Nippon Telegraph and Telephone Corporation

The Furukawa Electric Co., Ltd.

Fujikura Limited

Yohei Endo

Hiroaki Tanioka

Shigekatsu Tetsutani

Yuta Maruo

Ken Osato

Naoki Nakagawa

Yutaka Hoshino

Yusuke Yamada

Kouji Tomikawa

Hisashi Izumita

Masatoshi Ohno

Shinya Hamaguchi

Yuji Aoyagi

Tomohiro Ishimura

Yukihiko Shibata

The present disclosure intends to facilitate tearing a metal sheath even in a case where the metal sheath is incorporated in an optical fiber cable. The optical fiber cable of the present disclosure includes a cable core arranged at a central portion and accommodating a plurality of optical fibers gathered together, an inner layer sheath arranged on an outer circumference of the cable core and sheathing the cable core, a metal sheath arranged on an outer circumference of the inner layer sheath and wound around the inner layer sheath, an outer layer sheath arranged on an outer circumference of the metal sheath and sheathing the metal sheath, and at least one outer sheath tearing string arranged in a longitudinal direction inside the metal sheath.

Optical fiber cable

An optical fiber cable includes: a cable body having a core and an inner sheath that accommodates the core; a reinforcing sheet that surrounds the cable body; an outer sheath that accommodates the cable body and the reinforcing sheet; and an outer ripcord that is embedded in the inner sheath. The inner sheath includes a projection that projects outwardly in a radial direction of the optical fiber cable. At least part of the outer ripcord is disposed inside the projection.

Two bundle materials are provided on the outer periphery of a plurality of optical fibers. The bundle materials are twisted back while reversing the winding from front to back and vice versa to thus wind the bundle materials around the plurality of optical fibers. That is, the bundle materials are not wound spirally around the plurality of optical fibers. The bundle materials are bonded at a bonding portion where both bundle materials intersect. The bonding portion is provided along a center line of an optical fiber unit. The bundle materials are arranged in ranges which are each approximately 180&#xb0; and partitioned by the center line.

Optical fiber unit, optical fiber cable, and method for manufacturing optical fiber unit

Growing community of inventors

Tsukuba, Japan

Yohei Endo