| 摘要 |
PROBLEM TO BE SOLVED: To provide a vertical synchronization signal extracting method and an apparatus therefor, which reliably avoids wrong extraction and accurately and reliably extracts a vertical synchronizing signal from a TV signal, by suppressing the circuit addition to minimum for the circuit arrangement to avoid complicating it, without increasing the entire circuit scale. SOLUTION: TV signals S1 applied to an input terminal 21 are propagated to an integrator circuit 22, using resistors and capacitors, and a signal extractor 24 slices signals from this circuit 22 by a slice voltage S3 into digital signals for extracting the long portion of a LOW level of the TV signal S1 as a vertical synchronization signals S4. The slice voltage is set and changed according to the change of the TV signal amplitude level, due to noise or copy guard signals, etc., by a controller 33 in an MCU 29.
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