Abstract: An electron gun comprises cathodes for emitting three electron beams, and grid electrodes forming at least two asymmetric electrostatic lenses along three electron gun axes. The lenses focus and deflect the electron beams to converge on a color cathode ray tube screen. The first asymmetric lens, in response to the focus voltage being varied, deflects the beam at a first angle and the second asymmetric lens deflects the beam at a second angle to compensate for the first angle deflection caused by the first asymmetric lens.

Abstract: A beam index color cathode ray tube is provided with a screen arranged on the inner surface of a face plate portion and an electron gun arranged in a neck portion thereof. This screen comprises phosphor stripes and index stripes. The electron gun comprises at least a cathode and two electrodes forming a focusing lens. The focusing lens of the electron gun is formed between at least two electrodes provided with transversely elongate openings having their direction of elongation in the width direction of the phosphor stripes or index stripes.

Abstract: The electron gun, which is especially adapted for use in color picture tubes, comprises in the order named: a cathode, an apertured-plate control grid (G1), an apertured-plate screen grid (G2), and at least two tubular focusing electrodes. The quality of the gun's beam spot is improved by: 1. Establishing an operating electric field between the G2 and G3 which is between about 100 and 400 volts/mil, thereby reducing aberration effects in the beam-forming region of the gun; 2. Making the G2 thick so as to prevent the high G3 voltage from penetrating the region between the G1 and G2, thereby allowing the G1-G2 field to provide a divergent effect on the electron beam prior to beam crossover and thus give a reduced crossover angle; 3. Spacing the main focusing lens at a distance from the G2 so as to provide an optimum filling of the main focus lens with the beam to maximize the object distance of the focusing system; and 4.

Abstract: An electron gun assembly of a cathode ray tube comprises in the order named, a cathode, an apertured modulator electrode, a first and a second apertured anode and a third cylindrical focussing anode. The modulator electrode and the first anode are supplied with such potentials as to form a crossover of electrons therebetween and the second anode is supplied with such a lower positive potential than at the adjacent first and third anodes that the electron stream emitted from the cathode is formed into a narrow beam of electrons and is allowed to enter the third anode at a small angle of beam spread and comes to a focus on the screen of the tube by the third anode to produce a spot of small cross-sectional area.

Abstract: In an electron gun for a cathode-ray tube of the type wherein a cathode, control grid electrode, an accelerating electrode and first and second cylindrical electrodes are disposed in the order named and supported and electrically insulated from each other by electrically insulating rods within a neck portion of an envelope, whereby a main electron lens is formed between said first and second cylindrical electrodes, the second cylindrical electrode comprises an enlarged diameter portion and a reduced diameter end portion which is closer to the cathode and is supported by one end of each of the supporting rods; and the first cylindrical electrode has (1) a neck portion which is extended through the reduced diameter end portion of the second cylindrical electrode coaxially thereof and radially inwardly spaced apart therefrom, and (2) an enlarged diameter front portion which has the diameter greater than that of said neck portion, is extended coaxially therefrom into said enlarged diameter portion of said second

Abstract: A cathode ray tube comprising an extra electrode with which the electron beam can be concentrated on a diaphragm aperture and simultaneously a small predeflection of the electron beam is obtained. The extra electrode is, for example, tubular and has oblique cut ends and is situated between two other electrodes. If the extra electrode has the same potential as the two other electrodes it is inoperative. If a suitable negative voltage pulse is supplied to the extra electrode the electron beam is slightly deflected and also concentrated on the diaphragm aperture.

Abstract: The gun, for use in a television picture tube, comprises a cathode, an apertured control grid, and an apertured screen grid aligned in the order named. The screen grid aperture comprises a rectangular slot portion facing the control grid and a circular portion facing away from the control grid. The slot portion of the aperture, which has a width 2-5 times its depth, creates an astigmatic field that produces underconvergence of the electron beam in the vertical plane only, whereby to avoid and/or compensate for vertical flare distortion of the beam spot at off-center positions on the image screen.

Abstract: An electron gun comprising a plurality of focusing grids spatially arranged along the path of an electron beam generated from a cathode and each bored with at least one opening for allowing the passage of the electron beam, wherein at least one of said plural focusing grids is formed of at least one electrode set at a grounding potential or a lower potential than a focusing voltage and at least one more electrode whose potential is defined by an electrostatic capacity; and a high voltage is produced to provide an electron lens, though enabling the electron lens to improve its performance without being obstructed by requirements associated with the construction of a picture tube.

