Abstract: An electron gun for a monochrome cathode ray tube to be used in a projection display device includes a cathode for emitting thermal electrons, and first and second electrodes forming a triode portion together with the cathode. A third electrode is adjacent the second electrode. A fourth electrode is adjacent the third electrode to receive a focus voltage. A fifth electrode partially surrounds the fourth electrode while being adjacent the fourth electrode to receive an anode voltage together with the third electrode. The second electrode has a bottom portion with a stepped portion surrounding a hole for guiding the electron beams while being protruded toward the first electrode, and a sidewall portion extended from the periphery of the bottom portion toward the third electrode. The first and the second electrodes are structured to satisfy the following condition: 0.54?T/G?1.

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: Correction of electron beam landing misalignment in a raster-type display is undertaken without using the usual set of coils, but rather by superimposing a landing misalignment correction signal on the already-existing velocity modulation (VM) coil or on another coil located at the junction of the electron beams in the neck of the display. The correction signal may be varied based on pressure, temperature, and ambient magnetic field as indicated by respective sensors to appropriately correct electron beam landing on phosphors the positions of which may be affected by variations in magnetic fields, temperature, and pressure.

Abstract: Axially symmetric magnetic fields are provided about the longitudinal axis of each beam of a multi-beam electron beam device. The magnetic field symmetry is independent of beam voltage, beam current and applied magnetic field strength. A flux equalizer assembly is disposed between the cathodes and the anodes and near the cathodes of a multi-beam electron beam device. The assembly includes a ferromagnetic flux plate completely contained within the magnetic focusing circuit of the device. The flux plate includes apertures for each beam of the multi-beam device. A flux equalization gap or gaps are disposed in the flux plate to provide a perturbation in the magnetic field in the flux plate which counters the asymmetry induced by the off-axis position of the beam. The gaps may be implemented in a number of ways all of which have the effect of producing a locally continuously varying reluctance that locally counters the magnetic field asymmetry.

Abstract: At least one of the electrodes of an electron gun assembly is constructed by coupling at least first and second electrode members arranged in a direction of passing of electron beams. The first electrode member has a projecting portion on an end face thereof, which is to be coupled to the second electrode member disposed adjacent to the first electrode member. The first electrode member is coupled to the second electrode member via the projecting portion.

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: 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: An electron gun for a color cathode ray tube includes a cathode which is a source for emitting an electron beam, a control electrode, through which the electron beam emitted from the cathode passes, having first electron beam passing holes each including a first vertically elongated indented portion formed at an output side surface of the control electrode and a first electron beam passing hole portion formed in the first indented portion, a screen electrode installed adjacent to the control electrode and having second electron beam passing holes formed in the screen electrode, a plurality of focusing electrodes for forming a plurality of quadrupole lenses, sequentially installed from the screen electrode and respectively having electron beam passing holes having a predetermined shape.

Abstract: An electron gun includes a first focusing electrode and a second focusing electrode that are disposed so as to face each other and supplied with equal electric potentials. An electron beam passing aperture provided in at least one of a surface of the first focusing electrode facing the second focusing electrode and a surface of the second focusing electrode facing the first focusing electrode is a single opening common to three electron beams. Much of the magnetic flux from a scanning velocity modulation coil provided on outer peripheral surface of a neck portion of a funnel crosses this single opening. Thus, the scanning velocity modulation (SVM) sensitivity improves.

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: 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: Color CRTs, used in large display screens, have a plurality of three color electron beams that are strongly focused so that they crossover and become divergent in both the X and Y axes of the CRT's face. The strength of the focusing determines the size of the illuminated area on the face of the CRT. A shadow mask, aperture grill, or slotted mask and the red, green and blue phosphor dots or stripes are located at predetermined positions such that the red electron beams only hit the red phosphors, the green electron beams only hit the green phosphors, and the blue electron beams only hit the blue phosphors. No raster scanning with the electron beams are required.

Abstract: An electron gun includes plural aligned charged grids each having an aperture (in a monochrome CRT) or plural apertures (in a color CRT) through which an electron beam (or beams) is directed. The beams emitted by a cathode sequentially transit a beam forming region (BFR), a dynamic focus lens and a main focus lens prior to being incident on the CRT's display screen. The electron beam tends to expand in diameter in the direction of the CRT's display screen. This results in an increase in the focusing effect on the electron beam of the electron gun's grids in proceeding from the BFR toward the display screen where the beam passing apertures in the various grids are of the same size. To increase electron beam focusing sensitivity while reducing the beam's dynamic focus voltage, the beam passing apertures in the gun's dynamic focus lens are provided with progressively reduced size in proceeding toward the electron gun's cathode.

