Abstract: A color picture tube in which an electron gun emits three electron beams arranged in line, in which the diameter of the spot (26) at the center of the screen in the in-line direction is smaller than that in the direction perpendicular to the in-line direction when the spot is in a just-focused state. Therefore the shape of the spot (27) at the periphery of the screen is generally a true circle. As a result, the resolution at the periphery of the phosphor screen is improved, and the more is suppressed.

Abstract: A color picture tube apparatus having a system for increasing an upper and lower pincushion distortion in the peripheral portion in the vertical direction by making the preliminary vertical deflection force when an electron beam is deflected toward the peripheral portion in the vertical direction of a phosphor screen relatively smaller than the preliminary vertical deflection force when an electron beam is deflected toward the middle portion in the vertical direction of the phosphor screen. With the color picture tube apparatus using an S-shaped distortion correction circuit, an upper and lower inner pincushion distortion can be optimized while correcting the upper and lower pincushion distortion.

Abstract: A set of three cathodes, a control electrode, an accelerating electrode, a first focus electrode, a second focus electrode, a third focus electrode, a fourth focus electrode, a final accelerating electrode and a shield cup electrode are provided successively in an electron beam travelling direction. The shield cup electrode has a pair of screen-shaped electrodes that sandwich electron-beam through-holes in a vertical direction. A quadrupole lens that has a horizontal convergent action and a vertical divergent action is generated by an electrical potential difference between the screen-shaped electrodes and the final accelerating electrode. Accordingly, even if vertical and horizontal convergence power difference in a main lens formed by the fourth focus electrode and the final accelerating electrode is not large, a composite lens formed through a combination of the quadrupole lens and the main lens has strong horizontal convergence power and weak vertical convergence power.

Abstract: In an electron gun for a color cathode ray tube apparatus of this invention, one intermediate electrode is arranged between a final acceleration electrode and a focus electrode that make up a main lens, and a voltage divided by a voltage dividing resistor for dividing a voltage to be applied to the final acceleration electrode is applied to the intermediate electrode. A dynamic voltage which increases along with an increase in deflection amount of an electron beam is applied to the focus electrode, and a dielectric portion is formed between the final acceleration electrode and the focus electrode. This dielectric portion is formed on the intermediate electrode. Hence, elliptical distortion of electron beam spots is decreased on the entire surface of a phosphor screen, thereby providing a color cathode ray tube apparatus with a good performance on the entire surface of the phosphor screen.

Abstract: An in-line electron gun for a colored cathode ray tube has an electronic field correction plates with a central key-hole shaped aperture with two opposite straight lines and two side apertures each with a plurality of vertical and horizontal in addition to a plurality of circular arcs of different radii.

Abstract: A magnetic shield (20) for a cathode ray tube includes a body portion and a skirt section (21) around the body portion. The skirt section (21) has a skirt portion (23) having a free edge (25) and being connected to the body portion at its opposite edge (26), wherein the length of the free edge (25) is less than the length of the opposite edge (26).

Abstract: A CRT for the display of a large screen television set which includes a tube envelope having a pair of tube necks and a phosphor display screen, a pair of electron guns arranged in a same horizontal plane and each positioned in a different one of the tube necks, for directing dual electron beams to impinge upon the phosphor display screen, and magnetic deflection yokes for horizontally deflecting the dual electron beams to produce a visual display of partially overlapping dual raster scans on the display screen.

Abstract: An electron gun assembly forms an electron beam generator, pre-focusing lens, sub-lens, and main lens. The sub-lens has a weaker horizontal focusing power than the vertical one, and the main lens has a stronger horizontal focusing power than the vertical one. When the electron beam is not deflected, a first quadrupole lens is formed between the pre-focusing lens and sub-lens, and a second quadrupole lens is formed between the sub-lens and-main lens. At least one grid forming each of the first and second quadrupole lenses receives a dynamic focusing voltage which parabolically changes in synchronism with the deflection magnetic field and becomes higher when the electron beam is deflected than when it is not deflected.

Abstract: An electron gun which emits three electron beams consisting of a center beam and paired side beams arranged in line in the horizontal axis is arranged in the neck of the vacuum envelope. A neck-side orbital correction coil unit for over-converging the side beams running toward the peripheral portion of a phosphor screen and a panel-side orbital correction coil unit for under-converging the side beams running toward the peripheral portion of the phosphor screen are provided between the cathode of the electron gun and the phosphor screen. The panel-side orbital correction coil unit has four orbital correction coils provided inside the magnetic core of a deflection yoke. Each orbital correction coil includes paired coil wires extending in the tube axis direction. One of the coil wires is positioned at an angle of 10 to 30° to the vertical axis, and the current flows from the neck side toward the panel through this coil wire.

