US Patent 7617770 Stencil printing apparatus capable of duplex printing

In a stencil printing apparatus capable of duplex printing, in which a front surface printing process for printing a front surface image on one surface of a sheet of paper fed by a sheet feeding unit is performed, the sheet is re-fed to a sheet re-feeder, and then a rear surface printing process for printing a rear surface image on the other surface is performed. The positions of the front surface image and rear surface image to be formed on the sheet can be moved together by a predetermined amount in a single direction side of a sheet conveyance direction.