Suppression of flicker effects in a television receiver
US4947251A · kind A · utility
Assignee
Inventor
Key dates
| Filing date | Nov 29, 1988 |
| Grant date | Aug 7, 1990 |
| Priority date | — |
| Expiry date | Nov 29, 2008 |
Classification
- Technology area (CPC Y)Emerging Cross-Sectional Technologies
- CPC primaryY10S348/91
- WIPO fieldAudio-visual technology
- WIPO sectorElectrical engineering
Abstract
A received video signal, in which a complete picture is made up of two line-interlaced picture fields that are successively transmitted, is converted in two different ways into respective video signals of the same vertical scan frequency in which a full complement of television lines is provided in each vertical scan interval. In a first conversion favorable to picture contents in which there is considerable motion, there are added, to the lines of one picture field of the received signal, a set of interpolated lines derived from the lines of that field. In a second conversion designed to avoid flicker at horizontal edges in the picture, the lines of two successive picture fields of the received signal are used to make up a full complement of lines. Both conversions involve time-compressing the lines so that a full complement of lines can be transmitted in a vertical scan interval. An edge detector which provides an edge signal when successive lines of a field of the received signal show a certain degree of consistent contrast are used to control a fading circuit which makes the second conversion dominant when an edge is detected and allowing the first conversion to be provided to …
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.