Hitachi, Ltd.

Hitachi Device Engineering Co., Ltd.

Hitachi Electronics Devices Co., Ltd.

Takashi Kinami

Shoji Shirai

Go Uchida

Noboru Mizukami

A color display system including color cathode ray tube has an evacuated envelope including a panel which carries a phosphor screen, a glass neck which houses an electron gun mount assembly, a funnel connecting the faceplate panel and the glass neck, and a stem having a plurality of leads therethrough sealed to and closing the neck at an end thereof; and an electron gun mount assembly. The electron gun mount assembly is supported on the stem via the plurality of leads and has a cathode for generating an electron beam and directing it toward the phosphor screen, a beam control grid electrode, an accelerating electrode, a plurality of focusing electrodes, one of which focusing electrodes is adapted to be supplied with a voltage varying in accordance with an amount of deflection of the electron beam, an anode electrode, and a heater for heating the cathode. One of two terminals of the heater and the beam control grid electrode is connected to a common one of the plurality of leads for being supplied with a variable voltage for beam control. The other one of the two terminals of the heater is adapted to be supplied with a sum of the variable voltage for beam control and a voltage for heating the cathode.

Color display system with color cathode ray tube having a high breakdown

A color cathode-ray tube has an in-line type electron gun. Third, fourth, and fifth electrodes form a sub-main lens, and a sixth electrode forms a main lens with the fifth electrode for focusing the three electron beams onto the phosphor screen. The second and fourth electrodes are electrically connected together and the third and fifth electrodes are electrically connected together. A ratio A of an axial length of the fourth G4 electrode to a diameter of the opening of the fourth electrode and a ratio B of an axial length of the fifth G5 electrode to the diameter of the opening of fourth electrode satisfy the following equations: 54A-5B+4.ltoreq.0, 55A-5B+7.gtoreq.0, A-0.18.gtoreq.0, and 95A+10B-73.gtoreq.0.

Color cathode-ray tube with reduced moire

An electron gun for a color cathode-ray tube has cathodes for producing electron beams and a control electrode unit, a focusing electrode unit and an accelerating unit successively arranged in a direction of the axis of the electron gun. One or more of the above-mentioned electrode units is made of an alloy containing 38-50 Wt % of Ni, 16-20 wt % of Cr and the balance of Fe. This alloy may have a thermal expansion coefficient not higher than about 15.times.10.sup.-6 /.degree.C. and or a relative permeability not higher than about 1.5.

Growing community of inventors

Mobara, Japan

Takashi Kinami