Improvements relating to electron guns for cathode ray tubes

656,617. Cathode-ray tubes. ELECTRIC & MUSICAL INDUSTRIES, Ltd. July 13, 1948, No. 18763. [Class 39 (i)] An electron gun comprises a modulating electrode which consists of a film on an insulating surface facing the cathode. A metal sleeve 5 supports the tubular thermionic cathode 2 through the ceramic disc 4 and carries a lip 7 which, with the spacer ring 8, registers a ceramic or mica disc 6 on which is evaporated or sputtered the films 11, 12 forming respectively the modulating electrode and first anode; each film overlaps only its respective terminal contact 13, 14 moulded or inserted in the insulator. A retaining sleeve 9 and a second anode 15 are provided and the anode 12 may alternatively be independently supported by rods. Dimensions of the electrode 11 and insulator 6 are specified.