insertion holes 11 is one, but a plurality of insertion holes may be provided. Even in that case, the configuration is such that a plurality of optical fibers are inserted through a single insertion hole.
  • the structure of the ferrule 70 is different from the structure of the ferrule 10 according to the first embodiment.
  • the ferrule 70 according to the present embodiment includes a ferrule main body portion 71 and a flange portion 72 that are formed separately.
  • the front surface of the ferrule main body portion 71 is the connection end surface 70a of the ferrule 70
  • the rear surface of the flange portion 72 is the rear end surface 70b of the ferrule 70.
  • An insertion hole 73 is opened in the connection end surface 70a as in the first embodiment.
  • a holding hole 72a is opened in the front surface of the flange portion 72.
  • the flange portion 72 holds the ferrule main body 71 by inserting the rear end portion of the ferrule main body 71 into the holding hole 72a.
  • the injection hole 74 is open to the rear end surface 70b of the ferrule 70.
  • the optical connector 1B includes a low moisture absorption layer 50 that seals the injection hole 74, similarly to the optical connector 1A according to the first embodiment.
  • the low moisture absorption layer 50 according to this embodiment is located at the rear end of the ferrule 70.
  • the optical fiber 20 is introduced into the insertion hole 73 through the injection hole 74. That is, the injection hole 74 according to this embodiment also functions as the introduction hole 14 in the first embodiment.
  • the plurality of optical fibers 20 are introduced into the insertion hole 73 through the injection hole 74. Also in this case, by providing the low moisture absorption layer 50 that seals the injection hole 74, bending loss of the optical fiber 20 due to moisture absorption of the adhesive 30 can be suppressed, as in the first embodiment.
  • the low moisture absorption layer 50 may be a lid portion formed of the same material as the ferrule 10.
  • the low moisture absorption material forming the low moisture absorption layer 50 may be the same as the material of the ferrule 10.
  • Such a low moisture absorption layer 50 can be formed, for example, by injecting the adhesive 30 into the ferrule 10 and then welding the injection hole 12.
  • a lid made of the same material as the ferrule 10 may be prepared separately from the ferrule 10, and the injection hole 12 may be sealed with the lid.
  • the material of the ferrule 10 is, for example, PPS (polyphenylene sulfide).
  • ferrules 10 and 70 may have a plurality of insertion holes 11 and 73 through which the plurality of optical fibers 20 can be inserted.

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  • Physics & Mathematics (AREA)
  • General Physics & Mathematics (AREA)
  • Optics & Photonics (AREA)
  • Mechanical Coupling Of Light Guides (AREA)

Abstract

This optical connector comprises: a plurality of optical fibers that respectively have bare fibers each having a large-diameter portion and a small-diameter portion having a smaller outer diameter than that of the large-diameter portion; a ferrule that has an insertion hole into which the plurality of bare fibers can be inserted, and an injection hole communicating with the insertion hole; an adhesive that secures the plurality of optical fibers to the ferrule in a state where the plurality of bare fibers are inserted into the insertion hole; and a low hygroscopic layer that is formed by a low hygroscopic material having lower hygroscopicity than that of the adhesive and seals the injection hole.

Description

光コネクタoptical connector
　本発明は、光コネクタに関する。
　本願は、２０２２年８月２４日に日本に出願された特願２０２２－１３２９５１号について優先権を主張し、その内容をここに援用する。 The present invention relates to an optical connector.
This application claims priority to Japanese Patent Application No. 2022-132951 filed in Japan on August 24, 2022, the contents of which are incorporated herein.
　特許文献１には、フェルールが有する挿通孔の１つに、複数の光ファイバを挿入した構造が開示されている。このような構造を有する光コネクタによれば、例えば、複数の光ファイバを、１本のマルチコアファイバに接続することができる。 Patent Document 1 discloses a structure in which a plurality of optical fibers are inserted into one of the insertion holes of a ferrule. According to an optical connector having such a structure, for example, a plurality of optical fibers can be connected to one multi-core fiber.
　１本のマルチコアファイバと複数の光ファイバとを接続する上記接続構造においては、各光ファイバの先端部をエッチング等によって細径化場合がある。これは、細径化された先端部同士を上記挿通孔内で密接させ、各光ファイバが有するコアの位置を、接続対象のマルチコアファイバが有する各コアの位置に合わせるためである。 In the above connection structure that connects one multi-core fiber and a plurality of optical fibers, the diameter of the tip end of each optical fiber may be reduced by etching or the like. This is to bring the thinned tips into close contact with each other in the insertion hole, and to align the position of the core of each optical fiber with the position of each core of the multi-core fiber to be connected.
国際公開第２０１４／１３２９８９号International Publication No. 2014/132989
　ところで、光ファイバをフェルールに対して固定するには、樹脂等の接着剤を用いるのが一般的である。しかし、例えば高湿度環境下においては、接着剤が吸湿し、フェルールの内部において膨張する場合がある。膨張した接着剤は、光ファイバ（特に細径化された部分）に圧力を加え、曲げ損失を生じさせる可能性がある。 Incidentally, to fix the optical fiber to the ferrule, it is common to use an adhesive such as resin. However, for example, in a high humidity environment, the adhesive may absorb moisture and expand inside the ferrule. The expanded adhesive can put pressure on the optical fiber (particularly at the attenuated portion) and cause bending losses.
　本発明は、このような事情を考慮してなされ、接着剤の吸湿に起因する光ファイバの曲げ損失を抑制することが可能な光コネクタを提供することを目的とする。 The present invention has been made in consideration of such circumstances, and an object of the present invention is to provide an optical connector that can suppress bending loss of optical fibers due to moisture absorption of adhesive.
