D.C.-coupled video clamping circuit
US4688097A · kind A · utility
16Cited by
4References
3Claims
0Family size
Assignee
Inventor
Key dates
| Filing date | Oct 30, 1986 |
| Grant date | Aug 18, 1987 |
| Priority date | — |
| Expiry date | Oct 30, 2006 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH04N7/1713
- WIPO fieldAudio-visual technology
- WIPO sectorElectrical engineering
Abstract
A d.c.-coupled video clamping circuit is disclosed for operation with normal video signals and sync suppressed scrambled video signals. For receiving normal video signals, a feedback path detects variations in sync tip level from a reference level and applies a corresponding control voltage to a d.c. signal amplifier, thereby to clamp and maintain the sync tip at a fixed (black) level. For receiving sync suppressed scrambled video signals, the feedback path is disabled and a fixed reference voltage is applied to the d.c. signal amplifier.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.