Fiber optic cables and cables with connectors

Abstract

This optical fiber cable comprises a plurality of optical fiber ribbons and a sheath covering the periphery of the plurality of optical fiber ribbons. Each optical fiber ribbon has a plurality of optical fiber core wires, the plurality of optical fiber core wires are arranged in parallel in a direction orthogonal to the lengthwise direction thereof, and connected sections in which adjacent optical core wires are connected and non-connected sections in which adjacent optical fiber core wires are not connected are provided intermittently between some or all of the optical fiber core wires in the lengthwise direction of the optical fiber core wires. Each optical fiber core wire includes a glass fiber and a cover section covering the periphery of the glass fiber. The ratio of the inner diameter to the outer diameter of the sheath is at least 0.75. The ratio of the area of the glass in a cross section accommodated in an optical fiber ribbon accommodation section with respect to the area of the optical fiber ribbon accommodation section inside the sheath in a cross section orthogonal to the lengthwise direction of an optical fiber cable is 15-25%. The number of optical fiber core wires installed within the optical fiber cable is 3000 or more. The outer diameter of the sheath is 50 mm or less.

Description

[Technical field]

[0001] The present disclosure relates to fiber optic cables and connectorized cables.

[0002] This application claims priority to Japanese Application No. 2020-178870, filed on October 26, 2020, and incorporates by reference all of the contents of said Japanese application. [Background technology]

[0003] Patent Document 1 discloses an optical fiber cable having an optical fiber ribbon in which a plurality of optical fiber cores are intermittently connected, and a pipe that accommodates the optical fiber ribbon.

[0004] Patent Document 2 discloses an optical fiber cable having an optical fiber cable core formed by twisting together multiple ribbon units each made of an optical fiber ribbon in which multiple optical fiber cores are intermittently connected, and an outer sheath covering the outer periphery of the optical fiber cable core.

[0005] Patent Document 3 discloses an optical fiber cable having a cable core portion formed by twisting together a plurality of units each having a plurality of optical fiber ribbons in which a plurality of optical fiber cores are intermittently connected, and an outer sheath covering the outer periphery of the cable core portion. [Prior art documents] [Patent documents]

[0006] [Patent Document 1] Japan Special Publication No. 2015-517679 [Patent Document 2] Japanese Patent Application Publication No. 2014-016529 [Patent Document 3] Japanese Patent Publication No. 2010-008923 Summary of the Invention [Means for solving the problem]

[0007] The optical fiber cable of the present disclosure comprises: A plurality of optical fiber ribbons; a jacket covering the periphery of the plurality of optical fiber ribbons; It is equipped with The optical fiber ribbon has a plurality of optical fiber core wires, and the plurality of optical fiber core wires are arranged in parallel in a direction perpendicular to the longitudinal direction, and among some or all of the optical fiber core wires, connected portions in which adjacent optical fiber core wires are connected and non-connected portions in which adjacent optical fiber core wires are not connected are intermittently provided in the longitudinal direction of the optical fiber core wires, The optical fiber core includes a glass fiber and a coating portion that covers the glass fiber, The ratio of the inner diameter to the outer diameter of the outer jacket is 0.75 or more, A ratio of an area of ​​the glass accommodated in the optical fiber ribbon accommodating portion to an area of ​​the optical fiber ribbon accommodating portion inside the jacket in a cross section perpendicular to the longitudinal direction of the optical fiber cable is 15% or more and 25% or less, The number of the optical fiber cores mounted in the optical fiber cable is 3000 or more, and the outer diameter of the jacket is 50 mm or less. the law of nature, The ratio of the area of ​​the optical fiber ribbon accommodated in the optical fiber ribbon accommodating portion in the cross section to the area of ​​the optical fiber ribbon accommodating portion inside the jacket in the cross section is 50% or more and 65% or less. It is.

[0008] The connectorized cable of the present disclosure further comprises: The optical fiber cable; and a multi-fiber connector provided at one end of at least one of the optical fiber ribbons of the optical fiber cable. [Brief description of the drawings]

