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:
Jul. 03, 1984
Filed:
Apr. 27, 1982
Norman F Gioia, Lombard, IL (US);
Fred H Seher, Lombard, IL (US);
Zenith Radio Corporation, Glenview, IL (US);
Abstract
A television cathode ray picture tube has an in-line electron gun for generating three coplanar electron beams. The raster pattern projected by the center beam is diminished in vertical height so as to be non-coextensive with the superimposed raster patterns projected by the off-axis beams. The method according to the invention for providing raster coextensiveness comprises embracing each off-axis beam at the point of beam egress from the gun with a pair of inwardly converging but non-intersecting magnetic field enhancer means in symmetrical relationship and defining an opening therebetween. Each member of the enhancer means is oriented at a predetermined convergence angle with respect to the plane of the three beam paths, and located at a predetermined distance from the tube axis. The enhancer means, the predetermined convergence angle and distance, and the separation and length of the enhancer means are such that the enhancer means is effective to divert the flux of the vertical deflection field through the opening between each pair of enhancer means onto the center beam. The height of the raster pattern projected by the center beam is enhanced into coextensiveness with the patterns projected by the off-axis beams.