| 摘要 |
PURPOSE:To improve the S/N by detecting whether or not an input signal has correlation such as field correlation, H correlation or frame correlation, and providing a circuit relasing the amplitude limit of a limiter only when the presence of correlation is detected. CONSTITUTION:A transistor X1 of a limiter 11 is turned off at H level of a control signal (d) incoming to a terminal 11a to limit the amplitude of a portion c1 of a signal (c), while the limiter limits the amplitude of a portion c2 of the signal (c) at L level of the control signal (e) incoming to a terminal 11b, and the amplitude limit is released during the H level. Thus, in case there is line correlation and noise having a pulse (p) exceeding a limiter level (l) of the limiter 11 is incoming, the pulse (p) is extracted from the limiter 11 as it is, the signal (a) is subtracted at a subtractor 6 by a signal decreasing the signal (f) at a subtractor 5, the noise including the pulse (p) is reduced sufficiently and a signal (g) is obtained.
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