Image forming apparatus having a first circuit for supplying power to a heater, a second circuit electrically insulated with reinforced insulation from the first circuit, and a third circuit electrically insulated from the first and second circuits

An image forming apparatus for forming a toner image on a recording material, comprising:

• a fixing unit which has a heater for generating heat according to power supplied from an AC power supply and thermally fixes the toner image formed on the recording material onto the recording material;
• and
• a circuit board provided with a power control circuit for controlling power supplied to the heater,
• wherein a circuit including both a circuit within the fixing unit and the power control circuit is provided with a first circuit which supplies power to the heater from the AC power supply, a second circuit electrically insulated with reinforced insulation from the first circuit, and a third circuit electrically insulated from both the first circuit and the second circuit,
• wherein all of the first to third circuits are provided on at least one surface of the circuit board, and
• wherein the first to third circuits are disposed on at least one straight line on which all of the first to third circuits are present on the one surface of the circuit board in the order of the first circuit, the third circuit, and the second circuit.