JPH1144833A - Optical fiber - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain a coated fiber which has a high degree of freedom on bending and allows the easy conduction of wiring work by forming both ends of the coated optical fiber as a pair of coated fiber ribbon parts formed by lining up optical fibers in parallel and integrally fixing the same and forming the intermediate part of the coated optical fiber as loose coated fiber parts where the respective optical fibers are separated. SOLUTION: The coated optical fiber 1 is formed as the 8-fiber coated optical fiber. The one end and the other end of the coated optical fiber 1 are formed as a pair of the coated fiber ribbon parts 4 formed by lining up both ends 8 pieces of the optical fibers 2 in parallel and integrally fixing the same. The part between the respective coated fiber ribbon parts 4, i.e., the intermediate part of the coated optical fiber 1, is formed as the loose coated fiber part 5 where the respective optical fibers 2 are separated. The respective optical fibers 2 are held separated in this coated fiber parts 5 and the respective optical fibers 2 exist as respectively independent single coated fibers. Then, the coated optical fiber 1 may be curved in a desired direction without exerting undue tensile force and side pressure thereon.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an optical fiber core in which a plurality of optical fibers are bundled at high density.

[0002]

2. Description of the Related Art Conventionally, as a form of an optical fiber core, a type generally called a tape core is known.
This tape core wire is made by arranging a plurality of optical fiber wires in parallel and applying a coating made of an ultraviolet curable resin or the like to the whole and fixing them together, or a single core having a coating made of an ultraviolet curable resin or the like. Are formed on a very thin plastic sheet to form a tape-shaped optical fiber core.

[0003]

However, the conventional optical fiber ribbon (tape ribbon) has the following problems since it is configured as described above.

[0004] That is, since the tape core wire has a flat structure with a certain width by arranging a plurality of optical fiber wires in parallel, it is easy to bend in the thickness direction. It is difficult to bend in the width direction.
Further, when the optical fiber is bent in the width direction, a tensile force or a lateral pressure due to the coating is applied to the optical fiber in the coating, which may damage the optical fiber or increase light loss. Therefore, when wiring the tape core wire, the bending in the width direction of the tape core wire is limited. For this reason, for example, in the case of arranging the tape cores in a spiral pattern or in the case of intersecting the tape cores, a large space is required because the height increases. Therefore, it has been difficult to wire the tape in a narrow space such as between boards in a computer or a telephone exchange. Therefore, an object of the present invention is to provide an optical fiber core wire which has a high degree of freedom in bending and which can facilitate wiring work.

[0005]

According to a first aspect of the present invention, there is provided an optical fiber core wire in which a plurality of optical fiber wires are bundled, and both ends of each optical fiber wire are arranged in parallel. And a pair of tape cores which are collectively fixed together, and a loose core which separates each optical fiber between the pair of tape cores.

That is, the optical fiber core has one end and the other end formed as a tape core portion in which fiber strands are arranged in parallel and fixed collectively. An intermediate portion of the fiber core is a loose core in which the optical fibers are separated from each other. Therefore, this optical fiber core has two ends,
Since it functions as a tape core, the optical fiber strands gathered at high density can be simply and efficiently collectively connected to a body to be connected. Also, in the middle part of the optical fiber core, each optical fiber is present as an independent single core, so that the optical fiber core can be moved in the desired direction without applying excessive tension or side pressure. Can be curved. Thereby, when wiring the optical fiber core, the degree of freedom of wiring is improved, and the optical fiber core can be efficiently wired even in a narrow space.

It is preferable that a plurality of tape cores are stacked to form a tape core assembly, and a plurality of loose cores are assembled to form a loose core assembly. That is, an optical fiber core consisting of a pair of tape cores and a loose core is defined as one unit, the tape cores are stacked on each other, and the loose cores are assembled to form an optical fiber. Form. By adopting such a configuration, a large number of optical fiber wires are easily and efficiently gathered at a high density at both ends of the optical fiber core wire, and the optical fiber core wire having high flexibility in bending is provided. Realization becomes possible.

In these cases, a protective member is further provided as a cover for covering each optical fiber of the loose core portion or the loose core portion, and both end portions of the protective member are taped core portions or It is preferable to fix it to the tape core assembly.
By adopting such a configuration, the strength of the entire optical fiber core can be improved, and each optical fiber strand can be protected, so that the workability when wiring the optical fiber core is improved. improves.

Preferably, the protective member is a polyolefin-based heat-shrinkable tube. If such a configuration is adopted, the loose core portion is heated by heating the heat-shrinkable tube in a state where the base end portion of each tape core portion and the loose core portion are accommodated in the heat-shrinkable tube. In this case, the protection member having a circular cross-sectional shape and fixed to the base end of the tape core portion can be easily attached, and workability when attaching the protection member to the optical fiber core is improved.

