Abstract: An indirectly heated cathode structure for use in cathode ray tubes containing a hollow sleeve of cylindrical shape wherein one edge portion of the sleeve is folded outwardly and backwardly around and against the sleeve. A cap having a circular surface surrounded by a circular sidewall is disposed over the folded edge portion of the sleeve. The sidewall contains an annularly shaped ledge extending around an interior surface portion thereof upon which an end of the folded edge portion of the sleeve rests so as to increase the resistance of the cap to push-off forces applied thereto when the sleeve is restrained. A method for forming the foregoing structure is also disclosed.

Abstract: An indirectly heated cathode including a conductive cup having a closed end provided with an exterior surface coating of electron emissive material and an electrically insulated heater element disposed axially within the cup. The heater element comprises a coaxial pair of outer and inner filamentary coils wound helically in electrical series from a single strand of electrical wire and having integral interconnecting portions adjacent the closed end of the cup for resiliently supporting the inner coil within the outer coil and in alignment with the central portion of the electron emissive coating.

Abstract: A semiconductor cathode is provided with deflection electrodes, with which a dipole field can be generated. As a result of this, electrons released at the surface of the semiconductor cathode leave the surface at a certain angle. For use inter alia in camera tubes, display tubes, such an inclined beam can be aligned without any problems. Positive ions which are released inter alia from residual gases and are accelerated in the direction of the cathode impinge on the cathode at an acute angle. As a result of this, the active part of the cathode is substantially not attacked by said positive ions, so that degradation is prevented.

Abstract: A cathode-ray tube having an electron gun includes a novel cathode sleeve, a heater filament having a heater body with a pair of heater legs disposed within the sleeve and a pair of heater straps attached to the heater legs. The novel cathode sleeve comprises a generally longitudinally extending first portion having a first diameter which conforms closely to the heater body portion of the heater filament for reducing the power requirement thereof, and a second generally longitudinally extending portion having a diameter greater than the first diameter. The second portion has a segment which coaxially encompasses a section of the first portion of the cathode sleeve. The segment of the second portion is connected to the section of the first portion by a reverse drawn transition region which effectively extends the thermal length of the cathode sleeve to minimize the conduction of heat therealong.

Abstract: A cathode-ray tube having an electron gun includes at least one cathode assembly comprising a novel cathode sleeve, a heater filament disposed within the sleeve and a cathode eyelet disposed around at least a portion of the cathode sleeve and attached thereto. The cathode sleeve has oppositely disposed ends, one end being open and the other end being closed by a cap having an electron emitting coating thereon. The novel cathode sleeve comprises a longitudinally extending first portion having a first diameter conforming closely to the heater body portion of the heater filament for reducing the power requirement thereof, and at least one other longitudinally extending portion having a diameter greater than the first diameter. The first portion and the other portion of the cathode sleeve being connected by a transition region inclined at an obtuse angle to the longitudinally extending first portion of the sleeve.

Abstract: In a cathode-ray tube an inline electron gun assembly includes a center cathode assembly disposed between two outer cathode assemblies. The center cathode assembly and the outer cathode assemblies each comprise a tubular cathode sleeve having oppositely disposed ends, a filament disposed within the sleeve and spaced therefrom, and a cathode eyelet coaxially surrounding at least a portion of the cathode sleeve. The cathode sleeve is open at one end and closed at the other end by a cap having an electron emissive material thereon. The open end of the cathode sleeve is attached to the interior surface of the eyelet. At least a portion of the interior surface of at least one of the eyelets is modified to change the radiant energy emission characteristics thereof.

Abstract: By providing the cathode, in a diode electron gun in a television camera tube, with an at least 40 .mu.m high collar extending in the direction of the anode, the anode current is considerably reduced.

Abstract: A cathode-ray tube, such as a camera tube or a display tube, having an electron gun with a cathode unit including a cathode shank (30) suspended coaxially in an aperture in an assembly plate (38) and extending perpendicularly to the longitudinal axis of the electron gun. The cathode unit includes a metal supporting plate (41) which is accurately positioned with respect to the assembly plate (38). The assembly plate (38) and the supporting plate (41) each have two apertures through which supporting pins (44) for electrical connection lugs (32) extend. Glass plugs (43) connect the assembly plate (38), the supporting pins (44) and the supporting plate (41) together.

