An image forming apparatus includes a main housing, a drawer, and a cartridge. The drawer is movable between an inside position inside the main housing and an outside position outside the main housing. The cartridge is installable into and removable from the drawer. The cartridge includes a photosensitive drum configured to rotate about a drum axis. The drawer comprises a lock member movable between a lock position in which the drawer is locked to the main housing, and an unlock position in which the drawer is unlocked from the main housing. The cartridge installed in the drawer is rotatable about the drum axis between a first position and a second position. The lock member is positioned in the lock position when the cartridge is positioned in the first position, and positioned in the unlock position when the cartridge is positioned in the second position.

Provided is an image forming device capable of performing an operation corresponding to a defect occurring in a fixing device at a desired timing. The image forming device includes a conveyance unit, an image forming unit, a fixing device, a motor, and a control unit. The motor drives the fixing device and outputs a signal having a magnitude corresponding to a value of a drive current. The control unit, when conveyance of a print medium is stopped and when the motor is driven in a first operation mode, continues to drive the motor in the first operation mode, and performs a first operation when the magnitude of the signal is out of a first range, and when the conveyance of the print medium is stopped and when the motor is driven in a second operation mode, stops driving the motor in the second operation mode and then drives the motor in the first operation mode, and performs the first operation when the magnitude of the signal is out of the first range.

A sensor is located upstream of a conveyance roller in a sheet conveyance direction. A switch switches driving and stopping of a photosensitive drum. A controller performs a first mode process as a warm-up process of driving the conveyance roller and a fuser. The first mode process includes: driving the photosensitive drum for a particular time; in response to detecting a sheet within the particular time by the sensor, controlling the switch to continue driving the photosensitive drum after the particular time elapses and to discharge the detected sheet to a sheet discharge tray; and in response to not detecting the sheet within the particular time by the sensor, controlling the switch to stop driving the photosensitive drum at a time point when the particular time elapses, and driving the conveyance roller and the fuser to complete the warm-up process in a state where the photosensitive drum is stopped.

An image forming apparatus includes a photosensitive member; an exposure portion configured to expose the photosensitive member to light depending on image information to form a latent image on the photosensitive member; a developing portion configured to develop the latent image into a toner image with toner; and a transfer portion configured to transfer the toner image from the photosensitive member onto a recording material. The image forming apparatus changes a surface movement speed of the photosensitive member at timing prior to predetermined timing, when a moving speed of a recording material at the transfer portion changes, by a predetermined time.

An image forming apparatus including: a setting unit configured to set light intensity correction data stored in a storage unit according to an exposure position while a light beam is being scanned on a photosensitive member at a first scan speed; and a light intensity controller configured to control a light intensity based on the correction data set by the setting unit, wherein the setting unit calculates a light intensity correction data corresponding to a position between a plurality of positions based on the stored correction data, set the correction data according to the exposure position while the light beam is being scanned at a second scan speed lower than the first scan speed; and fixes a switching period for switching the correction data according to the exposure position while the light beam is being scanned on an image forming area of the photosensitive member regardless of the scan speed.

A positional relationship between a photosensitive drum and an intermediate transfer belt during a period from the start of the driving of the photosensitive drum to the start of image formation, or during a period of the end of the image formation to the stop of the driving of the photosensitive drum enters a separating state in a case where the image formation is executed when the process speed is a first speed, and enters a contacting state in a case where the image formation is executed when the process speed is a second speed.

A motor control apparatus includes: a switching power supply; a first motor configured to operate with a voltage from the switching power supply; and a control unit configured to control the first motor, wherein the control unit is further configured to cause the switching power supply to supply power of the switching power supply to a load other than the first motor before detecting an initial position of a rotor of the first motor using a current flowing through the first motor.

An image forming apparatus includes a photosensitive member; an exposure portion configured to expose the photosensitive member to light depending on image information to form a latent image on the photosensitive member; a developing portion configured to develop the latent image into a toner image with toner; and a transfer portion configured to transfer the toner image from the photosensitive member onto a recording material. The image forming apparatus changes a surface movement speed of the photosensitive member at timing prior to predetermined timing, when a moving speed of a recording material at the transfer portion changes, by a predetermined time.

An image forming apparatus includes: a density unevenness measurement mode processing portion that, in a density unevenness measurement process, detects density of a density unevenness measurement toner image, which has been formed in a rotational direction of the photoreceptor drum, multiple times in the rotational direction and captures in a memory portion all detected density information associating thereof with rotation phases of the photoreceptor drum; and an image quality adjustment processing portion that, in an image quality adjustment mode, detects density of an image quality adjustment toner image, which has been formed at any position in the rotational direction of the photoreceptor drum, in the rotational direction and corrects detected density information based on density information associated with a rotation phase matching a rotation phase where density of the image quality adjustment toner image has been detected among said all density information having been captured in the memory portion by the density unevenness measurement processing portion.

A method of controlling a printing apparatus, comprises printing an image on a sheet; measuring a printing speed of the printing; and storing, for each printing speed measured in the measuring, a number of sheets printed in the printing.