Plural Separate Cathode Sections Patents (Class 313/338)
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Patent number: 8767371Abstract: An ignition apparatus is provided with an ignition plug (101) including a first electrode (101a) that generates a high voltage by means of energy supplied by an ignition coil device (102), a second electrode (101b) that faces the first electrode (101a) through a first gap and causes in the first gap a spark discharge for igniting a fuel, and a third electrode (101c) that faces the first electrode through a second gap that is smaller than the first gap, and is connected with the second electrode (101b) by way of an electric conductor (302) having a predetermined resistance value; a control apparatus drives the ignition coil device (102) twice or more times in a single ignition process so that the ignition plug causes a spark discharge.Type: GrantFiled: June 11, 2012Date of Patent: July 1, 2014Assignee: Mitsubishi Electric CorporationInventor: Kimihiko Tanaya
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Patent number: 8324590Abstract: A chopper for a particle beam comprises an annular guiding element and an element for controlling the intensity of the particle beam. The control element is supported on the guiding element so that at least one point under consideration on the control element can revolve along the circumference of the guiding element. Mounting along a circumference allows for accommodation of considerably higher disturbance torque than mounting on a rotational axle, using the same bearing force. Furthermore, it is possible to dispense with the entire rotational axle, and the control element can be designed, for example, as a ring. This brings about considerable weight savings as compared to chopper wheels according to the prior art, which accordingly enables higher circumferential speeds and therefore higher modulation frequencies for the particle beam, while at the same time increasing operational safety.Type: GrantFiled: September 12, 2008Date of Patent: December 4, 2012Assignee: Forschungszentrum Juelich GmbHInventors: Walter Renftle, Hans Kaemmerling, Michael Prager, Magdalena Prager, legal representative
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Patent number: 8000449Abstract: It is described an emitter (26, 40) for X-ray tubes comprising: a flat foil with an emitting section (30, 46); and at least two electrically conductive fixing sections (31-34; 41-44); wherein the emitting section (30, 46) is unstructured.Type: GrantFiled: October 10, 2007Date of Patent: August 16, 2011Assignee: Koninklijke Philips Electronics N.V.Inventors: Stefan Hauttmann, Wolfram Maring
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Patent number: 7855373Abstract: An electron gun (1) includes an emitter (2), a tubular support (3) and an adaptor (4) for receiving the emitter. The adaptor includes a tapered plugging surface (7) and the tubular support includes a correspondingly tapered seating surface (9) for receiving the plugging surface. The plugging surface and seating surface have conical profiles which help to position the adaptor concentrically with the support.Type: GrantFiled: May 13, 2005Date of Patent: December 21, 2010Assignee: Nanobeam LimitedInventor: Tao Zhang
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Patent number: 7781951Abstract: To provide a filament lamp having a plurality of filaments disposed in sequence in the axial direction of a light-emitting lamp tube which is configured so as not to shield emitted light from a center filament, internal leads for two filaments disposed proximate hermetically sealed parts at both ends are connected to metal foils in the same hermetically sealed part.Type: GrantFiled: March 12, 2009Date of Patent: August 24, 2010Assignee: Ushiodenki Kabushiki KaishaInventors: Kenji Tanino, Shinji Taniguchi, Yukio Ueshima
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Patent number: 7079093Abstract: An organic light emitting diodes display device includes a number of data lines, scan lines, and cathode electrodes. These scan lines are perpendicular to the data lines to form a number of pixels, each of which possess a pixel area respectively. All the pixels areas form a pixel area array. These cathode electrodes are parallel to the scan lines or data lines and partially cover the pixel area array. Spaces between each two cathode electrodes are above the scan lines or data lines to avoid the parasitic capacitance between the cathode electrodes and scan lines or data lines. And thus the resistance capacitance time delay is prevented.Type: GrantFiled: April 17, 2003Date of Patent: July 18, 2006Assignee: Au Optronics Corp.Inventor: Wein-Town Sun
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Patent number: 6917147Abstract: A triode type cathode structure including a cathode assembly composed of a cathode electrode at least one electron emitter and a resistive layer inserted between the cathode electrode and the at least one electron emitter to connect them together electrically. The triode cathode structure also includes a grid electrode separated from the cathode assembly by a layer of electrical insulation. The cathode electrode is arranged in a first plane and the at least one electron emitter is arranged in a second plane parallel to the first plane and the cathode electrode and each electron emitter are separated by a same distance measured in a third plane parallel to the first and second planes.Type: GrantFiled: February 19, 2003Date of Patent: July 12, 2005Assignee: Commissariat a l'Energie AtomiqueInventors: Jean Dijon, Adeline Fournier, Brigitte Montmayeul, Aimé Perrin
