| 摘要 |
<P>PROBLEM TO BE SOLVED: To averagely restrain dot displacements in a main scanning direction over the entire main scanning area. <P>SOLUTION: The image forming apparatus comprises: a light source configured to generate a light beam that is emitted according to image data in synchronization with a writing clock; optical scanning means by which the optical beam is scanned in a main scanning direction on an image carrier by a plurality of reflecting faces of a rotary polygon mirror rotated and driven by a rotation drive source; a reflecting face identification part which identifies each reflecting face of the rotary polygon mirror; sub-scanning direction drive means which moves the image carrier and the light beam relative to each other in a sub-scanning direction orthogonal to the main scanning direction; a storage part which stores jitter information of the light beam measured at a plurality of positions in the main scanning direction on each reflecting face of the rotary polygon mirror; and a control part which refers to the jitter information read from the storage part, obtains a correction characteristic approximate in a straight line for dot displacements in a plurality of positions that occur according to the jitter on the respective faces of the rotary polygon mirror, and adjusts the frequency and phase of the writing clock. <P>COPYRIGHT: (C)2013,JPO&INPIT |
