Abstract: Out of focusing electrodes which face each other in an opposed manner and constitute an electrostatic quadruple lens, one focusing electrode includes planar correction electrode plates which extend parallel to a tube axis while sandwiching electron beams from above and below. Here, the correction electrode plates include a reinforcing mechanism for suppressing the deformation or the displacement of the planar correction electrode plates. By suppressing the deformation and the displacement of the planar correction electrode plates which form the electrostatic quadruple lens, it is possible to provide a color cathode ray tube capable of exhibiting excellent focusing characteristics over an entire screen.

Abstract: A color cathode ray tube has a three in-line beam electron gun. The electron gun includes a first group of focus electrodes supplied with a first fixed focus voltage and a second group of focus electrodes supplied with a second focus voltage comprised of a fixed voltage and a dynamic voltage synchronized with beam deflection. Plural axially spaced electrostatic quadrupole lenses are formed between facing ones of the first and second groups of focus electrodes. One of the plural electrostatic quadrupole lenses nearest to the cathodes is configured so as to produce a lens action weaker on two side electron beams than on the center electron beam.