Recirculating document feed for electrophotographic apparatus

Abstract

Documents are automatically recirculated for copying by a copier from a stack which is accessed top document downward. Documents are stacked faceup in an upper tray and moved as a group to a lower tray where they are stacked facedown, with the first document in the upper tray appearing in a facedown position at the bottom of the lower tray. The top document in the lower tray is then removed for copying and returned to the bottom of the upper tray, thus peserving the original document order for further copying. The copier normally scans stationary documents placed on a glass platen; for example, individual sheets of paper or book pages may be placed on the glass platen and held stationary while the optics causes light to scan the page. During automatic recirculation of stacks of the documents, however, the scanning optics is 'parked' and documents removed from the lower tray are imaged while scanned past a fixed exposure area on the glass platen on the way back to the upper tray.