JP2011232373A - Coated optical fiber ribbon, optical fiber cable, and method for splicing optical fiber - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a coated optical fiber ribbon reducing orientation in flexural rigidity and having workability for storing an excess length of fibers, and to provide an optical fiber cable and a method for splicing optical fibers.SOLUTION: A coated optical fiber ribbon 10 has an arrangement of fibers in such a manner that a center A2 of a second coated optical fiber 18 and a center A3 of a third coated optical fiber 19 are deviated from a center axial line A0 connecting a center A1 of a first coated optical fiber 17 at one end and a center A4 of a fourth coated optical fiber 20 at the other. By disposing the second coated optical fiber 18 and the third coated optical fiber 19, excluding the first coated optical fiber 17 and the fourth coated optical fiber 20 at both ends, being deviated from the center axis line A0, the ribbon width L1 can be reduced.

Description

  TECHNICAL FIELD The present invention relates to an optical fiber ribbon in which a plurality of single-core optical fibers are assembled, a method for connecting the optical fibers, and a multi-fiber optical fiber cable in which a large number of optical fiber ribbons are further assembled.

As an example of a conventional multi-core optical fiber cable, a multi-core optical fiber cable 200 shown in FIG. 9 is formed by straightening or twisting four single-core coated optical fibers 201 and winding them together with an identification yarn 202. Later, it is assembled in the spacer groove 205 of the spacer 203 having the tension member 204 in the center, and the pressing tape 206 is wound around the outer periphery thereof, and the outer cover 207 is formed on the outer periphery thereof (see, for example, Patent Document 1).
Further, the multi-core optical fiber cable 210 shown in FIG. 10 is obtained by aligning and laminating a plurality of optical fiber ribbons 212 made of four optical fibers 211 in a spacer groove 205.

JP-A-11-6943

However, the conventional multi-core optical fiber cable 200 disclosed in Patent Document 1 cannot perform connection work at the cable terminal in a lump. For example, in the case of a 1000-core cable, it is necessary to perform 1000 fusion connections. There was a long time for connection work.
In addition, if the optical fiber ribbon 212 of the multi-core optical fiber cable 210 is used, a plurality of optical fibers can be connected together. However, when storing the tape core with a width in the extra storage section such as a closure, it is necessary to store it after aligning the bending direction properly due to the direction of the bending rigidity. There was a problem that it took.

  The object of the present invention is to solve the above-mentioned problems. The merit of the tape core wire that can be connected in a lump and the direction of the bending rigidity is reduced by narrowing the tape width as much as possible, and the extra length is stored. An object of the present invention is to provide an optical fiber ribbon, an optical fiber cable, and an optical fiber connection method having workability.

  An optical fiber ribbon according to the present invention that can solve the above-mentioned problems is an optical fiber ribbon that covers the entire circumference of three or more optical fibers, and the optical fiber ribbons at both ends are provided. It is characterized in that the other optical fiber cores are arranged so that there is no center on the central axis connecting the centers.

  According to the thus configured optical fiber ribbon, the centers of the other optical fibers are arranged at positions shifted from the central axis connecting the optical fibers at both ends. As a result, the tape width of the tape core can be reduced, so that it is possible to combine the merit of the tape core that can be connected at once and the advantage of easy storage of the extra length by reducing the direction of bending rigidity. . According to the substantially tape-shaped core wire form, it becomes the same shape as a conventional tape core wire arranged in parallel by pressing, so that it can be connected in the same short time as a conventional tape core wire.

  Further, in the optical fiber ribbon according to the present invention, it is thinner than the outer diameter of the optical fiber including the jacket covering the outer periphery of the optical fiber between at least a pair of the optical fibers. It is preferable that a bridge portion is provided to integrate a plurality of the optical fiber core wires.

