Patent ID: 7073436

Claim:
A duplex printing device in which a duplex printing master, on which a first image and a second image are perforated in series over the length of a single plate, or a simplex printing master, on which a third image having an image area equivalent to said first image and said second image is perforated over the length of a single plate, is wrapped around an outer peripheral surface of a print drum, thereby enabling a duplex printing operation in which one of said first image and said second image is printed by pressing a front side of a sheet against said duplex printing master on said print drum using pressing means which can be brought into and out of contact with said print drum, after which the other of said first image and said second image is printed by reversing and refeeding said sheet and pressing a reverse side of said sheet against said duplex printing master on said print drum using said pressing means, and a simplex printing operation in which said third image is printed by pressing one side of said sheet against said simplex printing master on said print drum, wherein a preset initial set mode can be switched between a duplex print mode for performing said duplex printing operation and a simplex print mode for performing said simplex printing operation when power is supplied to said duplex printing device, during mode clearance for clearing various modes executed by said duplex printing device.