An image forming apparatus includes an image forming unit, a sheet conveying unit, a TOD (Top of Data) control module for instructing the image forming unit to start generation of a toner image, a timing roller driving module for instructing the sheet conveying unit to start driving of the timing roller, an image synchronization module designed depending on the sheet conveying unit and the image forming unit, and a sheet information module for generating an image synchronization identifier for designating a pattern of image synchronization control related to printing of the toner image on the sheet, depending on a type of the sheet designated. The image synchronization module is activated when the formation of the toner image on the sheet has become possible, and activate each of the TOD control module and the timing roller driving module, with a relative time lag based on the image synchronization identifier.