Intermittent adhesive type optical fiber ribbon core wire, optical fiber cable, and method for manufacturing intermittent adhesive type optical fiber ribbon core wire

Abstract

To provide an intermittent adhesion type optical fiber tape core wire that is excellent in post-branching workability and fusion workability.SOLUTION: An optical fiber tape core wire 3 is adhered by adhesion parts 21 intermittently arranged with adjacent optical fiber strands 17a, 17b, ..., 17l at prescribed intervals in a longitudinal direction of the optical fiber tape core wire 3. The adhesion parts 21 of the adjacent optical fiber strands are arranged, for example, in a zigzag manner with respect to the longitudinal direction of the optical fiber tape core wire 3. In the optical fiber tape core wire 3 with a prescribed length, a length of the optical fiber strands themselves is not fixed. For example, if the adjacent optical fiber strands themselves are mutually adhered so as to be the same length in a case where the length of the adjacent optical fiber strands themselves is different, a slack by an excess length is formed in the optical fiber strand with a longer length, that is, the slack is formed in at least a part of the optical fiber strands.SELECTED DRAWING: Figure 2

Description

[Technical field]

[0001] The present invention relates to an intermittently bonded optical fiber ribbon in which a plurality of optical fiber strands are arranged in parallel and bonded intermittently in the longitudinal direction. [Background technology]

[0002] As an optical fiber for transmitting a large amount of data at high speed, an optical fiber ribbon is used in which multiple optical fiber strands are arranged in parallel and adjacent optical fiber strands are bonded together to simplify storage in a cable and work. Optical fiber ribbons include those in which parallel optical fiber strands are fixed over their entire length with resin, and those in which optical fiber strands are intermittently bonded together in the longitudinal direction. Intermittent bonding of optical fiber strands has the characteristics of improving the wire collection density, reducing transmission loss due to bending, and making it easier to make them single-core.

[0003] When using such an intermittently bonded optical fiber ribbon, it is necessary to perform a post-branching operation to separate the ribbon into individual single-core optical fibers. As a method for separating the ribbon into single-core optical fibers, for example, there is a method using a single-core separation tool made of a brush body made of multiple linear members bundled together (Patent Document 1). [Prior art documents] [Patent documents]

[0004] [Patent Document 1] JP 2012-027200 A Summary of the Invention [Problem to be solved by the invention]

[0005] By using the single-fiber separation tool of Patent Document 1, it is possible to break the bonded portions between the optical fiber strands, and therefore it is possible to separate the intermittently bonded optical fiber ribbon.

[0006] However, even with the method of Patent Document 1, when the optical fiber element wires are neatly aligned, it is difficult for the tip of the brush body to enter the gap between the optical fiber element wires, and the post-branching operation is not necessarily easy.

[0007] On the other hand, when fusion-connecting an optical fiber ribbon core wire, it is necessary to hold the optical fiber ribbon core wire with a holder and arrange the optical fiber element wires exposed from the holder in the V-grooves formed in the holding part of the fusion splicer, respectively. However, if the optical fiber element wires are not neatly aligned, it becomes difficult to arrange the optical fiber element wires in the V-grooves. Therefore, considering the fusion splicing workability, it is desirable to align the optical fiber element wires as neatly as possible.

[0008] The present invention has been made in view of such problems, and an object thereof is to provide an intermittent adhesion type optical fiber ribbon core wire and the like that are excellent in post-branching workability and fusion splicing workability.

Means for Solving the Problems

[0009] In order to achieve the above-described object, a first invention is 12 an optical fiber ribbon core wire in which two or more optical fiber element wires are arranged in parallel, and adjacent The optical fiber element line , the intermittently adhered by an adhesive portion formed at a predetermined interval in the longitudinal direction of the optical fiber ribbon core wire, from the for a predetermined length of the the optical fiber ribbon core wire at , when removing the adhesive portion to divide the optical fiber tape core wire into a plurality of the optical fiber strands, at least one the optical fiber element line length is the same as the length of at least a part of the other optical fiber strands not , among all the optical fiber strands, such that the difference between the length of the shortest one of the optical fiber element wires and the length of the longest one of the optical fiber element wires is 0.06 % or more and less than 0.1% with respect to the length of the shortest one of the optical fiber element wires, in a state of being intermittently adhered by the adhesive portion, and a slack is formed in at least a part of the optical fiber element wires, and it is an intermittent adhesion type optical fiber ribbon core wire.

