GB440390A - Improvements in or relating to cathode ray apparatus - Google Patents

Abstract

440,390. Cathode-ray tubes. MARCONI'S WIRELESS TELEGRAPH CO., Ltd., Electra House, Victoria Embankment, London. (Assignees of Orth, R. T. ; 300, Carteret Place, Orange, New Jersey, U.S.A.) May 30, 1934, No. 33409 /35. Convention date, May 30, 1933. Divided out of 439,492. [Class 39 (i)] The intensity of the ray from the indirectly heated cathode 18, Fig. 2, and so the light at the fluorescent screen 4, is modulated by a conductor 14 which extends across, and divides into equal parts, a circular, square or other aperture 11, Fig. 3<a>, in a shield electrode 10 and which is at right angles to the direction of scanning lines on the screen 4. The conductor 14 is a stretched wire welded to the electrode 10. The negative potential of the electrode 10 is varied to modulate the ray and the wire 14 produces a variable cutoff diametrically across the ray without varying the boundary of the area of the screen 4 struck by the ray. The ray is focused by means of an apertured diaphragm 29, a first anode 19 with diaphragms as shown and a second anode formed by a coating on the conical part of the envelope of the tube. The ray is deflected to scan the screen 4 by electrostatic or magnetic devices or by a combination of non-magnetic, electrostatic devices with magnetic devices.