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 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 arrangement method includes: preparing an intermittently connected optical fiber ribbon including optical fibers arranged side by side at a first pitch larger than a fiber diameter; holding a non-connecting region of the optical fiber ribbon with a holder, where connecting portions intermittently connect the optical fibers extending out from the holder to each other; changing a width of the optical fiber ribbon in an interior of the holder; and arranging the optical fibers, extending out from the holder, with intervals of the optical fibers changed from the first pitch to a second pitch smaller than the first pitch by removing the connecting portions in a state where the holder is holding the optical fibers.

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 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 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: An optical cable includes an optical fiber, an outer sheath that houses the optical fiber, and a tubular reinforcement sheet disposed between the optical fiber and the outer sheath. In a cross section perpendicular to a length direction of the optical cable, an adhesive strength between the tubular reinforcement sheet and the outer sheath in a first zone is stronger than an adhesive strength between the tubular reinforcement sheet and the outer sheath in a second zone.

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: [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: 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: A housing unit includes: a linear material; and a housing body that houses the linear material. In the housing body, winding regions in which the linear material is wound are disposed in a circumferential direction. The linear material is wound in a figure eight in a first region pair constituted by a pair of the winding regions. The linear material is wound in a figure eight in a second region pair constituted by a pair of the winding regions that are different from the winding regions constituting the first region pair.

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.

Abstract: An optical cable wiring method, includes: installing a bundle of optical cables from a utility pole as a starting point of a first wiring path to a branch point on the first wiring path; dividing, at the branch point, the bundle of optical cables into a first group and a second group; installing one of the optical cables in the first group along the first wiring path ahead of the branch point; and installing one of the optical cables in the second group along a second wiring path branching from the first wiring path.

Abstract: A management device that manages a unit including a drum and a long object wound around the drum, the management device includes: a receiver that receives, from a user terminal, a captured image obtained by capturing an image of the unit; and a controller that accesses correspondence data obtained by associating each of image capture results, obtained by successively capturing images of the unit while winding the long object around the drum, with a corresponding winding amount of the long object wound around the drum at a time when the each of the image capture results was obtained. The controller determines a remaining amount of the long object based on the captured image and the correspondence data.

Abstract: An optical fiber cable includes: a sheath; and a core including twisted optical fibers disposed in an accommodation space in the sheath. Each of the twisted optical fibers includes: a glass portion, a primary layer that covers the glass portion, and a secondary layer that covers the primary layer. A fiber pulling force when pulling out the twisted optical fibers is equal to or greater 15 N/10 m. A value of an index Q is less than 20.

Abstract: 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.