Abstract: A charged particle beam system can include a vacuum chamber, a specimen holder for holding a specimen within the vacuum chamber, and a charged particle column. The charged particle column can include a charged particle source for producing a beam of charged particles along an optical axis and a magnetic immersion lens for focusing the beam of charged particles. The magnetic immersion lens can include a first lens pole disposed adjacent a first surface of the specimen, an excitation coil surrounding the first lens pole, and a counterpole disposed adjacent a second surface of the specimen, the counterpole including one or more magnets disposed on the counterpole.

Abstract: The present invention has an object to provide a cold cathode field-emission electron gun with low aberration, to thereby provide a high-brightness electron gun even in the case of a large current. The present invention provides a field-emission electron gun which extracts an electron beam from a cathode and converges the extracted electron beam, the field-emission electron gun including: a magnetic field lens which is provided such that the cathode is disposed inside of a magnetic field of the lens; and an extraction electrode for extracting electrons from the cathode, the extraction electrode being formed into a cylindrical shape without an aperture structure. The present invention can provide an electron gun having a function of converging an electron beam using a magnetic field, the electron gun which is capable of reducing an incidental electrostatic lens action and has small aberration and high brightness.

Abstract: One embodiment relates to a high-voltage electron gun including an insulator stand-off having a resistive layer. The resistive layer is at least on an interior surface of the insulator stand-off. A cathode holder is coupled to one end of the insulator 115 stand-off, and an anode is coupled to the other end. The resistive layer advantageously increases the surface breakdown field strength for the insulator stand-off and so enables a compact design for the high-voltage electron gun. Other embodiments, aspects and feature are also disclosed.

Abstract: System that focuses electron beams in an electro-static area to a laminar flow of electrons with uniform distribution of current density and extraordinary demagnification includes a housing having a first interior portion and a second interior portion electrically insulated from the first interior portion. The second interior portion has an electric field-free space. An electrode system is disposed in the first interior portion and includes a cathode assembly and at least one anode assembly. The cathode assembly generates an electron beam that passes through each anode assembly and then into the electric field-free space in the second interior portion. A position of a crossover point on a longitudinal axis maybe regulated by varying dimensions of a substantially cylindrical portion of the anode assembly and a substantially cylindrical portion of a near-cathode electrode assembly.

Abstract: System that focuses electron beams in an electro-static area to a laminar flow of electrons with uniform distribution of current density and extraordinary demagnification includes a housing having a first interior portion and a second interior portion electrically insulated from the first interior portion. The second interior portion has an electric field-free space. An electrode system is disposed in the first interior portion and includes a cathode assembly and at least one anode assembly. The cathode assembly generates an electron beam that passes through each anode assembly and then into the electric field-free space in the second interior portion. The system parameters may be calculated and created due to the CGMR conceptual method.

Abstract: System that focuses electron beams in an electro-static area to a laminar flow of electrons with uniform distribution of current density and extraordinary demagnification includes a body that defines a boundary for an electric field, a field-forming cathode electrode system, a focusing electrode system, and at least one anode electrode system in the electro-static section and a second electric field-free section including an adjustable screen system arranged in an interior of the body. The field-forming near-cathode electrode system includes a cathode electrically connected to a flat part and a curvilinear part electrically connected to a cylindrical part. The anode electrode system includes an opening part, an anode electrically connected to a flat part and a curvilinear part electrically connected to a cylindrical part which is similar or identical to and symmetrical with the cathode electrode system. The system parameters are calculated and created due to the CGMR conceptual method.

Abstract: System that focuses electron beams in an electro-static area to a laminar flow of electrons with uniform distribution of current density and extraordinary demagnification includes a housing having a first interior portion and a second interior portion electrically insulated from the first interior portion. The second interior portion has an electric field-free space. An electrode system is disposed in the first interior portion and includes a cathode assembly and at least one anode assembly. The cathode assembly generates an electron beam that passes through each anode assembly and then into the electric field-free space in the second interior portion. The system parameters may be calculated and created due to the CGMR conceptual method.

