Patent attributes
To provide an image processing apparatus that can reduce power consumption as compared to a conventional case by energizing required minimum devices at an appropriate timing depending on contents of a request received from an external apparatus through a communicating medium during a power-saving state, if a data processing request is received from the external apparatus through a NIC during a sleep mode, an MPU of the NIC and an MPU of each controlling unit control automatic changeover switches, which switch energization states of sub-power sources, to control energization of each function block based on contents of the data processing request and the state of the own apparatus. When switching the function blocks from a “non-energized state” to an “energized state”, a hierarchical energization controlling process is performed to switch the functional blocks with hierarchical relationships to the “energized state” in the order from higher to lower blocks.