Clamp circuit for RGB output stages
US4178610A · kind A · utility
2Cited by
5References
9Claims
0Family size
Assignee
Inventors
Key dates
| Filing date | Feb 17, 1978 |
| Grant date | Dec 11, 1979 |
| Priority date | — |
| Expiry date | Feb 17, 1998 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH04N9/72
- WIPO fieldAudio-visual technology
- WIPO sectorElectrical engineering
Abstract
A circuit utilizing a single clamp, and therefore requiring only a single bias supply, to DC clamp the inputs of the three chrominance amplifiers is shown. The clamp employs a switch that is connected to the bias supply and coupled by separate diodes to the inputs of the chrominance amplifiers. The switch and diodes are conductive only during the horizontal retrace period. As a result, during the retrace period, the amplifier inputs are clamped to a DC value determined by the bias supply; during the trace, or information-bearing period the inputs are isolated from the supply, as well as from each other.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.