Patent ID: 7966501

Claim:
A multi-function peripheral comprising: a multi-function peripheral unit configured to have plural functions including a copy function; a power supply unit configured to be connected to a commercial power supply as a main power supply for the multi-function peripheral unit; an electrical storage device charged in advance as an auxiliary power supply for the multi-function peripheral unit; and a control circuit that monitors a load current flowing to the multi-function peripheral unit, supplies electric power from the electrical storage device to the multi-function peripheral unit instead of electric power from the power supply unit when the load current is smaller than a threshold set as an allowable lower limit of power efficiency of the power supply unit, and supplies the electric power from the power supply unit to the multi-function peripheral unit when the load current increases to be equal to or larger than the threshold, the control circuit controlling the electric storage device to be charged in a copy state when the load current is equal to or larger than the threshold and is smaller than a maximum value of the load current flowing to the multi-function peripheral unit.