Sheet discharge apparatus and image forming apparatus

This invention relates to a sheet discharge control method, a sheet discharge apparatus and an image forming apparatus for stacking sheets with images formed thereon discharged from an image forming apparatus such as a copier or a printer. A sheet discharge apparatus of the present invention is equipped with a discharge device for discharging a sheet from an image forming apparatus, a storage device for storing the sheet discharged from the discharge device, an elevator device for raising and lowering the storage device relative to the discharge device, a position detection device for detecting a surface of the uppermost sheet stored in the storage device or a surface of the storage device to stack the sheet, a reception device for receiving a signal indicating a transport status in the image forming apparatus, and a control device for temporarily stopping the discharge device after the transported sheet is discharged to the storage means by the discharge means when the position detection device detects the uppermost surface of the uppermost sheet stored in the storage device or the surface of the storage means to stack the sheet is away from a predetermined position and the reception device detects the sheet transported in the image forming apparatus.