GB441693A - Improvements in or relating to cathode ray tubes and methods and apparatus for making the same - Google Patents

Abstract

441,693. Cathode-ray tubes. TELEFUNKEN GES. FUR DRAHTLOSE TELEGRAPHIE, 12, Hallesches Ufer, Berlin. July 20, 1934, No. 21342. Convention date, July 31, 1933. [Class 39 (i)] In manufacturing cathode - ray tubes suitable for television reception and having, between the deflecting means 11, Fig. 1, and the luminescent screen 13, spaced, coaxial, ring electrodes 14 .. 19 each of internal diameter large compared with the deflection of the ray in the plane of the electrode, metal is deposited on the internal wall 12 of the tube by vaporization in vacuo, for example, by heating silver by eddy currents, and the gaps between the electrodes 14 .. 19 are then produced by removing the deposited metal at these places. This may be done by rotating a spindle 20, Fig. 2, carrying a lever 21 and brush &c. 22 pressed against the wall by centrifugal force, a lever 23 and weight 24 avoiding bending of the spindle. The electrodes 14 .. 19 are operated at increasing voltages so that the ray is accelerated across spherical equipotential surfaces S without being bent. The Specification as open to inspection under Sect. 91 comprises also making the electrodes 14 .. 19 by vaporizing metal from one or more wires surrounded by masks to prevent the deposition of metal on the gaps. It is stated that the voltages on the electrodes may be chosen to form equipotential surfaces with centres below the plates 11 thus producing bending of the ray and enlargement of the picture, that the equipotential surfaces may alternatively be produced by a current-carrying resistance helix and that the arrangement is applicable also to sound-recording oscillographs, amplifiers, cathode-ray relays with transverse deflection and R÷ntgen-ray tubes. This subjectmatter does not appear in the Specification as accepted.