[0010] The shortest of the optical fiber element wires is arranged at the center in the parallel direction of the optical fiber element wires, and the longest of the optical fiber element wires is arranged at the outermost part in the parallel direction of the optical fiber element wires , from the center to the outermost part in the parallel direction of the optical fiber strands, the lengths of the optical fiber strands may be arranged so as to increase in order.

[0011] The longest optical fiber strand may be arranged at the center in the parallel direction of the optical fiber strands, the shortest optical fiber strand may be arranged at the outermost part in the parallel direction of the optical fiber strands, and from the center to the outermost part in the parallel direction of the optical fiber strands, the lengths of the optical fiber strands may be arranged so as to decrease in order.

[0012] Adjacent optical fiber strands may be arranged in the parallel direction of the optical fiber strands such that the lengths of the optical fiber strands alternate.

[0013] According to the first invention, since a slack is formed between the optical fiber element wires, when performing the post-branching operation, the brush body can easily enter between the optical fiber element wires, and the separation of the optical fiber element wires is easy. In addition, since the difference between the length of the shortest optical fiber element wire and the length of the longest optical fiber element wire is less than 0.1% with respect to the shortest optical fiber element wire, when setting the optical fiber element wire in the V-groove of the holding member, the optical fiber element wire can be reliably arranged.

[0014] In addition, by arranging the shortest optical fiber element wire at the center in the parallel direction of the optical fiber element wires and arranging the longest optical fiber element wire at the outermost part in the parallel direction, it is possible to easily form a slack between the outermost optical fiber element wires. By doing so, the slack can be formed so as to expand in the width direction, and the insertion of the brush body becomes easy.

[0015] In addition, by arranging the optical fiber element wires so that the lengths of the optical fiber element wires increase in order from the center to the outermost part in the parallel direction of the optical fiber element wires, a slack can be efficiently formed between all adjacent optical fiber element wires.

[0016] Such an effect is particularly effective for an intermittently bonded type optical fiber ribbon core wire composed of 12 or more optical fiber element wires.

[0017] The second invention is an optical fiber cable using the intermittently bonded type optical fiber ribbon core wire according to the first invention, wherein a plurality of the intermittently bonded type optical fiber ribbon core wires are twisted together For Optical fiber unit example , a plurality of the optical fiber units are twisted together For core part example , a holding member is wound longitudinally around the outer periphery of the core part For An optical fiber cable comprising a cable core, a tension member disposed outside the cable core, and an outer sheath covering the cable core and the tension member.

[0018] According to the second invention, an optical fiber cable excellent in post-branching workability and fusion workability can be obtained.

[0019] The third invention is A method for manufacturing an intermittently adhered type optical fiber tape core wire according to the first invention, wherein the From the supply part of the optical fiber element wire the To the winding part of the optical fiber tape core wire, each the A predetermined tension is applied to the optical fiber element wires, and at least a part of the The tension of the optical fiber element wire 、 Other the Is adjusted to be different from the tension of the optical fiber element wire and, 12 or more optical fiber strands are arranged in parallel, an adhesive is applied at a predetermined interval, and adjacent optical fiber strands are connected This is a method for manufacturing an intermittently adhered type optical fiber tape core wire, characterized in that.

[0020] According to the third invention, an intermittently adhered type optical fiber tape core wire excellent in post-branching workability and fusion workability can be obtained.

Effects of the Invention

[0021] According to the present invention, an intermittently adhered type optical fiber tape core wire excellent in post-branching workability and fusion workability can be provided.

Brief Description of the Drawings

[0022]

FIG. 1

FIG. 2

FIG. 3

FIG. 4

Embodiments for Carrying Out the Invention

[0023] Hereinafter, embodiments of the present invention will be described with reference to the drawings. FIG. 1 is a cross-sectional view of an optical fiber cable 1. The optical fiber cable 1 is a slottedless cable that does not use slots, and is composed of a cable core 15, a tension member 9, an outer sheath 13, and the like.

