Medium transport device and medium transport method

A medium transport method for a medium transport device, the medium transport device including:

• a placement section on which a medium is placed;
• a feed roller configured to feed the medium from the placement section in a feed direction;
• a separation roller that is configured to rotate in a rotation direction which moves the medium in a reverse feed direction, which is a direction toward the placement section and which is opposite to the feed direction, and that is configured to nip the medium together with the feeding roller to separate a sheet of medium from a stack of sheets of the medium;
• a drive mechanism section for driving the feed roller and the separation roller;
• a drive section that generates a driving force;
• and
• a one way clutch section that is provided in a transmission path, that transmits the driving force to the feed roller, the one way clutch comprising a sliding locking section operatively coupled to a transport roller, wherein movement of the sliding locking section in a direction along the rotation shaft is synchronized with movement of the transport roller between a separated state where the transport roller is separated from the medium and a contacted state where the transport roller is in contact with the medium, and that configured to switch between
• an allowed state in which the one way clutch section allows the feed roller to rotate in a rotation direction in which the feed roller moves the medium in the reverse feed direction and the transport roller is moved upwards to the separated state, and
• a restricted state in which the one way clutch section allows the feed roller to rotate only in a rotation direction in which the feed roller moves the medium in the feed direction and the transport roller is moved downwards to the contacted state,
• the medium transport method comprising:
• a feeding step of feeding the medium in the feed direction by nipping the medium between the feed roller and the separation roller and
• a subsequent medium returning step of causing the one way clutch section to enter the allowed state and of rotating the separation roller in the rotation direction in which the medium moves in the reverse feed direction to return, in the reverse feeding direction, a subsequent medium, which is a medium subsequent to a preceding medium transported in the feeding step.