JPH075449Y2 - Optical fiber ribbon - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION <Industrial field of application> The present invention is directed to an optical fiber tape core wire in which a plurality of optical fiber wires closely arranged in parallel on the same plane are integrally covered by a common coating layer. It is about.

<Prior Art> FIG. 7 shows a cross-sectional structure of a conventional optical fiber tape core wire, where 1 is an optical fiber tape core wire, 2 is an optical fiber, 3 is an optical fiber element wire, and 4 is an element wire coating. 5 is a common coating layer. The optical fiber ribbon 1 has a structure that enables high-density mounting of the optical fibers 2 in an optical fiber cable without impairing the transmission characteristics and mechanical characteristics of the optical fibers 2. Further, since the optical fibers 2 are arranged on the same plane in an orderly manner, when the optical fiber ribbons 1 are connected to each other, the end faces of the optical fibers 2 are butted at the same time for all the optical fibers 2 by utilizing the arrangement property. Because you can
Since it is possible to connect all at once, the connection time can be shortened. Therefore, it is particularly useful for constructing a multi-core cable.

<Problems to be Solved by the Invention> In an optical fiber cable used for telecommunications, it is necessary to take out an appropriate number of optical fibers near the place where the demand occurs in accordance with the demand of communication service. For this purpose, when the optical fiber ribbon 1 shown in FIG. 7 is divided into appropriate optical fiber core number units (hereinafter referred to as optical fiber units), the common coating layer 5 is made of a uniform material. Therefore, it is not always divided at the center of the optical fiber ribbon 1 and often has a tear-off shape as shown in FIG. 8 (a). For this reason, as shown in FIG. 1B, the common coating layer 5 is particularly missing in the optical fiber element wires 3 located on the division planes of the optical fiber tape core wire 1, and therefore the optical fiber wire core 3 is dropped from the optical fiber tape core wire 1. There was a problem.
If this optical fiber element wire 3 falls off, the optical fiber tape core wire 1 cannot be collectively connected in the unit of the optical fiber unit, or the dropped optical fiber element wire 3 can be protected and handleability such as surplus length treatment is improved. It had the drawback of getting worse.

In view of the above prior art, the present invention can easily divide an optical fiber tape core wire into two parts in the longitudinal direction at an arbitrary position in the longitudinal direction of the optical fiber tape core wire formed by a plurality of optical fibers. An object of the present invention is to provide an optical fiber ribbon which does not drop out of the optical fiber and can be collectively connected by a common collective connecting jig before and after division.

<Means for Solving the Problems> The configuration of the present invention to achieve the above-mentioned object, the optical fiber strand formed by covering the outer circumference of the optical fiber with a concentric circular strand coating is closely parallel to each other on the same plane. Two optical fiber units which are arranged and whose outer periphery is integrally covered with a common coating layer are closely arranged in parallel, and the closely contacted portions of these optical fiber units are integrally formed by an adhesive material. The thickness t of the common coating layer of the optical fiber unit at the portion where the fiber units are in close contact with each other is t ≦ d × 0.1, where d is the outer diameter of the optical fiber strand.

<Operation> According to the present invention having the above-mentioned configuration, since the common coating layer is provided for each optical fiber unit, when the optical fiber unit is divided into two, the optical fiber element wire does not drop, and the optical fiber unit does not drop. Can be treated as an optical fiber ribbon. In addition, since the thickness of the common coating layer at the portion where the two optical fiber units are in close contact is sufficiently smaller than the outer diameter of the optical fiber strand, the distance between all adjacent optical fibers in the optical fiber ribbon Are considered to be the same distance.
Therefore. When using a high-precision optical fiber alignment jig that uses V-grooves in a collective connection of optical fiber ribbons, prepare one type of optical fiber alignment jig in which V-grooves are provided at the same intervals. It can be used in common before and after dividing the core wire.

<Embodiment> An embodiment of the present invention will be described in detail below with reference to the drawings. It should be noted that the same parts as those of the conventional technique are denoted by the same reference numerals, and overlapping description will be omitted.