　上記課題を解決するために、本発明の態様１に係る光コネクタは、大径部と、前記大径部よりも小さい外径を有する小径部と、を有するベアファイバを各々有する複数の光ファイバと、複数の前記ベアファイバを挿通可能な挿通孔と、前記挿通孔と連通する注入孔と、を有するフェルールと、前記複数のベアファイバが前記挿通孔に挿通された状態で、前記複数の光ファイバを前記フェルールに固定する接着剤と、前記接着剤よりも低い吸湿性を有する低吸湿性素材で形成され、前記注入孔を封止する低吸湿層と、を備える。 In order to solve the above problems, an optical connector according to aspect 1 of the present invention includes a plurality of optical fibers each having a bare fiber having a large diameter part and a small diameter part having an outer diameter smaller than the large diameter part. a ferrule having an insertion hole into which a plurality of bare fibers can be inserted, and an injection hole communicating with the insertion hole; The ferrule includes an adhesive that fixes the fiber to the ferrule, and a low hygroscopic layer that is made of a low hygroscopic material that has lower hygroscopicity than the adhesive and seals the injection hole.
　また、本発明の態様２は、態様１の光コネクタにおいて、前記接着剤は、熱硬化性樹脂であり、前記低吸湿性素材は、ＵＶ硬化型樹脂であってもよい。 Furthermore, in a second aspect of the present invention, in the optical connector of aspect 1, the adhesive may be a thermosetting resin, and the low hygroscopic material may be a UV curable resin.
　また、本発明の態様３は、態様１または態様２の光コネクタにおいて、前記低吸湿層の表面に撥水層が設けられていてもよい。 Furthermore, in the third aspect of the present invention, in the optical connector of the first aspect or the second aspect, a water-repellent layer may be provided on the surface of the low moisture absorption layer.
　また、本発明の態様４は、態様１から態様３のいずれか一つの光コネクタにおいて、前記フェルールは、前記複数の光ファイバを前記挿通孔に導入する、前記注入孔とは異なる導入孔をさらに有し、前記導入孔の内側の空間は、前記低吸湿性素材によって封止されていてもよい。 Further, according to an aspect 4 of the present invention, in the optical connector according to any one of aspects 1 to 3, the ferrule further includes an introduction hole different from the injection hole for introducing the plurality of optical fibers into the insertion hole. The space inside the introduction hole may be sealed with the low hygroscopic material.
　また、本発明の態様５は、態様４の光コネクタにおいて、前記低吸湿性素材は、前記フェルールの素材と同一であってもよい。 Furthermore, in a fifth aspect of the present invention, in the optical connector of aspect 4, the low hygroscopic material may be the same as the material of the ferrule.
　また、本発明の態様６は、態様１から態様３のいずれか一つの光コネクタにおいて、前記複数の光ファイバは、前記注入孔を通して前記挿通孔に導入されていてもよい。 Furthermore, according to a sixth aspect of the present invention, in the optical connector according to any one of aspects 1 to 3, the plurality of optical fibers may be introduced into the insertion hole through the injection hole.
　本発明の上記態様によれば、接着剤の吸湿に起因する光ファイバの曲げ損失を抑制することが可能な光コネクタを提供できる。 According to the above aspect of the present invention, it is possible to provide an optical connector that can suppress bending loss of optical fibers due to moisture absorption of adhesive.
第１実施形態に係る光コネクタの斜視図である。FIG. 1 is a perspective view of an optical connector according to a first embodiment. 図１のＩＩ－ＩＩ断面矢視図である。FIG. 2 is a cross-sectional view taken along line II-II in FIG. 1; 図１に示す光コネクタのうち、複数の光ファイバを抜き出した斜視図である。2 is a perspective view of a plurality of optical fibers extracted from the optical connector shown in FIG. 1. FIG. 図２のＩＶ－ＩＶ断面矢視図である。FIG. 3 is a cross-sectional view taken along the line IV-IV in FIG. 2; 図１のＶ方向矢視図である。FIG. 2 is a view taken in the direction of arrow V in FIG. 1; 第２実施形態に係る光コネクタの斜視図である。FIG. 3 is a perspective view of an optical connector according to a second embodiment. 図６のＶＩＩ－ＶＩＩ断面矢視図である。7 is a cross-sectional view taken along the line VII-VII in FIG. 6; FIG.
（第１実施形態）
　以下、第１実施形態に係る光コネクタについて図面に基づいて説明する。
　図１に示すように、光コネクタ１Ａは、フェルール１０と、複数の光ファイバ２０と、２つの位置決めピン４０と、ブーツ６０と、を備える。なお、光コネクタ１Ａは位置決めピン４０およびブーツ６０を備えていなくてもよい。 (First embodiment)
Hereinafter, the optical connector according to the first embodiment will be described based on the drawings.
As shown in FIG. 1, the optical connector 1A includes a ferrule 10, a plurality of optical fibers 20, two positioning pins 40, and a boot 60. Note that the optical connector 1A does not need to include the positioning pin 40 and the boot 60.
