Sheet stacking device, post processing apparatus and image forming apparatus

Abstract

A sheet stacking device includes a housing, a discharge tray, a lifting mechanism, a first upper surface detection part, a second upper surface detection part and a control part. The housing has a discharge port. On the discharge tray, the sheet discharged from the discharge port in a predetermined discharge direction is stacked. The lifting mechanism supports the discharge tray. The first upper surface detection part detects a first detected surface of the sheet on the discharge tray. The second upper surface detection part detects a second detected surface of the sheet on the discharge tray on a downstream side of the first detected surface in the sheet discharge direction. The control part controls the lifting mechanism based on a detection result of the first upper surface detection part and a detection result of the second upper surface detection part, and adjusts the discharge tray at a predetermined height.

Dependencies are inferred from the claim text.