A remaining toner amount detecting apparatus detects a remaining toner amount in a toner bottle. The remaining toner amount detecting apparatus includes at least one pair of electrodes that are configured to face each other with the toner bottle interposed between the electrodes; a first estimator configured to estimate the remaining toner amount based on a capacitance between the electrodes of the at least one pair of electrodes; a second estimator configured to estimate the remaining toner amount by counting a number of pixels in a printed image; and an estimation selector configured to use either one of the first estimator or the second estimator to output the remaining toner amount, based on a temperature or a humidity inside an apparatus in which the toner bottle is mounted.

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.

A control unit of the invention compares printing setting suitable for a determined type of a recording material and printing setting of the recording material input by a user, and in a case where a difference between the printing setting suitable for the determined type of the recording material and the printing setting of the recording material input by the user falls in a predetermined range, the control unit performs a printing operation in accordance with the printing setting of the recording material input by the user, and in a case where the difference is greater than the predetermined range, the control unit performs the printing operation by changing the printing setting of the recording material input by the user, which is used when the difference is smaller than the predetermined range.

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 system includes: an image forming apparatus that includes a transfer device that transfers a toner image onto a sheet and a fixing device that fixes the toner image; a sheet heating device that heats the sheet on an upstream of the fixing device in a sheet conveyance direction; a first detector that detects a temperature inside the image forming apparatus; a second detector that detects a temperature of the sheet before the sheet heating device heats the sheet; and a controller that causes the sheet heating device to heat the sheet based on a detection result by the second detector and a sheet passing condition of the sheet, and corrects at least one of a transfer current and a transfer voltage in the transfer device based on a detection result by the first detector in a case where the sheet heating device heats the sheet.

An image forming apparatus includes a toner image forming unit, a fuser including a heater, a temperature sensor that detects a temperature of the fuser, and a controller. The controller exercises a standby control that includes repeating a control cycle, measuring a temperature fluctuation period that is a time period from start of energizing the heater to an end of the control cycle, and setting an energization amount for a next control cycle, based on the measured temperature fluctuation period. The control cycle includes energizing the heater with an energization amount during a preset heating period when the detection temperature has dropped to a temperature below the target standby temperature, and waiting until the detection temperature drops to the target standby temperature in a case where the detection temperature has risen to a temperature equal to or above the target standby temperature after the preset heating period has elapsed.

A control unit of the invention compares printing setting suitable for a determined type of a recording material and printing setting of the recording material input by a user, and in a case where a difference between the printing setting suitable for the determined type of the recording material and the printing setting of the recording material input by the user falls in a predetermined range, the control unit performs a printing operation in accordance with the printing setting of the recording material input by the user, and in a case where the difference is greater than the predetermined range, the control unit performs the printing operation by changing the printing setting of the recording material input by the user, which is used when the difference is smaller than the predetermined range.

An image forming apparatus that forms an image on a sheet includes: a rotating body that forms the image; a motor that rotationally drives the rotating body; a current measurer that measures a motor current flowing through a current supply path including a winding of the motor at a measurement timing that is a timing after the motor is started; a torque acquisitor that acquires a torque value of the motor, based on a measured value of the motor current; and a corrector that performs correction to cancel a current change amount based on a characteristic change depending on a temperature state of the motor at the measurement timing, in acquisition of the torque value by the torque acquisitor.

The image forming apparatus stores a plurality of candidate formulas in a memory. Each of the candidate formulas are a formula for calculating a prediction formula for calculating a predicted value of the color misregistration amount based on an external exposure device temperature which is a temperature of the atmosphere around the exposure device, an external machine temperature, and a heater temperature of a heater which heats the plurality of image forming units. The CPU determines the prediction formula from the plurality of candidate formulas according to the external exposure device temperature, the external machine temperature, and the heater temperature. The CPU calculates the predicted value of the color misregistration amount using the determined predicted formula, and perform a color misregistration correction according to the calculated predicted value.

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.