Patent ID: 8200139

Claim:
A duplex document scanning apparatus comprising: a scan unit including a reader, the scan unit sequentially scans images of both sides of a sheet by moving the sheet across the reader; and a reverse output unit to receive the sheet from the scan unit after the images of both sides of the sheet have been scanned and to output the sheet after turning over the sheet, wherein the scan unit comprises: a document input unit to feed the sheet of the duplex document; and a scan side changer to temporarily store the sheet after a first side of the sheet has been scanned by the reader and to guide the sheet back to pass the reader so that a second side of the sheet faces the reader, wherein the reader scans both sides of the sheet fed from the document input unit, wherein the scan side changer comprises: a scan side changer tray to temporarily support the sheet after the first side of the sheet has been scanned by the reader; and scan side changer rollers to rotate in a forward direction to feed the sheet to the scan side changer tray after the first side of the sheet has been scanned and to rotate in a reverse direction to feed the sheet back to pass the reader, and wherein the reverse output unit comprises: a reverse output tray to temporarily support the sheet after both sides of the sheet have been scanned; a final output tray onto which the sheet is discharged from the reverse output tray; stack side reverse rollers to rotate in a forward direction to move the sheet onto the reverse output tray after both sides of the sheet have been scanned and to rotate in a reverse direction to move the sheet from the reverse output tray to the final output tray; and final output rollers to receive the sheet from the stack side reverse rollers when the stack side reverse rollers rotate in the reverse direction and to transfer the sheet onto the final output tray, wherein the sheet is turned over between the reverse output tray and the final output tray.