CATHODE RAY TUBE

摘要

A cathode ray tube comprising an extra electrode with which the electron beam can be concentrated on a diaphragm aperture and simultaneously a small predeflection of the electron beam is obtained. The extra electrode is, for example, tubular and has oblique cut ends and is situated between two other electrodes. If the extra electrode has the same potential as the two other electrodes it is inoperative. If a suitable negative voltage pulse is supplied to the extra electrode the electron beam is slightly deflected and also concentrated on the diaphragm aperture.