Patent ID: 7593661
Filing Date: 2009-09-22
Classification: G03G

Abstract:
1. A power-saving control method of an image forming device which is adapted for being set in a power saving state in which power supply to all function units in a main control function unit, except a main control unit which controls the whole image forming device, is stopped, comprising steps of: setting the image forming device in the power saving state when an input operation is not performed by a user over a predetermined time; shifting the image forming device from the power saving state to a minimum power state in which power supply to the main control unit is stopped; activating, prior to shifting of the image forming device to the minimum power state, a filtering unit receiving a power supply separate from a power supply to the main control function unit, so that the filtering unit detects communication between an external device and the image forming device in the minimum power state; determining whether a communication signal detected by the filtering unit in the minimum power state indicates an image formation request from the external device; and causing, when the communication signal indicates the image formation request, the image forming device to return from the minimum power state through the power saving state to a standby state, so that the image forming device is ready for performing image formation.