Patent ID: 9216876
Filing Date: 2015-12-22
Classification: B65H,G03G

Abstract:
1. A paper discharge device comprising: a paper receiving tray on which discharged paper sheets are stacked; an end fence configured to restrict leading end positions of the paper sheets discharged to the paper receiving tray; a lift mechanism configured to lower the paper receiving tray by a prescribed distance upon reach of a top surface position of the paper sheets stacked on the paper receiving tray to a reference position; an ultrasonic sensor configured to emit an ultrasonic wave in a horizontal direction toward the paper receiving tray from upstream of the paper receiving tray in a discharge direction of the paper sheets in a prescribed height range including the reference position and portions above and below the reference position, and to receive a reflected wave from a detection target; and a detector configured to detect the top surface position on a basis of changes in a reception level of the reflected wave over an elapsed time from an emission of the ultrasonic wave, wherein the detector is further configured to detect a distribution of positions of the detection target in the horizontal direction in the prescribed height range on a basis of the changes in the reception level of the reflected wave over the elapsed time from the emission of the ultrasonic wave, and determine whether a jam occurs in the paper sheets stacked on the paper receiving tray on a basis of the detected distribution.