Cathodes Containing And/or Coated With Electron Emissive Material Patents (Class 313/346R)
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Patent number: 5838096Abstract: A cathode includes a hairpin type filament made of a refractory metal such as W, Mo or Re; a single crystal needle, made of a refractory metal such as W, Mo or Re joined to the filament; and a reservoir formed by applying a slurry of a powder of a metal or metal compound and an organic solvent containing nitrocellulose in the vicinity of a junction between the single crystal needle and the filament. The powder for a reservoir is made of a metal lower than the single crystal needle in a work function or electron affinity, such as Ti, Zr, Hf, Y, Th, Sc or Se, or a compound thereof.Type: GrantFiled: July 12, 1996Date of Patent: November 17, 1998Assignee: Hitachi, Ltd.Inventors: Hiroyuki Shinada, Satoru Fukuhara, Katsuhiro Kuroda
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Patent number: 5831382Abstract: A novel self-supporting flat display screen based on thermionic emission of indirectly heated cathode structures (23, 30, 31, 32, 34; 230, 32, 34) is provided utilizing micro-filament heaters (21) that can be interconnected in any predetermined manner. The planar micro-filament (21) construction utilizes Dewer and Dewer-like techniques (10, 11, 12, 13, 14, 15) for controlling the thermal energy emitted and lowering the power consumption of a display device. Several control electrode techniques (42, 52, 33, 133, 142) are also incorporated in the invention to reduce the voltage levels required to control the display and simplify the overall electronic control circuitry needed by the display device. These techniques are combined to provide a high intensity, high contrast flat panel display using low voltage off-the-shelf electronic driver circuitry.Type: GrantFiled: September 27, 1996Date of Patent: November 3, 1998Inventors: Frank Albert Bilan, Jules Joseph Jelinek
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Patent number: 5828165Abstract: 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.Type: GrantFiled: March 4, 1997Date of Patent: October 27, 1998Assignee: Thomson-CSFInventors: Guy Clerc, Jean de Cachard
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Patent number: 5828164Abstract: 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.Type: GrantFiled: May 14, 1996Date of Patent: October 27, 1998Assignee: The United States of America as represented by the Secretary of the ArmyInventors: Louis E. Branovich, Donald W. Eckart, Paul Fischer
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Patent number: 5821683Abstract: 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.Type: GrantFiled: February 3, 1997Date of Patent: October 13, 1998Assignee: Samsung Display Devices Co., Ltd.Inventors: Kyu-nam Joo, Jong-seo Choi, Geun-bae Kim, Kwi-seuk Choi, Sang-won Lee
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Patent number: 5811916Abstract: Applicants have discovered methods for making, treating and using diamonds which substantially enhance their capability for low voltage emission. Specifically, applicants have discovered that defect-rich diamonds--diamonds grown or treated to increase the concentration of defects--have enhanced properties of low voltage emission. Defect-rich diamonds are characterized in Raman spectroscopy by a diamond peak at 1332 cm.sup.-1 broadened by a full width at half maximum .DELTA.K in the range 5-15 cm.sup.-1 (and preferably 7-11 cm.sup.-1). Such defect-rich diamonds can emit electron current densities of 0.1 mA/mm.sup.2 or more at a low applied field of 25 V/.mu.m or less. Particularly advantageous structures use such diamonds in an array of islands or particles each less than 10 .mu.m in diameter at fields of 15 V/.mu.m or less.Type: GrantFiled: November 19, 1996Date of Patent: September 22, 1998Assignee: Lucent Technologies Inc.Inventors: Sungho Jin, Gregory Peter Kochanski, Lawrence Seibles, Wei Zhu
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Patent number: 5808404Abstract: 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.Type: GrantFiled: September 9, 1996Date of Patent: September 15, 1998Assignee: Hitachi, Ltd.Inventors: Sachio Koizumi, Toshifumi Komiya