Abstract: A cathode filament formed from a thin metal wire wound into a helical spiral is welded at its two ends to connection braces by means of a high energy beam such as a laser beam. By increasing the pitch of at least one of the turns near each of the two ends, welding is confined to a predefined number of turns and uniformly welded cathodes are obtained having filament resistances which differ by less than 1%.

Abstract: A cathode-ray tube having an electron gun includes at least one cathode assembly comprising a tubular cathode sleeve, a heater filament disposed within the sleeve and a novel cathode eyelet coaxially surrounding at least a portion of the cathode sleeve and attached thereto. The cathode sleeve has oppositely disposed ends, one end being open and the other end being closed by a cap having an electron emitting coating thereon. The novel eyelet comprises a laminated bimetal member including a support layer and an emissivity modifying layer. The support layer has a distal end, a proximal end and a central portion therebetween. The proximal end of the support layer is attached to the open end of the cathode sleeve. The emissivity modifying layer is disposed on at least a portion of the interior surface of the central portion of the support layer to reduce radiation loss from the cathode sleeve and cap.

Abstract: An improved broad beam electron gun having a hot cathode assembly which is comprised of cathode means for generating a substantially hemispherical space-charge distribution, the cathode means including electron emitting structures having principal electron emissive surfaces which lie in hypothetical cylindrical-shaped surfaces, the axes of revolution of which are coincident with the major axis of symmetry of the electron emitting structure, the major axis of symmetry being orthogonal to the plane of the anode, the electron emitting structures variously including concave filament sections which form a tip, cylinders and coils, and wherein an electron beam of broad, uniform cross-sectional area is obtained without a shaping grid.

Abstract: The invention relates to disc-like metallic means for supporting the cathode assembly in a miniaturized cathode ray tube single electron gun structure. Its substantially planar construction with radially extending supporting leg elements incorporates shapings which achieve both compactness and ruggedness. The beneficial strengthening effects are provided by the integration of a rim on the disc portion with U-shaped cross-sectional shapings of the leg elements.

Abstract: A field emission electron gun (10) is disclosed which has an extraction electrode, composed of one or more sharply pointed electrode tips (17) in close proximity to a field emission cathode tip (11), such that a relatively low voltage between the cathode tip (11) and the extraction electrode tips (17), in the range of 100 to 2000 volts, will cause field emission of electrons from the cathode tip due to the extremely high localized electric field at the cathode tip. The electrons in the beam extracted from the cathode (11) are at a relatively low kinetic energy, particularly adapting the beam for use in such applications as low energy electron microscopy and low energy electron diffraction. For such applications, the extracted beam is generally passed through a limiting aperture member (21), electrostatic lenses (24, 25), and a deflection coil (26) when scanning of the target (27) is desired.

Abstract: Critical spacings between the cathode and grid of an electron gun structure are enabled by a cathode structure including a removable spacer, such structure produced by first forming a layer of potentially electron emissive material on the cathode, then forming a solvent drop on the layer, and contacting the drop with a spacer to adhere the spacer to the layer.

Abstract: An electron gun for generating an electron beam, comprising a cathode unit composed of at least a cylindrical cathode shaft having an end surface which forms an emissive surface. The cathode shaft is surrounded at least partly by a cylindrical metal heat reflection screen which extends beyond the open end of the cathode shaft. The cathode shaft and the heat reflection screen are secured in a cathode support, wherein the cathode shaft is suspended in the heat reflection screen so as to be self-supporting by means of metal strips or wires which are secured to the cathode shaft near the emissive surface and to the cathode support. This arrangement increases thermal efficiency and decreases warm-up time.

Abstract: A quick operating type cathode having a cathode body consisting of: a cathode sleeve and a metal substrate which is mounted at the top opening part of the cathode sleeve and the top surface of which is coated with an electron-emissive material; and a double helical coil heater which is inserted within the cathode sleeve and the surface of which is coated with an insulating material, is characterized in that said heater comprises a coil part and a pair of leg parts connected to the end part of said coil part, a dense pitch part is formed at the top of said coil part, a sparse pitch part is formed in said coil part at the side of the leg parts and the amount of said coated insulating material per unit length of the coil wire at said sparse pitch part is larger than that at said dense pitch part.