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Publication number: 20040183423Abstract: The indirectly heated cathode structure includes a base metal having a thermal electron emitting material layer, a cylindrical sleeve holding the base metal at one end portion thereof and housing a heating heater in the inside thereof, an support having a large-diameter portion and g a small-diameter portion, and a cathode disc having a large-diameter portion at the leg-portion-side of the heating heater and having a small-diameter portion at the heater-main-portion side of the heating heater, wherein an outer surface of another end portion of the sleeve and an inner surface of the small-diameter portion of the support are fixed to each other, and an outer surface of the large-diameter portion of the support and an inner surface of the small-diameter portion of the cathode disc are fixed to each other.Type: ApplicationFiled: March 4, 2004Publication date: September 23, 2004Inventors: Yukio Suzuki, Sachio Koizumi, Toshifumi Komiya
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Patent number: 6664545Abstract: Bradbury-Nielson gates for the modulation of beams of charged particles, particularly ion beams in mass spectrometry, have been produced with an adjustable wire spacing down to 0.075 mm or a smaller spacing. The gates are robust, they can be fabricated in less than 3 hours, and the method of production is reproducible. In time-of-flight mass spectrometers, fine wire spacing leads to improvements in mass resolution and modulation rates. Gates that were produced using this new method have been installed in a Hadamard transform time-of-flight mass spectrometer in order to demonstrate their utility.Type: GrantFiled: August 28, 2002Date of Patent: December 16, 2003Assignee: The Board of Trustees of the Leland Stanford Junior UniversityInventors: Joel R. Kimmel, Friedrich Engelke, Richard N. Zare
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Publication number: 20030168965Abstract: The present invention provides a display device which can sufficiently ensure spaces for mounting distance holding members 5 when the distance holding members 5 are mounted, can facilitate the assembling and can realize the electron emission characteristics of high performance. At least two different types of gaps b, c (b <c) are provided among cathode lines 2 (2R, 2G, 2B) and the distance holding members 5 are mounted at portions of the gaps c having a larger size whereby the space for mounting the distance holding members 5 can be sufficiently ensured.Type: ApplicationFiled: January 6, 2003Publication date: September 11, 2003Inventors: Yuuichi Kijima, Kenji Miyata, Yoshiyuki Kaneko, Shigemi Hirasawa, Susumu Sasaki, Hiroshi Kawasaki, Jun Ishikawa
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Patent number: 6252341Abstract: An impregnated cathode and a method of manufacturing the same are provided for suppressing emission of unwanted electrons and particles generated from an excess electron emitting substance so as to achieve a steady electron emission characteristic. The impregnated cathode is placed directly beneath an electron emission hole of a first grid. The impregnated cathode is made up of a first sintered porous element whose surface functions as an electron emitting region and a second sintered porous element whose surface is a peripheral region other than the electron emitting region. The porosity of the first sintered porous element is greater than that of the second sintered porous element. Not only the first sintered porous element having the electron emitting region but also the second sintered porous element corresponding to the region around the electron emitting region is impregnated with the electron emitting substance.Type: GrantFiled: November 2, 1998Date of Patent: June 26, 2001Assignees: Sony Corporation, Citizen Watch Co., Ltd, Cimeo Precision Co., Ltd.Inventors: Yoji Hasegawa, Shinji Ogawa, Daichi Imabayashi, Makoto Furukawa, Nobuyuki Yoshino, Junji Sato, Yoshirou Hirai, Naoto Ogasawara, Kuniyasu Kobayashi
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Patent number: 6184613Abstract: An electrode assembly including a first cathode member provided with a hole enclosed by a frame portion. The frame portion surrounding the hole has a contact surface that comes into contact with an object to be plated at one of its surfaces, and an insulating member is provided with holes and enclosed by a frame portion, with one surface of the frame portion placed on top of another surface of the frame portion of the first cathode member. A second cathode member also provided with a hole enclosed by a frame portion, with one surface of the frame portion placed on top of one surface of the other frame portion of the insulating member. The smallest bore diameter at the hole of the second cathode member is larger than the smallest bore diameter at the holes and of the insulating member.Type: GrantFiled: September 14, 1998Date of Patent: February 6, 2001Assignee: TDK CorporationInventors: Satoshi Inoue, Toyoaki Tanaka
