| 摘要 |
<P>PROBLEM TO BE SOLVED: To provide an image forming apparatus for forming a plurality of images by use of a plurality of image carriers corresponding to the images and superposing the images and to provide a driving device for the image carriers, the image forming apparatus and driving device being configured such that detection sensors for aligning phases due to rotation variations of the image carriers are reduced to the smallest possible number, thereby simplifying the configurations of the apparatus and device and attain the cost reduction of them. <P>SOLUTION: The image forming apparatus D and driving devices 100a to 100c include single detection sensors 170 and 170'', which detect the first detection information t1 of a first-group photoreceptor 30a for black and the second detection information t2 of second-group photoreceptors 30b for color. <P>COPYRIGHT: (C)2011,JPO&INPIT |
