Patent ID: 7869755
Filing Date: 2011-01-11
Classification: G03G

Abstract:
1. An automatic document feeder for transferring an original document through a scanning position three times, the automatic document feeder comprising: an original document stacker to accumulate a plurality of original documents; a first transfer mechanism to separate the plurality of original documents one by one from the original document stacker, reverse one of the plurality of original documents via a reversing path, and transfer the reversed original document to a scanning position; a second transfer mechanism to transfer the reversed original document from the scanning position to one of a switchback path and a document discharging part; a switchback mechanism to transfer the reversed original document to a lay-by on the switchback path, and transfer the reversed original document in a direction opposite to a previous travel direction thereof towards the reversing path via a re-entry path; and a control unit to control the first transfer mechanism, the second transfer mechanism, and the switchback mechanism, so that a second original document passes through the scanning position a first time before a first original document passes through the scanning position a third time, and so that the switchback mechanism pauses travel of the second original document at the lay-by as the first original document passes through the scanning position a third time enroute to the document discharging part, wherein: the control unit is further operable to drive the switchback mechanism to change the lay-by of the second original document after completion of the reading of a front face thereof and after completion of the reading of a reverse face thereof, so that the lay-by of the second original document after completion of the reading of the front face thereof is set closer to a set of discharging rollers of the second transfer mechanism than the lay-by of the first original document after completion of the reading of the reverse face thereof.