[0024] The cable core 15 has a core portion 4 having a substantially circular outer shape and composed of a plurality of optical fiber ribbon cores 3, and a pressing winding member 7 wound around the outer periphery of the core portion 4. The core portion 4 is formed by twisting a plurality of optical fiber units 5. Further, the optical fiber unit 5 is formed by twisting a plurality of optical fiber ribbon cores 3. Details of the optical fiber ribbon core 3 will be described later.

[0025] As described above, a pressing winding member 7 is wound around the outer periphery of the core portion 4. The pressing winding member 7 is a tape-like member or a non-woven fabric, etc., and is arranged so as to collectively cover the outer periphery of the core portion 4 by, for example, longitudinal winding. That is, the longitudinal direction of the pressing winding member 7 substantially coincides with the axial direction of the optical fiber cable 1, and the width direction of the pressing winding member 7 is wound longitudinally around the outer periphery of the plurality of optical fiber units 5 so as to be in the circumferential direction of the optical fiber cable 1. Note that a pressing winding string (not shown) or the like is wound around the outer periphery of the pressing winding member 7 to suppress the opening of the pressing winding member 7.

[0026] In a cross-section perpendicular to the longitudinal direction of the cable core 15, tension members 9 are provided on both sides of the cable core 15. That is, a pair of tension members 9 are provided at positions facing each other with the cable core 15 interposed therebetween. Further, a tearing string 11 is provided so as to face each other with the cable core 15 interposed therebetween in a direction substantially orthogonal to the facing direction of the tension members 9.

[0027] An outer jacket 13 is provided on the outer periphery of the cable core 15. The tension member 9 and the tear cord 11 are embedded in the outer jacket 13. That is, the outer jacket 13 is provided so as to cover the cable core 15, the tension member 9, etc. The outer shape of the outer jacket 13 is substantially circular. The outer jacket 13 is, for example, a polyolefin-based resin. Note that the arrangement and the number of the tension member 9 and the tear cord 11 are not limited to the illustrated example.

[0028] Next, the optical fiber ribbon core 3 will be described. FIG. 2(a) is a plan view of the optical fiber ribbon core 3. The optical fiber ribbon core 3 is configured by arranging a plurality of optical fiber element wires 17a, 17b, ···, 17l in parallel and bonding them. In the present invention, each single-core optical fiber core constituting the optical fiber ribbon core 3 is simply referred to as an optical fiber element wire. The optical fiber element wires 17a to 17l are, for example, those obtained by providing a coating layer and a coloring layer on the outer periphery of a bare optical fiber having an outer diameter of 0.125 mm to make the outer diameter 0.2 mm.

[0029] In this embodiment, an example in which the optical fiber ribbon core 3 is composed of 12 optical fiber element wires 17a to 17l is shown, but the present invention is not limited to this. The number of optical fiber element wires is not particularly limited as long as it is an optical fiber ribbon core in which three or more optical fiber element wires are arranged in parallel. However, the present invention is particularly effective in the case of an optical fiber ribbon core composed of 12 or more optical fiber element wires.

[0030] In the optical fiber ribbon core 3, adjacent optical fiber element wires 17a, 17b, ···, 17l are bonded by adhesive portions 21 that are intermittently arranged at a predetermined interval in the longitudinal direction of the optical fiber ribbon core 3. The adjacent adhesive portions 21 in the parallel direction of the optical fiber element wires are arranged at positions shifted in the longitudinal direction of the optical fiber ribbon core 3.

[0031] That is, the adhesion positions (adhesive portions 21) of the optical fiber ribbon core wire 3 with respect to the longitudinal direction are substantially the same positions between adjacent optical fiber strands 17a and 17b, between optical fiber strands 17c and 17d, between optical fiber strands 17e and 17f, between optical fiber strands 17g and 17h, between optical fiber strands 17i and 17j, and between optical fiber strands 17k and 17l. Similarly, the adhesion positions (adhesive portions 21) of the optical fiber ribbon core wire 3 with respect to the longitudinal direction are substantially the same positions between adjacent optical fiber strands 17b and 17c, between optical fiber strands 17d and 17e, between optical fiber strands 17f and 17g, between optical fiber strands 17h and 17i, and between optical fiber strands 17j and 17k. Further, the adhesion positions (adhesive portions 21) between adjacent optical fiber strands such as between optical fiber strands 17a and 17b and the adhesion positions (adhesive portions 21) between adjacent optical fiber strands such as between optical fiber strands 17b and 17c are shifted by approximately half a pitch in the longitudinal direction and are arranged, for example, in a staggered pattern.

