Cathode ray tube with an electron lens for deflection amplification

摘要

A generally box shaped, electronic lens system is incorporated in a cathode ray tube for amplification of both horizontal and vertical deflections of the electron beam. The lens system comprises two electrodes, one partly nested in the other with an insulating gap therebetween and both so disposed as to encompass the trajectories of the beam from the deflection system to the target of the CRT. A postaccelerating or other postdeflection electrode is provided to exert its field upon at least the target side end of the lens system. Upon application of prescribed potentials to the two lens electrodes and to the postdeflection electrode, the lens system provides a quadrupolar lens therein for deflection amplification in both directions. The lens system further coacts with the postdeflection electrode to create another electron lens adjacent its beam exit end for converging the beam in one of the orthogonal directions of beam deflection.