Patent ID: 7658372

Claim:
A sheet processing apparatus comprising: a stapler; a conveying path along which a sheet is conveyed to said stapler; a bundle forming device disposed in said conveying path for superposing received sheets one upon another to form a sheet bundle, said bundle forming device having a pinch device, which successively pinches an upstream end portion of the sheet one-by-one and integrally pinches a plurality of sheets; a control portion, which controls said stapler and said bundle forming device to staple the sheet bundle by said stapler selectively between at one end of the sheet bundle in a conveying direction of the sheet bundle for a side stitching of the sheet bundle, and on a fold line of the sheet bundle for a saddle-stitching of the sheet bundle; a discharging device, which discharges the sheet bundle stapled at the one end; a stacking portion on which the sheet bundle discharged by said discharging device is stacked; a two-fold device, which folds the sheet bundle stapled on the fold line in two along the fold line, wherein the sheet bundle folded by said two-fold device is stacked on said stacking portion; and a housing structure in which said stacking portion is disposed, wherein said stacking portion is defined in a space area downstream of said discharging device and lower than said discharging device.