Cathode for electron tube
US5698937A · kind A · utility
5Cited by
8References
8Claims
0Family size
Assignee
Inventors
Key dates
| Filing date | Feb 23, 1995 |
| Grant date | Dec 16, 1997 |
| Priority date | — |
| Expiry date | Feb 23, 2015 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH01J1/142
- WIPO fieldElectrical machinery, apparatus, energy
- WIPO sectorElectrical engineering
Abstract
A cathode for an electron tube has a layer of electron-emissive substance containing alkaline earth metal carbonates having capillary crystals, to which 0.01-20.0 wt % of both a lanthanum (La) compound and a magnesium (Mg) compound or an La--Mg compound, based upon the weight of the alkaline earth metal carbonate, is added. The cathode enjoys full interchangeability with a conventional oxide cathode and a 15-20% longer lifetime.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.