Global Patent Index - EP 0330543 B1

EP 0330543 B1 19920122 - DIRECTLY HEATED CATHODE MANUFACTURED FROM THERMALLY EMISSIVE MATERIAL

Title (en)

DIRECTLY HEATED CATHODE MANUFACTURED FROM THERMALLY EMISSIVE MATERIAL

Publication

EP 0330543 B1 19920122 (FR)

Application

EP 89400375 A 19890209

Priority

FR 8802364 A 19880226

Abstract (en)

[origin: EP0330543A1] The present invention relates to a directly heated thermoelectron emission cathode. It consists of a hollow perforated cylindrical base structure made of pyrolytic graphite which is covered with a layer of the thermoemissive material. The loss of thermoemissive material by evaporation is limited by depositing a layer of a refractory material onto it. The refractory material is a compound of boron and a transition metal, or a compound of boron and a metal of the platinum type, or a compound of silicon and a metal, or a metal carbide. Application to cathodes for high power electron tubes or for electron microscope filaments.

IPC 1-7

H01J 1/15

IPC 8 full level

H01J 1/14 (2006.01); H01J 1/15 (2006.01)

CPC (source: EP)

H01J 1/15 (2013.01)

Designated contracting state (EPC)

DE FR GB NL

DOCDB simple family (publication)

EP 0330543 A1 19890830; EP 0330543 B1 19920122; DE 68900732 D1 19920305; FR 2627897 A1 19890901; FR 2627897 B1 19900622; JP H01292726 A 19891127

DOCDB simple family (application)

EP 89400375 A 19890209; DE 68900732 T 19890209; FR 8802364 A 19880226; JP 4042189 A 19890222