Heater including a heating wire having a zig-zag shape, and a fixing device, an image formation device, and a heating device with such a heater

A heater in which a plurality of heat-generating cells partitioned by a virtual boundary line are arranged side by side on a base body, the heater configured to heat an object-to-be-heated in a state of facing the base body, the heater comprising:

• the base body;
• and
• one resistive heating wire formed in each of the heat-generating cells and having a zig-zag shape as a whole, the resistive heating wire being formed by connecting a parallel wiring in which a plurality of wirings are formed in parallel and a turn-back wiring formed so as to turn back the parallel wiring in a vicinity of the boundary line between adjacent ones of the heat-generating cells;
• wherein
• in the adjacent ones of the heat-generating cells, the resistive heating wire of one of the heat-generating cells has an extension portion formed so as to extend the parallel wiring past the boundary line, and the resistive heating wire of the other of the heat-generating cells is shortened or deformed so that a wiring of a portion facing the extension portion maintains an electrical insulation with the extension portion;
• and
• the resistive heating wires of the adjacent ones of the heat-generating cells include the extension portions alternately along the boundary line such that a periphery of the extension portion of the one of the adjacent heat-generating cells is surrounded by peripheries of the extension portions of the other of the heat-generating cells along the boundary line.