According to one embodiment, a temperature control device stores a fixing device temperature estimation value and a storage time obtained by WAE control in a memory at any time during operation. After an electric power supply to the temperature control device is stopped, the next time the electric power supply is started, an electric power supply stop period until the electric power supply is started is calculated. If the electric power supply stop period is shorter than a set time, the WAE control is started by using the stored fixing device temperature estimation value, and if the electric power supply stop period exceeds the set time, the WAE control is started based on an initial set value.

According to one embodiment, a temperature control device stores a fixing device temperature estimation value and a storage time obtained by WAE control in a memory at any time during operation. After an electric power supply to the temperature control device is stopped, the next time the electric power supply is started, an electric power supply stop period until the electric power supply is started is calculated. If the electric power supply stop period is shorter than a set time, the WAE control is started by using the stored fixing device temperature estimation value, and if the electric power supply stop period exceeds the set time, the WAE control is started based on an initial set value.

A power supply apparatus including a switching element configured to supply or cut off electric power to a primary coil of a transformer by a switching operation, and a control unit configured to control the switching operation. The control unit is configured to perform intermittent control of repeating a switching period for performing the switching operation and a stop period for stopping the switching operation. In the switching period, when the control unit performs the switching operation a predetermined number of times, the switching period is transitioned to the stop period. In the stop period, when the control unit determines that a voltage output from a secondary coil of the transformer falls below a target voltage, the stop period is transitioned to the switching period. The control unit is configured to change the switching operation based on a length of the stop period.

An apparatus provided with a power source device indicating a converting unit includes a switching unit, a discriminating unit, and a controller. In the case where the discriminating unit discriminates that an overcurrent state occurs during an operation of the power source device in a first mode, the mode of the operation of the power source device is switched to a second mode by the switching unit and then the occurrence of the overcurrent state is notified.

An image forming system includes: a conveyor that conveys a recording material along a conveyance path; a detector that is disposed on the conveyance path and detects a characteristic of the recording material; a fixer that fixes a toner image formed on the recording material; and a hardware processor that: causes the detector to detect the characteristic during a warm-up of the fixer with respect to an image forming job, and based on the characteristic, sets an image forming condition in the image forming job.

A fixing device includes a fixing roller and a pressure roller provided in a rotatable manner, a heat source for heating the fixing roller, and a controller for controlling AC power supplied to the heat source. The fixing device fixes an unfixed image on a sheet held and conveyed by the fixing roller and the pressure roller. The controller causes a current to flow including current-carrying waveforms having different phase angles in half-wave units during preset control cycles.

The heating apparatus including a plurality of heat generation members including first, second and third generation members, the second heat generation member and the third heat generation member having lengths in a longitudinal direction shorter than a length of the first heat generation member, the heating apparatus including first, second, third, and fourth contacts, and a first switching unit configured to bring an electric path between the second contact and the fourth contact into one of a connecting state and an open state.

The image forming apparatus includes a cartridge replaceable by detachably mounting to the image forming apparatus, a door that takes a closed state or an open state, a locking pin that switches a state of the regulation unit between a regulating state in which the replacement unit is prevented to be detached from the image forming apparatus and a release state in which the replacement unit is to be detachable from the image forming apparatus, and a lock control unit (a control unit) that makes a determination as to whether or not the state of the regulation unit is to be switched from the release state to the regulating state, at a predetermined timing when initial processing is completed after a power source is turned on or a state of the door becomes the closed state from the open state.

A fixing device heats and fixes a toner image formed on a sheet to the sheet. The fixing device includes a heat roller and a ground contact. The heat roller heats the toner image formed on the sheet. The ground contact grounds the heat roller. The ground contact includes a first electrical conductive member, a second electrical conductive member, and an electrical insulating member. The first electrical conductive member is electrically connected to the heat roller. The second electrical conductive member is positioned opposite the first electrical conductive member and grounds the heat roller. The electrical insulating member is interposed between the first electrical conductive member and the second electrical conductive member and insulates the first electrical conductive member and the second electrical conductive member from each other.

An image forming apparatus includes a detection unit configured to detect an object, a reception unit configured to receive an operation of a user, and a shifting unit configured to shift, if the detection unit detects an object, a power state of the image forming apparatus from a first power state to a second power state different from the first power state, and shift, if the reception unit receives an operation of a user, the power state of the image forming apparatus from the second power state to the first power state.