| 摘要 |
PROBLEM TO BE SOLVED: To obtain a plastic optical fiber by drawing a preform at high speed without degrading the optical characteristics of the preform when drawing the preform. SOLUTION: A preform 18 is set in a drawing device 10. A heating furnace 20 is constituted of heating machines 21 to 24 whose temperatures can be controlled independently and an orifice 24 is provided between respective heating machines. The outer diameter PD(mm) of the preform 18, the height HL(mm)of the heating machine 21 and the distance OD(mm) between the outer peripheral surface 18b of the preform 18 and the heating surface 21b of the heating machine 21 are set so as to satisfy relations of (PD×0.1)≤HL≤(PD×1.5) and (PD×0.2)≤OD≤PD. Since temperature control at drawing can be performed easily, the plastic optical fiber whose outer diameter is uniform can be obtained. COPYRIGHT: (C)2005,JPO&NCIPI |
