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. 29, 1997
Filed:
Feb. 28, 1995
Mamoru Tsuzurahara, Mobara, JP;
Shoji Shirai, Mobara, JP;
Hitachi, Ltd., Tokyo, JP;
Abstract
A color cathode ray tube equipped with an electron gun having a main lens with a large equivalent aperture by suppressing spherical aberration and astigmatism of the main lens sufficiently. The main lens for converging the three electron beams, which are arranged generally in parallel in one direction toward the fluorescent face, upon the fluorescent face, includes two electrodes arranged to confront each other with such flattened apertures that the diameter H taken in the one direction is larger than a diameter V taken perpendicularly to the one direction. The orbits of the two side ones of the three electron beams passing through the main lens have a constant gap S from the orbit of the center electron beam. The relations of H=2(S+R) and R>S hold, if the distance between the orbits of the two side electron beams and the inner circumference, as taken in the one direction, of the electrodes constituting the main lens is designated at R.