| 摘要 |
<P>PROBLEM TO BE SOLVED: To reduce minimally the number of detection sensors for performing phase adjustment caused by rotation unevenness of each image carrier, and to thereby simplify a device constitution and reduce cost, concerning an image forming apparatus for forming a plurality of images by using a plurality of image carriers corresponding to the plurality of images respectively and superposing the plurality of images, and drive devices for driving the image carriers. <P>SOLUTION: The image forming apparatus D and the drive devices 100a, 100b include a first detection sensor 170 constituted so as to detect first detection information of a rotation timing by a first cam part 131 provided on a part in a first peripheral direction α1 of a first rotation member 150, and also to detect second detection information of a rotation timing by a second cam part 141 provided on a part in a second peripheral direction α2 of a second rotation member 160. <P>COPYRIGHT: (C)2011,JPO&INPIT |
