Patent ID: 8905393

Claim:
A sheet post-processing apparatus that performs processing on a sheet having an image formed thereon, the sheet post-processing apparatus comprising: a post-processing unit configured to perform processing on a sheet and a sheet bundle, an upper limit value of the number of sheets that said post-processing unit is capable of processing at a time being equal to N, which is an integer, the upper limit value N being set according to a type of sheets; a buffer unit configured to perform buffer processing for retaining a conveyed sheet and conveying the retained sheet and at least one following sheet in a state placed one upon another as a sheet bundle; and a control unit configured to control said buffer unit and said post-processing unit so such that when said post-processing unit is performing the processing on the sheet or the sheet bundle, said buffer unit performs the buffer processing on a plurality of following sheets not larger in number than the upper limit value N, so that the processing is performed on each sheet bundle formed by the buffer processing, wherein when the upper limit value N is equal to one, said control unit causes the processing to be performed on each sheet without the buffer processing.