Abstract: This disclosure depicts for use in a television picture tube having a bulb with a neck at the rear end thereof, a novel electron gun located in closely confined relationship in the neck. The gun has at least one cathode having an electron emissive coating, an apertured, substantially diamond-shaped shield cup with truncated corners and a plurality of electrodes interspaced between the cathode and the shield cup. The tube is characterized by the shield cup having one or more inward formations at one or more spaced locations around its periphery. The inward formations of the shield cup function to define one or more openings between the shield cup and the inner wall of the neck which act as cathode-erosion-suppressing by-pass vents during tube evacuation, and/or provide augmented deflection space for contact springs attached to selected opposite ones of said corners.

Abstract: In a unipotential type electron gun including a main lens constituted by three coaxial and spaced apart electrodes for focusing an electron beams, the length of the intermediate electrode is made to be larger than 1.1D, where D represents the inner diameter of the electrodes on both sides, and the sum of the length of one electrode located on the side of a cathode electrode, the length of the intermediate electrode, the gap length therebetween, and the gap length between the intermediate electrode and the electrode on the opposite side is set to be in a range of from 4.0D to 5.4D.

Abstract: This disclosure depicts an electron gun especially for use in a color cathode ray tube of the small-neck, shadow-mask type. The gun design is also applicable to other television cathode ray tube displays that require a gun that provides small, symmetrical spots of uniform cross-section, such as guns used in monochrome television and beam index tubes. The gun is comprised essentially of a four-element tetrode section and a main focus lens section. The tetrode section generates at least one electron beam and a cross-over that is imaged on the screen of the tube focused by the main focus lens. The tetrode section is characterized by having a strong prefocus; that is, a prefocus in which the electron trajectories are substantially refracted, or bent, before exiting the tetrode section.

Abstract: An electron gun comprising in succession in a vacuum envelope an electron source electrode or cathode, a control grid electrode, a first accelerating electrode or anode and a first and second focussing electrode. It further comprises connections for subjecting in operation each electrode to a polarizing voltage. The first focussing electrode is raised in operation to a polarizing voltage several tens of times higher than the polarizing voltage of the anode which precedes it and the second focussing electrode is raised in operation to a polarizing voltage several times higher than the polarizing voltage of the first focussing electrode which precedes it. The first focussing electrode and the anode form thus a prefocussing lens while the second focussing electrode and the first focussing electrode form a main lens.

Abstract: A color cathode ray tube includes an electron gun having a distributed lens system which yields smaller spot sizes on a phosphor screen at intermediate and higher cathode currents when compared with prior art electrostatic lenses having similar diameters. The lens establishes an essentially exponentially increasing potential distribution along the electron beam path.

Abstract: This disclosure depicts an electron gun for use in a color cathode ray tube of the small neck, shadow mask-type. The gun includes an extended field lens for generating a cluster of electron beams converged and individually focused at the screen of the tube. Three main focus lens means are situated on lens axes which are mutually parallel and parallel to a gun central axis. At least two of the lens axis are off-axis with respect to the gun axis. The focus lens means has for each beam at least three electrodes including a focus electrode for receiving a variable potential for electrically adjusting the focus of the beam. In succession down-beam, there are at least two associated electrodes having potentials thereon which forms in the gaps between adjacent electrodes significant main focus field components. To adjust beam focus, the strength of a first of these components is controlled by adjustment of the voltage received by the focus electrode.

Abstract: In an electron gun for use in a cathode ray tube of the class wherein a main electron lens system is constituted by a plurality of discrete electron lens systems, the plurality of electron lens systems are of the unipotential type and the intensity of the preceding lens system is made larger than that of the succeeding lens system.

Abstract: A cathode-ray tube with variable energy of electrons its beam formed by an electron accelerating means and an electron focusing means which are arranged in tandem along the beam axis. The electron focusing means comprises a magnetic lens with a constant magnetic-field intensity and an electrostatic lens so arranged with respect to the magnetic lens that defocusing of the electron beam by the magnetic lens, due to variations in the energy of the beam electrons, is compensated for. The electrostatic lens comprises two axisymmetric electrodes, the first electrode being electrically associated with the electron accelerating means, along the beam axis, and the second electrode being electrically associated with the screen of the cathode-ray tube.