Abstract: A cathode assembly for cathode-ray tube which comprises a cathode sleeve with a blackened surface, a first cylindrical reflective member fixedly put on the top end portion of the cathode sleeve with a fixing point therebetween and having one end portion closed up with a metal substrate, and a second cylindrical reflective member attached to the cathode sleeve by means of support members so as to be on the same axis with the cathode sleeve and having a diameter greater than that of the cathode sleeve, both the first and second cylindrical reflective members being provided for reflecting radiant heat from the cathode sleeve, and the length of the first cylindrical reflective member being set so that an angle formed between the longitudinal direction of the cathode sleeve and a straight line connecting a heat radiation peak point on the outer surface of the cathode sleeve and the inner edge of a top opening portion of the second cylindrical reflective member, on a plane passing through the same axis, may be 30.

Abstract: A cathode eyelet has its cathode receiving end formed in an elliptical cross-section. Pressure on the long axis opens the short axis to a dimension large enough to admit the cathode. Removal of the pressure allows the sides of the ellipse defined by the short axis to collapse and frictionally retain the cathode in position until it is welded to the eyelet.

Abstract: Disclosed is a directly heated cathode assembly for a cathode ray tube electron gun, comprisingfirst and second conductive support members disposed to face each other via an insulating base plate,a ribbon filament stretched between the first and second conductive support members such that the width direction thereof is parallel with the axis of the electron gun,a cathode consisting of a metal substrate covered with an electron emissive coating and a support portion integral with or fixed to the metal substrate, the coating layer extending in a direction perpendicular to the axis of the electron gun and the cathode being mounted to the central portion of the filament, andat least one spring member whose free end resiliently abuts against the filament in a direction perpendicular to a plane including the axis of the electron gun.

Abstract: The invention relates to a semiconductor cathode based on avalanche breakdown in the p-n junction. The released electrons obtain extra accelerating energy by means of an electrode provided on the device. The achieved efficiency increase makes the manufacture of such cathodes in planar silicon technology sensible. Such cathodes are applied, for example, in cathode ray tube, flat displays, pick-up tubes and electron lithography.

Abstract: A flat panel display device having a plurality of electron propagation channels utilizes a line cathode. The cathode extends across all the channels and modulation electrodes associated with the channels cause the cathode to emit the electrons into the spaces between parallel guide meshes within the propagation channels. The cathode and modulation electrodes are arranged in a recessed cavity in the proximity of launch electrodes so that the electrons are emitted at high velocity into the propagation channels to travel curved paths along which the electron beams are converged into the spaces between the guide meshes. Electron propagation structure within the channels, therefore, is displaced from the cathode so that the cathode heat has a substantially reduced effect on the propagation structure, and the high electron velocity minimizes the effect of mechanical tolerances on the electron beam.

Abstract: An electron gun structure which includes at least one cathode electrode, a plurality of grid electrodes including a first grid electrode, and a heater coil. The cathode electrode consists of a tubular cathode sleeve and an electron emissive coating formed on the closed end of it. The heater coil is positioned within the cathode sleeve and has legs welded to the heater supporting straps. The surfaces of the heater straps adjacent cathode sleeve are constructed such that the arcing start potential between the cathode electrode and the heater supporting straps is lower than the arcing start potential between the cathode electrode and the heater coil, thereby preventing arcing to the heater itself.

Abstract: Presented is a cathode-heater assembly including a support structure for the cathode-heater assembly that is particularly rugged in that it resists displacement of the cathode-heater assembly in all planes, and minimizes power requirements to raise the cathode to operating temperature.

Abstract: An electron discharge device including an evacuated envelope having therein an indirectly heated cathode comprised of a metallic cathode cup having a cylindrical wall provided with an outwardly extended pair of opposing axially sloped flanges which contactingly engage respective opposing bevelled surfaces of a dielectric support ring encircling the wall and having an inner periphery radially spaced therefrom.

Abstract: A large cathode structure having a diameter on the order of 50 cm for producing uniform plasmas in a magnetic field. The cathode is oxide-coated and indirectly heated by a plurality of heater wires disposed in insulating tubes arranged parallel to each other. The cathode is pressed against the insulating tubes thereby to maintain it substantially flat in spite of expansion and contraction due to the heating and cooling effects. Optionally, the insulating tubes carrying the heater wires may be backed up by a second set of insulating tubes disposed at right angles to the first set. An annular ring is disposed about the cathode and is provided with tungsten springs for forcing the cathode against the heater tubes. This ring may additionally serve as a heat shield and maintain the temperature more uniform about the periphery of the cathode. For large cathodes, the structure may be water cooled by the provision of two copper tubes through which the water flows.

