Abstract: In a color cathode ray tube comprising a panel with a substantially rectangular effective portion whose outside face is almost flat or slightly curved and whose inside face has a curvature in the direction of minor axis near the short sides of the portion, and a fluorescent substance screen having a substantially rectangular effective region formed on the inside face of the effective portion of the panel, the short sides in the outer circumference of the effective region of the fluorescent substance screen are projected toward the center of the effective region. This improves the flatness of images appearing on the fluorescent substance screen provided on the inside face of the effective portion in the color cathode ray tube with the outside face of the effective portion of the substantially rectangular panel being almost flat and the inside face having a curvature in the direction of minor axis at least near the short sides.

Abstract: A shadow mask opposing a phosphor screen includes a substantially rectangular mask body having a number of electron beam passage apertures, and a substantially rectangular mask frame having four side walls supporting a periphery of the mask body. Among the side walls, a pair of long side walls each has a central connecting portion which is located at a central portion thereof in lengthwise direction and fixed to the mask body, and a pair of protruding portions which are provided on both sides of the central connecting portion in the lengthwise direction and protrude in a direction apart from the mask body. Each protruding portion defines a gap between the side wall and the mask body, and a width of the gap gradually increases as it goes far from the central connecting portion.

Abstract: A color cathode ray tube comprises a panel having an effective portion. The outer surface in the effective portion of the panel is substantially flat or forms a slightly curved plane with a small curvature. The inner surface of the panel has a substantially infinite curvature radius in a direction of the longer axis in at least a central portion of the panel and is curved in a direction of the shorter axis. A difference in thickness of the effective portion of the panel between the central portion and the edge portions diagonally apart from each other exceeds 8 mm and does not exceed 20 mm, and the transmittance of the glass in the central portion of the effective portion is at least 70%. The particular construction enables the vacuum envelope of the color cathode ray tube to exhibit a mechanical strength high enough to sufficiently withstand the atmospheric pressure, though the effective portion of the panel is flattened.

Abstract: A face panel (12) constituting a part of a vacuum envelope (20) has a substantially rectangular effective area (10), the inner surface of which is formed with a phosphor screen (14). The effective area has a long axis (X) extending in the horizontal direction and a short axis (Y) extending in the vertical direction. The outer surface of the effective area is cylindrically curved with an infinitely large radius of curvature along the long axis and a predetermined radius of curvature along the short axis. The vacuum envelope has arranged therein a shadow mask (15) in opposed relation to the phosphor screen. A mask body of the shadow mask has a substantially rectangular effective surface cylindrically curved with an infinitely large radius of curvature along the long axis and a predetermined radius of curvature along the short axis thereof.

Abstract: In a method of testing a color cathode ray tube, an electron gun assembly is energized to emit electron beams and only a horizontal deflection magnetic field is applied to the electron beams so that a line image is displayed on a screen. A degaussing coil is located in front of the panel and a degaussing magnetic field having a frequency the same as that of a commercial power source. Thereafter, the degaussing coil is moved in a direction away from the panel and is deenergized when the coil is removed from the panel at a predetermined distance. A vertical deflecting coil is energized to display an image and a picture quality of the tube is tested.

Abstract: A color cathode ray tube has a substantially rectangular shadow mask in which a plurality of slit type aperture arrays are aligned in the direction of the major axis of an effective region defined by a curved surface opposing a phosphor screen formed on the inner surface, defined by a concave curved surface, of the effective region of a panel. Each slit type aperture array is obtained by arranging a plurality of slit type apertures in an array in the direction of the minor axis of the effective region of the shadow mask. In this color cathode ray tube, the difference between the array interval of the slit type aperture arrays at a peripheral portion on the long side of the shadow mask and the array interval of the slit type aperture arrays on the major axis is a maximum value within a distance range of 0.4 h to 0.

