Patent ID: 7874553

Claim:
A sheet stacking apparatus comprising: a sheet discharging portion which discharges a sheet; a stacking portion which stacks the sheet discharged from the sheet discharging portion; a regulating portion which aligns an end portion in a discharge direction of a sheet bundle stacked on the stacking portion; and a rotating member which drops the sheet discharged from the sheet discharging portion on the stacking portion by applying a force to the discharged sheet from above and conveys the sheet in a direction opposite to the discharge direction of the sheet discharging portion to abut against the regulating portion; wherein the rotating member rotates at a first rotating speed so that the sheet discharged from the sheet discharging portion is dropped on the stacking portion and the rotating member rotates at a second rotating speed, slower than the first rotating speed, so that the sheet abuts against the regulating portion.