Digital circuit for providing a binary signal on the occurrence of a predetermined frequency ratio of two signals
US4509072A · kind A · utility
5Cited by
0References
17Claims
0Family size
Assignee
Inventors
Key dates
| Filing date | Mar 23, 1984 |
| Grant date | Apr 2, 1985 |
| Priority date | — |
| Expiry date | Mar 23, 2004 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH04N9/44
- WIPO fieldAudio-visual technology
- WIPO sectorElectrical engineering
Abstract
The invention provides a digital circuit for generating a binary signal output when a predetermined frequency ratio, v=f1/f2, of two signals F1 and F2 occurs during a selected measuring period. The circuit is particularly adapted for use in a color television receiver to determine the ratio between the chrominance-subcarrier frequency and the horizontal frequency, which ratio is fixed at the transmitting end, both in the system and the NTSC system.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.