Fujikura Limited

Nippon Telegraph and Telephone Corporation

Afl Telecommunications Lcc

Akira Namazue

Ken Osato

Tomoaki Kaji

Shogo Shimizu

Go Taki

Yusuke Yamada

Mizuki Isaji

Naoki Okada

Masatoshi Ohno

Shinya Hamaguchi

Hisaaki Nakane

Daisuke Kakuta

Kouji Tomikawa

Soichiro Kaneko

Masayuki Ishioka

Shigekatsu Tetsutani

Shinnosuke Sato

Koji Tomikawa

Okimi Mukai

Yoshie Murakoshi

Naoki Nakagawa

Hiroaki Tanioka

Yuta Maruo

Takashi Matsuzawa

Yukiko Take

Yuji Aoyagi

Akira Murata

Akira Sakurai

Ryo Kuramitsu

Noriaki Yamashita

Hironori Sato

An optical fiber cable includes: a sheath including recesses and protrusions that are alternately disposed in a circumferential direction on an outer circumferential surface of the sheath; a core that includes optical fibers and is accommodated in the sheath; tensile strength members embedded in the sheath; and a ripcord that is embedded in the sheath. A marking portion protruding outward in a radial direction is disposed in the sheath. The ripcord is disposed between the marking portion and the core.

Optical fiber cable

A cable that protects an object includes a sheath and a cylindrical reinforcement member disposed inside the sheath and that surrounds the object. The cylindrical reinforcement member has a first side edge and a second side edge that extend in a longitudinal direction. The cylindrical reinforcement member is formed of a cable reinforcement sheet including a first metal sheet and a second metal sheet joined to the first metal sheet. A portion of the first metal sheet overlaps a portion of the second metal sheet, and the overlapping portions define a joint portion where the first metal sheet and the second metal sheet are joined. The joint portion is inclined, from the second side edge to the first side edge, toward the first metal sheet.

Cable and cable reinforcement sheet

An optical fiber cable includes: a core including optical fibers; a reinforcing wrap that surrounds the core; and a sheath that accommodates the core and the reinforcing wrap. The reinforcing wrap includes an overlapping portion. A first end portion of the reinforcing wrap overlaps a second end portion of the reinforcing wrap at a portion of the reinforcing wrap in a circumferential direction of the optical fiber cable in a cross-sectional view.

Optical fiber cable production method, and optical fiber cable

An optical cable includes optical fiber units each of which includes intermittently-coupled optical fiber ribbons. In at least one of the optical fiber units, in a cross section perpendicular to a longitudinal direction of the at least one of the optical fiber units, a length of a vector GU is shorter than a largest length of vectors MG of the intermittently-coupled optical fiber ribbons forming the at least one of the optical fiber units, where, in each of the intermittently-coupled optical fiber ribbons, each of the vectors MG is a vector starting from M and ending at G, M is a midpoint between optical fibers at both ends of the each of the intermittently-coupled optical fiber ribbons, and G is a center of gravity of the each of the intermittently-coupled optical fiber ribbons, and the vector GU is a resultant vector of the vectors MG.

Optical cable and optical-cable manufacturing method

An optical fiber ribbon includes: optical fibers disposed side by side in a predetermined direction; and connecting portions that connect two adjacent ones of the optical fibers. A peripheral resin portion is formed on a periphery of the optical fibers. An arithmetic mean roughness Ra of a surface of the peripheral resin portion is 0.41 μm or lower. A ten-point mean roughness Rz of a surface of the peripheral resin portion is 1.4 μm or lower.

Intermittently connected optical fiber ribbon

An optical fiber unit according to the present disclosure includes a plurality of intermittently-connected optical fiber ribbons. At least one of the optical fiber ribbons includes a plurality of optical fibers including a first optical fiber, and a second optical fiber that is longer than the first optical fiber. Conditions (AA) and c<0.05 are satisfied, where b is an interval, in a length direction, between connection parts that connect the first optical fiber and the second optical fiber, c (%) is a fiber length difference of the second optical fiber with respect to the first optical fiber, and Y is an interval between the optical fibers in a ribbon width direction.

