Abstract: Disclosed are techniques and apparatuses for transmitting positioning beacon beams including transmitting a plurality of positioning beacon beams from a first node in a first time period using a first order of transmission. Then, the first node transmits the plurality of positioning beacon beams from a second time period using a second order of transmission, where the first order of transmission is different in the second order of transmission.

Abstract: In an atom probe having a specimen mount spaced from a detector, and preferably having a local electrode situated next to the specimen mount, a lens assembly is insertable between the specimen (and any local electrode) and detector. The lens assembly includes a decelerating electrode biased to decelerate ions from the specimen mount and an accelerating mesh biased to accelerate ions from the specimen mount. The decelerating electrode and accelerating mesh cooperate to divert the outermost ions from the specimen mount—which correspond to the peripheral areas of a specimen—so that they reach the detector, whereas they would ordinarily be lost. Because the detector now detects the outermost ions, the peripheral areas of the specimen are now imaged by the detector, providing the detector with a greatly increased field of view of the specimen, as much as 100 degrees (full angle) or more.

Abstract: An electron gun includes: an electron source; an accelerating electrode; an extraction electrode for extracting electrons from an electron emission surface of the electron source; a suppressor electrode for suppressing emission of electrons from a side surface of the electron source; and an electron beam converging unit for converging an electron beam of thermal field emission electrons emitted from the electron emission surface by applying an electric field to the electron emission surface. The electron beam converging unit is an electrostatic lens electrode which is placed between the extraction electrode and the accelerating electrode and having an opening portion in its center. A voltage is applied to the electrostatic lens electrode to converge the electron beam.

Abstract: An electron gun includes: an electron source; an accelerating electrode; an extraction electrode for extracting electrons from an electron emission surface of the electron source; a suppressor electrode for suppressing emission of electrons from a side surface of the electron source; and an electron beam converging unit for converging an electron beam of thermal field emission electrons emitted from the electron emission surface by applying an electric field to the electron emission surface. The electron beam converging unit is an electrostatic lens electrode which is placed between the extraction electrode and the accelerating electrode and having an opening portion in its center. A voltage is applied to the electrostatic lens electrode to converge the electron beam.

Abstract: An electron gun includes a cathode adapted to emit thermal electrons, a first electrode and a second electrode adapted to form a triode portion together with the cathode, a plurality of focusing electrodes, each of said plurality of focusing electrodes being perforated by a plurality of beam passage apertures and an anode electrode, wherein a pitch between ones of said plurality of beam passage apertures of a one of said plurality of focusing electrodes arranged closest to the second electrode is smaller than a pitch between ones of said plurality of the beam passage apertures of a remaining of said plurality of focusing electrodes.

Abstract: A plurality of magnet rings for correcting a convergence are arranged in a tube axis direction with spacers interposed therebetween, on an outer circumferential surface of a neck. A velocity modulation coil for modulating a scanning velocity in a horizontal direction of an electron beam is placed so that a position of the velocity modulation coil in the tube axis direction is overlapped with those of the magnet rings. At least one of the spacers is made of only a magnetic substance. Alternatively, at least one of the spacers is made of a magnetic substance, and the outermost surface in a radius direction of the spacer made of a magnetic substance is covered with a non-metallic material. Because of this, the magnetic field formed by the velocity modulation coil can be intensified without disturbing the magnetic field of the magnet rings of a CPU.

Abstract: A deflection yoke includes ferrite core, horizontal deflection coil, vertical deflection coil, and insulating frame for insulating the horizontal and vertical deflection coils. The deflection yoke has a cross section that satisfies the following A to C. A: A plurality of magnetic substance convex portions projecting toward the tube axis are provided in the vicinity of a position of an inner surface of the ferrite core where a vertical axis crosses. B: Assuming that a minimum value among distances between the respective magnetic substance convex portions and a funnel is D1, the distance between the ferrite core excluding the plurality of magnetic substance convex portions and the funnel is larger than the distance D1 at any point of the ferrite core. C: A part of the vertical deflection coil is wound in a groove between the plurality of magnetic substance convex portions.