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: The method of assembling an electron gun for a cathode-ray tube comprises the steps loading of at least two electrodes (20, 70) one above the other, adjusting the distance between the electrodes along the longitudinal axis of the gun, and loading the electrodes between the two jaws (30, 30′, 31, 31′, 60, 60′, 61, 61′) of a positioning tool (35). The further includes positioning of the electrodes in the plane perpendicular to the longitudinal axis by clamping the jaws of the tool in a single direction, until a pressure is exerted on four corners (23) of each electrode and retaining by hot insertion of glass beads (40) into claws arranged on the periphery of the electrode openings of the positioning tool. The tool holds the electrodes in planes perpendicular to the longitudinal axis of the gun.

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: 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: An electron gun for a CRT includes a pair of bead glasses separated from and parallel to each other, supporting electrodes of the electron gun. An electrode has electron beam passing holes and at least one electrode support embedded in each bead glass. The electrode support includes at least two embedding protrusions embedded in the bead glass. One of the protrusions is longer than the other protrusion. The structure of the electrode support is improved so cracks in a bead glass during a beading process do not occur and twisting in a gap between the bead glass and an electrode support is minimized. There is no gap between the bead glass and the electrode, so leakage current does not flow between the electrodes, improving the lifetime of electrical features of the electron gun.

Abstract: A color image display device has an auxiliary means for compensating brightness simply and inexpensively by using an electron gun of a cathode ray tube. Brightness uniformity is improved in the image display device having a flat-type color cathode ray tube with a glass panel having a high wedge ratio and a low transmissibility. The color image display includes a panel housing a screen on an inner face thereof, a funnel engaged with the panel; an electron gun engaged with a neck portion of the funnel for emitting electron beams toward the screen, a deflection device for displaying an image by deflecting the electron beams emitted from the electron gun in horizontal and vertical directions with respect to the screen, and a cathode ray tube including a shadow mask aligned from the screen at a predetermined distance.

Abstract: An electron gun for a cathode ray tube includes a single cathode that emits thermions; first and second electrodes; a plurality of focus electrodes provided consecutively after the second electrode; an anode electrode mounted after a final focus electrode; and a support that supports the electrodes in an aligned configuration. The final focus electrode and the anode electrode are mounted opposing one another with a predetermined gap therebetween. If a lengthwise direction of phosphor layers forming a phosphor screen of the cathode ray tube is a Y axis direction, and a direction perpendicular to the Y axis direction is an X axis direction, an electron beam aperture formed in a portion of the final focus electrode opposing the anode electrode, and an electron beam aperture formed in the anode electrode have diameters in the X axis direction that are larger than corresponding diameters of electron beam apertures formed in the remaining electrodes.

Abstract: Among a plurality of electrodes composing an electron gun, at least one electrode is separated into two along a plane substantially perpendicular to a central axis, the two being a first cylindrical electrode and a second cylindrical electrode. Between the two electrodes, a connecting member in an approximate cylindrical shape having a slit is interposed, which electrically connects the first and second cylindrical electrodes with each other. The first and second cylindrical electrodes are fixed to a support rod via the connecting member and support portions provided on a side of the connecting member. Since a modulation magnetic field from outside a cathode-ray tube passes through the slit, eddy current loss can be reduced, whereby a desired electron beam modulation effect can be achieved.

Abstract: A cathode ray tube includes a bulb including a front panel and a funnel, and an electron gun. The front panel includes a color selection mechanism and phosphors on an inner surface thereof. The funnel includes a conductive layer on an inner wall thereof. The electron gun is accommodated in a neck portion of the funnel. The conductive layer is divided into at least two regions, each of which has a different electric potential. A high electric potential conductive layer having a high electric potential, an insulating region, a resistive layer, and a low electric potential conductive layer having an electric potential lower than that of the high electric potential conductive layer are formed in this order from the panel side to the electron gun side. With this configuration, the two conductive layers do not interfere with each other because of discharge or the like and are independent, and stable voltage can be maintained. Thus, an electrostatic lens can be formed.

Abstract: Disclosed is an electron gun for a cathode ray tube capable of improving substantial resolution by improving the alignment of a triode portion. The electron gun includes a triode portion composed of at least one cathode for emitting electron beams, and a first electrode and a second electrode for controlling emission amount of the electron beams, a focus electrode and an anode electrode forming a prime lens for focusing the electron beams on a screen, and at least two guide holes housed in more than two electrodes for use of assembly besides electron beam passage holes, in which at least one guide hole is circular and at least one of the other guide holes is non-circular.

