Correcting method of light beam position in a scanning apparatus

摘要

A method for correcting recording positions of light beams scanned by a light beam scanning apparatus, in which at least one of plural light beams is deflected by an optical deflecting device and all the plural light beams are combined and scanned by a common scanning optical system. The beam position correction data for the optical deflecting device for keeping positions of the light beams constant is obtained by detecting the beam positions before the scanning optical system. The recording positions of respective light beams on a recording surface is also detected to obtain an additional correction data for correcting deviations of the recording positions due to uneven optical power distribution of the light beam or astigmatism of the scanning optical system. The additional correction data is added to the beam position correction data to obtain the final correction data, by which the optical deflecting device is controlled.