Dual-mode electron gun with improved shadow grid arrangement
US4553064A · kind A · utility
Assignee
Inventor
Key dates
| Filing date | Aug 30, 1983 |
| Grant date | Nov 12, 1985 |
| Priority date | — |
| Expiry date | Aug 30, 2003 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH01J23/065
- WIPO fieldElectrical machinery, apparatus, energy
- WIPO sectorElectrical engineering
Abstract
A dual-mode electron gun for a traveling-wave tube is disclosed which selectively generates an electron beam of two different cross-sectional areas. The electron gun includes radially inner and annular control grids as well as a shadow grid disposed between the cathode and the control grids along the electron beam path. The shadow grid is provided with a suppressor ring which precludes electron emission from an annular portion of the cathode immediately radially outwardly of the cathode region over which the inner control grid projects, thereby eliminating generation of a spurious beam portion radially outwardly from the desired smaller cross-section beam.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.