Abstract: System that focuses electron beams in an electro-static area to a laminar flow of electrons with uniform distribution of current density and extraordinary demagnification includes a body that defines a boundary for an electric field, a field-forming cathode electrode system, a focusing electrode system, and at least one anode electrode system in the electro-static section and a second electric field-free section including an adjustable screen system arranged in an interior of the body. The field-forming near-cathode electrode system includes a cathode electrically connected to a flat part and a curvilinear part electrically connected to a cylindrical part. The anode electrode system includes an opening part, an anode electrically connected to a flat part and a curvilinear part electrically connected to a cylindrical part which is similar or identical to and symmetrical with the cathode electrode system. The system parameters are calculated and created due to the CGMR conceptual method.

Abstract: An electron beam apparatus of which the electron emission efficiency is high and in which capacitance between a gate and a cathode is small is provided. In the electron beam apparatus which is equipped with the gate and the cathode respectively formed on the side surface of an insulating member and an anode arranged on an elongation of a Z direction, the gate and the cathode are shifted from each other in a Y direction and then arranged so that orthogonal projection of the gate to the anode and orthogonal projection of the cathode to the anode do not overlap each other.

Abstract: A spacer, disposed between first and second substrates of an electron emission display, includes a main body, a resistive layer arranged on a side surface of the main body, a secondary electron emission preventing layer arranged on the resistive layer, and a diffusion preventing layer arranged between the resistive layer and the secondary electron emission layer. The diffusion preventing layer prevents interdiffusion between the resistive layer and the secondary electron emission preventing layer.

Abstract: A cathode structure of triode type which, superimposed over a substrate, includes a cathode electrode, an electric insulating layer, and a gate electrode, the electric insulating layer and the gate electrode having emission openings revealing at least one electron-emitting element electrically connected to the cathode electrode. The structure further includes a refocusing electrode arranged to refocus the electrons extracted by the gate electrode. The refocusing electrode is arranged on the electric insulating layer and is connected to an electric connection allowing a refocusing voltage to be applied to it via electrically conductive nanotubes. The cathode structure can be applied to a matrix-addressed field emission device.

Abstract: An electron gun for a cathode ray tube having a scanning velocity modulation coil mounted on an outer circumference of a neck of the cathode ray tube. The electron gun includes a cathode for emitting electron beams; a plurality of grid electrodes sequentially mounted starting from the cathode, and including a plurality of focus electrodes mounted with a predetermined gap therebetween; supports on which the grid electrodes are fixed in a row; and a shield electrode mounted between the focus electrodes and connected to the focus electrodes. The shield electrode defines a continuous space along an elongated axis direction of the cathode ray tube.

Abstract: A prefocus lens section is formed by a screen electrode and an additional electrode. A main lens section is formed by a focus electrode, an anode electrode and an intermediate electrode that is disposed between the focus electrode and the anode electrode. Each of the focus electrode and the intermediate electrode has a cylindrical electrode on at least one of opposed faces thereof. The intermediate electrode and the anode electrode have cylindrical electrodes on opposed faces thereof. A voltage with a level higher than a focus voltage and lower than an anode voltage is applied to the additional electrode and the intermediate electrode.

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 surface of a first grid electrode, which is located on a cathode side and is one of a plurality of electrodes for an electron gun used in an electrode gun assembly, is formed to be a rough surface having a higher degree of surface roughness than a surface of a second grid electrode located adjacent to the first grid electrode.

Abstract: An electron source includes a vacuum chamber within which a vacuum is maintained by a vacuum pump. An insulated receptacle is mounted within the vacuum chamber and has a receptacle mounting flange. The receptacle mounting flange is used to establish a coordinate system having an electron beam axis and a lateral plane, wherein the lateral plane is transverse to the electron beam axis. An adapter is mounted to the receptacle and is adjustable in five degrees of freedom with respect to the coordinate system. A cathode and focus electrode are adjustable in at least four degrees of freedom and are pre-aligned with respect to one another prior to being installed on the adapter. An anode is mounted in the vacuum chamber and is aligned at a predetermined distance from the cathode with respect to the coordinate system.

