SHEET POSTPROCESSING DEVICE

摘要

PROBLEM TO BE SOLVED: To attain size reduction in a sheet postprocessing device, and prevent carrying failure by performing width directional sheet registering processing and shift processing to sort sheets with every sheet number, and arranging the specific number of independently movable aligning members on the width directional both sides orthogonal to the sheet carrying direction. SOLUTION: In the case of a sheet P1 of the ordinary size, two aligning plates 91A and 91B respectively align a width by beating the side edge of the sheet P1 by moving to a position slightly narrower than a paper width every time when the sheet P1 is sent into the vicinity of staplers 10A and 10B. After the prescribed number of sheets P1 reach a tip part 14A of a discharge arm, a staple is driven by either one or both of the staplers 10A and 10B. Afterwards, rear end parts of the sheets P1 are discharged to a paper discharge tray by a tip part 14A of the discharge arm (a). In the case of a sheet P2 of the small size, every time when it comes into contact with the tip part 14A, one aligning plate 91B pushes the side edge, and shifts it to one side, and a staple is driven (b) after the other aligning plate 91A aligns a width.