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Patent number: 6181057Abstract: An electrode assembly, including a cathode member is provided with a hole enclosed by a frame portion and a contact surface that comes into contact with an object to be plated at one surface of the frame portion. The cathode member include a conductive material such as copper plate. The cathode member is provided with a lead conductor. An insulating member is provided with holes and enclosed by frame portions, with the frame portions and placed on another surface of the frame portion of the cathode member. The frame portion of the first insulating member covers the internal circumferential edge of the cathode member over a width W1.Type: GrantFiled: September 14, 1998Date of Patent: January 30, 2001Assignee: TDK CorporationInventors: Satoshi Inoue, Toyoaki Tanaka
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Patent number: 5864201Abstract: Electron-optical device having two elongate emitting regions arranged symmetrically with respect to a longitudinal axis for producing two electron beams having an elongate cross-section. By means of electron grids, the two beams are focused at the same point of an electron target arranged transversely to the longitudinal axis and having a short central axis and a long central axis. The elongate emitting regions have their smallest cross-section parallel to the scanning direction of a device, cooperating with the electron-optical device, for scanning a target arranged transversely to the longitudinal axis.Type: GrantFiled: September 4, 1996Date of Patent: January 26, 1999Assignee: U.S. Philips CorporationInventors: Frederik C. Gehring, Tom Van Zutphen, Albert Manenschijn
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Patent number: 5412281Abstract: A crossed-field amplifier (CFA) includes a cylindrical cathode having an emitting surface coaxially disposed within an annular anode structure. The cathode has at least one circumferential groove disposed in the emitting surface. The grooves are relatively deep in comparison with their width. The grooves provide a phase smoothing of the rotating electron cloud spokes operative during crossed-field interaction. CFA noise is reduced by removal of the out-of-phase electrons. Due to their deeply cycloiding paths, these out-of-phase electrons become trapped in the grooves within a region generally shielded from the electric field of the CFA.Type: GrantFiled: March 31, 1993Date of Patent: May 2, 1995Assignee: Litton Systems, Inc.Inventors: George K. Farney, Chris L. Wheeland, Kenneth F. Ramacher, Edward M. Doyle, Michael S. Worthington
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Patent number: 5280218Abstract: A cathode of a crossed field device includes a first electrode and a second electrode disposed about and dielectrically spaced from the first electrode. In a preferred embodiment the electrode comprises a pair of electrodes, a first one of the pair being a masking electrode disposed about and dielectrically spaced from the first electrode and a second one of the pair being an emitter electrode disposed about and dielectrically spaced from the masking electrode.Type: GrantFiled: September 24, 1991Date of Patent: January 18, 1994Assignee: Raytheon CompanyInventor: Burton H. Smith
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Patent number: 5134343Abstract: For the purpose of generating an electron beam (5), a quasi-optical gyrotron comprises an electron-beam gun (1) with an annular cathode (2). The electron beam (5) passes along an electron beam axis (6) and in so doing is compressed by a static magnetic field and forced into gyration, so that it excites in a quasi-optical resonator a standing alternating electromagnetic field of specific wavelength. The resonator exhibits two mirrors (9a, 9b) arranged opposite to one another on a resonator axis (8) aligned perpendicular to the electron beam axis (6). In order to increase the efficiency of the gyrotron, the annular cathode (2) alternately exhibits segments of high and low emitting power such that the electron beam (5) has an azimuthally varying current density, values of low current density in the resonator coinciding spatially with nodal surfaces of the standing alternating electromagnetic field.Type: GrantFiled: August 22, 1990Date of Patent: July 28, 1992Assignee: Asea Brown Boveri Ltd.Inventor: Hans-Gunter Mathews
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Patent number: 5099170Abstract: Three pipes for supporting three cathodes of an electron gun for an in-line type color cathode-ray tube parallel with one another in one and the same plane are arranged in one and the same plane, peripheral portions of the pipes are surrounded by a laterally extending cylindrical outer supporting frame extended in an arranging direction of the pipes through a fixing agent formed of crystallized hard glass powder with low melting point to fix the pipes, and a trapizoidal notch is provided upwardly of a lower side of the cylindrical outer supporting frame and along axes of the pipes to thereby prevent the pipes from being deformed.Type: GrantFiled: September 6, 1990Date of Patent: March 24, 1992Assignee: Hitachi, Ltd.Inventor: Sachio Koizumi