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Patent number: 5793157Abstract: A cathode ray tube has a cathode structure including a cathode body comprised of porous refractory metal impregnated with electron-emissive material, a metal cup for containing the cathode body therein, a metal sleeve having a closed end and mounting a heater therein, a cylindrical metal eyelet and a plurality of thin metal wires stretched across one end of the metal eyelet and suspending the metal cup and the metal sleeve concentrically with and in the cylindrical metal eyelet. The metal cup and the closed end of the metal sleeve are fixed with the plurality of thin metal wires interposed therebetween, and ends of the plurality of thin metal wires are welded to a metal flange formed at the one end of the metal eyelet. The metal cup can be welded to the closed end of the metal sleeve by an electron beam with the plurality of thin metal wires interposed therebetween.Type: GrantFiled: March 14, 1996Date of Patent: August 11, 1998Assignees: Hitachi, Ltd., Hitachi Electronic Devices Co., Ltd.Inventors: Hiroshi Takakura, Takashi Kono, Michihide Shibata, Yasuhiko Nonaka
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Patent number: 5793153Abstract: In a comb-like or wedge-like electron emitting device, an emitter or both an emitter and an anode electrode are processed from a single-crystal silicon thin film of an SOI wafer. The single-crystal silicon thin film in portions other than the processed portion is removed so that the silicon oxide layer is dug down further slightly. A gate electrode for applying an electric field in order to draw electrons out of the emitter is provided in the dug-down portion. When the end and side faces of the emitter are formed as (111) faces by anisotropic etching in the condition that the single-crystal silicon thin film is oriented to a (100) face, the emitter has a sharp edge at about 55.degree. with respect to the substrate. In a conical electron emitting device, the gate electrode is constituted by a single-crystal silicon thin film of an SOI wafer so that a pyramid surrounded by the (111) faces is formed on the single-crystal silicon substrate.Type: GrantFiled: August 8, 1995Date of Patent: August 11, 1998Assignees: Fuji Electric Co., Ltd., Director-General, Jiro Hiraishi, Agency of Industrial Science and TechnologyInventors: Junji Itoh, Takahiko Uematsu, Yoichi Ryokai, Masato Nishizawa, Kazuo Matsuzaki
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Patent number: 5773922Abstract: A direct heating cathode for electron guns and a process for producing such a cathode are disclosed. The above direct heating cathode achieves a high current density, extends the expected life span and simplifies the cathode producing process. In the process for producing the above cathode, powdered iridium (Ir) as a basic ingredient is mixed with powdered cerium (Ce) as a subsidiary ingredient at a given mixing ratio into a powdered metal mixture. The powdered metal mixture in turn is applied with a mechanical impact through high energy ball milling, thereby being mechanically alloyed into alloy powder. The alloy powder is compressed with a given pressure, thereby being formed into an alloy pellet. The alloy pellet in turn is heated to remove residual gases from the pellet. Thereafter, the electron emitting performance of the pellet is tested.Type: GrantFiled: November 30, 1995Date of Patent: June 30, 1998Assignee: Samsung Display Devices, Co., Ltd.Inventors: Kwang-Min Lee, Kyu-Nam Joo, Jong-Seo Choi, Geun-Bae Kim, Kwi-Seuk Choi
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Patent number: 5764004Abstract: Method and apparatus are presented for the generation, regeneration, and transplantation of field enhancing whiskers to provide for an improved cathode in flat panel displays in particular, and in other applications. Such applications comprise devices in which there is an emissive cathode structure for producing electrons. There are clear advantages for the instant invention in the case of a flat panel display which requires a relatively large cathode area, because the present invention avoids excessive power loss due to radiation and conduction loss by permitting operation of the cathode at a significantly lower temperature than if it operated solely as a thermionic emitter. The combination of moderately elevated temperature and enhanced electric field allows the advantages of thermo-field assisted emission.Type: GrantFiled: February 28, 1997Date of Patent: June 9, 1998Inventor: Mario Rabinowitz
