An imaging system includes an endless belt, a tensioning system that applies tension to the endless belt, a contact member that engages with the endless belt, and a detector that detects slack at a part of the endless belt. A controller causes the contact member to be separated from the endless belt so that the tensioning system reduces the slack of the endless belt in response to the detector detecting the slack.

An image forming apparatus includes a photosensitive member, an intermediate transfer member, a moving member, a driving motor, a stepper motor, a detector, a phase determiner, and a controller. The stepper motor drives the moving member to move between a first position at which the photosensitive member contacts the intermediate transfer member and a second position at which the photosensitive member contacts the intermediate transfer member are separated. The controller includes a first control mode to control a motor based on a predetermined current magnitude and a second control mode to control a motor by vector control. The controller starts driving the driving motor in the first control mode, and then switches from the first control mode to the second control mode. The controller controls the stepper motor in the first control mode during a period from when the stepper motor is activated to when the stepper motor is stopped.

An imaging system includes a belt roller, an endless belt, a steering member, a tilting mechanism, and a link mechanism. The endless belt rotates about the belt roller which extends in a longitudinal direction. The steering member is located inside the endless belt. The tilting mechanism is operably coupled to a center portion of the steering member. The link mechanism is operably coupled to the tilting mechanism and operates the tilting mechanism so that the steering member is tilted in response to a displacement of the endless belt in the longitudinal direction of the belt roller.

An image forming apparatus includes a photosensitive member, a transfer unit having a transfer belt, a primary transfer roller, a secondary transfer inner roller below the primary transfer roller in a vertical direction, and a stretching roller, a secondary transfer outer roller, a support unit, and an air duct provided in the transfer unit. The secondary transfer outer roller faces the secondary transfer inner roller via the transfer belt and forms a nip portion for secondarily transferring a toner image on the transfer belt to a sheet. The air duct is located downstream of the nip portion in a sheet conveyance direction and below a portion of the transfer belt stretched between the secondary transfer inner roller and the stretching roller in the vertical direction. The air duct includes an air intake port and moves with the transfer unit with movement of the transfer unit from the support unit.

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 imaging system includes a belt roller, an endless belt, a steering member, a tilting mechanism, and a link mechanism. The endless belt rotates about the first belt roller which extends in a longitudinal direction. The steering member is located inside the endless belt. The tilting mechanism is operably coupled to a center portion of the steering member. The link mechanism is operably coupled to the tilting mechanism and operates the tilting mechanism so that the steering member is tilted in response to a displacement of the endless belt in the longitudinal direction of the first belt roller.

A cam driver includes a support, a cam, a motor, and a retracting torque applicator. The support supports an object. The cam moves the support. The motor rotates the cam and maintains a position of the cam. The retracting torque applicator applies torque to the cam in a direction to move the object away from a counter object that faces the object.

In an image-forming apparatus, a controller is configured to perform: in a case where the controller performs forming a multicolor image on a sheet: bringing, in response to a temperature of a fixing device reaching a first temperature lower than a fixing temperature, first and second developing rollers into contact with first and second photosensitive drums; and feeding, after a first period of time elapses from a time when the temperature of the fixing device reaches the first temperature, a sheet from a sheet tray toward the belt using a pickup roller. The controller is configured to further perform: in a case where the controller performs forming a single-color image on the sheet: bringing, after a second period of time elapses from the time when the temperature of the fixing device reaches the first temperature, the second developing roller into contact with the second photosensitive drum; and the feeding.

An image forming apparatus includes a plurality of photosensitive drums, an intermediate transfer belt, a cleaning member to contact an inner surface of the intermediate transfer belt to remove impurities from the intermediate transfer belt, a storage member including a storage to accommodate the impurities removed by the cleaning member, and a shutter movable to a first location at which the storage is opened and a closing location at which the storage is closed.

An image forming apparatus includes an image bearing member, a belt, a contact member, a rotation shaft member, a cam, an opposing member, and a damper. The belt receives a toner image from the image bearing member. The cam rotates in tandem with the rotation shaft member and contacts or separates the contact member and the belt. The opposing member is disposed to face the rotation shaft member in a direction intersecting with a rotation shaft member shaft direction. The damper member has a first flexible portion and a second flexible portion that are elastically deformable by contacting with the opposing member. In either contact operation or separation operation of the contact member to/from the belt, the damper member rotates in tandem with rotation of the rotation shaft member so that both the first flexible portion and the second flexible portion contact with the opposing member and are elastically deformed.