Patent ID: 7530568

Claim:
A double-sided document transport device for separating documents one by one from a bundle of the stacked documents, transporting a document to a reading position, and then transporting the document to the reading position again through a reverse path, the device comprising: main feed rollers constructed and arranged to transport a document separated from the stack of documents inward toward the reading position; transport rollers constructed and arranged to transport the document to the reading position, and from the reading position to a discharge position; and a discharge transport unit, comprising discharge rollers located at the discharge position, pinch rollers arranged under said discharge rollers, for pressing a document against the discharge rollers from under the discharge rollers, flappers having a wedge-shaped cross-section disposed between the transport rollers and the pinch rollers to switch a document transport direction, a document transported by the transport rollers toward the discharge position passing under and pushing the flappers upward, a document guide surface positioned above the flappers proximal the discharge position and between the discharge rollers and the transport rollers, a reversible drive, constructed and arranged to rotate the discharge rollers in a rotating direction changeable between a discharge direction and a reverse direction opposite the discharge direction, rotation in the reverse direction commencing when an end of a document having first passed the reading position reaches a nip region between the discharge rollers and the pinch rollers causing the document to pass over the flappers and under the document guide surface toward the transport rollers to again pass the reading position, and a discharge roller separation actuator constructed and arranged to selectively move the discharge rollers between a clamp position with the pinch rollers and upwardly away from the pinch rollers to separate the discharge rollers from the pinch rollers, the discharge roller separation actuator being operable to separate the discharge rollers from the pinch rollers after the document is engaged by the transport rollers, the reversible drive rotating the discharge rollers in the discharge direction and the discharge roller separation actuator moving the discharge rollers downwardly into contact with the pinch rollers when the end of the document is detected to discharge the document.