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Patent number: 5763997Abstract: A matrix addressable flat panel display includes a flat cathode operable for emitting electrons to an anode when an electric field is produced across the surface of the flat cathode by two electrodes placed on each side of the flat cathode. The flat cathode may consist of a cermet or amorphic diamond or some other combination of a conducting material and an insulating material such as a low effective work function material. The electric field produced causes electrons to hop on the surface of the cathode at the conducting-insulating interfaces. An electric field produced between the anode and the cathode causes these electrons to bombard a phosphor layer on the anode.Type: GrantFiled: June 1, 1995Date of Patent: June 9, 1998Assignee: SI Diamond Technology, Inc.Inventor: Nalin Kumar
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Patent number: 5763880Abstract: A cathode (e.g., a Schottky emission cathode) having an electron emitter of a tungsten single-crystal with a sharp point, and a heater connected to the electron emitter to heat it. The work function of the crystal face of the point of the electron emitter is reduced by providing adsorbed thereon a nitride of Zr, Ti, Y, Nb, Sc, V or La, or an oxide of Y, Sc, V or La. The nitride or oxide can be formed as a reservoir on the heater (from where it thermally diffuses to the point), or chemically adsorbed on the point. For forming the nitride or oxide on the point, the metal forming the nitride or oxide can be provided on the point and reacted with nitrogen or oxygen thereat to form the nitride or oxide; to provide the metal on the point, the metal forming the nitride or oxide can either be evaporated onto the point, or can form a reservoir on the heater and thermally diffuse therefrom to the point.Type: GrantFiled: March 4, 1996Date of Patent: June 9, 1998Assignee: Hitachi, Ltd.Inventors: Hidetoshi Nisiyama, Masakuni Okamoto, Hiroyuki Shinada, Katsuhiro Kuroda
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Patent number: 5760417Abstract: In a semiconductor electron emission device for causing an avalanche breakdown by applying a reverse bias voltage to a Schottky barrier junction between a metallic material or metallic compound material and a p-type semiconductor, and externally emitting electrons from a solid-state surface, a p-type semiconductor region (first region) for causing the avalanche breakdown contacts a p-type semiconductor region (second region) for supplying carriers to the first region, and a semi-insulating region is formed around the first region.Type: GrantFiled: March 27, 1995Date of Patent: June 2, 1998Assignee: Canon Kabushiki KaishaInventors: Nobuo Watanabe, Norio Kaneko, Masahiko Okunuki, Takeo Tsukamoto
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Patent number: 5757130Abstract: A lamp for emitting in the visible portion of the spectrum, which utilizes a fill which includes a selenium and/or a sulfur containing substance. The lamp has superior performance characteristics. Special electrode structures are provided which enhance longevity.Type: GrantFiled: June 7, 1995Date of Patent: May 26, 1998Assignee: Fusion Lighting, Inc.Inventors: James T. Dolan, Michael G. Ury, Charles H. Wood, John F. Waymouth
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Patent number: 5757115Abstract: With a production of a cathode member for an electron tube having cathode materials containing Ni, a metal having a reduction behavior and an electron emissive agent sintered to be one body and its electron emitting surface subjected to a specular processing, it is possible to obtain an inexpensive cathode characterized by that: the operation temperature is low; the electron emission distribution is excellent because of the smooth electron emitting surface; and the electron emission is enabled with a high current density for a long interval of time.Type: GrantFiled: May 31, 1995Date of Patent: May 26, 1998Assignee: NEC CorporationInventors: Maki Narita, Toshikazu Sugimura, Hiroyuki Sakatani, Tsuyoshi Tanabe
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Patent number: 5747921Abstract: 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.Type: GrantFiled: March 17, 1997Date of Patent: May 5, 1998Assignee: Goldstar Co., Ltd.Inventor: Yeoung Ku Kim
