Nippon Telegraph and Telephone Corporation

Fujikura Limited

The Furukawa Electric Co., Ltd.

Hitachi-kokusai Electric Inc.

Yuji Aoyagi

Naoki Nakagawa

Takashi Yamaguchi

Keisuke Yoneda

Katsushi Nakayachi

Ken Osato

Kunihiko Fujiwara

Yutaka Hoshino

Kazuhiro Takizawa

Akira Namazue

Mizuki Isaji

Kouji Tomikawa

Kanemi Sasaki

Masatoshi Ohno

Takaharu Matsuda

Shigekatsu Tetsutani

Shinya Hamaguchi

Kazutoshi Takamizawa

Shinnosuke Sato

Mitsuru Muramoto

Tomohiro Ishimura

Yohei Endo

Hung Huu Luong

Yukihiko Shibata

An optical fiber cable includes: a core comprising gathered optical fibers; an inner sheath housing the core; a wire body embedded in the inner sheath; tension members embedded in the inner sheath, wherein the core is interposed between the tension members; a reinforcing sheet that covers the inner sheath; and an outer sheath that covers the reinforcing sheet, wherein in the inner sheath, t&#x3c;Tand t&#x3c;Tare satisfied, where a thickness of a radially inner portion between the core and the wire body is t, a thickness of a radially inner portion between the core and each of the tension members is T, a thickness of a radially outer portion between the wire body and the reinforcing sheet is t, a thickness of a radially outer portion between each of the tension members and the reinforcing sheet is T.

Optical fiber cable

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

A method of manufacturing an optical connector according to the invention includes: holding a first optical fiber by a pair of holding members at a position apart from an end face of a second end and through both sides thereof in a radial direction, the first optical fiber being provided with a solid refractive index-matching material layer, the refractive index-matching material layer being formed on the end face of the second end on an opposite side of an end face of a first end exposed to a front end of a ferrule; and inserting the first optical fiber into a fiber hole of the ferrule through the first end.

Method of manufacturing optical connector, optical connector, and optical fiber insertion device

A holder includes a base including a reference surface and a slider to which an optical-fiber retainer that retains an optical-fiber can be attached. The slider is movable in a front-rear direction with respect to the base, and at least a portion of the optical-fiber retainer is accommodated between the reference surface and the slider when the optical-fiber retainer is attached to the slider and the optical-fiber retainer is positioned with respect to the reference surface by moving the slider toward a reference surface side.

Holder and optical fiber processing method

The present invention is to provide a radio system that enables effective reuse of a limited number of frequencies without the occurrence of interference between subscriber stations. In the radio system according to the present invention, each base station is divided into two or more sectors, each of which is provided with an antenna different in directivity on a horizontal plane. The antennas are so placed that the antenna beams cover all the directions on the horizontal plane as a whole, and all the antennas using the same frequency and polarized wave are so arranged to face in about the same direction.

Radio system

Growing community of inventors

Tsukuba, Japan

Yuji Aoyagi