Sheet processing apparatus comprising binding and regulating members, and image forming apparatus comprising same

A sheet processing apparatus comprising:

• a pair of binding members that respectively have a pair of crimping teeth facing each other, which move between binding positions where a sheet bundle is bound and retreat positions retreated from the binding positions;
• and
• a pair of regulating members that are arranged close to the binding members and respectively have a pair of regulating pieces which face each other and move between regulating positions where displacement of the sheet bundle bound by the pair of crimping teeth is regulated and retreat positions retreated from the regulating positions,
• wherein when the pair of crimping teeth and the pair of regulating pieces are moved to their retreat positions, the pair of regulating pieces are held at the regulating positions until a separation distance between the pair of crimping teeth reaches a predetermined separation distance, and
• wherein the pair of binding members and the pair of regulating members are provided to be able to move independently from each other.