[0032] Note that all of the respective adhesive portions 21 between adjacent optical fiber strands with respect to the longitudinal direction of the optical fiber ribbon core wire 3 are formed at substantially the same pitch. For this reason, when the optical fiber ribbon core wire 3 is laid, etc., the arrangement of the optical fiber strands is not disturbed.

[0033] In the optical fiber ribbon core wire 3 of a predetermined length, the lengths of the optical fiber strands are not constant. Thus, when adjacent optical fiber strands with different lengths are adhered to each other so that the positions of the ends are aligned to have the same length, slack corresponding to the extra length is formed in the longer optical fiber strand. That is, slack is formed in at least some of the optical fiber strands.

[0034] FIG. 2(b) is a diagram showing a state in which the adhesive portion 21 is removed from the optical fiber ribbon core wire 3 having a predetermined length (the optical fiber ribbon core wire 3 having a predetermined length from the end). As described above, the lengths of the optical fiber strands 17a to 17l are not the same. In the illustrated example, the lengths of the optical fiber strands are arranged in order of increasing length from the center to the outermost part in the parallel direction of the optical fiber strands. That is, the shortest optical fiber strands 17f and 17g are arranged in the center in the parallel direction of the optical fiber strands, and the longest optical fiber strands 17a and 17l are arranged at the outermost part in the parallel direction of the optical fiber strands.

[0035] At this time, it is desirable that the difference between the lengths of the shortest optical fiber strands 17f and 17g (A in the figure) and the lengths of the longest optical fiber strands 17a and 17l (B in the figure) is 0.01% or more and less than 0.1% with respect to the lengths of the shortest optical fiber strands 17f and 17g. If the difference in length is too small, sufficient slack cannot be formed, and the effect of the present invention becomes small.

[0036] On the other hand, if the difference in length becomes too large, the slack becomes too large, and the workability of setting the optical fiber ribbon core wire in the fusion splicer during the fusion splicing operation deteriorates. As described above, usually, when fusion splicing the optical fiber ribbon core wire, it is necessary to set the optical fiber ribbon core wire in a holder, set the holder in the fusion splicer, and arrange the tips of the respective optical fiber strands protruding from the tip of the holder in the V-grooves formed in the holding portion of the fusion splicer. At this time, if the slack is large, the optical fiber strands exposed from the holder are likely to move violently, and it becomes difficult to arrange them in the V-grooves. Therefore, it is desirable that the difference in length is less than 0.1%.

[0037] Next, a method for manufacturing an intermittent adhesive type optical fiber ribbon core wire 3 for connecting adjacent optical fiber strands will be described. FIG. 3 is a diagram showing a schematic configuration of a tape core wire manufacturing apparatus 30. As described above, the number of the optical fiber ribbon core wires 3 is not particularly limited as long as three or more optical fiber strands are arranged in parallel. In the following description, a case of manufacturing an optical fiber ribbon core wire 3 by integrating 12 optical fiber strands 17a to 17l in a tape shape will be described.

[0038] The tape core wire manufacturing apparatus 30 mainly comprises a supply drum 31, a resin coating device 37, a curing device 39, a tension detection device 41, a take-up device 43, a winding drum 45, etc. From the 12 supply drums 31, optical fiber element wires 17a to 17l are individually fed out and paralleled by the resin coating device 37.

[0039] The resin coating device 37 includes a die 33 that maintains the traveling optical fiber element wires 17a to 17l in a parallel state, and a resin supply control unit 35 that controls the discharge amount and discharge timing when discharging an adhesive (connecting resin) from a discharge port formed in the die 33. In the resin coating device 37, each of the optical fiber element wires 17a to 17l fed out from the supply drum 31 is inserted into the die 33, and the adhesive is intermittently applied at a predetermined interval in the longitudinal direction between adjacent optical fiber element wires.

