Abstract: A heating device includes a heater, an AC-voltage input section between which an AC voltage is applied, a fuse, a switcher, an AC-voltage-abnormality detector configured to detect an abnormality of the AC voltage, a controller. The controller is configured to execute a current-flowing operation in a state in which connection of a first connection terminal to a second connection terminal is a non-connecting state. The current-flowing operation is an operation in which an electrical current flows through the heater. The controller is configured to execute a connecting process in response to detection of the abnormality of the AC voltage by the AC-voltage-abnormality detector detected in the middle of the current-flowing operation. The connecting process is a process of switching a connection of a first connecting point to a second connecting point from a non-connecting state to a connecting state.

Abstract: A heating device includes a heater, an AC-voltage input section between which an AC voltage is applied, a fuse, a switcher, an AC-voltage-abnormality detector configured to detect an abnormality of the AC voltage, a controller. The controller is configured to execute a current-flowing operation in a state in which connection of a first connection terminal to a second connection terminal is a non-connecting state. The current-flowing operation is an operation in which an electrical current flows through the heater. The controller is configured to execute a connecting process in response to detection of the abnormality of the AC voltage by the AC-voltage-abnormality detector detected in the middle of the current-flowing operation. The connecting process is a process of switching a connection of a first connecting point to a second connecting point from a non-connecting state to a connecting state.

Abstract: An image forming apparatus includes a controller configured to begin to supply AC power to a first heater at a start of a first half-cycle of the AC power, begin to supply the AC power to a second heater at a first timing after beginning to supply the AC power to the first heater, in the first half-cycle, when an estimated combined peak current is more than a threshold, begin to supply the AC power to the second heater at a second timing in a second half-cycle next to the first half-cycle, the second timing satisfying that a time period between a start of the second half-cycle and the second timing is equal to a time period between the start of the first half-cycle and a timing from which the estimated combined current is equal to or less than the threshold until the end of the first half-cycle.

Abstract: An image forming apparatus includes a controller configured to begin to supply AC power to a first heater at a start of a first half-cycle of the AC power, begin to supply the AC power to a second heater at a first timing after beginning to supply the AC power to the first heater, in the first half-cycle, when an estimated combined peak current is more than a threshold, begin to supply the AC power to the second heater at a second timing in a second half-cycle next to the first half-cycle, the second timing satisfying that a time period between a start of the second half-cycle and the second timing is equal to a time period between the start of the first half-cycle and a timing from which the estimated combined current is equal to or less than the threshold until the end of the first half-cycle.

Abstract: An image forming apparatus including: a fixing device including a heater and a temperature sensor, and a controller configured to execute: first heater control processing including: first processing of driving the heater with a predetermined energization ratio for a first time period independently of the detected temperature of the temperature sensor; second processing of stopping the driving of the heater for a second time period independently of the detected temperature of the temperature sensor; the second processing being executed when the first processing has ended, comparison processing of comparing a detected temperature of the temperature sensor with a reference temperature, which is executed when the second processing has ended; and first determination processing of determining whether to execute the first processing again based on the result of the comparison processing which has been executed when the second processing had ended.

Abstract: An image forming apparatus includes a process unit, a controller, and a fixing unit including a heater. The process unit is configured to form a developer image on a sheet. The heater is configured to be applied with an AC voltage, and to heat the sheet to thereby fix the developer image to the sheet. The controller is configured to perform: executing a continuous supply control in which the heater is continuously energized; acquiring an initial voltage dropping level of the AC voltage and a recovery time during the executing the continuous supply control; and setting a power supply control to control energization of the heater for starting up the heater on the basis of the acquired initial voltage dropping level and the acquired recovery time.

Abstract: An image forming apparatus includes a process unit, a controller, and a fixing unit including a heater. The process unit is configured to form a developer image on a sheet. The heater is configured to be applied with an AC voltage, and to heat the sheet to thereby fix the developer image to the sheet. The controller is configured to perform: executing a continuous supply control in which the heater is continuously energized; acquiring an initial voltage dropping level of the AC voltage and a recovery time during the executing the continuous supply control; and setting a power supply control to control energization of the heater for starting up the heater on the basis of the acquired initial voltage dropping level and the acquired recovery time.

Abstract: An image forming apparatus including: a fixing device including a heater and a temperature sensor, and a controller configured to execute: first heater control processing including: first processing of driving the heater with a predetermined energization ratio for a first time period independently of the detected temperature of the temperature sensor; second processing of stopping the driving of the heater for a second time period independently of the detected temperature of the temperature sensor; the second processing being executed when the first processing has ended, comparison processing of comparing a detected temperature of the temperature sensor with a reference temperature, which is executed when the second processing has ended; and first determination processing of determining whether to execute the first processing again based on the result of the comparison processing which has been executed when the second processing had ended.