Abstract: Among a plurality of electrodes composing an electron gun, at least one electrode is separated into two along a plane substantially perpendicular to a central axis, the two being a first cylindrical electrode and a second cylindrical electrode. Between the two electrodes, a connecting member in an approximate cylindrical shape having a slit is interposed, which electrically connects the first and second cylindrical electrodes with each other. The first and second cylindrical electrodes are fixed to a support rod via the connecting member and support portions provided on a side of the connecting member. Since a modulation magnetic field from outside a cathode-ray tube passes through the slit, eddy current loss can be reduced, whereby a desired electron beam modulation effect can be achieved.

Abstract: An electron gun that can provide a desired electron beam modulation effect without preventing a modulation magnetic field from passing from an exterior of the vacuum portion is provided. A part of a tubular G3 electrode in an electron gun is formed into a coiled portion to allow the modulation magnetic field to pass through the clearances between parts of a wire composing the coiled portion.

Abstract: A electron gun has a plurality of arranged tubular electrodes for passing electron beams inside the tubular electrodes, and the tubular electrodes are fixed to support rods respectively by support members. At least one of the tubular electrodes is separated into two parts, and the separated two tubular electrode parts are connected electrically with each other by a coil member provided therebetween. The coil member is composed of a wire with its tip ends being located within the spaces formed by the support members. A desired electron beam modulation effect can be provided without interrupting transmission of a modulation magnetic field from the exterior, and also electric field emission of electrons from the tip ends of the coil member is suppressed.

Abstract: Among a plurality of electrodes composing an electron gun, at least one electrode is separated into two along a plane substantially perpendicular to a central axis, the two being a first cylindrical electrode and a second cylindrical electrode. Between the two electrodes, a connecting member in an approximate cylindrical shape having a slit is interposed, which electrically connects the first and second cylindrical electrodes with each other. The first and second cylindrical electrodes are fixed to a support rod via the connecting member and support portions provided on a side of the connecting member. Since a modulation magnetic field from outside a cathode-ray tube passes through the slit, eddy current loss can be reduced, whereby a desired electron beam modulation effect can be achieved.

Abstract: A electron gun has a plurality of arranged tubular electrodes for passing electron beams inside the tubular electrodes, and the tubular electrodes are fixed to support rods respectively by support members. At least one of the tubular electrodes is separated into two parts, and the separated two tubular electrode parts are connected electrically with each other by a coil member provided therebetween. The coil member is composed of a wire with its tip ends being located within the spaces formed by the support members. A desired electron beam modulation effect can be provided without interrupting transmission of a modulation magnetic field from the exterior, and also electric field emission of electrons from the tip ends of the coil member is suppressed.

Abstract: Method and apparatus for manufacturing an electron gun. A beam spot coefficient is obtained from an electrostatic lens magnification and a spherical aberration coefficient of a set resistance distribution. Then, a first process loop is executed to select another resistance distribution that provides an approximate minimum value of the beam spot coefficient. It is then determined whether the beam spot coefficient is an approximate minimum value. The first process loop is repeatedly executed until the beam spot coefficient is determined to be equal to the approximate minimum value. At this point, a second process loop is executed to confirm the minimum value of the beam spot coefficient using an aberration-independent function that is dependent upon the electrostatic lens magnification and is not dependent upon the spherical aberration coefficient.

Abstract: Method and apparatus for manufacturing an electron gun. A beam spot coefficient is obtained from an electrostatic lens magnification and a spherical aberration coefficient of a set resistance distribution. Then, a first process loop is executed to select another resistance distribution that provides an approximate minimum value of the beam spot coefficient. It is then determined whether the beam spot coefficient is an approximate minimum value. The first process loop is repeatedly executed until the beam spot coefficient is determined to be equal to the approximate minimum value. At this point, a second process loop is executed to confirm the minimum value of the beam spot coefficient using an aberration-independent function that is dependent upon the electrostatic lens magnification and is not dependent upon the spherical aberration coefficient.

Abstract: Method and apparatus for manufacturing an electron gun. A beam spot coefficient is obtained from an electrostatic lens magnification and a spherical aberration coefficient of a set resistance distribution. Then, a first process loop is executed to select another resistance distribution that provides an approximate minimum value of the beam spot coefficient. It is then determined whether the beam spot coefficient is an approximate minimum value. The first process loop is repeatedly executed until the beam spot coefficient is determined to be equal to the approximate minimum value. At this point, a second process loop is executed to confirm the minimum value of the beam spot coefficient using an aberration-independent function that is dependent upon the electrostatic lens magnification and is not dependent upon the spherical aberration coefficient.

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.