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:
Apr. 12, 1988
Filed:
Jul. 20, 1987
Roger C Alig, West Windsor Township, Mercer County, NJ (US);
David A New, Manheim Township, Lancaster County, PA (US);
RCA Corporation, Princeton, NJ (US);
Abstract
The present invention provides an improvement in color picture tubes. Such tubes include an electron gun for generating and directing three inline electron beams, a center beam and two side beams, along initially coplanar paths toward a screen of the tube. The gun includes a plurality of spaced electrodes which form a main focus lens for focusing the electron beams. The improvement comprises the plurality of spaced electrodes which form a main focus lens including four electrodes that form an einzel lens in the path of each electron beam. A first einzel lens electrode includes a first portion having three inline apertures that are set back from a second portion having a single large aperture through which all three electron beams pass. A second einzel lens electrode includes a first portion having three inline apertures that are set back from a second portion having a single large aperture through which all three electron beams pass. The second portion of the first einzel lens electrode faces the second portion of the second einzel lens electrode. A third einzel lens electrode includes a first portion having three inline apertures that are set back from a second portion having a single large aperture through which all three electron beams pass. A fourth einzel lens electrode includes a first portion having three inline apertures set back from a second portion having a single large aperture through which all three electron beams pass. The second portion of the third einzel lens electrode faces the second portion of the fourth einzel lens electrode. The first portion of the second einzel lens electrode and the first portion of the third einzel lens electrode face each other and include means for forming a quadrupole lens in the path of each electron beam therebetween.