U.S. Philips Corporation

Peter C Van Loosdregt

Waltherus W Van Den Hoogenhof

Marcel Brouha

Hubertus Joseph Ronde

Luminescent rare earth metal phosphate defined by the formula

Luminescent rare earth metal phosphate, luminescent screen provided with

In a cathode-ray tube for displaying colored pictures comprising in an evacuated envelope means to generate a number of electron beams, a display screen comprising a number of regions luminescing in different colors, and color selection means comprising a large number of apertures which assign each electron beam to luminescent regions of one color, in which color selection means a magnetic quadrupole field is generated to form a magnetic quadrupole electron lens in each aperture, which luminescent regions have the shape of substantially parallel strips the longitudinal direction of which is substantially parallel to the defocusing direction of the quadrupole lens, characterized in that the apertures are elongate, substantially hexagonal and symmetrical relative to their longitudinal axes and are situated with their longitudinal axes in a number of parallel rows which extend substantially parallel to the strips and the apertures of two juxtaposed rows are shifted relative to each other, it is possible, in spite of the large transmission of the color selection means, to obtain a display screen having very uniform phosphor strips.

Cathode-ray tube

A method of manufacturing a focusing shadow mask for a color cathode ray tube is disclosed in which two conductive plates, forming the electrode structure, are secured together by insulating material so that they do not contact each other. Prior to assembly, at least one of the plates is provided with a pattern of substantially parallel ridges joined together by strips much thinner than the ridges. The material of the thin strips is removed after the plates are secured together, so that the remaining ridge portions form a set of conductors with the spaces therebetween being aligned with apertures on the other plate to form a plurality of openings for passage of electron beams.

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Eindhoven, Netherlands

Peter C Van Loosdregt