Problem: To make it possible to bind a large amount of booklets in a short period of time by using a book binding apparatus efficiently.

Solution: A book binding apparatus 10 includes a book binding part 11 which binds a booklet, a book binding control part 12 which controls the book binding part 11 based on book binding information, and a book binding apparatus side book binding information setting part 13 which sets the book binding information. A paper feeding apparatus 20 includes a feeding part 21 which feeds a recorded paper one sheet by one sheet, a feeding control part 22 which controls the feeding part 21 based on the book binding information, and a paper feeding apparatus side book binding information setting part 23 which sets the book binding information. The book binding apparatus 10 and the paper feeding apparatus 20 can be communicated with each other. Based on the book binding information set in the book binding apparatus side book binding information setting part 13 or the paper feeding apparatus side book binding information setting part 23, the recorded paper is fed from the paper feeding apparatus 20 to the book binding apparatus 10 one sheet by one sheet and the recorded papers are bundled and bound by the book binding apparatus 10.

The present invention is to enable folding processing to be applied to also large sheet sizes without upsizing the entire apparatus, in the sheet post-processing apparatus for performing the folding processing and binding processing on sheets, a sheet post-processing apparatus is provided with a binding processing section for performing binding processing using a binding needle on a sheet bunch inside a storage section, first folding roller pair for nipping a sheet P inside the storage section in a first position to form a first fold portion, a receiving section for receiving the sheet with the first fold portion formed fed out of the first folding roller pair, and second folding roller pair for nipping the sheet inside the receiving section in a second position to form a second fold portion.

The present invention is to enable folding processing to be applied to also large sheet sizes without upsizing the entire apparatus, in the sheet post-processing apparatus for performing the folding processing and binding processing on sheets, a sheet post-processing apparatus is provided with a binding processing section for performing binding processing using a binding needle on a sheet bunch inside a storage section, first folding roller pair for nipping a sheet P inside the storage section in a first position to form a first fold portion, a receiving section for receiving the sheet with the first fold portion formed fed out of the first folding roller pair, and second folding roller pair for nipping the sheet inside the receiving section in a second position to form a second fold portion.

A binding processing apparatus includes a pair of pressing members each including a concave-convex portion configured to form a concave part and a convex part in a recording material bundle. The concave-convex portion includes protrusion portions. Aside surface of each protrusion portion is inclined so that the protrusion portion is widened from an apex of the protrusion portion. The side surfaces of the protrusion portions of a first pressing member that is one of the pressing members and the side surfaces of the protrusion portions of a second pressing member that is the other of the pressing members intersect with each other during pressing when viewed in a column direction of the protrusion portions.

A binding processing apparatus includes a pair of pressing members each including a concave-convex portion configured to form a concave part and a convex part in a recording material bundle. The concave-convex portion includes protrusion portions. Aside surface of each protrusion portion is inclined so that the protrusion portion is widened from an apex of the protrusion portion. The side surfaces of the protrusion portions of a first pressing member that is one of the pressing members and the side surfaces of the protrusion portions of a second pressing member that is the other of the pressing members intersect with each other during pressing when viewed in a column direction of the protrusion portions.

There is provided an image forming system including an apparatus body including an image forming unit configured to form an image on a sheet, a first sheet processing device mounted on the apparatus body, and configured to perform a first binding processing on plural sheets each of which is formed with an image by the image forming unit, and a second sheet processing device mounted on the apparatus body at a position different from that of the first sheet processing device, and configured to perform a second binding processing different from the first binding processing on the plural sheets, each of which is formed with an image by the image forming unit.

There is provided an image forming system including an apparatus body including an image forming unit configured to form an image on a sheet, a first sheet processing device mounted on the apparatus body, and configured to perform a first binding processing on plural sheets each of which is formed with an image by the image forming unit, and a second sheet processing device mounted on the apparatus body at a position different from that of the first sheet processing device, and configured to perform a second binding processing different from the first binding processing on the plural sheets, each of which is formed with an image by the image forming unit.

A binding processing apparatus includes: a pressure-applying member pair that has multiple projections arranged side-by-side and applies pressure to a sheet stack by pressing the projections against the sheet stack; and an advancing-and-retracting part that causes at least one of the pressure-applying members in the pressure-applying member pair to move toward or away from the other pressure-applying member. A pitch of the projections in each pressure-applying member is from 1.2 mm to 1.5 mm, and a height of the projections is from 0.55 mm to 0.75 mm, and a load per unit area applied from each pressure-applying member to the sheet stack when the pressure-applying member applies pressure to the sheet stack is from 42 N/mm.sup.2 to 94 N/mm.sup.2.

A binding processing apparatus includes: a pressure-applying member pair that has multiple projections arranged side-by-side and applies pressure to a sheet stack by pressing the projections against the sheet stack; and an advancing-and-retracting part that causes at least one of the pressure-applying members in the pressure-applying member pair to move toward or away from the other pressure-applying member. A pitch of the projections in each pressure-applying member is from 1.2 mm to 1.5 mm, and a height of the projections is from 0.55 mm to 0.75 mm, and a load per unit area applied from each pressure-applying member to the sheet stack when the pressure-applying member applies pressure to the sheet stack is from 42 N/mm.sup.2 to 94 N/mm.sup.2.

A binding device includes a first pushing member that includes protrusions along one direction and that pushes a recording-material bundle as a result of pushing the protrusions against one of surfaces of the recording-material bundle, the protrusions disposed side by side in a direction that intersects the one direction; and a second pushing member that includes protrusions along the one direction and that pushes the recording-material bundle as a result of pushing the protrusions against the other surface of the recording-material bundle, the protrusions disposed side by side in the direction that intersects the one direction, wherein, in at least one end portion in the one direction of each protrusion of at least one of the first pushing member and the second pushing member, a hollow is disposed in a top portion of each protrusion.