Hybrid sequenced document copying system

Abstract

Disclosed is a hybrid copying system comprising a document feeder for a copier with a document bypass loop for copying documents in desired non-linear page sequences for improved copying efficiency, particularly for duplex copying. As shown, documents from a stacked set of document sheets may be fed to the copying station of the copier and then selectively returned directly back to the opposite side of the copying station for copying interleaved between the feeding of other documents fed from the stack, by a document return loop bypass path bypassing the stack and having a path length greater than the dimension of a document sheet. At least one document which has been copied on one side may be moving in this return loop bypass path while another fed from the stack is being copied, and may also be inverted by an integral inverter therein. For precollation copying this document bypass loop may be coordinated with otherwise normal recirculation of the documents to and from the stack in an integrated but partially different loop path. Coordinated copy sheet duplexing systems are provided for improved efficiency duplex copying, preferably comprising a trayless duplexing loop buffer path for circulating copy sheets from and back to the image transfer station of the copier to eliminate intermediate copy sheet stacking and refeeding between first and second side copying. Various examples are provided for hybrid simplex and/or duplex and pre or post collation copying, including coordinated hybrid or non-sequential postcollation sorter operation.