To provide a sheet post-processing apparatus that can prevent a sheet bundle from being stapled while being disarranged after a paper jam is cleared away even when the same has occurred.
When an occurrence of a sheet jam in a sheet post-processing apparatus is detected, (a) the rotation of a discharge roller pair 23 disposed at a position to sandwich the sheet bundle vertically is stopped, and, while a brake is being put, the discharge roller pair 23 is caused to be in a pressure contact state through the sheet bundle, and (b) a pair of alignment plates 51 and 52 is moved to a position to abut against both side edges of the sheet bundle in the X-axis direction, and stopped so that the change in the attitude of the sheet is restricted, for the sheet bundle consisting of sheets S placed on a tray 50 for post-processing that are not stapled. After the restriction is performed, a staple unit 26 is moved from the binding position (a solid line) to a retracted position (a dashed line).
小林 国人
川畑 孝二
木村 公一