Abstract: There is disclosed a direct-heated cathode structure which comprises an insulating substrate; a pair of conductive supporting rods penetrating the substrate in the direction substantially perpendicular to the surface of the substrate and fixed tightly to the substrate; and a conductive member made of a single metal plate and including a first portion which is arranged in a plane spaced apart from the surface of the substrate by a predetermined distance and substantially parallel to the surface of the substrate and is coated with an electron emissive material, second portions which are extended from the first portion in the above-mentioned parallel plane substantially symmetrically with respect to the first portion, third portions which are extended from the end of extension of each of the second portions in the direction substantially perpendicular to the surface of the substrate toward the substrate, and fourth portions which are extended from the ends of the third portions in the direction substantially par

Abstract: A directly heated cathode for electron tube having a stable electron emission characteristic and a low cut-off voltage is provided. The cathode comprises a base metal of an alloy consisting essentially of 20-30% by weight of tungsten and a trace amount to 0.25% by weight of zirconium, the balance being nickel, binder dots of metallic nickel powders distributed on a flat part at the front side of the base metal, and a layer of thermoelectron emission oxides laid on the flat part at the front side of the base metal. The layer of thermoelectron emission oxides is in direct contact with the flat part through clearances among the binder dots of the metallic nickel powders.

Abstract: A silicon-semiconductor type thermal head comprising a substrate of .alpha.-alumina ceramic of single crystalline sapphire a silicon layer of high electrical resistance formed on the upper surface of the substrate and exothermic dots of low electrical resistance silicon integrally formed on the high resistance silicon layer.The silicon semiconductor type thermal head is formed by forming a substrate of .alpha.-alumina ceramic of single crystalline and sapphire, forming a high resistance layer of silicon on the .alpha.-alumina ceramic, forming a layer of low resistance silicon on the high resistance layer of silicon and selectively etching the low and high resistance silicon layers to produce exothermic dots of low resistance silicon, separated from the substrate by high resistance silicon.

Abstract: In a shadow mask assembly comprising a substantially rectangular shallow dish shaped shadow mask, a rectangular reinforcing frame having a side surface adapted to engage the periphery of the shadow mask and a transverse flat surface formed by a flange bent inwardly at right angles with respect to the side surface, and a plurality of leaf springs for supporting said shadow mask assembly, there are provided a plurality of depressions formed on the frame at points corresponding to the leaf springs.