Abstract: A cathode assembly (27) includes a thermally conductive insulating substrate (21) having a pair of opposing surfaces. A cathode base member (24) is formed on one surface of the insulating substrate, and a heating member (25) for heating the cathode base member is formed on the other surface of the insulating substrate. A heater electrode terminal (26) is fixed to the electrode of the heating member through a metal layer (26a). A first grid (30) is fixed to the insulating substrate to oppose the cathode base member through a predetermined space.

Abstract: A cathode-ray tube is provided with an electron gun having a cathode and a control electrode and some other electrodes. The cathode includes an electron emissive material layer for emission of electrons through a hole in the control electrode. The hole in the control electrode has a diameter substantially in a rage of from 0.3 mm to 0.4 mm. The electron emissive material layer has a first layer made of an oxide of an alkaline earth metal formed on a support and containing no oxide of a rare earth metal, and a second layer made of an oxide of an alkaline earth metal formed on the first layer and containing an oxide of a rare earth metal substantially in an amount of from 0.8 wt % to 5.0 wt %.

Abstract: An electron tube cathode comprises a base (1) formed mainly of nickel, an alloy layer (4) disposed on the base (1) and including nickel and tungsten having a grain size smaller than that of the base, and an electron emissive material layer (5) deposited on the alloy layer, and including an oxide (6) of an alkaline-earth metal containing at least barium, and a rare earth metal oxide (7) of 0.01 to 25 weight percent and containing at least one of scandium oxide and yttrium oxide. The cathode has a life characteristics improved compared with the prior art, even if operated with a current density of 3 A/cm.sup.2 or more.

Abstract: A cathode for an electron tube including a base body having nickel as a major component and including at least one kind of reducing agents, a metal member in a layer-like shape, which has as a major component a metal provided with a reducing power equivalent to or smaller than a reducing power of the at least one kind of reducing agents included in the base body and larger than a reducing power of nickel and which is formed on faces of the base body, an electron emitting substance layer formed by depositing alkaline earth metal oxides including barium on the metal member, wherein the metal member is formed on the faces of the base body such that the base body is restrained from deforming by thermal stresses of intermetallic compounds formed at portions of the base body bounded with the metal member.

Abstract: The present invention discloses a cathode for an electron gun comprising a base metal mainly composed of nickel and containing one kind of reducing element at least, a metal layer mainly composed of tungsten, tungsten-nickel, or zirconium-tungsten on the upper side of the base metal, and an electron emitting material layer containing alkaline earth metal oxide including barium at least on the upper side of the metal layer. The metal layer is formed by spreading tungsten, tungsten-nickel, or zirconium-tungsten on the base metal and heating it to have particle smaller than that of the base metal, to increase its life cycle under a high current density load by ensuring a diffusion route of reducing element steadily, used for good generation of free radical barium atom.

Abstract: A field emission cathode is provided comprising an emissive member formed of a porous foam carbon material. The emissive member has an emissive surface defining a multiplicity of emissive edges.

Abstract: There is provided an impregnated-type cathode substrate comprising a large particle diameter low porosity region and a small particle diameter high porosity region which is provided in a side of an electron emission surface of the large particle diameter low porosity region and has an average particle diameter smaller than an average particle diameter of the large particle diameter low pore region and a porosity higher than a porosity of the large particle diameter low porosity region, the impregnated-type cathode being impregnated with an electron emission substance.

Abstract: A method for fabricating a field emission device (200) includes the steps of forming on the surface of a substrate (110) a cathode (112), forming on the cathode (112) a dielectric layer (114), forming an emitter well (115) in the dielectric layer (114), forming within the emitter well (115) an electron emitter structure (118) having a surface (123), forming on a portion of the dielectric layer (114) a gate electrode (116), depositing on the dielectric layer (114) a sacrificial layer (210), thereafter depositing on the surface (123) of the electron emitter structure (118) a coating material (220, 320, 420) that has an emission-enhancing material, and then removing the sacrificial layer (210).

