Optical fiber bundle connector, and method for manufacturing an optical fiber bundle connector

Abstract

To provide an optical fiber bundle connector which can suppress bending loss and disconnection of an optical fiber.SOLUTION: An optical fiber bundle connector includes a plurality of optical fibers, a resin tube, a ferrule, an intermediate member, a frame member, and an energization member. A part of each of the plurality of optical fibers is inserted into the resin tube. The ferrule extends in a first direction. The ferrule holds the tip parts of the plurality of optical fibers. The intermediate member forms a cylindrical shape. The plurality of optical fibers are inserted into the intermediate member. The intermediate member connects the resin tube and the ferrule. The frame member stores at least a part of the ferrule, the intermediate member, and at least a part of the resin tube. The energization member is arranged in the periphery of the intermediate member. The energization member energizes the ferrule to the tip side of the plurality of optical fibers with respect to the frame member.SELECTED DRAWING: Figure 1

Description

Technical Field

[0001] The present disclosure relates to an optical fiber bundle connector and a method for manufacturing an optical fiber bundle connector.

Background Art

[0002] Patent Document 1 discloses an optical fiber bundle connector. The optical fiber bundle connector includes a plurality of optical fibers, a ferrule, a frame member, and a biasing member. The ferrule extends in a first direction. The ferrule holds the tip portions of the plurality of optical fibers. The frame member houses at least a part of the ferrule. The biasing member biases the ferrule toward the tip side of the plurality of optical fibers with respect to the frame member.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Patent Document 2

Non-Patent Documents

[0004]

Non-Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0005] In the optical fiber bundle connector disclosed in Patent Document 1, the ferrule is biased by a biasing member and moves relative to the frame member in a first direction. In this case, the optical fiber, which is not protected by a protective tube or the like, may bend, and bending loss may occur in the optical fiber. In particular, when multiple optical fibers are held in the ferrule, bending loss in the optical fiber is even more likely to occur. Bending of the optical fiber may also cause the optical fiber to break.

[0006] This disclosure aims to provide an optical fiber bundle connector that can suppress bending loss and breakage of optical fibers, and a method for manufacturing an optical fiber bundle connector. [Means for solving the problem]

[0007] The optical fiber bundle connector according to this disclosure comprises a plurality of optical fibers, a resin tube, a ferrule, an intermediate member, a frame member, and a biasing member. A portion of each of the plurality of optical fibers is inserted into the resin tube. The ferrule extends in a first direction. The ferrule holds the tip portions of the plurality of optical fibers. The intermediate member has a cylindrical shape. A plurality of optical fibers are inserted into the intermediate member. The intermediate member connects the resin tube and the ferrule. The frame member houses at least a portion of the ferrule, the intermediate member, and at least a portion of the resin tube. The biasing member is arranged around the intermediate member. The biasing member biases the ferrule toward the tip side of the plurality of optical fibers relative to the frame member.

[0008] A method for manufacturing an optical fiber bundle connector according to this disclosure includes inserting each of a plurality of optical fibers from the tip portion of the plurality of optical fibers, holding the tip portion of a resin tube in an intermediate member, connecting a ferrule to the intermediate member and arranging a biasing member around the intermediate member, housing at least a portion of the ferrule, the intermediate member and at least a portion of the resin tube in a frame member, and biasing the ferrule toward the tip side of the plurality of optical fibers relative to the frame member with the biasing member. Each of the plurality of optical fibers is partially housed in a resin tube. The intermediate member has a cylindrical shape. The ferrule extends in a first direction and holds the tip portions of the plurality of optical fibers. [Effects of the Invention]

[0009] This disclosure provides an optical fiber bundle connector that can suppress bending loss and breakage of optical fibers, and a method for manufacturing an optical fiber bundle connector. [Brief explanation of the drawing]

[0010] [Figure 1] Figure 1 is a cross-sectional view showing an optical fiber bundle connector in an embodiment. [Figure 2] Figure 2 is a cross-sectional view of the optical fiber bundle connector shown in Figure 1 along line II-II. [Figure 3] Figure 3 shows the end faces of the optical fiber and ferrule of a fiber bundle connector. [Figure 4] Figure 4 shows the manufacturing process of an optical fiber bundle connector in an embodiment. [Figure 5] Figure 5 shows the manufacturing process for optical fiber bundle connectors. [Figure 6] Figure 6 shows the manufacturing process for optical fiber bundle connectors. [Figure 7] Figure 7 shows the manufacturing process for optical fiber bundle connectors. [Figure 8]FIG. 8 is a diagram showing the manufacturing process of an optical fiber bundle connector. [Figure 9] FIG. 9 is a diagram showing the manufacturing process of an optical fiber bundle connector. [Figure 10] FIG. 10 is a diagram showing the manufacturing process of an optical fiber bundle connector.

