Abstract: An electron-optical display device includes a cathode ray tube having a cylindrical neck of very small external diameter, such as .ltoreq.15 mm, the inner surface of the neck having thereon a helical multi-element layer electrode formed of a high ohmic resistance material, which electrode constitutes a focusing lens. In combination with a deflection system of correspondingly small diameter and operating at high scanning frequencies, this makes it possible to use a very small scanning spot of high luminance and without requiring excessive deflection energy. The device may be used as a television image projection tube or as an electron beam pumped scanning laser.

Abstract: In an electron gun for a CRT in which a plurality of cylindrical electrodes are arranged and fixed in series to control a path of electron beams emitted from a cathode, a cylindrical support member is disposed between at least two adjacent cylindrical electrodes so that the two cylindrical electrodes are arranged coaxially. One end portion of the cylindrical support member and one cylindrical electrode are fixed to each other by fitting the former into the latter or vice versa, and the other end portion of the cylindrical support member and the other cylindrical electrode are fixed to each other by fitting the former into the latter or vice versa.

Abstract: In a color cathode ray tube apparatus including an electron gun assembly having a main electron lens section for focusing and converging three electron beams arranged in a line on a phosphor screen, three electron beam through holes arranged in a line in the arrangement direction of the three electron beams are formed in each of the opposing surfaces of the first electrode having a relatively low potential and a second electrode having a relatively high potential, which electrodes constitute the main electron lens and substantially oppose, the pair of side beam through holes of the second electrode are decentered outward in the arrangement direction of the three electron beams with respect to the pair of side beam through holes of the first electrode, and each of the pair of side beam through holes of any one of the first and second electrodes is formed to have a substantially horizontally elongated shape in which both sides in the arrangement direction of the three electron beams are constituted by arcs and

Abstract: In-line electron guns for color picture tube improving the resolution of the color picture tube. The guns not only exhibit the special quality of a large aperture of lens but also achieve the desired mechanical strength of electrodes by arranging .OR right.-shaped inner electrode plates in the envelope electrodes respectively. Each of first and second accelerating/focusing electrodes for focusing three electron beams of the electron beam sources on the phosphor screen includes an envelope electrode and an electrostatic field control electrode placed in the envelope electrode. The envelope electrode includes a predetermined length of hollow envelope part and a predetermined width of rim part extending from an edge of the hollow envelope part. The electrostatic field control electrode includes a plate electrode sided by predetermined width of blades at opposed sides thereof. This blade sided plate electrode is holed at its center so as to have a center beam passing opening.

Abstract: An electron gun for a color cathode-ray tube for providing a passage for a plurality of electron beams, each beam representing a color component for forming a color image. The electron gun of the present invention includes a pair of electrodes substantially symmetrical to one another with respect to the horizontal direction and coaxial with the tube in the axial direction. Each electrode has a common opening. Each common opening faces the other and is spaced from the other at a given distance in the axial direction. According to an embodiment of the present invention, each electrode includes first and second electrode member. The first electrode member inside the electrode is spaced at a given distance from the common opening of the electrode in the axial direction. The first electrode member includes a plurality of openings in cascade in the horizontal direction, and these openings partially overlap one another and communicate to one another collectively to form a singly aperture.

Abstract: A cathode ray tube comprising a cathode (K) for emitting a beam of electrons; a grid (G) for controlling the intensity of the beam; three or more anodes (A1, A3, A4); a control for varying the potential of at least one of the anodes (A3) for focusing the beam to form a spot on a screen; and an additional, dynamic focus electrode (A2) maintained generally at a potential close to the cathode/grid potential. Suitable structure may be included for applying to said dynamic focus electrode a high frequency signal to provide a rapid focus control. Said dynamic focus electrode may comprise a plurality of circumferentially disposed segments and including applying a separate high voltage to each segment thus allowing the possibility of creating a quadruple action in conjunction with at least one adjacent electrode, said segments covered with a deposited high-resistance conducting film to prevent charging effects.

