Fixing device, image forming apparatus, and method for adjusting length of interposing and pressurizing region by fixing device

An image forming apparatus comprising:

• a transfer unit configured to transfer a toner image onto a sheet;
• a fixing device configured to fix the toner image onto the sheet, the fixing device including:
• an endless belt,
• a pressure element configured to press against an outer side of the endless belt,
• a heating member provided on an inner side of the endless belt and configured to heat the endless belt, the heating member including:
• a heat generating element, and
• electrodes provided on both sides of the heat generating element in a sheet conveyance direction and connected to the heat generating element, and
• an adjustment mechanism configured to move at least one of the heating member and the pressure element in a manner to move the one closer to or away from the other;
• and
• a controller configured to control the adjustment mechanism so that a distance between the heating member and the pressure element becomes a first distance during a fixing process and a second distance that is larger than the first distance during temperature raising of the heating member, which is conducted before the fixing process.