AUTOMATED PRINTING PRESS WITH REINSERTION REGISTRATION CONTROL

摘要

An automated printing press (10) is provided with a plurality of printing stations (13), each having a printing mechanism (60) which prints at least one component image at spaced apart locations along a web (11). Each printing mechanism (60) is also positionable to one side of the press to facilitate its servicing. Computers (400, 405) are used for precisely and repeatably controlling actuation of the printing mechanism (60) in and out of position for printing and for precisely registering the component images being printed by the multiple printing stations (13). Each station (13) has a microprocessor based computer controller (407) for precisely registering the printing rollers (61) among each of the stations (13) and with respect to a preprinted component part of a composite image on a web (11) that may have been removed from and reinserted into the press (10), deforming in the process such that the repeat lengths of the preprinted parts have changed and may vary along the length of the web (11). Measurements are made by sensors (350) of a series of repeat lengths on the web (11), a regression analysis is performed and a prediction made of a constant or recurring component in the next image to be encountered at each respective station (13). The circumferential speed of the print roller (61) at each station (13) is separately controlled in accordance with a respective error prediction to control the length of the image printed at the station to that already on the web (11). The speed is controlled by pulses sent to a stepper motor (327) of a harmonic drive (275) at each station (13). The pulses are spaced evenly over the print length of the image.