| 摘要 |
<P>PROBLEM TO BE SOLVED: To improve handleability of an image forming apparatus by always preventing misregistration. <P>SOLUTION: A mark for detecting misregistration is a segment of a horizontal or oblique line. A mark group is constituted of a plurality of marks. The mark groups are arranged by a plurality of rows and a plurality of columns, thereby obtaining a pattern set of patterns for correcting misregistration. A plurality of sets of patterns for correcting misregistration are formed on an endless belt. The position of the mark is detected for each pattern set by sensors 17, 18 and 19 and position information is stored. The detection number of the position of the mark is counted for each mark group to examine whether or not an abnormal mark group whose detection number of the position of the mark shows other than a specified number exists. A misregistration amount is calculated for each pattern set excepting the position information of the abnormal mark group. Alternatively, the misregistration amount is calculated excepting the position information of the abnormal mark group from all the pattern sets. <P>COPYRIGHT: (C)2009,JPO&INPIT |
