Photoconductive pickup tube with unitized electrode structure having the photoconductive target electrode spaced from the tube faceplate

Claim 1

A photoconductive pickup tube formed of a glass envelope having a wall portion, a closed end faceplate portion of similar material and an opposed base closure portion providing a hermetic enclosure having a longitudinal axis wherein the internal tube construction is a stacked unit comprising: a multielectrode beam forming structure having an extending substantially tubular control electrode with a mesh electrode member supported relative to and parallel with the open frontal end of saId tubular control electrode, said multielectrode beam forming structure having an axis substantially coincidental with said longitudinal axis of said envelope; a substantially transparent planar target substrate having front and rear surfaces positioned within said glass envelope in a manner spaced from said faceplate and adjacent to said mesh electrode; a photoconductive target electrode disposed on the rear surface of said substrate facing said mesh electrode; a target connection for said photoconductive target electrode formed to extend longitudinally in an insulative manner within said envelope; target spacer means positioned between said mesh electrode and said target substrate; provisions for supporting said target substrate relative to said control electrode; terminal spacing means extending longitudinally beyond said substrate and peripherally contiguous thereto in a manner to provide substantially resilient spacing between said substrate and the interior surface of said envelope faceplate, and a plurality of electrical connective means including said target connection arranged to extend from said internal tube structure through the base portion of said envelope.