| 摘要 |
<p>PROBLEM TO BE SOLVED: To produce a glass base material in a high product yield.SOLUTION: A method of drawing a glass base material includes a formation step of forming a taper part in which the outer diameter of the glass base material changes in the longitudinal direction of the glass base material, a holding step of holding the glass base material with a chuck, a heating step of heating a heating region, a longitudinal-direction part, of the glass base material held with the chuck, with a heating source, and a drawing step of expanding the interval of the chuck in the longitudinal direction of the glass base material in a state where a part of the glass base material is softened by the heating with a heat source. The drawing step is started from a state where the position of the heating source at the center of the heating region is located at the drawing starting position set in the range in the taper part with the outer diameter of the glass base material being equal to or greater than 95% and equal to or smaller than 98% of the average outer diameter of the straight cylindrical body part.</p> |
