Method and apparatus of automatically processing and correcting the blocking voltage of an electron gun
US4319166A · kind A · utility
4Cited by
2References
6Claims
0Family size
Assignee
Inventor
Key dates
| Filing date | Jul 9, 1980 |
| Grant date | Mar 9, 1982 |
| Priority date | — |
| Expiry date | Jul 9, 2000 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH04N9/72
- WIPO fieldAudio-visual technology
- WIPO sectorElectrical engineering
Abstract
The blocking voltage of an electron gun is corrected by periodically removing an input video signal and driving a cathode with a DC stabilizing voltage. A pulse perturbation is impressed upon a control grid and the cathode momentarily conducts more heavily to exceed a predetermined threshold corresponding to the limit of a black CRT picture. A feedback loop detects a response signal from the perturbation of cathode current and stores the response signal in a memory, the latter determining the corrected blocking voltage during normal operation of the gun.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.