Vertical synchronizing signal detector circuit
US4238770A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Sep 27, 1979 |
| Grant date | Dec 9, 1980 |
| Priority date | — |
| Expiry date | Sep 27, 1999 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH04N5/10
- WIPO fieldAudio-visual technology
- WIPO sectorElectrical engineering
Abstract
There is disclosed a vertical synchronizing signal detector circuit for use with a PCM recording/reproducing system which records and reproduces audio signals with pulse code modulation by the use of a home VTR system or a part thereof. The vertical synchronizing signal detector circuit comprises an input terminal for receiving a composite synchronizing signal including a horizontal synchronizing signal and a vertical synchronizing signal, an output terminal for providing a vertical synchronizing pulse synchronized with the vertical synchronizing signal, a clock pulse generator circuit connected to the input terminal and adapted to generate a clock pulse having half the period of the horizontal synchronizing signal and a phase lag therefrom of one-fourth the period thereof, a vertical synchronizing signal extractor circuit connected to the input terminal and the clock pulse generator circuit and adapted to compare the vertical synchronizing signal with a reference waveform pattern for the vertical synchronizing signal so as to generate a vertical synchronizing signal output synchronized with the vertical synchronizing signal only when the comparison results in a complete coincidenc…
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.