Patent ID: 8814157

Claim:
A sheet processing apparatus comprising: a sheet stacking unit where sheets to be processed are stacked; a regulating member configured to abut on one edge of sheets conveyed to the sheet stacking unit in a sheet conveyance direction to regulate position of a sheet in the sheet conveyance direction; a sheet waiting unit configured to keep sheets waiting, stack the waiting sheets displaced sequentially so that a lower sheet will be positioned closer to the regulating member than an upper sheet after the displaced sheets are conveyed to the sheet stacking unit, and then convey the displaced sheets to the sheet stacking unit; a first moving unit configured to sequentially move the sheets conveyed to the sheet stacking unit, starting from a lowermost sheet, to be abutted against the regulating member; a second moving unit disposed upstream of the first moving unit in a moving direction, and configured to move the sheets conveyed to the sheet stacking unit to the first moving unit; and a control unit configured to control the second moving unit to move a next sheet so that the next sheet does not reach the first moving unit until after the sheet moved by the first moving unit is abutted against and stopped by the regulating member.