Method to synchronize video modulation using a constant time base
US5404173A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Mar 10, 1993 |
| Grant date | Apr 4, 1995 |
| Priority date | — |
| Expiry date | Mar 10, 2013 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG09G5/12
- WIPO fieldAudio-visual technology
- WIPO sectorElectrical engineering
Abstract
Successive pixels representing video data in successive lines in a raster scan are buffered. Each of the lines has a sync pulse defining the line beginning. A phase adjustment is determined between the sync pulse, preferably at a particular level in the sync pulse, and an adjacent one of system adjacent clock signals at a particular frequency. The actual or expected phase adjustment between the pixels at the end of each line is also determined. The difference between the phase adjustments at the beginning and end of each line is then determined. Progressive adjustments are made in the phase of each successive pixel in the line relative to the system clock signals in accordance with the number of system clock signals in the line and the determined difference in the phase adjustment between the line beginning and end. In this way, the pixels of video data are synchronized with the system clock signals. When the actual phase adjustment relative to the system clock signals is determined at the end of each line, the difference in the phase adjustments at the beginning and end of such line is determined from the phase adjustment for such line and the phase adjustment stored for the previ…
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.