Image forming apparatus and fixing device used therein

Claim 1

A main body of an image forming apparatus to which a heat fixing device is attached, the heat fixing device having a heat generating part which has an electric heat generation member for generating heat by electrifying and a temperature detection device for detecting a temperature of the heat generating part, the heat fixing device heating and fixing an unfixed toner image onto a recording medium, the main body of the image forming apparatus having an image forming part which forms the unfixed toner image in the recording medium, said main body comprising: a control part which controls electric power supplied to the electric heat generation member; an electric power supply cut-off circuit which cuts off electric power supply to the electric heat generation member; and a determination circuit which causes the electric power supply cut-off circuit to be in a cut-off state by determining whether output of the temperature detection device indicates a predetermined anomaly, wherein the heat fixing device and the main body of the image forming apparatus are electrically connected to each other with a connector, the temperature detection device and the determination circuit are connected through the connector, power supply voltage is supplied to the temperature detection device via a jumper cable connected to the connector from the main body of the image forming apparatus while passing through a path detouring to the heat fixing device side, and the determination circuit causes the electric power supply cut-off circuit to be cut off, when the power supply voltage is not supplied to the temperature detection device because the connector is in a disconnected state.