| 摘要 |
<p>A drawing device (1) has a drawing furnace (11), a protective tube (21) and a resin curing section (31). Disposed between the drawing furnace (11) and the protective tube (21) is a buffer chamber (41), having a length (L1) as seen in the drawing direction of optical fibers (3). The buffer chamber (41) is composed of a first buffer chamber (42) and a second buffer chamber (45). The inner space of the buffer chamber (41) contains a mixture of He gas which is the atmosphere gas in the drawing furnace (11) and air which is the atmosphere gas in the protective tube (21). The optical fibers (3) heated and drawn in the drawing furnace (11) are fed into the protective tube (21) and their predetermined regions are slowly cooled at a predetermined cooling rate. Thereafter, a UV resin liquid (63) is applied to the optical fibers (3) by a coating die (62), the UV resin (63) being cured in the resin curing section (31); the optical fibers become an optical fiber strand (4).</p> |
