JP2008191372A5 - - Google Patents

Claims (2)

An image forming unit for forming an image on a recording material;
An endless film; a heater that contacts the inner surface of the endless film; a pressure roller that forms a fixing nip portion with the heater via the endless film; a pressure mechanism that applies pressure to the fixing nip portion; A pressure release mechanism that acts on a pressure mechanism to release pressure applied to the fixing nip portion, and a relay provided in a power supply path from an AC power source to the heater, and A fixing unit that heats and fixes the image to the recording material while sandwiching and conveying the recording material to be carried;
In an image forming apparatus having
When having a failure detection means for detecting a failure of the relay, and when the failure detection means detects the failure of the relay at the timing of releasing the pressure applied to the fixing nip portion by operating the pressure release mechanism, An image forming apparatus, wherein the pressure release mechanism is not operated . The device is further provided in a line on the opposite side of the power supply path from the line in which the relay is provided, and the triac is controlled so that the heater maintains a target temperature. A DC / DC converter connected to the rectifier diode bridge and a rectifier diode bridge that rectifies the AC waveform of the AC power source by branching from the power supply path on the AC power source side, and the failure detection means has one end 2. The frequency detection circuit according to claim 1, further comprising: a frequency detection circuit connected to the power supply path on the heater side of the relay and having the other end connected between the rectifier diode bridge and the DC / DC converter. the image forming apparatus.