SHEET PROCESSING DEVICE AND IMAGE FORMING APPARATUS

PROBLEM TO BE SOLVED: To improve alignment of sheet-conveyance-direction ends of buffered sheets.SOLUTION: A sheet processing device includes: a branch path which is provided midway through a guide path for guiding sheets and which makes the sheets stored in the state of being stacked in such a manner as to be displaced from one another in a sheet conveyance direction; a processing tray 303 for being loaded with the sheets fed out from the branch path; a return roller 400 which is brought into contact with the sheet loaded with the processing tray and rotated to move the sheet in the sheet conveyance direction; a stopper 307 which receives a sheet-conveyance-direction end of the sheet to be moved by the return roller; and a swing roller 301a which moves the sheet, loaded on the processing tray, to a position of the return roller 400. Since the amount of shift of the sheets in the sheet conveyance direction by the branch path is set equivalent to a length exceeding the length of an interval between the return roller 400 and the stopper 307, the return roller enables the sheets to abut on the stopper one by one.