| 摘要 |
PURPOSE:To detect a dropout with a most suitable condition and without any malfunction for either a ordinary reproduction or high-speed reproduction by comparing the level of a reproducing video signal with a second reference level which is higher than a first reference level, and modifying the reference frequency of the dropout detector based on the output of said comparison. CONSTITUTION:The dropout detection circuit 14' is composed of a first level comparator 10, the dropout detector 19, and a second level comparator 18. The level comparator 10 compares the level of a frequency modulated composite color video signal from a reproduction equalizing circuit 15 with the first reference level, and the detector 19 compares the period of comparison output from the level comparator 10 with the reference period, and thus a dropout is detected. The level comparator 18 compares the level of the frequency modulated composite color video signal with a second reference level higher than a first reference level. The reference period for the dropout detector 19 is modified based on a comparison output from the level comparator 18.
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