Color cathode ray tube having an improved electron gun

A color cathode ray tube, comprising:

• at least an envelope constituted by a panel portion, a neck portion and a funnel portion connecting the panel portion and the neck portion;
• an electron gun contained in the neck portion, constituted by a cathode for forming a plurality of electron beams arranged in-line, and a focusing electrode and an anode constituting a main lens for focusing and accelerating said electron beams;
• a fluorescent screen formed on an inner surface of the panel portion;
• a deflecting device provided so as to surround a transition region between the funnel portion and the neck portion;
• and
• a speed-modulation coil for controlling a scanning speed of said electron beams;
• wherein said focusing electrode and said anode are arranged in order from said cathode side toward said fluorescent screen side in an axial direction of the tube;
• said focusing electrode includes at least a first division electrode and a second division electrode arranged with a gap in the axial direction of the tube;
• said second division electrode is opposed to said anode and has, in an opposed surface thereof, a single opening for passing said plurality of electron beams in common;
• a length of said first division electrode in the axial direction of the tube is longer than a length of said second division electrode in the axial direction of the tube;
• the length of said second division electrode in the axial direction of the tube is within a range of from about 1.0 to 1.6 times the diameter of said single opening in the surface of said second division electrode in a direction at right angles with the in-line direction;
• and
• said speed-modulation coil is installed so as to surround the neck portion of the envelope of said color cathode ray tube where at least said first division electrode and said second division electrode of said focusing electrode of said electron gun are disposed.