Method and apparatus for improving the sharpness of a video picture
US4322742A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Nov 28, 1977 |
| Grant date | Mar 30, 1982 |
| Priority date | — |
| Expiry date | Nov 28, 1997 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH04N3/32
- WIPO fieldAudio-visual technology
- WIPO sectorElectrical engineering
Abstract
A method and apparatus for improving the sharpness of a video picture displayed on the screen of a cathode ray tube. At least one electron beam scans the screen in line-scanning and vertical directions, respectively, the electron beam having its intensity modulated in accordance with a video signal. The scanning velocity of the electron beam is modulated in the line-scanning direction in accordance with transitions of the video signal which correspond to transitions between high and low brightness levels of the displayed video picture. Each electron beam is shaped to have a substantially oval shape whose longer axis is disposed in the line-scanning direction and whose shorter axis is disposed in the vertical direction, whereby the oval-shaped beam impinges upon the display screen and the sharpness of the displayed video picture in the vertical direction is improved.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.