Copy system

An improved copy system includes a document feeding apparatus which is effective to move a document to an imaging station. An image on one side of the document is then projected on an electrostatically charged sheet to form a first master. The document is then transferred to an inverting mechanism which is effective to turn the document over and return it to the imaging station. A second master is then formed. The masters are sequentially transferred to a duplicating section which includes a printing unit. The printing unit utilizes the masters to print on one side of a sheet of material as it passes through a printing nip. During a printing operation, blank sheets are sequentially fed from a supply pile through the printing nip and the first master is utilized to print images on first or front sides of the sheets. The sheets which have been printed on only one side are then sequentially deposited in a hopper. After the sheets have been printed on one side, the first master is ejected from the printing unit and the second master is transferred to the printing unit. The sheets which have been printed on one side are then sequentially fed from the bottom of the hopper to the printing unit. As the sheets again pass through the printing nip, an image corresponding to the image on the second side of the document is printed on the second or back sides of the sheets. The equipment also exhibits features providing for printing sheets on both sides and for safe handling of the freshly printed sheets without smudging when the duplicator is of a type which employs wet ink in forming the copies.