　フェルール１０は、接続端面１０ａと、後端面１０ｂと、挿通孔１１と、注入孔１２と、２つの位置決め孔１３と、導入孔１４（図２参照）と、を有している。接続端面１０ａは、光コネクタ１Ａが他のコネクタ等と接続される際に、他のコネクタ等に突き当てられる面である。挿通孔１１および２つの位置決め孔１３は、接続端面１０ａに開口している。図２に示すように、導入孔１４は、後端面１０ｂに開口し、挿通孔１１と連通している。光ファイバ２０は、導入孔１４を通して単一の挿通孔１１に導入されている。図１に示すように、２つの位置決め孔１３にはそれぞれ、位置決めピン４０が挿通されている。 The ferrule 10 has a connecting end surface 10a, a rear end surface 10b, an insertion hole 11, an injection hole 12, two positioning holes 13, and an introduction hole 14 (see FIG. 2). The connection end surface 10a is a surface that is abutted against another connector or the like when the optical connector 1A is connected to another connector or the like. The insertion hole 11 and the two positioning holes 13 are open to the connection end surface 10a. As shown in FIG. 2, the introduction hole 14 opens on the rear end surface 10b and communicates with the insertion hole 11. The optical fiber 20 is introduced into the single insertion hole 11 through the introduction hole 14 . As shown in FIG. 1, a positioning pin 40 is inserted into each of the two positioning holes 13.
（方向定義）
　本明細書では、挿通孔１１の中心軸線Ｏと平行な方向を、Ｚ方向、軸方向Ｚ、または長手方向Ｚと称する。長手方向Ｚに沿って、フェルール１０の後端面１０ｂから接続端面１０ａに向かう向きを、＋Ｚの向き、前方、または先端側と称する。＋Ｚの向きとは反対の向きを、－Ｚの向き、後方、または基端側と称する。長手方向Ｚに直交する断面を横断面という。また、本実施形態では、長手方向Ｚに直交する一方向を、第１方向Ｘと称する。第１方向Ｘは、２つの位置決め孔１３が並べられた方向でもある。長手方向Ｚおよび第１方向Ｘの双方に直交する方向を、第２方向Ｙと称する。上述した横断面は、第１方向Ｘおよび第２方向Ｙに沿って延在する断面である。 (direction definition)
In this specification, a direction parallel to the central axis O of the insertion hole 11 is referred to as a Z direction, an axial direction Z, or a longitudinal direction Z. The direction from the rear end surface 10b of the ferrule 10 toward the connection end surface 10a along the longitudinal direction Z is referred to as the +Z direction, the front, or the tip side. The direction opposite to the +Z direction is referred to as the -Z direction, rearward, or proximal side. A cross section perpendicular to the longitudinal direction Z is called a cross section. Furthermore, in this embodiment, one direction perpendicular to the longitudinal direction Z is referred to as a first direction X. The first direction X is also the direction in which the two positioning holes 13 are arranged. A direction perpendicular to both the longitudinal direction Z and the first direction X is referred to as a second direction Y. The above-mentioned cross section is a cross section extending along the first direction X and the second direction Y.
　接続端面１０ａにおいて、挿通孔１１は、２つの位置決め孔１３に挟まれるように配置されている。注入孔１２は、フェルール１０が有する、第２方向Ｙに向く１つの端面に開口している。注入孔１２は、フェルール１０の内部空間および挿通孔１１に連通している。光コネクタ１Ａが組み立てられる際、注入孔１２を通して、接着剤３０が光コネクタ１Ａの内部に注入される。注入された接着剤３０は、挿通孔１１の内部にも進入する。 In the connection end surface 10a, the insertion hole 11 is arranged so as to be sandwiched between two positioning holes 13. The injection hole 12 is open in one end surface of the ferrule 10 facing in the second direction Y. The injection hole 12 communicates with the internal space of the ferrule 10 and the insertion hole 11 . When the optical connector 1A is assembled, the adhesive 30 is injected into the optical connector 1A through the injection hole 12. The injected adhesive 30 also enters the inside of the insertion hole 11 .
　図３は、図１に示す複数の光ファイバ２０を抜き出した図である。図３に示すように、本実施形態の光コネクタ１Ａは、４本の光ファイバ２０を有している。ただし、光ファイバ２０の数は変更してもよい。各光ファイバ２０は、ベアファイバ２１と、被覆２２と、を有している。ベアファイバ２１は、例えば石英ガラスによって形成されている。被覆２２は、ベアファイバ２１を部分的に覆っており、ベアファイバ２１を保護する役割を有する。被覆２２は、樹脂等によって形成されている。例えば、被覆２２の材質はＵＶ硬化型樹脂であってもよい。各光ファイバ２０の前方の端部では、被覆２２が設けられておらず、ベアファイバ２１が露出している。露出したベアファイバ２１が、フェルール１０の挿通孔１１に挿通されている。 FIG. 3 is an extracted diagram of the plurality of optical fibers 20 shown in FIG. 1. As shown in FIG. 3, the optical connector 1A of this embodiment has four optical fibers 20. However, the number of optical fibers 20 may be changed. Each optical fiber 20 has a bare fiber 21 and a coating 22. The bare fiber 21 is made of quartz glass, for example. The covering 22 partially covers the bare fiber 21 and has the role of protecting the bare fiber 21. The covering 22 is made of resin or the like. For example, the material of the coating 22 may be a UV curable resin. At the front end of each optical fiber 20, the coating 22 is not provided, and the bare fiber 21 is exposed. The exposed bare fiber 21 is inserted into the insertion hole 11 of the ferrule 10.