[0009] [Figure 1A] FIG. 1A is a cross-sectional view perpendicular to the longitudinal direction of the optical fiber cable according to the first embodiment. [Figure 1B]FIG. 1B is a cross-sectional view showing the optical fiber unit of FIG. 1A. [Diagram 2] FIG. 2 is a cross-sectional view perpendicular to the longitudinal direction of the optical fiber ribbon. [Diagram 3] FIG. 3 is a partial development view showing the optical fiber ribbon shown in FIG. 2 in the longitudinal direction. [Figure 4] FIG. 4 is a cross-sectional view showing a modified example of the optical fiber unit. [Figure 5A] FIG. 5A is a cross-sectional view perpendicular to the longitudinal direction of an optical fiber cable according to a second embodiment. [Figure 5B] FIG. 5B is a cross-sectional view showing the optical fiber unit of FIG. 5A. [Figure 6] FIG. 6 is a perspective view that typically shows a state in which the optical fiber unit shown in FIG. 1B and FIG. 4 has been terminated. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0010] [Problem that this disclosure aims to solve] The present disclosure provides an optical fiber cable and a cable with connector that are capable of mounting optical fiber cores at a high density and have resistance to lateral pressure. [Effects of this disclosure] According to the present disclosure, it is possible to provide an optical fiber cable and a cable with connector that are capable of mounting optical fiber cores at a high density and have resistance to lateral pressure. [Description of the embodiment of the present disclosure] First, embodiments of the present disclosure will be listed and described. (1) The optical fiber cable of the present disclosure is A plurality of optical fiber ribbons; a jacket covering the periphery of the plurality of optical fiber ribbons; It is equipped with The optical fiber ribbon has a plurality of optical fiber core wires, and the plurality of optical fiber core wires are arranged in parallel in a direction perpendicular to the longitudinal direction, and among some or all of the optical fiber core wires, connected portions in which adjacent optical fiber core wires are connected and non-connected portions in which adjacent optical fiber core wires are not connected are intermittently provided in the longitudinal direction of the optical fiber core wires, The optical fiber core includes a glass fiber and a coating portion that covers the glass fiber, The ratio of the inner diameter to the outer diameter of the outer jacket is 0.75 or more, A ratio of an area of ​​the glass accommodated in the optical fiber ribbon accommodating portion to an area of ​​the optical fiber ribbon accommodating portion inside the jacket in a cross section perpendicular to the longitudinal direction of the optical fiber cable is 15% or more and 25% or less, The number of the optical fiber cores mounted in the optical fiber cable is 3000 or more, and the outer diameter of the jacket is 50 mm or less.

[0011] According to this configuration, the ratio of the inner diameter to the outer diameter of the jacket is 0.75 or more, so that more optical fiber cores can be arranged inside the jacket. In addition, the ratio of the area of ​​the glass in the cross section accommodated in the optical fiber ribbon accommodating section to the area of ​​the optical fiber ribbon accommodating section inside the jacket in the cross section perpendicular to the longitudinal direction of the optical fiber cable is 15% to 25%, so that the optical fiber cable can withstand the tension applied to the optical fiber cable. Note that the "optical fiber ribbon accommodating section" refers to the space inside the jacket of the optical fiber cable, excluding the holding winding tape, and the "glass accommodated in the optical fiber ribbon accommodating section" may include, for example, glass fibers constituting the optical fiber cores and glass fiber reinforced plastics (GFRP: Glass Fiber Reinforced Practices) arranged as a tension member in the optical fiber cable. Note that the case where the tension member arranged in the optical fiber ribbon accommodating section is made of metal instead of glass is not covered. In addition, since the number of optical fiber cores is 3000 or more, even if the thickness of the jacket is thin, the optical fiber cores packed in the optical fiber cable at high density can prevent the optical fiber cable from being crushed or kinked, even if lateral pressure is applied to the optical fiber cable. In addition, since the glass fiber of the optical fiber core itself functions as a tension member, even if the size of the tension member arranged in the optical fiber cable is reduced, it can withstand the tension applied to the optical fiber cable, and more optical fiber cores can be arranged. Therefore, it is possible to provide an optical fiber cable that can pack optical fiber cores at high density and has lateral pressure resistance.

[0012] (2) The ratio of the area of ​​the optical fiber ribbon accommodated in the optical fiber ribbon accommodating portion in the cross section to the area of ​​the optical fiber ribbon accommodating portion inside the jacket in the cross section may be 50% or more and 65% or less.

[0013] With this configuration, even if lateral pressure is applied to the optical fiber cable, the optical fiber cable can be prevented from being crushed because the optical fiber cores that make up the optical fiber ribbon are packed at a high density.

[0014] (3) a first pressing member for covering a periphery of a part of the plurality of optical fiber ribbons; The optical fiber ribbon may further include a second pressing member that is arranged outside the first pressing member and that covers the remaining optical fiber ribbons of the plurality of optical fiber ribbons.

[0015] According to this configuration, it is possible to easily distinguish between the optical fiber ribbon present inside the first pressing member and the optical fiber ribbon disposed outside the first pressing member.

[0016] (4) The dynamic friction coefficient between the first holding member and the optical fiber ribbon arranged outside the first holding member may be 0.3 or less, and the dynamic friction coefficient between the second holding member and the optical fiber ribbon arranged inside the second holding member may be 0.3 or less.