Abstract: An inline electron gun for use in a multi-beam color cathode ray tube (CRT) has a main focus lens for focusing the electron beams on a display screen of the CRT. The main focus lens includes adjacent charged electrodes each having a respective common lens aperture through which the electron beams are directed and which are in facing relation for reducing horizontal spherical aberration of the electron beams on the display screen, where each common lens aperture has a longitudinal axis aligned with the inline electron beams. In one embodiment, each common lens aperture is chain-link-shaped including spaced, vertically enlarged portions, each aligned with a respective electron beam for correcting for vertical spherical aberration. Each adjacent electrode further includes a plurality of auxiliary apertures, each aligned with and passing a respective electron beam.

Abstract: An electron gun for a color CRT has three cathodes disposed in parallel to each other, first to fifth grid electrodes and a convergence deflector. The electron gun is additionally provided with a tetrode magnetic field generator including a pair of permanent magnets having an astigmatic effect of the central beam of the electron gun on the cathode side of the convergence deflector. An astigmatism eliminator is provided to cancel astigmatic aberration of the side beams of the electron gun near the position where the electron beams are converged. The astigmatism eliminator is composed of a fifth grid electrode whose entrance has an electron beam passing hole of nearly elliptic shape.

Abstract: Disclosed is a color cathode ray tube equipped with a main electronic lens section for focusing a plurality of in-line electron beams on a screen section. The main electronic lens section includes a plurality of grids each having electron-beam through holes and securely supported by a plurality of insulating supports. At least one of the grids has a rectangular cup portion with a substantially rectangular cross section for commonly enclosing the plurality of in-line electron beams and a face having electron-beam through holes formed at least at one end and substantially perpendicular to the rectangular cup portion. The ratio of an outside diameter L.sub.H of the substantially rectangular portion in a long-axial direction to an outside length L.sub.S thereof in a short-axial direction, L.sub.H /L.sub.S, is set to 2.5<L.sub.H /L.sub.S <4.4, and the ratio of the outside length L.sub.S to a diameter D.sub.V of the electron-beam through holes in the same short-axial direction, L.sub.S /D.sub.V, is set to 1.

Abstract: A color cathode ray tube (CRT) includes a multi-beam electron gun capable of operating in two or more modes for use as either a television receiver display or as a high resolution video monitor. The electron gun directs a plurality of electron beams onto the CRT's display screen, with the electron beams arranged in two or more groups. In one group of electron beams, the beam forming portion of the electron gun provides small diameter electron beams having reduced spot size on the CRT's display screen for high video image resolution when used as a monitor for graphics and/or character display. In another group of electron beams, the beam forming portion of the electron gun provides electron beams having a larger diameter and current for increased video image brightness when used as a television receiver. Each group of electron beams includes a plurality of horizontally aligned electron beams, with each beam providing one of the primary colors of red, green, or blue.

Abstract: An electron gun for the cathode-ray tube is disclosed, in which an early stage lens unit and a main lens unit are respectively constructed as a bipotential form lens. A high voltage equivalent to the voltage applied to a grid of the main lens unit is applied to a grid of the early stage lens unit thereby to reduce the space charge effect, while at the same time suppressing the change of the beam spot shape with the change in the beam current.

Abstract: A cathode ray tube has a gun electrode construction which elongates horizontally a cross section of an electron beam and whose elongating strength weakens as a focusing voltage increases.

Abstract: In an electron gun wherein an electric field which is established between the axially opposed parts of a pair of electrodes forming a main lens has a rotationally-asymmetric distribution; electric-field correcting plates (54, 65 in FIG. 1B) are provided in the respective electrodes (5, 6) so as to render a lens action on electron beams substantially rotationally symmetric. The electron beams form smaller spots on the fluorescent screen of a cathode-ray tube than in the prior art.