BEST MODE FOR CARRYING OUT THE INVENTION

[0011] [Description of Embodiments of the Present Disclosure] First, the embodiments of the present disclosure will be listed and described.

[0012] (1) The optical fiber bundle connector according to the embodiment of the present disclosure includes a plurality of optical fibers, a resin tube, a ferrule, an intermediate member, a frame member, and a biasing member. A part of each of the plurality of optical fibers is inserted into the resin tube. The ferrule extends in the first direction. The ferrule holds the tip portions of the plurality of optical fibers. The intermediate member has a cylindrical shape. The plurality of optical fibers are inserted into the intermediate member. The intermediate member connects the resin tube and the ferrule. The frame member houses at least a part of the ferrule, the intermediate member, and at least a part of the resin tube. The biasing member is disposed around the intermediate member. The biasing member biases the ferrule toward the tip side of the plurality of optical fibers with respect to the frame member.

[0013] In this optical fiber bundle connector, a part of each of the plurality of optical fibers is inserted into the resin tube. The intermediate member connects the resin tube and the ferrule. The biasing member is disposed around the intermediate member. Therefore, the optical fibers are protected by the resin tube, and damage to the optical fibers can be suppressed. The resin tube can move together with the ferrule via the intermediate member. Accordingly, bending loss and disconnection of the optical fibers can be suppressed.

[0014] (2) In the fiber optic cable connector of (1) above, the ferrule may include a first end portion and a second end portion. The first end portion and the second end portion may face each other in the first direction. The first end portion may be located on the tip side of a plurality of optical fibers rather than the second end portion. The intermediate member may connect the second end portion and the tip portion of the resin tube. In this case, the resin tube can be easily arranged by the intermediate member.

[0015] (3) In the fiber optic cable connector of (2) above, the intermediate member may include a flange and a sleeve. The flange may hold the second end portion of the ferrule. The sleeve may be connected to the flange. The sleeve may hold the tip portion of the resin tube. The biasing member may include a winding spring having a first tip portion and a second tip portion. The frame member may include an engaging portion that engages with the first tip portion of the winding spring. The engaging portion may be formed in an annular shape when viewed from the first direction. The inner diameter of the engaging portion of the frame member may be larger than the maximum outer diameter of the sleeve. In this case, the entire sleeve can pass through the inside of the engaging portion of the frame member. Therefore, the fiber optic cable connector has a configuration that can be easily manufactured.

[0016] (4) In the fiber optic cable connector of (3) above, the sleeve may include a first portion and a second portion. The first portion may be connected to the flange. The second portion may hold the tip portion of the resin tube. The inner diameter of the winding spring may be larger than the maximum outer diameter of the first portion. In this case, at least the first portion can be inserted inside the winding spring. Therefore, the fiber optic cable connector has a structure in which a configuration in which the resin tube moves together with the ferrule with respect to the frame member can be easily realized.

[0017] (5) In the optical fiber bundle connector described in (4) above, the flange may include an engaging portion. The engaging portion of the flange may engage with the second tip of the coil spring. The shortest distance between the engaging portion of the frame member and the engaging portion of the flange in the first direction may be shorter than the natural length of the coil spring. The shortest distance between the engaging portion of the flange and the second portion of the sleeve in the first direction may be longer than the natural length of the coil spring. In this case, the optical fiber bundle connector has an intermediate member including a flange and a sleeve, and a structure in which a biasing member can easily be realized to bias the ferrules on the tip side of multiple optical fibers relative to the frame member.

[0018] (6) In any one of the optical fiber bundle connectors described in (3) to (5) above, the flange and the sleeve may be connected by press-fitting. In this case, the number of steps can be reduced compared to when a separate material such as adhesive is used for fixing the flange and the sleeve.

[0019] (7) In any one of the optical fiber bundle connectors described in (3) to (5) above, the flange and the sleeve may be connected by adhesive. In this case, the flange and the sleeve can be connected more securely.

[0020] (8) In any one of the optical fiber bundle connectors described in (3) to (5) above, the flange and the sleeve may be integrally molded. In this case, the number of steps for arranging the intermediate members can be reduced.

[0021] (9) In the optical fiber bundle connectors described in (1) to (8) above, the resin tube may include multiple resin tubes. Each of the multiple optical fibers may be individually inserted into each of the multiple resin tubes. In this case, since an optical fiber is inserted into each resin tube, each of the multiple optical fibers is protected by the resin tube.

