Automatic document feeder with improved sheet handling capabilities and method of feeding and scanning over-sized media sheets

Abstract

An automatic document feeder (ADF) has a paper path that starts with an input tray, leads to an operational station such as a scanner, and then ends with a substantially vertical output tray. The ADF has a mechanism for picking off an individual media sheet from a stack of sheets in the input tray and propelling the sheet to the operational station where a function is performed on the sheet. Thereafter the ADF propels the sheet partially into the output tray, and momentarily stops or reverses the direction of travel of the media sheet before finally driving the entire sheet into the output tray. This ensures that if the topmost sheet in a stack in the output tray which is being lifted up by the sheet being driven into the output tray, the topmost sheet will be fall back down to a rest position in the output tray and will not spill out of the output tray. The combination ADF and scanner can be operated so that it will automatically detect whether a standard-sized sheet of media is being fed into the scanner in landscape orientation or an over-sized sheet of media is being fed into the scanner in portrait orientation. In the case of the latter, first and second portions of the over-sized sheet are successively registered over the transparent platen of the scanner and scanned. The over-sized sheet is thereafter ejected from the scanner into an output tray. The resulting digital images of the first and second portions of the over-sized sheet are rotated, stitched together by a control circuit using software and/or firmware algorithms and the complete image of the over-sized sheet is stored in a memory, faxed or printed.