| 摘要 |
<P>PROBLEM TO BE SOLVED: To obtain stable images by simply and precisely grasping whether a transfer member is replaced in an image forming apparatus, having a transfer member such as an intermediate transfer member or a carrying transfer member. <P>SOLUTION: The toner patterns, formed at photoreceptor drums 21a to 24a, are transferred to recording media directly or indirectly by the transfer member 12. A concentration sensor 16 detects the surface state of the transfer member and outputs the detected signals. In a decision control part 45, there are set a first voltage value indicating the lower limit of level values of the detected signals and a second voltage value obtained by the relationship between the number of sheets used at the transfer member and the detected signals. The decision control part decides whether the transfer member has been replaced, on the basis of the detected signals and the first and second voltage values. <P>COPYRIGHT: (C)2005,JPO&NCIPI |
