Patent ID: 8033543
Filing Date: 2011-10-11
Classification: B65H

Abstract:
1. A sheet stacking apparatus, comprising: a tray on which sheets are stacked; an aligning member which aligns sheets, wherein the aligning member aligns the sheets stacked on sheets previously stacked on the tray with a displacement in an aligning direction of the aligning member with respect to the sheets previously stacked; a moving unit which moves the tray so that the tray is lowered with an increase in the number of the stacked sheets; a support unit which supports the aligning member so that the aligning member is lowered within a predetermined distance with the aligning member being in contact with a top surface of the sheets previously stacked as the tray is lowered by the moving unit; and a changing unit which changes the aligning operation of the aligning member between a first state in which the aligning member is in contact with the top surface of the sheets previously stacked and a second state in which the number of the sheets stacked on the sheets previously stacked exceeds a predetermined number, the aligning member being spaced away from the top surface of the sheets previously stacked when the number of the sheets stacked on the sheets previously stacked exceeds the predetermined number, wherein the aligning member performs the aligning operation every time a first number of sheets are stacked on the tray in the first state, the aligning member performs the aligning operation every time a second number of sheets are stacked on the tray in the second state, and the first number is larger than the second number.