Electron gun
US4146818A · kind A · utility
Assignee
Inventor
Key dates
| Filing date | Jun 13, 1977 |
| Grant date | Mar 27, 1979 |
| Priority date | — |
| Expiry date | Jun 13, 1997 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH01J29/488
- WIPO fieldElectrical machinery, apparatus, energy
- WIPO sectorElectrical engineering
Abstract
An electron gun comprising in succession in a vacuum envelope an electron source electrode or cathode, a control grid electrode, a first accelerating electrode or anode and a first and second focussing electrode. It further comprises connections for subjecting in operation each electrode to a polarizing voltage. The first focussing electrode is raised in operation to a polarizing voltage several tens of times higher than the polarizing voltage of the anode which precedes it and the second focussing electrode is raised in operation to a polarizing voltage several times higher than the polarizing voltage of the first focussing electrode which precedes it. The first focussing electrode and the anode form thus a prefocussing lens while the second focussing electrode and the first focussing electrode form a main lens.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.