CIRCUIT TO INHIBIT MAIN LOGIC DURING REDUCTION MODE CHANGE
Original Publication Date: 1978-Dec-31
Included in the Prior Art Database: 2004-Mar-31
Xerox Disclosure Journal
When changing image magnification in a copying machine, it is necessary to disable the machine control logic 15 during the changeover. This objective is accomplished by sensing both the lens forward and lens reverse drive latches 10, 11 through an OR gate 12. The output of gate 12 is connected through an open collector inverter 14 to produce a signal (INHIBIT) inhibiting operation of the main machine logic 15. Thus, whenever either the lens forward latch 10 or the lens reverse latch 11 is set, the main control logic 15 is held in its initial state preventing machine operation until the change is complete.