Patent ID: 8851468

Claim:
A sheet stacking apparatus, comprising: a sheet discharge portion configured to discharge a sheet; a sheet stacking portion on which the sheet discharged by the sheet discharge portion is stacked; an abutment portion against which an end portion of the sheet stacked on the stacking portion is abutted; a position detecting portion configured to detect a position of a top sheet, which is stacked on the stacking portion, in a height direction; a lowering portion configured to lower the stacking portion in accordance with a detection result obtained from the position detecting portion; a transporting portion provided above the stacking portion so as to be capable of raising and lowering, the transporting portion configured to come into contact with the sheet discharged by the sheet discharge portion to transport the sheet toward the abutment portion and bring the sheet into abutment with the abutment portion; a stacking amount detecting portion configured to detect a stacking amount of the sheet stacked on the stacking portion; and a control portion configured to perform control of a position of the transporting portion in the height direction where the transporting portion transports the sheet toward the abutment portion, in accordance with the stacking amount of the sheet stacked on the stacking portion which is detected by the stacking amount detecting portion.