Abstract: An optical fiber cable includes: a core including an optical fiber; a first protective layer covering the core; and a second protective layer covering the first protective layer. An outer circumferential surface of the first protective layer has: one or more integrated regions fixed to or in pressure contact with the second protective layer; and one or more non-integrated regions neither fixed to nor in pressure contact with the second protective layer.

Abstract: An optical fiber cable includes a core including an optical fiber, a restricting member longitudinally attached to and covering the core, a sheath covering the restricting member, and a ripcord disposed between the sheath and the core and between a first part of the restricting member and a second part of the restricting member.

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: 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: A conduit for laying a cable includes a suspension wire, one or more hangers held by the suspension wire and having an accommodation space that accommodates the cable, and a groove extending along an axial direction of the suspension wire. The groove has an opening connected to the accommodation space. The opening has a width smaller than a maximum width of an interior of the groove.

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, wherein connecting portions of the optical fiber ribbon 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 holding state where the holder is holding the optical fibers.

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 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 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 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 intermittently connected optical fiber ribbon includes optical fibers, disposed side by side in a width direction of the optical fibers, and connecting portions that each intermittently connect two adjacent ones of the optical fibers. A center-to-center distance between any of the two adjacent ones of the optical fibers is greater than a diameter of the individual optical fibers. A total volume shrinkage per meter per 1° C. of the connecting portions of a single one of the optical fibers is 0.00070 mm3/m·° C. or lower.

Abstract: A reticulated tube includes: a plurality of openings that are reticulately formed; peripheral parts that form the openings; and a branch part that is formed in a boundary of three or more openings. The branch part includes three or more peripheral parts extending from the branch part. The reticulated tube is configured to accommodate a plurality of optical fibers inserted through the reticulated tube. The peripheral parts are restricted by the branch part and are bendable.

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 intermittently connected optical fiber ribbon includes optical fibers, disposed side by side in a width direction of the optical fibers, and connecting portions that each intermittently connect two adjacent ones of the optical fibers. A center-to-center distance between any of the two adjacent ones of the optical fibers is greater than a diameter of the individual optical fibers. A total volume shrinkage per meter per 1° C. of the connecting portions of a single one of the optical fibers is 0.00070 mm3/m·° C. or lower.

Abstract: A method for manufacturing an optical fiber ribbon includes: forming a colored layer on to each of a plurality of optical fibers and forming an optical fiber ribbon by curing a connecting material applied to a surface of the colored layer of each of the optical fibers to form connection parts that connect adjacent ones of the optical fibers. Forming the colored layer further includes: applying a coloring agent to the optical fibers and curing the coloring agent such that uncured resin remains on the surface of the colored layer. Forming the optical fiber ribbon further includes: applying the connecting material to the surface with the uncured resin and curing the connecting material and the uncured resin on the surface of the colored layer.

Abstract: A reticulated tube includes: a plurality of openings that are reticulately formed; peripheral parts that form the openings; and a branch part that is formed in a boundary of three or more openings. The branch part includes three or more peripheral parts extending from the branch part. The reticulated tube is configured to accommodate a plurality of optical fibers inserted through the reticulated tube. The peripheral parts are restricted by the branch part and are bendable.

Abstract: A method for manufacturing an optical fiber ribbon includes: forming a colored layer on to each of a plurality of optical fibers and forming an optical fiber ribbon by curing a connecting material applied to a surface of the colored layer of each of the optical fibers to form connection parts that connect adjacent ones of the optical fibers. Forming the colored layer further includes: applying a coloring agent to the optical fibers and curing the coloring agent such that uncured resin remains on the surface of the colored layer. Forming the optical fiber ribbon further includes: applying the connecting material to the surface with the uncured resin and curing the connecting material and the uncured resin on the surface of the colored layer.

Abstract: An optical fiber unit includes: a plurality of optical fibers; and at least two binding materials that bind the plurality of optical fibers. The two binding materials are wound around the plurality of optical fibers in an SZ shape and adhered to each other at reversed portions of the SZ shape to form an adhesive part. The adhesive part extends along a longitudinal direction where the optical fiber unit extends, and 0.15?L/(P/2)?0.8 is satisfied where L is a length of the adhesive part in the longitudinal direction and P is a binding pitch of the two binding materials in the longitudinal direction.

Abstract: An optical fiber unit includes a plurality of optical fibers; and two binding materials that bind the optical fibers. The two binding materials are wound around the optical fibers in an SZ shape, and are adhered to each other at respective reversed portions that form an adhesive part. The adhesive part has a plurality of intersection points of center lines of the two binding materials.

Abstract: An optical fiber unit includes a plurality of optical fibers; and two binding materials that bind the optical fibers. The two binding materials are wound around the optical fibers in an SZ shape, and are adhered to each other at respective reversed portions that form an adhesive part. The adhesive part has a plurality of intersection points of center lines of the two binding materials.