Audio/video device having a volume control function for an external audio reproduction unit by using volume control buttons of a remote controller and volume control method therefor

An audio/visual (A/V) device which processes an audio signal for an external audio reproduction unit, the A/V device comprising:

• a speaker operable to output the audio signal;
• an audio output port, which is connectable to an external audio reproduction unit and operable to output the audio signal to the external audio reproduction unit;
• an audio signal processing unit operable to process the audio signal and output the processed audio signal to one of the speaker and the audio output port;
• a display screen operable to display one of a first On-screen Display (OSD) window, which indicates that the external audio reproduction unit is connected to the audio output port, and a second OSD window, which indicates that the external audio reproduction unit is not connected to the audio output port;
• and
• a control unit which is operable to receive an input command and which controls the audio signal processing unit and the display screen,
• wherein if the control unit receives the input command and the external audio reproduction unit is connected to the audio output port, the control unit controls the display screen to automatically display the first OSD window, and
• wherein if the control unit receives the input command and the external audio reproduction unit is not connected to the audio output port, the control unit controls the display screen to automatically display the second OSD window.

A method for controlling an audio/visual (A/V) device having an audio output port, speaker and a display screen, wherein the A/V device processes an audio signal for an external audio reproduction unit, the method comprising:

• determining whether the external audio reproduction unit is connected to the audio output port of the A/V device;
• receiving a input command;
• if the external audio reproduction unit is connected to the audio output port of the A/V device, automatically displaying on the display screen a first OSD window indicating that the external audio reproduction unit is connected to the audio output port;
• and
• if the external audio reproduction unit is not connected to the audio output port, automatically displaying on the display screen a second OSD window indicating that the external audio reproduction unit is not connected to the audio output port.