Improvements relating to mosaic screens such as are utilised in television transmission tubes

摘要

674,976. Cathode-ray tubes. ELECTRIC & MUSICAL INDUSTRIES, Ltd. July 25, 1950 [July 28, 1949], No. 19827/49. Class .39 (i). A mosaic screen, e.g. as used in television pick-up tubes and employing cathode potential stabilization, comprises a multiplicity of conductive elements on an insulating surface and a conductive medium on the areas of the surface between the elements which is of less conductance than the elements and is such that the charges on the medium can leak to the conductive elements in a time of the order of a few, e.g. three, frame periods, thereby eliminating the photographic effect. The conductive elements may be continually sensitized with caesium, and the conductive medium may be a continuous thin layer of antimony deposited either before or after the conductive elements are formed. Alternatively the conductive medium may be a layer of chromium or platinum deposited before the conductive elements are formed.