Abstract: The image forming apparatus includes a fixing device that has a heater, and a required power calculation unit that determines a power Pfsr that is assumed to be required by the heater. Based on a difference between a required power that is determined by the required power calculation unit and a suppliable power, the image forming apparatus selects whether to start printing in a normal mode or to start printing in a power saving mode in which the power that is supplied to the heater is reduced in comparison to the normal mode. The power saving mode includes a plurality of modes, and when a CPU selects the power saving mode, the CPU selects one or a combination of modes from among the plurality of power saving modes based on the aforementioned difference.

Abstract: The image forming apparatus includes a fixing device that has a heater, and a required power calculation unit that determines a power Pfsr that is assumed to be required by the heater. Based on a difference between a required power that is determined by the required power calculation unit and a suppliable power, the image forming apparatus selects whether to start printing in a normal mode or to start printing in a power saving mode in which the power that is supplied to the heater is reduced in comparison to the normal mode. The power saving mode includes a plurality of modes, and when a CPU selects the power saving mode, the CPU selects one or a combination of modes from among the plurality of power saving modes based on the aforementioned difference.

Abstract: A fixing unit includes a changing portion configured to change a state of a first rotary member and a second rotary member between a first pressurization state and a second pressurization state. A control portion is configured to control the driving source and the changing unit and capable of performing first control that causes the driving source to rotate the first rotary member and then stop the first rotary member, while continuing the first pressurization state from a last image forming operation, and second control that causes the changing portion to change the state of the first rotary member and the second rotary member from the first pressurization state to the second pressurization state.

Abstract: The image forming apparatus includes a fixing device that has a heater, and a required power calculation unit that determines a power Pfsr that is assumed to be required by the heater. Based on a difference between a required power that is determined by the required power calculation unit and a suppliable power, the image forming apparatus selects whether to start printing in a normal mode or to start printing in a power saving mode in which the power that is supplied to the heater is reduced in comparison to the normal mode. The power saving mode includes a plurality of modes, and when a CPU selects the power saving mode, the CPU selects one or a combination of modes from among the plurality of power saving modes based on the aforementioned difference.

Abstract: A fixing unit includes a changing portion configured to change a state of a first rotary member and a second rotary member between a first pressurization state and a second pressurization state. A control portion is configured to control the driving source and the changing unit and capable of performing first control that causes the driving source to rotate the first rotary member and then stop the first rotary member, while continuing the first pressurization state from a last image forming operation, and second control that causes the changing portion to change the state of the first rotary member and the second rotary member from the first pressurization state to the second pressurization state.

Abstract: The image forming apparatus includes a fixing device that has a heater, and a required power calculation unit that determines a power Pfsr that is assumed to be required by the heater. Based on a difference between a required power that is determined by the required power calculation unit and a suppliable power, the image forming apparatus selects whether to start printing in a normal mode or to start printing in a power saving mode in which the power that is supplied to the heater is reduced in comparison to the normal mode. The power saving mode includes a plurality of modes, and when a CPU selects the power saving mode, the CPU selects one or a combination of modes from among the plurality of power saving modes based on the aforementioned difference.

Abstract: A sheet feeding device includes a sheet storage unit, a stacking unit, a raising unit, a sheet detection unit, an attachment detection unit, and a control unit. The sheet storage unit may be attached to and drawn out of an apparatus main body. The stacking unit is raised by the raising unit and is lowered when the sheet storage unit is drawn out. The attachment detection unit detects attachment of the sheet storage unit to the apparatus main body. The control unit determines whether an amount of sheets stacked on the stacking unit exceeds a predetermined amount based on detection results. If the sheet detection unit continues to detect sheets when the sheet storage unit goes from attached, to not attached, to attached to the apparatus main body, the control unit determines that the amount of sheets stacked on the stacking unit does not exceed the predetermined amount.

Abstract: A sheet feeding device includes a sheet storage unit, a stacking unit, a raising unit, a sheet detection unit, an attachment detection unit, and a control unit. The sheet storage unit may be attached to and drawn out of an apparatus main body. The stacking unit is raised by the raising unit and is lowered when the sheet storage unit is drawn out. The attachment detection unit detects attachment of the sheet storage unit to the apparatus main body. The control unit determines whether an amount of sheets stacked on the stacking unit exceeds a predetermined amount based on detection results. If the sheet detection unit continues to detect sheets when the sheet storage unit goes from attached, to not attached, to attached to the apparatus main body, the control unit determines that the amount of sheets stacked on the stacking unit does not exceed the predetermined amount.