Abstract: An electrode structure of an electron gun for a cathode ray tube has a plurality of cathodes for emitting thermions, grid electrodes to form an electron beam of thermions, a first acceleration and focus electrode, a second acceleration and focus electrode and a dipole lens system which forms a circular beam spot on a screen of the cathode ray tube by removing the horizontal lengthening of the beam spot due to an increase in the amount of deflection of the beam in the peripheral portion of the screen of the cathode ray tube. The dipole lens system has a first electrode and a second electrode to which a dynamic voltage of a predetermined range is applied. The first electrode of the dipole lens system has opening portions which pierce the upper and lower sides of the first accelerator and focus electrode. The second electrode of the dipole lens system has horizontal plates which cover the opening portions with a predetermined gap.

Abstract: An electron gun for use in a color picture tube which can reduce the astigmatism of main electron lenses and to make small circular beam spots. The electron gun has three cathodes each injecting an electron beam respectively and main electron lenses which concentrate the three electron beams onto a fluorescent screen, wherein a third electrode and a fourth electrode consisting the main electron lenses are formed by two large apertured electrodes facing each other and two small apertured electrodes each having three apertures for correcting the astigmatism.

Abstract: In a color cathode ray tube apparatus including an electron gun assembly having a main electron lens section constituted by a plurality of electrodes for focusing three electron beams arranged in a line on a target and a deflection unit for deflecting the three electron beams, at least an electrode to which a voltage obtained by superposing a variable voltage changed in accordance with a deflection amount of the electron beams on a predetermined DC voltage and an electrode which substantially opposes the electrode and to which a voltage obtained by superposing a variable voltage induced through a capacitance between the opposing electrodes on a predetermined voltage applied through a resistor arranged in a tube is applied are arranged in a main electron lens section, and the main electron lens section is made into an electron lens for changing the focusing state of the electron beams in synchronism with deflection of the electron beams.

Abstract: A cathode ray tube having an electron gun for relatively low beam currents (less than 1 mA) is shown. The electron gun has a G1 and a G2 electrode. The voltage difference between these electrodes is more than 800 Volt and the electrical field strength E.sub.12 between said electrodes is more than 4 keV/mm. An improvement in spot size is thereby obtained.

Abstract: An electron gun for a color picture tube having heaters, cathodes, a control electrode, a screen electrode, a focusing electrode and a anode, the focusing electrode for forming a main lens and said anode further having elongated octagonally shaped apertures. The electron gun thus configured enables the convergence and resolution of the color picture tube to be improved.

Abstract: An improved color picture tube includes a screen and an inline gun for generating and directing three inline electron beams along separate paths toward the screen. The electron gun includes electrodes that provide a beam-forming region, a prefocus region and a main focus region. The beam-forming region of the gun includes a cathode, a G1 electrode, a G2 electrode and a first portion of a G3 electrode. The prefocus region includes a second portion of the G3 electrode, a G4 electrode and a first portion of a G5 electrode. The main focus region includes a second portion of the G5 electrode and a G6 electrode. The improvement resides in the beam-forming region, the prefocus region and the main focus region each being astigmatic.

Abstract: This invention relates to an electron gun for a color picture tube, comprising a focus electrode structure having three electron beam passage apertures including a center aperture of a circular shape and two side apertures each being of an oblong shape having a major axis extending transversely, being arranged such that the center-to-center distance between adjacent apertures of the three apertures is less than the center-to-center distance between adjacent apertures formed in a control electrode and a screen electrode. This focus electrode structure prevents deterioration of resolution of the picture tube due to changes of electron beam paths resulting from thermal deformation of the electrodes during operation of the gun.

Abstract: A cathode-ray tube has an electron gun sealed in a neck in confronting relationship to the phosphor screen. The electron gun comprises a cathode assembly for emitting three electron beams, a main lens region for passing the electron beams therethrough, the main lens means including a high-voltage electrode or grid closer to the phosphor screen, and an assembly of electrostatic deflection plates, positioned closer to the phosphor screen than the high-voltage electrode, for converging the electron beams as one spot on the phosphor screen. An electrostatic convergence electrode assembly is disposed between the high-voltage electrode and the deflection plates. The electrostatic convergence electrode assembly may comprise three or two juxtaposed flat electrodes having electron beam passage holes.