Optical fiber unit and optical fiber unit manufacturing method

An optical fiber cable includes: a sheath; a core that is housed in the sheath and comprises optical fibers; tensile strength members embedded in the sheath; and ripcords embedded in the sheath. Recesses and protrusions are disposed alternately in a circumferential direction on an outer circumferential surface of the sheath. The recesses each include: two connecting portions respectively connected to radial inner ends of two adjacent protrusions; and a bottom surface positioned between the two connecting portions. In a transverse cross-sectional view, the ripcords are positioned inside some of the protrusions, and the tensile strength members are positioned inside the remaining protrusions.

An optical fiber cable includes: a cable body that includes an optical fiber; an external sheath that accommodates the cable body; a protective layer that is disposed between the cable body and the external sheath and that includes a first groove on an inner circumferential surface of the protective layer, wherein the first groove extends along an axial direction of the cable body; and a first ripcord disposed in the first groove and between the cable body and the protective layer.

An optical cable includes: twisted optical fiber units each including a fiber group formed by optical fibers. At least one of the optical fiber units includes a filling that wraps an outer circumference of the fiber group.

Optical cable and optical cable manufacturing method

An optical fiber protective unit includes: a reticulated tube; and a tubular member that is inserted through the reticulated tube and that is configured to accommodate a plurality of optical fibers. The reticulated tube is disposed on an outer periphery of the tubular member in a state folded in a longitudinal direction. Both end parts of the reticulated tube are located on the outer periphery of the tubular member.

Reticulated tube, optical fiber protective unit, method for protecting optical fiber, and method for manufacturing reticulated tube

A cable that protects an object includes: a sheath; and a cylindrical reinforcement member disposed inside the sheath and that surrounds the object. The cylindrical reinforcement member has a first side edge and a second side edge that extend in a longitudinal direction. The cylindrical reinforcement member is formed of a cable reinforcement sheet including: a first metal sheet; and a second metal sheet joined to the first metal sheet. A portion of the first metal sheet overlaps a portion of the second metal sheet, and the overlapping portions define a joint portion where the first metal sheet and the second metal sheet are joined. The joint portion is inclined, from the second side edge to the first side edge, toward the first metal sheet.

[Problem] When a surface of the optical fiber ribbon is rough, the microbending loss is increased due to the irregularities formed on the surface of the optical fiber ribbon. [Solution] An intermittently connected optical fiber ribbon of the present disclosure, includes: a plurality of optical fibers arranged in a predetermined direction; and connecting portions that intermittently connect two adjacent ones of the optical fibers. A peripheral cover portion formed of resin configuring the connecting portions is formed on a periphery of the optical fibers. An arithmetic mean roughness Ra of a surface of the peripheral cover portion is 0.41 μm or lower.

Provided is an optical fiber ribbon capable of achieving higher density and reduction in diameter and accurately placing optical fibers in V-shape grooves in a fusion machine without failure. The optical fiber ribbon 1 includes three or more of optical fibers 2 arranged in parallel and connecting portions 3 connecting adjacent two optical fibers 2 together, the connecting portions 3 being intermittently provided in each of a ribbon longitudinal direction and a ribbon width direction. The connecting portions 3 are each formed in such a manner as to fill resin into a gap S formed between adjacent two optical fibers 2, and both surfaces of the respective connecting portions 3 are each formed into a recess having a concave shape curved toward a center of the gap S to separate from lines 4,5 each connecting contact points of the optical fibers 2 when being placed on a horizontal surface.

Optical fiber ribbon and optical fiber cable housing optical fiber ribbon

An optical fiber cable production method includes: feeding a core including optical fibers; winding a reinforcing wrap around the core and forming an overlapping portion in which end portions of the reinforcing wrap overlap each other at a portion of the reinforcing wrap in a circumferential direction; and performing extrusion molding of a sheath on an outside of the reinforcing wrap. The overlapping portion extends in a longitudinal direction of the optical fibers. In the performing extrusion molding, a resin that forms the sheath is inserted into a portion of the overlapping portion.

An optical fiber cable includes: a sheath including recesses and protrusions that are alternately disposed in a circumferential direction on an outer circumferential surface of the sheath; a core that includes optical fibers and is accommodated in the sheath; and tensile strength members embedded in the sheath. The core is interposed between the tensile strength members in a transverse cross-sectional view. In the transverse cross-sectional view, the tensile strength members are embedded in portions of the sheath facing outward from the core in a first direction in which the two tensile strength members face each other in the transverse cross-sectional view.

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Sakura, Japan

Akira Namazue