| 摘要 |
Colour cathode ray tube (1) device having an electron gun (6) of the in-line type for generating three electron beams (7, 8, 9), a display screen (10) and deflection means (11) for scanning the electron beams over the display screen, wherein the electron gun comprises a main lens part for focusing the electron beams on the display screen, said main lens part comprising main lens electrodes (26, 27) having apertures for passing of the electron beams, at least one of said main lens electrodes comprising two sub-electrodes (26a, 26b) adjacent to each other, each of the sub-electrodes having a central (311, 321) and two outer apertures (312, 322, 313, 323), whereby in operation between the adjacent sub-electrodes a quadrupole field is generated. For the central apertures of the sub-electrodes it holds: xQa </= xQb and for the two outer apertures of the sub-electrodes it holds: yQa </= yQb. The accuracy with which the sub-electrodes are positioned with respect to each other is thereby increased, as is the quality of the quadrupole field formed between the apertures.
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| 申请人 |
PHILIPS ELECTRONICS N.V.;PHILIPS NORDEN AB |
发明人 |
VAN DER POEL, WILLIBRORDUS, ADRIANUS, JOHANNES, AN;VAN DE HEIJDEN, ANTONIUS, WILHELMUS, FRANCISCUS |
