Method and apparatus for loosely synchronizing closed free running raster displays
US6195086A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Dec 23, 1997 |
| Grant date | Feb 27, 2001 |
| Priority date | — |
| Expiry date | Dec 23, 2017 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH04N7/012
- WIPO fieldAudio-visual technology
- WIPO sectorElectrical engineering
Abstract
The present invention is a means and method for synchronizing closed free-running systems, such as graphics systems, with no external synchronization signals required. Video games and most computer display controllers are closed free-running systems. Because most such systems have the means to switch between an interlaced and non-interlaced operation, and because interlaced and non-interlaced modes have a relative timing variation, the timing between two or more such closed free-running systems can be synchronized. This method allows synchronization with an imprecise timing reference. The vertical display timing is the free-running oscillator and the interlaced/non-interlaced mode transition is used as the timing adjustment means. The actual arrival time of data in a communication medium connecting two systems being synchronized is used in relation to an expected arrival time to provide the clock reference.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.