Patent ID: 8768238

Claim:
An image forming apparatus which is connectable to a sheet post processing device capable of changing a conveying speed when the sheet post processing device receives a sheet, the image forming apparatus comprising: an image forming unit configured to form an image on a sheet based on an input print job; a reversing unit configured to reverse front and back surfaces of a sheet on which an image is formed; a discharging unit configured to discharge a sheet in one of a reverse discharge mode and a non-reverse discharge mode, wherein the reverse discharge mode is a mode for discharging a sheet after front and back surfaces of the sheet are reversed by the reversing unit, and the non-reverse discharge mode is a mode for discharging a sheet, front and back surfaces of which are not reversed; and a control unit configured to control the discharging unit, while the image forming apparatus is not connected to the sheet post processing device, to discharge a sheet at a first speed in response to the sheet being discharged in the reverse discharge mode and to discharge a sheet at a second speed lower than the first speed in response to the sheet being discharged in the non-reverse discharge mode, and configured to control the discharging unit, while the image forming apparatus is connected to the sheet post processing device, to discharge a subsequent sheet, immediately subsequent to a previous sheet, at the first speed in the non-reverse discharge mode to the sheet post processing device in response to the previous sheet being discharged at the first speed and the subsequent sheet being discharged in the non-reverse discharge mode, and to discharge the subsequent sheet at the second speed in the reverse discharge mode to the sheet post processing device in response to the previous sheet being discharged at the second speed and the subsequent sheet being discharged in the reverse discharge mode.