Patent ID: 6570349
Filing Date: 2003-05-27
Classification: H01J

Abstract:
A cathode-ray tube apparatus comprising:an electron gun assembly having an electron beam generating section which generates at least one electron beam, and a main electron lens section which focuses the electron beam emitted from the electron beam generating section on a phosphor screen; and a deflection yoke which produces deflection magnetic fields for deflecting the electron beam emitted from the electron gun assembly and causing the electron beam to horizontally and vertically scan the phosphor screen, wherein the electron gun assembly comprises a plurality of electrodes including a cathode supplied with a voltage of a relatively low first level, which constitute the electron beam generating section, at least one focus electrode supplied with a focus voltage of a second level higher than the first level, at least one dynamic focus electrode supplied with a dynamic focus voltage obtained by superimposing an AC component varying in synchronism with the deflection magnetic fields upon a reference voltage of a level close to the second level, and at least one anode supplied with an anode voltage of a third level higher than the second level, a first dynamic focus electrode supplied with the dynamic focus voltage is disposed adjacent to the electron beam generating section, and a first focus electrode supplied with the focus voltage is disposed adjacent to the first dynamic focus electrode, when the electron beam is deflected, a first electron lens section created between the electron beam generating section and the first dynamic focus electrode has a focusing function in horizontal and vertical directions, and a first asymmetrical lens section created between the first dynamic focus electrode and the first focus electrode has a relative diverging function in the horizontal direction and a relative focusing function in the vertical direction, and the first electron lens section and the first asymmetrical lens section are electrostatically coupled.