| 摘要 |
<P>PROBLEM TO BE SOLVED: To provide an image forming apparatus in which a large shift in a vertical scanning direction is prevented from abruptly being made even when registration correction is performed. <P>SOLUTION: The image forming apparatus of the present invention has a phase difference setting section which sets phase differences from reference phases of rotation of polygon mirrors of a plurality of image formation sections by the image formation sections based upon a sub-scan registration quantity, a 1st phase difference re-setting section which re-sets a phase difference to outside a setting inhibition region when the phase difference set by the phase difference section is within the setting inhibition region, a phase control section which performs phase matching control based upon the set phase difference before the start of image formation, and a 2nd phase difference re-setting section when re-sets the phase difference of a polygon mirror to outside the setting inhibition region and makes the phase control section perform phase matching control again when the phase difference from the reference phase is within a presence inhibition region narrower than the setting inhibition region after the phase matching control by the phase control section. <P>COPYRIGHT: (C)2006,JPO&NCIPI |