[0017] The optical fiber ribbon mounted in the optical fiber cable is likely to move in the longitudinal direction due to thermal contraction in a low temperature environment. With this configuration, even if thermal contraction occurs, the optical fiber ribbon is likely to move, so that an increase in transmission loss in a low temperature environment can be suppressed.

[0018] (5) The optical fiber cable may comprise a plurality of assemblies each including at least a portion of the plurality of optical fiber ribbons bundled together.

[0019] With this configuration, it becomes easier to identify and handle the optical fiber ribbons within the optical fiber cable.

[0020] (6) The device has a plurality of tubes each having a thickness of 0.01 mm or more and 0.2 mm or less, The tube may be formed to surround the assembly.

[0021] According to such a configuration, for example, by making each tube have a different color, it becomes easy to distinguish the optical fiber units in the optical fiber cable. In addition, when storing the optical fiber ribbon of the optical fiber cable in an optical connection box, closure, etc., there is no need to cover the optical fiber ribbon exposed after removing the jacket with a protective tube, improving workability. In addition, since the thickness of the tube is thin, it is possible to suppress a reduction in the space in which the optical fiber ribbon can be installed due to the placement of the tube.

[0022] (7) At least one tension member is provided, The plurality of optical fiber ribbons may be wound around the tension member in a multi-layer structure with the tension member as a center.

[0023] With this configuration, the tension member is positioned approximately at the center of the multiple optical fiber ribbons, so that the optical fiber cable is not easily bent in only a particular direction, but can be bent in all directions with the same force.

[0024] (8) The connectorized cable of the present disclosure comprises: The optical fiber cable; and a multi-fiber connector provided at one end of at least one of the optical fiber ribbons of the optical fiber cable.

[0025] With this configuration, the optical fiber cable can be easily connected to other communication components.

[0026] [Details of the embodiment of the present disclosure] Specific examples of the optical fiber cable and the cable with connector of the present disclosure will be described with reference to the drawings. Note that the present disclosure is not limited to these examples, but is defined by the claims, and is intended to include all modifications within the meaning and scope of the claims.

[0027] First embodiment The configuration of an optical fiber cable 1 according to a first embodiment will be described with reference to Fig. 1A to Fig. 3. In Fig. 1A, the optical fiber unit 2 is hatched to omit its internal configuration, and the omitted internal structure of the optical fiber unit 2 is illustrated in Fig. 1B. The circular frame shown by the dashed line in Fig. 1A and Fig. 1B shows the area of ​​the optical fiber unit 2 for the sake of convenience, and in reality, no frame exists.

[0028] 1A, the optical fiber cable 1 includes a plurality of optical fiber units 2 and an outer jacket 3. In this example, 32 optical fiber units 2 are mounted inside the outer jacket 3.

[0029] 1B, the optical fiber unit 2 has a plurality of optical fiber ribbons 21. In this example, the optical fiber unit 2 is formed by an assembly of 18 bundled optical fiber ribbons 21. The 18 optical fiber ribbons 21 forming the assembly may be twisted together.

[0030] 2 and 3, the optical fiber ribbon 21 has a plurality of optical fiber cores 211 and ribbon resin 212. In Fig. 2 and Fig. 3, the optical fiber ribbon 21 is shown in a state in which the non-connected portions 214 are spread out in the parallel direction of the optical fiber cores 211. The multiple optical fiber cores 211 are arranged in parallel in a direction perpendicular to the longitudinal direction. The ribbon resin 212 is formed so as to integrate the multiple optical fiber cores 211. In this example, 12 optical fiber cores 211 are arranged in parallel in a state of contact with each other, and the ribbon resin 212 is formed so as to cover the outer circumference of the multiple optical fiber cores 211 arranged in parallel. The ribbon resin 212 may be applied only to one side of the multiple optical fiber cores 211 arranged in parallel. The ribbon resin 212 is made of a resin such as an ultraviolet-curable resin or a thermosetting resin.

[0031] The optical fiber core 211 has, for example, a glass fiber 211a consisting of a core and a clad, and a coating portion 211b that covers the periphery of the glass fiber 211a. The coating portion 211b is formed of one or more coating layers made of a resin such as an ultraviolet curing resin. For example, an optical fiber core is used as the optical fiber core 211, in which the diameter R1 of the glass fiber 211a is 125 μm, and the diameter R2 of the optical fiber core 211 is 200 μm.

[0032] 3, at least between some adjacent optical fiber cores 211 of the optical fiber ribbon 21, connecting portions 213 where the adjacent optical fiber cores 211 are connected, and non-connecting portions 214 where the adjacent optical fiber cores 211 are not connected are intermittently provided in the longitudinal direction of the optical fiber cores 211. In this example, the connecting portions 213 and the non-connecting portions 214 are provided intermittently in the longitudinal direction of the optical fiber cores 211 for every two cores. The non-connecting portions 214 are formed, for example, by cutting a part of the ribbon resin 212 with a rotary blade or the like.

