| 摘要 |
PURPOSE:To obtain the optical fiber having an excellent image transmission characteristic by disposing island parts each having an approximately circular shape and a specific diameter in piling structures of a specific number of pieces in a sea part in the relation of 1:1 to both end faces and providing a protective layer to prevent the infiltration of external light. CONSTITUTION:The sectional shape of the islands is approximately circular and the number of the island shaving 2 to 70 mum diameter is specified to a 50 to 20000 range. Maintaining of the uniformity is difficult if the number of the islands is too much. If the number of the islands is <50, the number of the picture elements in one piece of the fiber is too little and, therefore, the execution of the image transmission with the good resolution is difficult. Further, the fibers 13 of the peripheral part like the central part maintain high optical performance as the protective layer 12 consisting of the colored polymer coated integrally on the fiber at the time of spinning is formed. The arranging state of the islands disposed within the sea section is made into the piling structures or four-way stacking structures. The plastic multifilament type optical fiber having the excellent image transmission characteristic is obtd. if the fiber is formed in such a manner. |
