Patent ID: 8333372

Claim:
A sheet processing apparatus that forms asperity on a sheet bundle, which includes plural sheets, so as to bind the sheet bundle, comprising: a pair of rotating members having concave and convex portions on the outer periphery, wherein each of the pair of the rotating members has a first concave portion and a first convex portion and a second concave portion and a second convex portion, wherein a depth between the first concave portion and the first convex portion is different from a depth between the second concave portion and the second convex portions, and wherein the concave and convex portions of each of the pair of the rotating members, having the same depth, are meshed with each other to bind the sheet bundle; a moving portion that moves at least one of the pair of the rotating members so as to nip the sheet bundle by the pair of the rotating members or release the sheet bundle; and a controlling portion that controls the moving portion to allow the pair of rotating members to rotate with a concave portion of one rotating member and a convex portion of an other rotating member to mesh with each other while nipping the sheet bundle or releasing the sheet bundle.