An image forming apparatus includes: a drum unit; a fixing unit including a fixing member and a pressing member; a fixing pressure release unit disposed below the fixing unit; a body frame including a lateral support plate and a partition plate; a cooling fan; a first cooling duct; and a shifting mechanism. The first cooling duct is provided on an outside of the lateral support plate. The lateral support plate is provided with an air outlet. The fixing pressure release unit includes a nip pressure adjustment gear and a rotary gear. The fixing unit performs a switching behavior of switching a state of the fixing member and the pressing member between a pressed state and a released state by a rotary drive force supplied from the rotary gear to the nip pressure adjustment gear. The shifting mechanism shifts the fixing unit vertically upward in conjunction with the switching behavior.

An image forming apparatus includes a transfer device, a fixing device including a fixing belt, a heat source, a pressure roller, and a pressure roller temperature detector, a storage that stores, for each thermal expansion degree in a radial direction of the pressure roller, tables each showing a correspondence between a surface temperature of the pressure roller and an appropriate circumferential speed of the pressure roller, and a processor that acquires, at a start of a printing job, a table from the storage, based on a temperature difference between a surface temperature of the fixing belt and the surface temperature of the pressure roller, refers to the table being acquired to decide the circumferential speed of the pressure roller that corresponds to the surface temperature of the pressure roller.

An image forming apparatus performs an inter-material control in a case where a developed image satisfying a condition for executing the inter-material control will be formed on a material. The condition is that a ratio of an area of the developed image that is formed in a third region to an area of the third region exceeds a threshold. The third region is a region between a first region and a second region. The first region and the second region are, respectively, a region that is downstream of a nipped region and a region that is upstream of the nipped region.

An image forming apparatus includes a conveyance member to convey a sheet, an image forming unit, a fixing device, a component, and a controller. The image forming unit forms a toner image on the conveyed sheet conveyed. The fixing device fixes an unfixed toner image formed on the sheet, onto the sheet. Heat of the fixing device propagates to the component. The controller controls a passing sheet interval between a plurality of sheets passing through the fixing device. The controller executes throughput control for controlling a sheet interval, which is an interval between a preceding sheet and a subsequent sheet passing through the fixing device, such that a temperature of a non-passage region through which sheets do not pass in the fixing device is suppressed to a predetermined first limit temperature or less and a temperature of the component is suppressed to a predetermined second limit temperature or less.