Abstract: In an internal magnetic shield (28) that is substantially in a shape of a hollow truncated pyramid which is rectangular in a cross section, and has a small diameter opening on the side of an electron gun, the short edges (52 and 54) at the small diameter opening are formed in the shape of an inverted trapezoid that drops toward the panel, and the long edges (56 and 58) are formed in the shape of an obtuse-angled isosceles triangle that rises toward the electron gun.

Abstract: A cathode ray tube is provided, in which the flatness of a tension mask constituting a color-selection mechanism is maintained by a suitable stretching force, while with the tension mask, the influence of external magnetic fields, such as the terrestrial magnetism is suppressed, and the shifting of the electron beam is reduced. A tension mask made of a magnetostrictive material is used, the tension mask is stretched by a stretching force in a range maintaining the flatness of the tension mask, and the direction and strength of the stretching force are set such that vertical magnetic permeability of the tension mask increases, due to a magnetoelastic effect caused by the stretching force in the magnetostrictive material of the tension mask.

Abstract: A color cathode ray tube having a striped phosphor screen is provided, in which color displacements due to the tube axis (Z-axis) component of the terrestrial magnetism can be decreased at low cost. A positive temperature coefficient thermistor and a degaussing coil are connected in series to an AC power source (AC 100V) via a switch. A rectifier/smoothing circuit is provided in parallel to the positive temperature coefficient thermistor. When the switch is turned on, an ordinary degaussing process due to the AC attenuating magnetic field interlinked to the degaussing coil is performed, and the DC magnetic field in the Y-axis direction interlinked to the degaussing coil decreases the influence of the terrestrial magnetism in the tube axis direction (Z-axis direction).

Abstract: A color cathode-ray tube apparatus having: a glass bulb including a face panel, a funnel, and a neck; a deflection yoke attached to the funnel to surround thereof; and a color-selection electrode disposed inside the face panel. A pair of degaussing coils are wound around the upper and lower portions of the glass bulb, respectively. A loop coil, which is disposed around the glass bulb between the color-selection electrode and the deflection yoke, includes: a first portion including two extending portions of the loop coil positioned over and below the glass bulb respectively, each center of the extending portions being substantially in a plane perpendicular to a tube axial of the glass bulb; and a second portion including two bent portions that are formed by bending right and left sides of an original form of the loop coil toward the neck.

Abstract: In the structure of the present invention, there can be provided a cathode ray tube in which deviation in the trajectory of the electron beams by the leakage magnetic field from the mask frame (1) is decreased by using a polygonal mask frame (1) in which the relative magnetic permeability of longer side members (31) out of two side members adjacent to each other at the joint portion of the mask frame (1) is the same as or larger than the relative magnetic permeability of the other side members (21). Thus, the significance of the present invention in industrial terms is large.

Abstract: An inner magnetic shield is provided that reduces mislanding lengths due to electron beam distortion caused by external magnetic fields such as terrestrial magnetism, thereby reducing the occurrence of drifted or uneven color throughout an entire display screen. The inner magnetic shield is of a tube with a plurality of side surfaces, and is provided with at least one skirt (37) that extends to the vicinity of a spanning member (41) at a location where the inner magnetic shield is not in contact with a holding member (42). The skirt (37) is magnetically coupled with the spanning member (42).

Abstract: An internal magnetic shield includes a pair of opposing long side walls (1), a pair of opposing short side walls (2), and an opening (3) enclosed by these side walls in the center. The short side walls (2) are provided with notches (4) having a substantially home-plate shape. This configuration can reduce mislanding of an electron beam on the entire screen and easily balance the amount of mislanding due to geomagnetism in the tube-axis direction and in the horizontal direction perpendicular to the tube axis. As a result, a cathode ray tube capable of displaying images without displacement and unevenness of colors can be provided.

Abstract: A cathode ray tube including an internal magnetic shield in the shape of a hollow rectangular frustum including two long sides opposite to each other and two short sides opposite to each other, having an opening at its top and bottom attached to a mask and a frame. Each long side has a long side extension at a horizontal center located at the top of the internal magnetic shield where an electron beam enters the internal magnetic shield. The long side extensions enable the magnetic shield to reduce the deviation of an electron beam within the magnetic shield caused by an external magnetic field such as that caused by terrestrial magnetism.