[0022] (10) A method for manufacturing an optical fiber bundle connector according to an embodiment of the present disclosure includes: inserting each of a plurality of optical fibers into an intermediate member from the tip portions of the plurality of optical fibers, holding the tip portion of a resin tube in the intermediate member; connecting a ferrule to the intermediate member and arranging a biasing member around the intermediate member; housing at least a portion of the ferrule, the intermediate member and at least a portion of the resin tube in a frame member, and biasing the ferrule toward the tip side of the plurality of optical fibers relative to the frame member by the biasing member. Each of the plurality of optical fibers is partially housed in the resin tube. The intermediate member has a cylindrical shape. The ferrule extends in a first direction and holds the tip portions of the plurality of optical fibers. In an optical fiber bundle connector manufactured by the above manufacturing method, the optical fibers are protected by the resin tube, and damage to the optical fibers can be suppressed. The resin tube can move together with the ferrule via the intermediate member. Therefore, bending loss and breakage of the optical fibers can be suppressed. [Details of the embodiments of this disclosure]

[0023] Specific examples of embodiments of this disclosure will be described below with reference to the drawings. The present invention is not limited to these examples, and is intended to include all modifications within the meaning and scope of the claims, as defined by the claims. In the description of the drawings, identical elements are denoted by the same reference numerals, and redundant descriptions are omitted.

[0024] Figure 1 is a cross-sectional view showing an optical fiber bundle connector according to one embodiment. Figure 2 is a cross-sectional view of the optical fiber bundle connector shown in Figure 1 along line II-II.

[0025] As shown in Figures 1 to 3, the optical fiber bundle connector 1 comprises a plurality of optical fibers 2, a resin tube 3, a ferrule 4, an intermediate member 5, a frame member 6, a rubber boot 7, and a biasing member 8. In the optical fiber bundle connector 1, the plurality of optical fibers 2, the resin tube 3, the ferrule 4, and the intermediate member 5 are arranged to be movable in direction A relative to the frame member 6, the rubber boot 7, and the biasing member 8. In the optical fiber bundle connector 1, the plurality of optical fibers 2, the resin tube 3, the ferrule 4, and the intermediate member 5 are not fixed to the frame member 6, the rubber boot 7, and the biasing member 8, but are in a floating state. Figure 3 shows the end faces of the optical fibers and ferrules of the optical fiber bundle connector.

[0026] The optical fiber bundle connector 1 is connected to an optical fiber connector (not shown). The optical fiber connector to which the optical fiber bundle connector 1 is connected is, for example, a multifiber connector. For example, the optical fiber bundle connector 1 optically connects a plurality of optical fibers 2 to a multicore fiber (hereinafter also referred to as "MCF") in the optical fiber connector (not shown). The MCF includes, for example, a plurality of cores extending in the first direction and a cladding covering the plurality of cores. For example, the optical fiber bundle connector 1 aligns the ferrule 4 and the ferrule (not shown) that holds the MCF so that the optical axis of each core of the MCF aligns with the optical axis of each core of the plurality of optical fibers 2 when connected to the optical fiber connector (not shown). In the optical connection structure formed by the connection of the optical fiber bundle connector 1 and the optical fiber connector (not shown), at least one of the plurality of cores contained in the MCF and at least one core of the plurality of optical fibers 2 are optically coupled.

[0027] Each optical fiber 2, as shown in Figure 2, has a core 2a extending in direction A, a cladding 2b extending in direction A and covering the core 2a, and a tip surface 2c. Figure 2 shows the tips of multiple optical fibers 2 and the end face of the ferrule 4. The tip surface 2c is composed of the tip of the core 2a and the tip of the cladding 2b. The core 2a may be made of silica glass to which a dopant such as germanium has been added to increase the refractive index, and the cladding 2b may be made of silica glass to which a dopant such as fluorine has been added to lower the refractive index, and the combination of materials and dopants can be selected as appropriate. In such optical fibers 2, an optical signal of a predetermined wavelength is propagated by each core 2a. Each of the multiple optical fibers 2 is a single-core optical fiber having one core. As a modification of this embodiment, each of the multiple optical fibers 2 may be, for example, an optical fiber bundle structure including a multi-core optical fiber, or a structure in which single-core optical fibers and multi-core optical fibers are mixed.

[0028] Each optical fiber 2 is arranged in a two-dimensional manner when viewed from direction A. As shown in Figure 2, for example, multiple optical fibers 2 are four optical fibers 2. Each optical fiber 2 is, for example, a single-mode optical fiber. Each optical fiber 2 has a unimodal refractive index distribution profile. In a modified example of this embodiment, each optical fiber 2 may have a layer between the core 2a and the cladding 2b with a refractive index lower than that of the cladding 2b, and may have a trench-type refractive index distribution profile. In another modified example of this embodiment, each optical fiber 2 may be a multimode optical fiber.