  According to the thus configured optical fiber tape core wire, since it is integrated by at least the bridge portion between the pair of optical fiber core wires, the connecting portion which is the bridge portion by pressing from the thickness direction of the tape core wire Can be easily divided. As a result, it is possible to perform the fusion splicing after setting the tape core wire in the optical fiber holder of the fusion splicer and aligning the centers of the plurality of optical fiber core wires in parallel in one plane. . Moreover, the relative position of the adjacent optical fiber cores becomes movable by the bridge portion, and the optical fiber core wires can be shifted in a direction to reduce distortion when the optical fiber cable is housed in the optical fiber cable.

  In the optical fiber ribbon according to the present invention, it is preferable that a plurality of the optical fiber cores other than the optical fiber cores at both ends are alternately shifted with respect to the central axis.

  According to the optical fiber ribbon configured as described above, the optical fiber cores other than the optical fiber cores at both ends are alternately displaced with respect to the central axis, so that there is no gap between the optical fiber cores. Compared with a conventional completely parallel tape core wire that can be narrowed and cannot be bent in the width direction, the directionality of the bending rigidity can be reduced. As a result, when storing the optical fiber core in the extra length storage case inside the closure, it is not necessary to carefully align the optical fiber core in consideration of the direction of bending of the optical fiber core, thereby shortening the storage operation. be able to.

  In the optical fiber ribbon according to the present invention, it is preferable that the center positions of the adjacent optical fibers are sequentially shifted in the width direction of the tape strand.

  According to the thus configured optical fiber ribbon, when pressing from the thickness direction of the optical fiber ribbon to collapse it into a flat tape shape, the center position of the adjacent optical fibers is the tape core. Since they are sequentially shifted in the width direction, it is possible to reliably avoid changing the arrangement order of the optical fiber core wires in the optical fiber holder of the fusion splicer.

  An optical fiber cable according to the present invention capable of solving the above-mentioned problems is obtained by assembling a plurality of the optical fiber ribbons in a spacer, winding a presser winding around the outer periphery thereof, and applying a jacket with a thermoplastic resin. It is characterized by.

  According to the optical fiber cable configured as described above, it is possible to manufacture a cable that maintains the same stable distortion / transmission loss as a cable using a conventional parallel optical fiber ribbon. Also, a fusion splicing connection can be performed at the time of optical fiber connection.

  An optical fiber connecting method according to the present invention that can solve the above-mentioned problems is characterized in that the connection end of the optical fiber ribbon is disposed on the optical fiber alignment groove of the optical fiber holder of the fusion splicer. The centers of the plurality of optical fiber cores are aligned in parallel in one plane by being pressed with an upper pressing lid, and then collectively fused and connected.

  According to the optical fiber connecting method configured as described above, the connection end portion of the optical fiber ribbon in which a plurality of optical fibers are gathered is disposed on the optical fiber alignment groove of the optical fiber holder and pressed by the upper pressing lid. As a result, the centers of the plurality of optical fiber core wires can be aligned in parallel in one plane, so that the connection work is facilitated and the work time can be shortened. In the case of a single-core optical fiber, the work of setting a plurality of optical fibers in parallel in an optical fiber holder is complicated and takes time.

  According to the optical fiber ribbon, the optical fiber cable, and the optical fiber connection method according to the present invention, the advantages of the tape core that can be connected at once, and the advantage that the extra length can be easily stored by reducing the direction of bending rigidity. Can be combined.

It is sectional drawing of the optical fiber ribbon based on 1st Embodiment of this invention. It is the schematic which shows the optical fiber connection method to which the optical fiber tape core wire of FIG. 1 is applied, (A) is sectional drawing of a 1st step, (B) is sectional drawing of a 2nd step. It is sectional drawing of the optical fiber cable to which the optical fiber tape core wire of FIG. 1 is applied. It is sectional drawing of the optical fiber tape cable core which concerns on 2nd Embodiment of this invention. It is sectional drawing of the optical fiber ribbon based on 3rd Embodiment of this invention. It is sectional drawing of the optical fiber tape cable core which concerns on 4th Embodiment of this invention. It is sectional drawing of the optical fiber ribbon based on 5th Embodiment of this invention. It is sectional drawing of the optical fiber ribbon based on 6th Embodiment of this invention. It is sectional drawing of the conventional optical fiber cable. It is sectional drawing of another conventional optical fiber cable.

