| 摘要 |
<P>PROBLEM TO BE SOLVED: To provide an image forming apparatus capable of accurately determining that a replaced process unit is new one. <P>SOLUTION: A process unit having a developing unit using a two-component developer containing a toner and a carrier is replaceable with respect to an apparatus body, and an output of a toner concentration sensor provided on the developing unit is written into a body memory right before the process unit is replaced. When the process unit is replaced, an output of the toner concentration sensor is compared with the output of the toner concentration sensor written into the body memory at that time. If there is a predetermined difference between the outputs, the replaced process unit is determined as new one. <P>COPYRIGHT: (C)2013,JPO&INPIT |