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Patent number: 5744905Abstract: The present invention is directed to new electrode structures for use in fluorescent lamps in which a tungsten base structure is provided with electron emissive materials including one or more of barium titanate, barium zirconate, barium strontium zirconate, barium cerium oxide, barium tantalate, and barium strontium yittrium oxide. Amounts of MgO may be added to improve or change emitter properties. A composite electrode structure can be formed by way of coating a tungsten coil with a slurry of this material, or providing powdered mixtures of both the electron emissive material and tungsten material and sintering this powdered material into a high density composite electrode structure.Type: GrantFiled: August 19, 1997Date of Patent: April 28, 1998Assignee: Philips Electronics North America CorporationInventors: Vivek Mehrotra, Hemant S. Betrabet, David Robert Woodward, Thomas O. Leyh, Susan McGee
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Patent number: 5735720Abstract: 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.Type: GrantFiled: March 11, 1997Date of Patent: April 7, 1998Assignee: U.S. Philips CorporationInventors: Georg Gartner, Hans-Jurgen Lydtin
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Patent number: 5729082Abstract: 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.Type: GrantFiled: July 9, 1996Date of Patent: March 17, 1998Assignee: U.S. Philips CorporationInventor: Franciscus M. M. Snijkers
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Patent number: 5726524Abstract: An electric field emission device includes an electrode that includes a layer having a dense array of discrete, solid microstructures disposed on at least a portion of one or more surfaces of a substrate, the microstructures having an areal number density of greater than 10.sup.7 /cm.sup.2, the microstructures being individually conformally overcoated with one or more layers of an electron emitting material, the overcoated electron emitting material being disposed on at least a portion of the microstructures and have a surface morphology which is nanoscopically rough. A method for preparing the electrode used in the invention is discussed.Type: GrantFiled: May 31, 1996Date of Patent: March 10, 1998Assignee: Minnesota Mining and Manufacturing CompanyInventor: Mark K. Debe
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Patent number: 5712490Abstract: A photocathode device is disclosed including an active layer, a composition ramp layer and an emission layer including an emission surface. The active layer, ramp layer and emission layer each have both a predetermined material composition and a predetermined doping level for maintaining the conduction band of the device flat until the emission surface which functions to increase the photoresponse of the device.Type: GrantFiled: November 21, 1996Date of Patent: January 27, 1998Assignee: ITT Industries, Inc.Inventor: Arlynn W. Smith
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Patent number: 5712531Abstract: The invention concerns high-pressure discharge lamps, whose electrodes have a sintered compact (5) containing lanthanum oxide acting as an electron emitter, and this compact is surrounded by an electrode coil (6). Sintered compact (5) contains at least 90 weight % lanthanum oxide. In this way, a high thermal stability of sintered compact (5) and a good ignition performance of the lamp are assured with only negligible blackening of the discharge vessel over the service life of the lamp.Type: GrantFiled: July 30, 1996Date of Patent: January 27, 1998Assignee: Patent - Truehand - Gesellshaft fuer electrishe Gluelampen mbHInventors: Albert Rademacher, Ulrich Rosner
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Patent number: 5710435Abstract: A photoelectric emission surface which is excellent in stability and reproducibility of photoelectric conversion characteristics and has a structure capable of obtaining a high photosensitivity is provided. A predetermined voltage is applied between an upper surface electrode and a lower surface electrode by a battery. Upon application of this voltage, a p-n junction formed between a contact layer and an electron emission layer is reversely biased. A depletion layer extends from the p-n junction into the photoelectric emission surface, and an electric field is formed in the electron emission layer and a light absorbing layer in a direction for accelerating photoelectrons. When incident light is absorbed in the light absorbing layer to excite photoelectrons, the photoelectrons are accelerated by the electric field toward the emission surface.Type: GrantFiled: December 20, 1995Date of Patent: January 20, 1998Assignee: Hamamatsu Photonics K.K.Inventors: Minoru Niigaki, Toru Hirohata, Tomoko Suzuki, Masami Yamada