Abstract: The present invention relates to a color cathode ray tube and electron gun, and more particularly, to a color cathode ray tube and electron gun to improve deflection aberration efficiently using magnetic material formed at the electron gun and to improve a resolution of a display screen.

Abstract: An electron gun for a color CRT includes a main focusing lens unit that focuses the electron beams generated by a triode unit. The main focusing lens unit includes a first and a second electrostatic screen grid having three electron beam through holes linearly-arranged for passing three electron beams, two of the holes being external and an oval shaped hole that passes all three electron beams. The oval shaped holes being spaced a distance, d1 and d2, respectively, from the through holes. Furthermore, the first grid external holes have an external distance HL1 and an internal distance HR1 and the second grid external holes have an external distance HL2 and an internal distance HR2; and wherein HL1 is greater than HR1, HL2 is greater than HR2, d1 is greater than d2, HL2 is greater than HL1, and HL2+HR2 is greater than HL1+HR1.

Abstract: An electron gun assembly that emits three electron beams, which are arranged in line, toward a phosphor screen includes three cathodes arranged in line, three first grids arranged to face the associated cathodes, and a second grid with an integral structure that is disposed to face a phosphor screen side of the first grids. Each of the first grids is formed of a cup-shaped electrode body having an electron beam passage hole. The electron gun assembly further includes an insulation member through which the three first grids penetrate, the insulation member thus integrally holding the three first grids, a cylindrical member that surrounds the insulation member and has an implant part, and an insulating support member that supports the implant part of the cylindrical member.

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: Provided are a display device, and more particularly, a display device shared between a digital-to-analog converter for outputting a convergence signal and a digital-to-analog converter for outputting a dynamic focus signal, in a projection television using 3 cathode-ray tube projection optics.

Abstract: An electron gun for a cathode ray tube includes a cathode for radiating electron beams, a scanning velocity modulation coil for synchronizing the electron beams with an image signal, a focus electrode having first and second sub-electrodes disposed with a gap through which a magnetic field generated by the scanning velocity modulation coil passes, a plurality of grid electrodes with the focus electrode for controlling the electron beams radiated from the cathode, a support for aligning and supporting the grid electrodes, and a shield electrode electrically connected to the first and second sub-electrodes to protect against infiltration of an outer electric field. The shield electrode includes plural intermediate electrodes disposed in the gap between the first and second sub-electrodes, and electrical connecting unit for electrically connecting the intermediate electrodes to the first and second sub-electrodes. The intermediate electrodes are spaced away from each other.

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: A color picture tube device has a funnel glass, a pair of horizontal deflection coils, an insulating frame, and a pair of vertical deflection coils. The pair of horizontal deflection coils are opposed to each other in a vertical direction around the outer surface of the funnel glass, and each have a window at the center. The insulating frame covers the horizontal deflection coils, resembles in shape a part of the funnel glass where the horizontal deflection coils are provided, and has openings in areas corresponding to windows of the horizontal deflection coils. The pair of vertical deflection coils are opposed to each other in a horizontal direction around the outer surface of the insulating frame, without overlapping the openings. A pair of correction coils are provided so as to be each at least partially inserted in a different one of the openings.

Abstract: A color picture tube device that can adjust convergence without causing increases in cost and in power consumption is provided. One pair of magnetic flux generation means for generating a static quadrupole magnetic field are positioned above and below an area where a plurality of electron beams pass through. The static quadrupole magnetic field has an effect of adjusting convergence in a horizontal direction. In this construction, a magnetic flux generated by one of the two magnetic flux generation means that is closer to the plurality of electron beams is reduced, in sync with deflection of the plurality of electron beams in a vertical direction.

Abstract: The present invention relates to a display device comprising a cathode ray index tube (1) having a neck portion (1?) and a screen portion (1). The display device comprises an electron gun assembly (3) for generating a plurality of electron beams (3R,3G,3B), positioned in the neck portion (1?) of the cathode ray index tube (1), a deflection unit (5), placed around the neck portion (1?) of the cathode ray index tube (1), for deflecting said plurality of electron beams (3R,3G,3B), and a convergence unit (6) for converging said plurality of electron beams (3R,3G,3B). The deflection unit (5) is placed at an axial distance from said electron gun assembly (3), closer to said screen portion (1?). The convergence unit (6) is placed in close proximity to the deflection unit (5).

