Vertical sync separator
US5229854A · kind A · utility
Assignee
Inventor
Key dates
| Filing date | May 17, 1991 |
| Grant date | Jul 20, 1993 |
| Priority date | — |
| Expiry date | May 17, 2011 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH04N5/10
- WIPO fieldAudio-visual technology
- WIPO sectorElectrical engineering
Abstract
In a vertical sync separator, a composite sync signal in which picture information is removed is coupled via a low-pass filter to an input terminal of a comparator having a predetermined threshold level. The comparator produces an output signal when a voltage at the input terminal is more positive than the threshold level, that is indicative of the occurrence of a vertical sync pulse. When any of equalizing and horizontal sync pulses occurs, the comparator output signal is not produced. A negative current source is coupled to the low-pass filter to provide level shifting of the comparator input voltage so as to increase a guard band or noise immunity of the sync separator.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.