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: 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: An electron gun also has a cathode for emitting electrons, a heater cap which contains a heater for applying the cathode with thermal energy for emitting electrons, a retainer for securing the cathode on the heater cap by clamping the peripheral edge of the cathode onto the heater cap, and a cylindrical Wehnelt supporter. The cylindrical Wehnelt supporter has a Wehnelt electrode for focusing an electron beam that is formed in such a shape that an average angle of the surface thereof with respect to an outermost shell of the electron beam matches a Pierce angle, and three or more heater cap supporters for securely supporting the heater cap at a position at which an electron emitting surface of the cathode and an opening formed through the Wehnelt electrode satisfy a predetermined perveance.

Abstract: A cathode ray tube comprising an electron source and an electron beam guidance cavity having an input aperture and an output aperture, wherein at least a part of the wall of the electron beam guidance cavity near the output aperture comprises an insulating material having a secondary emission coefficient &dgr;1 for cooperation with the cathode. Furthermore, the cathode ray tube comprises a first electrode which is connectable to a first power supply for applying, in operation, an electric field with a first field strength E1 between the cathode and the output aperture. &dgr;1 and E1 have values which allow electron transport through the electron beam guidance cavity. The cathode ray tube further comprises a conventional main lens to obtain a spot on a display screen. According to the invention, an electron lens is placed between the exit of the cavity and the main lens for directing the electron beam at a predetermined angle towards the entrance of the main lens.

Abstract: A cathode-ray tube electron gun can alleviate unwanted radiation caused when cathodes and a first electron gun constitute an antenna by increasing the number of conduction leads of a first electrode of a cathode-ray tube electron gun from one to a plurality of conduction leads.

Abstract: An electron gun for a cathode ray tube is disclosed, which has a simple structure and can prevent the spot on a screen from being degraded. In the electron gun for a cathode ray tube including a cathode that emits electron beams, a first electrode that controls the electron beams emitted from the cathode, a second electrode that accelerates the electron beams emitted from the first electrode, and third to fifth electrodes sequentially arranged in a screen direction to act as pre-focus lenses, the electron gun is characterized in that the third to fifth electrodes have different sized electron beam through holes.

Abstract: A color cathode ray tube includes three in-line coplanar cathodes, a control electrode, an accelerating electrode, a focus electrode, and an anode. The control electrode is provided with three first-type electron beam apertures arranged in the in-line direction, each being elongated in the in-line direction. An end of the accelerating electrode facing the control electrode is provided with three through-hole electron beam apertures arranged in the in-line direction, each being superposed with a slit-shaped recess elongated in the in-line direction. An end of the focus electrode is provided with three non-axially-symmetric electron beam apertures arranged in the in-line direction, each having a major axis thereof in a direction perpendicular to the in-line direction.

Abstract: An electron gun for a color cathode ray tube including a triode consisting of a cathode, a control electrode and a screen electrode, and first and second focus electrodes facing each other and installed sequentially from the triode, for forming quadrupole lenses for focusing and accelerating an electron beam emitted from the triode, wherein three first-elongated electron beam passing holes slanting in one direction at a predetermined angle with respect to the longitudinal axis are formed on the facing surface of the first focus electrode, and three second-elongated electron beam passing holes slanting in a direction opposite to that of the first-elongated electron beam passing holes at a predetermined angle with respect to the longitudinal axis are formed on the facing surface of the second focus electrode, and wherein a dynamic focus voltage synchronized with a deflection signal is applied to the first focus electrode and a focus voltage is applied to the second focus electrode.

Abstract: A three in-line beam type color CRT includes a focus electrode and an anode. The focus electrode includes a first focus sub-electrode supplied with a first fixed focus voltage and a second focus sub-electrode supplied with a second fixed voltage superposed with a dynamic voltage synchronized with beam deflection, and the first and second focus sub-electrodes form a quadrupole lens therebetween. Two side electron beams are deflected toward a center electron beam with increasing dynamic voltage in the quadrupole lens. An axial distance Lgf (mm) from a cathode side end of the first focus sub-electrode to an anode side end of the second focus sub-electrode, an axial distance Ls (mm) from the end of the second focus sub-electrode to the phosphor screen, and a useful diagonal dimension D (mm) of the phosphor screen satisfy 0.06×Ls (mm)≦Lgf (mm)≦26 (mm) and 1.50≦D/Ls≦1.70.

