Patent · US Expired

Electric discharge tube or discharge lamp and scandate dispenser cathode

US6348756B1 · kind B1 · utility

2Cited by

7References

8Claims

0Family size

Assignee

U.S. Philips Corporation · US

Inventors

Georg Gartner · Aachen, DE
Peter E. E. Geittner · Aachen, DE
Ernst Klein · Düsseldorf, DE

Key dates

Filing date	Jul 30, 1996
Grant date	Feb 19, 2002
Priority date	—
Expiry date	Nov 16, 2017

Classification

Technology area (CPC H)Electricity
CPC primaryH01J1/28
WIPO fieldElectrical machinery, apparatus, energy
WIPO sectorElectrical engineering

Abstract

An electric discharge tube or discharge lamp comprising a scandate dispenser cathode which is composed of a cathode body and a coating having an emissive surface, said cathode body including a matrix of at least one refractory metal and/or a refractory alloy and a barium compound which is in contact with the matrix material to supply barium to the emissive surface by means of a chemical reaction with said matrix material, and the coating containing one or more multilayers which may include a bottom layer of tungsten and/or a tungsten alloy, an intermediate layer of rhenium and/or a rhenium alloy and a top layer of scandium oxide, a mixture of scandium oxide and rare-earth metal oxides, a scandate and/or a scandium alloy, is characterized by a long service life and a high emission-current density.

Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.