[0040] The optical fiber element wires 17a to 17l coated with the adhesive by the resin coating device 37 pass through the curing device 39 in a closely parallel state. In the curing device 39, the adhesive applied to the optical fiber element wires 17a to 17l is cured by, for example, ultraviolet irradiation or heat.

[0041] The tension detection device 41 is a sensor that measures the tension of the optical fiber tape core wire 3. Based on the measurement result by this tension detection device 41, a predetermined tension can be applied to the optical fiber element wires 17a to 17l, for example, by controlling the feeding speed (brake) of the optical fiber element wires 17a to 17l in the supply drum 31.

[0042] The take-up device 43 (capstan roller) has its rotation speed controlled by a control device. The traveling speed of the optical fiber tape core wire 3 is adjusted by the rotation speed of the take-up device 43. Also, the rotation speed of the take-up device 43 is input to the resin supply control unit 35 of the resin coating device 37 as a signal (traveling speed signal) indicating the traveling speed of the optical fiber tape core wire 3.

[0043] The optical fiber ribbon core 3 is taken up at a predetermined linear speed by a take-up device 43 and wound around a take-up drum 45. Thus, the optical fiber ribbon core 3 is manufactured.

[0044] Also, a cable core 15 is formed using a plurality of intermittently adhered optical fiber ribbon cores 3 obtained in this way, and by disposing a tension member 9 or the like on the outer periphery of the cable core 15 and covering it with an outer sheath 13, an optical fiber cable 1 can be obtained.

[0045] Here, as described above, a predetermined tension is applied to each optical fiber strand between the supply section of the optical fiber strands of the tape core manufacturing apparatus 30 and the take-up section of the optical fiber ribbon core. At this time, the feeding speed (brake) is adjusted so that different tensions are applied to each supply drum 31, whereby the tensions of the optical fiber strands 17a to 17l can be individually changed. That is, it is possible to adjust the tension of at least some of the optical fiber strands to be different from the tension of other optical fiber strands.

[0046] For example, taking the adjacent optical fiber strands 17a and 17b as an example, the tension of the optical fiber strand 17b is set to be greater than the tension of the optical fiber strand 17a. By applying tension, the optical fiber strand slightly elongates according to the tension. Therefore, after applying and curing the adhesive and then releasing the tension, the optical fiber strand 17a with relatively low tension becomes slightly longer in length than the optical fiber strand 17b with relatively high tension.

[0047] The optical fiber strand 17a, which is longer in length than the optical fiber strand 17b, is adhered to the adjacent optical fiber strand 17b with an adhesive at predetermined intervals. Therefore, the extra-length portion of the optical fiber strand 17a becomes slack between the adhesive portions 21. In this way, within the range of the optical fiber ribbon core 3 of a predetermined length, by changing the length of the optical fiber strands, it is possible to form a slack between the adhesive portions 21 formed at predetermined intervals in the longitudinal direction between adjacent optical fiber strands.

[0048] For example, in order to make the lengths of the optical fiber strands increase in order from the center to the outermost part in the width direction of the optical fiber ribbon core wire (the parallel direction of the optical fiber strands), it is only necessary to form a tape in a state where the tension of the optical fiber strands is gradually decreased from the center to the outermost part. If it is possible to form a slack between adjacent optical fiber strands, the manufacturing method is not limited to the above method.

[0049] As described above, according to the present embodiment, since a slack is formed between adjacent optical fiber strands, a gap can be formed between the optical fiber strands due to the slack. Therefore, the tip of the brush body when separating the optical fiber strands can easily enter between the optical fiber strands, and the post-branching operation is easy.

[0050] In addition, since the difference between the length of the shortest optical fiber strand and the length of the longest optical fiber strand is less than 0.1% with respect to the length of the shortest optical fiber strand, the slack does not become too large, and when setting on the fusion machine, it is also easy to arrange each optical fiber strand in its respective V-groove.

