| 摘要 |
<P>PROBLEM TO BE SOLVED: To provide a speed change detection apparatus which is capable of detecting the high-frequency speed change of a photoreceptor, even when a high-resolution detection means is not used and is without useless toner consumption. <P>SOLUTION: A predetermined periodical latent image pattern is formed on a photoreceptor drum 1 as a latent image carrier. When the period of a latent image pattern is closer to the period of a speed change, a moire appears in the period longer than the original speed change period. The moire is detected by using an alternating current conversion type surface potential sensor 6, so that the high-frequency (=short period) speed change can be detected even by a surface potential sensor having a low resolution. <P>COPYRIGHT: (C)2009,JPO&INPIT |