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Patent number: 5045749Abstract: An electron beam generator which can operate in pulse or continuous mode, has an electron beam which is emitted in a main electron gun including a thermionic cathode and an anode. Used in association with this main electron gun is an auxiliary electron gun including a cathode, a grid intended to modulate an auxiliary electron beam in pulses when it is operating in pulse mode or to adjust the current of the auxiliary electron beam when it is operating in continuous mode, and an anode. The anode is in thermal and electric contact with the cathode of the main electron gun. The auxiliary electron beam controls the emission from the cathode. The electron beam emitted by the main electron gun is not disturbed by crossing the grid. Application of the electron beam generator is notably to microwave longitudinal interaction tubes operating at high average and/or peak power.Type: GrantFiled: March 1, 1990Date of Patent: September 3, 1991Assignee: Thomson Tubes ElectroniquesInventor: Henri Desmur
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Patent number: 4994709Abstract: A very fine-mesh, non-emissive shadow grid is formed on the smooth emissive surface 16 of a thermionic cathode 12 by deposition from a vapor a continuous layer 22 of non-emissive conductive material. Between the elements 24 of the grid the non-emissive material is removed by bombardment through an apertured mask to restore emissivity between the elevated grid elements 24.Type: GrantFiled: March 22, 1989Date of Patent: February 19, 1991Assignee: Varian Associates, Inc.Inventors: Michael C. Green, George V. Miram
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Patent number: 4954745Abstract: A dispenser cathode body includes a heat capturing portion extending rearwardly from the dispenser cathode, said heat capturing portion having greater mass and thickness than an exterior support skirt. A slip-in heater is received within the heat capturing portion. Substantially greater electron emission density is secured without requiring injuriously high temperatures from the slip-in heater.Type: GrantFiled: March 22, 1989Date of Patent: September 4, 1990Assignee: Tektronix, Inc.Inventor: Bernard K. Vancil
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Patent number: 4931684Abstract: A device is provided for detecting defects in wire or cable insulation which is located in a vacuum without disconnecting the cable by synchronously detecting the current in a sense conductor with respect to the potential waveform existing or imposed on the cable under test. A sense conductor and a scanned extended electron source having a linear cathode array are both placed in close proximity to and along the cable under test. Only a small portion of the cathodes in the linear array are excited at any one time and by placing the proper signals on the excitation conductors of the electron source, the electron generation scans or propagates along the entire length of the extended electron source. The current flowing in the sense conductor due to the electrons from the electron source varies depending upon the presence of defects in the cable insulation.Type: GrantFiled: December 23, 1988Date of Patent: June 5, 1990Assignee: Westinghouse Electric Corp.Inventors: Juris A. Asars, Michael E. Colbaugh
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Patent number: 4928034Abstract: According to the present invention, an impregnated cathode is provided wherein an alloy layer of iridium and tungsten is formed on a surface of a porous pellet impregnated with an oxide of an alkali earth metal, wherein a crystal structure of the alloy has an .epsilon.II phase comprising an hcp structure whose lattice constants a and c satisfy 2.76.ltoreq.a.ltoreq.2.78 and 4.44.ltoreq.c.ltoreq.4.46, respectively. The impregnated cathode of the present invention maintains stable electron emission characteristics from an early stage of operation.Type: GrantFiled: November 18, 1988Date of Patent: May 22, 1990Assignee: Kabushiki Kaisha ToshibaInventors: Sakae Kimura, Masaru Nikaido, Katumi Yanagibashi, Katsuhisa Homma, Yoshiaki Ouchi
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Patent number: 4686413Abstract: A method of manufacturing a cathode for magnetron comprises a cathode sleeve formed as a hollow cylinder, a heater inside the sleeve, two end shields formed around the sleeve at a prescribed interval and an electron emitting material applied around the sleeve between both end-shields, wherein a plurality of isolated projections are almost regularly and intergraly formed around the sleeve between the end-shields, and the above electron emitting material is applied onto the cathode sleeve to fill gaps among the plural projections.According to the method of manufacturing a cathode of the present invention, the efficiency of electron emission and electric conductivity are not lowered, whereby the stable operation can be realized for a long term.Type: GrantFiled: December 17, 1986Date of Patent: August 11, 1987Assignee: New Japan Radio Co., Ltd.Inventors: Yoshihiko Sato, Nobuaki Yamamoto
