Patent ID: 6329746
Filing Date: 2001-12-11
Classification: H01J

Abstract:
A cathode ray tube including an electron gun comprising cathodes and a plurality of electrodes and generating three in-line electron beams and a phosphor screen for use with an electron beam deflection device,said cathode ray tube including pole pieces of magnetic material in a deflection magnetic field produced by said electron beam deflection device for establishing at least one non-uniform magnetic field on each side of a central path of each of said three in-line electron beams at zero deflection for correcting deflection defocusing corresponding to deflection of said three in-line electron beams, andsaid pole pieces being (i) disposed within 50 mm from an end of a magnetic core on a cathode side thereof of said electron beam deflection device toward said cathodes of said electron gun, (ii) supported by a cup-shaped electrode having at least one electron beam hole in a bottom thereof on a cathode side thereof, and (iii) spaced from said at least one electron beam hole toward said phosphor screen.