Abstract: An in-line type electron gun assembly has a cathode unit for producing a central electron beam and two side electron beams and first and second electrode units. Each of the first and second electrode units has a cylindrical member of a non-circular elongated cross section and a plate member provided on the inner wall of the cylindrical member so as to be joined therewith to define three electron beam passage holes juxtaposed, within the cylindrical member, in a direction parallel with a lengthwise direction of the elongated cross section of the cylindrical member. The plate member of each electrode unit has at least one hole therein serving as an electron beam passage hole for the central electron beam.

Abstract: An electron gun for use in a cathode ray tube (CRT) includes a cathode, a low voltage beam forming region (BFR), and a high voltage deflection focus lens disposed in the beam deflection region of the CRT's magnetic deflection yoke for simultaneous and coincident focusing and deflection of the electron beam on the CRT's display screen. The deflection lens includes a plurality of first focus grids disposed in the CRT's neck portion including a spaced first pair of grids each having respective beam passing apertures, with one of the beam passing apertures horizontally offset and the other beam passing aperture vertically offset from the electron beam axis. Other grids disposed on opposed sides of each of the first pair of grids have respective beam passing apertures centered with respect to the electron beam axis and are maintained at a fixed focus voltage.

Abstract: A pair of E-shaped shunts are disposed near the top and bottom, respectively, of a deflection yoke for reducing inner and outer horizontal trap errors. A central portion of the E-shaped shunt reduces a ratio between magnitudes of inner and outer E-W pincushion raster distortions.

Abstract: An electrode for electro gun of a cathode ray tube includes an external electrode member formed on the top of a cup-shaped body and having a large-diameter electron beam passing hole through which three electron beams pass commonly, and an internal electrode member inserted into the external electrode member and having three separate electron beam passing holes on the top of the internal electrode, wherein protrusions are formed on the outer surface of the internal electrode member, thereby enhancing the assembly precision of the external and internal electrode members.

Abstract: A dynamic focusing electron gun is provided which includes a cathode and first and second grids which collectively form a triode, a plurality of electrodes for forming an auxiliary lens, and an anode installed adjacent to the final electrode of the auxiliary lens for forming a main lens. Electron beam passing holes are formed in the electrodes of the auxiliary lens so that an electron beam is repeatedly and alternately deformed in the sequence of the vertically-elongated and then horizontally-elongated (or horizontally-elongated and then vertically-elongated) shapes, constituting more than two quadrupole lenses of opposing polarities.

Abstract: An electron beam for a color CRT is equipped with three cathodes such that three electron beams may be emitted therefrom. Three grids are provided with beam passing holes for each of the three electron beams and are positioned in the path of the electron beams. The beam passing openings of the third grid are shifted from alignment with the beam passing openings of the first and second grid by a degree sufficient to focus the three beams appropriately relative to a central focal axis of the electron gun.

Abstract: An electron gun for a cathode-ray tube has, in addition to its main lens, a triode with first and second grids as control electrodes. The thickness of the second grid, and the separation between the first and second grids, is at most one-half the diameter of the beam aperture in the second grid. These dimensions lead to formation of a prefocus lens with no concave lens component, hence with no beam diverging effect. The resulting triode aberration corrects spherical aberration in the main lens, so that the size of the beam spot focused on the screen has little tendency to increase with increasing beam current.

Abstract: An electron gun for a color cathode ray tube having sequentially formed a cathode, a control electrode, a screen electrode, a focus electrode and a final accelerating electrode, wherein the focus electrode is constituted by first and second focus electrodes. The first focus electrode includes an evenly formed electron beam inlet plane and an electron beam outlet plane in which a portion for shaping a central electron beam passing hole is formed convexly in respect to portions for shaping outer electron beam passing holes, while the second focus electrode comprises an evenly formed electron beam outlet plane and an electron beam inlet plane in which a portion for shaping a central electron beam passing hole is formed concavely in respect to portions for shaping outer electron beam passing holes. The quadruple lens formed between outer electron beam passing holes is formed asymmetrically, to improve the convergence characteristic.

