| 摘要 |
In a single-gun, plural-beam cathode ray tube, for example, a color picture tube, in which the plurality of beams originate in spaced relation to each other and are directed toward the receiving screen along convergent paths so as to impinge on the screen after intersecting each other at a location in the tube between the beam producing means and the screen, individual prefocusing electron lenses are provided for the beams at positions between the beam producing means and the location where the beams intersect and are operative to partially focus the respective beams on the screen, and a main focusing electron lens common to all of the beams is provided to complete the focusing of the beams on the screen, such main focusing lens having an optical center and being positioned to dispose the optical center thereof substantially at the location where the beams intersect for diminishing the effects of certain optical aberrations.
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