Hot cathode in wire form
US4897574A · kind A · utility
4Cited by
1References
11Claims
0Family size
Assignee
Inventors
Key dates
| Filing date | Oct 5, 1987 |
| Grant date | Jan 30, 1990 |
| Priority date | — |
| Expiry date | Oct 5, 2007 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH01J61/0677
- WIPO fieldElectrical machinery, apparatus, energy
- WIPO sectorElectrical engineering
Abstract
A hot cathode in a wire form is useful in a vacuum tube, a CRT or a fluorescent display tube is disclosed. The cathode is composed of a heat-resistant metal in a wire form that holds on it an electron-emitting metal material that is made of 0.2-20 wt % of a rear earth metal oxide in admixture with an alkaline earth metal oxide the balance of which contains at least barium oxide. The reduction of oxide barium to barium as a result of reaction with the cathode wire is so much retarded that an increased emission current will be produced from the cathode not only in its initial operation but also through out its operation.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.