CATHODE RAY TUBE

摘要

PROBLEM TO BE SOLVED: To make it possible to control the generation of an excess current and to display an image of high pixel density by realizing an enough velocity modulation. SOLUTION: A cartridge focusing electrode 4 that constitutes an electron gun is divided into the first cartridge focusing electrode 4B and the second cartridge focusing electrode 4T. A space between both electrodes formed by the division expands substantially by making it the most suitable in the tube axis direction of the second cartridge focusing electrode 4T and increases the invasion into non-electrode area of the focusing electrode of velocity modulation magnetic field. Constituting electrode 4a the same electrode as focusing electrode in the area controls the generation of the excess current.