Patent ID: 7030548
Filing Date: 2006-04-18
Classification: H01J

Abstract:
1. A cathode-ray tube apparatus comprising: an electron gun assembly including an electron beam generating section that generates an electron beam, a prefocus lens section that accelerates and prefocuses the electron beam generated from the electron beam generating section, a sub-lens section that further prefocuses the electron beam that is prefocused by the prefocus lens section, and a main lens section that accelerates and focuses the electron beam, which is prefocused by the sub-lens section, onto a phosphor screen; and a deflection yoke that generates deflection magnetic fields for deflecting the electron beam, which is emitted from the electron gun assembly, in a horizontal direction and a vertical direction, wherein the prefocus lens section is formed by at least a screen electrode and a first focus electrode to which a voltage with a first level is applied, and the prefocus lens section is formed in a substantially rotation-symmetric fashion with respect to a direction of travel of the electron beam, the sub-lens section is formed by at least the first focus electrode and a second focus electrode to which a voltage with a second level that is lower than the first level is applied, the main lens section is formed by at least the second focus electrode and an anode electrode to which a voltage with a third level that is higher than the first level is applied, and the electron gun assembly includes an asymmetric electron lens section that makes a horizontal dimension of the electron beam, which is prior to entering the main lens section, greater than a vertical dimension thereof.