| 摘要 |
PROBLEM TO BE SOLVED: To make the shape of an outer sheath of an optical fiber cable which is a constituent element of aerial multiple drop cables into a shape with which a cicada cannot lay eggs near a coated optical fiber or hardly lays eggs. SOLUTION: One coated optical fiber 1 at the center of the cable and two tension members 2 disposed at both sides of and in parallel to the fiber 1 are covered in bloc with the outer sheath 3 with a nearly rectangular cross section so that the fiber 1 and the members 2 are included in the same plane. Protruding lines 30 with a chevron shape are continuously provided in the longitudinal direction on the surface, parallel to the above plane, of the outer sheath 3 and just above and just below the fiber 1 at both edges of the opening part of notches 4 extended in the longitudinal direction in parallel with the coated optical fiber 1 on the surface. The protruding lines make the laying posture of a cicada unstable, and thereby the probability that the notches are pierced by an ovipositor is reduced.
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