| 摘要 |
<p>A vide signal synchronization extraction device includes detector means with two thresholds (19, 20, 24, 25), for detecting the synchronization pulses, a first threshold for detecting the leading edge, a second threshold for detecting the trailing edge of the same pulse. Said thresholds are defined, for instance, by means of an amplitude detector (21) for the synchronization pulses. The device of the invention comprises sample-and-hold means (27) which is used, when a synchronization pulse is detected, for bringing back the voltage stored by said amplitude detector in a memory device (22), to the voltage level corresponding to this synchronization pulse. The invention is useful for extracting synchronization signals from a video signal.</p> |
