Patent ID: 7661669

Claim:
A sheet post-processing apparatus comprising: a sheet stacking unit that receives a plurality of sheets from an upstream apparatus and stacks the sheets in a pile thereon; an aligning unit that aligns the sheets stacked on the sheet stacking unit in a direction orthogonal to a conveying direction of the sheets; a moving member that moves up the pile of the sheets aligned by the aligning unit; a discharging member that receives the pile from the moving member and scoops up the pile by supporting a bottom edge of the pile for discharging the pile out of the sheet stacking unit; and a discharging motor that drives the discharging member in an operation pattern that is selected, depending on a predetermined condition, from among a plurality of operation patterns in which the discharging motor can drive, wherein, if a first operation pattern is selected, a driving linear speed of the discharging motor is at a second level when the discharging member receives the pile from the moving member, and the driving linear speed is increased to a first level that is higher than the second level after the discharging member receives the pile from the moving member, so that the discharging member discharges the pile with the driving linear speed at the first level.