Abstract: An inner magnetic shield is provided that reduces mislanding lengths due to electron beam distortion caused by external magnetic fields such as terrestrial magnetism, thereby reducing the occurrence of drifted or uneven color throughout an entire display screen. The inner magnetic shield is of a tube with a plurality of side surfaces, and is provided with at least one skirt (37) that extends to the vicinity of a spanning member (41) at a location where the inner magnetic shield is not in contact with a holding member (42). The skirt (37) is magnetically coupled with the spanning member (42).

Abstract: A color cathode-ray tube apparatus having: a glass bulb including a face panel, a funnel, and a neck; a deflection yoke attached to the funnel to surround thereof; and a color-selection electrode disposed inside the face panel. A pair of degaussing coils are wound around the upper and lower portions of the glass bulb, respectively. A loop coil, which is disposed around the glass bulb between the color-selection electrode and the deflection yoke, includes: a first portion including two extending portions of the loop coil positioned over and below the glass bulb respectively, each center of the extending portions being substantially in a plane perpendicular to a tube axial of the glass bulb; and a second portion including two bent portions that are formed by bending right and left sides of an original form of the loop coil toward the neck.

Abstract: A cathode ray tube is provided, in which the flatness of a tension mask constituting a color-selection mechanism is maintained by a suitable stretching force, while with the tension mask, the influence of external magnetic fields, such as the terrestrial magnetism is suppressed, and the shifting of the electron beam is reduced. A tension mask made of a magnetostrictive material is used, the tension mask is stretched by a stretching force in a range maintaining the flatness of the tension mask, and the direction and strength of the stretching force are set such that vertical magnetic permeability of the tension mask increases, due to a magnetoelastic effect caused by the stretching force in the magnetostrictive material of the tension mask.

Abstract: A color cathode ray tube having a striped phosphor screen is provided, in which color displacements due to the tube axis (Z-axis) component of the terrestrial magnetism can be decreased at low cost. A positive temperature coefficient thermistor and a degaussing coil are connected in series to an AC power source (AC 100V) via a switch. A rectifier/smoothing circuit is provided in parallel to the positive temperature coefficient thermistor. When the switch is turned on, an ordinary degaussing process due to the AC attenuating magnetic field interlinked to the degaussing coil is performed, and the DC magnetic field in the Y-axis direction interlinked to the degaussing coil decreases the influence of the terrestrial magnetism in the tube axis direction (Z-axis direction).

Abstract: The distribution of magnetic field of the terrestrialmagnetism is complicated. Thus, it is difficult to compensate the deviation of the arrival point of the electron beam onto the fluorescent material plane due to the influence of external magnetic field such as the terrestrialmagnetic field, when only an inner magnetic shield and a mask are installed in a flat type color CRT to avoid such influence, in certain regions on the earth, where such CRT is used. The first countermeasure of the influence is using of a stripe type color cathode ray tube, which has a large allowance to the deviation of the arrival point of the electron beam in the vertical direction. Next countermeasure is disposing of a filler made from non-magnetic material or hard magnetic material and/or a gap between the inner magnetic shield and the frame of the mask so as to flow out the magnetic flux, which come from the edge of inner magnetic shield and tend to flow into the inside space of the mask.

Abstract: In the structure of the present invention, there can be provided a cathode ray tube in which deviation in the trajectory of the electron beams by the leakage magnetic field from the mask frame (1) is decreased by using a polygonal mask frame (1) in which the relative magnetic permeability of longer side members (31) out of two side members adjacent to each other at the joint portion of the mask frame (1) is the same as or larger than the relative magnetic permeability of the other side members (21). Thus, the significance of the present invention in industrial terms is large.

Abstract: A cathode ray tube including an internal magnetic shield which is a pyramid including two long sides opposite to each other and two short sides opposite to each other, and has an opening at its top, a mask, and a frame. Each long side has an extension at a horizontal center of its end located at an entrance from which an electron beam enters the internal magnetic shield, and the extension is higher than the two short sides at the entrance.

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.