An example device includes: a print engine including a fuser; an ambient temperature sensor; a memory storing a plurality of curves that relate, for given respective ambient temperatures, respective time periods for the fuser to heat to a fusing temperature, to respective factors associated with cooling of the fuser; and a processor The processor is to: detect a current ambient temperature using the ambient temperature sensor; select a curve, from the plurality of curves, using the current ambient temperature; determine a current factor associated with cooling of the fuser; and control the fuser to heat to the fusing temperature based on a respective time period determined from the curve and the current factor associated with cooling of the fuser.

An image forming apparatus includes a control unit configured to, in executing a job to form images continuously on a plurality of sheets of a recording material, accumulate an addition amount per sheet to an index in accordance with a number of sheets of the recording material to which images are formed in the job. A value of the addition amount per sheet is determined in correspondence with an attribute of the recording material used in the job. The control unit is configured to, during execution of the job, change a throughput of the job so that images are formed at a first throughput if an accumulated value of the index still does not exceed a predetermined threshold value and images are formed at a second throughput slower than the first throughput if the accumulated value of the index has exceeded the threshold value.

An image forming system includes: an image forming device that is disposed at a first conveyance path and forms an image on a recording medium that is a continuous sheet or a long sheet; a first conveyor that conveys the recording medium on the first conveyance path in a conveyance direction; an image reader that reads the image formed on the recording medium at a second conveyance path on a downstream side of the first conveyance path in the conveyance direction; a second conveyor that conveys the recording medium on the second conveyance path; and a controller that controls a speed of a drive source of the first conveyor and controls a torque of a drive source of the second conveyor.

An image forming apparatus includes a rotatable photosensitive member, a charging member, a developing device, a blade, a detecting portion, and a controller. The controller causes the photosensitive member to rotate through one full circumference or more on the following conditions during a predetermined operation: (i) a voltage which is a discharge start voltage or more is applied to the charging member, and (ii) an operation condition of the developing device is a first condition on which an amount of fog toner deposited from the developer carrying member on the photosensitive member is smaller than an amount of the fog toner on a second condition which is an operation condition of the developing device during a sheet interval before the image formation during the continuous image formation is interrupted.

A rotating member control device that controls a first rotating member and a second rotating member to convey a sheet includes a processor configured to execute a program to implement processes of controlling the first rotating member and the second rotating member to come into contact or be separated from each other and acquiring a value that corresponds to or is proportional to a driving torque of a first driving unit that rotationally drives the first rotating member. The processor acquires the value upon separation when the first rotating member and the second rotating member are separated from each other and upon conveyance when the sheet is held between and conveyed by the first rotating member and the second rotating member. The processor further sets a rotational speed of the second rotating member such that the value acquired upon separation and the value acquired upon conveyance become equal.

An image forming apparatus includes image bearers, motors, a reference position detector, and processing circuitry. The circuitry senses a density of a toner image on each bearer; forms an image pattern and senses, based on a detection result of the detector and a sensing result of the density, density unevenness in a rotation cycle and a phase of the density unevenness with respect to a rotational position reference of each bearer; calculates a target phase based on the phase sensed; calculates a relative phase difference based on a rotational position and the target phase of each bearer; selects, as a reference image bearer, an image bearer having a minimum phase correction value, based on a calculation result of the difference; and controls the rotational position of each of the other image bearers with respect to the reference image bearer to the phase correction value, with the motors being driven.

A control unit performs control to make a direction of an electric field generated in a first area of an image carrier forming a transfer portion during image forming operation, relative to a voltage applied to a brush member in a state where the first area passes through a contact portion, different from a direction of an electric field generated in a second area of the image carrier forming the contact portion, relative to the voltage applied to the brush member during a period when operation is shifted from first operation in which the image carrier is rotated at a first speed to second operation in which the image carrier is rotated at a second speed different from the first speed, during non-image forming operation different from the image forming operation.

A transmission unit transmits driving force to be supplied from a motor to a roller pair. A switching unit acts on the transmission unit to switch a rotation direction of the roller pair by the driving force between a normal rotation and a reverse rotation. A control unit controls a rotation speed of the motor to convey the sheet at a second conveyance speed in a part of a first time period. The second conveyance speed is lower than a first conveyance speed. The first conveyance speed is a conveyance speed when the sheet is conveyed in the image forming unit. In the first time period the sheet having the image formed on the first surface is conveyed in a first direction. In a second time period the sheet is conveyed in a second direction.

The image forming apparatus includes a control unit for converting image information into an image signal and output the image signal with reference to a timing signal, a sheet feeding control unit for feeding a recording material, an image forming unit for forming the image on a photosensitive drum based on the image signal output from the control unit, a transmission unit for transmitting a length of the image corresponding to a length of an output period of the image signal, an automatic sheet length detection mechanism for acquiring a length of the recording material in a conveyance direction thereof, and an image control unit for controlling a time interval at which the timing signal is output based on the size of the image and the size of the recording material.

A control unit performs control to make a direction of an electric field generated in a first area of an image carrier forming a transfer portion during image forming operation, relative to a voltage applied to a brush member in a state where the first area passes through a contact portion, different from a direction of an electric field generated in a second area of the image carrier forming the contact portion, relative to the voltage applied to the brush member during a period when operation is shifted from first operation in which the image carrier is rotated at a first speed to second operation in which the image carrier is rotated at a second speed different from the first speed, during non-image forming operation different from the image forming operation.