US2239954A - Cathode for electron discharge tubes - Google Patents

Cathode for electron discharge tubes Download PDF

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Publication number
US2239954A
US2239954A US276795A US27679539A US2239954A US 2239954 A US2239954 A US 2239954A US 276795 A US276795 A US 276795A US 27679539 A US27679539 A US 27679539A US 2239954 A US2239954 A US 2239954A
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United States
Prior art keywords
layer
oxide
cathode
metal
foundation
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Expired - Lifetime
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US276795A
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English (en)
Inventor
Fanselau Werner
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Robert Bosch Fernsehanlagen GmbH
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Fernseh GmbH
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    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01J—ELECTRIC DISCHARGE TUBES OR DISCHARGE LAMPS
    • H01J9/00—Apparatus or processes specially adapted for the manufacture, installation, removal, maintenance of electric discharge tubes, discharge lamps, or parts thereof; Recovery of material from discharge tubes or lamps
    • H01J9/02—Manufacture of electrodes or electrode systems
    • H01J9/04—Manufacture of electrodes or electrode systems of thermionic cathodes
    • H01J9/042—Manufacture, activation of the emissive part
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01J—ELECTRIC DISCHARGE TUBES OR DISCHARGE LAMPS
    • H01J9/00—Apparatus or processes specially adapted for the manufacture, installation, removal, maintenance of electric discharge tubes, discharge lamps, or parts thereof; Recovery of material from discharge tubes or lamps
    • H01J9/02—Manufacture of electrodes or electrode systems
    • H01J9/12—Manufacture of electrodes or electrode systems of photo-emissive cathodes; of secondary-emission electrodes
    • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
    • Y10—TECHNICAL SUBJECTS COVERED BY FORMER USPC
    • Y10S—TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
    • Y10S428/00—Stock material or miscellaneous articles
    • Y10S428/922—Static electricity metal bleed-off metallic stock
    • Y10S428/9335—Product by special process
    • Y10S428/934—Electrical process
    • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
    • Y10—TECHNICAL SUBJECTS COVERED BY FORMER USPC
    • Y10S—TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
    • Y10S428/00—Stock material or miscellaneous articles
    • Y10S428/922—Static electricity metal bleed-off metallic stock
    • Y10S428/9335—Product by special process
    • Y10S428/938—Vapor deposition or gas diffusion
    • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
    • Y10—TECHNICAL SUBJECTS COVERED BY FORMER USPC
    • Y10T—TECHNICAL SUBJECTS COVERED BY FORMER US CLASSIFICATION
    • Y10T428/00—Stock material or miscellaneous articles
    • Y10T428/12—All metal or with adjacent metals
    • Y10T428/12493—Composite; i.e., plural, adjacent, spatially distinct metal components [e.g., layers, joint, etc.]
    • Y10T428/12535—Composite; i.e., plural, adjacent, spatially distinct metal components [e.g., layers, joint, etc.] with additional, spatially distinct nonmetal component
    • Y10T428/12542—More than one such component
    • Y10T428/12549—Adjacent to each other
    • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
    • Y10—TECHNICAL SUBJECTS COVERED BY FORMER USPC
    • Y10T—TECHNICAL SUBJECTS COVERED BY FORMER US CLASSIFICATION
    • Y10T428/00—Stock material or miscellaneous articles
    • Y10T428/12—All metal or with adjacent metals
    • Y10T428/12493—Composite; i.e., plural, adjacent, spatially distinct metal components [e.g., layers, joint, etc.]
    • Y10T428/12535—Composite; i.e., plural, adjacent, spatially distinct metal components [e.g., layers, joint, etc.] with additional, spatially distinct nonmetal component
    • Y10T428/12611—Oxide-containing component
    • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
    • Y10—TECHNICAL SUBJECTS COVERED BY FORMER USPC
    • Y10T—TECHNICAL SUBJECTS COVERED BY FORMER US CLASSIFICATION
    • Y10T428/00—Stock material or miscellaneous articles
    • Y10T428/12—All metal or with adjacent metals
    • Y10T428/12493—Composite; i.e., plural, adjacent, spatially distinct metal components [e.g., layers, joint, etc.]
    • Y10T428/12771—Transition metal-base component
    • Y10T428/12861—Group VIII or IB metal-base component
    • Y10T428/12896—Ag-base component
    • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
    • Y10—TECHNICAL SUBJECTS COVERED BY FORMER USPC
    • Y10T—TECHNICAL SUBJECTS COVERED BY FORMER US CLASSIFICATION
    • Y10T428/00—Stock material or miscellaneous articles
    • Y10T428/12—All metal or with adjacent metals
    • Y10T428/12493—Composite; i.e., plural, adjacent, spatially distinct metal components [e.g., layers, joint, etc.]
    • Y10T428/12771—Transition metal-base component
    • Y10T428/12861—Group VIII or IB metal-base component
    • Y10T428/12903—Cu-base component