Abstract: An electron gun such as used in a cathode ray tube (CRT) includes an Einzel lens having charged G3, G4 and G5 grids for focusing an electron beam on the CRT's display screen. The G3, G4 and G5 grids are cylindrical and have the same inner diameter, with their respective longitudinal axes colinear and aligned with the electron beam axis. Where T is the thickness of a grid and L is the G3-G4 or G4-G5 spacing, or gap, shielding against stray electrostatic fields within the grids arising from stray electrons on either a grid-supporting glass bead or on the inner surface of the CRT's neck portion is provided by maintaining the relationship 3.0.gtoreq.T/L.gtoreq.0.75. Another embodiment employs thinner grids having a thickness t with outward turned end flanges, or folded edges, disposed about facing edges of adjacent grids having a thickness T, where T>t and the above-stated relationship of T/L is maintained.

Abstract: An electron gun for a color cathode ray tube includes a cathode, control and screen electrodes forming a triode, 1st to 3rd focus electrodes forming a first unipotential prefocus lens, 4th and 5th focus electrodes forming a second unipotential prefocus lens with the 3rd focus electrode, a 6th focus electrode forming a bipotential prefocus lens with the 5th electrode adjacent thereto, and an accelerating electrode for forming a bipotential main focus lens with the 6th focus electrode. Vertically-elongated electron beam passing holes are respectively formed in the outgoing planes of the 1st, 3rd and 5th electrodes and horizontally-elongated electron beam passing holes are respectively formed in the incoming planes of the 3rd, 5th and 6th focus electrodes.

Abstract: Disclosure relates to a cathode ray tube formed in the neck portion of a funnel, which comprises an electron gun including a cathode, a control electrode and a screen electrode constituting a triode, and a magnetic substance formed between the cathode and the control electrode to focus the electron beam on the control electrode, so that the electron beam emitted from the cathode ray tube is focused toward an electron beam passing hole of the control electrode to improve the focussing characteristics and current density of the electron beam.

Abstract: In an electron gun for a cathode-ray tube according to this invention, a quadrupole lens having a small spherical aberration and an asymmetrical lens are combined to properly focus an electron beam, thereby greatly reducing the size of a beam spot formed on a target on a screen.

Abstract: An electron gun for a color cathode ray tube includes a last accelerating electrode having a large-caliber electron beam passing hole for commonly passing red, blue, and green electron beams. Both ends of the beam passing hole include circular arc portions formed with a predetermined curvature. The center portions where the green electron beam passes through protrude by a predetermined width. The length of the protrusion in the horizontal direction satisfies the following inequality: L<H-2R(1+cos .alpha.), where H designates the horizontal width of the large-caliber electron beam passing hole, R is the radius of the circular arc portions and .alpha. is the angle between a line drawn from either center of the circular arc portions to an adjacent apex of the protrusions and a line connecting centers of both circular arc portions.

Abstract: A cathode-ray tube has an electron gun disposed in its neck in confronting relationship to a phosphor screen through a deflection yoke mounted on the funnel. The electron gun has a cathode assembly for emitting three electron beams, and a main lens for passing the electron beams therethrough. The main lens includes a quadruple lens system responsive to focusing voltages for canceling an astigmatic effect produced on the electron beams when the electron beams are deflected by the deflection yoke, at a peripheral edge of the phosphor screen.

Abstract: In an inline electron gun for use in a color cathode ray tube (CRT), a fixed, or static, electrostatic quadrupole in the low voltage beam forming region (BFR) exerts a negative astigmatism on the electron beams in reducing beam horizontal cross-section and compensating for the horizontal under-focusing of the beams by the CRT's self-converging magnetic deflection yoke. The negative astigmatism is compensated for by a dynamic electrostatic quadrupole in the CRT's main focusing lens. The electrostatic quadrupole in the CRT's BFR includes either a plurality of spaced, horizontally oriented, aligned, elongated indentations in the G.sub.2 facing surface of the G.sub.1 control grid or a plurality of spaced, vertically oriented, elongated indentations in the G.sub.1 facing surface of the G.sub.2 screen grid, where each of the indentations has an associated through-hole circular aperture through the grid.

