Patent ID: 8240654

Claim:
A spine formation device comprising: a sheet conveyer that conveys a bundle of folded sheets with a folded portion of the bundle of folded sheets forming a front end portion of the bundle of folded sheets; a sandwiching member disposed downstream from the sheet conveyer in a sheet conveyance direction in which the sheet conveyer conveys the bundle of folded sheets, the sandwiching member to sandwich and squeeze the bundle of folded sheets, in a direction of thickness of the bundle of folded sheets; and a spine formation unit disposed downstream from the sandwiching member in the sheet conveyance direction, to flatten the folded portion of the bundle of folded sheets held by the sandwiching member, the folded portion of the bundle of folded sheets projecting a predetermined length from the sandwiching member in the sheet conveyance direction, the spine formation unit pressing against the folded portion of the bundle of folded sheets in a reverse direction of the sheet conveyance direction while moving in a direction perpendicular to both the sheet conveyance direction and a longitudinal direction of the folded portion of the bundle of folded sheets.