Layout and page sequence control method for double sided printing process, uses drive and nip roll mechanism to transport paper between devices printing on opposite sides

摘要

Paper (3) supplied to a first printing device (1) with the aid of drive and nip rolls (7) so that it is printed on the front side, then it is supplied to a nip device with stop rolls (11). The printed paper is optionally cut on the rear side and supplied to the starting end of a mirror symmetrical second printing device (2), in which the leading edge of the paper is passed through a nip and guided upwards by drive and nip rolls (15), so that it is printed on the back side. The double-sided printed paper is ejected and the page layout and the sequence between the pages on the two sides of the paper are checked. An Independent claim is also included for the printing machine used to carry out this method, comprising two printing devices which are essentially the same type, each with its own printer (7, 8), designed so that the leading edge of the paper entering the second printing device is the same leading edge as when the paper entered the first printing device.