Electrostatically focusing type image pickup tubes and method of manufacturing the same

摘要

The electron lens of an electrostatically focusing type image pickup tube comprises three coaxially arranged cylindrical electrodes and the inner diameters thereof are decreased from the side of a target toward an electron gun. The electron lens is assembled by successively fitting the three electrodes over a mandrel, the outer diameter thereof varying stepwisely in accordance with the inner diameters of the three electrodes, and then interconnecting the three electrodes by axially extending insulating supporting rods.