A double-side printing system has a printer section for printing images on the obverse side of a card, and a turning section for turning over the card sent out from the printer section and sending back the inverted card to the printer section so as to print various images on the reverse side of...http://www.google.fr/patents/US5806999?utm_source=gb-gplus-shareBrevet US5806999 - Double-side printing system