[0033] The ribbon resin 212 can also be formed by applying it between the optical fiber cores 211, rather than around the outer periphery of the parallelly arranged optical fiber cores 211. By applying the ribbon resin 212 between predetermined spaces between the optical fiber cores 211, connecting portions 213 and non-connecting portions 214 are provided intermittently, and the optical fiber cores 211 are integrated in a parallel state.

[0034] 1A is formed so as to cover the periphery of the multiple optical fiber units 2. The jacket 3 is formed, for example, from a resin having a Young's modulus of 1500 MPa or more at room temperature (for example, 23°C). A tear cord 4 and multiple tension members 5 may be embedded in the jacket 3. The tension members 5 are formed, for example, from fiber reinforced plastic (FRP) such as aramid FRP, glass FRP, or carbon FRP, or from metal wires.

[0035] The optical fiber cable 1 may further have a pressing member that covers the periphery of the optical fiber unit 2, as exemplified in FIG. 1A. In this example, the optical fiber cable 1 has a first pressing member 6 and a second pressing member 7. The first pressing member 6 and the second pressing member 7 are formed of, for example, nonwoven fabric made of polyester or the like. The first pressing member 6 is, for example, vertically attached or spirally wound around the periphery of the multiple optical fiber units 2 arranged at the center of the cable. The second pressing member 7 is, for example, vertically attached or spirally wound around the periphery of the multiple optical fiber units 2 arranged around the first pressing member 6. Note that, "vertically attached and wound" means a state in which the pressing member is wound around the optical fiber unit 2 so that the longitudinal direction of the pressing member is parallel to the longitudinal direction of the optical fiber cable 1 and the width direction of the pressing member is along the circumferential direction of the optical fiber cable 1.

[0036] In the optical fiber cable 1 configured in this manner, the jacket 3 is formed so that the ratio of the inner diameter ID to the outer diameter OD (ID / OD) is 0.75 or more. For example, if the optical fiber cable 1 in Fig. 1A is manufactured with the outer diameter OD of the jacket 3 being 29.6 mm and the inner diameter ID of the jacket 3 being 24.8 mm, the ratio of the inner diameter ID to the outer diameter OD is approximately 0.84.

[0037] Moreover, 3000 or more optical fiber cores 211 are mounted in the optical fiber cable 1. For example, 6912 optical fiber cores 211 are mounted in the optical fiber cable 1 of FIG.

[0038] The optical fiber cable 1 is configured so that the ratio of the cross-sectional area of ​​the glass accommodated in the optical fiber ribbon accommodating section S1 to the cross-sectional area of ​​the optical fiber ribbon accommodating section S1 inside the jacket 3 is 15% or more and 25% or less. The cross-sectional area is the area in a cross section perpendicular to the longitudinal direction of the optical fiber cable 1. In this example, the glass accommodated in the optical fiber ribbon accommodating section S1 in Fig. 1A is the glass fiber 211a of the optical fiber core 211, and the optical fiber ribbon accommodating section S1 is the space inside the jacket 3 excluding the thicknesses of the first pressing member 6 and the second pressing member 7.

[0039] When the optical fiber cable 1 of FIG. 1A is manufactured with the inner diameter ID of the outer jacket 3 set to 24.8 mm, the thickness t1 of the first pressing member 6 set to 0.3 mm, the thickness t2 of the second pressing member 7 set to 0.35 mm, and the diameter R1 of the glass fiber 211a of the optical fiber core 211 set to 0.125 mm, the cross-sectional area of ​​the optical fiber ribbon accommodating section S1 is calculated by subtracting the thickness t1 of the first pressing member 6 and the thickness t2 of the second pressing member 7 from the inner diameter ID of the outer jacket 3 and assuming the effective inner diameter to be 23.5 mm, as follows: π×(23.5 / 2) 2 =434 mm 2 The cross-sectional area of ​​the glass contained in the optical fiber ribbon containing section S1 is π×(0.125 / 2) 2 ×6912=84.8mm 2 Therefore, the ratio of the cross-sectional area of ​​the glass accommodated in the optical fiber ribbon accommodating portion S1 to the cross-sectional area of ​​the optical fiber ribbon accommodating portion S1 is about 20%.

