Patent ID: 7234881
Filing Date: 2007-06-26
Classification: B29C,B29L,G02B

Abstract:
1. A method for molding a reinforcement resin coating of a glass optical fiber exposing portion of an optical fiber junction comprising the steps of: using a molding die constituted by upper and lower dies at least one of which is made of a material transparent to an ultraviolet light, said molding die having a cavity constituted by grooves of said upper and lower dies linearly penetrating therethrough along respective parting faces thereof, each groove having a semicircular lateral cross section, said molding die having a resin injection gate and a resin exit gate communicating with said cavity, said resin injection gate is not positioned at a center of said cavity in a longitudinal direction thereof; inserting fusion-spliced optical fibers including said glass optical fiber exposing portion in which end faces of glass optical fibers exposed by removing a coating at end parts of two optical fibers are butted against each other and said exposed end parts are fusion-spliced into said cavity of said molding die; positioning one coating end of said fusion-spliced optical fibers near said resin injection gate so that a fusion-spliced point of said fusion-spliced optical fibers is not opposed to said resin injection gate; positioning the other coating end of said fusion-spliced optical fibers near said resin exit gate so that said fusion-spliced point of said fusion-spliced optical fibers is not opposed to said resin exit gate; injecting a UV-curable resin into a void surrounding said glass optical fibers within said cavity from said resin injection gate; and then emitting said ultraviolet light through said die made of said UV-curable resin from the outside of said molding die, so as to cure said UV-curable resin injected into said cavity and form a reinforcement resin coating, wherein said parting face of said upper and lower level dies are provided with an UV-light-blocking layer extending along a part of said parting face including a position in contact with said groove in a segment including said resin injection gate and said resin exit gate, said UV-light-blocking layer is not formed on said grooves.