FIG. 1 is a sectional view of an optical fiber ribbon according to an embodiment of the present invention, in which 6 is an optical fiber unit, 7 is a recess formed between the optical fiber units 6, and 8 is an adhesive material.
The optical fiber tape core wire 11 has four optical fiber wires 3 formed by concentrically applying a plastic wire coating 4 on the outer circumference of the optical fiber 2 and closely arranged in parallel on the same plane. The two optical fiber units 6 formed by applying the common coating layer 5 to each other are closely arranged in parallel, and the recesses 7 formed between the optical fiber units 6 are filled with the adhesive 8 to form two optical fibers. The unit 6 is formed integrally. At this time, the thickness t of the common coating layer 5 at the portion where the two optical fiber units 6 come into close contact is sufficiently smaller than the outer diameter dimension d of the optical fiber element wire t ≦ d × 0.
It is 1.

Ultraviolet curable urethane acrylate or silicon acrylate is effective as a material of the strand coating 4 forming the optical fiber strand 3. As the material of the common coating layer 5, the same material as the wire coating 4 is effective. As the material of the adhesive material 8, the same material as that of the strand coating 4 is effective, but as described below, it is common in that the optical fiber tape core wire 11 is divided into two optical fiber units 6. Coating layer 5
It is effective to apply UV-curable urethane acrylate or silicone acrylate, which has a smaller compressive elastic modulus than the material used for the above, and a compressive elastic modulus of about 1/10 of that of the common coating layer 5 is suitable.

In such an optical fiber tape core wire 11, by applying a force from the outside to the optical fiber tape core wire 11, the optical fiber tape core wire 11 is divided into right and left at a portion of the adhesive material 8 having a mechanical strength weaker than that of the common coating layer 5. However, it is easy to form the two optical fiber units 6.

As a dividing method in this case, as shown in FIGS. 2 (a) and 2 (b), the optical fiber tape core wire 11 centering on the concave portion 7 is used.
By applying a force to the right and left parts of the adhesive 8 in different directions A and A'by the shearing tools 9a and 9b, a shearing force is applied to the adhesive material 8 to divide the adhesive material 8. It can be used and the construction method is simple and effective. Further, when the optical fiber tape core wire 11 is divided, the entire optical fiber element wire 3 of the optical fiber unit 6 is further covered with the common coating layer 5, so that it should be treated as an independent optical fiber tape core wire. In addition, the optical fiber strand 3 does not fall off.

Further, the optical fiber ribbon 11 has good collective connectivity before and after the division. That is, as shown in FIG. 3, when the two optical fiber ribbons 11 are connected to each other, it is possible to connect the end faces of all the optical fibers 2 by butting them at the same time. This is because the thickness t of the common coating layer 5 at the portion where the two optical fiber units 6 come into close contact with each other is sufficiently small, so that the distance between the centers of all the adjacent optical fibers 2 in the optical fiber ribbon 11. This is because the structure is such that When the optical fibers 2 of the optical fiber ribbons 11 are butted together in a collective connection, an optical fiber axis aligning jig 12 provided with V grooves 10 at a constant pitch is usually used as shown in FIG. The optical fiber 2 exposed by removing the common coating layer 5 and the strand coating 4 at the end of the optical fiber ribbon 11 is placed in the V groove 10 and butted.

At this time, if the thickness t of the common coating layer 5 at the portion where the two optical fiber units 6 are in close contact is not sufficiently smaller than the outer diameter of the optical fiber element wire 3, as shown in FIG. Two optical fibers located in the center of the optical fiber ribbon 11.
The distance between the two optical fibers 2 and 2 becomes larger than the distance between the other adjacent optical fibers 2 and, as a result, the central optical fiber 2,
2 is V in an extremely bent state compared to other optical fibers 2.
It will be placed in the groove 10. The end faces of the central optical fibers 2, 2 arranged in this way are retracted toward the optical fiber tape core 11 side from the end faces of the other optical fibers 2, and in this state, fusion splicing due to discharge or When the connector connection is made by butting the two end faces,
The connection loss becomes large, or the connection fails. Further, if the distance between the optical fibers 2 and 2 at the central portion is extremely large, it is difficult to even arrange the optical fibers in the V groove 10. The common coating layer 5 in the portion where the two optical fiber units 6 are in close contact
As a condition that the thickness t of the
It was clarified in the experiment that the outer diameter d is less than 10%.
Furthermore, in the optical fiber tape core wire 11, as described above, the divided optical fiber unit 6 can be handled as an independent optical fiber tape core wire, so that the optical fiber units 6 can be easily connected together. .