Abstract: A low power impregnated cathode consisting of a pallet, a cup, an inner sleeve, a cap, and an outer sleeve, is characterized in that the diameter of the pellet is less than at least one and half times of the thickness of the pellet, and is characterized in that an outer diameter of the bottom part of the outer sleeve is larger than an outer diameter of the top part thereof.

Abstract: A ceramic cathode fluorescent discharge lamp is provided including a pair of electrodes, a bulb plated with a fluorescent body on an inner surface of same, at least one of said pair of electrodes being a ceramic cathode having a bottomed cylindrical housing including an electron emission material of an aggregate type porous structure of conductive oxide having a first component consisting of at least one of Ba, Sr, and Ca, a second component consisting of at least one of Zr and Ti, and a third component consisting of at least one of Ta and Nb, said aggregate type porous structure having a surface plated with a conductive or semiconductive layer of at least one of carbide, nitride and oxide of Ta or Nb, rare gas being sealed in said bulb, and sealing pressure of said rare gas being in the range between 10 Torr and 170 Torr.

Abstract: There is disclosed a long-lived thermal field emission electron gun for use in a scanning electron microscope. The gun has a tungsten tip. The surface of this tip is coated with zirconium, zirconium oxide, titanium or titanium oxide. A wire member is mounted above the front end of the tungsten tip to prevent the coating of zirconium or other material from slipping off.

Abstract: The present invention relates to an electron gun having a grid and a cathode with the cathode having an emissive part (12) which defines a central hole (11) in order to reduce spurious electron emissions from the grid to enhance cooling.

Abstract: A cathode for an electron tube is described that has little deterioration of emission current after long operation, is used as a long-life oxide cathode even with high current density in a CRT, and is economical. An emissive material is adhered onto a substrate that is positioned at one opening of a cylindrical sleeve having a built-in heater coil and that includes nickel as a main component by thermally decomposing carbonate including an alkaline earth metal oxide and at least one element selected from the group consisting of titanium, nickel, zirconium, vanadium, niobium and tantalum.

Abstract: A cold cathode electron emission structure includes an amorphous carbon matrix having cesium dispersed therein, with the cesium present in substantially non-crystalline form. A cesium-carbon-oxide layer is positioned on the amorphous carbon matrix, constitutes an electron emission surface and causes the cold cathode electron emission structure to exhibit a lowered surface work function. A display structure including the aforedescribed cold cathode electron emission structure further includes a target electrode including a phosphor and exhibiting a target potential for attraction of electrons. A gate electrode is positioned between the electron emission structure and the target electrode and is biased at a gate potential which attracts electrons, but which is insufficient, in combination with the target potential, to cause emission of a beam of electrons from the electron emission structure.

Abstract: An electrode structure for use in a sealed arc lamp is described. The electrode structure includes a tungsten containing rod surrounded by a block of sintered tungsten containing powder. The block may be impregnated with a thermally conductive material such as copper, silver or braze, and may have a high thermal emissivity surface.

Abstract: An electric discharge tube or discharge lamp, in particular a flat-panel display screen, includes one or more low-temperature cathodes having a holder, which, optionally, is provided with a heating or cooling element, a conductive bottom layer which is applied to the holder, optionally a substrate with dispenser material, and a top coating of ultrafine particles having a nanostructure. The top coating has a surface layer consisting of an emitter complex formed from an emission material comprising several components. The cathodes have a high reliability and a long service life under a normal working load. The emission is stable, which contributes to a constant picture quality throughout the life of the discharge lamp or discharge tube. The discharge tubes or discharge lamps in accordance with the invention have short switching times and the advantage that their construction has been simplified and that their energy consumption is low.

Abstract: A directly heated cathode structure includes a porous pellet impregnated with a thermionic emission material, a supporter for applying electrical power, and a filament fixed to the porous pellet, having an end, and fixed to the supporter, wherein the filament includes a connecting portion wider than the filament and fixed to the supporter at the end of the filament. The cathode structure is suitable for a color CRT such as a color television or a CRT for industrial use and having a large screen.

