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:
Dec. 21, 1999
Filed:
May. 06, 1996
Masayoshi Misono, Chousei-gun, JP;
Hitachi, Ltd., Tokyo, JP;
Abstract
A cathode ray tube includes an electron gun having a plurality of electrodes, an electron beam deflection device and a phosphor screen. A method of correcting deflection defocusing in the cathode ray tube includes placement of pole pieces of magnetic material in a deflection magnetic field produced by the electron beam deflection device and thereby establishing a non-uniform magnetic field varying in synchronism with the deflection magnetic field in a path of an electron beam and correcting deflection defocusing of the electron beam corresponding to deflection of the electron beam in amount. The pole pieces are disposed within 50 mm from a magnetic core of the electron beam deflection device toward a cathode of the electron gun.