Patent ID: 6294866
Filing Date: 2001-09-25
Classification: H01J

Abstract:
A color cathode ray tube comprising a phosphor screen, an electron beam generating section having a cathode structure, a beam control electrode and an accelerating electrode for generating and controlling three electron beams arranged horizontally, a focus electrode and an anode constituting a main lens therebetween for focusing said three electron beams on said phosphor screen,said focus electrode including at least a first focus sub-electrode and a second focus sub-electrode on the order named from said cathode structure,said first focus sub-electrode having a plurality of vertical parallel plate-like electrodes arranged to sandwich respective beam apertures in an end thereof facing said second focus sub-electrode in a direction of an arrangement of said three electron beams and electrically connected to said first focus sub-electrode,said second focus sub-electrode having a plurality of horizontal parallel plate-like electrodes arranged to sandwich beam apertures in an end thereof facing said first focus sub-electrode in a direction perpendicular to said arrangement of said three electron beams and electrically connected to said second focus sub-electrode,one of said first focus sub-electrode and said second focus sub-electrode being adapted to be supplied with a voltage varying in synchronism with deflection of said three electron beams,said plurality of vertical parallel plate-like electrodes extending into a space defined by said plurality of horizontal parallel plate-like electrodes, and a vertical spacing V between said plurality of horizontal parallel plate-like electrodes and a gap L between said plurality of horizontal parallel plate-like electrodes and a top edge of said plurality of vertical parallel plate-like electrodes and a gap L between said plurality of horizontal parallel plate-like electrodes and a bottom edge of said plurality of vertical parallel plate-like electrodes satisfying a following relationship:0.38.ltoreq.L/(V/2).ltoreq.0.58.