| 摘要 |
<p>In a heating furnace (1), an optical fiber preform (2) is heated and the optical fiber (3) is drawn. The obtained optical fiber (3) is cooled by a cooling gas in a cooling apparatus (4) provided beneath the heating furnace (1), then a resin is coated on the outer circumference of this optical fiber (3) by a resin coater (6). At this time, the blowing direction of the cooling gas blown out from the optical fiber inlet (19) of the cooling apparatus (4) is inclined exactly by a predetermined angle ( theta ) with respect to the axial line of the running optical fiber (3). As a result, even if no rise suppression gas is used, it is possible to prevent the cooling gas blown upward from the cooling apparatus (4) from entering into the heating furnace (1) and thereby to prevent the lowering of the quality of the optical fiber (3) due to the adhesion of dust. Also, a cooling apparatus container enclosing the cooling apparatus (4) is provided. The cooling of the optical fiber (3) is carried out by the cooling gas while holding the inside of this cooling apparatus container at a positive pressure with respect to the outside environment by a positive pressure forming gas from which dust has been removed. As a result, the rise of the manufacturing cost of the optical fiber production apparatus can be prevented. <IMAGE></p> |
