Fixing device and image forming apparatus including fixing device

A fixing device comprising:

• a first fixing member;
• a heating member;
• a fixing belt that forms an endless-shaped belt member supported around the first fixing member and the heating member with tension to be rotatable, and comes into contact with the heating member to be heated;
• and
• a second fixing member that forms a fixing nip region together with the fixing belt, the fixing device fixing a toner image borne on a recording medium onto the recording medium in the fixing nip region under application of heat and pressure,
• the heating member including:
• a curved heat radiating member having an outer circumferential surface in contact with the fixing belt;
• and
• a heat generating member having a heat generating layer composed of a resistance heat generating element that generates heat due to being energized and arranged to be in contact with an inside surface of the heat radiating member,
• the resistance heat generating element including:
• a paper passing region heating section forming a heat generating source part for heating a paper passing region of the fixing belt where the recording medium contacts and passes in the fixing nip region;
• and
• a detecting section that is provided to correspond to a paper non-contacting region of the recording medium of the fixing belt and connected electrically in parallel with the paper passing region heating section, and
• the fixing device further comprising an overheat preventing element that is provided in a vicinity of the detecting section and suppresses energization to the resistance heat generating element when temperature of the detecting section reaches a predetermined value.