An image forming apparatus includes an image bearing member and transfer and control units. The transfer unit and image bearing member form a nip portion where a recording material receives a toner image. The control unit controls image formation based on a timing when a recording material leading edge is detected. To perform sheet conveyance, the control unit changes a first recording material conveyance speed to a second speed before a fed first recording material leading edge is detected. Before the first recording material leading edge reaches the nip portion, the control unit changes the first recording material conveyance speed to a first speed, slower than the second speed, based on when the fed first recording material leading edge is detected. The control unit obtains a timing for the image formation to the image bearing member based on when the conveyance speed is changed from the faster to slower speed.

Provided is an image forming apparatus including an image carrier, a transfer unit, a driver, a hardware processor, an adjustment mechanism, and a speed detector. The hardware processor sets a command value. The hardware processor performs a constant-torque control based on a constant-speed drive torque detected in a constant-speed control. In the constant-torque control, the hardware processor performs a feedback control to set a reference value to an average speed of the driver during passage of a first sheet and calculate a difference from an average speed during passage of a subsequent sheet so as to derive the command value. The hardware processor determines whether a load torque increase, its factor, and/or its influence exceeds a threshold, and forcibly sets the reference value to a speed detected while a pressure between the transfer unit and the image carrier is reduced by the adjustment mechanism from the pressure during image transfer.

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 primary transfer roller is disposed upstream or downstream from the center of rotation of a photosensitive drum in the moving direction of an intermediate transfer belt. The primary transfer roller includes a core metal and an elastic layer coating the outer circumference of the core metal and having a thickness of less than 2.0 mm. The primary transfer roller has an Asker-C hardness of 40° or higher and 85° or lower.

An imaging system includes an image carrier, a charging device to form a toner image by charging a surface of the image carrier, a polishing roller, and a control device. A discharge product is generated on the surface of the image carrier as a result of charging the image carrier, and the polishing roller polishes the discharge product generated on the surface of the image carrier. The control device controls a polishing operation of the polishing roller in response to one or more detected characteristics.

A control device includes circuitry. The circuitry detects density unevenness of a toner image occurring according to a rotation cycle of a plurality of image bearers based on rotation phases and toner image density of the plurality of image bearers, controls rotation phases and rotation speeds of the plurality of image bearers, corrects the rotation phases and the rotation speeds of the plurality of image bearers, controls the rotation speeds of at least two of the plurality of image bearers to be a specified rotation speed, and starts a detection operation of the rotation phases of the plurality of image bearers after a difference between each of the rotation speeds of the at least two of the plurality of image bearers and the specified rotation speed falls within a specified range.

Provided is an image forming apparatus including an image carrier, a transfer unit, a driver, a hardware processor, an adjustment mechanism, and a speed detector. The hardware processor sets a command value. The hardware processor performs a constant-torque control based on a constant-speed drive torque detected in a constant-speed control. In the constant-torque control, the hardware processor performs a feedback control to set a reference value to an average speed of the driver during passage of a first sheet and calculate a difference from an average speed during passage of a subsequent sheet so as to derive the command value. The hardware processor determines whether a load torque increase, its factor, and/or its influence exceeds a threshold, and forcibly sets the reference value to a speed detected while a pressure between the transfer unit and the image carrier is reduced by the adjustment mechanism from the pressure during image transfer.

According to one embodiment, an image forming apparatus includes an image carrier, an exposing apparatus, a developing device, a transfer device, a fixing device, a history acquisition unit, an estimation unit, and an output unit. The exposing device exposes the image carrier to form an electrostatic latent image on the image carrier. The developing device includes a layer forming member to form a toner layer on a developing roller and forms a toner image by developing the electrostatic latent image. The transfer device transfers the toner image to a sheet. The fixing device fixes the toner image to the sheet. The history acquisition unit acquires a history regarding a temperature around the developing device. The estimation unit estimates a possibility that an image defect caused by the layer formation may occur on the basis of the history. The output unit outputs estimation results of the estimation.

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 imaging system includes an image carrier, a charging device to form a toner image by charging a surface of the image carrier, a polishing roller, and a control device. A discharge product is generated on the surface of the image carrier as a result of charging the image carrier, and the polishing roller polishes the discharge product generated on the surface of the image carrier. The control device controls a polishing operation of the polishing roller in response to one or more detected characteristics.