Patent ID: 7340626

Claim:
An image forming apparatus, comprising: a main power supply section as a power source operative in a normal operation mode; an auxiliary power supply section as a power source operative in a power-saving operation mode where the apparatus stands by with reduced power consumption; a plurality of sensors each changing output level thereof upon detection of a user's preparatory operation for an image forming process; and a power supply control section for switching the apparatus from the normal operation mode to the power-saving operation mode after a predetermined time period during which no image forming process is performed, the power supply control section switching the apparatus back to the normal operation mode upon detection of a change in output level of either one of the plurality of sensors in the power-saving operation mode, wherein the plurality of sensors are connected to the auxiliary power supply section through the power supply control section; and wherein the power supply control section connects part of the plurality of sensors sequentially to the auxiliary power supply section in such a manner that the plurality of sensors are intermittently activated by the auxiliary power supply section in the power-saving operation mode.