| 摘要 |
<p><P>PROBLEM TO BE SOLVED: To prevent a sub-scanning shift of an amount of one plane of a polygon mirror at the time of imaging processing while a phase of each index signal is prevented from skipping that of a reference index signal even when the index signal of each color causes a drift variation following a temperature change. <P>SOLUTION: This image forming apparatus is equipped with an image forming part 80 which carries out imaging processing by rotating the polygon mirror 34 on the basis of a reference-IDX signal and scanning a laser beam light to a photoreceptor drum 1Y or the like, a phase difference detecting part which detects a phase difference between a YMCK-IDX signal obtained by detecting the laser beam light scanned by the image forming part 80 to the photoreceptor drum 1Y or the like and the reference-IDX signal, and a controlling part 15 which interrupts imaging processing on the basis of the result of comparison between the phase difference detected by the phase difference detecting part and a threshold for judgement on the phase difference, and then carries out polygon phase control of matching the phase difference with a predetermined target phase difference. <P>COPYRIGHT: (C)2008,JPO&INPIT</p> |
