Abstract: An optical cable includes optical fiber units each including a bundle of optical fibers. The optical fiber units are twisted together in an S-Z configuration in which a twisting direction of the optical fiber units is reversed at a reversal part and an adjacent reversal part adjacent to the reversal part. A twisting angle, by which the optical fiber units are twisted in a circumferential direction between the reversal part and the adjacent reversal part, is 540 degrees or greater.

Abstract: 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.

Abstract: An optical fiber cable includes optical fibers, a wrapping tube that wraps around the optical fibers and contacts outermost ones of the optical fibers, and a sheath that covers the wrapping tube and has recesses on an inner circumferential surface of the sheath. The recesses are recessed toward a radially outer side of the optical fiber cable such that a space exists between the wrapping tube and the sheath in each of the recesses.

Abstract: 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 ?m or lower. A ten-point mean roughness Rz of a surface of the peripheral resin portion is 1.4 ?m or lower.

Abstract: A fixing structure includes: an optical fiber group constituted by a plurality of optical fibers; a tubular member through which the optical fiber group is passed; a reticulated tube, one end part of the reticulated tube being disposed on an outer periphery of the tubular member, the optical fiber group being inserted through an extended section of the reticulated tube extending out from the tubular member; and a fixing member that fixes the tubular member which has the reticulated tube disposed on the outer periphery thereof.

Abstract: 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.

Abstract: 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.

Abstract: 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.

Abstract: 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 ?m or lower. A ten-point mean roughness Rz of a surface of the peripheral resin portion is 1.4 ?m or lower.

Abstract: 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.

Abstract: 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.

Abstract: 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.

Abstract: [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 ?m or lower.

Abstract: 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.

Abstract: 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.

Abstract: 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.

Abstract: 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.

Abstract: 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.

Abstract: An optical fiber cable includes: a sheath; and a core that is housed in the sheath and includes optical fibers. Recesses and protrusions are disposed alternately in a circumferential direction on an outer circumferential surface of the sheath. The optical fiber cable has a compressive strength of 12.8 N/mm2 or greater and 32.4 N/mm2 or less.

Abstract: 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.