An image forming apparatus includes a photosensitive member, a charging member, an exposure member, a rotatable developer carrying member, a voltage source, and a controller configured to control the voltage source so that when a humidity of an inside of the apparatus is a first humidity, a developing bias voltage including an oscillating portion having an oscillating voltage and a rest portion having a substantially constant voltage are alternately repeated is outputted and so that when the humidity of the inside of the apparatus is a second humidity lower than the first humidity, a developing bias voltage in which the rest portion is not included or is shorter than the rest portion when the humidity of the inside of the apparatus is the first humidity.

An image forming apparatus includes an image forming portion, a heating portion that includes a heating element which is heated by power from a power supply and heats an image, a temperature detecting portion that detects temperature of the heating portion, and a power control portion that controls power supplied to the heating element based on information from the temperature detecting portion. The image forming apparatus further includes a detecting portion that detects whether voltage from the power supply exceeds a rated value, and when the detecting portion detects that the voltage from the power supply exceeds the rated value, the power control portion controls the power supply such that a waveform pattern of an electric current to the heating element in one control cycle becomes a waveform pattern of phase control, where power supplying time to the heating element in one half wave becomes a predetermined time or less.

An image forming apparatus includes a temperature sensor, a memory, a fixing device, and a controller. The temperature sensor is configured to detect a temperature of an inside of the image forming apparatus. The memory is configured to store temperature history information regarding a history of the temperature of the inside of the image forming apparatus detected by the temperature sensor. The fixing device is configured to fix a toner image onto the paper sheet by heating the paper sheet to a fixing temperature. The toner image is transferred to the paper sheet using a toner stored in a toner cartridge of the image forming apparatus. The controller is configured to control a fixing temperature at the fixing device based on the temperature history information stored in the memory.

According to one embodiment, an image forming apparatus includes an image forming unit, a first temperature sensor, a second temperature sensor, a cooling mechanism, and a controller. The first temperature sensor detects the internal temperature of a machine body where the image forming unit is arranged. The second temperature sensor detects the environmental temperature of the environment where the machine body is placed. The cooling mechanism cools the image forming unit. The controller adjusts the cooling capacity of the cooling mechanism based on the result of comparing the internal temperature detected by the first temperature sensor with a first threshold, and the result of comparing the environmental temperature detected by the second temperature sensor with a second threshold lower than the first threshold.

An image forming apparatus including a print engine, a power supply device, a plurality of temperature sensors, and a processor. The print engine including a fuser. The power supply device to selectively provide power to the fuser. The plurality of temperature sensors including a first temperature sensor and a second temperature sensor to sense temperature of the fuser. The processor to control power supplied to the fuser based on a value measured by at least one temperature sensor from among the plurality of temperature sensors. The processor is to identify whether the at least one temperature sensor of the plurality of temperature sensors has an abnormality based on a first measured temperature value and a second measured temperature value of the plurality of temperature sensors.

An image forming apparatus includes a processor. The processor is configured to emit a laser beam reflected by a polygon mirror, the polygon mirror rotated by a polygon motor, form an image based on a latent image carried on a photoconductor by the laser beam, store an execution frequency of an image quality self-check of the image formed and a rotation duration of the polygon motor during a standby operation period of image formation, accept a change in the execution frequency, change the rotation duration based on the change in the execution frequency, execute the image quality self-check based on the execution frequency, and continuously rotate the polygon motor during the standby operation period based on the rotation duration stored.

An image forming apparatus includes a fixing device including a heating roller configured to heat a sheet when the heating roller rotates, a temperature sensor configured to detect a temperature of the heating roller; and a controller configured to obtain a temperature detected by the temperature sensor at intervals of a predetermined sampling time, calculate, at the intervals of the predetermined sampling time, a temperature-decrease-amount of the detected temperature over a unit time that is longer than the predetermined sampling time, and stop rotation of the heating roller when the calculated temperature-decrease-amount is greater than a predetermined threshold value.

An image forming apparatus includes a developer bearing member, a frame having a storage member, and a first temperature detection unit. The storage member is for storing a developer for the developer bearing member to record an image on a recording material. The storage member includes an attachment part in which a supply container enclosing a developer is removably attachable to the attachment part. With reference to a recording material conveyance path having a center in a width direction of the recording material that is orthogonal to a recording material conveyance direction and in a case where an area on one side of the conveyance path center is a first area and the area on the other side of the conveyance path center is a second area, the attachment part is arranged in the first area and the first temperature detection unit is arranged in the second area.

An image forming apparatus that forms images on sheets, includes: a collection unit configured to collect history information relating to operation of the image forming apparatus; a selection unit configured to select, from among a plurality of accomplishment items, an accomplishment item relating to the operation of the image forming apparatus based on the history information; an acquisition unit configured to notify a user of one or more operation options related to the operation of the image forming apparatus that are for accomplishing the accomplishment item selected by the selection unit, and to acquire a selection result of whether or not the one or more operation options are to be used; and an operation control unit configured to control the operation of the image forming apparatus in accordance with the selection result.

A control unit controls power to be supplied to a common power supply path in a first period, using a selected first temperature detection member, and controls power to be supplied to the common power supply path in a second period, using a selected second temperature detection member. The first temperature detection member has a higher detected temperature than that of the second temperature detection member, and in the second period, the first detected temperature and the second detected temperature fall within a temperature range between a first temperature and a second temperature lower than the first temperature.