Hitachi, Ltd.

Hitachi Devices Co., Ltd.

Other

Satoshi Moriwaki

Mitsuhiro Sugiyama

Akihito Sudo

A color cathode ray has an electron gun which includes three cathodes for emitting three in-line electron beams and a plurality of electrodes fixed in a predetermined axially spaced relationship on insulating supports. At least one of the plurality of electrodes is cup-shaped and has a correction electrode therein, and edges of the correction electrode are formed with recesses and sloped portions. A distance L from a mouth of each of the recesses of the correction electrode to an inner wall of the at least one of the plurality of electrodes satisfies the following relationship: L&prime;&lE;L&lE;15 &mgr;m, where L&prime; is a height of a burr caused in press-forming of the recesses.

Color cathode ray tube having improved main lens

A color cathode ray tube includes a phosphor screen, a shadow mask closely spaced from the phosphor screen and an electron gun. The electron gun includes three cathodes for emitting three in-line electron beams and a plurality of electrodes each having electron beam apertures for passing the electron beams, the electrodes are fixed in a predetermined axially spaced relationship on insulating supports, at least one of the electrodes is cup-shaped and has a correction plate electrode therein welded thereto, and edges of the correction plate electrode are formed with recesses and have sloped portions extending in a direction away from the recesses toward an inner wall of the electrode containing the correction plate electrode.

Color cathode ray tube having improved main lens electrodes

A color cathode ray tube includes a phosphor screen, a shadow mask closely spaced from the phosphor screen and electron gun. The electron gun has a plurality of electrodes including a plurality of cathodes for emitting a plurality of in-line electron beams, a control grid having a plurality of in-line apertures centered with the cathodes, an accelerating electrode, a cup-shaped focus electrode and a cup-shaped anode fixed on insulating supports. Each of the cup-shaped focus electrode and anode has at a first end face thereof opposing the other of the cup-shaped focus electrode and anode, a single opening surrounded by a rim formed by turning in the end face thereof toward an interior thereof. Each of said cup-shaped focus electrode and anode has a correction plate electrode therein, has a step on an inner wall thereof at a position set back from the first end face thereof to provide a first portion having an inside diameter larger on an open end side thereof opposite the first end face, than that of a second portion thereof on a side of the first end face. The correction plate electrode is pressed against the step and fixed to the cup-shaped electrode, or is fixed in the second portion of the smaller inside diameter.

Growing community of inventors

Ichihara, Japan

Satoshi Moriwaki