[0051] In addition, by making the lengths of the optical fiber strands increase as going from the center to the outside in the width direction (the parallel direction of the optical fiber strands), it is possible to efficiently form a slack between the optical fiber strands. Also, since it is easy to form a slack toward the outside in the width direction, the insertion of the brush body is also easy.

[0052] In addition, when the number of optical fiber strands is 12 or more, usually it becomes difficult to separate the optical fiber strands collectively with a brush body, but the present invention can be effectively applied also to an optical fiber ribbon core wire composed of 12 or more optical fiber strands.

[0053] In the above-described embodiment, the lengths of the optical fiber element wires 17f and 17g at the center in the width direction are made the shortest, and the lengths of the outermost optical fiber element wires 17a and 17l in the width direction are made the longest. However, the present invention is not limited to this. For example, as shown in Fig. 4(a), the lengths of the optical fiber element wires may be arranged so as to gradually decrease from the center to the outermost part in the width direction, with the lengths of the optical fiber element wires 17f and 17g at the center in the width direction being the longest and the lengths of the outermost optical fiber element wires 17a and 17l in the width direction being the shortest.

[0054] Also, as shown in Fig. 4(b), adjacent optical fiber element wires may be arranged so that their lengths alternate between long and short. Regarding the difference in the lengths of adjacent optical fiber element wires, it is desirable that the difference between the length of the relatively short optical fiber element wire and the length of the relatively long optical fiber element wire is 0.01% or more and less than 0.1% with respect to the length of the relatively short optical fiber element wire.

[0055] Also, instead of changing the lengths (tension during manufacturing) of all adjacent optical fiber element wires, if there is a difference in the lengths (tension during manufacturing) of at least some adjacent optical fiber element wires, a slack can be formed at the corresponding site.

Example

[0056] Various intermittent adhesion type optical fiber tape cores were manufactured, and the post-branching workability and fusion workability were evaluated. First, 12-core optical fiber tape cores were prepared and cut to a length of 30 cm. Both ends of the cut optical fiber tape cores were fixed, and a brush body with fine tips was pressed against the optical fiber tape cores and slid in the longitudinal direction of the optical fiber tape cores to remove the adhesive parts.

[0057] The above operation was performed for 100 samples, and a pass was defined as a probability (number of separated adhesive parts / total number of adhesive parts) of 70% or more that the adhesive part was separated in one operation (slide).

[0058] Also, the coating at the end of each optical fiber ribbon core wire was removed with a fiber stripper (S218R-Plus manufactured by Furukawa Electric Co., Ltd.), the fiber end face was prepared with a fiber cutter (S326 manufactured by Furukawa Electric Co., Ltd.), and it was set in a multi-core optical fiber fusion splicer (S124M12 manufactured by Furukawa Electric Co., Ltd.) for fusion splicing.

[0059] After cutting the end face with a fiber cutter, when the tips of 12-core optical fiber ribbon core wires could be set in the V-groove of the fusion splicer in one go without spreading or crossing, it was marked as ○, and when it took two or more attempts, it was marked as ×. After setting 50 times, a case where the probability of ○ was 80% or more was considered a pass. The results are shown in Table 1.

[0060]

Table 1

[0061] In Examples 1 to 4 and Comparative Example 1, as shown in Figure 2, the lengths of the optical fiber strands were changed at a constant rate such that the length of the optical fiber strand increased in order from the center in the width direction to the outside. Note that the "length difference" in the table is (the length difference between the shortest optical fiber strand and the longest optical fiber strand) / (the length of the shortest optical fiber strand) × 100%.

[0062] From the results, in Examples 1 to 4 where the length difference was 0.01% or more and less than 0.1%, the post-branching property was 70% or more in all cases and passed. On the other hand, in the conventional Comparative Example 1 without slack, the post-branching property was 60% and failed. Also, in Examples 1 to 4 where the length difference was 0.01% or more and less than 0.1%, the fusion splicing workability was 80% or more in all cases and passed. On the other hand, in Comparative Example 2 with a large length difference, the probability of being set in one go was 75% and it failed. Thus, Examples 1 to 4 with a length difference of 0.01% or more and less than 0.1% resulted in satisfying both the post-branching property and the fusion splicing workability.