  Hereinafter, optical fiber ribbons according to a plurality of embodiments of the present invention will be described with reference to the drawings.

(First embodiment)
As shown in FIG. 1, the optical fiber ribbon 10 according to the first embodiment of the present invention includes a first optical fiber 17, a second optical fiber 18, a third optical fiber 19, and a fourth optical fiber. This is a deformation type tape core consisting of four cores of the optical fiber core 20. Each optical fiber core wire 17-20 has the glass fiber 11-14 which consists of a core and a clad in the center, and has the structure which coat | covered the outer periphery of this glass fiber 14 with the protective coating 15 made from resin. Each of the optical fiber cores 17 to 20 is covered with an outer cover 16, and adjacent optical fiber cores are connected in parallel by a bridge portion 21.

  The optical fiber ribbon 10 has a central axis A0 connecting the center A1 of the first optical fiber 17 and the center A4 of the fourth optical fiber 20 at both ends on the other second optical fibers 18. The optical fiber core wires 17 to 20 are arranged in a staggered manner so that the center A2 and the center A3 of the third optical fiber core wire 19 do not exist.

  The optical fiber ribbon 10 has, for example, a width dimension L1 of 0.80 mm, a height dimension L2 of 0.53 mm, and a thickness dimension T1 of the jacket 16 of 0.015 mm. Therefore, the outer diameter dimension H1 including the outer jacket 16 on the outer periphery of each of the first optical fiber core wires 17 to 20 is, for example, 0.28 mm.

  In the optical fiber ribbon 10, a predetermined interval L <b> 4 is provided between the first optical fiber 17 and the second optical fiber 18. The predetermined distance L4 is formed by connecting the first optical fiber core wire 17 and the second optical fiber core wire 18 with a bridge portion 21 integral with the jacket 16. The bridge portion 21 is arranged on the central axis A5 that connects the center A1 of the first optical fiber core 17 and the center A2 of the second optical fiber core 18 with the outer cover 16 and the second light on the first optical fiber core 17 side. The jacket 16 on the side of the fiber core 18 is connected.

Similarly, the distance between the second optical fiber core 18 and the third optical fiber core 19 and the distance between the third optical fiber core 19 and the fourth optical fiber core 20 are also set on the central axes A6 and A7 by the bridge portion 21. The predetermined interval L4 is formed by connecting with each other. As for the dimensions of the bridge portion 21, for example, the thickness dimension L3 is 60 μm thinner than the above-described outer diameter dimension H1, and the length dimension L4 is 50 μm.
A colored layer having a thickness of about 1 μm to 10 μm may be formed on the outer periphery of the protective coating 15. Moreover, the thin film-like carbon layer may be coated around each glass fiber 11-14.

  As a material for the jacket 16 and the bridge portion 21, a UV acrylate resin can be used. The Young's modulus of the UV acrylate resin is preferably in the range of 0.5 to 45 MPa, and the elongation is preferably in the range of 75 to 250%. Thereby, the flexibility of the bridge part 21 is securable. Further, by using a UV acrylate resin having a large elongation, it is possible to prevent breakage when the bridge portion 21 is bent.

Next, an optical fiber connection method to which the optical fiber ribbon 10 is applied will be described.
As shown in FIG. 2A, a fusion splicer is used to connect the optical fiber ribbon 10. The optical fiber holder 30 set in the fusion splicer includes an optical fiber alignment groove 32 on the upper surface of the base 31, and a hinge 33 is provided at the end of the base 31 so as to close the optical fiber alignment groove 32. The upper presser lid 34 connected is provided.

  In the first stage of the optical fiber connection process, the optical fiber ribbon 10 is disposed in the optical fiber alignment groove 32 of the optical fiber holder 30. At this time, since the optical fiber ribbon 10 has a height dimension sufficiently larger than the optical fiber alignment groove 32, it protrudes from the optical fiber alignment groove 32.

