Electron beam deflection lens for CRT

For use in a CRT for directing a focused electron beam onto a display screen of said CRT, wherein said CRT includes a glass envelope and a magnetic deflection yoke disposed about said glass envelope and forming a beam deflection region for displacing said electron beam across said display screen in a raster-like manner, an electron gun comprising:

• a source of energetic electrons;
• a first plurality of co-axially aligned, metallic electrodes maintained at a relatively low voltage and disposed adjacent said source of energetic electrons for forming said energetic electrons into a beam and directing said beam along an axis toward the display screen;
• and
• a second plurality of electrodes disposed on said axis intermediate said first plurality of metallic electrodes and the display screen and within the magnetic deflection yoke, wherein said second plurality of electrodes are maintained at a relatively high voltage and form a main focus lens with a beam focus region for focusing the electron beam on the display screen, wherein said beam deflection and beam focus regions are coincident along said axis and the electron beam is simultaneously magnetically deflected and electrostatically focused, and wherein at least one of said second plurality of electrodes is disposed on or in close proximity to an inner surface of a frusto-conical portion of the CRT's glass envelope.

For use in an electron gun in a CRT having a glass envelope with neck and frusto-conical funnel portions and a display screen, wherein said electron gun directs an electron beam onto said display screen and wherein said CRT includes a magnetic deflection yoke disposed about said glass envelope and forming a beam deflection region in said CRT for displacing said electron beam across said display screen in a raster-like manner, a deflection lens comprising:

• a first charged electrode located intermediate the magnetic deflection yoke and the display screen and disposed on or immediately adjacent to an inner surface of the frusto-conical funnel portion of the glass envelope;
• and
• a second charged electrode located adjacent to the magnetic deflection yoke and forming in combination with said first charged electrode a beam electrostatic focus region within the beam deflection region for the simultaneous focusing of the electron beam on the display screen and deflection of the electron beam across the display screen, wherein said deflection leans is characterized as having a focal point disposed on an axis of the electron beam and the magnetic deflection region is characterized as having an electron beam deflection center, and wherein said electron beam deflection center is disposed within the focal point of said deflection lens to provide increased electron beam deflection sensitivity.