Synchronization method and apparatus
US4772966A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Oct 5, 1984 |
| Grant date | Sep 20, 1988 |
| Priority date | — |
| Expiry date | Oct 5, 2004 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG11B2220/90
- WIPO fieldAudio-visual technology
- WIPO sectorElectrical engineering
Abstract
A synchronizer for synchronizing a slave tape recorder to a master tape recorder. When the speed of the master recorder exceeds 2.5 times the nominal play speed, the synchronizer causes the slave recorder to lag behind the master recorder by an amount related to the speed of the slave recorder. At lower speeds, the synchronizer causes the slave recorder to lock onto the position and speed of the master recorder. The synchronizer employs time-code readers to read time-code on address tracks on the master and slave recorders. The time-code readers produce not only time-code but also clock pulses which are employed to determine the speed of master and slave with high resolution. Both the time-code readers and a resolver employed in the synchronizer are constructed from gate assemblies rather than processors to reduce execution times for the processor in the synchronizer. The resolver is a digital resolver which includes a phase comparator which produces pulses having a width related to the phase difference between indications of the synchronization word in the time-code and polarity to indicate whether the master leads or lags the slave. This signal is applied to a counter which gener…
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.