Patent ID: 7796947

Claim:
A display system for transmitting FM signals to an external audio system having an FM reception function, the display system comprising: a tuner for receiving an RF signal and dividing the RF signal into a video signal and an audio signal; an audio processor for receiving the audio signal from the tuner; an FM detector for searching usable channels or unused channels from among FM frequency bands of a reception area and transmitting information on the unused channels; a microprocessor for setting at least one of the unused channels as an available channel, the unused channels being provided from the FM detector, and the microprocessor controlling an internal speaker of the display system to output an audio signal on the available channel; a memory for storing the available channel under control of the microprocessor; and an FM transmitter for receiving the audio signal from the audio processor and transmitting the audio signal over at least one channel selected from among the channels stored in the memory under control of the microprocessor, wherein the microprocessor can determine the available channel without interference by monitoring the audio signal on the available channel from the internal speaker.