Sheet processing apparatus and image forming apparatus equipped with the same

An image forming apparatus comprising:

• an image forming portion which forms an image on a sheet;
• and
• a sheet processing apparatus which performs a processing on the sheets on which the images have been formed,
• said sheet processing apparatus comprising:
• a stacking portion which receives and stacks the sheet that is conveyed;
• a moving unit which moves the sheet conveyed to the stacking portion;
• a stopper which receives an end portion of the sheet moved by the moving unit;
• a load imparting portion which comes into contact with an upper surface of the sheet on the upstream side of the moving unit with respect to the sheet moving direction and imparts a load to the movement of the sheet,
• a stapler which staples the sheets stacked on the sheet stacking surface, wherein the stapler is an intermediate portion stapler which staples an intermediate portion of the sheets between the moving unit and the load imparting portion;
• a curved guide path which guides the sheet in a curved manner and which is provided on the upstream side of said stacking portion with respect to the direction in which the sheet is moved by the moving unit;
• and
• a folding device which folds the sheets stapled by the intermediate portion stapler in the curved guide path,
• wherein said moving unit moves the sheet to the stopper while the sheet is pulled by the load imparted by said load imparting portion,
• wherein said stacking portion has a flat sheet stacking surface,
• wherein said moving unit is arranged in the vicinity of the sheet stacking surface, and
• wherein said folding device comprises a pushing member extending through the curved guide path from the inner side to the outer side of a curved portion to push the sheets, and a folding portion which is pushed by the pushing member and receives and folds the sheets.