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Patent number: 4680500Abstract: The structure is material such as a ceramic in the form of a bundle of open cells, a "honeycomb", with the shape of the cells corresponding to the shape of the openings desired in the grid. The cathode is formed in the cells, rather than adding the grid to a ready-made cathode. The grid is formed by coating the end of the cell walls with a conducting material (metal and/or carbon). The surface of the cathode is suitably recessed from the grid.Type: GrantFiled: March 6, 1986Date of Patent: July 14, 1987Assignee: The United States of America as represented by the Secretary of the Air ForceInventor: Erik S. Buck
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Patent number: 4524297Abstract: A cathode having a layer structure in which alternate layers consisting essentially of emitter material (2) and base material (1) are provided at an oblique angle to the cathodes's macroscopic emitting surface. In a preferred embodiment the surface has a microscopically stepped structure formed by ends of the base material layers and portions of the emitter material layers coating the ends. In an alternative embodiment the surface is not stepped but is formed by a polycrystalline or a preferentially oriented polycrystalline coating layer which is provided on the succession of beveled layers. The succession of layers is manufactured by alternating depositions from the gaseous phase and by subsequent bevel grinding of the layers. The polycrystalline coating layer is provided by deposition from the gaseous phase. The stepped surface is formed, for example, by selective structure etching after the bevel grind.Type: GrantFiled: September 13, 1982Date of Patent: June 18, 1985Assignee: U.S. Philips CorporationInventor: Georg Gartner
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Patent number: 4489254Abstract: Disclosed is a magnetron for a microwave oven which has a drain electrode (60) near a cathode (25) and in a position where an electron beam path is not interfered with. The cathode and the drain electrode are formed in spiral shapes. Turns of the cathode are alternately arranged with those of the drain electrode. When the magnetron is operated, the drain electrode is kept at the same potential as the cathode or is kept at a negative potential relative to that of the cathode. Therefore, positive ions in the vicinity of the cathode are collected at the drain electrode, thus decreasing high frequency noise.Type: GrantFiled: May 19, 1982Date of Patent: December 18, 1984Assignees: Tokyo Shibaura Denki Kabushiki Kaisha, Nippon Hoso KyokaiInventors: Tokuju Koinuma, Norio Tashiro, Kaizo Yamamoto
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Patent number: 4380717Abstract: A magnetron consists of a cathode structure mounted within an anode cavity arrangement. In order to prolong the operational life of the cathode structure electron emissive material is located within recesses formed in the outer surface of a cylindrical support. As the electron emissive material erodes away during operation of the magnetron its surface area remains substantially unreduced.Type: GrantFiled: September 11, 1981Date of Patent: April 19, 1983Assignee: English Electric Valve Company LimitedInventor: Alan H. Pickering
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Patent number: 4373144Abstract: In an exemplary embodiment, a cathode cup for electron focusing has a groove-like cavity for the heater coil. The cathode cup is subdivided, approximately perpendicularly to the longitudinal direction of the heater coil into several parts which are insulated from one another, to which separate control potentials can be supplied.Type: GrantFiled: December 17, 1980Date of Patent: February 8, 1983Assignee: Siemens AktiengesellschaftInventor: Kurt Franke
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Patent number: 4359666Abstract: A new method of fabricating a cylindrical segmented cathode by bending a photoetched bar-band to form a cylindrically-shaped cage and slipping it over a cylindrical electron emissive surface which will tightly fit inside the cage when the cathode is raised to its normal temperature. The bars of the band provide nonemissive segments of the cathode surface.Type: GrantFiled: July 21, 1980Date of Patent: November 16, 1982Assignee: Varian Associates, Inc.Inventor: Robert N. Tornoe
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Patent number: 4302702Abstract: The invention relates to metal oxide activated porous tungsten cathodes and methods of their manufacture. A cathode 1 of porous tungsten activated by metal oxides is mounted on a housing 2 which has a heating filament 3. On the outer face of the cathode there is a pattern or grid of pure tungsten (preferably formed by a chemical vapor deposition of WCl.sub.6 or WF.sub.6) of crystalline material the outer face of which has an orientation in the (100) or (110) plane and is parallel to the surface of the cathode. The invention will find particular use in the cathode guns of high frequency tubes such as traveling wave tubes and klystrons.Type: GrantFiled: May 9, 1978Date of Patent: November 24, 1981Assignee: Thomson-CSFInventors: Jean Montgaillard, Arvind Shroff
