Patent ID: 7283262

Claim:
An image forming apparatus comprising: a communication unit adapted to make communication with an external apparatus; a detection unit adapted to detect a status of said image forming apparatus, said detection unit comprising first and second detectors; a first control unit adapted to process an image to be supplied to an interface for transmission of an image signal; a second control unit adapted to control power supply to said detection unit, if the status of said image forming apparatus is to be detected in a power saving mode, said second control unit operating with power supply lower than that of said first control unit, wherein power supply to said detection unit and to said first control unit is saved when said image forming apparatus is in the power saving mode, wherein said communication unit informs the external apparatus of the status of said image forming apparatus detected by said detection unit with the power supply controlled by said second control unit in response to inquiry about the status of said image forming apparatus from the external apparatus received in the power saving mode, and wherein in the power saving mode, said second control unit executes power supply to said first detector to obtain a detection result, and switches between (a) executing power supply to said second detector to enable said second detector to detect the status of said image forming apparatus and (b) stopping power supply to said first detector without enabling said second detector to detect the status of said image forming apparatus, in response to the detection result obtained by said first detector.