Electrostatically focusing type image pickup tubes and method of manufacturing the same
AssigneeHitachi, Ltd.
InventorsShigeru Ehata, Hideyuki Sakai, Kinjir Gunbe
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Abstract
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.
Claims13
An electrostatically focusing type image pickup tube comprising an electron gun assembly made up of a cathode electrode, first and second grid electrodes and an apertured electrode for passing an electrode beam;
- an electron lens assembly made up of cylindrical third, fourth and fifth grid electrodes;
- a target including a transparent conductive film and a photoconductive film;
- a mesh electrode located between said electron lens assembly and said target;
- and a cylindrically envelope containing above described elements, wherein the inner diameter of said fourth grid electrode is smaller than that of said fifth grid electrode, and the inner diameter of said third grid electrode is smaller than that of said fourth grid electrode,
- means for impressing a first voltage upon said second and fifth grid electrodes, means for impressing a second voltage which is higher than said first voltage upon said third grid electrode and said mesh electrode and means for applying a third voltage which is lower than said first and second voltages upon said fourth grid electrode.
An electrostatically focusing type image pickup tube comprising an electrode gun assembly made up of a cathode electrode, first and second grid electrodes and an apertured electrode for passing an electron beam;
- an electron lens assembly made up of cylindrical third, fourth and fifth grid electrodes;
- a target including a face plate, transparent conductive film, and a photoconductive film which are formed on said face plate;
- a mesh electrode disposed between said electron lens assembly and said target;
- and a cylindrical envelope containing above-mentioned elements;
- the inner diameter of said fourth grid electrode being smaller thaw that of the fifth grid electrode, the inner diameter of said third grid electrode being smaller than that of said fourth grid electrode, said second and fifth grid electrodes being electrically interconnected in said envelope and said third grid electrode and said mesh electrode being electrically interconnected in said envelope,
- means for impressing a first voltage upon said second and fifth grid electrodes, means for impressing a second voltage which is higher than said first voltage upon said third grid electrode and said mesh electrode and means for applying a third voltage which is lower than said first and second voltages upon said fourth grid electrode.
Dependencies are inferred from the claim text.