PROCESS AND DEVICE FOR COATING GLASS FIBER FOR TRANSMITTING LIGHT

摘要

PURPOSE:To keep degree of setting of an ultraviolet ray setting resin at a fixed value and to obtain glass fiber with high productivity by providing an ultraviolet ray shielding pipe on the circumference around optical fiber and keeping the degree of the energy of ultraviolet rays exposed to the optical fiber at a fixed level by moving the shielding pipe. CONSTITUTION:Optical fiber 8 is drawn by melting a tip end of a preform 1 of the optical fiber in a heating furnace 5, and an ultraviolet ray setting resin 3 is coated on the optical fiber 8. The fiber is allowed to pass through a shielding pipe 9 for ultraviolet rays and a transparent quartz pipe 7 purged with inert gas both being installed in an ultraviolet ray lamp 6, where the fiber is irradiated with ultraviolet rays. The shielding pipe 9 is moved vertically depending on the change of drawing velocity and the change of the degree of transmission of the ultraviolet rays due to contamination of the quartz tube. Thus, the quantity of ultraviolet ray energy exposed to the optical fiber 8 is kept at a fixed value controlling thus the degree of setting of the ultraviolet ray setting resin to a fixed level. The degree of shielding is decided by treating the signal for the velocity detected by a winding bobbin 13 and the signal from an ultraviolet ray power meter 14 provided to the quartz tube 7 with an operator 10.