Electron gun with low spherical aberration
US4649318A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Sep 23, 1985 |
| Grant date | Mar 10, 1987 |
| Priority date | — |
| Expiry date | Sep 23, 2005 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH01J29/488
- WIPO fieldElectrical machinery, apparatus, energy
- WIPO sectorElectrical engineering
Abstract
An electron gun of uni-potential type is disclosed, which includes a main electron lens system consisting of a front electron lens system formed of a third grid and a fourth grid and a rear electron lens system formed of the fourth grid and a fifth grid of which the electron lens action regions are separated from each other. In this case, the electron lens diameter of the front electron lens system is selected smaller than that of the rear electron lens system, and the aperture diameter of the fifth grid in the rear electron lens system is selected larger than that of the fourth grid, and may be nearly as large as the inner diameter of the tube in which it is placed for use.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.