Sheet processing apparatus and image forming apparatus

摘要

A sheet processing apparatus for covering a sheet bundle with a cover sheet includes a creasing unit (218) for making a crease along an end portion of the cover sheet adjacent the edge of the sheet bundle opposite the spine edge of the sheet bundle. The sheet processing apparatus further includes a folding-back unit (220, 221) for folding-back the end portion of the cover sheet along the crease made by the creasing unit.