Abstract: A compensation device for convergence drift used in a CRT, including a convergence electrode attached on an outer surface of a neck portion, an inducement means for inducing static electricity from a voltage to be supplied for an inner graphite layer, and a connecting member formed between the convergence electrode and the inducement means to supply high potential from the inducement means to the convergence electrode. As the convergence electrode provides high potential generated from the inducement means to the neck portion, the compensation device decreases the potential difference between grid electrodes and the neck portion. Thus, the compensation device makes the electric fields, which cause the charges to be accumulated, to weaken so that the convergence drift is effectively reduced.

Abstract: A vertical deflection system for a CRT is disclosed which has a pair of traveling wave deflectors disposed opposite each other across a path of beam from gun to target. Each deflector has a helical conductor in the for of a strip of sheet metal coiled around an elongate core of insulating material. For the provision of a CRT capable of handling a wide band of frequencies, the dispersion characteristic of each traveling wave conductor is optimized through adjustment of the specific dielectric constant of the insulating core. Preferred values of the specific dielectric constant are specified in relation to the characteristic impedance of the traveling wave conductor.

Abstract: A deflection yoke for a cathode ray tube can correct both the pincushion distortion at the upper and lower edges of the screen and the misconvergence of the screen at the same time by the deflection yoke itself without the need for a correction magnet. The deflection yoke comprises a saddle shaped horizontal deflection coil, a saddle shaped vertical deflection coil located outside the horizontal deflection coil, and a high permeability core located outside the vertical deflection coil. The core has notch portions at the center parts of the upper and lower portions of the screen side end.

Abstract: A rigid ferrite-containing ring and plastic holder are described for mounting on the neck of a color cathode ray tube (CRT) which ring is to be custom magnetized in order to provide correction of static convergence, color purity and/or frame errors in the CRT. The holder is provided with depressible tabs which releasably secure the ring to the holder. The holder is mounted on the neck of the CRT in the vicinity of the main focusing gap of the electron gun of the CRT, using an adhesive.

Abstract: A deflection yoke for a cathode ray tube can correct both the pincushion distortion at the upper and lower edges of the screen and the misconvergence of the screen at the same time by the deflection yoke itself without the need for a correction magnet. The deflection yoke comprises a saddle shaped horizontal deflection coil, a saddle shaped vertical deflection coil located outside the horizontal deflection coil, and a high permeability core located outside the vertical deflection coil. The core has notch portions at the center parts of the upper and lower portions of the screen side end.

Abstract: A deflection yoke is comprised of a pair of separators 1a, 1b. A cylindrical neck 3 is formed on the pair of separators. Magnetic rings 7, 8, 10, 11 are installed on the neck. A spacer 19 is inserted between the magnet rings 8 and 10. A clamp band 5 is installed on the cylindrical neck, and fastens the deflection yoke to a neck of a cathode ray tube. The spacer has protuberances 19a, 19b. Projections 20a, 20b are formed on the pair of separators so as to engage with the protuberances for restricting rotation of the spacer.

Abstract: A color cathode ray tube device is provided in which the generation of the trapezoidal distortion of a rectangular raster is controlled and an off-axis misconvergence is corrected to obtain high image quality in the peripheral portion of a screen. An annular ferrite core is provided adjacently to the electron gun side end face of a ferrite core of a deflection yoke so as to b decentered radially within the predetermined range around the central axis of the deflection yoke in the tube axial direction. An asymmetric magnetic field is formed on the electron gun side of the deflection yoke by the annular ferrite core which has been decentered. Thus, the off-axis misconvergence can be corrected while controlling the generation of the trapezoidal distortion.

Abstract: There is provided a picture distortion correcting apparatus for correcting substantially improves a magnetic field correcting effect in which a special picture distortion corrected even when the same magnet volume as a conventional magnet is used. Rod-shaped magnets for correcting picture distortion are attached on the outside of a cathode ray tube corresponding to the upper and lower screen portions. Both the magnetic poles of the rod-shaped magnets 26 and 28 are bent toward the tube axis of the cathode ray tube. The transverse cross section of the rod-shaped magnet may have an inverse U shape. By making both the magnetic poles bent toward the tube axis of the cathode ray tube, the magnetic field correcting effect is improved, and a special picture distortion can be corrected effectively without making the magnet larger and without using a plurality of magnets.

