Patent attributes
An image forming apparatus according to an aspect of the invention is operable in a first mode in which a first unit group comprising at least one of a plurality of functional units is activated and a second mode in which a second unit group comprising at least one of the plurality of functional units is activated. In the first mode, a control unit is operable to: activate a first power source circuit; input a first voltage to a third power source circuit; and supply an operation voltage converted by the third power source circuit to the first unit group. In the second mode, the control unit is operable to: activate a second power source circuit and deactivate the first power source circuit; and supply a second voltage output from the second power source circuit to the second unit group without intervention of the third power source circuit.