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

A cathode ray tube, comprising:

• an envelope having a fluorescent screen at one end and an electron gun at another end for producing an electron beam directed toward said screen;
• deflection means disposed along a tube axis of said envelope and including elements for deflecting said electron beam in mutually perpendicular directions;
• first quadrupole lens means disposed along said tube axis and positioned before said deflection means for focussing said electron beam in mutually perpendicular directions and second quadrupole lens means disposed along said tube axis and positioned between said elements of said deflection means for amplifying the electron beam deflection(s) while maintaining the electron beam velocity constant;
• and
• scan expansion post deflection acceleration means disposed along said tube axis between said deflection means and said screen for expanding the scan and simultaneously accelerating said electron beam for impinging onto said fluorescent screen to display an image thereon, said scan expansion post deflection acceleration means including tubular members, at least one of said tubular members having lobular sections positioned relative to each other to provide an accelerating quadrupole lens means.