Patent ID: 7758035

Claim:
A sheet post-processing apparatus which executes a post-process on a sheet bundle, the sheet post-processing apparatus comprising: a post-processing device for executing the post-process on the sheet bundle; an intermediate stacker which is provided upstream of the post-processing device in a sheet conveyance direction for stacking sheets to be post-processed; a first conveying roller ( 103 ) which is provided upstream of the intermediate stacker in the sheet conveyance direction, a pressing force of the first conveying roller ( 103 ) against a facing roller being variable; and a controller for controlling the pressing force of the first conveying roller ( 103 ), wherein after a leading edge of a first sheet to be assigned to a succeeding sheet bundle goes through the first conveying roller ( 103 ) while the post-processing device executes the post-process on a preceding sheet bundle, the controller changes a pressing force of the first conveying roller ( 103 ) from a first pressing force to a second pressing force which is smaller than the first pressing force, and then the controller changes the pressing force of the first conveying roller ( 103 ) to the first pressing force after a leading edge of a second sheet to be assigned to the succeeding sheet bundle goes through the first conveying roller ( 103 ).