| 摘要 |
PURPOSE:To facilitate the speedy investigation of the cause of a fault by a diagnosis and to perform abnormality recovery smoothly in a copying machine which uses plural DC motors as a driving source, by detecting the revolving speed of the respective motors and generating the warning of an abnormal state. CONSTITUTION:Rotation detecting circuits 21-23 receive outputs V0 of ''0'' from motor control circuits 13-15 when the motors maintains prescribed revolving speeds or outputs V0 of ''1'' when the revolving speeds increase or decrease. Outputs depending upon the revolving states of the motors are evaluated by a copy sequence control circuit 20, which display warning on a display device 24 when an abnormal state is found. Since none of the motors operates except during copying operation, the evaluation of the outputs of revolution detecting circuits 21-23 results in that the abnormal state is identified, so this detection is stopped when the copying operation is not performed and when the revolutions of the motors start or end. |
