Patent ID: 7665729

Claim:
A sheet processing apparatus comprising: a waiting tray that temporarily holds a sheet; a processing tray arranged below the waiting tray; a paddle unit including a first paddle that taps a trailing end of the sheet held in the waiting tray and drops the sheet onto the processing tray and a second paddle that draws the sheet on the processing tray to perform alignment in a sheet conveying direction; and a control unit configured to control pivoting of the paddle unit to tap the trailing end of the sheet with the first paddle during the drop onto the processing tray, after stopping once, apply the alignment in the sheet conveying direction to the sheet with the second paddle, and complete the dropping and the alignment by rotating once, wherein an interval Q1 between the first paddle and the surface of the sheet on the processing tray and an interval Q2 between the second paddle and the surface of the sheet on the processing tray are controlled to be in a relation Q1≦Q2and, when a number of sheets stacked on the processing tray increases, the interval Q1 and the interval Q2 are controlled to be in a relation 0≦Q1<Q2.