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Patent number: 5708326Abstract: A fluorescent display device including a cathode filament increased in mechanical strength and reduced in end cool. A 26% Re-W filament of 0.64 MG (corresponding to 0.64 mg in weight per 20 cm in length) exhibits an end cool as small as 4.2 mm on each of both sides thereof at a temperature of about 580.degree. C. The end cool in a conventional W filament of the same diameter is increased to about 8 mm. The 26% Re-W filament is increased in mechanical strength by 50% as compared with the conventional W filament.Type: GrantFiled: May 28, 1996Date of Patent: January 13, 1998Assignees: Futaba Denshi Kogyo K.K., Toshiba CorporationInventors: Tadashi Mizohata, Masashi Suzuki
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Patent number: 5708321Abstract: A cathode for an electron tube includes a base metal containing nickel as a major component and an electron-emissive material layer which is formed on the base metal and comprises an alkaline earth metal oxide including barium oxide as its main component, wherein the electron-emissive material layer further comprises a lanthanum-magnesium-manganese oxide. The cathode of the present invention is fully interchangeable with conventional oxide cathodes and has a longer lifetimes and an improved cut-off drift characteristic.Type: GrantFiled: April 10, 1996Date of Patent: January 13, 1998Assignee: Samsung Display Devices Co., Ltd.Inventors: Kyu-nam Joo, Jong-seo Choi, Kwi-seuk Choi, Geun-bae Kim, Sang-won Lee
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Patent number: 5703429Abstract: 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.Type: GrantFiled: December 13, 1995Date of Patent: December 30, 1997Assignee: Samsung Display Devices Co., Ltd.Inventors: Chang-seob Kim, Seok-bong Son, Sang-kyun Kim, Bong-uk Jeong
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Patent number: 5703435Abstract: A field emission cathode for use in flat panel displays is disclosed comprising a layer of conductive material and a layer of amorphic diamond film, functioning as a low effective work-function material, deposited over the conductive material to form emission sites. The emission sites each contain at least two sub-regions having differing electron affinities. Use of the cathode to form a computer screen is also disclosed along with the use of the cathode to form a fluorescent light source.Type: GrantFiled: May 23, 1996Date of Patent: December 30, 1997Assignee: Microelectronics & Computer Technology Corp.Inventors: Nalin Kumar, Chenggang Xie
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Patent number: 5701052Abstract: 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.Type: GrantFiled: December 27, 1995Date of Patent: December 23, 1997Assignee: Samsung Display Devices Co., Ltd.Inventors: Chang-seob Kim, Seok-bong Son, Sang-kyun Kim, Bong-uk Jeong
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Patent number: 5698937Abstract: A cathode for an electron tube has a layer of electron-emissive substance containing alkaline earth metal carbonates having capillary crystals, to which 0.01-20.0 wt % of both a lanthanum (La) compound and a magnesium (Mg) compound or an La--Mg compound, based upon the weight of the alkaline earth metal carbonate, is added. The cathode enjoys full interchangeability with a conventional oxide cathode and a 15-20% longer lifetime.Type: GrantFiled: February 23, 1995Date of Patent: December 16, 1997Assignee: Samsung Display Devices Co., Ltd.Inventors: Gyu-nam Ju, Jong-seo Choi, Keun-bae Kim, Kwang-min Lee, Kwi-seok Choi
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Patent number: 5684357Abstract: 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 !.Type: GrantFiled: December 8, 1995Date of Patent: November 4, 1997Assignee: Samsung Display Devices Co., Ltd.Inventors: Kwang-Min Lee, Kyu-Nam Joo, Jong-Seo Choi, Geun-Bae Kim, Kwi-Seuk Choi, Sang-Won Lee
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Patent number: 5668434Abstract: 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.Type: GrantFiled: December 6, 1995Date of Patent: September 16, 1997Assignee: Samsung Display Devices Co., Ltd.Inventors: Chang-seob Kim, Seok-bong Son, Bong-uk Jeong, Sang-kyun Kim, Sang-uk Shin
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Patent number: 5666025Abstract: A flat-panel display contains an emissive cathode structure and a generally flat encapsulating body that surrounds the cathode structure to form a sealed enclosure. The cathode structure contains electronegative atoms (22), which consist of oxygen and/or fluorine, chemically bonded to a carbon-containing cathode (10). Atoms (24R) of electropositive metal are chemically bonded to the electronegative atoms.Type: GrantFiled: October 17, 1995Date of Patent: September 9, 1997Assignee: Candescent Technologies CorporationInventors: Michael W. Geis, John M. Macaulay, Jonathan C. Twichell
