Patent ID: 8876107

Claim:
A sheet stacking device comprising: a stacking unit to stack thereon a sheet discharged in a sheet discharging direction; a conveying unit to perform a moving-back operation of conveying the stacked sheet in a direction opposite to the sheet discharging direction; a pressing unit to perform a pressing operation of pressing the conveyed sheet, the pressing unit including a pressing member, drivable by a cam attached to a first shaft, a second gear, attached to a second shaft configured to drive the cam, and a first gear to transmit rotation of the first shaft to the second shaft, wherein the conveying unit includes a return roller, attached to the first shaft, to rotate in synchronization with the first shaft; and a driving unit to drive the conveying unit and the pressing unit by a same driving source, the driving unit including a switching unit to switch between operation of the conveying unit and operation of the pressing unit in response to a rotating direction of the driving source.