Method of manufacturing a cathode ray tube for displaying colored pictures
AssigneeU.S. Philips Corporation
InventorsHubertus J. Ronde, Peter C. Van Loosdregt
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Abstract
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.
Claims18
In the manufacture of a colour cathode ray tube having an apertured shadow mask comprising an electrode structure for producing an electron field in the mask apertures, the method comprising the steps of securing a first electrically conductive plate having a plurality of parallel ridges joined together by relatively thin strips to a second electrically conductive plate having a plurality of apertures aligned with said strips by insulating material interposed between said plates to thereby form an electrode structure, removing at least portions of said strips to form in said first plate elongated apertures which are aligned with the apertures in said second plate to thereby form in said electrode structure openings for passage of electron beams, and mounting said electrode structure in an envelope of said tube.
In the manufacture of a colour cathode ray tube having an apertured shadow mask comprising an electrode structure for producing an electron focusing field in the mask apertures, the method comprising the steps of:
- producing a first metal plate comprising a plurality of relatively thick ridges joined together by relatively thin strips;
- covering said plate, except for said ridges which are kept uncovered, with insulating means;
- electrophoretically coating said ridges with glass powder;
- removing said insulating means, heating said plate and said glass powder to convert said powder into a solid;
- securing said first plate to a second apertured metal plate insulated from said first plate by said glass on said ridges with the apertures in said second plate being aligned with said strips to thereby form said electrode structure;
- removing at least portions of said strips to form in said first plate elongated apertures which are aligned with the apertures in said second plate to thereby form in said electrode structure openings for passage of electron beams, and mounting said electrode structure in an envelope of said tube.
In the manufacture of a colour cathode ray tube having an apertured shadow mask comprising an electrode structure for producing an electron focusing field in the mask apertures, the method comprising the steps of positioning a first electrically conductive plate having a plurality of parallel ridges joined together by relatively thin strips in substantially parallel, face to face relationship with a second electrically conductive plate having a plurality of apertures aligned with said strips, interposing an insulating material between said plates, adhering said plates to said insulating material to form said electrode structure comprising said plates spaced a predetermined distance from each other by said insulating material therebetween, removing at least portions of said strips to form, in said first plate, elongated apertures which are aligned with said apertures in said second plate to thereby form, in said electrode structure, openings for passage of electron beams, and mounting said electrode structure in an envelope of said tube.
Dependencies are inferred from the claim text.