Patent ID: 9736328
Date: 2017-08-15
CPC Classifications: G06F,H04N

Claim:
1. An image forming apparatus having a normal mode and an energy-saving mode in which supply of electric power to previously defined supply-stop parts is stopped to consume less electric power than in the normal mode, the image forming apparatus comprising: a plurality of components which constitute the image forming apparatus and of which all or part are the supply-stop parts; a power supply which supplies electric power to the supply-stop parts in the normal mode but stops supplying electric power to the supply-stop parts in the energy-saving mode; a power supply monitoring controller which operates by being supplied with electric power from the power supply when transition to the energy-saving mode starts, the power supply monitoring controller stopping operating in the normal mode, the power supply monitoring controller, on receiving in the energy-saving mode an interrupt signal indicating occurrence of a recovery factor from an interruption signal generator, making the power supply restart supply of electric power to the supply-stop parts to make the image forming apparatus return to the normal mode; an automatic recovery signal generator which includes a circuit or a plurality of circuits and which inputs to the power supply monitoring controller an automatic recovery signal, which is a kind of the interrupt signal, after completion of the transition to the energy-saving mode; and an arithmetic processor which is one of the supply-stop parts, the arithmetic processor determining transition to the energy-saving mode on recognizing a transition condition to the energy-saving mode to be fulfilled in the normal mode, the arithmetic processor making the power supply stop supply of electric power to the respective supply-stop parts sequentially during a transition period starting at determination of the transition to the energy-saving mode and ending at completion of the transition to the energy-saving mode, the arithmetic processor, when an error occurs during the transition period, performing recovery preparation processing to input the automatic recovery signal to the power supply monitoring controller after completion of the transition to the energy-saving mode.