| 摘要 |
<P>PROBLEM TO BE SOLVED: To provide an image forming apparatus which can detect paper feed timing with high precision, can eliminate a deterioration in image position precision due to mounting errors and durability of components, and can always precisely adjust the image position. <P>SOLUTION: A frame image 210 with 5-mm wide margins is formed on a paper sheet on the basis of the leading end and widthwise end positions of the paper sheet 107 detected by a contact image sensor (CIS) 204 in an adjustment mode. After that, this paper sheet 107 is circulated to a feed position via a circulating path 206 and paper convey path 205, and the CIS 204 detects the frame image position formed on the circulated paper sheet and its paper end portion so as to detect errors with respect to the 5-mm wide margins. Correction values which can cancel these errors are stored in a correction parameter storage unit 71, and forming start timing control is made using these correction values upon forming an image in an actual job. <P>COPYRIGHT: (C)2004,JPO |
