Sheet stacking device and image forming system including same

A sheet stacking device comprising:

• a pair of first sheet stackers configured to stack both end portions of a sheet to be ejected, the end portions being end portions of the sheet in a direction orthogonal to an ejecting direction of the sheet;
• a pair of sheet alignment members configured to contact both ends of the sheet in the direction orthogonal to the ejecting direction of the sheet to align the sheet on the pair of first sheet stackers;
• a second sheet stacker disposed lower than the pair of first sheet stackers and configured to stack the sheet dropped from between the pair of first sheet stackers;
• a sheet removal portion disposed on one side in the direction orthogonal to the ejecting direction of the sheet and configured to provide access to the sheet to facilitate removal of the sheet;
• and
• control circuitry configured to,
• cause one first sheet stacker of the pair of first sheet stackers and one sheet alignment member of the pair of sheet alignment members to move toward an opposite side of the sheet removal portion in the direction orthogonal to the ejecting direction of the sheet after the sheet is dropped from between the pair of first sheet stackers, and
• cause the one first sheet stacker and the one sheet alignment member not to move when there is a sheet to be continuously conveyed after the sheet is dropped.