Patent ID: 6621202
Filing Date: 2003-09-16
Classification: H01J

Abstract:
A cathode ray tube apparatus comprising:an electron gun assembly including an electron beam generating section for generating at least one electron beam, and a main focus lens section for focusing the electron beam on a screen; and a deflection yoke for generating deflection magnetic fields for deflecting and scanning the electron beam from the electron gun assembly on the screen in horizontal and vertical directions, wherein the main focus lens section comprises at least one focus electrode, to which a fixed focus voltage of a first level is applied, at least one anode to which an anode voltage of a second level higher than the first level is applied, at least one first auxiliary electrode to which a voltage obtained by resistor-dividing the anode voltage via a resistor and having a third level higher than the first level and lower than the second level is applied, and at least one dynamic focus electrode to which a dynamic focus voltage obtained by superimposing on a focus voltage an AC voltage varying in synchronism with the deflection magnetic fields generated by the deflection yoke is applied, the main focus lens section includes an ultimate main focus lens section composed of the dynamic focus electrode, said at least one first auxiliary electrode and the anode, which are arranged successively in a direction of travel of said electron beam, and at least one second auxiliary electrode connected to the first auxiliary electrode is provided on the electron beam generating section side of the ultimate main focus lens section, and an electrode to which a fixed voltage is applied is disposed near the second auxiliary electrode.