Patent ID: 8393617

Claim:
A sheet alignment device for aligning a plurality of sheets on a sheet placement tray with each other, said sheet alignment device comprising: a first alignment arm for carrying first ends of said sheets, and comprising a first platform, a first sidewall, a first blocking piece and a second blocking piece, wherein said first platform is parallel with said sheet placement tray, said first sidewall is perpendicular to said first platform, and said first blocking piece and said second blocking piece are disposed over said first platform; a second alignment arm for carrying second ends of said sheets, and comprising a second platform, a second sidewall and a third blocking piece, wherein said second platform is parallel with said sheet placement tray, said second sidewall is perpendicular to said second platform, and said third blocking piece is disposed over said second platform; a power device and a transmission device, wherein said transmission device is connected with said power device, said first alignment arm and said second alignment arm, wherein through said transmission device, said first alignment arm is driven by said power device to be moved to a first home position, a first standby position and an alignment position, and said second alignment arm is driven by said power device to be moved to a second home position and a second standby position; a first sensor disposed over said first alignment arm for detecting a position of said first alignment arm; a second sensor disposed over said second alignment arm for detecting a position of said second alignment arm; and a controller for controlling movement of said first alignment arm and said second alignment arm, wherein if no sheet is placed on said sheet placement tray, said first alignment arm and said second alignment arm are controlled by said controller to be moved to said first home position and said second home position, wherein if said first sensor and said second sensor are respectively interrupted by said first blocking piece and said third blocking piece, said controller stops moving said first alignment arm and said second alignment arm, wherein when a first sheet is introduced into said sheet placement tray, said first alignment arm and said second alignment arm are controlled by said controller to be moved to said first standby position and said second standby position, respectively, wherein when said first sensor is interrupted by said second blocking piece, said controller stops moving said first alignment arm and said second alignment arm.