Abstract: A trolling motor foot control for use with a trolling motor is disclosed. The trolling motor foot control includes a pad adapted to receive an operator's foot, a first operating interface coupled to the pad and adapted to be coupled to the trolling motor and a second operator interface coupled to the pad and adapted to be coupled to the trolling motor. The first operator interface is configured to adjust a speed of the trolling motor at a first rate in response to input from the operator's foot. The second operator interface is configured to adjust the speed of the trolling motor at a second smaller rate in response to input from the operator's foot.

Abstract: The invention relates to a method and a device for reducing an electric field produced by display devices equipped with cathode ray tubes, in their surroundings. According to the invention, a part of a spectrum (ff), caused by a picture content, the level of which is separately adjusted, is discriminated from an interference voltage frequency spectrum (fs), produced by the display terminal and caused by deflection signals (fv, fh). Spurious pulses, significant for the generation of the electric field, are connected to a compensation circuit, wherein they are summed and supplied to a common emitter. The directions of the pulses are determined so that the electric field produced by the emitter reverses the field produced by the display device.

Abstract: Since an internal surface of an arc ball receiving recess, which greatly affects the shape of an arc ball, is formed in an arcuate cross section swelling outward, the arc ball can be formed so as to be received in the arc ball receiving recess in front of a focusing opening of a slit shape, whereby the arc ball can be formed in a well-regulated form. Therefore, the arc ball with uniform luminance distribution in the longitudinal direction of the slit focusing opening can be made with certainty in the arc ball receiving recess.

Abstract: A Wehnelt electrode and a cold cathode are pressed against and fixed to each other under spring force with a ceramic plate interposed therebetween. Metallized layers connected to a gate electrode and a focusing electrode are disposed on surfaces of the ceramic plate. The gate electrode and the focusing electrode are connected to external power supplies via the metallized layers as feeder path structures. With this arrangement, an electron gun for an electron tube with a cold cathode can be designed with increased degree of freedom, reduced in size, can easily be assembled at the time of manufacture, has high dimensional accuracy, provides high dielectric strength between gate and Wehnelt electrodes, and is highly resistant to vibrations.

Abstract: Electron guns are disclosed that produce low-brightness and high-emittance electron beams that are suitable for use in an electron-beam reduction-lithography apparatus. A preferred embodiment comprises a cathode, a Wehnelt electrode, an anode, and at least one control electrode placed between the cathode and the anode. Each of these components defines a spherical surface all having a common center point and all thus being concentric with one another. During operation, the anode has a grounded electrical potential while the cathode and the Wehnelt electrode each have a potential of about -100 KV. If the applied voltage to the control electrode is adjusted within a range of -99 to -90 KV, the brightness can be controlled to within a range of 1.times.10.sup.3 to 2.times.10.sup.4 A/cm.sup.2.sr.

Abstract: An electron gun provides an improved focusing characteristic of electron beams surely and effectively, and permits position alignment to be relatively easy in assembling thereof. In an electron gun which includes a cathode for discharging electrons and a plurality of grids each having electron passing-through holes for guiding the electrons discharged from the cathode unidirectionally, an electron dischargeable region is formed in an electron discharging plane of the cathode, which is band-shaped. In addition, the length of the band-shaped area constituting the electron dischargeable region on its shorter side is less than 80% of the diameter of the area from where electrons are discharged when a practical maximum current is taken out without limiting the electron dischargeable region.

Abstract: An electron gun using a plane type cold cathode electrode has a beam focusing electrode which is disposed in front of the plane type cold cathode electrode and has a hole having a diameter smaller than an electron emission region. The beam focusing electrode is in direct contact with a cathode chip constituting the plane type cold cathode electrode, thus realizing direct electrical connection between the cold cathode chip and the beam focusing electrode. The arrangement enables the converging of an electron beam from the cold cathode electrode to a desired shape and the accurate setting of the center of a beam orbit to a desired position.

