Patent ID: 8250387

Claim:
A method comprising: placing a portable computer in an non-operating state, wherein said portable computer includes a start-up button, a proximity sensor, a biometric authentication device, a power supply unit containing a first power system and a second power system capable of having less power loss than said first power system in a light-load condition; deactivating said second power system so that electric power is supplied from said first power system to said biometric authentication device during said non-operating state of said portable computer; in response to said proximity sensor's detection of a person being proximate to said biometric authentication device, activating said second power system so that electric power is supplied from said second power system to said biometric authentication device during said non-operating state of said portable computer; performing an authentication operation while receiving electric power from said second power system during said non-operating state of said portable computer; and in response to said authentication operation being a success, starting up said portable computer by causing said portable computer to transition from said non-operating state to a power-on state.