The dimensions of the optical fiber ribbon 11 are as follows: the outer diameter of the optical fiber 2 is 125 μm, the outer diameter of the optical fiber element wire 3 is 250 μm, and the thickness of the common coating layer 5 excluding the portions where the two optical fiber units 6 are in close contact. It has been experimentally clarified that the thickness t of the common coating layer 5 at the portion where the two optical fiber units 6 are in close contact is 25 μm or less.

FIG. 6 is a sectional view of another embodiment of the optical fiber ribbon according to the present invention. In this optical fiber tape core wire 21, four optical fiber wires 3 formed by concentrically applying a plastic wire coating 4 to the outer circumference of the optical fiber 2 are closely arranged in parallel on the same plane. Two optical fiber units 6 formed by applying a common coating layer 5 on the outer periphery are closely arranged in parallel, and the outer periphery of these optical fiber units 6 is further coated with an adhesive 8 to form two optical fiber units. 6 is formed integrally. The thickness of the common coating layer 5 at the portion where the two optical fiber units 6 come into close contact is sufficiently smaller than the outer diameter of the optical fiber element wire 3. The applied material is the same as that of the embodiment shown in FIG.

This embodiment basically has the same structure as the embodiment shown in FIG. 1, but the adhesive 8 embedded in the recess 7 provided on the surface of the common coating layer 5 is used for the entire surface of the optical fiber ribbon 21. It is a thin cover. In this optical fiber tape core wire 21, since the adhesive material 8 covers the entire core wire, it can be formed with a stable structure, and the stability of the structure after formation can be maintained.

<Effects of the Invention> The following effects are obtained by the present invention.

It is possible to provide an optical fiber ribbon which can be easily divided into two. Therefore, in the wiring of the optical fiber, it is possible to improve the degree of freedom of the number of wiring cores.

Even when the optical fiber ribbon of the present invention is divided into two optical fiber units, unnecessary division (dropping of the optical fiber strand) can be prevented, so that the optical fiber unit can be handled as an optical fiber ribbon and It is possible to make a collective connection even after the fiber tape core wire is divided. In this case, since the thickness of the common coating layer in the close contact portion of the two optical fiber units is sufficiently smaller than the outer diameter of the optical fiber strand, the deviation of the distance between all adjacent optical fibers is It can be suppressed within an allowable range in terms of collective connection, and can be collectively connected by using a common optical fiber axis alignment jig before and after dividing the optical fiber ribbon.

[Brief description of drawings]

FIG. 1 is a sectional view showing an embodiment of the optical fiber ribbon according to the present invention, FIG. 2 is an explanatory view conceptually showing a method of dividing the optical fiber ribbon, and FIG. Explanatory drawing which shows notionally the mode at the time of collective connection of the tape core wire, FIG. 4 is sectional drawing which shows the optical fiber fixing jig used for arranging optical fibers at the time of collective connection of the optical fiber tape core wire,
FIG. 5 is an explanatory view conceptually showing a problem when the optical fiber ribbon is arranged on an optical fiber fixing jig, FIG. 6 is a sectional view showing another embodiment of the present invention, and FIG. Is a sectional view of a conventional optical fiber tape core wire, and FIG. 8 is a sectional view of a conventional optical fiber tape core wire divided into two parts. In the drawing, 1,11,21 are optical fiber ribbons, 2 are optical fibers, 3
Is an optical fiber strand, 4 is a strand coating, 5 is a common coating layer, 6
Is an optical fiber unit, 7 is a recess, and 8 is an adhesive.

Claims (1)

[Scope of utility model registration request] 1. An optical fiber formed by covering an outer circumference of an optical fiber with a concentric circular wire coating is closely arranged in parallel on the same plane, and its outer circumference is integrally covered with a common coating layer. The two optical fiber units are closely arranged in parallel, and the close parts of these optical fiber units are integrally formed by an adhesive material, and the common coating layer of the optical fiber units at the parts where the optical fiber units are in close contact with each other. The thickness t of the optical fiber ribbon is t ≦ d × 0.1, where d is the outer diameter of the optical fiber strand.