Abstract: A dynamic color separation display CRT having an electron beam forming structure for beam generation and electrostatic impingement control. The electron gun forms a group of electron beams and includes a multi-aperture G1 grid for receiving the electron beam group. The group of electron beams overlap and combine to provide an impingement pattern that matches a primary color stripe without use of a shadow mask when focused on the output screen surface. An alternate preferred embodiment includes a grooved cathode to control the size, shape, and profile of the emitted beam.

Abstract: A focussing lens for an electron beam device is formed by a helically coiled resistance layer of a fired suspension of a conductive material of a mixture of a lead rathenate, a lead titanate and a ruthenium oxide in a glass formed of silicon dioxide, aluminum oxide and lead oxide.

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 system for controlling the shape of a charged particle beam. The particle beam is emitted from a source (58) of the said particles. Said source is associated with a collecting electrode which collects the particles. The system comprises at least one resistive zone (56) and at least two control electrodes (52, 54). The resistive zone and the control electrodes are arranged substantially at the same level as the source. The control electrodes are also placed on either side of the resistive zone and serve to polarize the latter. The electrical resistance profile of the resistive zone is chosen in such a way that it has the potential distribution so that it is possible to obtain the desired shape of the beam from the source when the control electrodes are appropriately polarized.

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: A screen electrode of an electron gun is by uniting main electrode with an auxiliary electrode. The main electrode has three circular beam passing holes and a pair of guide holes for insertion in arbors of a jig disposed symmetrically around a center beam passing hole thereof. The auxiliary electrode has three elongated beam passing holes and a pair of guide slots for insertion in the arbors of the jig formed in a top edge and a bottom edge of the auxiliary electrode and coaxially positioned with the guide holes, thereby enabling easy centering of the main and auxiliary electrodes.

Abstract: The invention is directed to a high-voltage lead-through arrangement for introducing a high voltage into an enclosure wherein a vacuum is maintained such as for particle-beam apparatus. The arrangement includes: a high-voltage electrode for carrying a high potential; an insulator enclosing the high-voltage electrode and having a surface defining a boundary with the vacuum; and, an outer low-voltage electrode surrounding the insulator for carrying a low potential. The electrodes are spaced from each other by an electrode spacing measured along the surface of the insulator. The high-voltage electrode and the insulator conjointly define a first region wherein the high potential is present to a good approximation; and the first region is bounded by the insulator surface for a first distance of up to approximately 1/10 of the electrode spacing.

Abstract: A flat display includes a front panel having a fluorescent screen on its rear side, a rear panel defining a flat space with the front panel, linear filament cathodes arranged close to the rear panel, and an address electrode plate having a multiplicity of apertures and disposed close to the front panel. The rear panel is formed on its inner surface with spacer ridges each extending on each side of each filament cathode therealong and having a height to reach the address electrode plate. The spacer ridges give the flat display improved strength against pressure.

Abstract: A multi-step focusing type electron gun is disclosed which includes a cathode, electrodes G1 and G2, and electrodes G3, G4, G5, G6, G7, and G8 for forming two unipotential auxiliary lenses and a bipotential major lens in the main lens, characterized in that the electrodes G4, G5, G6, G7 are so constituted as to satisfy some specific formulas. The electron gun can reduce the size of the beam spot and the size of the halo formed around the beam spot. Further the electron gun improves the spherical aberration, and provides the flexibility in designing for different purposes, as well as improving the image quality on the screen.

Abstract: A flat configuration CRT has a plurality of line cathodes arrayed with a predetermined pitch, a focus electrode section for focusing respective electron beams which are emitted for the line cathodes, and pairs of deflection plates having opposed deflection electrodes for executing deflection of the focussed electron beams, the deflection electrodes of each deflection plate being divided into at least two parts, and an image display section upon which the electron beams are incident. The length of a region in which deflection is executed by the deflection electrodes is made no greaer than a value which is approximately three times the pitch of the line cathodes.

Abstract: An electron gun which is rugged, provides good thermal decoupling of the hode, permits precise alignment of the electrodes to be achieved easily and allows geometric changes to be carried out with ease is described. In the cathode assembly three set screws and a split ring of insulating material are used to secure the cathode. Alignment is achieved by suitably adjusting the set screws and because contact can be limited to the three set screws thermal coupling is reduced. Similarly a Whenelt electrode is secured and aligned by a further group of set screws. Finally, the anode is secured to replaceable stand-offs by means of screw passing through oversized holes in an anode plate. The oversized holes permit easy alignment and the use of stand-offs permits the spacing between anode and cathode to be changed as desired by replacing the stand-offs.