Abstract: In an electron gun including a cathode, a control electrode, an acceleration electrode G2, a focusing electrode G3 and an anode, longitudinally elongated concave SL-V which surround an electron beam aperture G2-H and have a long axis in the vertical direction is formed at a focusing electrode G3 side of the acceleration electrode G2, and an electron beam aperture G3-BH formed at the acceleration electrode G2 side of the focusing electrode G3 is formed in a longitudinally elongated shape having a long axis in the vertical direction. Due to such a constitution of the present invention, non-uniformity of the beam spot shape attributed to a deflection quantity can be reduced whereby the optimum focusing can be realized over the whole area of a screen.

Abstract: The present invention relates to a cathode ray tube, and more particularly, to a cathode ray tube with reduced stray emissions by improving the electrical conductivity of an electrode material of an electron gun housed in a funnel of the cathode ray tube.

Abstract: The invention relates to a color display device comprising an electron gun (5) for generating three electron beams (6,7,8), and convergence means (14) for dynamically influencing the convergence of the electron beams. The convergence means (14) comprise coils (22) for generating a magnetic field. The coils (22) are provided with an electrically conducting layer.

Abstract: An electron gun for a cathode ray tube and a cathode ray tube using such electron gun is provided. The electron gun includes a cathode for emitting an electron beam; a plurality of grid electrodes aligned sequentially from the cathode, one of the grid electrodes including a plurality of focusing electrodes that are mounted with a predetermined gap therebetween; a support for fixing the grid electrodes in their aligned arrangement; and a shield electrode mounted covering the gap(s) of the focusing electrodes and extending a predetermined distance over the focusing electrodes. The cathode ray tube includes the electron gun; a neck, within which the electron gun is mounted; and a scanning velocity modulation coil mounted on an outer circumference of the neck corresponding to the positioning of the gap(s) of the focusing electrodes.

Abstract: A cathode ray tube includes a display for presenting an image, a deflection device, and an electron gun including electron-generating cathodes for generating electron beams. The CRT includes an electron beams controller for varying the trajectory of at least a first electron beam of the electron beams as a function of the intensity of at least the first electron beam, in order to compensate for changes in the convergence angle between electron beams near the display. The electrom beam controller is arranged between the electron-generating cathodes and the deflection device.

Abstract: A color picture tube device that can suppress the deformation of the electron beam spot shape and improve the horizontal resolution using a simple construction is provided. A horizontal deflection coil generates a horizontal deflection magnetic field that is substantially uniform. A plurality of electron beams are substantially parallel with the tube axis when passing one end of a core of a deflection yoke facing an electron gun. A lens forming unit forms a lens through which the plurality of electron beams pass, between the electron gun end of the core and a phosphor screen. The lens has an effect of causing the plurality of electron beams to approach each other in a horizontal direction, irrespective of which part of the phosphor screen the plurality of electron beams reach.

Abstract: A display device comprising a deflection unit and a cathode ray tube having an in-line electron gun. The electron gun comprises a main lens portion having means for generating a main lens field and an auxiliary field. Furthermore, the electron gun comprises a prefocusing lens portion having a first, a second and a third electrode for generating a prefocusing lens field. In operation, in a direction perpendicular to the in-line plane, the auxiliary field and the main lens cause the electron beam to leave the main lens substantially parallel to the in-line plane, whereby the diameter of the electron beam at a gap of the main lens at the anode side is smaller than or equal to the diameter of the aperture of the second electrode throughout the deflecton of the electron beam across the display screen. By virtue thereof, an improved picture reproduction can be obtained.

Abstract: A low voltage Einzel gun design maximizes the size of the second main lens to reduce spherical aberrations thereby reducing spot-size and improving focus quality. The gun's final accelerator electrode is formed as an internal conductive coating on the neck, which is connected to anode potential through an anode button. The jumper between the final and second accelerator electrodes is removed and the second accelerator electrode is connected through the high voltage stem pin to an external potential. Connection of the high voltage stem pin to anode potential defines an Einzel gun. The focus electrode is now connected to one of the low voltage stem pins. In a high voltage Einzel gun, connecting the second accelerator electrode and focus electrode to the high voltage and a low voltage stem pin, respectively, would cause arcing between the pins.

