Other

Hitachi, Ltd.

Hitachi Device Engineering Co., Ltd.

Tsutomu Tojo

Masayoshi Misono

Hiroyuki Tamura

A color cathode ray tube having at least an electron gun, 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 the electron beams and a fluorescent screen. The focusing electrode includes at least a first division electrode and a second division electrode arranged with a gap for controlling a scanning speed of the electron beams in common. The second division electrode is opposed to the anode and has, in an opposed surface thereof, a single opening for passing the plurality of electron beams in common. A length of the first division electrode in the axial direction of the tube is longer than a length of the second division electrode in the axial direction of the tube.

Color cathode ray tube having an improved electron gun

A color cathode ray tube having at least an electron gun and a fluorescent screen. The electron gun forms a plurality of electron beams arranged in line and includes a focusing electrode and an anode having a gap and providing a main lens for focusing and accelerating the electron beams. The focusing electrode includes at least a first division electrode and a second division electrode having the same potential and arranged with a gap in the axial direction of the tube. The second division electrode is opposed to said anode and has, in the opposed surface thereof, a single opening for passing the plurality of electron beams in common. The second division electrode is opposed to the first division electrode and has, in the opposed surface thereof, individual electron beam passing openings for the respective electron beams. The length of the second division electrode in the axial direction of the tube is shorter than the length of the first division electrode in the axial direction of the tube and the diameter of the individual electron beam passing openings in the surface of the second division electrode opposed to the first division electrode is smaller than the diameter of the single opening in the surface of the second division electrode opposed to the anode in a direction at right angles with the in-line direction. The length of the second division electrode in the axial direction of the tube is not smaller than the diameter of the single opening in a direction at right angles with the in-line direction.

A color cathode ray tube has at least an electron gun, constituted by a cathode for forming a plurality of electron beams arranged in line and a plurality of electrodes, and a fluorescent screen, wherein the plurality of electrodes including an anode are arranged in the axial direction of the tube and have dissimilar potentials, and a main lens is constituted of the anode and another electrode neighboring the anode. The electrode neighboring the anode includes at least two division electrodes having the same potential and being arranged with a gap in the axial direction of the tube, and one of the division electrodes is opposed to the anode and has, in the opposed surface thereof, a single opening for passing the plurality of electron beams in common. The one division electrode opposed to the anode has a length in the axial direction of the tube that is from about 1.0 to about 1.6 times as great as the diameter of the single opening in a direction at right angles with the in-line direction. The speed is efficiently modulated, and favorable focusing characteristics are obtained on the whole fluorescent screen.

Growing community of inventors

Mobara, Japan

Tsutomu Tojo