| 摘要 |
PURPOSE:To prevent action of copying means due to an erroneous signal, by resetting a microcomputer at start in a microcomputer-controlled electrophotographic copying machine, and then, making the copying means operable. CONSTITUTION:Upon turning on a switch, voltage is applied to the input terminals of comparators Q108-1, Q108-2 with resistors RA133-2, RA131-4. At that time, voltage is applied to the comparator Q108-1 through a resistor RA133-3 in a delayed form of rise time with a time constant circuit consisting of a resistor RA133-1. During about 30msec affter the supply of power, voltage of a negative side terminal is higher than that of the positive side terminal, and OV is fed from the output terminal of the comparator Q108-1, serving as a reset signal for a microcomputer. In addition, a diode D119 serves as a discharge diode on opening of the power supply, and a resistor RA134-2 gives hysteresis for preventing an erroneous action and chattering. |
