Patent ID: 7896331

Claim:
A sheet post-processing apparatus comprising: a stacking tray on which sheets are stacked; an aligning unit configured to align the sheets stacked on the stacking tray to a reference position; a staple which staples the sheets aligned by the aligning unit using two members dividedly provided on one surface side and the other surface side in a thickness direction of the sheets; first conveying rollers arranged in a position for nipping one end of the sheets on an upstream side of the stapler along a conveying direction of the sheets and driven to rotate after the stapling by the stapler; and second conveying rollers arranged in a position for nipping the other end of the stapled sheets on a downstream side of the stapler along a conveying direction of the sheets stapled by the stapler a motor which drives the first conveying rollers and the second conveying rollers at a predetermined rotation speed independently; and a controller which changes a time when the first conveying rollers and the second conveying rollers are driven by the motor, wherein the first conveying rollers are driven to rotate at a rotation speed higher than a rotation speed of the second conveying rollers for a first predetermined time after the stapling by the stapler.