Cathode-ray tube having a focusing color-selection structure and a

Abstract

The novel CRT includes a color-selection structure which comprises a first electrode having a plurality of column and row elements forming a plurality of apertures, and a second electrode including an array of conductors electrically insulated from the first electrode. The plurality of apertures in the first electrode comprise alternate columns of first and second apertures. The first apertures have a width less than the width of the second apertures which are intersected by the conductors of the second electrodes to form first and second windows. The CRT also includes a viewing screen comprising an array of substantially parallel phosphor stripes of three different emission colors arranged in cyclic order in adjacent triads. Each of the triads of phosphor stripes is associated with a column of first and second windows and a column of first apertures. The column of first apertures is aligned with one of the phosphor stripes of the triad and is flanked on one side by a column of first windows and on the other side by a column of second windows. A method of producing an image screen using the novel color-selection structure is also disclosed. The method comprises the steps of: (a) providing the conductors of the second electrode of the color-selection structure with an opaque light blocking structure to temporarily close the first and second windows, (b) projecting light through the first apertures of the first electrode whereby to photodeposit the screen, and (c) then removing the opaque light blocking structure from the conductors of the second electrode to open the first and second windows.