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Patent number: 4121130Abstract: An insulating substrate is provided with a plurality of discrete electrode pads on a surface thereof. A thermionic line cathode, e.g., a directly heated filament, is positioned to one side of the substrate surface and extends across a surface of each one of the electrode pads. An apertured electrode is positioned in spaced relation to the cathode in a direction away from the surfaces of the electrode pads. The apertured electrode may include a single slit-shaped aperture or a plurality of colinear apertures. The structure may also include a pair of spaced parallel filter plates whose surfaces are disposed in parallel relation to the longitudinal axis of the line cathode and in orthogonal relation to the surfaces of the electrode pads. The filter plates function to collimate the electron flow emitted from the cathode.Type: GrantFiled: April 4, 1977Date of Patent: October 17, 1978Assignee: RCA CorporationInventor: Robert Allen Gange
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Patent number: 4093893Abstract: A short arc fluorescent lamp comprises an envelope having dimensions compatible with existing incandescent lamp luminaires. A radio frequency power supply, enclosed within the lamp base structure, reduces anode voltage drop to increase lamp efficacy. Cathode voltage drop and sputtering are reduced by compact hollow cathode assemblies, including centrally disposed filaments, which are positioned at opposite ends of a tubular envelope assembly having a large ratio of diameter to length. Diffuse cathode emission allows operation with low pressure, low atomic weight fill gas which further increases luminous efficiency.Type: GrantFiled: November 22, 1976Date of Patent: June 6, 1978Assignee: General Electric CompanyInventor: John M. Anderson
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Patent number: 4031425Abstract: A dispenser cathode for a grid-controlled electron tube in which the emission of surface regions immediately opposite the control grid is reduced by providing projections above the emissive surface of fused, pore-closing portons which have a focussing effect. These projections may be formed by electron beam or laser beam welding.Type: GrantFiled: October 2, 1975Date of Patent: June 21, 1977Assignee: U.S. Philips CorporationInventors: Reinhard Ziegler, Horst Seifert
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Patent number: 4020381Abstract: A flat cathode ray tube device is provided for display of information by response to an electron beam of a phosphor coating on a face plate. A monolithic structure includes an x-y matrix of electron source cathodes and a pair of grid arrays successively spaced from the matrix with holes therethrough adjacent to and aligned with the cathodes selectively to form and individually control the intensity of an electron beam from each of said cathodes. Deflection control structure has holes through which the beams may pass with a set of x-y deflection electrodes associated with each of the holes for x-y control of the trajectory of each of the beams. A support plate forms the base of the monolithic structure with the cathodes mounted thereon and a face plate structure marginally sealed to the support plate provides a vacuum tight envelope housing the monolithic structure.Type: GrantFiled: January 15, 1976Date of Patent: April 26, 1977Assignee: Texas Instruments IncorporatedInventors: Frederick G. Oess, Michael Peshock, Jr.
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Patent number: 3978364Abstract: High efficiency, multi-dimensional thin film vacuum tubes suitable for use in high temperature, high radiation environments are described. The tubes are fabricated by placing, as by photolithographic techniques, such as are used in solid state integrated circuits, thin film electrode members in selected arrays on facing interior wall surfaces of an alumina substrate envelope. Cathode members are formed using thin films of triple carbonate. The photoresist used in photolithography aids in activation of the cathodes by carbonizing and reacting with the reduced carbonates when heated in vacuum during forming. The finely powdered triple carbonate is mixed with the photoresist used to delineate the cathode locations in the conventional solid state photolithographic manner. Upon high temperature forming (1000.degree. C) the barium, etc. is formed at the surface. Anode and grid members are formed using thin films of refractory metal.Type: GrantFiled: July 24, 1974Date of Patent: August 31, 1976Assignee: The United States of America as represented by the Administrator of the National Aeronautics and Space AdministrationInventors: John Dimeff, William J. Kerwin
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Patent number: 3967150Abstract: 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.Type: GrantFiled: January 31, 1975Date of Patent: June 29, 1976Assignee: Varian AssociatesInventors: Erling L. Lien, George V. Miram, Richard B. Nelson