Abstract: A color cathode ray tube equipped with an in-line type electron gun, a deflection yoke designed to generate a uniform deflection magnetic field, the in-line type electron gun having a focusing grid which accommodates three pole pieces of magnetic bodies, and a magnetic field generator disposed outside the cathode ray tube so as to apply 4-pole dynamic magnetic fields to the pole pieces, thus constituting a dynamic convergence system capable of correcting any misconvergence of the three electron beams in a vertical direction or a horizontal direction.

Abstract: A convergence correcting magnet assembly means for adjusting the position of plural correcting magnets closer to or further from electron beams in a cathode ray tube, preferably comprising four bipolar magnets arranged in two offset pairs, one pair oriented in the lateral direction and a second pair in the longitudinal direction; the pairs of magnets permit laterally and longitudinally deviating beams to be adjusted or converged toward the center beam. Preferably, each of the bipolar magnets is installed in a clearance space having a spring-loaded or elastic member and an adjusting member, so that the intensities of each magnet can be adjusted by individually moving each magnet closer to or further from the beams under spring tension. Interactions between the magnets are minimized by isolating the magnets from one another.

Abstract: A deflection yoke device for deflecting an electron beam traveling in the interior of a CRT. The distribution of a magnetic field supplied by horizontal deflection coils to the interior of the CRT forms a barrel magnetic field on the panel side and the neck side, as viewed from the horizontal deflection coils, and a pin magnetic field in an intermediate space therebetween. The deflection yoke device of the invention is provided with a correction coil on the neck side, as viewed from the horizontal deflection coils so as to correct the neck-side magnetic field produced by the horizontal deflection coils into the barrel magnetic field of a greater intensity. The distortion of a beam focus caused by the pin magnetic field is thereby corrected.

Abstract: An image display device includes comb-shaped horizontal deflection electrodes disposed interleavingly in a first plane with a space therebetween for forming electron beam passages and comb-shaped vertical deflection electrodes disposed interleavingly in a second plane adjacent and parallel to the first plane. The capacitance between the horizontal deflection electrode confronting the vertical deflection electrodes and the capacitance between the horizontal deflection electrode confronting the vertical deflection electrode are made equal to each other. Also, the capacitance of the vertical deflection electrode confronting the horizontal deflection electrodes and the capacitance of the vertical deflection electrode confronting the horizontal deflection electrodes are made equal to each other, whereby the voltage effect induced by the other deflection electrode can be canceled and a good quality image can be obtained.

Abstract: A projection lens assembly (10) projects onto a display screen (38) electrons emitted from an output side (86) of an electron multiplier such as, for example, a microchannel plate (70). The projection lens assembly includes a dome-shaped mesh element (16) that is concave as viewed from the display screen. The mesh element is positioned between the microchannel plate and a filter element (20) having a beam-limiting aperture (22). The mesh element is of an aspherical shape that allows the projection lens assembly to project the electrons toward the display screen with substantially no spherical aberration, thereby forming near the beam-limiting aperture an electron beam crossover of small diameter. The beam-limiting aperture is formed with a relatively small diameter that allows the filter element to block electrons of energies outside a preselected range of energy values, thereby reducing chromatic aberration in the image formed on the display screen.

Abstract: A charged-particle beam tube having an envelope of a dielectric material and a pattern yoke formed on the inner surface of the envelope. The pattern yoke has a pair of horizonal deflection electrodes and a pair of vertical deflection electrodes arranged alternately. The horizontal deflection electrodes have a greater circumferential width than the vertical deflection electrodes. The horizontal and vertical deflection electrodes are supplied with different bias voltages.

Abstract: A traveling-wave deflection system comprising a pair of deflectors disposed opposite each other across the path of an electron beam from an electron gun to a screen in a cathode-ray tube. Each deflector has a helical conductor wound around a core structure generally extending along the beam path. If made solely of an insulating material as in the prior art, the core structures would be electrified in use of the CRT, with the consequent deflection defocusing and bright line displacement. Therefore, in order to avoid electrification, the core structures are each enveloped in an antielectrification layer of a conducting material having a higher resistivity than the helical conductor. An embodiment is also disclosed wherein the core structures are wholly of conductive material.

Abstract: A magnetic cancelling apparatus for a color cathode-ray tube which is to cancel external magnetic fields acting on the color cathode-ray tube, can prevent deterioration of the screen color purity. The apparatus includes a magnetic sensor for detecting a magnetic field in a predetermined direction acting on the cathode-ray tube. The output of the magnetic sensor is amplified and then fed to a cancelling coil, thereby permitting the screen purity to be kept in best condition even under change in direction of the external magnetic field such as the geomagnetism.

