Clock signal generator providing non-symmetrical alternating phase intervals
US4122478A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Jan 28, 1977 |
| Grant date | Oct 24, 1978 |
| Priority date | — |
| Expiry date | Jan 28, 1997 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG11B2220/20
- WIPO fieldAudio-visual technology
- WIPO sectorElectrical engineering
Abstract
Apparatus is disclosed for providing a square wave output signal for use in alternating the phase of a sampling clock signal on successive video lines of a video signal having a horizontal blanking interval at the beginning of each video line and a burst of cycles of chrominance subcarrier in each of said horizontal blanking intervals. The square wave output signal changes between first and second levels during alternate video lines, but the signal is always maintained at one of said levels during the occurrence of the bursts of cycles. The square wave signal controls the sampling clock signal generator so that the clock signal is of a first phase while the square wave signal is at the first level and of an opposite phase while the square wave signal is at the second level.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.