Patent ID: 6176480
Filing Date: 2001-01-23
Classification: B65H

Abstract:
An apparatus for stacking discharged sheets on a sheet stacking plate, comprising:a drive device for shifting the sheet stacking plate in an up-and-down direction;a distance sensor of a non-contact type disposed above said sheet stacking plate, and having a light illumination portion illuminating the sheet stacking plate with illumination light and a light receiving portion for receiving reflected light; anda control device for determining the distance between said distance sensor and a sheet stack resting on the sheet stacking plate, for determining a sheet stacking condition of the sheet stacking plate on the basis of the determined distance, and for controlling a driving of said drive device to shift the sheet stacking plate on the basis of the sheet stacking condition,wherein said control device determines that an upper surface of the sheet stacked on the sheet stacking plate reaches to a height position which is predetermined when the distance becomes shorter than a first predetermined distance, to thereby drive said drive device to lower the sheet stacking plate.