Patent ID: 8983314
Filing Date: 2015-03-17
Classification: G03G

Abstract:
1. An image forming apparatus comprising: an image forming section configured to form a toner image on a sheet; a heater configured to be supplied with AC electrical power from an AC power source so as to thermally fix the image formed by said image forming section on the sheet; a first relay configured to be connected between the AC power source and one end of said heater; a second relay configured to be connected between the AC power source and another end of said heater; a voltage detection circuit, which is provided in a stage subsequent to said first and second relays and is connected in parallel to said heater, configured to detect the presence or absence of inputting AC voltage into said heater; and a relay control unit configured to output relay control signals for turning on and off respective ones of said first relay and said second relay and configured to output heater control signals for switching on or off said heater, wherein said relay control unit outputs the relay control signals for turning on said first relay and turning off said second relay before switching on said heater according to the heater control signals, and then outputs the relay control signals for turning on said second relay if said voltage detection circuit does not detect inputting the AC voltage and determines that said second relay has failed if said voltage detection circuit detects inputting the AC voltage and said relay control unit outputs the relay control signals for turning off said first relay and turning on said second relay before switching off said heater, and then outputs the relay control signals for turning off said second relay if said voltage detection circuit does not detect inputting the AC voltage and determines that said first relay has failed if said voltage detection circuit detects inputting the AC voltage.