Sheet post-process apparatus

A sheet loading method, comprising:

• conveying sheets along a sheet conveying direction via a pair of waiting tray parts which support the sheets, the waiting tray parts arranged at an interval in a transverse direction orthogonal to the sheet conveying direction;
• applying, via a strike down member, a downward force on the sheets to make the sheets bend and fall down from the pair of waiting tray parts;
• retaining, via a distal end upper face retainer, a distal end upper face of the sheets on the pair of waiting tray parts when the interval widens from a first width smaller than a width of the sheets orthogonal to the sheet conveying direction for loading the sheets to a second width larger than the width of the sheets;
• allocating a rotary shaft in association with the distal end face in the sheet conveying direction;
• rotating the distal end upper face retainer and the strike down member coaxially with a rotary shaft, that is mounted coaxially therewith, when the sheet discharger is projected on a horizontal plane, a discharge direction of the sheet discharger being parallel to the sheet conveying direction;
• receiving, via a receiving tray, the sheets fallen from the pair of waiting tray parts;
• and
• discharging, via a sheet discharger, a bundle of sheets to which a post-process has been performed, from the receiving tray.