Abstract: In a cathode ray tube including a panel provided with a phosphor screen, a funnel integrated with the panel, an electron gun disposed inside the funnel, a magnetic shield (1) for shielding an electron beam (5) emitted from the electron gun against an external magnetic field, and a frame (2) for holding the magnetic shield (1), the magnetic shield (1) includes, at a portion to be joined with the frame (2), a bent portion (20) bent toward a tube axis side, and a thickness T of the bent portion (20) at its edge on the tube axis side is 0.08 mm or less. By making the thickness T small, halation that is liable to occur in a cathode ray tube with a large deflection angle can be suppressed because electron beams reflected from an end face (11) and allowed to reach the screen without being shielded by the frame (2) are reduced.

Abstract: In a cathode ray tube including a panel provided with a phosphor screen, a funnel integrated with the panel, an electron gun disposed inside the funnel, a magnetic shield (1) for shielding an electron beam (5) emitted from the electron gun against an external magnetic field, and a frame (2) for holding the magnetic shield (1), the magnetic shield (1) includes, at a portion to be joined with the frame (2), a bent portion (20) bent toward a tube axis side, and a thickness T of the bent portion (20) at its edge on the tube axis side is 0.08 mm or less. By making the thickness T small, halation that is liable to occur in a cathode ray tube with a large deflection angle can be suppressed because electron beams reflected from an end face (11) and allowed to reach the screen without being shielded by the frame (2) are reduced.

Abstract: In a cathode-ray tube, a nonmetallic material such as ceramic or the like is used for an electrode 1a part of an electron gun. Consequently, the deterioration of the efficiency of modulation of electron beam trajectories by an eddy current generated at the metallic electrode part of the electron gun in the high-frequency magnetic fields and the heat generation at the electrode can be decreased. The generation of the eddy current by high-frequency magnetic fields by a convergence yoke or the like can be restrained by using a nonmetallic material for the electrode part of the electron gun. Consequently, the efficiency of modulation of electron beam trajectories is not deteriorated also in a high-frequency modulation zone and the heat generation at the electrode part can be also restrained. Less deterioration of efficiency of modulation of electron beam trajectories by the alternating magnetic fields occurs even in the high-frequency modulation zone, for example, more than 100kHz.

Abstract: In order to provide a method of producing a cathode ray tube in a manner which well matches with a usual technique of producing a cathode ray tube by forming a spiral high-resistor on an inner face of a glass tube, in an electron gun of which a main focusing lens is configured by the spiral high-resistor, the step of fritting seal rings to both ends of the glass tube in which a hole is opened in the center portion; the step of applying a high-resistor paste to the glass tube, drying the paste, and then forming a spiral structure in the high-resistor film; the step of firing at 420 to 550 deg. C.; and the step of combining other electron gun parts to form the electron gun are included, and the spiral high-resistor is formed by a high-resistor paste in which ruthenium oxide is added to a glass material having a softening point that is lower than the annealing point of the glass tube.