Abstract: A color-cathode ray tube having a shadow mask with improved aperture arrays. The aperture arrays are spaced at appropriate intervals and are curved to suppress local doming of the effective part of the shadow mask and to prevent electron-beam mislanding from occurring on a phosphor screen. The distance between any two adjacent apertures is expressed as: PH(N)=A+BN.sup.2 +CN.sup.4, where PH(N) is the distance between the (N-1)th and Nth arrays and A, B, and C are fourth-degree functions of a Y-coordinate. The apertures along a long side of the effective part of the shadow mask in a section extending for one-fourth of a width of the effective part of the shadow mask from a short side of the effective part of the shadow mask are inclined in an opposite direction to the apertures within the section and located one-third of a height of the effective part of the shadow mask from the long side.

Abstract: When an outer surface of an effective portion 20 of a panel 20 is substantially spherical, a diagonal axis of the effective portion, a long axial effective diameter, land a short axial effective diameter are Sd, Sh, and Sv, the panel is shaped to satisfy the relationship, Dp/Sd<0.05, V<H<D, 2V<Dp<2H where Dp an amount of drop at an end of the effective diameter of the diagonal axis, H an amount of drop at the end of the effective diameter of the long axis, V an amount of drop at the end of the effective diameter of the short axis, the relationship, Ah/Sh<A/Sv where Ah a distance in the long axial direction of a thicker region on the long axis and Av a distance in the short axial direction of the thicker region on the short axis, wherein, in the thicker region, the panel has a thickness larger than the average thickness Ta of the effective portion, and the relationship between a maximum thickness T max and a minimum T min, (Tmax-Ta)>(Ta-Tmin) or .vertline.T max-Ta.vertline.>.vertline.

Abstract: A shadow mask of a color cathode-ray tube includes a mask body in the form of a substantially rectangular curved surface. The mask body has a center, horizontal and vertical axes perpendicularly crossing each other at the center, long sides extending in parallel to the horizontal axis, and short sides extending in parallel to the vertical axis. In a region of the mask body which is adjacent to the vertical axis, the radius of curvature in the vertical direction is smaller at portions of the mask body which are near the long sides than at the central portion of the mask body. In a intermediate region of the mask body between the vertical axis and each short side, the radius of curvature in the vertical direction is larger at the portions of the mask body which are near the long sides than at a portion adjacent to the horizontal axis.

Abstract: A deflection device for use in a color cathode-ray tube, which has a pair of horizontal deflection coils for generating a pincushion-shaped horizontal deflection magnetic field, a pair of vertical deflection coils for generating a barrel-shaped vertical deflection magnetic field. The deflection device also having a pair of correction coils each of which being located at a distance of 10 mm or less from a plane containing the center and vertical axes of the device, a current flowing through each correction coil in synchronism with, and in a direction opposite to, the currents flowing in the horizontal deflection coils. The deflection device may also include a second pair of correcting coils, each of which being located adjacent to the first pair of correcting coils and arranged in a similar arrangement relative to the plane defined by the center and vertical axes.

Abstract: A color cathode ray tube includes a face plate having a curved inner surface and a substantially rectangular effective area. A phosphor screen is formed on the inner surface of the face plate, and a shadow mask is arranged to oppose the phosphor screen.

Abstract: A color cathode-ray tube includes a curved shadow mask formed having a number of apertures and a substantially rectangular effective surface facing the inner surface of the panel. The effective surface of the shadow mask has a center through which the tube axis passes, a horizontal axis passing through the center and at right angles to the tube axis, and a vertical axis extending and at right angles to the tube axis and the horizontal axis. The effective surface of the shadow mask is formed so that, in the region located on the horizontal axis, the radius of curvature in the direction of the horizontal axis of the surface is larger than the radius of curvature in the direction of the vertical axis of the surface in a region substantially halfway between the center of the surface and a horizontal end of the surface, and so that, in the region located on the horizontal axis, the horizontal radius of curvature is smaller than the vertical radius of curvature in a region near the horizontal end portion.

