Patent ID: 7743187

Claim:
An audio system which accommodates an external device, comprising: an adapter having an external device connector at one terminal and a USB connector at another terminal to provide a signal connection therebetween, the external device connector being provided for connection to the external device; and an audio device which includes: a USB connector which provides an interface to an external device connected either directly thereto or through the adapter; a multiplexer which establishes a signal path to the USB connecter by either a USB signal line or a serial signal line corresponding to a selection control signal; a USB controller, connected to the external device through the USB signal line, which decodes a digital audio file received from the external device so as to output a sound; a serial controller, connected to the external device via the adapter through the serial signal line, which receives song information through the serial signal line so as to provide the external device with a device control signal based on a user operation; and an audio controller which provides the multiplexer with the selection control signal based on a device identification when the external device is connected via the USB connector, moves the digital audio file from the external device through the USB controller in the case that the external device is a USB device, receives the song information from the external device through the serial controller and provides the device control signal to the external device so as to let the external device be driven in response to the device control signal in the case that the external device is not a USB device.