Sheet processing apparatus and image forming system

A sheet processing apparatus for performing folding processing in a plurality of portions of a sheet and performing the folding processing so that one end of the sheet exists inside the sheet folded, comprising:

• a transport path including a guide face to guide a sheet transported in a predetermined transport direction;
• a transport section adapted to be able to transport the sheet in a first direction for drawing the sheet transported to the transport path, and in a second direction for performing switchback on the drawn sheet in a direction opposite to the direction for drawing;
• a rotating body pair adapted to nip the sheet transported to the transport path by a nip portion to rotate, and thereby perform folding processing on the sheet, including a first circumferential surface with a radius to a rotating body circumferential surface being certain, and a second circumferential surface with a radius smaller than the radius of the first circumferential surface;
• a folding blade adapted to push the sheet transported to the transport path to the nip portion of the rotating body pair;
• a press member adapted to press the sheet, which is subjected to the folding processing by the rotating body pair and is transported in the second direction, to one direction side that is one of the transport direction and a direction opposite to the transport direction;
• a shift section adapted to shift the press member in a direction for pressing the sheet;
• and
• a control section adapted to control the transport section and the shift section,
• wherein in performing the switchback on the sheet subjected to the folding processing by the rotating body pair, the control section controls the transport section and the shift section so that the one end of the sheet subjected to the folding processing by the rotating body pair is pressed by the press member, within a region between a shift locus of the press member and the guide face of the transport path.

A sheet processing apparatus for performing folding processing in a plurality of portions of a sheet and performing the folding processing so that one end of the sheet exists inside the sheet folded, comprising:

• a transport path including a guide face to guide a sheet transported in a predetermined transport direction;
• a rotating body pair adapted to be able to transport the sheet in a first direction for nipping the sheet transported to the transport path by a nip portion to rotate, and thereby drawing the sheet to perform folding processing, and in a second direction for performing switchback on the sheet subjected to the folding processing in a direction opposite to the direction for drawing;
• a folding blade adapted to push the sheet transported to the transport path to the nip portion of the rotating body pair;
• a direction change member adapted to change a direction of the sheet, which is subjected to the folding processing by the rotating body pair and is transported in the second direction, to one direction side that is one of the transport direction and a direction opposite to the transport direction;
• a shift section adapted to shift the direction change member;
• and
• a control section adapted to control the rotating body pair and the shift section,
• wherein in performing the switchback on the sheet subjected to the folding processing by the rotating body pair, the control section controls the rotating body pair and the shift section so that the direction of the one end of the sheet subjected to the folding processing by the rotating body pair is changed by the direction change member, within a region between a shift locus of the direction change member and the guide face of the transport path.

A sheet processing apparatus for performing folding processing in a plurality of portions of a sheet and performing the folding processing so that one end of the sheet exists inside the sheet folded, comprising:

• a transport path including a guide face to guide a sheet transported in a predetermined transport direction;
• a transport section adapted to be able to transport the sheet in a first direction for drawing the sheet transported to the transport path, and in a second direction for performing switchback on the drawn sheet in a direction opposite to the direction for drawing;
• a rotating body pair adapted to nip the sheet transported to the transport path by a nip portion to rotate, and thereby perform folding processing on the sheet, including a first circumferential surface with a radius to a rotating body circumferential surface being certain, and a second circumferential surface with a radius smaller than the radius of the first circumferential surface;
• a folding blade adapted to push the sheet transported to the transport path to the nip portion of the rotating body pair;
• a direction change member adapted to change a direction of the sheet, which is subjected to the folding processing by the rotating body pair and is transported in the second direction, to one direction side that is one of the transport direction and a direction opposite to the transport direction;
• a shift section adapted to shift the direction change member;
• and
• a control section adapted to control the transport section and the shift section,
• wherein in performing the switchback on the sheet subjected to the folding processing by the rotating body pair, the control section controls the transport section and the shift section so that the direction of the one end of the sheet subjected to the folding processing by the rotating body pair is changed by the direction change member, within a region between a shift locus of the direction change member and the guide face of the transport path.