Abstract: The invention provides a novel color cathode ray tube apparatus incorporating an eight-pole permanent magnet means, and thereby deflective aberration of electron beams caused by deflected magnetic field can securely be minimized. Integral structure of a plurality of magnetic poles permits the concerned to easily form up the eight-pole permanent magnet ring.

Abstract: In a cathode ray tube, a first pair of permanent magnet pieces are arranged along a horizontal direction and fixed on an end portion of a deflection unit at an electron gun side in such a manner that poles of one of the magnet pieces face the other poles of the other magnet piece. A second pair of permanent magnet pieces are arranged along a vertical direction, separated from the first pair of permanent magnet pieces by being fixed on a neck portion, forward of the electron gun assembly, and in such a manner that poles of one of the, magnet pieces face the other poles of the other magnet piece.

Abstract: A degaussing current whose frequency is L Hz is supplied to a degaussing apparatus, and a constant amplitude vertical deflection current whose frequency is M Hz is supplied to a deflection yoke. The degaussing current is an A.C. current, and its frequency L Hz is determined such that the value of M/L is not an integer.

Abstract: Magnets for applying a pincushion type magnetic field to three electron beams emitted from an electron gun assembly is arranged between the deflection device and the lens unit of the electron gun assembly. The pincushion type stationary magnetic field produced by the magnets correct deflection aberrations of the electron beams due to the magnetic field of the deflection device and improves the focusing characteristics on the periphery of a screen.

Abstract: A color picture tube of this invention has a CRT envelope having a substantially rectangular front panel, a phosphor screen formed on an inner surface of the front panel, a shadow mask which is detachably mounted on the panel adjacent to the phosphor screen by a supporting assembly, and a frame surrounding the shadow mask. The supporting assembly has a plurality of stud pins which project from the four corners of the front panel and leaf springs which are fixed at one end to a corresponding corner of the frame are detachably engaged at the other end with a corresponding stud pin. Each leaf spring has an elastically deformable portion between one end portion fixed to the frame and the other end portion engaged with the corresponding one of the stud pins. Angle .beta., defined by the axis of the elastically deformable portion a central line axis of the CRT envelope, and angle .alpha.

Abstract: In a color cathode ray tube, a shadow mask and/or a panel is formed into the following shape. In the shadow mask and/or the panel, a radius of curvature at a central portion in a section taken along an X-Z parallel plane is larger than that at an effective diameter edge portion on the Y axis, and a radius of curvature at an effective diameter edge portion on the X axis is smaller than that at a diagonal effective diameter edge portion. In the panel, a difference between a thickness at an effective diameter edge portion and a thickness on the X axis in a section of the panel taken along a Y-Z parallel plane is maximum at a position between the center of the panel and the effective diameter edge portion on the X axis.

Abstract: In a color picture device having a tube envelope and an in-line type electron gun assembly disposed in a neck section of the tube envelope, a deflection unit includes a pair of first deflecting coils for deflecting three electron beams in a horizontal scanning direction coinciding with the in-line arranged direction, and a pair of second deflecting coils for deflecting the electron beams in a vertical scanning direction perpendicular to the horizontal scanning direction. A pair of permanent magnet plates is arranged individually between a funnel section and the second deflecting coils, and adapted to form a deflection magnetic field of a direction opposite to the vertical scanning direction.

Abstract: In a color picture tube in which an electron beam produced by an electron gun passes through apertures in a shadow mask structure and excites a phosphor screen, the shadow mask structure comprises a shadow mask having an electron beam penetration area and a frame portion supporting this shadow mask. The shadow mask is formed of a metal of a lower coefficient of thermal expansion than the frame portion. The shadow mask has its periphery bent to form a skirt portion and the skirt portion is fixed by welding to the frame inner wall. The skirt portion is subject to an inward compressive stress from the frame portion, and by means of this stress deformation during the manufacturing process and during operation is prevented.