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

Abstract

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.