CATHODE RAY TUBE WITH DEVICE FOR PREVENTING MIS-LANDING OF ELECTRON BEAM BY EARTH MAGNETISM

摘要

PURPOSE: A cathode ray tube is provided to maintain superior color purity characteristics by minimizing influence of electron beam by east-west direction horizontal component force. CONSTITUTION: A cathode ray tube comprises a panel(20) having a screen part(20a) with a phosphor screen, and a side surface(20b) formed along the circumference of the screen part; a funnel(22) connected to the panel, and which has a deflection device(26) installed at the outer periphery of the funnel; a neck(24) connected to the funnel, and which has an electron gun(28) installed within the neck so as to generate electron beams to be radiated to the phosphor screen; a color discrimination unit(30) mounted inside the panel, and which color discriminates electron beams, and permits electron beams to reach the corresponding phosphor of the phosphor screen; and an inner shield(40) connected to the color discrimination unit and disposed toward the neck so as to shield an earth magnetism influencing on the track of electron beams. The color discrimination unit includes a mask(32) having a plurality of electron beam passing holes and a longer axis and a shorter axis; a frame(34) where the mask is fixed and supported, being stretched in the longer or shorter axis direction; and a side shield member(42) having a permeability higher than the permeability of the inner shield, and which is fixed to the shorter side of the frame so as to shield an earth magnetism including on the track of electron beams passed through the frame and mask.