[0010]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Preferred embodiments of the optical fiber core according to the present invention will be described below in detail with reference to the drawings.

FIG. 1 is an enlarged perspective view of an essential part showing an embodiment of an optical fiber core according to the present invention, and FIG. 2 is a plan view showing the optical fiber shown in FIG. The optical fiber core 1 shown in these drawings is formed as an eight-core optical fiber having eight optical fiber strands 2. One end and the other end of the optical fiber core 1 are a pair of tape cores 4 in which both ends of eight optical fiber strands 2 are arranged in parallel and fixed collectively.

As shown in FIGS. 2 and 3, each tape core portion 4 is formed by coating both ends of eight parallel optical fiber wires 2 with a coating 3 made of an ultraviolet curable resin or the like by a predetermined length. Is formed to be collectively fixed in a flat tape shape. In addition, in this optical fiber core 1,
Although the tape core portion 4 is formed by coating, the optical fibers 2 may be collectively fixed in a tape shape using an epoxy adhesive or the like. Further, a plurality of optical fiber wires 2 each having a coating 3 made of an ultraviolet-curable resin or the like applied to both ends at a predetermined length are used, and the optical fiber wires 2 are aligned on a plastic sheet or the like to form a tape core. The line portion 4 may be formed.

Thus, both ends of the optical fiber core 1 have the same function as a general tape core in which optical fiber strands are gathered at a high density.
Since the collective connection can be easily and efficiently made to the connected object, the connector connection and the fusion connection can be easily performed. The length of the tape core portion 4, that is, the length of applying the coating 3 to both ends of each optical fiber 2 is determined by the purpose of use,
It can be arbitrarily determined according to the place of use or the like.

A loose core portion 5 in which each optical fiber 2 is separated is formed between the tape core portions 4, that is, an intermediate portion of the optical fiber core 1. In the loose core portion 5, as shown in FIG. 4, each optical fiber 2 is in a separated state, and each optical fiber 2 exists as an independent single fiber. . Therefore, the optical fiber 1 can be bent in a desired direction without applying an excessive tensile force or side pressure, and the degree of freedom in wiring the optical fiber 1 can be improved. .

Thus, for example, in the case where the optical fiber is spirally overlapped in a narrow space or wired in an intersecting manner, in the case where the optical fiber is wired so as to intersect, it is impossible to use the conventional optical fiber in the optical fiber in the coating. In order not to apply excessive tensile force or lateral pressure, the tape core must be curved in the thickness direction without twisting in the width direction, and a space is particularly required in the height direction. On the other hand, since the optical fiber core 1 has a high degree of freedom in bending and can be bent without applying excessive tensile force or side pressure to the loose core part 5, the optical fiber core is wired. In this case, the flexibility of wiring is improved, and the optical fiber core can be efficiently wired even in a narrow space.
Further, it is possible to reduce the optical loss when the optical fiber is bent.

Each optical fiber 2 of the loose core portion 5 is
It is covered by a protective member 6 as a covering. In the optical fiber 1, a flame-retardant polyolefin-based heat-shrinkable tube is used as the protective member 6. As a result, the strength of the entire optical fiber core 1 can be improved and each optical fiber 2 can be protected. In this case, the heat-shrinkable tube as the protection member 6 is
Before heating, a material having a somewhat large inner diameter and capable of accommodating eight optical fiber strands 2 with a margin when completely contracted is used. Then, the loose core portion 5 is housed inside the protective member 6 before heating,
The heat-shrinkable tube is heated with both ends of the protection member 6 covering the base end of each of the tape cores 4. This allows
A portion of the protection member 6 covering the loose core portion 5 has a cylindrical shape as shown in FIG. As shown in FIG. 6, both ends of the protection member 6 press the protection member to make close contact with the base end of the tape core portion 4. Thereby, the optical fiber core 1 having high strength and reliably protecting each optical fiber 2 is provided.
Can be easily realized, and workability at the time of mounting the protection member 6 can be improved. The protective member 6 can be omitted depending on the purpose of use, the place of use, and the like.

There are several methods for forming the optical fiber core 1, but one method is to use a general tape core.

In this case, first, for example, eight optical fiber wires 9 having a total length of about 1 m are prepared, and each optical fiber wire 9 is coated to form a general tape core wire. Then, the coating at both ends of the tape core is left for a predetermined length (for example, 10 cm), and the coating at the intermediate part of the tape core is removed. Thus, the portion where the coating is left is the tape core portion 4, and the portion where the coating is removed is the loose core portion 5 from which each optical fiber 9 is separated. By heating the heat-shrinkable tube in a state where the base end portion of each tape core portion 4 and the loose core portion 5 are accommodated in a heat-shrinkable tube as the protective member 6, the optical fiber core is heated. 1
Can be formed.

