Dispenser cathode and method of manufacture therefor
AssigneeCeradyne, Inc.
InventorLouis R. Falce
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Abstract
A four-piece, easily manufactured dispenser cathode capable of current densities up to and exceeding 10 Amperes per square centimeter is particularly adapted for CRT applications because of its surprisingly low cost. A refractory material reservoir contains a pellet of tungsten and barium calcium aluminate and is sealed by a pellet of porous tungsten or tungsten mixture. The reservoir/pellet assembly is contained in a support cylinder to which the porous tungsten pellet may be welded. The inventive process includes the steps to prepare the pellets and assemble the four elements of the cathode.
Claims5
A dispenser cathode for cathode ray tubes comprising:
- a reservoir formed of a refractory metal;
- a first pellet contained within said reservoir formed by a mixture of about 50% to 80% barium calcium aluminate and about 20% to 50% tungsten;
- a second pellet overlying and sealing said reservoir and comprising pressed and sintered porous tungsten;
- and
- means for applying heat to said reservoir and pellets for emitting current therefrom;
- said second pellet having no non-metal constituents which could otherwise clog pores in said second pellet.
Dependencies are inferred from the claim text.