Abstract: An electron gun structure which includes at least one cathode electrode, a plurality of grid electrodes including a first grid electrode, and a heater coil. The cathode electrode consists of a tubular cathode sleeve and an electron emissive coating formed on the closed end of it. The heater coil is positioned within the cathode sleeve and has legs welded to heater supporting straps. The surfaces of the heater straps adjacent the cathode sleeve are constructed such that the arcing start potential between the cathode electrode and the heater supporting straps is lower than the arcing start potential between the cathode electrode and the heater coil, thereby preventing arcing to the heater itself.

Abstract: An electron beam tube having a cold cathode capable of being used as a caa tube or a display tube. The tube is constructed of two sections which are fitted together in a vacuum. The first section includes the tube neck and face section and an annular opening having a taper at the end thereof. The second section houses the cold cathode and a surface contact area for abuttably engaging a resilient electrical connector housed in the first section. The second section is forceably fitted over the taper on the first section to effect a vacuum tight seal.

Abstract: Improved means are provided for supporting a thermionic cathode in a cathode ray tube electron gun structure. A dual-leg configurated wire component, evidencing minimal mass and low heat sink characteristics, is utilized to provide positive support for the cathode and promote rapid cathode warmup.

Abstract: Cathode cup has a stop shoulder therein. Cathode is spring urged against the stop shoulder so that it is retained in position through mechanical shock and thermal cycling. The method of assembling the cathode structure includes the step of compressing the spring loaded structure and staking the cathode cup behind the spring.

Abstract: An electron beam producing arrangement for a cathode ray tube comprises a vessel-shaped control electrode with an opening in its end wall for the passage of the electron beam, two substantially rectangular insulating washers abutting a cylindrical inner wall of the control electrode with opposite sides and the end wall of the control electrode with third sides, the third sides having notches thereon and a straight line cathode wire supported in the notches substantially parallel to the end wall and below the opening therein.

Abstract: The cathode electrode assembly of an electron gun assembly comprises an inner cathode cylinder supporting a base metal coated with an electron emitting material and an outer cathode cylinder coaxially supporting said inner cathode cylinder. Said outer cathode cylinder is supported at a first supporting point by a cathode holder fitted over said outer cathode cylinder. Said cathode holder is supported at a second supporting point by an electrode supporting piece supported by an insulating support pillar. Respective portions of the outer cathode cylinder and cathode holder are formed of the same quality of material.

Abstract: The invention concerns an electron gun for the production of an electron beam designed primarily for welding workpieces and including, in a frame, the mechanical facilities required for holding in a coaxial position and electrically insulating a cathode, a filament, a wehnelt and an anode.Gun featured by the fact that the cathode is held by mechanical systems in the coaxial position via several rods made of conductive material, one end of these rods being rigidly fixed with respect to the frame, the other end being applied against the outer wall of the disc shaped cathode, thus forming a positioning clamp for said cathode.The structure allows for the efficient cooling of the internal parts of the gun.

Abstract: A thermionic cathode structure includes a ceramic base plate, a heater layer of tungsten coated on the ceramic base plate, a cathode lead layer of tungsten formed on a ceramic insulating layer covering the heater layer, a base metal layer coated on the cathode lead layer, and a cathode material coated on the base metal layer.

Abstract: A face-plate of an image pick-up tube having a plurality of electrodes formed thereon and a plurality of conductors provided for external connection extending from said plurality of electrodes across the outer periphery of the face plate to the outer surface thereof. At least one of the plurality of conductors for said external connection comprises a thin film which is electrically insolated from the other conductors by a thin insulating film formed thereon. This thin insulating film also serves to seal, in an air tight manner, a vacuum envelope together with the conductor or conductors for external connection extending to the outer surface of the face-plate.

Abstract: An electron gun system is described for generating a high current collimated beam of electrons for use in a shaped beam cathode ray tube system. The electron gun includes a cathode having an electron emitting surface for generating free electrons, a collimating grid axially spaced from the cathode and having a central aperture, and a control grid axially spaced from the collimating grid and having a central aperture axially aligned with the aperture of the collimating grid. The control grid receives a varying potential for establishing an electric field which is substantially axial over at least a central portion of the electron beam so as to collimate the beam axially.

