JPH1010388A - Coated optical fiber ribbon - Google Patents

Abstract

PROBLEM TO BE SOLVED: To suppress or prevent inducing of work strains caused by differences in the path lengths of respective fibers in the case of forming a cable by imparting larger extra lengths on fibers arranged in the vicinity of both side edges of a coated optical fiber ribbon. SOLUTION: The coated optical fiber 10 comprises a plurality of optical fibers 11a, 11b, 11c... arranged in juxtaposition and an integral coating 12 which is applied in the form of a tape on their circumferences and consist of a UV curing resin, etc. The extra lengths larger with the fibers nearer both side edges are imparted to the respective fibers 11a, 11b, 11c as shown in the upper part of Fig. The occurrence of elongation ought to be exerted on the respective fibers in housing the fibers in twisting grooves 2 formed on the outer periphery of a slot rod 3 of such coated optical fiber ribbon 10 is prevented by the extra lengths previously imparted thereto and, therefore, the pressing of the coated optical fiber ribbon 10 to the wall surfaces of the grooves 2 and the occurrence of irregular bending do not arise any more.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an optical fiber tape obtained by arranging a plurality of optical fiber wires in parallel and coating the outer periphery of the optical fiber tape collectively.

[0002]

2. Description of the Related Art Conventionally, a spacer type optical fiber cable as shown in FIG. 2 has been known as a cable in which many optical fibers are assembled.

[0003] In other words, this cable has an FRP
A plurality of optical fiber wires 4 are arranged in parallel in each groove 2 of the slot rod 3 provided in the outer circumferential surface of the slot rod 3 provided with S twist, Z twist, or SZ twist. Usually, a plurality of optical fiber ribbons 6 having a structure in which a coating 5 of an ultraviolet curable resin or the like is provided on the outer periphery thereof are usually stacked and stored, and a presser winding 7 and a plastic or the like are provided on the outer periphery thereof. It has a structure in which a jacket 8 is provided in order.

[0004]

By the way, in the above-mentioned optical fiber cable, when the optical fiber ribbon 6 is housed in the groove 2, the larger the optical fiber wire 4 located closer to the side edge, the larger the elongation (processing strain). ) Will be added. This is because there is a difference in the path length of each optical fiber wire 4, and the path length becomes longer as the optical fiber ribbon wire 6 is located closer to the outside, for example, as shown in FIG. Comparing the path lengths of the optical fiber strand 4a and the optical fiber strand 4b further outward, the distance r 'of the outward strand 4b from the center of the slot rod 3 is equal to the distance of the center strand 4a.
Is longer than the distance r from the center of the slot rod 3 of
Inevitably, the outer wire 4b has a path length of the center wire 4
It is longer than that of a. As a result, a larger tension is applied to the outer strand 4b than to the center strand 4a, and the elongation increases.

However, the conventional optical fiber ribbon 6
In the above, since no consideration was given to the occurrence of the elongation of the strand due to such a difference in path length, the optical fiber strand 4 nearer to the side edge is subjected to greater elongation, and the optical fiber ribbon 6 is There has been a problem that the transmission characteristics of the optical fiber are degraded due to being pressed against a wall surface or causing irregular bending.

The present invention has been made in view of such a point, and it is possible to prevent the occurrence of processing distortion due to a difference in path length of each wire when a cable is formed, thereby improving the transmission characteristics of the cable. An object of the present invention is to provide an optical fiber tape.

[0007]

According to the present invention, there is provided an optical fiber tape having a plurality of optical fiber wires arranged in parallel and having an outer periphery coated collectively. It is characterized in that the ones that are arranged closer to are given a larger extra length.

[0008] In such an optical fiber tape core wire, when it is housed in a twist groove formed on the outer peripheral surface of a slot rod for a spacer type optical fiber cable, a side edge where a path length difference becomes large is formed. The closer the strand, the greater the extra length is given in advance, so that the occurrence of elongation due to such a difference in path length is suppressed. Therefore, a spacer type optical fiber cable having good transmission characteristics and high reliability can be obtained.

