RECIRCULATIVE DOCUMENT DUPLEX COPYING
Original Publication Date: 1983-Dec-31
Included in the Prior Art Database: 2004-Apr-04
Xerox Disclosure Journal
In a system for recirculative precollation copying of a set of simplex document sheets in reverse serial order on a copier providing a choice of precollated simplex or duplex (two-sided) copy sheet copying, as in U.S. Patents 4,330,197 and 4,278,344 more efficient duplex copying without an initial document counting circulation is provided by assuming that the copy sheets selected for duplex copying are non-orientation sensitive copy sheets such as plain paper (rather than special orientation restricted copy sheets requiring consistent inversion for proper output or binding edge orientation, such as sheets prepunched with binder holes, certain preprinted sheets, etc.) by making an initial assumption as to whether there are an odd or even number of simplex document sheets in the set of document sheets before they are counted, by making a selection of whether it is desired to copy odd or even document sheets in the first circulation of the document set for copying, then, in response to this initial assumption and selection and choice of duplex copying, automatically circulating the set of document sheets for copying onto first sides of copy sheets on the first circulation of the document set, before the documents have been counted, wherein the copying of document sheets on the first circulation is restricted to copying those alternate document sheets in accordance with the assumption and selection, placing these first copy sheets as a buffer set in the duplexing tray as described in said patents, counting the number of document sheets during the first copying circulation to actually determine whether there are an odd or even number, then automatically in the second circulation, in response to this actual determination, copying only the other alternate document sheets (not copied in the first circulation) twice (onto two copy sheets)f the initial assumption was erroneous, or automatically copying all of the document sheets - n c e if the initial assumption was correct.