Loading patent…
AssigneeHitachi, Ltd.
InventorsToshiyuki Aida, Shigehiko Yamamoto, Sadanori Taguchi, Isamu Yuito, Yukio Honda, Ushio Kawabe, Akira Misumi, Takao Kawamura, Hiroshi Fukushima, Yoshio Degawa
Estimating the term…
An electron tube cathode has a composite suppression layer structure interposed between the base metal and the electron-emitting material to suppress an interface layer formed through the reaction of the base metal with the electron emissive material. The composite layer structure includes a thin layer of Pt or Re and a layer of oxide of Zr and/or Hf. As a result, the formation of the interface layer is prevented so that the useful life of the electron tube cathode is prolonged.
An electron tube cathode comprising a base metal of Ni alloy containing W solved therein up to its solubility limit and a reducing impurity of small amount, a layer of an oxide of metal provided on said base metal including at least one material selected from a group consisting of Zr and Hf, a thin film of metal provided on said metal oxide layer including one selected from a group consisting of Pt and Re, and a coating of electron emissive material provided on said thin metal film including an alkaline earth metal oxide.
Dependencies are inferred from the claim text.