Patent ID: 7890784

Claim:
A power supplying mode switching controller, comprising: a main controller which controls an image forming apparatus; a sub power supply circuit which has a normal mode for supplying an operating voltage to the image forming apparatus including the main controller, and a power saving mode for cutting off the operating voltage to a part of the image forming apparatus including the main controller; an I/O controller which causes the sub power supply circuit to switch to the normal mode when a factor for returning to the normal mode is generated in the power saving mode of the sub power supply circuit; and a detachable recording medium interface to which a detachable recording medium is attached in the I/O controller, wherein the I/O controller includes a first attaching change detecting circuit which detects an attaching change of the detachable recording medium to the detachable recording medium interface; and when the first attaching change detecting circuit detects the attaching change of the detachable recording medium to the detachable recording medium interface in the power saving mode, the I/O controller switches the sub power supply circuit to the normal mode and informs the main controller of the attaching change of the detachable recording medium, and the main controller renews information in a memory to be attaching change information.