Patent ID: 8635474

Claim:
An image forming apparatus comprising: a first control unit configured to control an operation of an image forming unit; and a second control unit configured to transmit information for forming an image to the first control unit, the image forming apparatus having a normal operation mode in which an image forming operation is performed, a first power-saving operation mode in which an operation of the first control unit is stopped, and a second power-saving operation mode in which supplying of electric power to the second control unit is stopped, the image forming apparatus further comprising: a power supply unit configured to supply electric power to the image forming apparatus; a state detection unit configured to detect a state of the image forming unit; and a connection detection unit configured to detect whether an external device is connected to the image forming apparatus, the second control unit being configured such that when the image forming apparatus is in the first power-saving operation mode, the second control unit determines whether the image forming apparatus is to switch into the normal operation mode from the first power-saving operation mode in response to a signal from the power supply unit, a signal from the state detection unit, or a return signal from the second control unit, the first control unit being configured such that when the image forming apparatus is in the second power-saving operation mode, the first control unit determines whether the image forming apparatus is to switch into the normal operation mode from the second power-saving operation mode in response to the signal from the power supply unit or the signal from the state detection unit, the first control unit being configured such that when the image forming apparatus is in the second power-saving operation mode, the first control unit determines whether the image forming apparatus is to switch into the normal operation mode or the first power-saving operation mode from the second power-saving operation mode in response to a signal from the connection detection unit.