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/video (A/V) apparatus comprising:

• a video signal processor which processes video data from an audio and video signal;
• a display which displays the processed video data from the video signal processor;
• an audio signal processor which processes audio data from the audio and video signal;
• an audio output port which outputs the processed audio data to a set of earphones;
• a sensor which detects whether the set of earphones is plugged into the audio output port, and detects whether the set of earphones is unplugged from the audio output port;
• a speaker which outputs sound from the processed audio data;
• at least one volume control button which controls a volume level of the speaker and a volume level of the set of earphones;
• a memory which stores a speaker volume level value, which corresponds to a volume level set by a user for the speaker, and an earphone volume level value, which corresponds to a volume level set by a user for the set of earphones;
• and
• a processor which produces a speaker volume control On-screen Display (OSD) and an earphone volume control OSD, the speaker volume control OSD and the earphone volume control OSD respectively showing the volume level of the speaker and the volume level of the set of earphones, and
• which converts the earphone volume control OSD to the speaker volume control OSD upon a detection by the sensing portion that the set of earphones is unplugged from the audio output port.