[0029] The number and arrangement of cores 2a in optical fiber 2 correspond to the number and arrangement of multiple cores in the optical fiber connector connected to the optical fiber bundle connector 1. In other words, the arrangement of cores 2a in each of the multiple optical fibers 2 matches the arrangement of multiple cores in the optical fiber connector connected to the optical fiber bundle connector 1. However, the total number and arrangement of cores 2a in the multiple optical fibers 2 do not need to perfectly match the number and arrangement of multiple cores in the optical fiber connector connected to the optical fiber bundle connector 1; some may not be optically connected.

[0030] The resin tube 3 has a tubular shape and houses a portion of the optical fiber 2. The resin tube 3 is flexible. A portion of each of the multiple optical fibers 2 is inserted into the resin tube 3. For example, the resin tube 3 includes multiple resin tubes 3. The multiple resin tubes 3 may be formed integrally or may be connected as a single bundle with adhesive. The resin tube 3 includes the outer circumference 3a of one bundle. Each resin tube 3 includes through holes 31. The resin tube 3 includes multiple through holes 31 that are spaced apart from each other. Each of the multiple optical fibers 2 is individually inserted into the multiple through holes 31. At least the tip portion 2d of each optical fiber 2 is exposed from the resin tube 3.

[0031] The ferrule 4 extends in direction A. The ferrule 4 holds together the tip portions 2d of multiple optical fibers 2. For example, the ferrule 4 holds together the tip portions 2d of four optical fibers 2. For example, the ferrule 4 has a cylindrical shape. The ferrule 4 includes a pair of ends 4a and 4b. The ends 4a and 4b face each other in direction A. End 4a is located closer to the tip of the multiple optical fibers 2 than end 4b. If end 4a is the first end, then end 4b corresponds to the second end.

[0032] The ferrule 4 has an inner bore 41. The inner bore 41 corresponds to a through hole that accommodates each tip portion 2d of the multiple optical fibers 2. As shown in Figure 3, the ferrule 4 fixes each tip portion 2d of the multiple optical fibers 2 in the inner bore 41 by a resin portion 9 such that each tip surface 2c of the multiple optical fibers 2 is exposed on the inside of the end portion 4a. The inner diameter of the inner bore 41 is the same as or slightly larger than the outer diameter of the bundle of multiple optical fibers 2, and the tip portions 2d of the multiple optical fibers 2 are inserted into the inner bore 41 and bonded and fixed by the resin portion 9 that fills the gap between them. The ferrule 4 is made of, for example, a ceramic material such as zirconia or a glass material.

[0033] The resin part 9 is, for example, a wire-binding adhesive. The resin part 9 is, for example, a thermosetting adhesive, which can be cured by heating after being injected into a predetermined location. If the ferrule 4 is mainly made of ceramic material, the resin part 9 is, for example, a thermosetting epoxy adhesive or a thermosetting acrylic adhesive. If the ferrule 4 is mainly made of glass material, the resin part 9 is, for example, a thermosetting epoxy adhesive, a thermosetting acrylic adhesive, an ultraviolet-curing epoxy adhesive, or an ultraviolet-curing acrylic adhesive. The resin part 9 is not limited to, but depends on, the material of the ferrule 4.

[0034] The intermediate member 5 has a cylindrical shape. Multiple optical fibers 2 are inserted into the intermediate member 5. The intermediate member 5 connects the resin tube 3 and the ferrule 4. The intermediate member 5 connects the end 4b of the ferrule 4 and the tip portion 32 of the resin tube 3. The intermediate member 5 includes a flange 11 and a sleeve 12.

[0035] The flange 11 holds the end 4b of the ferrule 4. The flange 11 houses a portion of the multiple optical fibers 2 inside. The flange 11 has a cylindrical shape. The flange 11 holds the ferrule 4 and the multiple optical fibers 2. The end 4b of the ferrule 4 is fixed inside the flange 11, for example, by adhesive. The flange 11 is made of, for example, metal or resin.

[0036] The flange 11 includes a portion 11a and a portion 11b. Portion 11a is closer to the tip portion 2d of the optical fiber 2 than portion 11b. The maximum outer diameter of portion 11a is greater than the maximum outer diameter of portion 11b. Portion 11a of the flange 11 holds the end portion 4b of the ferrule 4. Portion 11a of the flange 11 includes an engaging portion 51. The engaging portion 51 is, for example, a step formed by the difference between the outer diameters of portion 11a and portion 11b. The engaging portion 51 of the flange 11 engages with the biasing member 8.

