Backporch gating pulse generator subject to disabling during vertical sync interval
US4583121A · kind A · utility
Assignee
Inventor
Key dates
| Filing date | Dec 14, 1983 |
| Grant date | Apr 15, 1986 |
| Priority date | — |
| Expiry date | Dec 14, 2003 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH04N9/72
- WIPO fieldAudio-visual technology
- WIPO sectorElectrical engineering
Abstract
In a TV receiver, a line-rate gating pulse generator includes a source of line-rate timing pulses of "backporch" timing relative to the horizontal blanking intervals of received TV signals. Normally, the time constant of a capacitor charging circuit, enabled by the leading edge of each timing pulse, is determinative of a fixed, finite width for output gating pulses which are generated in response to the timing pulses. However, during the appearance of a field-rate pulse (e.g., vertical drive pulse), the charging circuit is altered such as to establish a zero width for the output gating pulses, resulting in a desired field-rate blanking of the line-rate gating pulse output.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.