Sheet processing apparatus and image forming system having the same

An image forming apparatus, comprising:

• an image forming device which forms an image on a sheet,
• a stack portion on which sheets conveyed in a conveying direction from the image forming device are stacked;
• a first regulator which is configured to regulate a position of a sheet bundle stacked on the stack portion, the first regulator regulating the position of the sheet bundle in a crossing direction crossing the conveying direction by contacting an end of the sheet bundle in the crossing direction;
• a second regulator which is configured to regulate a position of a sheet bundle, stacked on the stack portion, in the conveying direction by contacting an end of the sheet bundle in the conveying direction;
• a first binder which is configured to move in the crossing direction so that the first binder moves from a first side of the sheet processing apparatus to a second side of the sheet processing apparatus and moves from the second side to the first side, and which is configured to bind a corner portion of a sheet bundle by a staple at a first position, the corner portion including an end where the first regulator has contacted and an end where the second regulator has contacted, the corner portion being on the first side of the sheet bundle, the first binder being configured to bind a corner portion of a sheet bundle, which is stacked on the stack portion, by a staple at a second position, the corner portion including an end which is on the second side of the sheet bundle which is stacked on the stack portion and an end where the second regulator has contacted, the corner portion being on the second side of the sheet bundle;
• a second binder which is configured to bind a corner portion of a sheet bundle without a staple, the corner portion including an end where the first regulator has contacted and an end where the second regulator has contacted, the corner portion being on the first side of the sheet bundle, the second binder including a first pressurizing portion and a second pressurizing portion, the first pressurizing portion and the second pressurizing portion sandwiching the sheet bundle in a case that the second binder binds the sheet bundle, the first pressurizing portion and the second pressurizing portion being configured to move integrally, the second binder being movable on the first side of the first binder located at the second position, the second binder not being movable on the second side of the first binder located at the second position;
• and
• a controller configured to move the first binder in the crossing direction, the controller being configured to bind a corner portion of a sheet bundle by the first binder, the corner portion including an end where the first regulator has contacted and an end where the second regulator has contacted, the corner portion being on the first side of the sheet bundle,
• the controller being configured to bind a corner portion of a sheet bundle, which is stacked on the stack portion, by the first binder, the corner portion including an end which is on the second side of the sheet bundle which is stacked on the stack portion and an end where the second regulator has contacted, the corner portion being on the second side of the sheet bundle,
• the controller being configured to bind a corner portion of a sheet bundle without a staple by the second binder, the corner portion including an end where the first regulator has contacted and an end where the second regulator has contacted, the corner portion being on the first side of the sheet bundle,
• the controller being configured to move the second binder on the first side of the first binder located at the second position, the controller not moving the second binder on the second side of the first binder located at the second position.