  In the second stage of the optical fiber connection process, the optical fiber alignment groove 32 is closed while pressing the upper portion of the protruding optical fiber ribbon 10 by rotating the upper pressing lid 34 in the closing direction. Thereby, the height dimension L2 of the optical fiber ribbon 10 is crushed and deformed in parallel in one plane. That is, the bridge portion 21 is broken by the pressing force of the upper pressing lid 34, and the height dimension L2 is changed to the outer diameter dimension H1 described above. The bridge portion 21 may be deformed or cut when crushed.

  Next, the protective coating 15 and the jacket 16 of the optical fiber ribbon 10 protruding from the distal end side of the optical fiber holder 30 are removed from a predetermined location using a coating remover, and the glass fibers 11 to 11 on the distal end side are removed. 14 is exposed. Thereafter, the exposed glass fibers 11 to 14 are cut into a predetermined length to align the connection ends. These coating removal and fiber cutting can be performed efficiently because the optical fiber ribbon 10 is aligned and held at a predetermined pitch at the holder tip.

  Next, the fusion bonding connection is performed in a state in which the optical fiber ribbon 10 is held in contact with the connection end of a not-shown counterpart optical fiber ribbon.

  As shown in FIG. 3, a plurality of the optical fiber ribbons 10, for example, two optical fiber ribbons 10 are assembled in the spacer groove 4 of the spacer 2 having the tension member 3 around the optical fiber ribbon 10. A presser winding 5 is wound on the outer periphery. Further, an outer fiber 6 made of a thermoplastic resin is applied to the outer periphery to form the optical fiber cable 1.

As described above, according to the optical fiber ribbon 10 of the first embodiment, from the center axis A0 connecting the center A1 of the first optical fiber 17 and the center A4 of the fourth optical fiber 20 at both ends. The center A2 of the second optical fiber core 18 and the center A3 of the third optical fiber core 19 are disposed at the shifted positions. Accordingly, the second optical fiber core wire 18 and the third optical fiber core wire 19 other than the first optical fiber core wire 17 and the fourth optical fiber core wire 20 at both ends are arranged so as to be shifted from the central axis A0. The width L1 can be reduced.
Therefore, the optical fiber ribbon 10 has both the merit of the tape core that can be connected in a lump and the merit of reducing the direction of the bending rigidity to facilitate the storing operation. Because of the substantially tape-shaped core wire form, it becomes the same shape as the conventional tape core wires arranged in parallel by pressing, so that it can be connected in the same short time as a conventional tape core wire.

Further, between the first optical fiber core wire 17 and the second optical fiber core wire 18, between the second optical fiber core wire 18 and the third optical fiber core wire 19, and between the third optical fiber core wire 19 and the first optical fiber core wire 19. A bridge portion 21 that is thinner than the outer diameter dimension H1 of the optical fiber core wires 17 to 20 including the outer sheath 16 that covers the outer periphery of the optical fiber core wires 17 to 20 is provided between the four optical fiber core wires 20 and a plurality of bridge portions 21. The optical fiber core wires 17 to 20 were integrated. Thereby, the tape core wire 10 can be set in the optical fiber holder 30, and the connection part which is the bridge part 21 can be easily parted by the press from the thickness direction of the tape core wire 10. FIG.
Therefore, after the centers of the plurality of optical fiber core wires 17 to 20 are aligned in parallel in one plane, the fusion splicing can be performed. Moreover, the relative position of the adjacent optical fiber cores becomes movable by the bridge portion 21 and the optical fiber core wires 17 to 20 can be shifted in a direction to reduce the distortion when the optical fiber cable 1 is housed in the optical fiber cable 1.

  Further, the plurality of optical fiber core wires 18 and 19 other than the optical fiber core wires 17 and 20 at both ends are alternately displaced with respect to the central axis A0. Thereby, between each optical fiber core wire 17-20 can be narrowed, compared with the conventional completely parallel tape core wire, each optical fiber core wire 17-20 can be concentrated, and directionality of bending rigidity Can be reduced. When the multi-core optical fiber cable 1 is formed with the optical fiber ribbon 10, the optical fibers 17 to 20 can move with the flexible bridge portion 21 as a fulcrum. As a result, the multi-core optical fiber cable 1 that maintains stable transmission performance with low distortion can be realized.