[0040] As described above, in the optical fiber cable 1 according to the present embodiment, the ratio of the inner diameter ID to the outer diameter OD of the jacket 3 is 0.75 or more, so that a larger number of optical fiber cores 211 can be arranged inside the jacket 3. On the other hand, the larger the ratio of the inner diameter ID to the outer diameter OD of the jacket 3, the more likely the optical fiber cable 1 is to deform when lateral pressure is applied to the optical fiber cable 1. However, since the number of optical fiber cores 211 mounted in the optical fiber cable 1 is 3000 or more, the optical fiber cores mounted at high density in the optical fiber cable can suppress crushing and kinking of the optical fiber cable 1. In addition, since the ratio of the cross-sectional area of ​​the glass accommodated in the optical fiber ribbon housing section S1 to the cross-sectional area of ​​the optical fiber ribbon housing section S1 is 15% or more and 25% or less, the optical fiber cable can withstand the tension applied thereto. Therefore, an optical fiber cable capable of mounting optical fiber cores at high density and having lateral pressure resistance can be provided.

[0041] In the present embodiment, the optical fiber cable 1 includes a plurality of optical fiber units 2 formed by bundling a plurality of optical fiber ribbons 21. This makes it easy to distinguish and handle the optical fiber ribbons 21 in the optical fiber cable 1.

[0042] In the present embodiment, the optical fiber cable 1 has a first pressing member 6 and a second pressing member 7. This makes it possible to easily distinguish between the optical fiber units 2 located inside the first pressing member 6 and the optical fiber units 2 located outside the first pressing member 6, even in the case of a multi-core cable having 3000 or more cores.

[0043] The first pressing member 6 may be formed of a material that provides a low friction surface facing the second pressing member 7. The first pressing member 6 is formed, for example, so that the dynamic friction coefficient between the first pressing member 6 and the optical fiber ribbon 21 that constitutes the optical fiber unit 2 arranged on the outside of the first pressing member 6 is 0.3 or less. The second pressing member 7 may be formed of a material that provides a low friction surface facing the first pressing member 6. The second pressing member 7 is formed, for example, so that the dynamic friction coefficient between the second pressing member 7 and the optical fiber ribbon 21 that constitutes the optical fiber unit 2 arranged on the inside of the first pressing member 6 is 0.3 or less. The optical fiber unit 2 mounted in the optical fiber cable 1 is likely to move in the longitudinal direction due to temperature contraction in a low temperature environment. Therefore, an increase in transmission loss in a low temperature environment can be suppressed. The dynamic friction coefficient can be measured in accordance with ISO standard 8295, for example, between each sheet-like pressing member and the optical fiber ribbon.

[0044] In addition, in this embodiment, the optical fiber cable 1 may be configured so that the ratio of the cross-sectional area of ​​the optical fiber ribbon 21 accommodated in the optical fiber ribbon accommodating section S1 to the cross-sectional area of ​​the optical fiber ribbon accommodating section S1 inside the outer jacket 3 is 50% or more and 65% or less.

[0045] In the optical fiber cable 1 of FIG. 1A, when the optical fiber ribbon 21 is manufactured with the diameter R2 of the optical fiber core 211 of 200 μm and the diameter T of the optical fiber core 211 including the ribbon resin 212 of the optical fiber ribbon 21 of 225 μm, the cross-sectional area of ​​the optical fiber ribbon 21 is π×(0.225 / 2) 2 ×6912=275mm 2 Therefore, the ratio of the cross-sectional area of ​​the optical fiber ribbon 21 accommodated in the optical fiber ribbon accommodating portion S1 to the cross-sectional area of ​​the optical fiber ribbon accommodating portion S1 is approximately 63%.

[0046] According to this configuration, the ratio of the cross-sectional area of ​​the optical fiber ribbon 21 accommodated in the optical fiber ribbon accommodating section S1 to the cross-sectional area of ​​the optical fiber ribbon accommodating section S1 is 50% or more, so that even if lateral pressure is applied to the optical fiber cable 1, the optical fiber cable 1 can be prevented from being crushed because the optical fiber core wires 211 constituting the optical fiber ribbon 21 are accommodated at a high density. On the other hand, when the ratio of the cross-sectional area of ​​the optical fiber ribbon 21 accommodated in the optical fiber ribbon accommodating section S1 to the cross-sectional area of ​​the optical fiber ribbon accommodating section S1 becomes high, the transmission loss increases. However, since the ratio of the cross-sectional area of ​​the optical fiber ribbon 21 accommodated in the optical fiber ribbon accommodating section S1 to the cross-sectional area of ​​the optical fiber ribbon accommodating section S1 is 65% or less, the increase in transmission loss can be suppressed.

