| 摘要 |
PURPOSE:To surely discriminate that a unit attains a set lifetime and to prevent the unit from being used in the excess of the set lifetime by controlling the quality of an image so that it may be deteriorated in the case that the cumulative value of the counted number of image forming times gets a specified value. CONSTITUTION:The cumulative value of the number of image forming times is obtained by a counter in the ROMB 402c of a control circuit 402. When the cumulative value gets the specified value, the circuit 402 controls to deteriorate the image quality by judging that the exchange time of the process unit or a fixing unit elapses. For example, in processing for the case that the lifetime of a photosensitive drum is expired, a state where the image quality is deteriorated is artificially made according to the change of the process condition of a developing bias potential and an electrostatic charging potential. At the time of completing the processing for deteriorating the image quality, the control temperature of the fixing unit is raised and a mirror motor and a main motor are rotated. Furthermore, a paper supply solenoid is turned on/off and the image data is transferred simultaneously with the transfer of a paper, thereby surely discriminating that the unit attains the specified lifetime. |
