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US 4,924,137 AGranted
Cathode for electron tube
AssigneeMitsubishi Denki Kabushiki Kaisha
InventorsKeiji Watanabe, Keiji Fukuyama, Masako Ishida, Ryo Suzuki, Masato Saito
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Abstract
An oxide-coated cathode for an electron tube comprises a layer (2) of an electron-emissive substance. This layer (2) contains: an alkaline earth metal oxide as a principal component containing at least Ba; an oxide of Sc; and at least one heat-resisting oxide selected from the group consisting of oxides of Al, Si, Ta, V, Cr, Fe, Zr, Nb, Hf, Ta, Mo and W.
Claims9
An oxide-coated cathode for an electron tube, comprising:
- a base (1) containing Ni as a major element, said base having an external surface;
- a reducing agent contained in said base (1)
- a layer (2) of an electron-emissive substance formed on a part of said external surface and containing
- (a) an alkaline earth metal oxide as a principal component containing at least Ba,
- (b) a compound of Sc, and
- (c) at least one heat-resisting oxide selected from the group consisting of oxides of Al, Si, Ti, V, Cr, Fe, Zr, Nb, Hf, Ta, Mo and W;
- and
- a heater (3) for heating said layer (2) of the electron-emissive substance.
5 more elements
An oxide-coated cathode for an electron tube, comprising:
- a base (1) containing Ni as a major element, said base having an external surface;
- a reducing agent contained in said base (1);
- a first electron-emissive layer (2a) formed on a part of said external surface and containing
- (a) an alkaline earth metal oxide containing at least Ba, and
- (b) a compound of Sc;
- a second electron-emissive layer formed on said first electron-emissive layer and containing
- (c) an alkaline earth metal oxide as a principal component containing at least Ba, and
- (d) at least one heat-resisting oxide selected from the group consisting of oxides of Al, Si, Ta, V, Cr, Fe, Zr, Nb, Hf, Ta, Mo, and W;
- and
- a heater (3) for heating said first and second electron-emissive layers (2a), (2b).
7 more elements
Dependencies are inferred from the claim text.