METHOD AND APPARATUS FOR PRODUCING PLASTIC OPTICAL FIBER, AND METHOD AND APPARATUS FOR COATING THE SAME

摘要

A raw POF is drawn by first and second roller pairs being as a drawing device while continuously advanced and heated by a heater. A heating length of the heater is set to a range of 0.1 to 1 m, and a magnification for drawing is set to 1.5 to 3.5 times in a longitudinal direction. Rollers of the first and second roller pairs are independently driven to individually control rotating speeds thereof. The obtained POF is excellent in mechanical strength and has a uniform outside diameter. Further, the obtained POF is excellent in optical transmission properties and workability. When a clad of the POF has an outside diameter D1 and a core thereof has an outside diameter D2, a relation of D1 = D2 x 1.5 is satisfied. At a time of coating, a percentage of length change is set so as to be 1% or less.