Abstract: A structure of an electron gun for a color cathode ray tube capable of reducing a drive voltage by creating an optimum relation among a cathode, a first electrode, and a second electrode mounted in the electron gun, and preventing degradation in response to input signals on a high-resolution screen and a focus characteristic.

Abstract: The invention relates to a cathode ray tube comprising means (5) for generating an electron beam (6,7,8), means (51) for deflecting the electron beam, and a coil (14′) for influencing a deflection of the electron beam (6,7,8). The coil (14′) comprises an electrically conductive coil holder (46) and coil windings (47,48) having an electrically conductive outer layer (44). The electrically conductive layer (44) of the coil wires (41) and the coil holder (46) cooperate with each other so as to form a conductive path A between successive coil windings (47,48). Due to the outer layer (44) of the wires and the conductive coil holder (46) an electrical path A between successive windings (47,48) is created that provides damping and by which ringing is suppressed.

Abstract: An electron gun assembly of a color cathode ray tube emits at least one electron beam having an oblong cross-sectional shape extending substantially in the horizontal direction, and emits three electron beams in a substantially non-convergent state toward the central portion of a phosphor screen. A deflection device comprises an auxiliary magnetic field generator for generating a quadrupole magnetic field component which focuses the electron beam with an oblong cross section more heavily in the horizontal direction than in the vertical direction. The auxiliary magnetic field generator is located in a given region in a tube-axis direction in which the horizontally deflecting coil is located.

Abstract: The present invention is to provide an electron gun of a monochromic CRT comprising at least two electron emission sources (e.g., cathodes) for emitting beams having a small beam spot size and being adapted to impinge on the same spot of a screen of the monochromic CRT after having been focused by a focusing lens or common lens in the electron gun. As an end, the resolution, focusing quality and brightness of the screen of the monochromic CRT are improved.

Abstract: An electron gun for a cathode ray tube includes at least one auxiliary quadruple lens forming unit adapted to control an electron beam diverging in the vertical direction and focused in the horizontal direction by a plurality of focus electrodes, at least one first quadruple lens forming unit adapted to control the electron beam passing through the auxiliary quadruple lens focused in the vertical direction and diverging in the horizontal direction, and at least one second quadruple forming unit adapted to control the electron beam passing through the first quadruple lens diverging in the vertical direction and focused in the horizontal direction, installed between the screen electrode of a triode portion and a final acceleration electrode of the cathode ray tube and sequentially arranged in a direction from a screen electrode to a screen of the cathode ray tube.

Abstract: The present invention provides a cathode ray tube which exhibits a favorable contrast by enhancing a speed modulation effect. A front-stage anode electrode and a focus electrode which constitute an electron gun are respectively divided into a plurality of portions. A plurality of portions of the divided front-stage anode electrode are arranged in the tube axis direction at given intervals and are electrically connected with each other. A plurality of portions of the divided focus electrode are arranged in the tube axis direction at given intervals and are electrically connected with each other. Due to gaps formed in the front-stage anode electrode and the focus electrode, the speed modulation effect is increased.

Abstract: Disclosed is a cathode ray tube with an electron gun capable of improving a resolution of an image by preventing electron beams from striking electrodes and efficiently controlling a spot size that is susceptible to a change in current capacity.

Abstract: A focusing electrode and a final accelerating electrode accommodate, respectively, a first and a second field forming electrode in positions set back from a first and a second aperture of their end faces opposed to each other. The first and the second field forming electrode have three electron beam passage apertures disposed in an in-line arrangement. When the in-line direction is an X-axis direction, a direction perpendicular to the in-line direction is a Y-axis direction and the center of a central electron beam passage aperture formed in the first field forming electrode is X=0 and Y=0, the central electron beam passage aperture has a shape that passes through the intersection points of the X-axis and the Y-axis with a curve represented by the equation (X/R1)2+(Y/R2)2=1 (where R1 and R2 are constants) and that has an area smaller than the area encircled by the curve.