Abstract: Lamps that include composite sintered electrodes with improved properties that make them suitable for use in a variety of lamp types, are provided by a method for producing electrodes which comprise a refractory metal and a refractory emitter oxide, either single layer or multiple layer, the composites having been subjected to sintering at an elevated temperature effective to form a composite electrode having a density of at least 85%, preferably in the presence of a sintering activator, such as for example, Ni, or mixture thereof with a sintering aid such as, for example Li.sub.2 O.

Abstract: A directly heated cathode structure includes at least one porous pellet containing electron emission material and filaments secured to at least three side surfaces of the porous pellet to support the pellet stably and prevent vibration caused by shock and potential deformation. Each filament is supported by an insulating block and more than one pellet may be mounted on a single insulating block. As a result, a highly reliable cathode ray tube can be manufactured.

Abstract: Disclosed is a thermionic cathode for electron tubes comprising a material that has a substrate, a compound of an element forming an emitting monolayer, chosen from among the rare earth zirconates, rare earth hafnates, rare earth aluminates and rare earth berylates, and a reducing agent which, at the working temperature of the cathode, reacts with the compound releasing the element that forms the monolayer. Application in particular to electron grid tubes. FIG. 1.

Abstract: A method is provided of preparing an impregnated cathode with enhanced thionic emission from a porous billet by impregnating the billed with a suitable impregnant in the presence of an oxygen deficient compound. Additives such as Ir, Os, and Rh react in such a way as to increase emission by reacting to generate oxygen deficient compounds such as WO.sub.2. Moreover, intermediate oxygen sufficient products formed in the chemical reactions can be used as impregnants providing they generate oxygen deficient compounds in the presence of the active emissive material.

Abstract: The present invention relates to a cathode assembly employing a cermet pellet and a method for manufacturing the same. The cathode assembly of the present invention has a good quality such as a low work function and an enhanced life span as compared with the conventional cathode assembly. Also, since the method for manufacturing a cermet pellet is more simplified than that of the cermet thin film, the cathode assembly employing the cermet pellet according to the present invention can be manufactured with ease and at a low cost.

Abstract: A cathode for an electron tube has an electron emissive material layer on the surface of a cathode base metal. The electron emissive material layer has a three-layer structure composed of a first layer made of an alkaline earth metal oxide which is formed on the surface of the cathode base metal, a second layer which is an alkaline earth metal oxide layer in which a rare earth metal oxide is dispersed, which is formed on the surface of the first layer, and a third layer made of an alkaline earth metal oxide which is formed on the surface of the second layer.

Abstract: An impregnation type cathode for a cathode ray tube includes a porous cathode piece having electron emission material impregnated therein. The porous cathode piece has a layer of W--Sc (or a layer of W--Sc.sub.2 O.sub.3) on its surface and a layer of alloy formed of at least two elements of a group of elements consisting of Ir, Os, Ru, and Re on the layer of W--Sc (or the layer of W--SC.sub.2 O.sub.

Abstract: The invention relates to a controllable thermionic electron emitter for vacuum tubes, which comprises an emitter layer (3, 27) and a control layer (5) which is separated from the emitter layer by an insulating layer (4), with the insulating layer and the control layer being manufactured by a deposition process. Also when its dimensions are small, such an electron emitter can be dimensionally accurately manufactured. All functional elements of the controllable thermionic electron emitter, more particularly control layer(s) (5, 7, 22, 24), emitter layer (3, 27) and separating insulating layers (2, 4, 6, 21, 23, 25) are successively deposited on a substrate (1, 20) in the direction of growth, in such a manner that the layers adhere to each other via solid boundary layers. In operation and, in particular, when the temperature varies, the dimensional accuracy of the electron emitter is preserved within narrow limits, and said electron emitter has a long service life.

Abstract: A cathode structure comprises at an end portion (1) an electron-emitting material (4) and a heating element (5) of wire (7), said cathode structure having a plurality of primary helical turns (8). These primary turns are used to form a first series of secondary turns (9) which are wound in a first direction with a pitch and which extend towards the end portion (1), and to form a second series of secondary turns (10) which extend from the end portion (1) and which have the opposite direction of winding yet the same pitch. Near the end portion (1), the first and second series of turns (9, 10) are interconnected by an arc-shaped connecting portion (12) having primary turns (8). This arc-shaped connecting portion (12) has a span S.sub.a and a rise r.sub.a, the ratio r.sub.a /S.sub.a preferably ranging from 0.3 to 0.5.