In the present invention, in particular, the extra length given to the optical fiber is set to the length of each optical fiber when the optical fiber tape is accommodated in the twist groove formed on the outer peripheral surface of the slot rod. Therefore, it is possible to almost completely suppress the occurrence of the elongation due to the difference in the length of the strands, so that the reliability of the cable can be further improved.

[0010]

Embodiments of the present invention will be described below in detail with reference to the drawings. FIG. 1 is a view showing an example of an optical fiber tape according to the present invention. As shown in FIG. 1, the optical fiber tape 10 includes a plurality of parallel optical fiber wires 11a, 11b, 11c. ... and a batch covering 1 made of a UV-curable resin or the like applied in a tape shape around it
And 2. Then, each optical fiber 11
As shown in the upper part of the drawing, a larger margin is given to a, 11b, 11c,. That is, for example, when this is accommodated in the twisted groove 2 formed on the outer peripheral surface of the slot rod 3 for the spacer type optical fiber cable as shown in FIG. 2, each of the optical fiber wires 11a, 11b, 11c ... The remaining lengths substantially matching the path length differences of the optical fiber strands 11a, 11b, 11c ...
…….

In such an optical fiber tape 10, the twist groove 2 formed on the outer peripheral surface of the slot rod 3 is formed.
Since the extension which would be applied to each of the strands when stored in the optical fiber is prevented by the extra length given in advance, the optical fiber tape core 10 is pressed against the wall surface of the groove 2 or an irregular bending occurs. Will not occur. Therefore, it is possible to provide a spacer type optical fiber cable having excellent transmission characteristics and high reliability.

Each of the optical fibers 11a, 11b,
11c is, for example, an optical fiber cable.
When the core wire 10 is manufactured, the individual wires 11a, 11b, 11c,.
.. Can be given by adding a predetermined back tension to each. That is, the closer to the both side edges, the greater the back tension may be applied.

The above-mentioned example is an example in which the present invention is applied to an optical fiber tape having a structure in which the wires are arranged in a single layer. The present invention is applicable to a multilayer structure. In this case, for example, when housed in the twisted groove of the slot rod, based on the strand having the shortest path length, a difference in path length from this strand is given to each of the other strands as an extra length. What should I do?

[0014]

As described above, in the optical fiber tape according to the present invention, since the strands arranged closer to the both side edges have a larger surplus length, the optical fiber tape core in the case where the cable is formed into a cable. Occurrence of processing distortion due to the difference in path length between the individual wires is suppressed or prevented. Therefore, a spacer type optical fiber cable having good transmission characteristics and high reliability can be obtained.

In particular, when the extra length of the path length difference is given to the strand, the occurrence of processing distortion can be almost completely prevented, so that it is possible to obtain a spacer type optical fiber cable having more excellent transmission characteristics. it can.

[Brief description of the drawings]

FIG. 1 is a view showing an example of an optical fiber tape cord according to the present invention.

FIG. 2 is a cross-sectional view showing an example of a spacer type optical fiber cable to which the optical fiber tape of the present invention is applied.

FIG. 3 is an essential part cross-sectional view showing a state where an optical fiber tape is accommodated in a twist groove of a slot rod of a spacer type optical fiber cable.

[Explanation of symbols]

 2 Groove 3 Slot rod 6, 10 Optical fiber ribbon 11a, 11b, 11c Optical fiber 12

Claims (2)

[Claims] 1. An optical fiber tape having a plurality of optical fiber strands arranged in parallel and having an outer periphery coated collectively, wherein the optical fiber strands are arranged closer to both side edges. An optical fiber tape having a larger surplus length. 2. The optical fiber tape according to claim 1, wherein the extra length given to the optical fiber is a length of the optical fiber tape.
An optical fiber tape, wherein the optical fiber tape corresponds to a path length difference of each optical fiber when the optical fiber is housed in a twist groove formed on an outer peripheral surface of a slot rod.