(under subclass 461) Subject matter wherein the screen is of a material which incandesces when heated by the bombardment of electrons.
SEE OR SEARCH THIS CLASS, SUBCLASS:
305, and the subclasses specified in the notes thereto for other discharge devices under the class definition having anodes adapted to be heated by the discharge.
347, and the subclasses specified in the notes thereto for electrodes, per se, which are designed to be incandescible upon electron bombardment.
