1. Field of the Invention
The present invention relates to a fiber optic connector ferrule for arranging optical fibers, and a method of making the same.
2. Related Background Art
In general, when optical fiber ribbons are to be connected to each other, the coating is removed from an end portion of optical fiber ribbons so as to expose each optical fiber, and a fiber optic connector ferrule made of a synthetic resin for arranging the optical fibers is attached to this end portion, thereby establishing the connection. The connector ferrule is used for accurately arranging the optical fibers. FIG. 11 shows the configuration of a typical fiber optic connector ferrule manufactured to JIS C 5981.
The fiber optic connector ferrule 102 shown in FIG. 11 has a plurality of parallel fiber-arranging holes 120 for arranging the respective optical fibers therewithin. Disposed on the inside or the fiber insertion side of each fiber-arranging hole 120 is a tapered portion 121 whose inside diameter gradually increases so as to continue to a groove portion 122. The connector ferrule 102 also has an open portion 123 used for receiving an adhesive for securing an optical fiber ribbon 103 (see FIGS. 13 and 14), a pin hole 124 into which a guide pin is inserted at the time of connecting with the other fiber optic connector ferrule to be paired.
While the connector ferrule 102 is being molded by transfer molding or injection molding, each fiber-arranging hole 120 is formed by an axially-slidable mold pin 101 (see FIG. 12) disposed within a mold (not shown) adapted to open vertically. For easier understanding of the structure, only two mold pins 101 are shown in FIG. 12. Each mold pin 101 is a round pin having a circular cross section, and is constituted by a first columnar portion 101a, a second columnar portion 101c having an outside diameter greater than that of the first columnar portion 101a, and a tapered portion 101b connecting the first and second columnar portions 110a, 101c, all of which are concentric. The mold pins 101 are held by holding members 113 on the proximal end side thereof. At this time, a plurality of mold pins 101 are accurately positioned by V-shaped grooves 114 of one of the holding members 113.