Patent ID: 8358943

Claim:
An electric power relaying unit of an image forming apparatus which transmits an alternating current electric power output from an external power supply to an image forming apparatus main body, the electric power relaying unit of the image forming apparatus comprising: an electric power input unit which is connected to the external power supply, and receives an alternating current electric power from the external power supply; an electric power output unit which is connected to an electric power input terminal of the image forming apparatus main body, and outputs the input alternating current electric power to the image forming apparatus main body; and an electric power blocking unit which selectively blocks the alternating current electric power output from the electric power input unit to be input to the electric power output unit, the electric power blocking unit comprising a switching unit which switches an input of the alternating current electric power with respect to the electric power output unit; an electric power detecting unit which detects an electric power property of the alternating current electric power; a memory unit in which a predetermined electric power property information is stored, the memory unit storing a profile of a predetermined abnormal electric power pattern; a control unit which compares an electric power property detected by the electric power detecting unit with an electric power property information stored in the memory unit, and controls a switching operation of the switching unit if determining that the detected electric power property corresponds to a predetermined electric power property in a failure of the image forming apparatus main body from a comparison result; and an interface unit which is provided to be accessible to the memory unit from an outside so that the profile of the electric power pattern stored in the memory unit can be updated.