Abstract: In an electron gun assembly of an in-line type, electron beams emitted from cathode pass through first, second and third grid electrodes and are accelerated and controlled by the electrodes. The accelerated and controlled electron beams are converged by a fourth grid electrode structure and are also focused on the phosphor screen by fifth and sixth grid electrodes. The fourth grid electrode structure is comprised of first to third electrode segments having apertures through which electron beams pass. The first and third electrode segments is maintained at a variable potential which is varied in accordance with a deflection of the electron beams and the second electrode segment is maintained at a constant potential.

Abstract: Picture display device having a display tube (3) and a deflection unit (9) comprising a field deflection coil and a line deflection coil (11). To comply with a predetermined interference radiation standard, the picture display device comprises a first set of (horizontal) interference suppression coils 18, 19 arranged symmetrically relative to the plane of symmetry of the line deflection coil and a second set of (vertical) interference suppression coils 18a, 19a arranged at right angles to the plane of symmetry of the line deflection coil, which coils are oriented in such manner and in operation are energizable in such manner that, measured at a predetermined distance from the picture display device, at least the strength of the local magnetic dipole field is below a desired standard. Each coil of the second set preferably comprises at least two sub-coils arranged parallel to each other at a given distance in order to reduce the energy content of the coil system.

Abstract: In a color cathode ray apparatus, three electron beams emitted from electron gun assembly are correctly converged on a peripheral region of a peripheral region of a phosphor screen and are weakly converged on a center region of the phosphor screen by static convergence means. The electron beams are also converged by dynamic convergence means so as to correct the weak convergence in accordance with a horizontal deflection of the electron beams. Thus, the electron beams can be correctly converged all over the phosphor screen.

Abstract: Apparatus for correcting astigmatism produced by the electromagnetic deflection yoke of a cathode-ray-tube includes stigmator electrodes provided with elongated slots through which the cathode-ray-tube's electron beam or beams pass. Appropriate correction voltages, stored in digital memory, are applied to the stigmator and focus electrodes for bringing about re-focusing of the electron beam in appropriate axes for restoring a single point focus.

Abstract: An image display apparatus for displaying images on a fluorescent screen comprising plural linear cathodes, an electron beam extraction electrode with plural apertures and vertical deflection electrodes which are formed by segments. The respective segments of the vertical deflection electrodes have various shapes, and deflection voltages applied to the respective segments can be varied so that distortion of the displayed images on the fluorescent screen may be corrected.

Abstract: A cathode-ray tube which has an electron gun and a correcting unit with a magnetic device electrically coupled to a final electrode of the electron gun so as to selectively apply a uniform magnetic field to required ones of a plurality of electron beams, so as to thereby correct the path of a selected electron beam without causing distortion in the shape of the beam spot.

Abstract: An electron gun for a color picture tube has at least a cathode, a control grid, an accelerating grid, a focus grid and an anode, each of which has three apertures aligned in line. The focus grid and the anode made of elongated plates serves as main lens electrodes, and the apertures of the focus grid and the anode constitute a main lens assembly. The three apertures of each of the elongated plates has a central aperture defined by two first curves arcuated outward, two side apertures each of which is defined by a second curve as an inner half arcuated inward and a third curve as an outer half arcuated outward, the first and second curves being less arcuated than the third curve. The three apertures are aligned such that the major axes thereof are parallel to a shorter axis of the elongated plate and are located at equal intervals. The three apertures are spaced apart from each other through corresponding bridge portions.

Abstract: An in-line color picture tube including a deflection unit having a system of deflection coils accommodating two sets of soft magnetic correction elements. The first set is provided in the proximity of the center of the vertical deflection field and symmetrically with respect to the plane through the non-deflected electron beams. The second set is also provided in the proximity of the center of the vertical deflection field, but closer to the entrance side thereof and symmetrically with respect to the plane through the tube axis which is at right angles to the plane through the non-deflected electron beams. The second set of correction elements is thereby angularly rotated 90.degree. relative to the first set of correction elements. The first set provides conventional astigmatism correction, and the second set provides astigmatism correction of higher order components of the deflection field.

Abstract: A technique for correcting spherical and other aberrations in a particle beam. Spherical aberration is caused by variations in beam behavior dependent on the cube of the radius or radial position with respect to the beam axis. To correct for such aberration, the beam is passed through multiple compensation electric field arrays, each of which has multiple rows of parallel wires stretched transversely across the beam path, the rows being biased with separate voltages to provide an electric field that varies in proportion to the cube of the distance from the central row of the array. The multiple arrays provide a cylindrically symmetrical electric field, and are oriented at a uniform angular spacing, which, for spherical aberration, is 120 degrees.

