Image forming apparatus and fixing operation control method

A fixing operation control method applied to an image forming apparatus that includes:

• a conveying portion configured to convey a sheet on which an image is to be formed;
• a heat transfer portion configured to transfer heat to the sheet conveyed by the conveying portion to heat the sheet;
• and a heating portion configured to raise a temperature of the heat transfer portion, the fixing operation control method comprising:
• a first step of, under the condition that a first print job has been input, controlling the heating portion so that the temperature of the heat transfer portion is a first target temperature, and also controlling the conveying portion so that a conveying speed of the sheet is a first speed;
• and
• a second step of, when a second print job input after the first print job has satisfied a predetermined condition, controlling the heating portion so that the temperature of the heat transfer portion is a second target temperature which is higher than the first target temperature, and also controlling the conveying portion so that the conveying speed of the sheet is a second speed which is faster than the first speed;
• a third step of, when a first print job is input in a state where the image forming apparatus is in a power saving mode, transitioning from the power saving mode to a print mode in which printing on the sheet is possible, and controlling the heating portion so that the temperature of the heat transfer portion is the first target temperature, and also controlling the conveying portion so that the conveying speed of the sheet is the first speed;
• a fourth step of, in the print mode, when the number of sheets represented by the second print job input after the first print job is equal to or greater than a predetermined setting number, controlling the heating portion so that the temperature of the heat transfer portion is the second target temperature, and also controlling the conveying portion so that the conveying speed of the sheet is the second speed;
• and
• a fifth step of, when, after the first print job, a plurality of print jobs including the second print job in which the number of sheets is less than the predetermined setting number have been continuously input, maintaining the temperature of the heat transfer portion at the first target temperature and maintaining the conveying speed of the sheet at the first speed if a total number of sheets to be printed by the plurality of print jobs is less than the predetermined setting number, and controlling the heating portion so that the temperature of the heat transfer portion is the second target temperature and controlling the conveying portion so that the conveying speed of the sheet is the second speed if the total number of sheets to be printed by the plurality of print jobs is equal to or greater than the predetermined setting number.