Cathode ray tube having an electron lens system including a meshless scan expansion post deflection acceleration lens

摘要

A cathode ray tube includes first and second electrostatic quadrupole lens between the electron gun and the vertical deflection plates to properly focus the electron beam before it enters the vertical deflection plates. A third electrostatic quadrupole lens is located between the vertical deflection plates and the horizontal deflection plates to enhance the angle of deflection as well as to properly focus the electron beam as it moves from the vertical deflection plates into the horizontal deflection plates. A meshless scan expansion lens follows the horizontal deflection plates and is formed of aligned tubular members having interdigitated sections thereby forming a fourth quadrupole lens which accelerates the electron beam and expands it prior to being impinged onto the fluorescent screen.