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:
Sep. 29, 1998
Filed:
May. 27, 1997
Kenichi Watanabe, Ohtaki, JP;
Syoji Shirai, Mobara, JP;
Shinichi Kato, Mobara, JP;
Akiyoshi Tobe, Mobara, JP;
Hitachi, Ltd., Tokyo, JP;
Abstract
A color cathode ray tube having an in-line type electron gun includes an electron beam generating means having a plurality of electrodes and including at least a cathode for producing electron beams, a first electrode and a second electrode, both constituting control electrodes and arranged in that order, and a heater for heating the cathode; a third electrode, a fourth electrode and a fifth electrode, together constituting a first-stage focusing lens for focusing the three electron beams onto the phosphor screen; and a fifth electrode and a sixth electrode, both forming a second stage focusing lens. Electrical connections are made between the second electrode and the fourth electrode and between the third electrode and the fifth electrode. The first electrode has an aperture 0.45 mm or smaller in diameter, and the relation between a ratio A of the second electrode length to the second electrode aperture diameter and a ratio B of the fourth electrode length to the fourth electrode aperture diameter is so set as to satisfy all four expressions: 40A+88B-57.ltoreq.0, 100A-260B-22.gtoreq.0, 100A+176B-112.gtoreq.0 and B-0.125.gtoreq.0.