Abstract: A directly heated cathode structure includes a porous pellet impregnated with an electron radiating material, a cup-shaped container holding the porous pellet, a metal member welded to the container, and a filament between the container and the metal member, restricting thermionic emission through the base and sides of the pellet and extending the life of the cathode structure.

Abstract: A directly heated cathode structure includes a porous pellet impregnated with a cathode material, a first metal member fixed to a surface of the porous pellet, a second metal member welded to the first metal member, and a filament interposed between the first and second metal members. A method for manufacturing a directly heated cathode structure includes manufacturing a porous pellet having a multiplicity of cavities, welding a first metal member to a surface of the porous pellet with a brazing layer, impregnating the cavities of the pellet with an electron radiating material, and welding a second metal member to the first metal member with a filament disposed between the first and second metal members. The useful life of the cathode structure is prolonged since thermions are not emitted through the surface of the pellet covered by the metal member.

Abstract: A thermion emitting oxide cathode comprising a metal cap and a cathode sleeve, the metal cap being coated with a thermion emitting material layer containing a barium-based alkaline earth metal, wherein the thermion emitting material layer is made of a titanate of the barium-based alkaline earth metal. The thermion emitting oxide cathode is made by mixing a titanium tetrachloride (TiCl.sub.4) with an aqueous solution of barium-strontium-calcium dichloride ?(Ba--Sr--Ca)Cl.sub.2 !, dropping the mixture into an oxalate solution of 80.degree. C., thereby precipitating a barium-strontium-calcium titanate hydrate ?(Ba--Sr--Ca)TiO(C.sub.2 O.sub.4).sub.2.4H.sub.2 O!, and treating the precipitated barium-strontium-calcium titanate hydrate at a temperature of 500.degree. to 700.degree. C. to remove a plurality of water molecules, thereby producing a suspension of barium-strontium-calcium titanate ?(Ba--Sr--Ca)TiO.sub.3 !.

Abstract: A directly heated cathode structure includes a porous pellet impregnated with a cathode material, filaments connected to the porous pellet, a support supporting the filament, and an insulation block supporting the support, wherein the filaments are supported on the porous pellet by at least one auxiliary member. The supporting structure is very strong and the quality and productivity can be greatly improved by improvement of the filament welding process using the auxiliary members.

Abstract: A method of manufacturing a dispenser cathode, in which method a powder of a refractory metal and a scandium-containing powder are mixed with each other and pressed to form a cathode body. According to the invention at least both these powders and a suitable binder are mixed with each other to form a homogeneous suspension prior to the pressing operation and the whole mixture is subsequently cured and ground to granules having a larger average size and hence a greater fluidity than the grains of the starting powders. Subsequently the granules thus obtained are pressed to form a cathode body (2). The invention leads to a better processibility and greater convenience of handling of the starting powders so that notably very fine starting powders can be used, which results in cathodes (1) having a better recovery after ion bombardment as compared with cathodes manufactured in conventional manners which are necessarily based on relatively coarse powders.

Abstract: The lifetime of cold-start fluorescent lamps is increased, and the ability to withstand repeated ON-OFF switching cycles enhanced by coating the electrodes with an emitter which consists of barium oxide and a small portion of metallic barium and, optionally, up to 20 mol-% of strontium oxide and a small portion of metallic strontium, preferably only up to about 5 mol-% of strontium oxide--metallic strontium. To make the emitter, barium carbonate, optionally mixed with strontium carbonate, is applied in paste form to the electrodes which, when coated, are introduced into an envelope and sealed therein. The envelope is then evacuated, and the electrodes are heated,thus converting the barium carbonate to barium oxide and metallic barium, and the strontium carbonate, if present, to strontium oxide and metallic strontium, so that the electrodes will be coated with barium oxide, optionally strontium oxide, and metallic barium and optionally metallic strontium.

