Patent ID: 7946563

Claim:
A post-processing apparatus for transferring sheets and post-processing on the sheets, the apparatus comprising: a sheet carry-in path arranged substantially horizontally for transferring the sheets fed from a carry-in port sequentially to a sheet discharging port; a first switchback conveying path branching downwardly from the sheet carry-in path from a position adjacent to the sheet discharging port so as to reverse a sheet conveying direction; a first post-processing section disposed at the first switchback conveying path to execute post-processing on the sheets in the first switchback conveying path; a second switchback conveying path branching downwardly from the sheet carry-in path between the carry-in port and the sheet discharging port upstream of the first switchback conveying path so as to reverse the sheet conveying direction transferred to the sheet carry-in path to transfer the sheets to a position under the first switchback conveying path; a second post-processing section located at the second switchback conveying path to execute post-processing on the sheets in the second switchback conveying path, a forward reversible sheet conveying roller located on the second switchback conveying path for temporarily holding, on the switchback conveying path, the sheet traveling to the first sheet collecting device positioned downstream of the sheet carry-in path, a sheet discharging roller located at the sheet discharging port of the sheet carry-in path; a sheet conveying roller located at a path inlet of the second switchback conveying path; and a conveyance control device for controlling the sheet discharging roller and the sheet conveying roller, wherein the conveyance control device controls the sheet discharging roller and the sheet conveying roller so that a succeeding sheet fed to the carry-in port stands by temporarily on the second switchback conveying path while the first post-processing section is performing a post-processing operation, and so that after the post-processing operation of the first post-processing section is finished, the succeeding sheet standing by on the second switchback conveying path is transferred to the first post-processing section, and wherein the first post-processing section comprises: a first sheet collecting device on which the sheets from the first switchback conveying path are set and collected into a bunch; and an end surface staple device for stapling the sheets collected on the first sheet collecting device, at an edge thereof, and the second post-processing section comprises: a second sheet collecting device on which the sheets from the second switchback conveying path are set and collected into a bunch; and one of folding roll device for folding together the sheets collected on the second sheet collecting device and a saddle stitching staple device for stapling the sheets at a center thereof.