Abstract: Apparatus for correcting astigmatism produced by the electromagnetic deflection yoke of a cathode-ray-tube includes plural stigmator electrodes provided with elongated slots through which the cathode-ray-tube's electron beam passes. Appropriate correction voltages, stored in digital memory, are applied to the stigmator and focus electrodes for bringing about re-focusing of the electron beam in appropriate axes for restoring a single point focus on the cathode-ray-rube's screen.

Abstract: By application of a predetermined period of relatively higher magnitude of electron beam emission from the cathode of the electron gun to the anode maintained at high voltage the potential gradient on the inside of the neck portion of a cathode ray tube is stabilized and the phenomenon of electron beam drift is thus suppressed effectively.

Abstract: To correct the beam direction, and thus the color purity of color television tubes, particularly in tubes having fixedly secured deflection systems (10), the deflection field is, upon adjustment for color purity, additionally modified by introducing a unidirectional magnetic field extending with its field lines parallel to the z-axis of the tube. After adjustment to move a predetermined color, for example red, from non-deflected or hardly deflected central beam positions into the center of the CRT, the d-c unidirectional field is then disconnected, and the apertured mask demagnetized, as conventional. For demagnetization, the already present demagnetization coil (9) on the tube may be used, by applying a constant voltage thereto, for example of 12 V. The decaying demagnetizing field can be derived from a transformer connected to network power (FIG. 2) or through an oscillatory circuit formed by a charge capacitor (17).

Abstract: A cathode ray tube including, in an evacuated envelope, at least one electron gun to generate an electron beam directed onto a target, and first and second pairs of deflection plates for deflecting the electron beam in two mutually perpendicular directions. Various defects in the displayed image are corrected by providing at least one ring of magnetizable material, permanently magnetized as a multipole, between the first pair of deflection plates and the target.

Abstract: In an electron-optical system of the mixed field type in which magnetic and electric fields are respectively operative to project a focused image of an object of the system upon a target structure and to simultaneously scan such image across the target structure, beam landing errors are eliminated by dimensioning and locating the solenoid for generating the magnetic field and the electrostatic yoke for generating the electric field so that the landing errors due to non-uniformity of the electric field, for example, by reason of field-free regions at the opposite ends thereof, are substantially cancelled by landing errors due to non-uniformity of the magnetic field, for example, as constituted by flare field regions at the opposite ends of the magnetic field.

Abstract: A cathode ray tube includes first and second electrostatic quadrupole lens between the electron gun and the vertical deflection plates to properly focus the electron beam before it enters the vertical deflection plates. A third electrostatic quadrupole lens is located between the vertical deflection plates and the horizontal deflection plates to enhance the angle of deflection as well as to properly focus the electron beam as it moves from the vertical deflection plates into the horizontal deflection plates. A meshless scan expansion lens follows the horizontal deflection plates and is formed of aligned tubular members having interdigitated sections thereby forming a fourth quadrupole lens which accelerates the electron beam and expands it prior to being impinged onto the fluorescent screen.

Abstract: A cathode ray tube includes first and second electrostatic quadrupole lens between the electron gun and the vertical deflection plates to properly focus the electron beam before it enters the vertical deflection plates. A third electrostatic quadrupole lens is located between the vertical deflection plates and the horizontal deflection plates to enhance the angle of deflection as well as to aid in the proper focus of the electron beam as it moves from the vertical deflection plates into the horizontal deflection plates thereby providing substantially improved vertical sensitivity and scan expansion of the electron beam while maintaining the beam velocity constant.

Abstract: A dual-beam cathode-ray tube having a pair of electron guns and associated deflection means disposed side-by-side on each side of a central axis is described in which the electron guns are parallel and the deflection means includes beam centering plates and angled horizontal deflection plates to direct the electron beams toward the central axis, precluding the need for a large-diameter tube neck in which the entire gun structures are angled. Bowing control plates are disposed adjacent the beam centering plates to minimize trace bowing, and an intergun shield is disposed between the horizontal deflection plates to control and correct display pattern geometry distortion.

Abstract: A storage cathode-ray-tube having a single off-axis flood gun is described including auxiliary coils defining electromagnets placed, one electromagnet on either side of the cathode-ray-tube to correct non-symmetrical geometry in optical representations produced on the fluorescent screen of the cathode-ray tube caused by interaction of the conventional principle electron beam under the control of electrical signals during storage operation.