Abstract: A dispenser cathode including a dispenser body formed of a metal matrix and an emission surface formed of emission material impregnated into the dispenser body metal matrix. The metal matrix is a porous sintered metal matrix containing at least one metal frown a first group (W, Mo, Cr) and at least one metal of a second group (Fe, Co, Ni, Ru, Rh, Pd, Re, Os, Ir, Pt) and chromium oxide. The chromium oxide and the metals from the two groups are provided as a powder mixture to form the matrix. The emission material includes at least two alkaline earth metal oxides such as CaO, BaO and at least one oxide of a metal of group IIIa or IIIb of the Periodic Table. The oxide of a metal group is Al.sub.2 O.sub.3.

Abstract: Cathode including a solid body (4) which comprises metallic constituents (particularly W, Ni, Mg, Re, Mo, Pt) and oxidic constituents (such as particularly BaO, CaO, Al.sub.2 O.sub.3, Sc.sub.2 O.sub.3, SrO, ThO.sub.2, La.sub.2 O.sub.3).Also at low operating temperatures, high emission current densities and a long lifetime are achieved in that the structure of the constituents and the volume ratio v.sub.m of the metallic constituents relative to the overall volume of the solid body are chosen to be such that the resistivity .rho. has a value in the range of .rho..sub.0 .multidot.10.sup.-4 >.rho.>.rho..sub.m .multidot.10.sup.2, in which .rho..sub.0 and .rho..sub.m are the resistivities, defined at 20.degree. C., of the pure oxidic constituents and the pure metallic constituents, respectively.

Abstract: An oxide cathode is provided including a metal base, an electron emissive material layer formed on the metal base and having barium as a main component, a heater for heating the electron emissive material layer, and a Ba evaporation restraining layer having a thickness ranging from 10.ANG. to 10,000.ANG. and consisting of at least one titanium compound formed on the electron emissive material layer.

Abstract: A thermionic cathode having an overcoating of emissive material having a position including a mixture Aluminum Tungstate and Scandium Tungstate which react, when heated, to provide the cathode with enhanced electron emissions.

Abstract: A method of manufacturing a thermionic cathode structure comprises the steps of: (1) forming a mixture of (a) tungsten powder, (b) at least one of the group comprising alumina or zirconia or yttrium oxide powder, (c) alkaline earth metal carbonate powder, and (d) a binder, (2) pressing the mixture isostatically causing the mixture to adhere to form an electrically insulating body, (3) sintering the body in a dry hydrogen ambient thereby reducing the carbonate, and (4) coating the surface of the body or a portion of the surface with a poly-crystalline metal layer.

Abstract: A low-power cathode can be obtained by arranging it on a substrate (1), preferably of silicon, which is entirely or partly removed at the location of the emissive structure (11) by means of, for example, anisotropic etching. Because of its low power, the cathode is particularly suitable for multi-beam applications.

Abstract: An impregnated cathode structure has: (1) a sleeve having a truncated conically-shaped top portion with an opening having a predetermined diameter at the center thereof; (2) oxide cathode material formed within and conforming to the shape of the sleeve to form a point exposed through the opening; (3) a receiver forming part of said sleeve for retaining the oxide cathode material; (4) a backing plug which divides the inside of the sleeve so as to form a space for the receiver; and (5) a heater installed in the sleeve below the backing plug.

Abstract: An impregnated pellet for a cathode structure according to the present invention is produced by forming a plurality of voids by arranging a plurality of metal rods within a cylinder of heat-resisting metal open at both ends thereof, impregnating the voids with electron emission material, thereby to prepare a rod-shaped pellet base, cutting the rod-shaped pellet base into respective impregnated pellets of a predetermined thickness, and finishing the cut surfaces of the pellets by vibration and tilting operation of working plate. The impregrate pellets can be extensively applied to a cathode-ray tube, an electron tube and the like, which require high current density.

