Patent ID: 8736116

Claim:
An information device having a plurality of operating modes including a first operating mode in which DC power is supplied and a second operating mode in which supply of DC power is interrupted, the information device comprising: a control unit that operates by DC power supplied from an externally connected power supply device and outputs a start latch signal when the operating mode changes from the first operating mode to the second operating mode; a power switch having an input terminal connected to the power supply device, an output terminal, and an operating unit movable between a connection on state and a connection off state, the power switch configured to hold a current connection state until the operating unit is operated; a smoothing capacitor having a first terminal connected to the output terminal of the power switch and a second terminal connected to ground; a switch circuit, connected to the output terminal of the power switch, that operates in response to a switch control signal, the switch circuit being in an open position in which the supply of DC power to the control unit is cut off when a switch control signal is input to the switch circuit and in a closed position when the switch control signal is not input to the switch circuit; an unlatch signal generating unit that detects the connection state of the power switch, and when the connection state is off, outputs an unlatch signal, the unlatch signal generating unit being capable of operating on DC power supplied from the output terminal of the power switch or from the smoothing capacitor; and a switch control signal generator configured to receive the start latch signal and the unlatch signal, and further configured to selectively generate the switch control signal based on at least whether or not the unlatch signal is received.