[0047] In this embodiment, the optical fiber unit 2 may have a tube 22 that covers the periphery of the assembly of optical fiber ribbons 21, as exemplified in FIG. 4. The tube 22 has a thickness of, for example, 0.01 mm or more and 0.2 mm or less. According to such a configuration, for example, by making the colors of the tubes 22 different, it becomes easy to distinguish the optical fiber units 2 in the optical fiber cable 1. In addition, when storing the optical fiber units 2 of the optical fiber cable 1 in an optical connection box, a closure, or the like, it is not necessary to cover the optical fiber ribbons 21 exposed after removing the jacket 3 with a protective tube, so that the workability is improved. In addition, since the thickness of the tube 22 is thin, it is possible to suppress a reduction in the space in which the optical fiber ribbons 21 can be mounted due to the placement of the tube 22. In this example, all the optical fiber units 2 are covered with the tube 22, but, for example, only a part of the optical fiber units 2 may be covered with the tube 22. By reducing the number of the tubes 22, more optical fiber cores 211 can be mounted in the optical fiber cable 1.

[0048] Second Embodiment The configuration of the optical fiber cable 10 according to the second embodiment will be described with reference to Figures 5A and 5B. In Figure 5A, the optical fiber unit 12 is hatched to omit its internal configuration, and the omitted internal structure of the optical fiber unit 12 is illustrated in Figure 5B. The circular frame shown by the dashed line in Figures 5A and 5B shows the area of ​​the optical fiber unit 12 for the sake of convenience, and in reality, no frame exists.

[0049] 5A, the optical fiber cable 10 includes a tension member 11, a plurality of optical fiber units 12, and an outer jacket 13. In this example, 64 optical fiber units 12 are mounted inside the outer jacket 13.

[0050] The tension member 11 is disposed at the center of the optical fiber cable 10 along the central axis of the optical fiber cable 10. The tension member 11 has, for example, a glass fiber reinforced plastic (GFRP) 11A and a coating 11B that covers the periphery of the GFRP 11A. Note that, although one tension member 11 is disposed within the optical fiber cable 10 in this example, a plurality of tension members 11 may be disposed together.

[0051] The optical fiber units 12 are wound around the tension member 11 in a multi-layer structure with the tension member 11 at the center. The optical fiber unit 12 has a plurality of optical fiber ribbons 121, as illustrated in Fig. 5B. In this example, the optical fiber unit 12 is formed by an assembly of 18 optical fiber ribbons 121 bundled together. The 18 optical fiber ribbons 121 forming the assembly may be twisted together.

[0052] 2 and 3, the optical fiber ribbons 121 are provided with connection portions 213 in which adjacent optical fiber cores 211 are connected between some or all of the optical fiber cores 211, and non-connection portions 214 in which adjacent optical fiber cores 211 are not connected, which are intermittently provided in the longitudinal direction of the optical fiber cores 211. The configuration of the optical fiber ribbon 121 is the same as that of the optical fiber ribbon 21 of the first embodiment, and therefore a detailed description thereof will be omitted.

[0053] The jacket 13 is formed so as to cover the periphery of the plurality of optical fiber units 12. The jacket 13 is formed, for example, from a resin having a Young's modulus of 1500 MPa or more at room temperature (for example, 23° C.). A tear string 14 may be embedded in the jacket 13.

[0054] The optical fiber cable 10 may further have a pressing member that covers the periphery of the optical fiber units 12. In this example, the optical fiber cable 10 has a first pressing member 15 and a second pressing member 16. The first pressing member 15 and the second pressing member 16 are made of, for example, polyester nonwoven fabric. The first pressing member 15 is placed vertically or wound spirally around the multiple optical fiber units 12 arranged at the center of the cable. The second pressing member 16 is placed vertically or wound spirally around the multiple optical fiber units 12 arranged around the first pressing member 15.

[0055] In the optical fiber cable 10 thus configured, the jacket 13 is formed so that the ratio of the outer diameter OD to the inner diameter ID (ID / OD) is 0.75 or more. For example, when the optical fiber cable 10 in Fig. 5A is manufactured with the outer diameter OD of the jacket 13 being 40.4 mm and the inner diameter ID of the jacket 13 being 34.8 mm, the ratio of the inner diameter ID to the outer diameter OD is approximately 0.86.

[0056] Moreover, 3000 or more optical fiber cores 211 are mounted in the optical fiber cable 10. For example, 13824 optical fiber cores 211 are mounted in the optical fiber cable 10 of FIG.

