Synchronizing apparatus of a cascade scanning optical system having tilting measurement of reflecting surfaces

Abstract

A cascade scanning optical system which includes: a first laser scanning optical system having a first polygon mirror, provided with a plurality of first reflecting surfaces, for deflecting a first scanning laser beam to scan a part of a scanning surface to generate a first scanning line; a second laser scanning optical system having a second polygon mirror, provided with a plurality of second reflecting surfaces, for deflecting a second scanning laser beam to scan another part of the scanning surface to generate a second scanning line, wherein the first and second laser scanning optical systems are arranged so as to align the first scanning line with the second scanning line at a point of contact therebetween in a main scanning direction to form a single scanning line; means for measuring a degree of tilt of each of the plurality of first reflecting surfaces and the plurality of second reflecting surfaces; and means for determining combinations of the plurality of first reflecting surfaces with the plurality of second reflecting surfaces in accordance with results of measurements of the measuring means so that the single scanning line is formed by any one of the combinations while minimizing a phase difference between a first phase formed by degrees of tilt of the plurality of first reflecting surfaces and a second phase formed by degrees of tilt of the plurality of the second reflecting surfaces.

Dependencies are inferred from the claim text.