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Patent number: 5666022Abstract: 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.Type: GrantFiled: October 7, 1996Date of Patent: September 9, 1997Assignee: U.S. Philips CorporationInventors: Jacobus A. J. M. Deckers, Theodorus H. Weekers, Albert Manenschijn, Franciscus M. M. Snijkers, Petrus A. M. Van Der Heide
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Patent number: 5661362Abstract: A display device consisting of an electron-emitting device which is a laminate of an insulating layer and a pair of opposing electrodes formed on a planar substrate. A portion of the insulating layer is between the electrodes and a portion containing an electron emitting region in between one electrode and the substrate. Electrons are emitted from the electron emission region by a voltage to the electrodes, thereby stimulating a phosphorous to emitting light.Type: GrantFiled: June 3, 1996Date of Patent: August 26, 1997Assignee: Canon Kabushiki KaishaInventors: Seishiro Yoshioka, Ichiro Nomura, Hidetoshi Suzuki, Toshihiko Takeda, Tetsuya Kaneko, Yoshikazu Banno, Kojiro Yokono
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Patent number: 5659224Abstract: A display device for use in conjunction with a computer system includes a cathode having a layer of conductive material and a layer of low-effective work function material deposited over the conductive material wherein the low-effective work function material has an emission surface comprising a plurality of distributed localized electron emission sites. The emission sites may have electrical properties which are discontinuous from each other. The emission surface may be relatively flat.Type: GrantFiled: June 7, 1995Date of Patent: August 19, 1997Assignee: Microelectronics and Computer Technology CorporationInventors: Nalin Kumar, Chenggang Xie
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Patent number: 5656883Abstract: This disclosure is directed toward field emission surfaces, and is more particularly directed toward improvements in cold, low field, high current, low noise field emission devices and surfaces. Such devices are used in field emission display devices such as video displays and information displays. The device utilizes a cermet with graded concentration of insulative and conductive particles deposited on the truncated point of a conical emitter. The emission surface of the cermet is insensitive to gases that oxidize or poison the emission surface. Such gases and other contaminants emanate from a phosphor when the emission device is used in phosphor display devices. The field emission device is operated at lower potentials thereby reducing power requirements and minimizing heat dissipation requirements. Further, the field emission device which operates at lower field in order to reduce mechanically and temporally unstable emission sites which result in current bursts and current deficits at these sites.Type: GrantFiled: August 6, 1996Date of Patent: August 12, 1997Inventor: Alton O. Christensen
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Patent number: 5654606Abstract: A low-pressure discharge lamp according to the invention is provided with a radiation-transmitting discharge vessel which encloses a discharge space containing an ionizable filling in a gastight manner, and electrodes arranged in the discharge space between which a discharge path extends. At least one of the electrodes is a sintered mixture of metal and ceramic material, the proportional quantity of metal in the mixture being small compared with the proportional quantity of ceramic material. The sintered mixture includes smaller ceramic particles with a modal diameter D1 and larger ceramic particles with a modal diameter D2, the ratio D2/D1 being at least 3, while the proportional volume of the smaller ceramic particles is small compared with that of the larger ceramic particles. In the lamp according to the invention, the electrodes have a comparatively high resistance to temperature variations in spite of the small proportional volume of metal particles.Type: GrantFiled: November 6, 1995Date of Patent: August 5, 1997Assignee: U.S. Philips CorporationInventors: Christianus H. L. Weijtens, Detlev Hennings