　ベアファイバ２１は、小径部２１ａと、大径部２１ｂと、テーパ部２１ｃと、を有している。小径部２１ａの外径は、大径部２１ｂの外径よりも小さい。小径部２１ａは、ベアファイバ２１の先端部に位置する。テーパ部２１ｃは、小径部２１ａと大径部２１ｂとの間に位置する。テーパ部２１ｃは、前方に向かうにしたがって漸次小さくなる外径を有する。小径部２１ａおよびテーパ部２１ｃは、長手方向Ｚにおいて一定の外径（大径部２１ｂと同じ外径）を有するベアファイバ２１の端部を、例えばエッチング等によって細くすることで形成できる。本実施形態では、４本の光ファイバ２０が有する４本の小径部２１ａが、フェルール１０が有する１つの挿通孔１１に挿通されている。なお、ベアファイバ２１はテーパ部２１ｃを有していなくてもよい。すなわち、ベアファイバ２１は、小径部２１ａと大径部２１ｂとが接続された形状を有していてもよい。 The bare fiber 21 has a small diameter portion 21a, a large diameter portion 21b, and a tapered portion 21c. The outer diameter of the small diameter portion 21a is smaller than the outer diameter of the large diameter portion 21b. The small diameter portion 21a is located at the tip of the bare fiber 21. The tapered portion 21c is located between the small diameter portion 21a and the large diameter portion 21b. The tapered portion 21c has an outer diameter that gradually decreases toward the front. The small diameter portion 21a and the tapered portion 21c can be formed by making the end portion of the bare fiber 21, which has a constant outer diameter (the same outer diameter as the large diameter portion 21b) in the longitudinal direction Z, thinner by, for example, etching. In this embodiment, the four small diameter portions 21a of the four optical fibers 20 are inserted into one insertion hole 11 of the ferrule 10. Note that the bare fiber 21 does not need to have the tapered portion 21c. That is, the bare fiber 21 may have a shape in which the small diameter portion 21a and the large diameter portion 21b are connected.
　図４は、光ファイバ２０の横断面図である。図４に示すように、ベアファイバ２１は、コア２１ｄおよびクラッド２１ｅを有している。クラッド２１ｅはコア２１ｄを囲むように配置される。クラッド２１ｅの屈折率はコア２１ｄの屈折率よりも低い。このため、光ファイバ２０はコア２１ｄの内部に光を閉じ込めることができる。 FIG. 4 is a cross-sectional view of the optical fiber 20. As shown in FIG. 4, the bare fiber 21 has a core 21d and a cladding 21e. The cladding 21e is arranged to surround the core 21d. The refractive index of the cladding 21e is lower than that of the core 21d. Therefore, the optical fiber 20 can confine light inside the core 21d.
　ブーツ６０は、図２に示すように、複数の光ファイバ２０が挿通される筒状の部材である。ブーツ６０の前端部は、フェルール１０の導入孔１４に挿入されている。これにより、ブーツ６０はフェルール１０の後端部に固定されている。ブーツ６０は、光ファイバ２０を保護する役割を有する。 As shown in FIG. 2, the boot 60 is a cylindrical member into which a plurality of optical fibers 20 are inserted. The front end of the boot 60 is inserted into the introduction hole 14 of the ferrule 10. Thereby, the boot 60 is fixed to the rear end of the ferrule 10. The boot 60 has the role of protecting the optical fiber 20.
　接着剤３０は、複数の光ファイバ２０をフェルール１０に固定する機能を有する。接着剤３０の材質としては、例えば熱硬化性樹脂を用いることができる。より具体的には、接着剤３０の材質はエポキシ樹脂であってもよい。 The adhesive 30 has the function of fixing the plurality of optical fibers 20 to the ferrule 10. As the material of the adhesive 30, for example, thermosetting resin can be used. More specifically, the material of the adhesive 30 may be epoxy resin.
　例えば高湿度環境下において、接着剤３０は吸湿し、フェルール１０の内部において膨張する場合がある。膨張した接着剤３０は、特に小径部２１ａに圧力を加え、曲げ損失を生じさせる可能性がある。特に、本実施形態においては、各小径部２１ａの少なくとも一部（後端部）は、図２に示すように、曲げが生じたまま接着剤３０に保持されている。これは、４本の小径部２１ａ同士を長手方向Ｚの全体にわたって密着させようとしても、大径部２１ｂ同士が構造的に干渉してしまうからである。そして、上記のように曲げが生じている部分には、接着剤３０の膨張に起因した応力の集中が起こりやすく、曲げ損失が生じやすい。 For example, in a high humidity environment, the adhesive 30 may absorb moisture and expand inside the ferrule 10. The expanded adhesive 30 may apply pressure particularly to the small diameter portion 21a, causing bending loss. In particular, in this embodiment, at least a portion (rear end portion) of each small diameter portion 21a is held by the adhesive 30 while being bent, as shown in FIG. This is because even if it is attempted to make the four small diameter portions 21a come into close contact with each other over the entire longitudinal direction Z, the large diameter portions 21b will structurally interfere with each other. Then, stress concentration due to the expansion of the adhesive 30 is likely to occur in the bent portion as described above, and bending loss is likely to occur.
　そこで、本実施形態の光コネクタ１Ａにおいては、注入孔１２が、接着剤３０の吸湿を抑制するための低吸湿層５０によって封止されている。低吸湿層５０は、接着剤３０よりも低い吸湿性（吸水率）を有する低吸湿性素材で形成されている。これにより、接着剤３０の吸湿に起因する光ファイバ２０の曲げ損失を抑制することができる。なお、接着剤３０の吸湿性（吸水率）は、例えば、２％程度である。この場合、低吸湿性素材の吸湿性（吸水率）は２％未満（例えば、１％以下）である。
　また、低吸湿性素材は、接着剤３０よりも低い透湿性を有していてもよい。接着剤３０の透湿性としては、例えば、吸湿係数が１．０×１０－７［ｃｃ・ｃｍ／ｃｍＨｇ・ｃｍ２・ｓ］（測定条件８５℃、８５％ＲＨ）以下である。 Therefore, in the optical connector 1A of this embodiment, the injection hole 12 is sealed with a low moisture absorption layer 50 for suppressing moisture absorption of the adhesive 30. The low moisture absorption layer 50 is formed of a low moisture absorption material that has lower moisture absorption (water absorption rate) than the adhesive 30. Thereby, bending loss of the optical fiber 20 due to moisture absorption of the adhesive 30 can be suppressed. Note that the hygroscopicity (water absorption rate) of the adhesive 30 is, for example, about 2%. In this case, the hygroscopicity (water absorption rate) of the low hygroscopic material is less than 2% (for example, 1% or less).
