Automatic control system for offset printing machine

Abstract

An automatic control system for an offset printing machine includes a process execution instructions generating circuit having latched therein instructions for executing various operation processes and adapted to shift from one operation phase to another for successively generating process execution instructions, so that an ink forming and master plate feeding process, an inking process, a transfer-printing process, a printing process, and a master plate ejecting and cleaning process can be automatically executed in correct order. The number of times for executing each of the etching, inking, transfer-printing and cleaning processes can be adjusted in a process setting structure. When a master plate feeding error detecting signal is generated, the process execution instructions generating circuit is reset to an initial condition of stop instructions which prevailed prior to actuation of a start switch. When a master plate ejection error signal or other misoperation indicating signal is generated, the process execution instructions generating circuit remains latched to the current operation process, and a lamp is lighted to indicate the process in which misoperation has occurred. The period of time for moistening an etching roller can be determined depending on the number of copies to be produced. The control system allows the offset printing machine to manually execute any operation process or processes as desired.