[0057] The optical fiber cable 10 is configured so that the ratio of the cross-sectional area of ​​the glass accommodated in the optical fiber ribbon accommodating section S11 to the cross-sectional area of ​​the optical fiber ribbon accommodating section S11 is 15% or more and 25% or less. In this example, the glass mounted in the optical fiber cable 10 of Fig. 5A includes the GFRP 11A constituting the tension member 11 in addition to the glass fiber 211a of the optical fiber core 211. When the optical fiber cable 10 of Fig. 5A is manufactured with the inner diameter ID of the jacket 13 being 34.8 mm, the thickness of the first pressing member 15 being 0.3 mm, the thickness of the second pressing member 16 being 0.35 mm, the diameter R1 of the glass fiber 211a of the optical fiber core 211 being 0.125 mm, and the diameter of the GFRP 11A being 4 mm, the cross-sectional area of ​​the optical fiber ribbon accommodating section S11 is calculated as π × (33.5 / 2) by subtracting the thickness of the first pressing member 15 and the thickness of the second pressing member 16 from the inner diameter ID of the jacket 3 and assuming the effective inner diameter to be 33.5 mm, as described above. 2 =881mm 2 The cross-sectional area of ​​the glass accommodated in the optical fiber ribbon accommodation section S11 is π×(0.125 / 2) 2 ×13824+π×(4 / 2) 2 =182mm 2 Therefore, the ratio of the cross-sectional area of ​​the glass accommodated in the optical fiber ribbon accommodating portion S11 to the cross-sectional area of ​​the optical fiber ribbon accommodating portion S11 is about 21%.

[0058] The optical fiber cable 10 can be configured so that the ratio of the cross-sectional area of ​​the optical fiber ribbon 121 accommodated in the optical fiber ribbon accommodation section S11 to the cross-sectional area of ​​the optical fiber ribbon accommodation section S11 is 50% or more and 65% or less. In the optical fiber cable 10 of Fig. 5A, when the optical fiber ribbon 121 is manufactured with the diameter R2 of the optical fiber core 211 of 200 µm and the diameter T of the optical fiber core 211 including the ribbon resin 212 of the optical fiber ribbon 121 of 225 µm, the cross-sectional area of ​​the optical fiber ribbon 121 is π × (0.225 / 2) 2 ×13824=549.6550mm 2Therefore, the ratio of the cross-sectional area of ​​the optical fiber ribbon 121 accommodated in the optical fiber ribbon housing portion S11 to the cross-sectional area of ​​the optical fiber ribbon housing portion S11 is approximately 62%.

[0059] As described above, the optical fiber cable 10 according to this embodiment can have the same effects as the optical fiber cable 1 according to the first embodiment. In addition, since the glass fiber 211a of the optical fiber core 211 itself functions as a tension member, even if the size of the tension member 11 arranged in the optical fiber cable 10 is reduced, it can withstand the tension applied to the optical fiber cable. This allows a larger number of optical fiber cores 211 to be mounted.

[0060] In this embodiment, the multiple optical fiber units 12 are wound around the tension member 11 in a multi-layer structure with the tension member 11 at the center. As a result, the tension member 11 is disposed at the center of the multiple optical fiber cables, so the optical fiber cable 10 is not easily bent in only a specific direction, but can be bent in all directions with the same force.

[0061] In this embodiment, the optical fiber unit 12 may have a tube 22 that covers the periphery of the assembly of optical fiber ribbons 121, as exemplified in FIG.

[0062] Although the present disclosure has been described in detail and with reference to specific embodiments, it is clear to those skilled in the art that various changes and modifications can be made without departing from the spirit and scope of the present disclosure. Furthermore, the number, position, shape, etc. of the components described above are not limited to the above embodiments, and can be changed to the number, position, shape, etc. that are suitable for implementing the present disclosure.

[0063] The optical fiber cable 1 of the first embodiment may be formed as a connectorized cable 30, as exemplified in FIG. 6. That is, the connectorized cable 30 includes an optical fiber cable 1 and a multi-core connector 31 provided at one end of at least one optical fiber unit 2 of the optical fiber cable 1. In FIG. 6, the multi-core connector 31 is connected to the optical fiber unit 2. By connecting the optical fiber unit 2 to the multi-core connector 31 in advance, the workability when optically connecting the optical fiber cable 1 can be made easier. A plurality of multi-core connectors may be connected to each optical fiber unit 2. Similarly, the optical fiber cable 10 of the second embodiment may be formed as a connectorized cable 30, as exemplified in FIG. 6.

[0064] In the above first embodiment, the optical fiber unit 2 may have a bundle material wound around an assembly of a plurality of optical fiber ribbons 21, instead of the tube 22. Even in this case, by making the colors of the bundle materials different, it becomes easy to distinguish the optical fiber units 2 within the optical fiber cable 1. Similarly, in the second embodiment, the optical fiber unit 12 may have a bundle material wound around an assembly of a plurality of optical fiber ribbons 121, instead of the tube 22.

[0065] In the above first embodiment, the multiple optical fiber ribbons 21 forming the assembly are twisted together, but the multiple optical fiber ribbons 21 may form the assembly without being twisted together. Similarly, in the second embodiment, the multiple optical fiber ribbons 121 forming the assembly are twisted together, but the multiple optical fiber ribbons 121 may form the assembly without being twisted together.

