Patent ID: 8033539
Filing Date: 2011-10-11
Classification: B65H

Abstract:
1. A sheet post process device with a stapler mechanism, the sheet post process device comprising: a conveying path configured to convey a sheet on which an image is formed to the stapler mechanism; a first sensor disposed along the conveying path and configured to detect a moving position of the sheet; a tray in which plural of the sheets are stacked to undergo a stapling process; and a cam disposed at a conveying path outlet through which the sheet is ejected from the conveying path to the tray, the cam having a spiral shape and being rotatable, wherein when the sheet has passed through the conveying path outlet and is freely falling, the cam rotates and comes into contact with the sheet to forcibly push the sheet down to the tray, so that so that the sheet is stacked in the tray within a prescribed length of time; a second sensor disposed on a rotary shaft of the cam and configured to detect a phase of the cam, wherein the cam has an Archimedean spiral shape, and the cam is controlled to move and stop based on information from the first sensor and information from the second sensor; and a torque restricting device connected to the rotary shaft of the cam, wherein in the event that more than a prescribed number of the sheets are stacked in the tray, the cam interferes with a stacked batch of the sheets, and the rotary shaft idly rotates.