Patent ID: 9580267
Date: 2017-02-28
CPC Classifications: B65H,G03G

Claim:
1. A sheet discharge device comprising: a sheet discharge section configured to discharge a set of paper sheets through a sheet output port; a stapler configured to, before the set of paper sheets is discharged through the sheet output port, apply a staple to a predetermined location on a trailing end portion of the set of paper sheets in a direction of discharge thereof; a piling section capable of being piled with sets of paper sheets discharged through the sheet output port, while a pile of the sets of paper sheets on the piling section being inclined so that a trailing end of the pile of the sets of paper sheets in the direction of discharge is located below a leading end thereof in the direction of discharge; a lifting section configured to vertically lift and lower the piling section toward and away from the sheet output port; a top surface detecting section configured to detect that a trailing end, in the direction of discharge, of a top surface of the pile of the sets of paper sheets on the piling section capable of being lifted and lowered by the lifting section has reached a predetermined sheet receiving height; a discharge detecting section configured to detect that the set of paper sheets has been discharged through the sheet output port to the piling section; a control section configured to, when the discharge detecting section detects that the set of paper sheets has been discharged to the piling section, allow the lifting section to lower the piling section by a certain amount and then lift the piling section from a lowered position where the piling section lowered by the certain amount is located to a position where the trailing end, in the direction of discharge, of the top surface of the pile of the sets of paper sheets on the piling section is detected by the top surface detecting section; and a pile thickness calculating section configured to calculate, from a type and the number of paper sheets constituting each of the sets of paper sheets discharged through the sheet output port and the number of the discharged sets of paper sheets, a thickness of the pile, at the leading end thereof in the direction of discharge, of the sets of paper sheets on the piling section, calculate a thickness of the pile, at the trailing end thereof in the direction of discharge, of the sets of paper sheets on the piling section from an amount of movement of the piling section from the lowered position to the position where the trailing end of the top surface of the pile in the direction of discharge is detected by the top surface detecting section, and calculate an angle of inclination of the uppermost of the sets of paper sheets piled on the piling section with respect to a horizontal plane from the calculated thicknesses of the pile, at the leading and trailing ends in the direction of discharge, of the sets of paper sheets on the piling section, a height of inclination of the piling section, and a length of the paper sheets constituting the pile of the sets of paper sheets, wherein the control section is further configured to control the sheet discharge section to change a manner of discharging a subsequent set of paper sheets according to the calculated angle of inclination.