| 摘要 |
PROBLEM TO BE SOLVED: To surely discriminate whether a process cartridge is attached or not. SOLUTION: After T2 hours passes from the start (108) of voltage application to a transfer roll, an output current I from the transfer roll is measured (112), and measurement is repeated at every T3 hours thereafter. Then, based on whether the average value IA of the output current I obtained by the measurement of total (n) times is larger than a specified threshold value I0 or not, a device discriminates whether the process cartridge is attached or not (122). In the case that the average value IA is smaller than the threshold value 15, applied voltage to the transfer roll is stepwise increased (126) within the range of not exceeding previously decided maximum voltage (124) the measurement of the output current I (112) and discrimination are performed each time (122). Then, when the average value 13 is confirmed to be larger than the threshold value IO, the device discriminates as the process cartridge is attached (130). |