Abstract: A deflection yoke of a cathode ray tube apparatus comprises a pair of saddle-type horizontal deflection coils located symmetrically with respect to a central axis and substantially in the shape of a truncated pyramid. A magnetic core substantially in the shape of a truncated cone is located coaxially around the horizontal deflection coils, and a pair of vertical deflection coils are wound on the magnetic core. A relation between a space vf between a large-diameter end portion of the magnetic core and each of the horizontal deflection coils and a space vr between a small-diameter end portion of the magnetic core and each of the horizontal deflection coils, with respect to the direction of a vertical axis perpendicular to the central axis, is given by vf≧vr.

Abstract: The present invention relates to a cathode ray tube, and more particularly, to a cathode ray tube with reduced stray emissions by improving the electrical conductivity of an electrode material of an electron gun housed in a funnel of the cathode ray tube.

Abstract: An electron gun for a color CRT includes a triode unit including a cathode, a control electrode, and a screen electrode for emitting an electron beam, first and second auxiliary focusing electrodes sequentially installed coaxially with the triode unit, for forming auxiliary lenses, first and second focusing electrodes installed coaxially with the first and second electrodes, for forming a quadrupole lens, and a final acceleration electrode installed close to the second focusing electrode, for forming a main lens. In the electron gun, protruding portions having flat surfaces corresponding to opposite surfaces of the first and second focusing electrodes are formed on at least one of the opposite surfaces of the first and second focusing electrodes to change the profile of the electron beam by applying a dynamic focus voltage to the edge of electron beam passing holes formed in the opposite surfaces.

Abstract: A color cathode-ray tube including an in-line electron gun and a color cathode-ray tube apparatus including the same are provided. At an end, on a screen side, of the electron gun, two pairs of members for generating a magnetic field are placed above and below side beams of three electron beams so as to sandwich them, respectively. Between each of the two pairs of members for generating a magnetic field, a localized barrel magnetic field is formed to vary cross-sectional shapes of the side beams positioned on both sides of a center beam so that the cross-sectional shape of one of the side beams is horizontally or vertically elongated to a higher degree than that to which the cross-sectional shape of the other of the side beams is. Magnetic fields for reverse correction of spot distortions of the side beams are generated and therefore the symmetry in the spot distortions of the side beams asymmetric with each other is improved, thus improving focus quality.

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 main lens section of an electron gun assembly comprises a fifth grid supplied with a focus voltage, a sixth grid supplied with a dynamic focus voltage, a first intermediate electrode, a second intermediate electrode, and a seventh grid. The main lens section includes an electric field lens acting commonly on the electron beams on a focus region side of the main lens section, which is formed by the fifth grid, sixth grid and first intermediate electrode, and a plurality of electric field lenses acting respectively on the electron beams on a divergence region side of the main lens section, which is formed by the second intermediate electrode and seventh grid.

Abstract: A multipole unit normally consists of a support tube, a threaded ring, a plurality of magnetic rings, a plurality of spacer rings and a spring ring. According to the present invention, the structural design of a multipole unit is simplified in that the threaded ring is modified in such a way that the spring ring becomes superfluous. In order to achieve this the threaded ring or a stop arranged on the support tube is provided with spring elements which fulfil the function of the conventional spring ring.

Abstract: The present invention provides an electron gun for a cathode ray tube that forms a main focus lens of a maximum diameter within a neck of a limited diameter to thereby realize high focus performance and resolution characteristics. The electron gun includes a single cathode emitting electrons; first and second grid electrodes forming a triode portion with the cathode; a third grid electrode provided subsequent to the second grid electrode; a fourth grid electrode provided subsequent to the third grid electrode and to which a focus voltage is applied, the fourth grid electrode including an input section positioned opposing the third grid electrode and an output section connected to the input section; a fifth grid electrode mounted surrounding part of the fourth grid electrode with a predetermined gap therebetween and to which an anode voltage is applied; and a connector interconnecting the third grid electrode and the fifth grid electrode, wherein the output section of the fourth grid electrode is exposed.

