Patent ID: 8547560

Claim:
A sheet processing apparatus, comprising: a processing tray on which sheets transported in a predetermined delivery direction are accumulated; a binding device configured to bind one side on an upstream side in the delivery direction of the sheets accumulated on the processing tray; a gripping device configured to grip the one side of the sheets bound by the binding device; a first moving mechanism configured to move the binding device in a direction intersecting the delivery direction along the one side of the sheets accumulated on the processing tray; a second moving mechanism configured to move the sheets in the delivery direction by moving the gripping device in the delivery direction at a time of delivering the sheets; and a control unit configured to control the binding device by the first moving mechanism and control the gripping device by the second moving mechanism, wherein, in a case that the binding device is moved by the first moving mechanism to an opposite side of the gripping device in a direction along the one side, the control unit causes the second moving mechanism to move the gripping device to a retreat position at which the gripping device is prevented from prohibiting movement of the binding device, before a first sheet of a sheet bundle to be stacked is transported to the processing tray, and the control unit causes the second moving mechanism to move the gripping device to a region at which the binding devices moves, after the binding device is moved to the opposite side of the gripping device.