Write clock pulse generator used for a time base corrector
US4613827A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Jul 24, 1985 |
| Grant date | Sep 23, 1986 |
| Priority date | — |
| Expiry date | Jul 24, 2005 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH03L7/0891
- WIPO fieldAudio-visual technology
- WIPO sectorElectrical engineering
Abstract
A write clock pulse generator is disclosed, in which a horizontal synchronizing signal is separated from an input video signal and supplied to a PLL (phase locked loop) circuit to form a first clock with the frequency of nf.sub.H (n is an integer), a color burst signal is separated from the input video signal and used to drive a gate type variable oscillator to thereby form a second clock synchronized in phase with the color burst signal and whose average frequency is nf.sub.H, a difference between the pulse widths of the clocks resulting from counting down the first and second clocks to 1/M and the frequency of the variable oscillator is controlled by the compared output therebetween, whereby to produce a second clock synchronized in phase with the color burst signal and the frequency of which is n times the horizontal synchronizing signal.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.