Abstract: An electron gun is provided for a CRT. The electrode gun includes three cathodes for emitting electron beams, a plurality of acceleration electrodes, and a focus electrode and an anode. The focus electrode and the anode each include an opposite rim having a single electron beam pass-through hole with a vertical width V and a horizontal width H, and an electrostatic field control body positioned at a distance D from the rim, with a bridge width ‘t’, and a vertical width v and a horizontal width h of a central electron beam pass-through hole, wherein the electrostatic field control body and the focus electrode and the anode are configured to satisfy the following equation: (VxvxD)/29≧H−(2×S), where, S denotes a sum of the horizontal width h and the bridge width t of the electrostatic field control body. Spherical aberration is prevented or reduced, improving a vertical resolution of the picture.

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 electron gun for a cathode ray tube includes a triode potion including cathodes, a first electrode, and a second electrode arranged with predetermined gaps therebetween. A plurality of electrodes arranged in sequence starting from a position adjacent to the second electrode. The electrodes receiving a voltage, for example, a constant voltage or a dynamic voltage. The dynamic voltage is synchronized with a deflection signal of electron beams. An anode electrode is positioned having a predetermined gap between the electrode arranged farthest from the cathodes. A support maintains the electrodes at predetermined intervals. One of the electrodes is a multiple-element electrode that includes two interconnected sub-electrodes. Gaps are formed between portions the sub-electrodes of the multiple-element electrode.

Abstract: An inline electron gun for use in a multi-beam electron gun as in a color cathode ray tube (CRT) includes a main focus lens for focusing the electron beams on the CRT's display screen for providing a video image. The main focus lens includes plural charged grids aligned in a spaced manner along the electron gun's longitudinal axis through which plural (typically three) electron beams are directed. One or more of these charged grids includes at least two aligned common apertures for passing the three electron beams. The layered common aperture arrangement allows for increasing the length of the electron gun as well as the effective diameter of the electron gun's main focus lens for improved video image resolution without introducing electron beam astigmatism.

Abstract: A CRT electron gun of the present invention has a cathode for emitting electrons toward a screen as a display face, a G2 electrode to which a voltage higher than that of the cathode is applied, a Gm electrode to which a predetermined voltage is applied, and a G3 electrode to which a voltage higher than that of the G2 electrode is applied, wherein at least those three electrodes are provided with an electron-passing opening and are arranged on the same axis in that order from the side of the cathode, and the potential of the aforementioned cathode is varied to vary the amount of electrons to be drawn; and in this, a configuration is made such that the lowest potential on the axis in a portion where the aforementioned Gm electrode exists substantially agrees with the maximum potential in a range where the potential of the aforementioned cathode varies, and a part of the electrons drawn from the aforementioned cathode flows into at least one of the aforementioned G2 electrode and the aforementioned Gm electrode.

Abstract: A cathode includes emitter tips provided on a substrate, a gate electrode with an electric field formed between the gate electrode and the emitter tips, and terminals and leads for supplying voltages to the emitter tips and the gate electrode, respectively. A shield electrode further is provided between the cathode and a control electrode, and the shield electrode has a cylindrical projecting portion projecting toward the cathode, through which electron beams pass. The disturbance of an electric field by the leads influences the electron beams; however, this can be prevented by the projecting portion. Because of this, even if the size of the cathode is reduced, the distortion of an electron beam spot on a phosphor screen can be reduced. As a result, a cathode-ray tube with high resolution can be provided at a low cost.

Abstract: A color cathode ray tube having an electron gun including an electron beam generating portion arrayed in a horizontal direction for generating three electron beams, and a main lens for focusing the three electron beams from the electron beam generating portion upon a fluorescent face. A final stage of the main lens is formed between a focusing electrode and an accelerating electrode. The focusing electrode is divided into at least two focusing electrode parts. A quadrupole electron lens is formed for each of the electron beams between a first focusing electrode part and a second focusing electrode part, and the strength of the quadrupole electron lens for the central electron beam is different from the strength of the quadrupole electron lens for the side electron beams.

Abstract: The electron beam generating section in an electron gun assembly includes a cathode having an electron emitting surface. The surface of the cathode is divided into at least three regions of first, second and third regions which have different electron emission capabilities. The first region is arranged in the center of the surface of the cathode. The second region has its portions arranged on opposite sides of the first region in the horizontal direction. The third region has its portions arranged on opposite sides of the first region in the vertical direction.