Image Forming Apparatus and Image Forming Method

An image forming apparatus, comprising:

• a heating member configured to fix a developer image on a sheet;
• a heat source configured to heat the heating member;
• a temperature sensor configured to acquire a temperature of the heating member;
• a switching circuit configured to supply a current to the heat source by switching a voltage inputted from an alternating-current power source between an energization state and a non-energization state;
• and
• a controller configured to execute:
• print processing of fixing the developer image on the sheet;
• first energization processing of supplying the current to the heat source after a printing command is received and before the print processing is started;
• and
• second energization processing of setting a duty ratio of an output current of the switching circuit based on a detection result of the temperature sensor so that the heating member has a fixing temperature and supplying the current to the heat source, in the print processing,
• wherein, in a case that the first energization processing is started, the controller is configured to set an energization pattern based on an end-time duty ratio which is a duty ratio when the second energization processing executed last time is ended, and elapsed time which has elapsed after the second energization processing executed last time is ended.