Patent ID: 8397086

Claim:
An electronic device comprising: a power supply circuit having a continuous output terminal that continuously supplies a first power supply voltage while the electronic device is connected to a commercial power supply, and a controlled output terminal that selectively supplies a second power supply voltage according to a power supply output control signal, the controlled output terminal supplying the second power supply voltage in response to the power supply output control signal being at a first level, the controlled output terminal shutting off the second power supply voltage in response to the power supply output control signal being at a second level that is different from the first level; a load circuit configured to operate using the second power supply voltage supplied from the controlled output terminal of the power supply circuit as an operating voltage of the load circuit; a main device configured to control the load circuit, the main device having a built-in power supply controlling microprocessor that is configured to operate using the first power supply voltage supplied from the continuous output terminal of the power supply circuit as an operating voltage of the power supply controlling microprocessor; a memory configured to store a program that is processed by the power supply controlling microprocessor; and a holding circuit configured to temporarily hold the power supply output control signal at the first level until a predetermined time period elapses after the commercial power supply is connected to the power supply circuit such that the power supply circuit supplies the second power supply voltage from the controlled output terminal until the power supply controlling microprocessor loads the program from the memory and starts up, with the predetermined time period being longer than a time period over which the power supply controlling microprocessor loads the program from the memory and starts up, the holding circuit being further configured to stop holding the power supply output control signal at the first level automatically in response to the predetermined time period elapsing after the commercial power supply is connected to the power supply circuit such that the controlled output terminal of the power supply circuit shuts off the second power supply voltage.