Patent ID: 8870177

Claim:
A sheet processing apparatus, comprising: an ejection section which ejects a bundle of sheets on which predetermined processing is performed; a sheet stacking section on which the sheet bundle ejected by the ejection section is stacked; an abutting unit which is provided near a base end portion of the sheet stacking section and abuts a rear end of the sheet bundle; a driving section which moves the sheet stacking section upward and downward; a control section which lowers the sheet stacking section by controlling the driving section when the sheet bundle is stacked on the sheet stacking section; and a rotating member which has a rotating shaft in parallel with a width direction of the sheet bundle and is held so as to rotate from above the base end portion of the sheet stacking section through a gap of a predetermined width in the abutting unit; wherein the control section starts rotation of the rotating member after lowering of the sheet stacking section is stopped, and when the rotation is started, the rotating member operates so as to abut a rear portion of a surface of the sheet bundle stacked on the sheet stacking section and pass through the gap in the abutting unit.