Patent ID: 8322609

Claim:
An image forming apparatus which includes a plurality of components, the image forming apparatus comprising: a power supply unit configured to supply power to the plurality of components, wherein the power supply unit includes a first power mode and a second power mode, wherein the second power mode supplies less power than the first power mode; a control unit configured to control which power mode the power supply unit is to use; a first authentication unit, to which power is supplied from the power supply unit while in the second power mode, wherein the first authentication unit performs a first user authentication when an authentication request has been received in the second power mode; and a sending unit configured to send a request signal to request the control unit to shift the power supply unit to the first power mode when the first authentication unit has succeeded in the first user authentication, wherein the image forming apparatus is connected to an external authentication apparatus, and wherein the control unit controls the power supply unit to shift from the second power mode to the first power mode upon receipt of the request signal and causes the external authentication apparatus to perform a second user authentication.