Further, the low moisture absorption material may have lower moisture permeability than the adhesive 30. The moisture permeability of the adhesive 30 is, for example, a moisture absorption coefficient of 1.0×10 −7 [cc·cm/cmHg·cm 2 ·s] (measurement conditions: 85° C., 85% RH).
　低吸湿層５０としての低吸湿性素材の種類は特に限定されないが、例えば、アクリル樹脂、エポキシ樹脂、ウレタン樹脂、またはシリコン樹脂等を採用することができる。
　アクリル系樹脂としては、例えば、株式会社スリーボンド社製の紫外線硬化アクリル系樹脂ＴｈｒｅｅＢｏｎｄ３０３０（吸水率０．８％）、協立化学社製の紫外線硬化アクリル系樹脂ワールドロックＮｏ.ＸＶＬ－９０Ｋ（吸水率０．２７％）、東亜工業社製の紫外線硬化アクリル系樹脂アロニックスＥＸＴ００３－１８２（吸水率０．０４％）が挙げられる。これらの樹脂は、吸水率が１％以下であるため、低吸湿層５０として好適に用いることが可能である。
　また、エポキシ系樹脂としては、例えば、新田ゼラチン社製の紫外線硬化型エポキシ樹脂であるＡＵＶ－８８００（吸水率０．４％）が挙げられ、ウレタン系樹脂としては、ＤＹＭＡＸ社製の紫外線硬化型ウレタン系樹脂である１１１－ＭＳＫ(吸水率０．６％)が挙げられ、シリコン系樹脂としては、信越化学工業社製の紫外線硬化シリコン系樹脂であるＫＲ－４７０（吸水率０．５％）が挙げられる。これらの樹脂も上述のアクリル系樹脂と同様に、吸水率が１％以下であるため、低吸湿層５０として好適に用いることが可能である。
　なお、接着剤３０が熱硬化性樹脂である場合、低吸湿層５０を形成する低吸湿性素材はＵＶ硬化型樹脂であることが好ましい。低吸湿性素材および接着剤３０の双方が熱硬化性樹脂である場合、低吸湿性素材の硬化のために加えた熱が、既に硬化した接着剤３０に悪影響を及ぼす可能性がある。低吸湿性素材をＵＶ硬化型樹脂とすることで、低吸湿性素材の硬化に熱ではなく紫外線が用いられるため、上記の可能性を回避することができる。 The type of low hygroscopic material for the low hygroscopic layer 50 is not particularly limited, but for example, acrylic resin, epoxy resin, urethane resin, silicone resin, etc. can be employed.
As the acrylic resin, for example, UV-curable acrylic resin ThreeBond 3030 (water absorption rate 0.8%) manufactured by ThreeBond Co., Ltd., UV-cured acrylic resin World Lock No. 0.27%) and ultraviolet curing acrylic resin Aronix EXT003-182 (water absorption rate 0.04%) manufactured by Toa Kogyo Co., Ltd. Since these resins have a water absorption rate of 1% or less, they can be suitably used as the low moisture absorption layer 50.
Examples of epoxy resins include AUV-8800 (water absorption rate 0.4%), which is an ultraviolet curable epoxy resin manufactured by Nitta Gelatin Co., Ltd., and examples of urethane resins include ultraviolet curable epoxy resin manufactured by DYMAX Co., Ltd. 111-MSK (water absorption rate 0.6%), which is a type urethane resin, is mentioned, and examples of silicone resin include KR-470 (water absorption rate 0.5%), which is an ultraviolet curing silicone resin manufactured by Shin-Etsu Chemical Co., Ltd. ). Since these resins also have a water absorption rate of 1% or less like the above-mentioned acrylic resins, they can be suitably used as the low moisture absorption layer 50.
Note that when the adhesive 30 is a thermosetting resin, the low hygroscopic material forming the low hygroscopic layer 50 is preferably a UV curable resin. If both the low hygroscopic material and the adhesive 30 are thermosetting resins, the heat applied to cure the low hygroscopic material may have an adverse effect on the already cured adhesive 30. By using a UV curable resin as the low hygroscopic material, the above possibility can be avoided because ultraviolet rays instead of heat are used to cure the low hygroscopic material.
　図２に示すように、本実施形態に係る低吸湿層５０の表面には、撥水層５１が設けられている。より具体的に、撥水層５１は、低吸湿層５０のうちフェルール１０の外側に向く面に設けられる。撥水層５１は、低吸湿層５０の表面を撥水加工することによって形成される層である。撥水層５１を形成する素材としては、例えば、シリコン系撥水剤またはフッ素系撥水剤等を用いることができる。ただし、低吸湿層５０の表面に撥水層５１が設けられていなくてもよい。 As shown in FIG. 2, a water-repellent layer 51 is provided on the surface of the low moisture absorption layer 50 according to this embodiment. More specifically, the water-repellent layer 51 is provided on the surface of the low moisture absorption layer 50 that faces the outside of the ferrule 10 . The water-repellent layer 51 is a layer formed by treating the surface of the low moisture absorption layer 50 to be water-repellent. As a material for forming the water-repellent layer 51, for example, a silicon-based water repellent, a fluorine-based water repellent, or the like can be used. However, the water repellent layer 51 may not be provided on the surface of the low moisture absorption layer 50.
