DROP-OUT DETECTING CIRCUIT
PURPOSE:To detect correctly a drop-out at a place near the front edge of a vertical synchronizing pulse of a video signal which causes the flicker on a screen, by producing a marker signal from a vertical synchronizing signal preceding by a cycle (a field) and using said marker signal to gate a drop...
Gespeichert in:
1. Verfasser: | |
---|---|
Format: | Patent |
Sprache: | eng |
Schlagworte: | |
Online-Zugang: | Volltext bestellen |
Tags: |
Tag hinzufügen
Keine Tags, Fügen Sie den ersten Tag hinzu!
|
Zusammenfassung: | PURPOSE:To detect correctly a drop-out at a place near the front edge of a vertical synchronizing pulse of a video signal which causes the flicker on a screen, by producing a marker signal from a vertical synchronizing signal preceding by a cycle (a field) and using said marker signal to gate a drop-out detecting signal. CONSTITUTION:A vertical synchronizing signal V.SYNC is supplied to a terminal 10 from a reproducer 1; while a drop-out pulse, i.e., a correction signal is supplied to a terminal 11 from the reproducer 1 respectively. Then the signal V. SYNC is supplied to a mask signal generating circuit 12 and a noise filter 13. The circuit 12 has the phase synchronization with the signal V.SYNC and delivers a signal having the pulse width of a period including the period of said vertical synchronizing signal, especially a place near the front edge. An output signal (b) is supplied to the filter 13, and the noise of the signal V.SYNC is eliminated through the filter 13. This prevents a malfunction of a drop-out detecting circuit. |
---|