| 摘要 |
PURPOSE:To improve the efficiency of fault analysis by detecting the abnormality of an output element itself and controlling a copying system in accordance with the detected output. CONSTITUTION:A main control device of a copying machine is constituted of a central processor 2 consisting of a storage part, a CPU part, etc., an output element driving part 3, an operation/display part 4, and a comparator 5. When a driving signal for an output element (a) is outputted from the central processor 2, a detected driving current voltage conversion signal Sa is inputted to the comparator 5 and compared with reference voltages set up as upper and lower limits and its output A is inputted to the central processor 2. At the check of its self-diagnosis function, whether an output element ON flag has been set up or not is checked, and when the flag has been set up, AND between the signals A1' and A2' is found out. When the result is '1' or '0', a normal flag or an abnormal flag is set up respectively. If said ON flag is not set up, a normal flag is set up at A1'=0 or an abnormal flag is set up at A1'=1. |
