LIGHT BEAM SCANNER AND ITS CORRECTING METHOD

摘要

PROBLEM TO BE SOLVED: To prevent the mutual positions of plural light beams from being fluctuated due to the temperature change or the secular change of an optical system located before a scanning optical system in a light beam scanner synthesizing all the light beams after at least the partial light beam of the plural light beams is deflected by a light deflecting element and performing scanning by the common scanning optical system and to prevent the deterioration in the image quality of the above optical system caused by the non-uniformity of optical power in the diameter of a light beam and the astigmatism of the optical system. SOLUTION: The positions of plural light beams are detected by a beam position detecting element 14 and a beam position correction data for the light deflecting elements AODa to AODc for keeping the relative positions of each of the light beams detected by the element 14 constant is stored. Meanwhile, the relative positional deviation of the recording positions is detected from the recording positions of each of the light beams recorded on a light beam exposure surface, and additional correction data for correcting each of the positional deviation of the recording positions is added to the beam position correction data so as to obtain final correction data for driving the elements AODa to AODc.