Reference time detecting circuit
US4621288A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Jun 20, 1983 |
| Grant date | Nov 4, 1986 |
| Priority date | — |
| Expiry date | Jun 20, 2003 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH04N5/10
- WIPO fieldAudio-visual technology
- WIPO sectorElectrical engineering
Abstract
A reference time detecting circuit for detecting a predetermined transit of a synchronizing signal taken as a reference time of a video signal detects the reference time by using a masking pulse including the predetermined transit and the video signal. The level for detecting the transit is set at a side over a half level of the synchronizing signal level, and a detecting signal and the masking pulse are supplied to a flip-flop circuit (60) from which an output signal is derived. Since the level for detecting the transit is set at the side over the half level of the synchronizing signal level, the reference time can be detected by a first pulse in a range of the masking pulse. Furthermore, since this signal and the masking pulse are supplied to the flip-flop circuit (60), a reference time signal can be formed quite easily.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.