Abstract: A display apparatus for displaying pictures virtually instantaneously adopts a direct-heating type cathode of an impregnated structure, and includes a cathode ray tube having a dispenser cathode wherein a cathode material is filled in pores of a porous body and a porous heater is directly connected to the cathode material. A voltage generator of the apparatus produces a first voltage for driving the heater. A video signal supply portion supplies a video signal to the cathode, while a deflector deflects horizontally and vertically an electron beam generated from the cathode to produce a raster by scanning the fluorescent surface of the cathode ray tube. A flyback transformer generates a second voltage to be supplied to the anode and one or more grids of the cathode ray tube using a horizontal deflection output signal supplied from the deflector. With the described arrangement, an electron-emitting velocity of an electron gun reaches its maximum value within about one second after power is applied.

Abstract: A cathode in an MPD thruster has an internal heater and utilizes low work function material. The cathode is preheated to operating temperature, and then the thruster is fired by discharging a capacitor bank in a pulse forming network.

Abstract: The initial emission and the lifetime of oxide cathodes are considerably improved by adding small quantities of rare earth metals (10-500 ppm).

Abstract: The invention relates to a manufacturing process for an impregnated cathode for an electron tube and the impregnated cathode obtained in this manner. The method consists in mixing (b) a powder (Y) containing the emissive elements (generally barium and calcium aluminates) with powder (W) of at least one refractory metal (generally tungsten, if necessary mixed with a platinum ore metal), then pressing (c) this mixture into a pellet (1) which is then sintered (d) at a high temperature in hydrogen (approx. 2000.degree. C.). In the prior art of this method, a powder of at least one refractory metal was pressed and sintered and then impregnated, machined, cleaned, etc. The process according to the invention therefore saves many steps in the manufacture of an impregnated cathode with respect to the prior art.

Abstract: To maintain a monolayer of scandium, which is necessary for a satisfactory emission on the surface of a scandate cathode, at least the top layer of the cathode is provided with a scandium-containing oxidic phase from which Scandium is supplied by segregation of scandium from this oxidic phase.

Abstract: An impregnated cathode including an electron emissive substance in a porous matrix of a metal having a high melting point and a heat resistive property, is manufactured by mixing (S2) powder of the metal and the electron emissive substance in a dry state into cathode forming powder, press-shaping (S3) the cathode forming powder into a shaped body, sealing (S4) the shaped body in a reaction vessel to provide a sealed vessel, and subjecting (S5) the shaped body in the sealed vessel to a hot isostatic press (HIP) to provide a sintered body of the cathode forming powder, wherein the substance comprises a barium aluminate compound represented by a chemical formula of:(pBaO.qCaO).nBaAl.sub.2 O.sub.4,where p represents an integer which is not less than one, q representing an integer which is not less than zero, n representing an integer which is not less than one. Preferably, the HIP is carried out at a temperature between 900.degree. C. and 1400.degree. C.

Abstract: A method is provided of preparing an impregnated cathode with enhanced thionic emission from a porous billet by impregnating the billet with a suitable impregnant in the presence of an oxygen deficient compound.

Abstract: To maintain a monolayer of scandium, which is necessary for a satisfactory emission on the surface of a scandate cathode, at least the top layer of the cathode is provided with a scandium-containing oxidic phase from which Scandium is supplied by segregation from this oxidic phase.

Abstract: In a mercury vapor arc discharge tube having a pair of electrodes, an emissive material disposed on the electrodes consists essentially of a single phase compound of Ba.sub.x Sr.sub.1-x Y.sub.2 O.sub.4 where x is from about 0.25 to about 0.95.

Abstract: A reservoir dispenser cathode structure having improved thermal efficiency is provided by inner and outer subassemblies. The inner subassembly has a molybdenum heater cup to which a tungsten-rhenium alloy cap is laser seam-welded. The outer subassembly has a tantalum support cylinder within which the inner subassembly is supported by means of a three-point suspension in the form of tabs that are lanced from the tantalum cylinder and spot-welded to the heater cup. The heater has a coiled-coil design wherein the coils are coated with Al.sub.3 O.sub.3 and small particle tungsten powder to increase the coil's thermal emissivity. This thermally-efficient structure permits the achievement of high current density (greater than 3 Amperes per square centimeter) with heater power that is less than 1.3 Watts.