Sheet stacking device and post-processing apparatus

A sheet stacking device comprising:

• a discharge port through which a sheet is discharged along a predetermined discharge direction;
• an alignment wall extending in an upper-and-lower direction below the discharge port;
• a discharge tray on which the sheet discharged through the discharge port is stacked and provided so as to be capable of moving up and down along the alignment wall;
• an alignment belt stretched along the alignment wall in the upper-and-lower direction so as to be able to circulate in the upper-and-lower direction, the alignment belt having an inner circumferential surface facing the alignment wall and an outer circumferential surface with which an upstream edge of the sheet stacked on the discharge tray in the discharge direction comes into contact, and circulating in the upper-and-lower direction at a same speed as the discharge tray in synchronization with the discharge tray;
• a guide part configured to be provided between the alignment wall and the alignment belt, the guide part with which the inner circumferential surface of the alignment belt slides in contact;
• and
• an elevating part configured to move up and down the discharge tray, wherein
• the elevating part includes:
• a drive shaft and a driven shaft disposed along a width direction perpendicular to the discharge direction and spaced apart from each other in the upper-and-lower direction;
• and
• a pair of lifting belts which supports the discharge tray and is stretched between the drive shaft and the driven shaft so as to be able to circulate in the upper-and-lower direction,
• the alignment belt includes a pair of alignment belts, and
• the pair of alignment belts is disposed between the pair of lifting belts at a predetermined interval in the width direction, and are stretched between the drive shaft and the driven shaft.

A sheet stacking device comprising:

• a discharge port through which a sheet is discharged along a predetermined discharge direction;
• an alignment wall extending in an upper-and-lower direction below the discharge port;
• a discharge tray on which the sheet discharged through the discharge port is stacked and provided so as to be capable of moving up and down along the alignment wall;
• an alignment belt stretched along the alignment wall in the upper-and-lower direction so as to be able to circulate in the upper-and-lower direction, the alignment belt having an inner circumferential surface facing the alignment wall and an outer circumferential surface with which an upstream edge of the sheet stacked on the discharge tray in the discharge direction comes into contact, and circulating in the upper-and-lower direction at a same speed as the discharge tray in synchronization with the discharge tray;
• and
• a guide part configured to be provided between the alignment wall and the alignment belt, the guide part with which the inner circumferential surface of the alignment belt slides in contact, wherein
• the alignment belt includes a pair of alignment belts, and
• the guide part is a flat plate-shaped member having a height equivalent to a lifting range of the discharge tray and a width larger than a distance between the pair of alignment belts.