Patent ID: 8522660

Claim:
A sheet processing apparatus comprising: a cutting unit which cuts a sheet into a cut sheet and cutting waste; a conveying unit which conveys the sheet cut by the cutting unit; a detection unit which detects a passage of the sheet conveyed by the conveying unit; and a controller which determines a length in the sheet conveying direction of the conveyed sheet based on a detection result of the detection unit, wherein the controller determines that the sheet is cutting waste when a determined length in the sheet conveying direction of the conveyed sheet is equal to or less than a predetermined length, the controller determines that the sheet is a cut sheet when the determined length in the sheet conveying direction of the conveyed sheet is longer than the predetermined length, and when the detection unit is in a sheet detection state before the sheet begins to be conveyed by the conveying unit, the controller controls the conveying unit so that the sheet is conveyed by a conveying amount corresponding to the predetermined length in the sheet conveying direction, and when the detection unit stops detecting the sheet after the sheet is conveyed by the conveying amount, the controller determines that the sheet is cutting waste.