Abstract: In order to avoid a frequent multiple crossing in an optical fiber in a sheet and attach the optical connector near a marginal end of the sheet while maintaining a sufficient extra length and more extra length for attaching the optical fibers, in the optical fiber sheet 6, an optical fiber 5 as an extra length section in the optical fiber path is disposed on three-layer wiring planes which are formed by attaching four sheets 1, 2, 3, and 4. Notched sections 2a and 3a are formed in the intermediate layers 2 and 3. The optical fiber 5 communicates from a first wiring layer to a second wiring layer via the notched section 2a so as to communicate from the second wiring layer to a third wiring layer via the notched section 3a.

Abstract: A thermoplastic resin coated optical fiber having an outer diameter of 0.9 mm is formed by providing a coating layer around a reinforcing resin coated optical fiber having an outer diameter of 0.25 mm, and has a flexural rigidity of 5.5 to 7.5 N·mm2. The coating layer comprises a thermoplastic resin having a bending elastic modulus of 200 to 350 MPa and the thermoplastic resin is a polyester elastomer. When optical fiber cords are connected to each other or when an optical fiber is exposed to low temperatures, loss is prevented from increasing and superior transmission characteristics are exhibited.

Abstract: A thermoplastic resin coated optical fiber having an outer diameter of 0.9 mm is formed by providing a coating layer around a reinforcing resin coated optical fiber having an outer diameter of 0.25 mm, and has a flexural rigidity of 5.5 to 7.5 N·mm2. The coating layer comprises a thermoplastic resin having a bending elastic modulus of 200 to 350 MPa and the thermoplastic resin is a polyester elastomer. When optical fiber cords are connected to each other or when an optical fiber is exposed to low temperatures, loss is prevented from increasing and superior transmission characteristics are exhibited.