Patent ID: 8730541

Claim:
A duplex scanning apparatus for scanning a first side and a second side of at least one document, said duplex scanning apparatus comprising: a flatbed scanning portion having a first scanning module for scanning said first side of said at least one document, wherein said first scanning module has a first normal line perpendicular to a horizontal plane; and an automatic document feeder disposed over said flatbed scanning portion for transporting said at least one document and scanning said second side of said at least one document, wherein said automatic document feeder comprises: a sheet transfer channel disposed within said automatic document feeder for allowing said at least one document to go through, wherein said sheet transfer channel has a channel entrance; a second scanning module disposed in said sheet transfer channel and located near said channel entrance for scanning said second side of said at least one document, wherein said second scanning module has a second normal line, and an included angle is defined between said first normal line and said second normal line; a sheet input tray located near said channel entrance for placing said at least one document thereon; a sheet ejecting tray disposed under said sheet input tray and near a channel exit of said sheet transfer channel, wherein after said at least one document has been scanned, said scanned document is placed on said sheet ejecting tray; a sheet pick-up module located beside said sheet input tray and near said channel entrance for transporting said at least one document into said sheet transfer channel through said channel entrance; a first scanning region disposed over said first scanning module of said flatbed scanning portion; a second scanning region disposed over said second scanning module; and plural roller assemblies disposed in said sheet transfer channel for transporting said at least one document to said first scanning region, said second scanning region or said sheet ejecting tray, wherein said plural roller assemblies comprise: a transfer roller assembly disposed in a bent segment of said sheet transfer channel for transporting said at least one document to said first scanning region; and a shared roller assembly disposed beside said channel entrance and said channel exit for transporting said at least one document from said channel entrance to said second scanning region or transporting said at least one document from said first scanning region to said sheet ejecting tray.