Heating member, fixing device, and image forming apparatus

A heating member for heating a fixing member, the heating member comprising:

• a plurality of heat generation blocks, each of which generating heat when being energized, wherein:
• the plurality of heat generation blocks is provided side by side along a width direction that is orthogonal to a conveyance direction of a recording medium,
• a length of at least one of the plurality of heat generation blocks in the width direction is equal to, or shorter than, a minimum difference of a length in the width direction between recording media, including the recording medium, in adjacent standard sizes in an order of length in the width direction among the recording media to be conveyed in a plurality of types of standard sizes,
• each of the plurality of heat generation blocks has a positive temperature coefficient, and
• among the plurality of heat generation blocks, a first heat generation block and a second heat generation block, different from the first heat generation block, are provided, such that:
• the first heat generation block corresponds to an area passed by the recording medium in a minimum size having a shortest length in the width direction of the recording media in the plurality of types of the standard sizes, and
• a Curie temperature of the second heat generation block is higher than a Curie temperature of the first heat generation block.