[0063] The embodiments of the present invention have been described above with reference to the attached drawings. However, the technical scope of the present invention is not limited by the above-described embodiments. It is obvious that those skilled in the art can conceive of various modification examples or correction examples within the scope of the technical idea described in the claims, and it is naturally understood that those also belong to the technical scope of the present invention.

Explanation of Reference Numerals

[0064] 1.........Optical fiber cable 3.........Optical fiber tape core wire 4.........Core part 5.........Optical fiber unit 7.........Pressing winding member 9.........Tension member 11.........Tearing string 13.........Outer sheath 15.........Cable core 17a, 17b, 17c, 17d, 17e, 17f, 17g, 17h, 17i, 17j, 17k, 17l.........Optical fiber element wires 21.........Adhesive part 30.........Tape core wire manufacturing apparatus 31.........Supply drum 33.........Die 35.........Resin supply control unit 37.........Resin coating apparatus 39.........Hardening apparatus 41.........Tension detection apparatus 43.........Take-up apparatus 45.........Take-up drum

Claims

1. An optical fiber ribbon core in which 12 or more optical fiber element wires are arranged in parallel, wherein adjacent ones of the optical fiber element wires are intermittently adhered by an adhesive portion formed at a predetermined interval in the longitudinal direction of the optical fiber ribbon core, in the optical fiber ribbon core having a predetermined length from an end, when the adhesive portion is removed and the optical fiber ribbon core is divided into a plurality of the optical fiber element wires, the length of at least one of the optical fiber element wires is not the same as the length of at least a part of the other optical fiber element wires, and among all the optical fiber element wires, the difference between the length of the shortest optical fiber element wire and the length of the longest optical fiber element wire is 0.06% or more and less than 0.1% with respect to the length of the shortest optical fiber element wire, and in a state of being intermittently adhered by the adhesive portion, a slack is formed in at least a part of the optical fiber element wires. An intermittently adhered type optical fiber ribbon core characterized by this.

2. wherein the shortest optical fiber element wire is arranged at the center in the parallel direction of the optical fiber element wires, and the longest optical fiber element wire is arranged at the outermost part in the parallel direction of the optical fiber element wires, The intermittently adhered type optical fiber ribbon core according to claim 1, characterized in that the lengths of the optical fiber element wires are arranged in order of increasing length from the center to the outermost part in the parallel direction of the optical fiber element wires.

3. The longest optical fiber element wire is arranged at the center in the parallel direction of the optical fiber element wires, and the shortest optical fiber element wire is arranged at the outermost part in the parallel direction of the optical fiber element wires, The intermittently adhered type optical fiber ribbon core according to claim 1, characterized in that the lengths of the optical fiber element wires are arranged in order of decreasing length from the center to the outermost part in the parallel direction of the optical fiber element wires.

4. The intermittently adhered type optical fiber ribbon core according to claim 1, characterized in that adjacent ones of the optical fiber element wires are arranged in the parallel direction of the optical fiber element wires such that the lengths of the optical fiber element wires alternate.

5. An optical fiber cable using the intermittently adhered type optical fiber ribbon core according to any one of claims 1 to 4, an optical fiber unit in which a plurality of the intermittently adhered type optical fiber ribbon cores are twisted together, a core portion in which a plurality of the optical fiber units are twisted together, a cable core in which a pressing winding member is longitudinally wound around the outer periphery of the core portion, a tension member arranged outside the cable core, An outer jacket covering the cable core and the tension member, A fiber optic cable characterized by comprising the same. **Claim 6**: A method for manufacturing an intermittent adhesion type optical fiber ribbon core wire according to any one of Claims 1 to 4, wherein a predetermined tension is applied to each of the optical fiber element wires between the supply section of the optical fiber element wires and the winding section of the optical fiber ribbon core wire, and the tension of at least some of the optical fiber element wires is adjusted to be different from the tension of the other optical fiber element wires, A method for manufacturing an intermittent adhesion type optical fiber ribbon core wire, characterized in that 12 or more optical fiber element wires are arranged in parallel, an adhesive is applied at a predetermined interval, and adjacent optical fiber element wires are connected.

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