Method and apparatus for controlling alignment of an electron beam of a variable shape
US4423305A · kind A · utility
14Cited by
4References
18Claims
0Family size
Assignee
Inventor
Key dates
| Filing date | Jul 30, 1981 |
| Grant date | Dec 27, 1983 |
| Priority date | — |
| Expiry date | Jul 30, 2001 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH01J37/304
- WIPO fieldElectrical machinery, apparatus, energy
- WIPO sectorElectrical engineering
Abstract
An electron beam, which is applied along an axis from a source to a target, is aligned along the axis by deflecting the beam off the axis to a reference location. At the reference location, the source image of the electron beam is centered on a sensing plate through shifting the beam by an alignment yoke until the sensed current is a maximum through correction signals that are supplied to the alignment yoke. These correction signals are continuously applied to the alignment yoke when the electron beam is returned from the reference location to the position in which it is applied to the target.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.