PURPOSE: To uniformly coat an optical fiber with a resin without forming unevenness in a coating film and not to make a flaw caused by contact of the optical fiber with a nipple, etc.
CONSTITUTION: An optical fiber A is inserted into a coating die 21 which is provided with a nipple 22 having a tapered insertion hole 26 with a diameter reducing from an inlet 24 toward an outlet 25 and with a die 23 arranged below the nipple 22 having a tapered insertion hole 29 with a diameter reducing from an inlet 27 toward an outlet 28. When a resin solution B is fed to a gap between the nipple 22 and the die 23 and the optical fiber is coated with the resin solution B, the optical fiber is inserted in a state of the resin solution B stored also at the upper side of the outlet 25 of the insertion hole 26 of the nipple 22.
HAGINO NAOKI
TAKAHASHI KOICHI
