Abstract: A cathode-ray tube, such as a camera tube or a display tube, having an electron gun with a cathode unit including a cathode shank (30) suspended coaxially in an aperture in an assembly plate (38) and extending perpendicularly to the longitudinal axis of the electron gun. The cathode unit includes a metal supporting plate (41) which is accurately positioned with respect to the assembly plate (38). The assembly plate (38) and the supporting plate (41) each have two apertures through which supporting pins (44) for electrical connection lugs (32) extend. Glass plugs (43) connect the assembly plate (38), the supporting pins (44) and the supporting plate (41) together.

Abstract: An electron gun for generating an electron beam, comprising a cathode unit composed of at least a cylindrical cathode shaft having an end surface which forms an emissive surface. The cathode shaft is surrounded at least partly by a cylindrical metal heat reflection screen which extends beyond the open end of the cathode shaft. The cathode shaft and the heat reflection screen are secured in a cathode support, wherein the cathode shaft is suspended in the heat reflection screen so as to be self-supporting by means of metal strips or wires which are secured to the cathode shaft near the emissive surface and to the cathode support. This arrangement increases thermal efficiency and decreases warm-up time.

Abstract: The surface of a metal from the group of molybdenum, nickel, iron, tungsten and copper, or an alloy comprising at least one metal from this group, is made thermally black (black for thermal radiation) and very resistant to high temperatures. This is achieved by coating the metal or alloy with a layer of aluminum which is from one to a few .mu.m thick. The metal or the alloy thus coated is then heated in a nonreactive atmosphere until the aluminum has reacted with the metal or a metal from the alloy. Finally, the coated metal or alloy is fired in wet hydrogen so that the aluminum is partially oxidized from the compound of the aluminum with the metal or the alloy. In this manner a thermally black surface which can withstand very high temperatures is obtained.

Abstract: By embedding the impregnated and sintered molding of a dispenser cathode in a holder of metal foil of 10 .mu.m to 100 .mu.m thick, such that any gap between the molding and the holder is less than 10 .mu.m a dispenser cathode can be obtained having a long life and/or quick heating properties.