JPH11258472A - Optical unit and optical cable - Google Patents

Abstract

(57) [Summary] [PROBLEMS] To improve the flexibility of an optical unit in which a plurality of tape cores are stacked and housed in a groove of a long molded body, and to stabilize the transmission characteristics of the optical fiber core. Aim. The groove (5) of a long molded body (5) made of plastic and having a U-shaped cross section and having a groove (5a) formed in the longitudinal direction.
a, a twisted laminated body 4 in which a plurality of optical fiber cores 1 are arranged in parallel and a plurality of tape cores 3 provided with a collective coating 2 are laminated and twisted at a constant pitch in the longitudinal direction. The optical unit 6 is housed. Also, a plurality of the optical units are aligned and twisted around the central body with the opening 5b of the elongated molded body 5 facing outward, and a jacket is provided on the outside to form an optical cable.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a long molded product made of plastic having a groove formed in a longitudinal direction and having a U-shaped cross-section formed therein. And an optical cable using the optical unit.

[0002]

2. Description of the Related Art A plurality of optical units each having an optical fiber core wire housed in a groove of a rectangular spacer having a U-shaped cross section having a groove in a longitudinal direction around a central body are arranged and twisted. The optical cable is known from Japanese Utility Model Laid-Open No. 4-77108.

This optical cable has a cross section as shown in FIG. In order to manufacture this optical cable, a plurality of optical fiber core wires 21 each having a glass fiber coated with an ultraviolet-curable resin or the like are arranged in parallel, and a batch coating 22 made of an ultraviolet-curable resin or the like is applied to form a tape. An optical unit 25 is formed by forming a core wire 23 and stacking a plurality of tape core wires 23 in a groove of a U-shaped rectangular spacer 24 made of plastic such as polyethylene and having a groove.

[0004] Next, an optical unit 25 is arranged around a tension member in which a coating 27 of polyethylene or the like is provided around a steel stranded wire 26 so that the opening of the groove faces outward, and the optical unit 25 is twisted into a suitable presser winding 28. Is applied. If the number of optical units is large, they may be twisted into two layers as shown in FIG. Then, an outer coating 29 made of polyethylene or the like is provided on the outside thereof to obtain an optical cable.

[0005]

An optical unit in which a plurality of tape cores are stacked and housed in a groove of a square spacer,
At the stage of manufacturing the optical unit, the optical unit is once wound around a reel, and at the stage of manufacturing the optical cable, the optical unit is pulled out from the reel and processed into an optical cable. Further, in manufacturing the optical cable, since the openings of the grooves of the square spacers of the optical unit are arranged so as to always face outward, when the optical unit is wound around a reel in manufacturing the optical unit,
The optical unit must be wound around the reel and aligned so that the opening of the groove of the optical unit faces outward in the reel.

However, in the optical unit, since the wide plane of each tape core is parallel to the bottom of the groove of the square spacer,
The flexibility of the optical unit has directionality in cross section. Also, when the optical unit is wound around a reel with the groove opening outside, the bending radius of the tape core near the bottom of the groove and the tape core far from the bottom of the groove in one optical unit is a little. The length of the tape will vary slightly depending on the position of the tape in the laminate.

The difference in length depending on the position of the tape in the laminate depends on the bending radius of the optical unit when the optical unit is manufactured. If the bending radius is different from that of the optical unit when aligned and twisted, there will be a difference in the tension of each tape core in the optical unit, and if it is significant, microbending will occur on the longer tape core. As a result, the transmission characteristics of the optical fiber may deteriorate.

To alleviate this, it is conceivable to increase the body diameter of the reel around which the optical unit is manufactured and wound, but there is a limit to the size of the body diameter of the reel. An object of the present invention is to provide an optical unit having high flexibility which solves the above-mentioned problems of the optical unit according to the prior art, and an optical cable using the same.

[0009]

An optical unit according to the present invention comprises:
A long molded body made of plastic having a groove formed in a longitudinal direction and having a U-shaped cross section, and a tape in which a plurality of optical fiber core wires accommodated in the groove are arranged in parallel and collectively covered. And a twisted laminate in which a plurality of core wires are laminated and twisted in a longitudinal direction at a constant pitch.

An optical cable according to the present invention is characterized in that a long formed body made of plastic having a groove formed in a longitudinal direction and having a U-shaped cross section, and a plurality of tape cores housed in the groove are laminated and fixed. Using an optical unit consisting of a twisted laminate twisted in the longitudinal direction at a pitch, a plurality of the optical units are aligned and arranged around the central body with the openings facing outward, and twisted. An outer coating is provided on the outside.

[0011]

DESCRIPTION OF THE PREFERRED EMBODIMENTS FIG. 1A is a perspective view, an X view, and a Y view showing an embodiment of the optical unit of the present invention.
FIG. 1B is a perspective view of a twisted laminate constituting an embodiment of the optical unit of the present invention. In FIG. 1, reference numeral 1 denotes an optical fiber core obtained by coating a glass fiber with an ultraviolet curable resin or the like, and a plurality of optical fiber cores 1 are arranged in parallel and collectively coated with an ultraviolet curable resin or the like. 2
To give a tape core wire 3. Although the number of optical fiber cores 1 of the tape core 3 is four in FIG. 1, any number may be used as long as the number is plural.

