Light shield curtain assembly for reciprocating optical scanning head

摘要

First and second rollers extend perpendicular to the direction of reciprocation of the scanning head and are disposed on opposite sides of the scanning head in said direction. First and second curtains are fixed at first ends to the first and second rollers respectively and at second ends to the scanning head. The curtains are rolled around the respective rollers. First and second pulleys are fixed for rotation with the first and second rollers. A tensioned wire is fixed at its opposite ends to the first and second pulleys and rolled around the first and second pulleys in directions opposite to directions in which the first and second curtains are rolled around the first and second rollers respectively. As the scanning head is moved thereby unrolling one of the curtains, the pulleys and wire rotate the other roller so as to roll the other curtain thereonto.