Patent ID: 7706542

Claim:
A noise removal device for removing a noise mixed in a signal, said device comprising: first noise extracting means for extracting a noise currently mixed in a first input signal and outputting the noise as a first noise signal; second noise extracting means for extracting a noise currently mixed in a second input signal and outputting the noise as a second noise signal; second noise smoothing means for smoothing the second noise signal to generate a second noise-smoothed signal; noise hold control signal generating means which takes the second noise-smoothed signal as a threshold value and compares the second noise signal with the threshold value to detect an occurring position and an occurring period of the second noise signal and to generate a noise hold control signal having a hold period corresponding to a result of the detection; noise hold means for holding the first noise signal in accordance with the noise hold control signal to generate and thus output a held noise signal; first noise smoothing means for smoothing the held noise signal to generate a first noise-smoothed signal; hold control signal generating means which takes the first noise-smoothed signal as a threshold value and compares the first noise signal with the threshold value to detect an occurring position and an occurring period of the first noise signal and to generate a second noise hold control signal having a hold period corresponding to a result of the detection; and hold means for holding the first input signal in accordance with the second noise hold control signal to generate and thus output the first input signal not containing any noise.