Provided is an image forming apparatus, in which a recording material is conveyed by a reverse portion rotated in a first direction at a first velocity which is faster than a conveyance velocity of the recording material in a fixing portion after a rear end portion of the recording material passes through the fixing portion, and then, the recording material is conveyed to a conveying portion by the reverse portion rotated in a second direction opposite to the first direction through a conveyance path at a second velocity which is faster than the conveyance velocity of the recording material in the fixing portion, and a conveyance velocity of the recording material is set to a third velocity which is slower than the second velocity at a predetermined timing before the rear end portion of the recording material reaches a curved portion of the conveyance path.

In an image forming device, a photosensitive drum forms an image on a sheet based on the image formation data. The roller conveys the sheet. A motor provides the roller with driving force to rotate the roller. A controller acquires an advance command which is received from the external terminal prior to reception of the image formation data. The advance command includes option information. The controller determines a rotational speed of the roller based on the option information. The rotational speed is determined to be changeable depending on the optional information. The controller performs a preliminary process before the photosensitive drum forms an image on the sheet based on the image formation data. The preliminary process is to control the motor so that the roller rotates at the rotational speed determined in the determining

An image forming apparatus includes a fixing member and a pressing member forming a fixing nip therebetween, a heat generator, and a processor. The heat generator is disposed to heat a print medium passing through the fixing nip via the fixing member. The processor is configured to control the heat generator to start heating at a timing when a non-fixed image portion formed on the print medium is expected to reach the fixing nip, based on image data of an image to be fixed, a conveyance speed of the print medium, and an estimated heat capacity of the print medium.

An image forming apparatus includes an image forming part, a fixing device, a fixing temperature sensor, a drive device, a printed sheet number counting part, a fixing voltage power supply, a controller, and an apparatus external temperature sensor. The controller can perform a cooling mode in which, when a number of continuous printed sheets at a reference speed exceeds an upper limit number, a number of printed sheets per unit time is gradually decreased to suppress an increase of an apparatus internal temperature. The controller sets the upper limit number based on a temperature difference between the fixing temperature detected by the fixing temperature sensor and the apparatus external temperature detected by the apparatus external temperature sensor.

An image forming apparatus includes a transfer unit for transferring a toner image onto a sheet, a fixing device for fixing the image, the fixing device including a belt, a pressure element for pressing against the belt, a heating member on the belt including a heat generating element and electrodes on both sides of the heat element in a sheet conveyance direction and connected to the heat element, and an adjustment mechanism for moving one of the heating member and the pressure element in a manner to move the one closer to or away from the other, and a controller for controlling the adjustment mechanism so that a distance between the heating member and the pressure element becomes a first distance during a fixing process and a second distance larger than the first distance during temperature raising of the heating member, which is conducted before the fixing process.

According to an embodiment, an image forming apparatus measures a temperature of a pressing member and controls heat generation of a heater such that the measured temperature approaches a control temperature. Further, the image forming apparatus sets, before starting image formation of one job including image formation, one candidate temperature of a plurality of predetermined candidate temperatures different from each other as the control temperature on the basis of the number of sheets to be used and a sheet size to be used in the image formation of the one job.

An image forming apparatus includes a transfer unit for transferring a toner image onto a sheet, a fixing device for fixing the image, the fixing device including a heating member including a heat generating element and electrodes on both sides of the heat generating element in a sheet conveyance direction and connected to the heat generating element, and a pressure element for pressing against the heating member, and a controller for controlling an adjustment mechanism so that a distance between the heating member and the pressure element becomes a first distance during a fixing process and a second distance larger than the first distance during temperature raising of the heating member, which is conducted before the fixing process.

An image forming apparatus includes a motor, an image formation-transfer section, a switching mechanism, a fixing section, and a controller. The motor generates driving force. The image formation-transfer section state-changes between a first contact state and a first separate state by the driving force. The switching mechanism transmits and cuts off the driving force to the image formation-transfer section. The fixing section includes first and second rotating members, and state-changes between a second contact state and a second separate state by the driving force. The controller controls the motor and the switching mechanism and thereby causes part or all of a first period, in which the fixing section state-changes from the second separate state to the second contact state, and part or all of a second period, in which the image formation-transfer section state-changes from the first separate state to the first contact state, to overlap each other.

An image forming apparatus includes an image bearing member, a transfer portion, a fixing portion, a first sheet feeding portion including a first belt portion for forming a first feeding surface, a second sheet feeding portion including a second belt portion for forming a second feeding surface, a height detecting portion for outputting a signal depending on a height of a sheet from the first feeding surface at a detecting position, and a controller for receiving the signal outputted from the height detecting portion and for controlling the fixing portion.

An image forming apparatus includes: a transferer that transfers a toner image on an image carrier formed by an image former onto a paper sheet; a fixer that heats and thereby fixes the toner image on the paper sheet; a read image acquisitor that acquires read image data of the paper sheet on a downstream side of the fixer in a conveyance direction, the read image data being generated by a reader that reads an image of the paper sheet; and a hardware processor that: controls a conveyance speed of the paper sheet in the transferer and/or the fixer, and changes or updates the conveyance speed based on an image of the acquired read image data.