Patent ID: 7537163

Claim:
An image forming apparatus having a communication interface which mediates data communication, the image forming apparatus receiving image data through the communication interface to form an image based on the received image data, the image forming apparatus comprising: a power supply unit which supplies electric power in any one of power supply modes of an operation mode in which the electric power necessary to form the image is supplied, and a power saving mode in which stand-by electric power is supplied; a states monitor unit which monitors a connection state and a non-connection state of the communication interface; and a mode switch unit which switches the power supply unit to the operation mode, in response to detection by the states monitor unit of either of a change from the non-connection state to the connection state or a change from the connection state to the non-connection state, when the power supply unit is in the power saving mode, wherein the mode switch unit holds the power supply unit in the operation mode even when the states monitor unit detects the change from the connection state to the non-connection state after detecting the change from the non-connection state to the connection state.