Method and apparatus for providing a timing signal with high frequency accuracy in video equipment for supporting an on-screen display in the absence of a video signal
US6556250B1 · kind B1 · utility
Assignee
Inventors
Key dates
| Filing date | Aug 10, 1999 |
| Grant date | Apr 29, 2003 |
| Priority date | — |
| Expiry date | Aug 10, 2019 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH04N5/126
- WIPO fieldAudio-visual technology
- WIPO sectorElectrical engineering
Abstract
A circuit for providing a sufficiently accurate clock signal for reconstruction of an image from a video signal can function with or without receiving an incoming video signal containing clock data. In this way, a clock signal for supporting an on-screen display can be created in the absence of an incoming video signal. Control data used to control a voltage controlled oscillator generating a clock signal is recorded when the control logic of the oscillator is locked to the timing data in an incoming video signal. In the absence of an incoming video signal, the recorded control data is retrieved and resubmitted to the control logic so that the oscillator can be made to output an appropriate clock signal even in the absence of an input video signal.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.