[0066] In the first embodiment, the first pressing member 6 and the second pressing member 7 may have water absorption properties. Similarly, in the second embodiment, the first pressing member 15 and the second pressing member 16 may have water absorption properties. The first pressing members 6, 15 and the second pressing members 7, 16 may be formed, for example, by adhering water-absorbent powder to a base fabric made of polyester or the like. This makes it possible to prevent water from penetrating into the first pressing members 6, 15 and the second pressing members 7, 16.

[0067] In the above first and second embodiments, the optical fiber ribbon 21 and the optical fiber ribbon 121 are arranged in parallel with 12 optical fiber cores 211 in contact with each other, but the number of optical fiber cores 211 and the contact state between adjacent optical fiber cores 211 are not limited to the structures in Figures 2 and 3 and can be changed as appropriate.

[0068] In the above first embodiment, the multiple optical fiber units 2 may be twisted together along the longitudinal direction of the optical fiber cable 1. Similarly, in the second embodiment, the multiple optical fiber units 12 may be twisted together along the longitudinal direction of the optical fiber cable 10. [Explanation of symbols]

[0069] 1: Fiber optic cable 2: Optical fiber unit 3:Outer cover 4: Tear string 5: Tension member 6: First holding member 7: Second holding member 10: Fiber optic cable 11: Tension member 11A:GFRP 11B: Covering part 12: Optical fiber unit 13:Outer cover 14: Tear string 15: First holding member 16: Second holding member 21: Optical fiber ribbon 22: Tube 30: Cable 31: Multi-core connector 121: Optical fiber ribbon 211: Optical fiber core 211a: Glass fiber 211b: Covering part 212: Ribbon resin 213:Connection part 214: Unconnected part ID: Inner diameter OD: Outer diameter R1: diameter of glass fiber R2: Diameter of optical fiber core S1: Optical fiber ribbon storage section S11: Optical fiber ribbon storage section T: Diameter of optical fiber core including ribbon resin

Claims

1. A plurality of optical fiber ribbons; a jacket covering the periphery of the plurality of optical fiber ribbons; Equipped with The optical fiber ribbon has a plurality of optical fiber core wires, and the plurality of optical fiber core wires are arranged in parallel in a direction perpendicular to the longitudinal direction, and among some or all of the optical fiber core wires, connected portions in which adjacent optical fiber core wires are connected and non-connected portions in which adjacent optical fiber core wires are not connected are intermittently provided in the longitudinal direction of the optical fiber core wires, The optical fiber core includes a glass fiber and a coating portion that covers the glass fiber, The ratio of the inner diameter to the outer diameter of the jacket is 0.75 or more, a ratio of an area of ​​the glass accommodated in the optical fiber ribbon accommodating portion to an area of ​​the optical fiber ribbon accommodating portion inside the jacket in a cross section perpendicular to the longitudinal direction of the optical fiber cable is 15% or more and 25% or less; The number of the optical fiber cores mounted in the optical fiber cable is 3000 or more, and the outer diameter of the jacket is 50 mm or less, An optical fiber cable, wherein the ratio of the area of ​​the optical fiber ribbon in the cross section accommodated in the optical fiber ribbon accommodating portion to the area of ​​the optical fiber ribbon accommodating portion inside the outer jacket in the cross section is 50% or more and 65% or less.

2. a first pressing member for covering a circumference of a part of the plurality of optical fiber ribbons; 2. The optical fiber cable according to claim 1, further comprising: a second pressing member that covers the remaining optical fiber ribbons of the plurality of optical fiber ribbons arranged outside the first pressing member.

3. The optical fiber cable of claim 2, wherein a dynamic friction coefficient between the first holding member and the optical fiber ribbon arranged outside the first holding member is 0.3 or less, and a dynamic friction coefficient between the second holding member and the optical fiber ribbon arranged inside the second holding member is 0.3 or less.

4. The optical fiber cable according to claim 1 , comprising a plurality of assemblies in which at least a portion of the plurality of optical fiber ribbons are bundled together.

5. The device includes a plurality of tubes having a thickness of 0.01 mm or more and 0.2 mm or less, The optical fiber cable according to claim 4 , wherein the tube is formed so as to surround the assembly.

6. At least one tension member is provided, 6. The optical fiber cable according to claim 1, wherein the plurality of optical fiber ribbons are wound around the tension member in a multi-layer structure with the tension member as a center.

7. The optical fiber cable according to any one of claims 1 to 6, a multi-fiber connector provided at one end of at least one of the optical fiber ribbons of the optical fiber cable.

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