Mitsubishi Rayon Company, Limited

Yoshiro Nieda

Kenichi Sakunaga

Naoyuki Fukahori

Masashi Okamoto

Hiromu Terada

Yoshihiko Hoshide

A sheet-shaped photoconductor composed of a plurality of optical fibers is prepared by melt-spinning a spinning dope into optical fibers and, before the as-spun fibers are completely solidified, bonding the fibers to one another along the entire length thereof. The melt-spinning is carried out using a nozzle having a plurality of annularly arranged orifices. The as-spun fibers are arranged linearly in parallel to but not in contact with one another by using a grooved guide, and then the optical fibers are brought into contact with and fusion-bonded to one another by using a fusion bonding guide having a concave curved face in the central portion thereof, and the thus-formed sheet-shaped photoconductor is taken up.

Apparatus for preparation of a sheet-shaped photoconductor

A multifilament type plastic optical fiber having a substantially uniform cross-section and an islands-in-sea structure, in which 10 to 10,000 islands are arranged in the sea, the respective islands have a substantially uniform cross-section having a diameter of 10 to 200.mu. and the sea occupancy ratio in the cross-section of the optical fiber is 5 to 40%, said optical fiber being prepared by constructing a true conjugate spinning spinneret by (a) an orifice plate having 10 to 10,000 core-forming holes, (b) an orifice plate having 10 to 10,000 sheath-forming holes and (c) an orifice plate having 10 to 10,000 sea-forming holes having an opening expanded downward, the lower ends of every two adjacent sea-forming holes having contacted with each other on the lower end face of said orifice plate, so that a fiber comprising the sea and islands having a core-sheath structure is formed by true conjugate spinning without using a filament-gathering orifice plate, supplying a core-forming polymer, a sheath-forming polymer and a sea-forming polymer to respective spinning holes, melt-spinning the polymers under such conditions that the spinning draft D defined by the following formula [I]:

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Otake, Japan

Yoshiro Nieda