Patent ID: 8096553

Claim:
A sheet stacking apparatus comprising: a plurality of stacking portions, on which the sheets are stacked, configured to move up and down respectively; a discharging portion configured to discharge a sheet onto one of the plurality of stacking portions selectively; a single guiding unit which is movable according to the one stacking portion selected from the plurality of stacking portions, the single guiding unit including a stopper which stops an edge of the sheet in a sheet discharging direction of the discharging portion at a predetermined position on the one stacking portion selected from the plurality of stacking portions, and a guide member configured to guide the sheet discharged by the discharging portion to the stopper; and a control unit configured to control the single guiding unit and the plurality of stacking portions so that, when the single guiding unit moves from a stacking portion selected first to a stacking portion selected next, the single guiding unit moves to the stacking portion selected next after the stacking portion selected first moves down.