An image forming apparatus includes an image forming portion, an adjustment processing portion, an acquisition processing portion, and a setting processing portion. The image forming portion forms an image using toner. During execution of an image forming process using the image forming portion, the adjustment processing portion uses the toner to adjust the image quality of an output image output by the image forming process. The acquisition processing portion acquires variation amount information related to the amount of variation in a predetermined state value related to the image forming portion caused by a start of the image forming process. The setting processing portion sets the frequency of adjustment of the image quality of the output image by the adjustment processing portion, based on the variation amount information acquired by the acquisition processing portion.

An image forming apparatus includes an adjustment processing portion, an acquisition processing portion, and a determination processing portion. Each time an adjustment condition is satisfied during execution of an image forming process, the adjustment processing portion uses toner to adjust one adjustment target selected in accordance with a specific order among a plurality of adjustment targets related to image quality of an output image output by the image forming process. The acquisition processing portion acquires variation amount information related to an amount of variation in a state value related to an image forming portion caused by a start of the image forming process. The determination processing portion determines an adjustment target to be adjusted first after the start of the image forming process by the adjustment processing portion, based on the variation amount information acquired by the acquisition processing portion.

A fixing device includes a film forming a cylinder, a heater, a thermometer, and a series of contact portions. The heater extends within the cylinder and includes a heating element that extends in a longitudinal direction along the cylinder. The thermometer detects a temperature of the cylinder. The plurality of contact portions contact an inner surface of the cylinder and are spaced apart from each other in the longitudinal direction. The contact portions include a first contact portion and a second contact portion. The first contact portion is longitudinally offset from the thermometer and has a first contact area with the cylinder. The second contact portion is longitudinally collocated with the thermometer and has a second contact area with the cylinder. The second contact area is smaller than the first contact area.

A fixing device includes a fixing belt, a planar heater, a pressure rotator, a temperature sensor, and a plate. The pressure rotator presses the planar heater to form a nip through which a sheet is conveyed in a conveyance direction. The plate contacts the planar heater and includes a first portion and a second portion. The first portion has an opening and a projection. The temperature sensor contacts the planar heater through the opening to detect a temperature of the planar heater. The projection projects from the opening in the conveyance direction. The first portion has a first width in the conveyance direction. The second portion is inside a minimum sheet-passing region in an axial direction of the pressure rotator orthogonal to the conveyance direction and outside the first portion in the axial direction and has a second width smaller than the first width in the conveyance direction.

An image forming apparatus includes an image bearing member, a transfer member, an acquiring portion, an applying portion, and a controller. When a transfer voltage is subjected to constant-voltage control so that the transfer voltage applied to the transfer member by the applying portion is substantially constant, in a case that the transfer voltage, when a toner amount used for a toner image is a first toner amount, is a first voltage, the controller controls the applying portion so that the transfer voltage is a second voltage smaller lower in absolute value than the first voltage in a case that the toner amount is a second toner amount larger greater than the first toner amount. The acquiring portion acquires toner amount information on the toner amount for each toner image transferred onto a single recording material.

A fixing device includes a film forming a cylinder, a heater, a thermometer, and a series of contact portions. The heater extends within the cylinder and includes a heating element that extends in a longitudinal direction along the cylinder. The thermometer detects a temperature of the cylinder. The plurality of contact portions contact an inner surface of the cylinder and are spaced apart from each other in the longitudinal direction. The contact portions include a first contact portion and a second contact portion. The first contact portion is longitudinally offset from the thermometer and has a first contact area with the cylinder. The second contact portion is longitudinally collocated with the thermometer and has a second contact area with the cylinder. The second contact area is smaller than the first contact area.

A fixing device includes a heating rotating member and a pressure rotating member and performs image formation in one mode out of a plurality of modes including a first mode and a second mode. A time during which one of the heating rotating member and the pressure rotating member moves between an abutment position and a separation position in a case where the image formation is performed in the first mode is a first time, a time during which the one moves between the abutment position and the separation position in a case where the image formation is performed in the second mode is a second time, and the first time is shorter than the second time.

An image-forming apparatus includes a photosensitive drum, a development member, an intermediate transfer belt, a transfer member, a transfer voltage, a density detection unit, a temperature detection unit, and a control unit. The development member forms a toner image on a surface of the photosensitive drum, which the transfer member transfers to the intermediate transfer belt. The density detection unit detects an information related to a density of the toner image transferred to the intermediate transfer belt. The control unit controls a driving speed of the intermediate transfer belt. In a detection operation in which the density detection unit detects the information related to the density of the toner image transferred to the intermediate transfer belt in a state where the transfer voltage is applied to the transfer member, the control unit controls the driving speed based on an ambient temperature detected by the temperature detection unit.

According to an embodiment, an image forming apparatus includes a developing device including a toner receiving portion configured to contain toner and a movable part moveable at a first speed and a second speed, the moveable part at least partially disposed within the toner receiving portion, a temperature sensor disposed adjacent to the developing device, and a control unit operatively coupled to the temperature sensor and the developing device, wherein the control unit controls the movable part to move at a first speed when the temperature sensor detects a temperature less than a first temperature and controls the movable part to move at a second speed lower than the first speed when the detected temperature is less than a second temperature that is greater than the first temperature.

An image forming apparatus includes: a photosensitive drum for bearing a developer; a charging roller that comes into contact with the photosensitive drum at a different velocity and that charges the photosensitive drum; a transfer roller that transfers a developer image on the photosensitive drum to a recording material; a developing sleeve that supplies a developer to the photosensitive drum and that recovers a developer on the photosensitive drum after transfer; detecting device for detecting information relating to injection charging; and a controller that, based on the information, controls an amount of a fogging developer, wherein the controller controls the amount of the fogging developer during image formation according to information detected by the detecting device while suppressing the amount of the developer recovered in the developing sleeve.