[0037] The sleeve 12 is connected to the flange 11. The sleeve 12 holds the tip portion 32 of the resin tube 3. The sleeve 12 houses a portion of a plurality of optical fibers 2 inside. The sleeve 12 has a cylindrical shape. The sleeve 12 holds the resin tube 3 and the plurality of optical fibers 2. The tip portion 32 of the resin tube 3 is fixed inside the sleeve 12, for example, by adhesive. The tip portion 32 of the resin tube 3 may also be fixed inside the sleeve 12, for example, by press-fitting. The sleeve 12 is made of, for example, metal or resin.

[0038] The sleeve 12 includes portions 12a and 12b. Portion 12a is closer to the tip portion 2d of the optical fiber 2 than portion 12b. The maximum outer diameter of portion 12b is greater than the maximum outer diameter of portion 12a. The sleeve 12 includes a step 13c formed by the difference between the outer diameters of portion 12b and portion 12a. Portion 12a is connected to portion 11b of the flange 11. Portion 12b holds the tip portion 32 of the resin tube 3. Portion 11b of the flange 11 and portion 12a of the sleeve 12 are connected, for example, by press-fitting. In a variation of this embodiment, portion 11b of the flange 11 and portion 12a of the sleeve 12 may be connected by adhesive. The flange 11 and the sleeve 12 may be integrally molded.

[0039] The frame member 6 has a cylindrical shape. Multiple optical fibers 2, a resin tube 3, a ferrule 4, an intermediate member 5, and a biasing member 8 are inserted into the frame member 6. The frame member 6 houses at least a portion of the ferrule 4, the intermediate member 5, and a portion of the resin tube 3. The frame member 6 includes a plug frame 61 and a stopper 62. The plug frame 61 and the stopper 62 are connected to each other, for example, by adhesive. The plug frame 61 houses a portion of the ferrule 4, a portion of the intermediate member 5, and a portion of the biasing member 8. The ferrule 4 protrudes from the plug frame 61. The stopper 62 houses a portion of the ferrule 4, a portion of the intermediate member 5, a portion of the biasing member 8, and a portion of the resin tube 3.

[0040] The stopper 62 includes engaging portions 63 and 64. The engaging portion 63 protrudes, for example, in a direction toward the optical fiber 2. The engaging portion 63 engages with the biasing member 8. The engaging portion 63 is formed in an annular shape when viewed from direction A. The inner diameter of the engaging portion 63 is larger than the maximum outer diameter of the sleeve 12. The engaging portion 64 protrudes, for example, in a direction toward the optical fiber 2. The engaging portion 64 engages with the rubber boot 7.

[0041] The rubber boot 7, for example, has a tubular shape and houses parts of multiple optical fibers 2, resin tubes 3, and a part of the stopper 62. The rubber boot 7 is flexible. The rubber boot 7 includes a tip portion 7a and a tip portion 7b. Tip portion 7a is connected to the stopper 62. For example, tip portion 7a is fixed to the engaging portion 64 of the stopper 62 by adhesive. Tip portion 7b is in contact with the outer circumference 3a of the bundle of multiple resin tubes 3. For example, tip portion 7b slides against the outer circumference 3a in response to an external force.

[0042] The biasing member 8 is positioned around the intermediate member 5. The biasing member 8 biases the ferrules 4 to the tip ends of the multiple optical fibers 2 relative to the frame member 6. The biasing member 8 includes a coil spring having a pair of tip portions 8a and 8b. If tip portion 8b corresponds to the first tip portion, tip portion 8a corresponds to the second tip portion. Hereinafter, the biasing member 8 will also be referred to as the "coil spring 8". The coil spring 8 is spirally formed along the outer circumference of portion 11b of the flange 11 and the outer circumference of portion 12a of the sleeve 12. In other words, portion 11b of the flange 11 and portion 12a of the sleeve 12 are inserted inside the coil spring 8.

[0043] The inner diameter of the coil spring 8 is larger than the maximum outer diameter of portion 11b of the flange 11 and the maximum outer diameter of portion 12a of the sleeve 12. The inner diameter of the coil spring 8 is smaller than the maximum outer diameter of portion 11a of the flange 11. The inner diameter of the coil spring 8 is larger than the inner diameter of the engaging portion 63 of the frame member 6.

[0044] The tip portion 8a engages with the engaging portion 51 of the flange 11. In the example of this embodiment, the tip portion 8a is in contact with the engaging portion 51. In a modified version of this embodiment, the tip portion 8a may engage with the engaging portion 51 via another member such as a washer. In this modified version, the tip portion 8a is in contact with the washer, and the washer is in contact with the engaging portion 51.

