METHOD AND DEVICE FOR MANUFACTURING OPTICAL SPACER

PURPOSE:To prevent the formation of a groove from being defect by extruding a core-part side material to the periphery of a tension member first and forming a primary coating, then extruding a peripheral-edge side material onto the core-part side material of the primary coating, and forming them in a specific shape by using a die. CONSTITUTION:A shunt passage 3a shunts a resin material which is extruded to a nipple 2 through a resin passage 3 to the core part side of a spacer. The resin which is sent in the resin passage 3 is separated by the shunt passage 3a and sent into the shunt passage 3a and the outside passage 3b formed between the die 1 and nipple 2. The resin which is separated by the shunt passage 3a is extruded to cover the periphery of the tension member which is supplied into a tension member supply path as the primary coating, and sent in toward a die entrance 1a as it is. Then, the resin which is shunt to the external passage 3b where it enters the die entrance 1a is extruded integrally onto the primary coating resin. Consequently, the cause of a defect in molding due to a difference in the flow of the resin is removed and the stable formation of the groove is enabled.