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Patent number: 5650689Abstract: A field emission element including an electrode structure made of a thin film exhibiting increased adhesive strength. A thin film of niobium nitride (NbN) is formed on a glass substrate by sputtering or the like. The NbN film exhibits increased adhesive strength to a degree sufficient to prevent etching for formation of the film into electrodes from causing peeling of the film.Type: GrantFiled: February 8, 1996Date of Patent: July 22, 1997Assignees: Futaba Denshi Kogyo K.K., Agency of Industrial Science and TechnologyInventors: Shigeo Itoh, Teruo Watanabe, Kazuhiko Tsuburaya, Yoshihiko Hirata, Susumu Takada, Hiroshi Nakagawa
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Patent number: 5646482Abstract: In a DC gas discharge type image display apparatus including: a front glass substrate; a rear glass substrate facing the front glass substrate, interposing a discharge gas therebetween; a set of anodes including a plurality of line electrodes formed on the rear glass substrate; a set of cathodes including a plurality of line electrodes placed on the front glass substrate so as to perpendicularly cross the set of anodes; and a plurality of discharge cells, each being provided so as to correspond to each of the cross points of the set of anodes and the set of cathodes, the apparatus being driven in a refresh driving method or a memory driving method, the set of cathodes are formed by a spraying method. The cathodes are made from aluminum, nickel, an aluminum alloy or a nickel alloy. The discharge gas is a mixed gas of He and Xe.Type: GrantFiled: May 30, 1995Date of Patent: July 8, 1997Assignee: Matsushita Electric Industrial Co., Ltd.Inventors: Shigeo Suzuki, Hidenobu Shintaku, Taku Watanabe, Mitsuo Asabe, Kazuo Takahashi, Yoshiro Abe, Hiroki Kono, Kazunori Hirao
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Patent number: 5633507Abstract: An electron beam system for direct writing applications employs an electron gun having a large emitting surface compared to the prior art and a brightness approximately two orders of magnitude less than prior art systems to illuminate an initial aperture uniformly with a slightly diverging beam that passes efficiently through the aperture, a first set of controllable deflectors to scan the beam over the reticle parallel to the system axis, impressing the pattern of a subfield of the reticle in each exposure, in which a first variable axis lens focuses an image of the initial aperture on the reticle, a second variable axis lens collimates the patterned beam, a second set of controllable deflectors to bring the beam back to an appropriate position above the wafer, and a third variable axis lens to focus an image of the reticle subfield on the wafer, together with correction elements to apply aberration corrections that may vary with each subfield, thereby providing high throughput from the use of parallel proceType: GrantFiled: September 19, 1995Date of Patent: May 27, 1997Assignee: International Business Machines CorporationInventors: Hans C. Pfeiffer, Werner Stickel
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Patent number: 5616926Abstract: A Schottky emission cathode has a filament, a needle-shaped piece of single crystal refractory metal which is attached to the filament and has a flat crystal surface at a tip thereof, and an adsorbed layer including at least one kind of a metal other than the single crystal refractory metal on the flat crystal surface. The piece of single crystal refractory metal is heated by passing a current through the filament and electrons are extracted by an electric field applied on a tip of the needle-shaped piece of single crystal refractory metal. The tip of the needle-shaped piece of single crystal refractory metal as a radius of curvature of a value to produce an energy width among electrons extracted from the tip not exceeding a predetermined value when the electric field is sufficient to prevent the flat crystal surface from collapsing during operation of the cathode.Type: GrantFiled: July 31, 1995Date of Patent: April 1, 1997Assignee: Hitachi, Ltd.Inventors: Hiroyuki Shinada, Shingo Kimura, Katsuhiro Kuroda, Satoru Fukuhara, Takashi Ohshima
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Patent number: 5614784Abstract: 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.Type: GrantFiled: June 15, 1995Date of Patent: March 25, 1997Assignee: Patent-Treuhand-Gesellschaft fur elektrische Gluhlampen mbHInventors: Christian Harzig, Roland Hoffmann, Erolf Weinhardt
