Abstract: A fixing member is supported so as to be displaceable in a crossing direction that crosses a sheet conveying direction. A pressure member rotationally drives the fixing member by being rotationally driven. A motor rotationally drives the pressure member. A biasing mechanism elastically biases the fixing member toward the pressure member. A sheet detection portion detects a sheet at a first position and a second position. The first position is a position between a mechanism that feeds the sheet to a fixing position and the fixing position in the conveyance path. The second position is a position between the fixing position and a mechanism that takes over conveyance of the sheet from the fixing device. A control device times a time required for detection results from the sheet detection portion to show a predetermined change, and controls a rotational speed of the motor according to the timed time.

Abstract: A fixing member is supported so as to be displaceable in a crossing direction that crosses a sheet conveying direction. A pressure member rotationally drives the fixing member by being rotationally driven. A motor rotationally drives the pressure member. A biasing mechanism elastically biases the fixing member toward the pressure member. A sheet detection portion detects a sheet at a first position and a second position. The first position is a position between a mechanism that feeds the sheet to a fixing position and the fixing position in the conveyance path. The second position is a position between the fixing position and a mechanism that takes over conveyance of the sheet from the fixing device. A control device times a time required for detection results from the sheet detection portion to show a predetermined change, and controls a rotational speed of the motor according to the timed time.

Abstract: An image forming apparatus includes a width-information acquisition unit, an environmental-condition detecting unit, a heat roller, an end-portion-temperature-detecting unit, a first heater, a second heater, a first control unit, a first control unit, a correction-value derivation unit, an extracting unit, and a second control unit. The first heater heats a center portion of the heat roller. The second heater heats the end portion of the heat roller. The first control unit controls electric power supplied to the first heater with a first duty ratio. The correction-value derivation unit derives a correction value for the temperature condition based on an environmental condition. The extracting unit reflects the correction value for the temperature condition to extract a second duty ratio from among a plurality of second duty ratios. The second control unit controls the electric power supplied to the second heater with the data of the extracted second duty ratio.

Abstract: An image forming apparatus includes a width-information acquisition unit, an environmental-condition detecting unit, a heat roller, an end-portion-temperature-detecting unit, a first heater, a second heater, a first control unit, a first control unit, a correction-value derivation unit, an extracting unit, and a second control unit. The first heater heats a center portion of the heat roller. The second heater heats the end portion of the heat roller. The first control unit controls electric power supplied to the first heater with a first duty ratio. The correction-value derivation unit derives a correction value for the temperature condition based on an environmental condition. The extracting unit reflects the correction value for the temperature condition to extract a second duty ratio from among a plurality of second duty ratios. The second control unit controls the electric power supplied to the second heater with the data of the extracted second duty ratio.