Patent ID: 7556263

Claim:
A paper stacking apparatus stacking fed papers, comprising: a paper inlet to which said fed paper enters; a stacking and accommodating portion stacking the papers entering from said inlet; a movable push plate installed within said stacking and accommodating portion; and a control portion controlling a position of said push plate, wherein said stacking and accommodating portion is sloped in such a manner as to be lower in accordance with being away from said paper inlet, wherein said stacking and accommodating portion is provided with a leading end detecting means for detecting a position of a leading end surface of the papers stacked in said stacking and accommodating portion by detecting position of said stack guide, wherein the paper stacking apparatus further comprises a memory means for storing a stack number count information corresponding to the number of the papers accommodated and stacked in said stacking and accommodating portion, and a thickness information per one of said papers, wherein said control portion detects a stack width of the stacked papers on the basis of the count information and the thickness information per one paper stored in said memory means, wherein said control portion calculates a stack width of the papers stacking in said stacking and accommodating portion, on the basis of a product of the count information and the thickness information per one paper stored in said memory means, and wherein said control portion calculates a moving distance of said push plate and executes a control of moving said push plate by subtracting said stack width from the accommodation width of said stacking and accommodating portion.