Sheet aligning device, sheet processing device, image processing apparatus

A sheet aligning device that has an inclined tray held by a frame and aligns a plurality of sheets conveyed onto the inclined tray, the sheet aligning device comprising:

• a support member projected on the inclined tray, supported so as to be movable on the inclined tray, having a support surface that abuts on leading ends of the sheets that are sequentially conveyed onto the inclined tray, the support member configured to support, at a predetermined reference position, the leading ends of the sheets;
• a support member moving mechanism configured to move the support member along the inclined tray;
• a regulation member, projected from the support surface toward an upstream in a sheet entry direction in which the sheets enter onto the inclined tray, supported so as to be movable on the support surface in a separating direction from or an approaching direction to the inclined tray, and defining a sheet entry space in which the leading ends of the sheets enter;
• a regulation member moving mechanism configured to move the regulation member on the support surface;
• and
• a control unit configured to control the support member moving mechanism and the regulation member moving mechanism,
• the control unit controlling the regulation member moving mechanism each time a sheet is conveyed onto the inclined tray, to widen the sheet entry space by moving the regulation member in the separating direction from the inclined tray, and then to narrow the sheet entry space by moving the regulation member in the approaching direction to the inclined tray.