Patent ID: 8364994

Claim:
An image forming apparatus comprising: a volatile memory; and a System-On-Chip (SoC) part to operate using the volatile memory in a normal mode, to copy and use information stored to the volatile memory to an internal memory by switching to power saving modes by stages according to input status of an external signal, and reactivating the volatile memory when returning to the normal mode, wherein the SoC part comprises the internal memory; a central processing unit (CPU) to access the volatile memory in the normal mode; an interface part to receive the external signal; and a control part to, when the interface part has no input during a first preset time, copy information stored to the volatile memory to the internal memory and to convert to a first power saving mode to lower an operating frequency of the volatile memory and an operating frequency of the CPU, and when a normal mode switch signal is not input during a second preset time in the first power saving mode, to control the CPU to access the information copied to the internal memory and to convert to a second power saving mode to change the volatile memory to a self-refresh mode.