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:
May. 17, 1988
Filed:
Jun. 17, 1986
Leonard Dietch, Skokie, IL (US);
Zenith Electronics Corporation, Glenview, IL (US);
Abstract
A color cathode ray tube is disclosed having a front assembly with a shadow mask characterized by having circular apertures at the mask center, and apertures at least in the mask periphery increasingly elongated radially outwardly as a function of distance from the center. The elongation of the apertures is effective to reduce or eliminate the distortion of the deposits on the mask periphery produced by diffraction effects during photoscreening, and to form phosphor deposits compatible in size and shape with the electron beamlets. The screen of the tube according to the invention may have circular or near-circular phosphor deposits thereon. Tube types to which the invention can be applied include the conventional curved-screen/curved-mask tube, and the substantially flat faceplate tube that has a foil shadow mask suspended in tension a predetermined distance from the screening surface. A method is also disclosed for use in the photo-fabrication of a faceplate for an ultra-high resolution color cathode ray tube.