PURPOSE: To prevent trouble caused by a defect in a driving device and simultaneously, to shorten time up to a start possible state by rotating a DC motor and calculating the load torque of each driving device.
CONSTITUTION: When a main switch is turned on, the DC motor 1 is rotated to measure a current value and the load torque imparted to the output shaft of the DC motor 1 is calculated from the measured current value. The load torque is the total of the idling loads of timing belts 29 and 30, a gear, a photosensitive body, etc. At this time, the load torque is compared with the stored set value and in a value so as to seriously affect a device, the DC motor 1 is stopped to attain processing in abnormality. In normality, first, a developing clutch 17 is turned on to calculate and compare the load torque similarly and in the value so as to seriously affect the device, the DC motor 1 is stopped to attain the processing in the abnormality. The processing is repeated in order of each clutch, the checking of all clutches is completed and then, the DC motor 1 is stopped to obtain a copying standby state.
KOBAYASHI AKINORI
KOBAYASHI KAZUHIKO
