Television flicker preventing circuit with gamma value conversion prior to field-to-frame conversion
US4783703A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Mar 31, 1986 |
| Grant date | Nov 8, 1988 |
| Priority date | — |
| Expiry date | Mar 31, 2006 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH04N5/931
- WIPO fieldAudio-visual technology
- WIPO sectorElectrical engineering
Abstract
In a field/frame conversion system in which a field signal recorded on a track of a recording medium is repeatedly reproduced, a field signal delayed by 1/2 horizontal scanning duration and a directly provided field signal are alternately selected by a switch at each vertical scanning duration, and one of the field signals is formed by an arithmetic mean of a signal delayed by 1 horizontal scanning duration and a directly provided signal, to provide a frame signal, a flicker preventing circuit device in a field/frame conversion comprises a circuit provided in a front stage of an arithmetic mean circuit of the field/frame conversion system for bringing a gamma value of the field signal to 1, and a gamma circuit provided in a rear stage of the arithmetic mean circuit for returning the gamma value of the field signal to its original value.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.