LARGE-DIAMETER HEAT RESISTANT PLASTIC OPTICAL FIBER FOR ILLUMINATION

摘要

PROBLEM TO BE SOLVED: To provide a large-diameter heat resistant plastic optical fiber for illumination with which the moisture permeation to a core is prevented even at and under a high temp. and high humidity and a stable light quantity is maintained. SOLUTION: A water absorptive layer 3 is formed by longitudinally attaching or transversely winding a water absorptive tape 3a formed by holding a water absorptive material with two non-woven fabrics on the outer periphery of a heat resistant plastic optical fiber 10. As a result, even if the moisture permeates a resin layer 4, this moisture is absorbed by the water absorptive layer 3 and the permeation of the moisture to the fiber 10 is prevented. The fiber wound with the tape is coated thereon with the soft resin layer 4, by which the floating of the tape is held down by the resin layer 4 and the generation of a spacing is prevented even if the floating of the tape occurs when the fiber 10 is bent and, therefore, the bending characteristic is improved.