Convergence distortion correction method and apparatus for color cathode-ray tube
US4401922A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Jun 24, 1982 |
| Grant date | Aug 30, 1983 |
| Priority date | — |
| Expiry date | Jun 24, 2002 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH04N9/28
- WIPO fieldAudio-visual technology
- WIPO sectorElectrical engineering
Abstract
In a convergence distortion correction method and apparatus for raster-scanned color CRT having a dynamic convergence magnet assembly, the CRT display screen is divided into a plurality of zones. A digital memory is provided with a data storage field and a flag bit field at each address. Addresses of the zones are generated by means of a sync signal regenerated from an input video signal. First, the addresses of zones to be subjected to the adjustment of convergence distortion are selected to set flags in the flag bit fields of the digital memory at its addresses specified by the selected zone addresses. Then, by referring to the flags, guide patterns are displayed on the selected zones and are used to adjust the convergence distortions in those zones. Preferably, one of the displayed guide patterns is flickered. Correction data based on the results of the adjustment are stored in the data storage fields of the digital memory at the corresponding addresses. Correction data for zones other than the selected zones may be interpolated from the correction data for the selected zones.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.