Patent ID: 8226076

Claim:
A post-processing apparatus which produces a booklet by applying a center-folding process or a saddle-stitching process to a sheet, the post-processing apparatus comprising: a sheet ejection section for ejecting the sheet; a sheet tray for storing thereon the sheet ejected from the sheet ejection section; a regulating section for aligning the sheet stored on the sheet tray by coming in contact with an edge of the sheet; a drive section for moving the regulating section in a direction of sheet ejection or an opposite direction from the direction of sheet ejection; a control section for moving the regulating section by controlling the drive section such that a third sheet falls onto a sheet surface of a second sheet stored as a top of sheets on the sheet tray when the third sheet is ejected from the sheet ejection section in a situation where the second sheet which has a smaller size than a first sheet in the direction of sheet ejection is stored on the first sheet on the sheet tray; and a processing section for applying the center-folding process or the saddle-stitching process to a bundle of sheets including a plurality of sheets aligned by the regulating section and stored on the sheet tray.