| 摘要 |
PURPOSE:To prevent deterioration of picture quality due to impulse noise by providing a subtraction means for obtaining a difference signal between the input and output of a delay means and a detection means for comparing a level of a video signal portion of an output signal of the subtraction means and a reference level to obtain an output judging the presence of the impulse noise. CONSTITUTION:A FM demodulation signal 102 is given to a 1-horizontal period delay device 2, one input terminal (a) of a switch 3, a positive polasity input of a subtractor circuit 4 and an impulse noise detector 5 respectively. When no impulse noise is detected the impulse noise detector 5, connects a switch 3 to the position of a terminal (a) and connects the switch to the position of a terminal (b) in detecting any impulse noise. Thus, the switch 3 selects a video signal before one horizontal period if any impulse noise takes place and gives the existing video signal not including noise to an output terminal 6 thereby leading out a video signal free from noise at all times.
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