Electric circuit arrangements incorporating cathode ray tubes
US4287450A · kind A · utility
Inventors
Key dates
| Filing date | Nov 9, 1976 |
| Grant date | Sep 1, 1981 |
| Priority date | — |
| Expiry date | Nov 9, 1996 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH01J29/488
- WIPO fieldElectrical machinery, apparatus, energy
- WIPO sectorElectrical engineering
Abstract
An electron gun assembly of a cathode ray tube comprises in the order named, a cathode, an apertured modulator electrode, a first and a second apertured anode and a third cylindrical focussing anode. The modulator electrode and the first anode are supplied with such potentials as to form a crossover of electrons therebetween and the second anode is supplied with such a lower positive potential than at the adjacent first and third anodes that the electron stream emitted from the cathode is formed into a narrow beam of electrons and is allowed to enter the third anode at a small angle of beam spread and comes to a focus on the screen of the tube by the third anode to produce a spot of small cross-sectional area.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.