  Further, the centers A1 to A4 of the adjacent optical fiber cores 17 to 20 are shifted from each other in the width direction of the tape core wire 10. Thereby, when pressing is applied from the thickness direction of the tape core wire 10 in the optical fiber holder 30, it is possible to reliably avoid changing the arrangement order of the optical fiber core wires 17 to 20.

  Further, according to the optical fiber cable 1 of the first embodiment, a plurality of the optical fiber ribbons 10 are assembled in the spacer groove 4, the presser winding 5 is wound around the outer periphery, and the jacket 6 is applied with a thermoplastic resin. ing. Thereby, the stable distortion / transmission loss equivalent to the conventional spacer type cable can be maintained. Also, a fusion splicing connection can be performed at the time of optical fiber connection.

  Furthermore, according to the optical fiber connection method of the first embodiment, the connection end of the optical fiber ribbon 10 is disposed on the optical fiber alignment groove 32 of the optical fiber holder 30, and the upper presser lid of the optical fiber holder 30. Press at 34. As a result, the centers A1 to A4 of the plurality of optical fiber cores 17 to 20 are aligned in parallel in one plane and then collectively fused and connected. Therefore, connection work becomes easy and work time can be shortened.

(Second Embodiment)
Next, the optical fiber ribbon according to the second embodiment of the present invention will be described. In the following embodiments, the same components as those in the first embodiment described above are denoted by the same or similar reference numerals, and the description of the configuration and operational effects is omitted.

  As shown in FIG. 4, the optical fiber ribbon 40 according to the second embodiment of the present invention includes a first optical fiber 51, a second optical fiber 52, a third optical fiber 53, and a fourth optical fiber. This is a deformed type tape core consisting of eight cores of an optical fiber core 54, a fifth optical fiber core 55, a sixth optical fiber core 56, a seventh optical fiber core 57, and an eighth optical fiber core 58.

  The optical fiber ribbon 40 has a center B2 of the second optical fiber 52 with respect to a central axis B0 connecting the center B1 of the first optical fiber 51 and the center B8 of the eighth optical fiber 58 at both ends. The center B3 of the third optical fiber core 53, the center B4 of the fourth optical fiber core 54, the center B5 of the fifth optical fiber core 55, the center B6 of the sixth optical fiber core 56, and the seventh optical fiber core The centers B7 of the lines 57 are alternately shifted and arranged in a zigzag shape.

  Each of the optical fiber cores 51 to 58 has glass fibers 41 to 48 including a core and a clad at the center, and the outer periphery of the glass fibers 41 to 48 is covered with a resin protective coating 49. Each of the optical fiber cores 51 to 58 is covered with an outer jacket 50, and adjacent optical fiber core wires are connected in parallel by a bridge portion 59.

  In the optical fiber ribbon 40, the first optical fiber core 51 and the second optical fiber core 52 are integrated at a predetermined interval by a bridge portion 59 provided on the central axis B9. Similarly, between the second optical fiber core wire 52 and the third optical fiber core wire 53, between the third optical fiber core wire 53 and the fourth optical fiber core wire 54, and between the fourth optical fiber core wire 54 and the fifth light. A predetermined interval is formed between the fiber cores 55 by a bridge portion 59 provided on the central axes B10 to B12. Further, between the fifth optical fiber core 55 and the sixth optical fiber core 56, between the sixth optical fiber core 56 and the seventh optical fiber core 57, and between the seventh optical fiber core 57 and the eighth optical fiber. A predetermined interval is formed between the core wires 58 by a bridge portion 59 provided on the central axes B13 to B15.

