Patent ID: 7874551

Claim:
A finisher comprising: a conveying unit configured to receive a plurality of sheets provided from outside of the finisher and convey the plurality of sheets; a holding unit configured to sequentially collect the plurality of sheets conveyed by the conveying unit to form a first sheet bundle; a support unit configured to receive the first sheet bundle; a stapling unit configured to staple the first sheet bundle on the support unit; a discharge unit configured to discharge the first sheet bundle stapled by the stapling unit from the support unit; and a control unit configured: to control the holding unit to form a part of a second sheet bundle subsequent to the first sheet bundle until the discharge unit discharges the first sheet bundle, to control the holding unit to receive a sheet of the first sheet bundle and the subsequent sheet of the first sheet bundle within a first period, to control the holding unit to receive the last sheet of the first sheet bundle and a first sheet of the second sheet bundle within a second period as same length as the first period, and to control the holding unit to receive a sheet of the second sheet bundle and the subsequent sheet of the second sheet bundle within a third period that is equal to the first and second periods in time length if the discharge unit has discharged the first sheet bundle and is different from the first and second periods in time length if the discharge unit has not discharged the first sheet bundle.