An image forming apparatus including: a cyclone which centrifugally separates toner from air containing the toner scattered; a storage which stores the toner separated by the cyclone; a filtering portion which allows air to pass, the air being obtained after the toner is separated by the cyclone; a duct which guides the air that passes through the filtering portion; a fan which generates a flow of the air to discharge the air that passes through the filtering portion; and a hardware processor which measures a rotational speed of the fan, detects a full state in which the storage is filled with the toner based on change of the rotational speed of the fan, and issues a warning in a case in which a variation rate of rotational speeds of the fan measured a plurality of times is a predetermined value or more.

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.

In an image forming apparatus, a bias controller varies one, while keeping the other fixed, of a charging alternating-current frequency, which is the frequency of the charging alternating-current voltage, and a developing alternating-current frequency, which is the frequency of the developing alternating-current voltage. Specifically, in a case where interference fringes appear in a developed image due to interference between the charging and developing alternating-current frequencies, when the recognizable minimum pitch of the interference fringes is A.sub.1 (mm), the width of the variation region of the other frequency is B.sub.1 (Hz), the rotation speed of an image carrying member is C.sub.1 (mm/sec), and the variation speed of the other frequency in the variation region is D.sub.1 (Hz/sec), the bias controller varies the other frequency at a variation speed D.sub.1 that fulfills |D.sub.1|>B.sub.1/(A.sub.1/C.sub.1).

An apparatus includes a forming unit, a cleaning mechanism that cleans a transparent member of a scanning device of the forming unit, a counter that counts a number of image-formed sheets, which are sheets of a recording medium on which images have been formed by the forming unit, the counter performing counting with a first count value in a case where the forming unit performs image formation in a first mode and performing counting with a second count value larger than the first count value in a case where the forming unit performs image formation in a second mode higher in image forming speed than the first mode, and a control unit that controls the cleaning mechanism to clean the transparent member in response to the number of image-formed sheets counted by the counter reaching a predetermined number of sheets.

In a first operation mode in which a first addition value for each sheet of a recording material and a first initial control temperature, when the total sum of the first addition values exceeds a predetermined threshold value, control portion of an image heating portion, which heats an image on the recording material, of an image forming apparatus changes the first initial control temperature to a first correction control temperature. When the operation mode is changed from the first operation mode to a second operation mode in which a second addition value different from the first addition value and a second initial control temperature different from the first initial control temperature, the control portion corrects the first correction control temperature based on a difference between the initial control target temperatures.

An image forming apparatus includes: a fixer including fixing rotation body and pressing rotation body with a fixing nip therebetween, and heats and presses a fed sheet through the fixing nip to fix a toner image on the sheet to the sheet; and a hardware processor making a velocity difference between respective surface velocities of the fixing rotation body and the sheet passing through the fixing nip during a high-gloss mode operation to adjust a gloss of the toner image on the sheet. The hardware processor performs a control so that an absolute value of a velocity difference between respective surface velocities of the fixing rotation body and the pressing rotation body in press-contact when the sheet does not pass through the fixing nip is less than one between respective surface velocities of the fixing rotation body and the sheet when the sheet passes through the fixing nip during the high-gloss mode operation.

An image forming apparatus includes: a photoreceptor; a transferer; a remover that removes toner on a surface of the photoreceptor; and a hardware processor that: performs a control to form a toner image based on a print image on paper according to a first formation condition by using at least the photoreceptor and the transferer; performs a control to form a toner patch on the surface of the photoreceptor according to a second formation condition determined on the basis of the first formation condition at the time of forming the toner image on the paper by the hardware processor; and controls a voltage applied to the transferer to be a voltage at which the toner patch formed on the photoreceptor is not transferred when the toner patch formed on the surface of the photoreceptor passes through a region facing the transferer.

An apparatus includes a forming unit, a cleaning mechanism that cleans a transparent member of a scanning device of the forming unit, a counter that counts a number of image-formed sheets, which are sheets of a recording medium on which images have been formed by the forming unit, the counter performing counting with a first count value in a case where the forming unit performs image formation in a first mode and performing counting with a second count value larger than the first count value in a case where the forming unit performs image formation in a second mode higher in image forming speed than the first mode, and a control unit that controls the cleaning mechanism to clean the transparent member in response to the number of image-formed sheets counted by the counter reaching a predetermined number of sheets.

An image forming apparatus includes an image forming portion configured to form an image on a recording material, and a fixing portion including a first rotatable member and a second rotatable member, rotatable by rotation of the first rotatable member, and in contact with the first rotatable member. The fixing portion fixes the image on the recording material by heating the image while nipping and feeding the recording material, on which the image is formed, at a nip formed between the first rotatable member and the second rotatable member. A motor drives the first rotatable member, and torque detecting means detects a driving torque of the motor. On the basis of the driving torque detected by the torque detecting means, a controller controls a degree of temperature rise of the first rotatable member immediately before the recording material enters the nip.

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.