  As described above, according to the optical fiber ribbon 40 of the second embodiment, each of the optical fiber cores 52 to 57 other than the first optical fiber core 51 and the eighth optical fiber core 58 at both ends is center axis B0. Are alternately arranged. As a result, the direction of the bending rigidity of the optical fiber ribbon 40 can be reduced, and it is not necessary to carefully align the ribbons during the extra length storage operation, thereby shortening the extra length storage operation time. it can.

(Third embodiment)
Next, an optical fiber ribbon according to a third embodiment of the present invention will be described.
As shown in FIG. 5, the optical fiber ribbon 60 according to the third embodiment of the present invention includes a first optical fiber 67, a second optical fiber 68, a third optical fiber 69, and a fourth optical fiber. This is a deformed type tape core consisting of four cores of the optical fiber core 70.

  The optical fiber ribbon 60 has a center C2 of the second optical fiber 68 with respect to a central axis C0 connecting the center C1 of the first optical fiber 67 and the center C4 of the fourth optical fiber 70 at both ends. And the center C3 of the third optical fiber core wire 69 are shifted in the same direction and arranged in a mountain shape.

  Each of the optical fiber cores 67 to 70 has glass fibers 61 to 64 including a core and a clad at the center, and the outer periphery of the glass fibers 61 to 64 is covered with a resin protective coating 65. Each of the optical fiber cores 67 to 70 is covered with a jacket 66 on the outer periphery.

  The optical fiber ribbon 60 has a predetermined gap between the adjacent first optical fiber 67 and the second optical fiber 68 and between the third optical fiber 69 and the fourth optical fiber 70. A bridge portion 71 for forming a gap is provided on the central axes C5 and C6. On the other hand, the bridge portion 71 is not provided between the second optical fiber core 68 and the third optical fiber core 69, and the second optical fiber core 68 and the third optical fiber core 69 are flat. Is in direct contact. Therefore, the optical fiber ribbon 60 has a first optical fiber 67 and a second optical fiber 68, and a third optical fiber 69 and a fourth optical fiber 70 connected by a bridge 71. The second optical fiber core wire 68 and the third optical fiber core wire 69 are connected by a jacket 66, and are integrated in parallel as a whole.

  According to the optical fiber ribbon 60 of the third embodiment described above, one side of the central axis C0 connecting the center C1 of the first optical fiber 67 and the center C4 of the fourth optical fiber 70 at both ends. In addition, the center C2 of the second optical fiber core wire 68 and the center C3 of the third optical fiber core wire 69 are shifted and arranged in a mountain shape. Thus, when the optical fiber ribbon 60 is disposed in the optical fiber alignment groove 32 of the optical fiber holder 30 and pressed from above by the optical fiber holder 30 to be broken into a flat tape shape, each of the optical fibers 67 to The order change of 70 can be avoided reliably (see FIG. 2).

(Fourth embodiment)
Next, an optical fiber ribbon according to the fourth embodiment of the present invention will be described.
As shown in FIG. 6, the optical fiber ribbon 80 according to the fourth embodiment of the present invention is similar to the configuration of the optical fiber ribbon 60 of the above embodiment, and the first optical fiber 87, This is a deformation type tape core consisting of four cores of a second optical fiber core 88, a third optical fiber core 89 and a fourth optical fiber core 90.

  The optical fiber ribbon 80 has a center D2 of the second optical fiber 88 with respect to a central axis D0 connecting the center D1 of the first optical fiber 87 and the center D4 of the fourth optical fiber 90 at both ends. And the center D3 of the third optical fiber core wire 89 are shifted in the same direction and arranged in a mountain shape.

  The optical fiber ribbon 80 has a predetermined gap between the adjacent first optical fiber 87 and the second optical fiber 88 and between the third optical fiber 89 and the fourth optical fiber 90. A bridge portion 91 for forming an interval is provided on the central axes D5 and D7.

  In addition, the optical fiber ribbon 80 is different from the optical fiber ribbon 60 in order to form a relatively long predetermined distance L5 between the second optical fiber 88 and the third optical fiber 89. The bridge portion 91 is provided on the central axis D6. Accordingly, the second optical fiber core 88 and the third optical fiber core 89 are connected in a flat shape by the bridge portion 91 and are connected in parallel as a whole.

