PURPOSE: To make the monitoring of a copying machine easy, by changing over a display from a number display to a fault display so as to make the display different from the display in an abnormal state when the fault arises in a control circuit for an optical system.
CONSTITUTION: A gate 2 which controls the output of a counting means 1 for the number of copying sheets, a control gate 3 for a jamming output, a gate 4 which outputs the counting signal or jamming signal, a decoder 5 which converts the output thereof to the conduction signal of the segment of a display 11, an FF6 which outputs the binary signal indicating the jammed part, a detector 7 for the jammed part, an encoder 8 which converts the detection signal thereof to a binary encoded deicmal output, an FF9 which outputs the jamming signal, and a display 11 which can display the fault point are provided. Numbers are beforehand given to ≥1 piece of the detectors 7, and the numbers thereof are converted to binary values by the encoder 8, the output whereof is inputted to ≥1 piece of the FF group 6 corresponding to the weight of the binary number.
HONMA TOSHIO
SAKAMAKI HISASHI
