| 摘要 |
<P>PROBLEM TO BE SOLVED: To reduce cost for developer due to needless exchange by determining an actual service life of the developer according to the state of deterioration of the developer when two component developer composed of toner and carrier is used. <P>SOLUTION: A control section calculates a toner replenishing amount which is necessary for replenishing according to a toner concentration supplied to a developing device detected by a toner concentration sensor 211, counts an accumulated number of prints regarding printed recording paper, accumulates information of an accumulated number of prints regarding an action of the developing device and information of toner replenishing amount for the toner replenishing device, controls so that the accumulated number of prints which indicates an exchange period for a developer is determined based on the information of the accumulated number of prints and the information of the toner replenishing amount, furthermore stores initial physical property information regarding a carrier that is accommodated in a toner container to a RAM, and controls so that the accumulated number of prints is corrected based on the number of prints at the end of the service life corresponding to the initial physical property information and the number of prints at the minimum service life corresponding to a reference value of the initial physical property information in the initial state. <P>COPYRIGHT: (C)2012,JPO&INPIT |
