Abstract: An indirect cathode sleeve and manufacturing method thereof capable of substantially reducing electric power consumption of a heater disposed inside the cathode sleeve and simultaneously reducing a picture-producing time by oxidizing an inside surface of the cathode sleeve and reducing an outside surface thereof. The cathode sleeve includes a heater disposed inside the cathode sleeve; a base metal formed at the top of the cathode sleeve; an electron-emitting material layer formed at the outside surface of the base metal; and an indirect cathode sleeve including a black inside surface and a white outside surface.

Abstract: This invention relates to an indirectly-heated cathode heater structure comprising a heat generation section disposed inwardly of an upper portion of a sleeve for generating heat to emit thermions at an electron gun of a cathode ray tube, the heat generation section having a given calorific value being formed to have a length 25.about.33 % of the length of the sleeve, whereby heat loss at a lower portion of the sleeve during heating operation of the heater may be minimized, resulting in improving an overshoot rate of the heater.

Abstract: An improved cathode structure in an electron gun for a cathode ray tube comprises a sleeve having a cylindrical shape, a heater disposed in the interior of the sleeve, a cap disposed at the upper portion of the sleeve, and an electron-emitting material layer coated on the outer top surface of the cap. A gap having a dimension that is 13.5% to 15.5% of the inner diameter of the sleeve, is defined between the sleeve and the heater, thereby improving an overshoot in emission of electrons at an initial operation state of heater.