Patent ID: 6166776
Filing Date: 2000-12-26
Classification: H04N

Abstract:
A multi-receiving demodulator for demodulating signals received from multiple broadcasting systems, comprising:a tuner for tuning to a predetermined frequency from a received radio frequency signal and mixing the tuned predetermined frequency with a local oscillation frequency to generate an intermediate frequency;a first band pass filter for band pass filtering the intermediate frequency generated by said tuner to provide a color subcarrier corresponding to a broadcasting system of the received signal, in accordance with a first control signal;a second band pass filter for band-pass-filtering the intermediate frequency generated by said tuner to provide an audio carrier corresponding to the broadcasting system of the received signal, in accordance with a second control signal;video demodulating means for receiving the color subcarrier provided by said first band pass filter and demodulating a video signal corresponding to the broadcasting system of the received signal, in accordance with the second control signal;audio demodulating means for receiving the audio carrier provided by said second band pass filter and demodulating an audio signal corresponding to the broadcasting system of the received signal, in accordance with the second control signal; andcontrolling means for detecting a frequency of a power source which supplies power to the multi-receiving demodulator and channel selection data, and applying the first and second control signals to said first and second band pass filters and said video and audio demodulating means in accordance with the detected frequency of the power source and channel selection data.