As shown in FIG. 1B, a plurality of tape cores 3 are stacked and laminated, and are twisted at a constant pitch in the longitudinal direction to form a twisted laminate 4. The number of tape cores 3 constituting the twisted laminated body 4 is not limited to five, but may be plural. The direction of the twist is not particularly limited. FIG.
(A) The twisted laminated body 4 is housed in the groove 5a of a long molded body 5 having a U-shaped cross section made of plastic and having a linear groove 5a and an opening 5b in the longitudinal direction as shown in FIG. Unit 6. The outer shape of the elongated molded body 5 having a U-shaped cross section is not limited to the U-shaped one having a smooth lower part, and may be a U-shaped, that is, a rectangular shape, or a trapezoidal shape. The shape of the groove 5a may be a rectangular cross section as long as the size does not hinder the twisting of the twisted laminated body 4 therein. Of course,
In order for the twisted laminate to be smoothly twisted, the groove 5 is required.
a is preferably a U-shaped groove having a smooth bottom.

In the optical unit 6 thus configured, the tape cores are laminated and twisted in the longitudinal direction, so that the tape located outside the lamination with respect to the tape core located in the middle of the lamination. The core wire has a slightly larger bending radius due to twisting, and its length is slightly longer. However, since the tape core wire constituting the twisted laminate is twisted, there is a twisted laminate. Even if the tape is bent at a curvature, no slippage occurs between the tape cores, and no excessive force is applied to the tape cores. Therefore, it has excellent flexibility as an optical unit,
Even when the optical unit is wound around a reel in the manufacture of the optical unit, the transmission characteristics of the optical fiber core do not deteriorate.

FIG. 2 is a sectional view showing an embodiment of an optical cable using the optical unit of the present invention. A plurality of optical units 6 in which the twisted laminated body 4 is housed in the elongated molded body 5 are arranged around the central body 7 such that the grooves of the elongated molded body face outward, and are twisted. The twisting direction may be a method of twisting in one direction, or a so-called SZ twist in which the twisting direction is alternately reversed. In addition, the upper winding 8 and the outer coating 9 are provided on the twisted outer side. The outer coating 9 may be extruded from a plastic such as polyethylene, or may be combined with a metal tape or the like.

The center member 7 is formed by providing a plastic coating such as polyethylene around a tensile member such as a steel wire, a steel stranded wire, or FRP, or a plastic member having a plurality of grooves around the periphery of the tensile member. And an optical unit such as a tape core wire accommodated in the groove, or the optical unit of the present invention in the center of these.
Various forms, such as layers aligned and twisted, are used. If it has a circular cross section,
Either form can be used as the center body 7.

[0016]

The optical unit according to the present invention comprises a long molded body made of plastic having a groove formed in a longitudinal direction and having a U-shaped cross section, and a plurality of optical fiber cores housed in the groove. Are arranged in parallel to form a twisted laminated body obtained by laminating a plurality of tape core wires coated at once and twisting them at a constant pitch in the longitudinal direction, so that they have excellent flexibility and small body diameter. The transmission characteristics of the optical fiber are not deteriorated even when the optical fiber is wound around the reel.

Further, when the optical unit is used as an optical cable, the optical fiber core is formed by the difference between the bending radius of the tape core when manufacturing the optical unit and the bending radius of the tape core when twisted with the cable. The occurrence of microbends in the wire can also be suppressed, and the transmission characteristics of the optical fiber as an optical cable can be stabilized.

[Brief description of the drawings]

FIG. 1A is a perspective view, an X view, and a Y view showing an embodiment of an optical unit of the present invention, and FIG. 1B is a view showing a screw constituting an embodiment of the optical unit of the present invention. FIG. 4 is a perspective view of a turn laminate.

FIG. 2 is a sectional view showing an embodiment of an optical cable using the optical unit of the present invention.

FIG. 3 is a cross-sectional view of a conventional optical cable, an optical unit used for the optical cable, and a tape core.

[Explanation of symbols]

 1: wire 2: batch covering 3: tape core wire 3a: supply reel 4: twisted laminate 5: elongated molded body 5a: groove 5b: opening 6: optical unit 7: central body 8: upper winding 9: Jacket

 ──────────────────────────────────────────────────続 き Continued on the front page (72) Inventor Takashi Saito 1st Tayacho, Sakae-ku, Yokohama-shi, Kanagawa Prefecture Inside the Yokohama Works, Sumitomo Electric Industries, Ltd. (72) Inventor Hideyuki Iwata 3-9-1-2 Nishishinjuku, Shinjuku-ku, Tokyo No. Japan Telegraph and Telephone Corporation

Claims (2)

[Claims] An elongated molded body made of plastic having a groove formed in a longitudinal direction and having a U-shaped cross section, and a plurality of optical fiber cores stored in the groove are arranged in parallel and collectively. An optical unit comprising: a twisted laminated body obtained by laminating a plurality of coated tape core wires and twisting them at a constant pitch in a longitudinal direction. 2. An elongated molded body made of plastic having a groove formed in a longitudinal direction and having a U-shaped cross section, and a plurality of optical fiber cores housed in the groove are arranged in parallel and collectively. An optical unit consisting of a plurality of coated tape cores laminated and twisted in the longitudinal direction at a constant pitch and a twisted laminate, a plurality of each having a central body with the opening of the groove facing outward. An optical cable characterized in that it is arranged and twisted around the periphery and twisted, and an outer coating is provided on the outside thereof.