Abstract: The invention provides an image reader provided with an automatic document feeder which has a switchback path and can perform a both-faces processing operation, and which makes it possible to simplify the control of a switchback operation and handle a long-sized document sheet without making the diameter of a feed roller large and making the switchback path unnecessarily long. An automatic document feeder of the invention comprises a feed path for feeding a document sheet drawn out from a paper feed stacker to an image reading portion facing a feed roller, a switchback path c for making a document sheet which has been processed at the image reading portion switchback, a pair of switchback rollers which are provided so as to make a document sheet switchback in the switchback path and are able to turn forward and backward, and a paper discharge path for discharging a document sheet being in the switchback path onto a paper discharge stacker.

Abstract: There are provided a separation unit, which is formed of a feed roller that touches the uppermost surface of sheets stacked on a sheet supply tray to feed the sheet, a supply roller to supply the drawn out sheet, and a separating member pressing against the supply roller to allow only the uppermost sheet to pass; and a guide member, which is disposed between the sheet supply tray and the separating member with an angle with respect to the sheet supply tray drawn from the feed roller to guide the sheet to the supply roller and also abuts against leading edges of the sheets drawn out from the feed roller to separate them. Since the separating member of a separating mechanism and the guide member are mounted on the same holder so that the separating member of the separating mechanism and the guide member are attached and detached as a single body to the guide member for guiding the sheets.

Abstract: The invention provides an image reader provided with an automatic document feeder which has a switchback path and can perform a both-faces processing operation, and which makes it possible to simplify the control of a switchback operation and handle a long-sized document sheet without making the diameter of a feed roller large and making the switchback path unnecessarily long.

Abstract: An automatic document feeding apparatus includes a document supplying mechanism having a supply passage incorporating at least one kick roller, pressure mechanism, document separating mechanism and registering mechanism so as to send documents one by one toward a document reading station defined on an image forming apparatus such as a copying machine, a document transferring mechanism for moving the document along the document reading station to read out or copy the document, and a document discharging mechanism having a discharge passage for sending out the processed document and a return passage for inverting and sending back the processed document to the document reading station. The document supplying mechanism, document transferring mechanism and document discharging mechanism can be arbitrarily driven by controlling a single drive source, two electromagnetic clutches and one-way clutches constituting a motion transmitting system.