Heating device and image forming apparatus

An image forming apparatus comprising a fixing device, the fixing device comprising:

• an endless rotational body;
• a heating member and a plurality of resistive members which are divided into a plurality of blocks, the resistive members being arranged side by side along a first direction with a gap between every two adjacent resistive members, each block comprising at least one resistive member, the heating member being provided on an inner side of the endless rotational body;
• temperature sensors which each have a film-shaped thermistor, each block having one film-shaped thermistor that has a contact region in which the film-shaped thermistor detects temperature, the contact region being inside of a width, in the first direction, of a resistive member in the block;
• and
• a pressure roller configured to face the heating member via the endless rotational body and to form a nip with the endless rotational body, the fixing device being configured to fix an image onto a sheet, wherein
• a predetermined block is adjacent in the first direction, to two blocks, the contact region of the film-shaped thermistor for the predetermined block is located closer to the one of the adjacent two blocks having a greater number of the resistive members of the two blocks adjacent to the predetermined block.