The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Feb. 03, 1976
Filed:
Jul. 18, 1974
Pieter Schagen, Salfords, near Redhill, EN;
Pamela May Stubberfield, Salfords, near Redhill, EN;
U.S. Philips Corporation, New York, NY (US);
Abstract
A flat large-area photocathode intended for use in an intensifier tube is constructed so that a pre-determined potential gradient can be maintained across its surface in operation in order to simplify the electron-optical system of the intensifier. This is done by providing photoemissive material on an electrically resistive layer or sheet on a major surface of which is provided a series of spaced rings of electrically conductive material one inside the other. The spacings and widths of the rings are chosen so that, when a potential difference is applied between the center and the edge of the sheet or layer, the desired potential gradient is set up across the surface of the photocathode. The intensifier tube may be an x-ray image intensifier.