[0045] The tip portion 8b engages with the engaging portion 63 of the frame member 6. In the example of this embodiment, the tip portion 8b is in contact with the engaging portion 63. In a modified example of this embodiment, the tip portion 8b may engage with the engaging portion 63 via another member such as a washer. The washer is placed between the tip portion 8b of the coil spring 8 and the engaging portion 63 of the frame member 6. In this modified example, the tip portion 8b is in contact with the washer, and the washer is in contact with the engaging portion 63. In this case, even if the inner diameter of the engaging portion 63 is enlarged, the contact area for the tip portion 8b of the coil spring 8 is secured. Therefore, the inner diameter of the engaging portion 63 can be enlarged while the frame member 6 as a whole is made more compact.

[0046] The shortest distance L1 between the engaging portion 51 of the flange 11 and the engaging portion 63 of the frame member 6 in direction A is, for example, shorter than the natural length of the coil spring 8. The shortest distance L2 between the engaging portion 51 of the flange 11 and portion 12b of the sleeve 12 in direction A may be longer than the natural length of the coil spring 8. The shortest distance L2 corresponds to the shortest distance between the engaging portion 51 of the flange 11 and portion 12c of the sleeve 12 in direction A.

[0047] Next, the manufacturing method of the optical fiber bundle connector 1 will be described with reference to Figures 4 to 10. Figures 4 to 10 each show the manufacturing process of the optical fiber bundle connector.

[0048] First, as shown in Figure 4, each of the multiple optical fibers 2 is inserted into a resin tube 3. The optical fiber 2 includes a coating portion 2e. The tip portion 2d of the optical fiber 2 has the coating portion 2e removed and is further reduced in diameter compared to a typical outer diameter. For example, the tip portion 2d is formed by diameter reduction processing using etching with hydrofluoric acid solution or the like. At least a portion of the optical fiber 2 that is covered by the coating portion 2e is housed in each resin tube 3. The multiple resin tubes 3 are connected in a bundle. The bundle of multiple resin tubes 3 includes an outer circumference 3a.

[0049] Next, as shown in Figure 5, each of the multiple optical fibers 2 is inserted into the sleeve 12 of the intermediate member 5 from its tip portion 2d, and the tip portion 32 of the resin tube 3 is held by the intermediate member 5. The tip portions 2d of the multiple optical fibers 2 penetrate the sleeve 12 and protrude from portion 12a. The tip portion 32 of the resin tube 3 is fixed in portion 12b of the sleeve 12.

[0050] Next, as shown in Figure 6, the coil springs 8 are placed on the multiple optical fibers 2 and the portion 12a of the sleeve 12. At this time, the multiple optical fibers 2 and the portion 12a of the sleeve 12 are inserted into the inside of the coil springs 8 from the tip portion 2d of the optical fiber 2.

[0051] Next, as shown in Figure 7, the tip portions 2d of multiple optical fibers 2 are inserted into the ferrule 4 and flange 11. The ferrule 4 is held by portion 11a of the flange 11. Portion 11b of the flange 11 is inserted inside the coil spring 8. As a result, the ferrule 4 is connected to the intermediate member 5, and the coil spring 8 is positioned around the intermediate member 5. The ferrule 4 extends in direction A and holds the tips of multiple optical fibers 2.

[0052] Next, as shown in Figures 8 and 9, with the rubber boot 7 held in place by the engaging portion 64 of the stopper 62, a portion of the intermediate member 5 and a portion of the resin tube 3 are inserted into the interior of the stopper 62. At this time, the stopper 62 is moved in direction β, and the tip portion 7b of the rubber boot 7 slides along the outer circumference 3a of the resin tube 3. The portion 12b of the sleeve 12 passes inside the engaging portion 63 of the stopper 62. The tip portion 8b of the coil spring 8 contacts a portion of the contact surface 63a of the engaging portion 63. The contact surface 63a is an annular surface that follows the outer shape of the engaging portion 63.

[0053] Next, as shown in Figure 10, the plug frame 61 is positioned from the tip end of the multiple optical fibers 2. The ferrule 4 and the tip portions 2d of the multiple optical fibers 2 are inserted into the plug frame 61. As a result, at least a portion of the ferrule 4, the intermediate member 5, and at least a portion of the resin tube 3 are housed in the frame member 6, and the ferrule 4 is biased toward the tip end of the multiple optical fibers 2 relative to the frame member 6 by the coil spring 8. The optical fiber bundle connector 1 is thus manufactured.