Abstract: A gun for generating a multiple sheet beams 50 of electrons has a flat surfaced cathode 10 with parallel protruding ridges 12 of non-emitting material forming parallel focus electrodes for the sheet beamlets. A control grid of parallel bars 14 is aligned with the ridges 12 to reduce grid interruption. The beamlets may be focussed between support bars 54 of a foil anode 52 for passing the beam into a high-pressure volume such as a gas laser 48. The ridges are formed by inserting non-emissive bent sheets into grooves 58 in the cathode, which are dovetailed to hold them.

Abstract: A camera tube system having an electron gun of the diode type. The electron gun is provided with an anode consisting of several parts. These parts are provided with apertures, are electrically separated and are adapted to be connected to means to control the potential. As a result of this, it is possible to generate a much larger beam current during the line flyback. This larger beam current makes it possible to avoid the so-called comet-tail effect.

Abstract: An electron beam device such as a cathode ray tube in which spherical aberration is reduced by optimising the axial potential distribution in the focusing lens of the electron gun. In one embodiment of the invention the electron gun comprises a beam forming part and a segmented focusing lens (25). The focusing lens (25) comprises a preformed glass tube (22) having a high-ohmic resistive layer (23) on the interior wall thereof, the resistive layer (23) comprises helical segments (33 to 37) alternated with intermediate segments (42 to 47). A focusing voltage is applied to the intermediate section (42) closest to the beam forming part and a higher voltage is applied to the end segment (47). The lengths of the helical segments (33 to 37) increase in a direction from the point of application of the focusing voltage whereas the lengths of the intermediate segments (42 to 46) decrease. The lengths of the helical segments (33 37) are such as to produce the desired axial potential distribution.

Abstract: Disclosed is a cathode cup for X-ray tubes which is manufactured in two pieces so that the filament can be set before the upper channels are added, thereby, simplifying accurate setting of the filament and minimizing the likelihood of causing scratches or nicks in the outer surface of the cup.

Abstract: An x-ray tube having an improved focusing arrangement is provided. The x-ray tube includes an evacuated envelope and an anode disposed within the envelope. A positive electrical potential, with respect to ground, is applied to the anode. A filamentary cathode emits an electron beam toward the anode. A first negative electrical potential, with respect to ground, is coupled to the filament and to an electrically conductive cathode body, which focuses the electron beam onto the anode at a focal spot, the focal spot having a length, corresponding to the length of the filament, and a width. The cathode body has an opening disposed therein and supports the filament in such opening. An electrode is insulatingly disposed in the opening of the body and applied with a negative electrical potential with respect to the first negative potential.

Abstract: An electron gun for a color picture tube has beam generators for generating three electron beams and directing them toward the fluorescent screen along three paths which are parallel with each other on the same plane, and at least one pair of electrode surfaces each having three apertures centered with the three paths for forming independent main lenses so as to focus the electron beams on the fluorescent screen, the electrode surfaces being spaced apart from each other. Provided for the electrode surface are cylindrical shield members centered with the apertures and extending from the apertures in opposition to the opposing electrode surface. Outer ones of the cylindrical shield members have each an end surface inclined with respect to the center axis of the aperture so as to form inclined electric fields effective to converge the outer beams to one point to which the central beam converges.

Abstract: An electron gun is disclosed which includes a thermionic cathode for emitting an electron beam, a grid having a first aperture for controlling the diameter of the electron beam, and an anode having a second aperture for catching a part of the electron beam having passed through the first aperture; and in which the diameter of the first aperture is smaller than or equal to the diameter of the second aperture, and the grid and the anode are applied with positive potentials relative to a cathode potential, for example, with a voltage of 5 to tens of volts and a voltage of 100 to 500 volts, respectively, to form a uniform axial field between the grid and the anode, thereby generating a laminar flow electron beam having a constant current density.