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Patent number: 5600200Abstract: A field emission cathode for use in flat panel displays comprises a layer of conductive material and a layer of amorphic diamond film, functioning as a low effective work-function material, deposited over the conductive material to form emission sites. The emission sites each contain at least two sub-regions having differing electron affinities. The cathode may be used to form a computer screen or a fluorescent light source.Type: GrantFiled: June 7, 1995Date of Patent: February 4, 1997Assignee: Microelectronics and Computer Technology CorporationInventors: Nalin Kumar, Chenggang Xie
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Patent number: 5592043Abstract: 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.Type: GrantFiled: April 3, 1996Date of Patent: January 7, 1997Assignee: U.S. Philips CorporationInventors: Georg Gartner, Hans Lydtin
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Patent number: 5585694Abstract: A fluorescent low pressure discharge lamp is provided with axially mounted cold-cathode electrodes consisting of a sintered shaped mixture of inorganic material including about 50-90% by weight of tungsten and the remainder BaO or a mixture of BaO, CaO and SrO and oxides of Y, Zr or Hf or the rare earths. The electrodes have a uniform density throughout with a porosity of less than 10%.Type: GrantFiled: August 10, 1992Date of Patent: December 17, 1996Assignee: North American Philips CorporationInventors: Efim Goldburt, David R. Woodward
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Patent number: 5576051Abstract: A multiple electron emission device having a substrate, a pair of opposed electrodes disposed on the substrate, and an electron emission section formed with grains between the electrodes. Selected portions of the electron emission section are coated with a conductor, semiconductor or insulating material by mask deposition or the like so as to divide the electron emission section into a dotted or linear array of electron emitting portions.Type: GrantFiled: December 1, 1993Date of Patent: November 19, 1996Assignee: Canon Kabushiki KaishaInventors: Toshihiko Takeda, Ichiro Nomura, Tetsuya Kaneko, Yoshikazu Banno
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Patent number: 5576699Abstract: In a method for transferring information in a form of electron beam, an electron beam detector detects the electron beam, and emission of the electron beam from a predetermined electron beam source is controlled in accordance with a signal from the detector upon detection of the electron beam. A deflection electrode is also used to deflect the electron beams according to an electric or magnetic field to perform charge shifting, logical additions, logical multiplications, image formation, and the like.Type: GrantFiled: May 24, 1995Date of Patent: November 19, 1996Assignee: Canon Kabushiki KaishaInventors: Fumitaka Kan, Kenji Nakamura, Masanori Takenouchi, Naoji Hayakawa, Isamu Shimoda, Masahiko Okunuki
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Patent number: 5559342Abstract: An electron emitting device causes electron emission by a current supply in a coarse resistor film. The coarse thin resistor film is composed at least of a coarse thin silicon film.Type: GrantFiled: April 6, 1995Date of Patent: September 24, 1996Assignee: Canon Kabushiki KaishaInventors: Takeo Tsukamoto, Akira Shimizu, Akira Suzuki, Masao Sugata, Isamu Shimoda, Masahiko Okunuki
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Patent number: 5557168Abstract: A panel-shaped gas-discharging type display device includes an anode and a cathode having a special shape to enhance discharging in an airtight chamber formed by two substrates. A gas containing an ultraviolet emission gas such as Xe and Kr and a fluophor for emitting a light are put together into the airtight chamber. Because of the shape of the cathode, more discharging occurs than with conventional devices. More ultraviolet emission from the discharging excites the fluophor to create a visible radiation. Therefore, the brightness of the device increases. Since the cathode is coated with an emitter material incapable of absorbing the ultraviolet emission gas, discharging is not obstructed by reduction of the ultraviolet emission gas, and the color of the visible radiation is stably maintained.Type: GrantFiled: March 30, 1994Date of Patent: September 17, 1996Assignee: Okaya Electric Industries Co., Ltd.Inventors: Fumio Nakajima, Satoshi Watanabe