A conveyorized oven that provides uniform cooking with control of the heater andor the conveyor belt speed. A fixing body is arranged on a housing part, which together with an opposite fixing body on the other housing part, form a fixed bearing for the drive shaft, each fixing body further having a recess forming a bearing seat for a bearing of the drive shaft. A housing of the ink tank is composed of a transparent resin. The zone separators may each have an angled surface which are positioned so that a sphere may be rolled toward the angled surface of the zone separator, roll over the zone separator and into a zone area. The management apparatus determines a transmission schedule for each of a plurality of the managed groups so that department counter information is transmitted from the image forming apparatuses belonging to each group at intervals of at least a first time period.