Patent ID: 8292285

Claim:
A sheet processing apparatus that performs processing on sheets, comprising: a conveying unit configured to convey sheets along a conveying path; a buffer unit configured to convey a first sheet and a second sheet following the first sheet as a sheet bundle conveyed by said conveying unit in a state where the second sheet is superimposed on the first sheet and shifted from the first sheet in a conveying direction; a stacking unit configured to stack the first and the second sheets as the sheet bundle conveyed by said buffer unit; a determination unit configured to determine in advance, before a sheet conveyed by said conveying unit reaches said buffer unit, whether the sheet is a particular sheet having a protrusion on a leading side thereof in the conveying direction; and a control unit configured to control a shift amount in which the second sheet is shifted from the first sheet when the first and the second sheets are conveyed by said buffer unit, according to a result of a determination by said determination unit.