Abstract: An electron gun cathode for a cathode ray tube in which the cathode has a fast warm-up characteristic to produce a visible raster within about 6 seconds. The emissively-coated cathode cap is of reduced mass, with the cathode heater coil disposed within the cathode cap having a high weight to length ratio, and with a darkened coating thereon to increase the emissivity therefrom.

Abstract: A device for generating a high level electron current pulse includes a housing whose interior can be evacuated from outside the housing, a cathode electrode located in the housing and arranged to be connected to a high voltage generator, an anode electrode disposed in the housing in facing relation to the cathode electrode, the anode electrode having an opening aligned with the electron emission portion of the cathode electrode and being provided with a grid which covers this opening and which presents a high electron transmission level, the grid defining a plane with one face of the anode electrode, and the walls of the housing defining an annular space filled with a solution whose resistivity is a function of its concentration to give these walls a variable electrical resistance which can be adjusted to match the impedance of the cathode electrode - anode electrode system to that of the high voltage generator.

Abstract: Device comprises an evacuated envelope and a heater-cathode assembly including an electrically-conductive, porous metal body containing electron-emission material and at least two electrically-resistive legs attached directly to spaced positions on the body. Electric current flowing through the legs and body generates heat in the legs, which heat is thermally conducted to the body. The parts are proportioned to reduce radiation losses by minimizing surface area. The structure reduces bulk and mass to permit short heating-up times.

Abstract: An electron beam generator with a linear cathode which has at least one end clamped to enable the cathode to move longitudinally. A beam forming electrode is at the same potential as the cathode and has an exit opening for the electron beam. The beam-forming electrode is provided with connection means to supply beam and heater voltage to the cathode. The clamps used to clamp the cathode, are connection contacts for the ends of the cathode and are outside of the contact points in the emission area of the cathode.

Abstract: An improvement is provided in a plural beam cathode ray tube electron gun assembly wherein positive positioning and embedment of the heater support means is achieved. One of a plurality of heater support means is oriented in each of a plurality of longitudinal rods supporting the gun assembly, in the area intervening between the embedded termini of two adjacently positioned cathode assembly support means positioned in side-by-side relationship. During gun assembly fabrication, localized movement of the softened glass of the rod, is restricted between the termini thereby effecting improved embedment of the heater support therebetween.

Abstract: An improvement in the means for supporting individually shielded cathodes is provided in a plural beam cathode ray tube electron generating assembly incorporating an in-line electron gun arrangement integrated by four spaced-apart longitudinal insulative rod-like supporting members. Each of the individual all-metal cathode assemblies is separately supported in a spatial manner apart from the related cup-like control electrode wherein a portion of the respective cathode assembly is oriented. The three cathode positioning members have discretely formed extremital portions embedded in the longitudinal supporting member to provide improved shielding and enhanced structural end-support for the in-line gun assembly.

Abstract: A grid-controlled electron source comprises an apertured grid spaced in front of a thermionic cathode. Areas of the cathode directly behind the grid conductors are made non-emissive by a bonded surface layer of non-emissive material such as zirconium. On porous metal cathodes impregnated with active emitting material the metal surface may be sealed with a dense layer of inactive metal under the non-emissive layer to prevent chemical reaction of the latter with the emitting material.Methods of depositing the surface layers in the desired pattern include coating the cathode's entire large-scale surface contour, followed by machining small concave dimples into the surface, thereby removing the non-emissive layer from the dimpled surfaces from which small beamlets of electrons are focused between the grid conductors without grid interception.Another method is to mask the desired non-emissive areas with an apertured mask having solid elements registered with the desired positions of the grid conductors.

Abstract: A method and apparatus for preventing oscillations in high-current electron guns. Spurious oscillations frequently occur as a result of interaction of the electron stream with the fields of resonant modes of the gun structure. The resonant impedances of the modes are lowered by damping with lossy dielectric or resistive materials which are suited to the high temperature and vacuum environment of electron guns. The lossy materials are located in places shielded from high electric fields applied to the gun. Lossy dielectric materials which are D.C. insulators may be used as insulating supports for gun electrodes.