  According to the optical fiber ribbon 80 of the fourth embodiment described above, a predetermined interval L5 that is relatively longer than the other bridges is formed between the second optical fiber 88 and the third optical fiber 89. A bridge portion 91 is provided. As a result, the rigidity between the second optical fiber core 88 and the third optical fiber core 89 is greater than that of the other bridge portions when the optical fiber holder 30 is pressed from above and broken into a flat tape shape. ing. Accordingly, it is possible to reliably avoid the order of the optical fiber cores 87 to 90 without causing excessive deformation between the second optical fiber core wire 82 and the third optical fiber core wire 83.

(Fifth embodiment)
Next, an optical fiber ribbon according to a fifth embodiment of the present invention will be described.
As shown in FIG. 7, the optical fiber ribbon 100 according to the fifth embodiment of the present invention is similar to the configuration of the optical fiber ribbon 60 of the above embodiment, and the first optical fiber 107, This is a modified type of tape core consisting of four cores of a second optical fiber core wire 108, a third optical fiber core wire 109, and a fourth optical fiber core wire 110.

  The optical fiber ribbon 100 has a center E2 of the second optical fiber 108 with respect to a central axis E0 connecting the center E1 of the first optical fiber 107 and the center E4 of the fourth optical fiber 110 at both ends. And the center E3 of the third optical fiber core wire 109 are shifted in the same direction and arranged in a mountain shape. Each of the optical fiber cores 107 to 110 is covered with a jacket 106 on the outer periphery.

  The optical fiber ribbon 100 has a predetermined gap between the adjacent first optical fiber 107 and the second optical fiber 108 and between the third optical fiber 109 and the fourth optical fiber 110. A bridge portion 111 for forming an interval is provided on the central axes E5 and E7. On the other hand, the bridge portion 111 is not provided between the second optical fiber core wire 108 and the third optical fiber core wire 109, similarly to the optical fiber tape core wire 60, and the second optical fiber core wire 108 and The third optical fiber core wire 109 is in direct contact with the flat shape.

  In addition, the optical fiber ribbon 100 is different from the optical fiber ribbon 60 in that the connecting portion between the second optical fiber 108 and the third optical fiber 109 is connected by a thick jacket 106. ing. That is, the upper surface and the lower surface of the outer cover 106 of the connecting portion are formed to have a flat thickness. Therefore, the optical fiber ribbon 80 is integrated as a whole in parallel by the jacket 106 and the bridge portion 111.

  According to the optical fiber ribbon 100 of the fifth embodiment described above, the second optical fiber 108 and the third optical fiber 109 are connected by the thick jacket 106. Thus, when the optical fiber holder 30 is pressed from above and broken into a flat tape shape, the second optical fiber core wire 108 and the third optical fiber core wire 109 are flatly and firmly disposed. Therefore, it is possible to reliably avoid changing the order of the optical fiber cores 107 to 110.

(Sixth embodiment)
Next, an optical fiber ribbon according to a sixth embodiment of the present invention will be described.
As shown in FIG. 8, the optical fiber ribbon 120 according to the sixth embodiment of the present invention includes a first optical fiber 131, a second optical fiber 132, a third optical fiber 133, and a fourth optical fiber. The optical fiber core 134, the fifth optical fiber core 135, the sixth optical fiber core 136, the seventh optical fiber core 137, and the eighth optical fiber core 138 are deformed type tape cores.

  The optical fiber ribbon 120 has a second optical fiber 132 and a third optical fiber on one side with respect to a central axis F0 connecting the first optical fiber 131 and the eighth optical fiber 138 at both ends. The three cores of the line 133 and the fourth optical fiber core 134 are arranged so as to be shifted, and the three cores of the fifth optical fiber core 135, the sixth optical fiber core 136 and the seventh optical fiber core 137 are arranged on the other side. By displacing them, the overall arrangement is N-shaped.

