MAGNETIC ELECTRON LENS FOR CATHODE-RAY TUBE

摘要

An astigmatic cross-over of the electron beam produced by an electron gun in a cathode ray tube is effected by a non-circular symmetrical magnetic field produced by a permanent magnet arrangement provided in the vicinity of the grid of the gun. The spot produced by the beam on the display screen of the tube has a minimum of haze surrounding it and has dimensions which do not vary substantially with potential variations at the grid.