Abstract: An inline electron gun and a color cathode ray tube provided with the inline electron gun for reducing the manufacturing cost for an assembly jig of the electron gun, for example, that might be generated with a change in the size of the cathode ray tube and for realizing a favorable static convergence property is provided. The inline gun includes a first flat plate electrode, a second flat plate electrode, two cylindrical electrodes at least is used. An opening geometry of outer passage holes provided in the first flat plate electrode and the second flat plate electrode is configured by combining an inner curve and an outer curve, which have different degrees. The opening geometries of the outer passage holes are symmetric with respect to a line. At least one of the outer curves and the inner curves in the outer passage holes have different degrees.

Abstract: A cathode ray tube with a reduced beam spot size on a fluorescent screen is obtained by forming electron beam passing holes on the electrodes composing a triode portion of an electron gun to have horizontally and vertically asymmetric shapes.

Abstract: A cathode ray tube (CRT) has an electron gun including a cathode for emitting electron beams, a control electrode for controlling emission of the electron beams from the cathode, and a screen electrode for accelerating the flow of the electron beams passing the control electrode are arranged in series. In the CRT, during a scanning period, a voltage applied to at least one of the control electrode and the screen electrode changes in response to a voltage of a data signal applied to the cathode. The control electrode and screen electrode each include three mutually electrically insulated sections for independently controlling each of three electron beams passing through the electrodes.

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: An electron gun for a color cathode ray tube efficiently modulates magnetic field of a velocity modulation coil. The electron gun contains at least two focus electrodes receiving a fixed focus voltage, and the focus electrodes are arranged in a row in the electron gun. When a sum of lengths of the focus electrodes is ‘L’ and a sum of intervals of the electrodes is ‘g’, the relationship (g×100)/L=5-30(%) is satisfied.

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: Cathode ray tube having an electron gun which is modified with respect to the electron gun having three equidistant cathodes lying “in line”. The cathode for generating the green (central) beam is offset with respect to its position in an in-line gun, and the grids in the focus and/or triode part of the gun have been modified to provide at least one kink in the trajectory of the green beam to restore convergence.

Abstract: A cathode ray tube has an anode and a focus electrode. The large-diameter cylinder portion of the focus electrode is disposed concentrically within a large-diameter cylinder portion of the anode. The anode and a first electrode facing a cathode side end of the focus electrode are electrically connected together within the cathode ray tube. The following relationship is satisfied: −LP+184.9≧LG4≧0.0004 LP3−0.1571 LP2+21.006 LP−922.41, where LG4 (mm) is an axial length of the focus electrode, and LP (mm) is a distance from a phosphor screen side end of the focus electrode to a center of a phosphor screen.

Abstract: In a cathode ray tube equipped with an electron gun for radiating multiple electron beams each scanning different positions, it is made possible to modulate velocities of the electron beams individually.

Abstract: A color cathode ray tube having at least an electron gun, constituted by a cathode for forming a plurality of electron beams arranged in-line, and a focusing electrode and an anode constituting a main lens for focusing and accelerating the electron beams and a fluorescent screen. The focusing electrode includes at least a first division electrode and a second division electrode arranged with a gap for controlling a scanning speed of the electron beams in common. The second division electrode is opposed to the anode and has, in an opposed surface thereof, a single opening for passing the plurality of electron beams in common. A length of the first division electrode in the axial direction of the tube is longer than a length of the second division electrode in the axial direction of the tube.

Abstract: In an electron gun assembly, its main convergence lens is composed of a focus electrode to which a focus voltage is applied, an anode electrode to which a high anode voltage is applied, and an intermediate electrode which is provided between the focus and anode electrodes and to which a high intermediate potential higher than the focus voltage and lower than the anode voltage is applied. The anode and intermediate electrodes are each a cylindrical unit long in the in-line direction. In the direction crossing at right angles with the in-line direction of the cylindrical units, the diameter of the opening in the anode electrode is set smaller than that of the opening in the intermediate electrode, thereby forming a multiple pole lens into a main electron lens of large aperture.

Abstract: An electron gun for a monochrome cathode ray tube to be used in a projection display device includes a cathode for emitting thermal electrons, and first and second electrodes forming a triode portion together with the cathode. A third electrode is adjacent the second electrode. A fourth electrode is adjacent the third electrode to receive a focus voltage. A fifth electrode partially surrounds the fourth electrode while being adjacent the fourth electrode to receive an anode voltage together with the third electrode. The second electrode has a bottom portion with a stepped portion surrounding a hole for guiding the electron beams while being protruded toward the first electrode, and a sidewall portion extended from the periphery of the bottom portion toward the third electrode. The first and the second electrodes are structured to satisfy the following condition: 0.54≦T/G≦1.