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 to generate a main lens field and a quadrupole field. During operation, the intensity of the fields is dynamically varied. The electron gun comprises a prefocusing lens portion having means of generating a prefocusing lens field and a further quadrupole field. During operation, the intensity of said fields is controlled so that a dynamic cylindrical lens is formed in the prefocusing lens portion. By virtue thereof, an improved picture reproduction can be obtained.

Abstract: There is disclosed a cathode-ray tube which employs an electron gun assembly of the laminar flow (LF) type. The beam emanating from the LF electron gun assembly is directed through a three-electrode einzel lens assembly where the center electrode of the einzel lens assembly is subjected to a modulation voltage. Positioned after the einzel lens assembly are magnetic deflection circuits which include a horizontal and vertical coil enabling the beam to deflect in the horizontal and vertical directions and which circuits are positioned internally within the CRT. A convergence assembly is also built within the neck of the CRT. Thus, the CRT provides the advantages of the laminar flow gun while enabling modulation of the electron beam to provide an extremely small spot size to enable the CRT to operate with small spot size and to provide more efficient deflection at higher modulation rates.

Abstract: An electron gun for a color cathode ray tube includes a cathode, a control electrode and a screen electrode constituting a prepositioned triode. First, second, third and fourth focus electrodes form two pre-focus lenses and a final accelerating electrode positioned adjacent to the fourth focus electrode forms a main focus lens. The first pre-focus lens is synchronous with a deflection signal. Variation of the focussing intensity of the main focus lens is compensated for by the first pre-focus lens.

Abstract: A Pierce electron gun is provided having a cathode, a focusing electrode surrounding the cathode, and an anode disposed a fixed distance from the cathode and having an opening therethrough. The electron gun has at least one grading electrode disposed between the focusing electrode and the anode. The grading electrode controls shape of equipotential lines of an electric potential difference provided between the anode and the cathode, to purposely reduce field gradient levels formed by the electric potential difference. The grading electrode further has a double radial bend having an inner radial curve of a first radius and an outer radial curve of a second radius.

Abstract: An electron gun for a cathode ray tube (CRT) includes a cathode, a low voltage beam forming region (BFR), and a high voltage deflection focus lens disposed in the beam deflection region of the CRT's yoke for simultaneous focusing and deflection of the electron beam on the CRT's display screen. The deflection lens includes a first electrode either in the form of a cylindrical metal grid or a conductive coating disposed on the inner surface of the CRT's neck portion and extending into the magnetic deflection field. The deflection lens further includes a second electrode disposed either on or immediately adjacent to the inner surface of the CRT's frusto-conical funnel portion intermediate the magnetic deflection yoke and the CRT's display screen.

Abstract: An improved cathode-ray tube includes a viewing screen and an electron gun for generating and directing three electron beams toward the screen. The gun includes at least eight electrodes spaced in order from three cathodes, with the furthest electrode from the cathodes being interconnected to a tube anode. The electrodes form a beam forming region, a first quadrupole lens, a main focus lens and a second quadrupole lens in the path of each electron beam. In the improvement, the second quadrupole lens is positioned on the anode side of main focus lens, with the first quadrupole lens being diverging for defocusing the beams, and the second quadrupole lens being converging for focusing the beams in the horizontal plane.

Abstract: An electron gun for a cathode ray tube includes common large-aperture electron beam passing holes which are formed by recessing the portion except the rims on the outgoing side plane of a focus electrode and the incoming side plane of a final accelerating electrode, for expanding an electric field. Three independent small-aperture electron beam passing holes are formed at the recessed position by a predetermined depth from the rims. The ratio of the horizontal diameter to the vertical diameter of the central electron beam passing hole among the three independent small-aperture electron beam passing holes of the focus electrode is smaller than those of the outer independent small-aperture electron beam passing holes. Accordingly, the influence of the spherical aberration to the electron beam which passes through the main lens is reduced, so that the quality of the picture reproduced on the screen is improved.

