Patent ID: 8215627

Claim:
A sheet processing apparatus that performs bookbinding process on a folded sheet bundle, comprising: a holding portion configured to hold the folded sheet bundle; and a pressing member configured to press a folded spinal portion of the folded sheet bundle to deform the folded spinal portion into a square shape, the pressing member including a plurality of separate pressing members arranged in a direction along a folding line of the folded spinal portion; and a controller configured to control the pressing member and the holding portion, so that at least one of the pressing member and the holding portion can move in a direction perpendicular to a folding line of the folded spinal portion of the folded sheet bundle held by the holding portion so that the pressing member approaches the folding line of the folded spinal portion to press the folded spinal portion, and so that an operation for pressing the folded spinal portion is successively performed from a separated pressing member positioned on a center of the folded spinal portion to a separated pressing member positioned on both ends of the folded spinal portion in the direction along the folding line of the folded spinal portion.