| 摘要 |
<P>PROBLEM TO BE SOLVED: To provide an image forming apparatus constituted so that soiling on the rear side of a transfer sheet can be surely prevented in the case of using a patch pattern, dispensing with the installation of a cleaning means for a secondary transfer apparatus, and also, so that an image density control using the patch pattern can be performed even when the sheets are continuously let through. <P>SOLUTION: Regarding the tandem type image forming apparatus 1 capable of forming the patch pattern to control the image density on an intermediate transfer body 11, in the case of continuously letting the transfer sheets through, a sheet-to-sheet distance between the transfer sheets is set equal to or exceeding the circumferential length by the amount of one rotation of the secondary transfer roller 23 for applying a secondary transfer bias, and the patch pattern forming position is located so as to appear ahead of the leading end of the succeeding transfer sheet after the one rotation of the secondary transfer roller 23, and provided that the frictional coefficient of the surface of the intermediate transfer body 11 is expressed by μ1 and the frictional coefficient of the surface of the secondary transfer roller 23 is expressed by μ2, a relation of μ1>μ2 is set. <P>COPYRIGHT: (C)2007,JPO&INPIT |
