FREQUENCY MODULATOR AND FREQUENCY MODULATING METHOD FOR GENERATING IMAGE CLOCK USED FOR TURNING ON AND OFF LASER BEAM SCANNING IMAGE BEARING MEMBER

摘要

PURPOSE: A frequency modulator and a frequency modulating method are provided to obtain high printing quality and simplify necessary work by compensating a plurality of laser beams according to a characteristic of an optical system. CONSTITUTION: A segmentalizing device divides a main scanning line on an image bearing member into a plurality of pixel unit segments. An auxiliary clock calculating device calculates an auxiliary clock period for the individual segment by using a reference clock period and a variable magnification coefficient corresponding to the individual segment. An image clock generating device(17) generates an image clock for every individual segment based on a predetermined initial period and the auxiliary clock period. A reference value storing device stores a reference value. A detecting device detects a difference between the reference value and an actual laser irradiation position. A compensating element compensates misalignment from the actual laser irradiation position according to a result of the detection.