Sheet alignment device for a copying apparatus having an intermediate standby position

摘要

A sheet alignment device to align the edges of recording sheets stacked on a sheet stacker of a duplex unit in a two-sided copying apparatus, in which a document image has been copied onto the first surface of the recording sheet and the recording sheet is reversed so that another document image can be copied onto the second surface of the recording sheet. The device has an edge pushing member which can be driven in the range from the maximum width to the minimum width of the recording sheets used in the apparatus in order to align the edges of the recording sheets, a driver which moves the edge pushing member in the width direction of the recording sheet, a detector which detects the width of the edge pushing member located in a home position, and a controller which controls the movement of the edge pushing member to the home position being narrower than the maximum size of recording sheet and wider than the minimum size, based on the result of the detection.