Patent ID: 7360958

Claim:
A sheet processing apparatus for processing sheets on which images have been formed by an image forming apparatus, comprising: a sheet accepting unit that accepts sheets from the image forming apparatus; a cutting unit comprising a circular blade that cuts the sheets accepted by the sheet accepting unit with the blade that is moved in a direction perpendicular to a sheet transport direction; and a recognizing unit that identifies at least one of a number and grams per square meter of sheets to be cut in the form of a sheaf, a movement condition of the blade being determined on the basis of at least one of the number and grams per square meter of sheets identified by the recognizing unit, wherein the recognizing unit further identifies a center registration method that positions the cutting unit to a job start position from a home position to cut the sheet, and a side registration method that positions the cutting unit to the home position to cut the sheet; wherein a starting position of the cutting unit to cut the sheet is controlled according to the identified registration method.