Horizontal scanning rate correction apparatus
US4305022A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Dec 6, 1979 |
| Grant date | Dec 8, 1981 |
| Priority date | — |
| Expiry date | Dec 6, 1999 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH04N9/24
- WIPO fieldAudio-visual technology
- WIPO sectorElectrical engineering
Abstract
A horizontal scanning rate correction apparatus for a cathode-ray tube, particularly of the beam index color cathode-ray tube type, includes a memory for storing correction values representing deviations of the horizontal scanning rate of the electron beam from a desired scanning rate at each of a plurality of horizontal sampling positions along each of a plurality of predetermined horizontal sampling lines which are substantially fewer in number than the horizontal lines along which scanning occurs. During display of a video signal, a selected one of the stored correction values is read out of the memory for each scanning position of the beam along a scanned one of the horizontal lines, with each read correction value, and a corresponding sampling line correction signal produced therefrom, representing the deviation at a corresponding horizontal sampling position on one of the sampling lines. A scanned line correction signal is then produced for each horizontal scanning position which is a function of the sampling line correction signal and of the vertical position of the respective scanned line, and the scanned line correction signal is applied to the beam deflection yoke or devi…
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.