Abstract: A document feeder of the invention is formed of a sheet feeding tray for receiving sheets or documents thereon; a feeding device for feeding the sheets on the sheet feeding tray in order; and a feeding roller for feeding the sheets transferred from the feeding device in a sheet feeding direction and having at least one space extending in a direction perpendicular to the sheet feeding direction. The document feeder further includes at least first and second separating devices. The first separating device is formed of a frictional member having a frictional coefficient relative to a sheet greater than that between the sheets. The first separating device contacts the feeding roller and permits one sheet to pass therebetween. The second separating device is formed of an elastic member and has at least one tongue piece with a forward end. The forward end is located in the space of the feeding roller for separating the sheets between the forward end and the feeding roller.

Abstract: A document feed roller and registering rollers are driven through first and second one-way clutches so that the feed roller connected to the motor through the first one-way clutch is driven to forward a document to be processed only when the motor rotates in a positive direction, and the registering rollers connected to the motor through the second one-way clutch are driven to perform skew-correction and forward the document only when the motor rotates in a negative direction. The document is transported for a first part of a document feeding passage by the feed roller and for a second part of the passage by the registering rollers with efficiency merely by switching the rotational direction of the motor.