　撥水層５１としては、その表面における水滴の接触角が１００度以上であればよい。撥水層５１としては、例えば、スリーエム社製のフッ素系コーティング剤であるＮｏｖｅｃ１７００（接触角：１０５度）、スリーボンド社製のシラン系コーティング剤であるアクリル系樹脂ＴｈｒｅｅＢｏｎｄ２９０７Ｄ（接触角：１０３度）等を採用することができる。このような撥水層５１を用いることによって、より効果的に低吸湿層５０の耐湿性を向上させることできる。 The water-repellent layer 51 may have a contact angle of water droplets on its surface of 100 degrees or more. Examples of the water-repellent layer 51 include Novec 1700 (contact angle: 105 degrees), a fluorine-based coating agent manufactured by 3M, acrylic resin ThreeBond 2907D (contact angle: 103 degrees), a silane-based coating agent manufactured by ThreeBond, etc. can be adopted. By using such a water repellent layer 51, the moisture resistance of the low moisture absorption layer 50 can be improved more effectively.
　また、図５に示すように、本実施形態に係る光コネクタ１Ａにおいては、フェルール１０の導入孔１４の内側の空間も、低吸湿性素材によって封止されている。ここで、本実施形態において「導入孔１４の内側の空間」とは、図に示す隙間Ｇ１～Ｇ３を意味する。隙間Ｇ１は、ブーツ６０の外周面と導入孔１４の内周面との間の隙間である。隙間Ｇ２は、光ファイバ２０の外周面とブーツ６０の内周面との間の隙間である。隙間Ｇ３は、４本の光ファイバ２０の外周面によって囲まれる隙間（空間）である。ただし、導入孔１４の内側の空間が低吸湿性素材によって封止されていなくてもよい。 Furthermore, as shown in FIG. 5, in the optical connector 1A according to the present embodiment, the space inside the introduction hole 14 of the ferrule 10 is also sealed with a low hygroscopic material. Here, in this embodiment, "the space inside the introduction hole 14" means the gaps G1 to G3 shown in the figure. The gap G1 is a gap between the outer peripheral surface of the boot 60 and the inner peripheral surface of the introduction hole 14. Gap G2 is a gap between the outer peripheral surface of optical fiber 20 and the inner peripheral surface of boot 60. The gap G3 is a gap (space) surrounded by the outer peripheral surfaces of the four optical fibers 20. However, the space inside the introduction hole 14 does not need to be sealed with a low hygroscopic material.
　以上説明したように、本実施形態に係る光コネクタ１Ａは、大径部２１ｂと、大径部２１ｂよりも小さい外径を有する小径部２１ａと、を有するベアファイバ２１を各々有する複数の光ファイバ２０と、ベアファイバ２１を複数挿通可能な単一の挿通孔１１と、挿通孔１１と連通する注入孔１２と、を有するフェルール１０と、複数のベアファイバ２１が挿通孔１１に挿通された状態で、複数の光ファイバ２０をフェルール１０に固定する接着剤３０と、接着剤３０よりも低い吸湿性を有する低吸湿性素材で形成され、注入孔１２を封止する低吸湿層５０と、を備える。 As described above, the optical connector 1A according to the present embodiment includes a plurality of optical fibers each having a bare fiber 21 having a large diameter portion 21b and a small diameter portion 21a having a smaller outer diameter than the large diameter portion 21b. 20, a single insertion hole 11 through which a plurality of bare fibers 21 can be inserted, and an injection hole 12 communicating with the insertion hole 11, and a state in which a plurality of bare fibers 21 are inserted into the insertion hole 11. , an adhesive 30 for fixing the plurality of optical fibers 20 to the ferrule 10, and a low hygroscopic layer 50 that is formed of a low hygroscopic material having a hygroscopicity lower than that of the adhesive 30 and seals the injection hole 12. Be prepared.
　この構成により、接着剤３０の吸湿に起因する光ファイバ２０の曲げ損失を抑制することができる。 With this configuration, bending loss of the optical fiber 20 due to moisture absorption of the adhesive 30 can be suppressed.
　また、接着剤３０は、熱硬化性樹脂であり、低吸湿性素材は、ＵＶ硬化型樹脂であってもよい。この構成によれば、低吸湿層５０の形成が接着剤３０に悪影響を及ぼしにくくなる。 Furthermore, the adhesive 30 may be a thermosetting resin, and the low hygroscopic material may be a UV curable resin. According to this configuration, the formation of the low moisture absorption layer 50 is less likely to have an adverse effect on the adhesive 30.
　また、低吸湿層５０の表面に撥水層５１が設けられていてもよい。この構成によれば、接着剤３０が吸湿する可能性をより低減し、光ファイバ２０の曲げ損失をより効果的に抑制することができる。 Additionally, a water repellent layer 51 may be provided on the surface of the low moisture absorption layer 50. According to this configuration, the possibility that the adhesive 30 absorbs moisture can be further reduced, and the bending loss of the optical fiber 20 can be suppressed more effectively.
　また、フェルール１０は、複数の光ファイバ２０を挿通孔１１に導入する、注入孔１２とは異なる導入孔１４をさらに有し、導入孔１４の内側の空間は、低吸湿性素材によって封止されていてもよい。この構成によれば、接着剤３０が吸湿する可能性をさらに低減し、光ファイバ２０の曲げ損失をより確実に抑制することができる。
　なお、本実施形態では、挿通孔１１を１つとしたが、複数の挿通孔を備えていてもよい。その場合であっても、単一の挿通孔に対して、複数の光ファイバが挿通されるように構成される。 The ferrule 10 further includes an introduction hole 14 different from the injection hole 12 for introducing the plurality of optical fibers 20 into the insertion hole 11, and the space inside the introduction hole 14 is sealed with a low hygroscopic material. You can leave it there. According to this configuration, the possibility that the adhesive 30 absorbs moisture can be further reduced, and the bending loss of the optical fiber 20 can be suppressed more reliably.