[0054] The manufacturing process for the optical fiber bundle connector 1 is not limited to the steps shown in Figures 4 to 10 and their order. For example, before the coil spring 8 is positioned, a portion of the intermediate member 5 and a portion of the resin tube 3 may be inserted into the stopper 62. Before the flange 11 and sleeve 12 are fixed, washers that abut the tips 8a and 8b of the coil spring 8 may be positioned together with the coil spring 8.

[0055] The coil spring 8 may be inserted together with the stopper 62 from the portion 12b side of the sleeve 12. In this case, the inner diameter of the coil spring 8 is configured to be larger than the maximum diameter of portion 12a of the sleeve 12. Furthermore, if the inner diameter of the engaging portion 63 is larger than the maximum outer diameter of the flange 11, the coil spring 8 can be positioned around the intermediate member 5 even when the flange 11 and the sleeve 12 are formed integrally, thereby forming the optical fiber bundle connector 1.

[0056] Next, the effects and advantages of the optical fiber bundle connector 1 and the manufacturing method of the optical fiber bundle connector 1 will be explained.

[0057] In the optical fiber bundle connector 1, a portion of each of the multiple optical fibers 2 is inserted into a resin tube 3. An intermediate member 5 connects the resin tube 3 and the ferrule 4. A biasing member 8 is positioned around the intermediate member 5. Therefore, the optical fibers 2 are protected by the resin tube 3, and damage to the optical fibers 2 can be suppressed. The resin tube 3 can move together with the ferrule 4 via the intermediate member 5. Thus, bending loss and breakage of the optical fibers 2 can be suppressed. Even in configurations using multiple optical fibers 2, a configuration in which the resin tube 3 can move together with the ferrule 4 can be easily realized.

[0058] In the optical fiber bundle connector 1, the end 4a of the ferrule 4 is located closer to the tip of the multiple optical fibers 2 than the end 4b. The intermediate member 5 connects the end 4b to the tip portion 32 of the resin tube 3. In this case, the intermediate member 5 allows the resin tube 3 to be easily positioned.

[0059] In the optical fiber bundle connector 1, the flange 11 holds the end 4b of the ferrule 4. The sleeve 12 is connected to the flange 11. The sleeve 12 holds the tip portion 32 of the resin tube 3. The frame member 6 may include an engaging portion 63 that engages with the tip portion 8b of the coil spring 8. The engaging portion 63 is formed in an annular shape when viewed from direction A. The inner diameter of the engaging portion 63 of the frame member 6 is larger than the maximum outer diameter of the sleeve 12. In this case, the entire sleeve 12 can pass inside the engaging portion 63 of the frame member 6.

[0060] In the optical fiber bundle connector 1, portion 12a of the sleeve 12 is connected to the flange 11. Portion 12b of the sleeve 12 holds the tip portion 32 of the resin tube 3. The inner diameter of the coil spring 8 is larger than the maximum outer diameter of portion 12a. In this case, at least portion 12a can be inserted inside the coil spring 8. Therefore, the optical fiber bundle connector 1 has a structure that easily enables a configuration in which the resin tube 3 moves together with the ferrule 4 relative to the frame member 6.

[0061] In the optical fiber bundle connector 1, the engaging portion 51 of the flange 11 engages with the tip portion 8a of the coil spring 8. The shortest distance L1 between the engaging portion 53 of the frame member 6 and the engaging portion 51 of the flange 11 in direction A is shorter than the natural length of the coil spring 8. The shortest distance L2 between the engaging portion 51 of the flange 11 and the portion 12b of the sleeve 12 in direction A is longer than the natural length of the coil spring 8. In this case, the optical fiber bundle connector 1 has an intermediate member 5 including the flange 11 and the sleeve 12, and has a structure that can easily realize a configuration in which the biasing member 8 biases the ferrules 4 toward the frame member 6 toward the tip side of the multiple optical fibers 2.

[0062] In the optical fiber bundle connector 1, the flange 11 and the sleeve 12 may be connected by press-fitting. In this case, the number of steps in connecting the flange 11 and the sleeve 12 can be reduced compared to when a separate material such as adhesive is used. The flange 11 and the sleeve 12 may be connected by adhesive. In this case, the flange 11 and the sleeve 12 can be connected more firmly. The flange 11 and the sleeve 12 may be integrally molded. In this case, the number of steps in arranging the intermediate member 5 can be reduced.

[0063] In the optical fiber bundle connector 1, the resin tube 3 includes multiple resin tubes 3. Each of the multiple optical fibers 2 is individually inserted into each of the multiple resin tubes 3. In this case, since an optical fiber 2 is inserted into each resin tube 3, each of the multiple optical fibers 2 is protected by the resin tube 3.

