Electron gun for cathode ray tube
US5164640A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Dec 18, 1991 |
| Grant date | Nov 17, 1992 |
| Priority date | — |
| Expiry date | Dec 18, 2011 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH01J2229/4841
- WIPO fieldElectrical machinery, apparatus, energy
- WIPO sectorElectrical engineering
Abstract
In an electron gun for cathode ray tubes in which the second of three focusing electrodes is divided into first, second, and third auxiliary electrodes, applying a first dynamic voltage synchronous with vertical and horizontal deflection signals to the first and third auxiliary electrodes, a second dynamic voltage synchronous with the deflection signals to the second auxiliary electrode, and a static focusing voltage higher than the maximum of the first and second dynamic voltages to the first and third focusing electrodes. The electron gun uses two dynamic focusing voltages in a low voltage driving method for low dynamic focusing voltages, thereby greatly reducing the possibility of an arc discharge between electrodes and compensating for astigmatism of the electron beam due to the non-uniform magnetic field of the deflection yoke. A sharp picture is achieved by improving the focusing of the electron beam.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.