An image forming apparatus includes a plurality of temperature-influence members, a first-point temperature acquisition unit, a second-point temperature estimation unit, and a controller. The plurality of temperature-influence members have influence on a temperature of a recording medium on which an image is formed. The first-point temperature acquisition unit is configured to detect or estimate a temperature of the recording medium at a first point. The second-point temperature estimation unit is configured to estimate a temperature of the recording medium at a second point, based on a detection result of at least one of a temperature of the recording medium at a point different from the second point and a temperature of a member or atmosphere. The controller is configured to control the plurality of temperature-influence members, based on an acquisition result from the first-point temperature acquisition unit and an estimation result from the second-point temperature estimation unit.

An image forming apparatus includes a heater, a fixing device, and a controller. The heater includes a heat generator that generates heat when the heater is turned on. The fixing device may fix a developer image on a surface of an image forming medium using the heat from the heat generator. The controller detects a voltage of a power supply for supplying electric power to the heater, and determines an occurrence of an abnormality in the heater if a voltage drop amount at the time the heater is turned on as compared to a case in which the heater is turned off is smaller than a first threshold value.

An image forming apparatus includes a fixing device having a heater that includes a first heating element, a second heating element having a length smaller than the first heating element length, and a third heating element having a length smaller than the second heating element length. The image forming apparatus further includes a first temperature detection unit, a control unit, second temperature detection units, first and second sheet-width detection units, and a determination unit. The control unit controls a heater temperature based on the first temperature detection unit detection result. The determination unit determines a width of the recording material based on a detection result of the first sheet-width detection units, a detection result of the second sheet-width detection units, and a detection result of the second temperature detection units.

When it is judged that a predetermined operation for eliminating a cause for stopping a job is being executed, a following job is restricted from being executed prior to a stopped job. A control method for controlling a job processing apparatus for storing received jobs in a storage unit and sequentially executing the stored jobs includes determining, when a cause for stopping the job to be executed is generated, whether a state in which the cause for stopping the job is not eliminated has continued for a predetermined time, executing, when it is determined that the state in which the cause for stopping the job is not eliminated has continued for the predetermined time, a following job that follows the job is executed prior to the job, judging whether a predetermined operation for eliminating the cause for stopping the job is being executed, and restricting, when it is judged that a predetermined operation for eliminating the cause for stopping the job is being executed, the following job is restricted from being executed prior to the job.

An image forming apparatus includes a latent image forming portion configured to form a latent image on an image bearing member; a developing device including a container configured to store toner and a developing member configured to supply the toner to the latent image formed on the image bearing member to form a toner image; an environment sensor configured to detect environmental information related to an environment in which the developing device is placed; and a controller configured to control switching between a first mode and a second mode, in which a number of prints per unit time is less than that in the first mode. The controller is configured to perform switching from the first mode to the second mode based on an update value obtained by adding or subtracting over time an index value weighted in accordance with the environmental information detected by the environment sensor.

An image forming apparatus includes: an image forming device that forms an image on a sheet; a fixing device that includes a heating member and heats the sheet on which the image is formed by the image forming device, to fix the image on the sheet; a detector that detects a temperature in the fixing device; and a hardware processor that performs PID control of a turn-on rate of the heating member according to a deviation between a detected temperature by the detector and a target temperature, the PID control being in accordance with an expression including at least a proportional term or an integral term and further including a constant term of a value corresponding to an operation condition of the apparatus, wherein the hardware processor calculates an average turn-on rate of the heating member during execution of the operation, and updates the value of the constant term.

An image forming apparatus includes an image forming unit, a storage portion to which a heating unit configured to heat the sheet stored in the storage portion is detachably attached, a conveyance unit, a detection unit configured to detect attachment of the heating unit to the storage portion, and a control unit configured to control the conveyance unit such that a standby time by which conveyance of the sheet fed from the storage portion is stopped is shorter when the detection unit detects the heating unit than when the detection unit does not detect the heating unit.

An image forming apparatus comprises a first temperature detector to detect a temperature of a first portion of an optical scanning device in a printer. The first portion is proximate to a heat generating element in the optical scanning device. A second temperature detector is provided to detect a temperature of a second portion of the optical scanning device, which is farther from the heat generating element than the first portion. A controller is configured to perform alignment control for correcting a color positional shift of the printer when either a detected temperature change of the first portion is greater than or equal to a first threshold value or a detected temperature change of the second portion is greater than or equal to a second threshold value.

An image forming apparatus includes a control unit that changes a ratio between an execution time for executing printing and a stop time for stopping the printing according to any one of a stop control number that is the number of times that an operation of the printing is stopped, a stop control time that is the time during which the operation of the printing is stopped, a printing execution time that is the time during which the printing is executed, and a printing execution control number that is the number of times that the printing is executed, in an intermittent mode that operates by switching between executing the printing and stopping the printing.

An image forming apparatus including: a fixer that fixes a toner image formed on a recording medium by pressing and heating the recording medium nipped in a nip portion formed by causing two rotating bodies to pressedly abut on each other, and conveying the recording medium by rotating the rotating bodies; a motor that drives the rotating bodies by transmitting a torque to at least one of the rotating bodies; a torque detector that detects the torque transmitted to the rotating body by the motor; a temperature detector that detects temperature of the rotating body; a speed detector that detects a conveyance speed for conveying the recording medium by the fixer; and a controller that corrects the detected torque based on at least any one of the detected temperature and the detected conveyance speed and predicts a life of the fixer based on the corrected torque.