Method of and apparatus for jitter correction of a polygon mirror in an

Abstract

A clock generator (15) and a delay circuit (16) create N dot recording clock signals (.phi..sub.1 to .phi..sub.N) of a cycle t, delayed by t/N. A counter (20) counts a detecting time interval between a start sensor (12) and an end sensor (14) for every surface of a polygon mirror (8) to generate time resolution t/N. The difference between the count value and a reference count value set in a latch (24) is input to a subtracter (23), so that a translation table (28) outputs clock crossover timing responsive to the difference. A latch (17) and an encoder (18) select an N dot recording clock signal synchronous with detection output of the start sensor (12) for every surface of the polygon mirror (8). A second selector (33) outputs a crossover dot recording clock signal (.phi..sub.X) for image recording by performing crossover from the selected dot recording clock signal to other dot recording clock signals that are sequentially along the clock crossover timing.