Patent ID: 7458234
Filing Date: 2008-12-02
Classification: C03B

Abstract:
1. An elongating method of an optical fiber base material, wherein, in an elongating process of elongating an optical fiber base material by heating the optical fiber base material in a heating furnace such that a diameter of the optical fiber base material is reduced, before the optical fiber base material having a distorted portion is elongated from an end thereof, the distorted portion of the optical fiber base material is corrected by being heated to be softened in the heating furnace such that the distorted portion is corrected by its own weight, wherein the elongation is started after the optical fiber base material is attached to a hanging mechanism such that said optical fiber base material is hung in the heating furnace, after the distorted portion of the optical fiber base material is heated to be softened, and after a difference between an elongation axis and an end of one of the optical fiber base material and a dummy rod attached to the optical fiber base material is reduced and judged to be 10 mm or less.