  The optical fiber ribbon 120 has a central axis F9 between the first optical fiber 131 and the second optical fiber 132 and between the second optical fiber 132 and the third optical fiber 133. The two bridge portions 139 provided are linearly connected at a predetermined interval. Similarly, between the third optical fiber core wire 133 and the fourth optical fiber core wire 134, between the fourth optical fiber core wire 134 and the fifth optical fiber core wire 135, and between the fifth optical fiber core wire 135 and the sixth optical fiber. The fiber core wires 136 are linearly connected at a predetermined interval by three bridge portions 139 provided on the central axis F10.

  Further, two bridges provided on the central axis F11 are provided between the sixth optical fiber core 136 and the seventh optical fiber core 137 and between the seventh optical fiber core 137 and the eighth optical fiber core 138. The portions 139 are linearly connected with a predetermined interval. Therefore, as a whole, the first optical fiber core 131 to the eighth optical fiber core 138 are integrally connected in an N shape via the seven bridge portions 139.

  According to the optical fiber ribbon 120 of the sixth embodiment described above, the optical fiber cores 132 to 137 other than the first optical fiber core 131 and the eighth optical fiber core 138 at both ends are in the central axis F0. On the other hand, the three cores of the optical fiber core wires 132 to 134 are shifted on one side and the three cores of the optical fiber core wires 135 to 137 are shifted on the other side. Thereby, the direction of the bending rigidity of the tape core wire 120 can be reduced, and it is not necessary to carefully align the tape core wires during the extra length storage operation, and the time required for the extra length storage operation can be reduced.

  In addition, this invention is not limited to embodiment mentioned above, A deformation | transformation, improvement, etc. are possible suitably. In addition, the material, shape, dimension, numerical value, form, number, arrangement location, and the like of each component in the above-described embodiment are arbitrary and are not limited as long as the present invention can be achieved.

1 Optical fiber cable 2 Presser winding 3, 16, 50, 66, 86, 106, 130 Outer jacket 4 Tension member 10, 40, 60, 80, 100, 120 Optical fiber tape core 17, 51, 67, 87, 107 131 First optical fiber core 18, 52, 68, 88, 108, 132 Second optical fiber core 19, 53, 69, 89, 109, 133 Third optical fiber core 20, 54, 70, 90, 110, 134 Fourth optical fiber cores 21, 59, 71, 91, 111, 139 Bridge portion 30 Optical fiber holder 31 Base 32 Optical fiber alignment groove 34 Upper holding lid 55, 135 Fifth optical fiber cores 56, 136 Sixth optical fiber core wire 57, 137 Seventh optical fiber core wire 58, 138 Eighth optical fiber core wire

Claims (6)

An optical fiber ribbon that covers the entire circumference of three or more optical fibers;
An optical fiber ribbon that is arranged so that there is no center of the other optical fiber cores on a central axis that connects the centers of the optical fiber cores at both ends.   A bridge portion thinner than the outer diameter of the optical fiber core including an outer sheath covering the outer periphery of the optical fiber core is provided between at least a pair of the optical fiber cores, and the plurality of optical fiber cores are integrated. The optical fiber ribbon according to claim 1, wherein the optical fiber ribbon is formed.   3. The optical fiber ribbon according to claim 1, wherein a plurality of the optical fibers other than the optical fibers at both ends are alternately displaced with respect to the central axis.   4. The optical fiber ribbon according to claim 1, wherein the center positions of the adjacent optical fibers are sequentially shifted in the width direction of the tape strand. 5.   An optical fiber cable comprising a plurality of the optical fiber ribbons according to any one of claims 1 to 4 assembled in a spacer, a presser winding wound around the outer periphery thereof, and a jacket made of a thermoplastic resin. . A plurality of connection end portions of the optical fiber ribbons according to any one of claims 1 to 5 are arranged on an optical fiber alignment groove of an optical fiber holder of a fusion splicer and pressed by an upper pressing lid of the holder. An optical fiber connecting method comprising: aligning the centers of the optical fiber core wires in parallel in one plane and then performing a fusion splicing connection.

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