Video source selector
US4521810A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | May 3, 1983 |
| Grant date | Jun 4, 1985 |
| Priority date | — |
| Expiry date | May 3, 2003 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH04N5/268
- WIPO fieldAudio-visual technology
- WIPO sectorElectrical engineering
Abstract
A switching arrangement for selecting one of a number of video signals. The circuit includes a switch unit preferably in integrated circuit form of pairs of synchronously operated switches for selecting video signal from a particular one of the video sources. A first switch of each pair is coupled to a respective video source for selectively providing a video signal to a common output when conductive. To provide sufficient isolation at video frequencies, the second switch of each switch pair is coupled between a reference potential and a respective one of a plurality of signal inhibiting stages for providing a control signal to the signal inhibiting stage dependent upon its conductive state. The inhibiting stages are coupled between the video sources and their respective first switches and are responsive to the control signals provided by respective ones of the second switches for selectively attenuating video signal from non-selected video sources and for passing the video signal from the selected video source.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.