Digital windowing for video sync separation
US7321398B2 · kind B2 · utility
Assignee
Inventor
Key dates
| Filing date | Sep 8, 2004 |
| Grant date | Jan 22, 2008 |
| Priority date | — |
| Expiry date | Mar 19, 2026 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH04N9/455
- WIPO fieldAudio-visual technology
- WIPO sectorElectrical engineering
Abstract
A processing circuit for a sync signal includes a trial circuit and a windowing circuit. The trial circuit includes a counter that generates a count value proportional to the duration between successive sync pulses. When the count value reaches a trial sync spacing count value, a trial window signal is created and the counter is reset. If a predetermined number of subsequent sync pulses occur within the trial window signal, the sync spacing count value is confirmed and stored in a sync spacing register. The windowing circuit includes a counter that generates a count value proportional to the duration between successive window signals, and compares the count value to the value stored in the sync spacing register to generate a window signal. The window signal is compared with the sync signal pass valid sync signals.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.