Abstract: An electron gun for a color cathode ray tube is formed such that parallel vertical blades are extending toward cathodes formed at both edges of each electron beam passing hole in the outgoing plate of a focus electrode. Horizontal blades extending toward the cathodes at a predetermined length are formed at the edges of the top and bottom portions of electron beam passing holes in the incoming plate of a dynamic focus electrode. Thus, the horizontal blades are inserted into the electron beam passing holes of the focus electrode, which reduces astigmatism due to deflection aberration and improves the focusing characteristics.

Abstract: An inline type electron gun has a lopsided electric field applied to it to improve the spot formation of an electron beam in forming an expanded focus lens. The electron gun has first electrode to eighth electrode and has a lopsided electric field formed only at the two side apertures of a trio of apertures formed at one of the opposing sides of the sixth and seventh electrodes before a lopsided main focus lens formed between the seventh and eighth electrodes.

Abstract: In a multi-focusing type electron gun in which first through eighth electrodes and a shield cup are provided, the sixth electrode which forms the center of a second unipotential lens is formed by a primary electrode and a corresponding secondary electrode. The center aperture of the primary electrode has a larger inside diameter than lateral apertures thereof, which is equal to the inside diameter of the lateral apertures of the secondary electrode. The center aperture of the secondary electrode has a comparatively smaller inside diameter than the lateral apertures thereof but which is equal to the inside diameter of the lateral apertures of the primary electrode, so that a voltage difference of the second unipotential lens becomes uniform to obtain an expanded focus lens.

Abstract: An improved resolution electron gun for a cathode ray tube(CRT) is provided having a cathode, a control grid and an anode. A positive voltage is applied to the anode for the purpose of drawing the electron beam from the cathod, which emits the electron beam along its principal axis. The control grid between the cathode and the anode has a modulating drive voltage to modulate the emitted beam. The anode and the grid are aligned along the principal axis of the cathode and are adjacent to one another. A limiting aperture is mounted along the principal axis to clip the beam and reduce its diameter. A screen is provided along the principal axis within the CRT to receive the projected beam. To obtain increased resolution, the modulating drive voltage is increased while the aperture size is decreased. More specifically, the modulating drive voltage is increased beyond 25% of a predetermined maximum cutoff value, and the limiting aperture permits less than 50% of beam current to transmit.

Abstract: A one-gun three-beam electron gun comprises a triode part controlling an electron source generating a plurality of electron beams and emission of the electron beams generated by the electron source; a main electron lens of bi-potential focusing type consisting of not less than two cylindrical electrodes focusing the plurality of electron beams emitted by the triode part; electrostatic deflection plates disposed on the screen side of the main electron lens; and electrostatic deflection plates disposed on the electron source side of the main electron lens.

Abstract: An electron gun for a color cathode ray tube includes cathodes, a control electrode and a screen electrode which form a front triode, first, second, third, fourth and fifth focus electrodes which form a plurality of auxiliary electrostatic lenses, and a final accelerating electrode installed adjacent to the fifth focus electrode to form a main electrostatic lens, wherein vertically-elongated electron beam passing holes are formed on the fourth focus electrode, a predetermined focus voltage is applied to the first, second and fifth focus electrodes, a dynamic focus voltage lower than the focus voltage and synchronized with a deflection synchronizing signal is applied to the fourth focus electrode, a static voltage higher than the focus voltage is applied to the second focus electrode, and an anode voltage higher than the focus voltage is applied to the final accelerating electrode.

Abstract: An electron gun for a cathode ray tube is formed such that the spacing between the electron beam passing holes in a static focus electrode is longer than that between the electron beam passing holes in a dynamic focus electrode which forms a dynamic quadrupole lens with the static focus electrode, thereby enhancing the focusing and convergence characteristics of electron beams.