Abstract: An electron gun apparatus comprises a cathode subassembly which is movably mounted relative to a fixedly mounted and registered grid/anode subassembly to permit mechanical adjustment of the cathode with respect to the grid/anode subassembly. An evacuated chamber, including resilient bellows interconnecting the movably mounted cathode assembly to the fixedly mounted grid/anode subassembly for permitting the mechanical adjustment, houses the cathode and the grid/anode subassemblies. Means are provided for electrical energization of the cathode, the grid, and the anode. According to a further feature of the invention, the cathode comprises a line filament, and the grid and the anode are slotted for providing an elongated line image.

Abstract: A television cathode ray tube has associated therewith a power supply for developing discrete supply voltages. A general purpose electron gun is depicted for receiving supply voltages from the power supply to produce a sharply focused beam of electrons at the cathode ray tube screen. The gun comprises associated cathode means and grid means for producing a beam of electrons, and novel focus lens means. The focus lens means receives electrons from the cathode means and a predetermined pattern of voltages from the power supply and comprises at least three electrodes for establishing a single, continuous electrostatic focusing field characterized by having an axial potential distribution which, at all times during tube operation, decreases smoothly and monotonically from a relatively intermediate potential to a relatively low potential spatially located at a lens intermediate position, and then increases smoothly, directly and monotonically from said relatively low potential to a relatively high potential.

Abstract: In an electron gun for use in a cathode ray tube of the class wherein a main electron lens system is constituted by a plurality of discrete electron lens systems, the plurality of electron lens systems are of the unipotential type and the intensity of the preceding lens system is made larger than that of the succeeding lens system.

Abstract: A color television picture tube electron gun with an astigmatic lens element formed as an integral part of the second electrode. The astigmatic lens is a rectangularly configured ridge formed in the end closure surface of the second electrode, about a centralized circular aperture. The dimensions are selected to optimize the electron beam configuration impinging upon the screen of the picture tube with the beam being elongated a predetermined amount in the direction normal to the raster sweep direction.

Abstract: An internal improvement is provided in a cathode ray tube wherein the electron gun assembly is positioned in close proximity to the sidewall of the encompassing neck portion of the tube envelope. The improvement is in the form of discrete shielding means incorporated in conjunction with one or more electrodes in the forward portion of a multi-beam electron gun assembly to minimize the effect of positive neck charge on the trajectories of the electron beams traversing the portions of the assembly closely related to the neck wall. Each shielding means is comprised of an element formed of substantially round wire material configurated as a U-shaped member, whereof the bottom bridge-portion of the member is substantially contiguous with the rolled rim of the associated electrode, extending outward therefrom toward but not touching the adjacent glass wall of the neck.

Abstract: A cathode-ray tube having electrostatic focusing and electrostatic deflection lens which comprises three cylindrical electrode arranged along a common axis. The end electrodes are supplied by a high focusing voltage and the intermediate electrode is divided into at least three segments, each being supplied by a voltage which is a linear combination of a lower focusing voltage and of two deflection voltages.

Abstract: In the tube gun, the apertures of the two grids closest to the cathodes are vertically elongated or, preferably, vertically elliptically shaped to provide at least partial compensation for beam distortion occuring in a deflection zone of the tube.

Abstract: A cathode ray tube is disclosed in which an electron beam is deflected to scan a phosphor screen for producing a picture thereon, and which has an electrostatic beam control device for deforming the cross section of the beam so as to compensate for the distortion in shape of the beam landing spot on the screen at its peripheral portion caused by the beam deflection and a magnetic beam control device for deforming the cross-section of the beam dynamically in response to the beam deflection so as to compensate for the distortion in shape of the beam landing spot on the screen at its central portion caused by the electrostatic beam control device.

Abstract: A field emission gun for use in an instrument such as an electron microscope including the field emission tip, an extraction electrode and focusing and accelerating anode means wherein there is disposed between the tip and the accelerating field of the anode means an electric field of a strength expressed in terms of electron voltage, at least equal to the lowest energy secondary electron sought to be prevented from entering the accelerating field.