Sheet post-processing apparatus and image forming apparatus

A sheet post-processing apparatus, comprising:

• a stapling unit configured to drive a staple into a plurality of stacked sheets;
• a movable table configured to rectilinearly move in unison with the stapling unit in a perpendicular direction perpendicular to a direction of conveyance of a sheet;
• a rectilinearly driving portion configured to rectilinearly move the movable table in the perpendicular direction,
• the rectilinearly driving portion causing the stapling unit to rectilinearly move through the movable table, such that the sheet post-processing apparatus performs tilted stapling with the stapling unit that drives the staple into the plurality of stacked sheets in a vicinity of a corner thereof in such a manner that the staple has a predetermined angle with respect to the direction of the conveyance of a sheet;
• a rotationally driving portion configured to cause the movable table to rotate such that the stapling unit is tilted so as to drive the staple at the predetermined angle with respect to the direction of the conveyance of a sheet;
• a tilt retention portion configured to mechanically hold the movable table such that the stapling unit maintains a tilted state;
• a base member;
• a guide groove that is disposed in the base member, including a perpendicular groove configured to extend along the perpendicular direction and a tilted groove configured to extend along a tilted direction tilted at the predetermined angle with respect to the direction of the conveyance of a sheet;
• a guide groove engagement portion that is disposed or extended along an extending direction of the guide groove and inserted in the guide groove such that the guide groove engagement portion is connected to the movable table on a side of the base member;
• a long hole that is disposed at the movable table on the side of the base member, including a long hole of a conveyance direction and a long hole of a tilting direction, the long hole of the conveyance direction extending in the direction of the conveyance of a sheet in a matched state where a direction in which the guide groove engagement portion is disposed or extends matches a direction in which the perpendicular groove of the guide groove extends, and the long hole of the tilting direction continuing from the long hole of the conveyance direction and extending at an angle with respect to the direction of the conveyance of a sheet in the matched state;
• and
• a long hole engagement portion inserted into the long hole, and configured to be movable in the perpendicular direction with respect to the base member;
• wherein
• the rectilinearly driving portion is configured by the guide groove engagement portion being inserted in the perpendicular groove and the long hole engagement portion being inserted in the long hole of the conveyance direction;
• the rotationally driving portion is configured by the guide groove engagement portion moving between the perpendicular groove and the tilted groove and the long hole engagement portion moving between the long hole of the conveyance direction and the long hole of the tilting direction;
• and
• the tilt retention portion is configured by the guide groove engagement portion being inserted in the tilted groove and the long hole engagement portion being inserted in the long hole of the tilting direction, when a direction in which the long hole of the tilting direction extends substantially matches the perpendicular direction.