In addition, in this embodiment, the number of insertion holes 11 is one, but a plurality of insertion holes may be provided. Even in that case, the configuration is such that a plurality of optical fibers are inserted through a single insertion hole.
（第２実施形態）
　次に、第２実施形態について説明するが、第１実施形態と基本的な構成は同様である。
このため、同様の構成には同一の符号を付してその説明は省略し、異なる点についてのみ説明する。 (Second embodiment)
Next, a second embodiment will be described, which has the same basic configuration as the first embodiment.
Therefore, similar configurations will be given the same reference numerals and their explanations will be omitted, and only the different points will be explained.
　本実施形態に係る光コネクタ１Ｂでは、図６および図７に示すように、フェルール７０の構造が、第１実施形態に係るフェルール１０の構造と異なる。具体的に、本実施形態に係るフェルール７０は、別体に形成されたフェルール本体部７１およびフランジ部７２を有する。本実施形態において、フェルール本体部７１の前面がフェルール７０の接続端面７０ａであり、フランジ部７２の後面がフェルール７０の後端面７０ｂである。接続端面７０ａには、第１実施形態と同様に、挿通孔７３が開口している。図７に示すように、フランジ部７２の前面には保持孔７２ａが開口している。保持孔７２ａにフェルール本体部７１の後端部が挿入されることにより、フランジ部７２はフェルール本体部７１を保持している。 In the optical connector 1B according to the present embodiment, as shown in FIGS. 6 and 7, the structure of the ferrule 70 is different from the structure of the ferrule 10 according to the first embodiment. Specifically, the ferrule 70 according to the present embodiment includes a ferrule main body portion 71 and a flange portion 72 that are formed separately. In this embodiment, the front surface of the ferrule main body portion 71 is the connection end surface 70a of the ferrule 70, and the rear surface of the flange portion 72 is the rear end surface 70b of the ferrule 70. An insertion hole 73 is opened in the connection end surface 70a as in the first embodiment. As shown in FIG. 7, a holding hole 72a is opened in the front surface of the flange portion 72. The flange portion 72 holds the ferrule main body 71 by inserting the rear end portion of the ferrule main body 71 into the holding hole 72a.
　本実施形態において、注入孔７４はフェルール７０の後端面７０ｂに開口している。そして、光コネクタ１Ｂは、第１実施形態に係る光コネクタ１Ａと同様に、注入孔７４を封止する低吸湿層５０を備える。本実施形態に係る低吸湿層５０は、フェルール７０の後端に位置する。また、本実施形態において、光ファイバ２０は、注入孔７４を通して挿通孔７３に導入されている。つまり、本実施形態に係る注入孔７４は、第１実施形態における導入孔１４としても機能する。 In this embodiment, the injection hole 74 is open to the rear end surface 70b of the ferrule 70. The optical connector 1B includes a low moisture absorption layer 50 that seals the injection hole 74, similarly to the optical connector 1A according to the first embodiment. The low moisture absorption layer 50 according to this embodiment is located at the rear end of the ferrule 70. Further, in this embodiment, the optical fiber 20 is introduced into the insertion hole 73 through the injection hole 74. That is, the injection hole 74 according to this embodiment also functions as the introduction hole 14 in the first embodiment.
　以上説明したように、本実施形態に係る光コネクタ１Ｂにおいて、複数の光ファイバ２０は、注入孔７４を通して挿通孔７３に導入されている。この場合においても、注入孔７４を封止する低吸湿層５０を設けることにより、第１実施形態と同様に、接着剤３０の吸湿に起因する光ファイバ２０の曲げ損失を抑制することができる。 As explained above, in the optical connector 1B according to the present embodiment, the plurality of optical fibers 20 are introduced into the insertion hole 73 through the injection hole 74. Also in this case, by providing the low moisture absorption layer 50 that seals the injection hole 74, bending loss of the optical fiber 20 due to moisture absorption of the adhesive 30 can be suppressed, as in the first embodiment.
　なお、本発明の技術的範囲は前記実施形態に限定されず、本発明の趣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可能である。 Note that the technical scope of the present invention is not limited to the above embodiments, and various changes can be made without departing from the spirit of the present invention.
　例えば、第１実施形態に係る光コネクタ１Ａにおいて、低吸湿層５０は、フェルール１０と同一の素材によって形成された蓋部であってもよい。言い換えれば、低吸湿層５０を形成する低吸湿性素材は、フェルール１０の素材と同一であってもよい。このような低吸湿層５０は、例えば、フェルール１０に接着剤３０を注入した後に、注入孔１２を溶接することによって形成することができる。あるいは、フェルール１０と同一の素材によって形成された蓋体をフェルール１０とは別に用意し、当該蓋体で注入孔１２を封止してもよい。フェルール１０の素材は、例えばＰＰＳ（ポリフェニレンサルファイド）である。 For example, in the optical connector 1A according to the first embodiment, the low moisture absorption layer 50 may be a lid portion formed of the same material as the ferrule 10. In other words, the low moisture absorption material forming the low moisture absorption layer 50 may be the same as the material of the ferrule 10. Such a low moisture absorption layer 50 can be formed, for example, by injecting the adhesive 30 into the ferrule 10 and then welding the injection hole 12. Alternatively, a lid made of the same material as the ferrule 10 may be prepared separately from the ferrule 10, and the injection hole 12 may be sealed with the lid. The material of the ferrule 10 is, for example, PPS (polyphenylene sulfide).