[0064] Although embodiments of the present disclosure have been described in detail above, the present invention is not limited to the above embodiments and can be applied to various embodiments. For example, a configuration in which the ferrule 4 holds four optical fibers 2 has been shown. However, the number of optical fibers 2 held by the ferrule 4 is not limited to this. For example, the ferrule 4 may hold three optical fibers 2, seven optical fibers 2, eight optical fibers 2, or nineteen optical fibers 2.

[0065] In this explanation, a multicore fiber connector containing an MCF was used as an example of the optical fiber connector to which the optical fiber bundle connector 1 is connected. However, the optical fiber connector to which the optical fiber bundle connector 1 is connected may also be an optical fiber connector having the same configuration as the optical fiber bundle connector 1. [Explanation of symbols]

[0066] 1… Fiber optic bundle connector 2… Fiber optic 2a... Core 2b... Clad 2c…Tip surface 2d,7a,7b,32...Tip part 2e...covering part 3… Resin tube 3a...Outer circumference 4…Ferrule 4a,4b...ends 5…Intermediate member 6…Frame components 7... Rubber boots 8... Coil spring, biasing member 8a, 8b…Tip 9… Resin part 11… Flange 11a,11b...part 12... Sleeves 12a, 12b, 12c...part 13c... step 31…Through hole 32...Tip part 41…Internal bore 51, 53…Engaging parts 61... Plug frame 62... Stopper 63...Engaging part 63a…Abutment surface 64...Engaging part A,β…direction L1,L2…Shortest distance

Claims

1. Multiple optical fibers, A resin tube into which a portion of each of the aforementioned multiple optical fibers is inserted, A ferrule that extends in the first direction and holds the tip portions of the plurality of optical fibers, It has a cylindrical shape, and the intermediate member has the plurality of optical fibers inserted into it and connects the resin tube and the ferrule, A frame member that houses at least a portion of the ferrule, the intermediate member, and at least a portion of the resin tube, The system includes a biasing member that is arranged around the intermediate member and biases the ferrules toward the tip side of the plurality of optical fibers relative to the frame member, An optical fiber bundle connector in which the plurality of optical fibers, the resin tube, the ferrule, and the intermediate member are in a floating state relative to the frame member and the biasing member.

2. The ferrule includes a first end and a second end that face each other in the first direction, The first end is located closer to the tip of the plurality of optical fibers than the second end, The optical fiber bundle connector according to claim 1, wherein the intermediate member connects the second end and the tip of the resin tube.

3. The intermediate member includes a flange that holds the second end of the ferrule and a sleeve that is connected to the flange and holds the tip of the resin tube. The biasing member includes a coil spring having a first tip and a second tip, The frame member is formed in an annular shape when viewed from the first direction and includes an engaging portion that engages with the first tip of the coil spring. The optical fiber bundle connector according to claim 2, wherein the inner diameter of the engaging portion of the frame member is larger than the maximum outer diameter of the sleeve.

4. The sleeve includes a first portion connected to the flange and a second portion holding the tip of the resin tube. The optical fiber bundle connector according to claim 3, wherein the inner diameter of the coil spring is larger than the maximum outer diameter of the first portion.

5. The flange includes an engaging portion that engages with the second tip of the coil spring, The shortest distance between the engaging portion of the frame member and the engaging portion of the flange in the first direction is shorter than the natural length of the coil spring. The optical fiber bundle connector according to claim 4, wherein the shortest distance between the engagement portion of the flange and the second portion of the sleeve in the first direction is longer than the natural length of the coil spring.

6. The optical fiber bundle connector according to any one of claims 3 to 5, wherein the flange and the sleeve are connected by press-fitting.

7. The optical fiber bundle connector according to any one of claims 3 to 5, wherein the flange and the sleeve are connected by an adhesive.

8. The optical fiber bundle connector according to any one of claims 3 to 5, wherein the flange and the sleeve are integrally molded.

9. The optical fiber bundle connector according to any one of claims 1 to 5, wherein the resin tube includes a plurality of resin tubes into which each of the plurality of optical fibers is individually inserted.

10. Each of the multiple optical fibers, partly housed in a resin tube, is inserted into a cylindrical intermediate member from the tip portion of the multiple optical fibers, and the tip portion of the resin tube is held by the intermediate member. A ferrule extending in the first direction and holding the tips of the plurality of optical fibers is connected to the intermediate member, and a biasing member is arranged around the intermediate member, A method for manufacturing an optical fiber band connector, comprising housing at least a portion of the ferrule, the intermediate member, and at least a portion of the resin tube in a frame member, and biasing the ferrule toward the tip side of the plurality of optical fibers relative to the frame member by the biasing member.

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