| 摘要 |
PROBLEM TO BE SOLVED: To provide a method for controlling an optical fiber-drawing device having a prescribed constitution, especially capable of unnecessitating a manual control operation for preventing a system runway caused by the overheat of a preform at a final fiber-drawing stage by controlling a preform-lowering speed in response to a specific measured value. SOLUTION: This optical fiber-drawing device is provided with a fiber-drawing over 12 permitting to introduce a preform 11 at a controllable lowering speed thereinto, a coating die 15 for coating the drawn fiber 13 with a resin, a drying and polymerizing oven 17 for solidifying the coated resin, and a capstan 14 for controlling a drawing speed for the optical fiber 13. The control of the device is carried out by measuring the tension of the bare fiber at the exit of the drawing oven 12 in a production stage e.g. by a fiber vibration analysis method based on a Fourier analysis and subsequently controlling the lowering speed of the preform 11 in response to the measured value. The speed of the capstan 14 is preferably further controlled by the measurement of the diameter of the fiber 13, and the output of the capstan 14 is controlled in response to the speed. |