　また、フェルール１０、７０は、複数の光ファイバ２０を挿通可能な挿通孔１１、７３を複数有していてもよい。 Further, the ferrules 10 and 70 may have a plurality of insertion holes 11 and 73 through which the plurality of optical fibers 20 can be inserted.
　その他、本発明の趣旨を逸脱しない範囲で、上記した実施形態における構成要素を周知の構成要素に置き換えることは適宜可能であり、また、上記した実施形態や変形例を適宜組み合わせてもよい。 In addition, the components in the embodiments described above can be replaced with well-known components as appropriate without departing from the spirit of the present invention, and the embodiments and modifications described above may be combined as appropriate.
　１Ａ、１Ｂ…光コネクタ　１０、７０…フェルール　１１、７３…挿通孔　１２、７４…注入孔　１４…導入孔　２０…光ファイバ　２１…ベアファイバ　２１ａ…小径部　２１ｂ…大径部　３０…接着剤　５０…低吸湿層　５１…撥水層 1A, 1B... Optical connector 10, 70... Ferrule 11, 73... Insertion hole 12, 74... Injection hole 14... Introduction hole 20... Optical fiber 21... Bare fiber 21a... Small diameter part 21b... Large diameter part 30... Adhesive 50... Low moisture absorption layer 51...Water repellent layer

Claims (6)

  1. 　大径部と、前記大径部よりも小さい外径を有する小径部と、を有するベアファイバを各々有する複数の光ファイバと、
    　複数の前記ベアファイバを挿通可能な挿通孔と、前記挿通孔と連通する注入孔と、を有するフェルールと、
    　前記複数のベアファイバが前記挿通孔に挿通された状態で、前記複数の光ファイバを前記フェルールに固定する接着剤と、
    　前記接着剤よりも低い吸湿性を有する低吸湿性素材で形成され、前記注入孔を封止する低吸湿層と、を備える、
    　光コネクタ。     a plurality of optical fibers each having a bare fiber having a large diameter portion and a small diameter portion having an outer diameter smaller than the large diameter portion;
    a ferrule having an insertion hole into which a plurality of bare fibers can be inserted, and an injection hole communicating with the insertion hole;
    an adhesive that fixes the plurality of optical fibers to the ferrule in a state where the plurality of bare fibers are inserted into the insertion holes;
    a low hygroscopic layer formed of a low hygroscopic material having lower hygroscopicity than the adhesive and sealing the injection hole;
    optical connector.
  2. 　前記接着剤は、熱硬化性樹脂であり、
    　前記低吸湿性素材は、ＵＶ硬化型樹脂である、
    　請求項１に記載の光コネクタ。     The adhesive is a thermosetting resin,
    The low hygroscopic material is a UV curable resin,
    The optical connector according to claim 1.
  3. 　前記低吸湿層の表面に撥水層が設けられている、
    　請求項１または２に記載の光コネクタ。     A water repellent layer is provided on the surface of the low moisture absorption layer.
    The optical connector according to claim 1 or 2.
  4. 　前記フェルールは、前記複数の光ファイバを前記挿通孔に導入する、前記注入孔とは異なる導入孔をさらに有し、
    　前記導入孔の内側の空間は、前記低吸湿性素材によって封止されている、
    　請求項１から３のいずれか一項に記載の光コネクタ。     The ferrule further includes an introduction hole different from the injection hole for introducing the plurality of optical fibers into the insertion hole,
    The space inside the introduction hole is sealed with the low hygroscopic material.
    The optical connector according to any one of claims 1 to 3.
  5. 　前記低吸湿性素材は、前記フェルールの素材と同一である、
    　請求項４に記載の光コネクタ。     the low hygroscopic material is the same as the material of the ferrule;
    The optical connector according to claim 4.
  6. 　前記複数の光ファイバは、前記注入孔を通して前記挿通孔に導入されている、
    　請求項１から３のいずれか一項に記載の光コネクタ。     the plurality of optical fibers are introduced into the insertion hole through the injection hole;
    The optical connector according to any one of claims 1 to 3.
PCT/JP2023/016879 2022-08-24 2023-04-28 Optical connector WO2024042781A1 (en)

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Citations (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPS53111747A (en) * 1976-12-27 1978-09-29 Western Electric Co Optical fiber connector
JP2004029710A (en) * 2002-04-30 2004-01-29 Sumitomo Electric Ind Ltd Optical module, optical connector ferrule, and method of manufacturing the same
CN103472541A (en) * 2012-06-08 2013-12-25 富士康(昆山)电脑接插件有限公司 Waveguide connector and manufacturing method thereof
JP2017187789A (en) * 2012-05-14 2017-10-12 古河電気工業株式会社 Multi-fiber optical connector
JP2019191369A (en) * 2018-04-25 2019-10-31 住友電気工業株式会社 Optical connection component and method for manufacturing optical connection component

Patent Citations (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPS53111747A (en) * 1976-12-27 1978-09-29 Western Electric Co Optical fiber connector
JP2004029710A (en) * 2002-04-30 2004-01-29 Sumitomo Electric Ind Ltd Optical module, optical connector ferrule, and method of manufacturing the same
JP2017187789A (en) * 2012-05-14 2017-10-12 古河電気工業株式会社 Multi-fiber optical connector
CN103472541A (en) * 2012-06-08 2013-12-25 富士康(昆山)电脑接插件有限公司 Waveguide connector and manufacturing method thereof
JP2019191369A (en) * 2018-04-25 2019-10-31 住友電気工業株式会社 Optical connection component and method for manufacturing optical connection component

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