Prompter eliminating phase shift in sub-carriers
US6104440A · kind A · utility
Assignee
Inventor
Key dates
| Filing date | Mar 4, 1997 |
| Grant date | Aug 15, 2000 |
| Priority date | — |
| Expiry date | Mar 4, 2017 |
Classification
- Technology area (CPC Y)Emerging Cross-Sectional Technologies
- CPC primaryY10S348/91
- WIPO fieldAudio-visual technology
- WIPO sectorElectrical engineering
Abstract
The image signal processing apparatus for a prompter is intended to improve ease in viewing an image when using clock frequencies synchronized to the sub-carriers of the four-field sequence. That is, the sub-carriers with different phases are separated from the video signal, in-phase clock signals from which phase shift in the sub-carriers is eliminated are generated by a timing signal generator circuit, and image data in all four fields are processed with the clock signals. This reduces flickering on the screen. The timing signal processing circuit may generate in-phase clock signals for odd fields and in-phase clock signals for even fields, and shift the phase between them by 180.degree. so that pixels in an oblique direction are obliquely aligned with half pixel shift between both clock signals. This is particularly effective for an oblique line.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.