X-ray tube apparatus
US4730353A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Mar 30, 1987 |
| Grant date | Mar 8, 1988 |
| Priority date | — |
| Expiry date | Mar 30, 2007 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH01J35/30
- WIPO fieldElectrical machinery, apparatus, energy
- WIPO sectorElectrical engineering
Abstract
An X-ray tube apparatus comprises an X-ray tube which includes a vacuum envelope and an anode target and a cathode assembly which are disposed within the vacuum envelope opposing each other. The cathode block has a flat-plate like filament for generating an electron beam, and a beam shaping electrode insulated from this filament. The beam shaping electrode is formed with a beam limiting aperture for passing therethrough of a part of the electron beam emitted from the filament, and a focussing dimple so as to focus the electron beam. When d2 and d3 are assumed to represent the depth of the focussing dimple and the distance between the target surface and the top surface of the focussing dimple opposing this target surface, respectively, the value of the ratio of d3 to d2 satisfies the inequality 1.0.ltoreq.d3/d2.ltoreq.4.0.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.