Further, after using a general tape core wire and removing the coating on the other end portion of the tape core wire while leaving the coating on one end of the tape core wire for a predetermined length, each optical fiber element is removed. The other end of the wire 9 may be collectively fixed in a tape shape to form a pair of tape core portions 4. In this case, it becomes easy to unify each optical fiber 9 buried in the middle part of the tape core. Further, it is also possible to form the tape core portion 4 by arranging a plurality of optical fiber wires and fixing only both portions of each optical fiber wire collectively.

FIG. 7 is an enlarged perspective view of a main part showing another embodiment of the optical fiber core according to the present invention. The optical fiber core 1 </ b> A shown in FIG. 1 is formed as a 40-core optical fiber having 40 optical fibers 2. At one end of the optical fiber core 1A, five tape cores 4 in which both ends of eight optical fiber strands 2 are arranged in parallel and fixed collectively are laminated to form a tape core assembly. The part 7 is formed. Although not shown, a similar tape core assembly 7 is also provided at the other end of the optical fiber core 1A.
Are formed.

As a result, an extremely large number of optical fiber wires 2 can be gathered at a high density at both ends of the optical fiber core wire 1A. Accordingly, each optical fiber 2 can be simply and efficiently connected to the connected object collectively, and connector connection and fusion splicing can be easily performed.

The space between the tape cores 7 is as follows:
In the middle part of the optical fiber core 1A, loose core parts 5 obtained by separating the individual optical fibers 2 are gathered to form a loose core collection part 8. In the loose core assembly 8, each optical fiber 2 exists as an independent single core. Therefore, the optical fiber core 1A can be bent in a desired direction without applying an excessive tensile force or side pressure, and the degree of freedom in wiring the optical fiber core 1A can be improved. .

As described above, the optical fiber core comprising the pair of tape cores 4 and loose cores 5 is defined as one unit.
By laminating the respective tape core portions 5 to form an optical fiber core aggregate in which the loose core portions are assembled,
At both ends of the optical fiber core, a number of optical fiber
It is possible to realize an optical fiber core that can be simply and efficiently assembled at a high density, bend in a desired direction, and reduce optical loss during wiring.

[0024]

According to the present invention, since the optical fiber core is constituted as described above, the following effects can be obtained. In other words, both ends of the optical fiber core are a pair of tape cores in which the optical fibers are arranged in parallel and are collectively fixed, and the middle part of the optical fiber is a loose core in which each optical fiber is separated. Since it is a part, the degree of freedom of bending is high and the wiring work can be facilitated.

[Brief description of the drawings]

FIG. 1 is a perspective view showing an embodiment of an optical fiber core according to the present invention.

FIG. 2 is a perspective view showing the optical fiber ribbon shown in FIG. 1;

FIG. 3 is a sectional view taken along line III-III in FIG. 2;

FIG. 4 is a plan view showing a tape core part and a loose core part.

FIG. 5 is a sectional view taken along line VV in FIG. 2;

FIG. 6 is a sectional view taken along line VI-VI in FIG. 2;

FIG. 7 is a perspective view showing another embodiment of the optical fiber ribbon according to the present invention.

[Explanation of symbols]

1, 1A: optical fiber core, 2: optical fiber, 3 ...
Coating, 4: tape core portion, 5: loose core portion, 6: protective member, 7: tape core portion, 8: loose core portion.

Claims (5)

[Claims] 1. A pair of optical fiber cores in which a plurality of optical fiber strands are bundled, a pair of tape cores in which both ends of each of the optical fiber strands are arranged in parallel and fixed collectively, and the pair of tape cores. An optical fiber core comprising: a loose core portion in which the optical fibers are separated from each other. 2. The apparatus according to claim 1, further comprising a protection member that covers each of the optical fiber wires of the loose core portion, and both ends of the protection member are fixed to the tape core portion. Fiber optic cable. 3. The light according to claim 1, wherein a plurality of said tape core portions are laminated to form a tape core portion, and a plurality of said loose core portions are collected to form a loose core portion. Fiber core. 4. The apparatus according to claim 1, further comprising: a protection member for covering each of the optical fiber wires of the loose core portion, wherein both ends of the protection member are fixed to the tape core portion. 3. The optical fiber cord according to 3. 5. The optical fiber according to claim 3, wherein the protection member is a polyolefin-based heat-shrinkable tube.