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 a flat cathode-ray tube, there are problems that an axis of electron beam is separated before the electron beam enters a main lens due to magnetic field of a magnet disposed outside a neck, and coma aberration is generated to degrade an image quality. It is an object of the present invention to solve these problems. A flat cathode-ray tube comprises an electron gun 281 having a main lens 35M whose center coincides with a tube axis, a deflection yoke, and a magnet disposed outside a neck. An axis of a prefocus lens of the electron gun is separated from the tube axis.

Abstract: A dynamic focus electrode has a vibration-damping portion formed by a beading process at a peripheral portion of an electron beam passage hole thereof, a plate face thereof, or an embedment portion thereof. Thereby, vibration of the dynamic focus electrode is suppressed.

Abstract: A video imaging apparatus comprises first and second cathode-ray tubes, each having an ultor electrode and a focus electrode. A power supply generates an ultor voltage, which may have a fluctuating voltage component produced by beam current variations, and which is coupled to first and second ultor electrodes of the first and second cathode-ray tubes. A high voltage amplifier generates a dynamic focus voltage component at a frequency related to a deflection frequency. A combining network combines the fluctuating voltage component and the dynamic focus voltage component to develop a combined, dynamic focus voltage. The combined, dynamic focus voltage is coupled to each of the first and second focus electrodes for developing from the combined, dynamic focus voltage each of a first dynamic focus voltage at the first focus electrode and a second dynamic focus voltage at the second focus electrode.

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: 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 provides a high-resolution color picture tube device with a decreased beam spot diameter. The color picture tube device has an electron gun including cathodes, a control electrode, an accelerating electrode, a G3 electrode, a first focusing electrode, a second focusing electrode, and a final accelerating electrode that are arranged in this order. A voltage applied to the G3 electrode is obtained by dividing with a resistor a voltage applied to the final accelerating electrode, and when an electron beam is a non-deflection state, a relationship represented as Va>Vg3>Vfoc2 is satisfied where Va, Vg3, and Vfoc2 denote voltages respectively applied to the final accelerating electrode, the G3 electrode and the second focusing electrode. Thereby, the G3 electrode is applied with a high voltage independently for forming a prefocus lens.

Abstract: The present invention relates generally to an electron gun for a color cathode ray tube, and more particularly to an electron gun for achieving an excellent focus characteristic on the whole screen by forming a dynamic quadruple lens in the electron gun used for a transpose scan type cathode ray tube.

Abstract: An electron gun as for a cathode ray tube includes a plurality of electrodes biased at different potentials to electrostatically shape and focus the one or more electron beams produced thereby. A dynamic focus grid is driven by a substantial ac voltage signal at the horizontal line rate, which signal is undesirably coupled through parasitic capacitance to an intermediate grid located between the dynamic focus grid and the gun anode. A resistive biasing network includes a high value resistance to divide the anode potential to develop bias potential for the intermediate grid and a capacitance to ac couple the intermediate grid to ground potential. The resistance is formed in a single layer ceramic circuit and the capacitance is formed on the single layer ceramic circuit or on the tube neck. The ceramic circuit may be located in the tube neck on or with the electron gun.

Abstract: There is provided an electron gun for a cathode-ray tube, comprising a triode having a control electrode and an accelerating electrode for controlling the amount of electron beams emitted from a plurality of cathodes and accelerating the electron beams, a front focusing lens part configured of a plurality of electrodes focusing and accelerating a predetermined amount of the electron beams, and a main lens part configured of a plurality of electrodes for focusing the electron beams on a screen, in which the diameter of beam passage hole of the accelerating electrode of the triode corresponds to 140-220% of that of the control electrode. The thickness of the control electrode corresponds to 20-30% of the diameter of beam passage hole of the control electrode, and the distance between the control electrode and the accelerating electrode corresponds to 40-80% of the beam passage hole diameter of the control 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: An electron gun for a color cathode ray tube including an electron beam generating unit for generating three electron beams arranged in-line horizontally, an auxiliary lens forming unit for forming an auxiliary lens for focusing and accelerating the electron beams generated by the electron beam generating unit, and a main lens forming unit for forming a main lens, for finally focusing and accelerating the electron beams focused and accelerated by the auxiliary lens forming unit, and having first and second outer electrodes which face each other and in each of which a large electron beam aperture through which the three electron beams pass is located, and first and second inner electrodes respectively located inside the first and second outer electrodes and having three electron beam apertures with vertically elongated rectangular shapes.