Definitions

  • FIG.2 N U 2,239,954 CATHODE FOR ELECTRON DISCHARGE TUBES Filed June 1, 1939 ELECTRON EMISSIVE SURFACE i ik ⁇ saLvER t-ALKALINE METAL coPPER- SlLVER 0x105
  • FIG.2 N U 2,239,954 CATHODE FOR ELECTRON DISCHARGE TUBES Filed June 1, 1939 ELECTRON EMISSIVE SURFACE i ik ⁇ saLvER t-ALKALINE METAL coPPER- SlLVER 0x105
  • My invention relates to a cathode for electron discharge tubes, and particularly to a cathode of the so-called oxide type.
  • Cathodes which consist of a foundation metal, a layer of the oxide of this metal, upon which a suitable metal is deposited. Such cathodes can be produced so as to show good thermionic, photoelectric and secondary emission. As is well known to those skilled in the art, the thickness of the oxide layer is of great importance for obtaining greatest sensitivity and may be difierent for thermionic, photoelectric and secondary. emission.
  • my invention employs a layer of the metal to be oxidized of such predetermined thickness that it will, upon complete oxidation, render an oxide layer of the desired depth.
  • the cathode is produced in the following manner: Upon a surface of a foundation of a suitable metal is deposited a thin layer of a metal which oxidizes only superficially in a glow discharge; upon this latter or intermediate layer is deposited a layer of the metal, the oxide of which is desired, of such a thickness that the desired oxide thickness is obtained after complete oxidation.
  • the active emitting material is then deposited upon the oxide layer in a manner well known to those skilled in the art.
  • a thin layer of copper of a thickness in the order of, say, between 0.5 and 10 microns.
  • the deposit of the copper can be accomplished, for instance, in an electrolytic bath or by evaporation, as may seem preferable.
  • a layer of silver is then deposited by electrolysis or evaporation upon the copper surface, whereby the thickness of the silver deposit can be readily predetermined to a high degree of accuracy by using the proper concentration of the solution, the proper amount of current flow and proper duration of the process in the case of an electrolytic deposit, or' by predetermlning the proper amount of silver in the case of evaporation.
  • the proper values can also be readily determined by experiment.
  • the next step is to oxidize this thin deposit of silver, preferably in a glow discharge in the presence of oxygen.
  • the oxidizing process is not critical 'at all provided only that it secures complete oxidation of the thin silver deposit, because oxidation stops at the copper surface, which oxidizes only superficially.
  • the silver oxide surface is then caesiated in accordance with one of the various methods well known in the art. Such a cathode is shown in cross section in Fig. 1 of the drawing, and the process is illustrated in Fig. 2.
  • cathodes of the oxide type which comprises the steps of providing a surface of a metallic foundation with a coating of a metal which oxidizes only superficially in a gloa discharge in the presence of oxygen, depositing upon said coating a layer of predetermined thickness of a metal, completely oxidizing said lastnamed layer in a glow discharge in the presence of oxygen to convert said layer or metal into a layer of oxide of predetermined thicmess, and all-ralia ing said layer of oxide to produce an electronemissive cathode.
  • cathodes of the oxide type which comprises the steps of providing a surface of a metallic foundation with a coating of a metal which oxidizes only superficially in a glow discharge in the presence of oxygen, depositing upon said coating a layer of predetermined thickness of the same metal as used for said foundation, completely oxidizing said lest-named layer in a glow discharge in the presence of oxygen to convert said layer of metal into a layer of oxide of predetermined thickness, and alkalizing said layer of oxide to produce an electronemissive cathode.
  • cathodes of the oxide type which comprises the steps of providing a surface of a silver foundation with a coating of copper, depositing upon said copper coating a layer of sliver of predetermined thickness, completely oxidizing said last-named silver layerin a glow discharge in the presence of oxygen to convertseid layer of metal into a layer of oxide of predetermined thickness, and alkallzing said layer of oxide to produce an electron-emissive cathode.
  • cathodes of the oxide type which comprises the steps of depositing a layer of metal of predetermined thickness on a surface of a m tallic foundation which oxidizes only superficia ly in a glow discharge in the 20 presenceof oxygen, completely oxidizing said layer

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  • Engineering & Computer Science (AREA)
  • Manufacturing & Machinery (AREA)
  • Solid Thermionic Cathode (AREA)
US276795A 1938-06-01 1939-06-01 Cathode for electron discharge tubes Expired - Lifetime US2239954A (en)

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
DE2239954X 1938-06-01

Publications (1)

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US2239954A true US2239954A (en) 1941-04-29

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US (1) US2239954A (enrdf_load_stackoverflow)
NL (1) NL52419C (enrdf_load_stackoverflow)

Cited By (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US2428289A (en) * 1942-11-07 1947-09-30 Charles Schiffman Electron tube coating
US2944946A (en) * 1955-07-29 1960-07-12 Napier & Son Ltd Catalytic element and method of manufacturing such elements
US3284683A (en) * 1964-06-19 1966-11-08 Packard Bell Electronics Corp Electrical capacitor and methods of forming the capacitor
US3971710A (en) * 1974-11-29 1976-07-27 Ibm Anodized articles and process of preparing same
WO1998026880A1 (en) * 1996-12-19 1998-06-25 Borealis Technical Limited Method and apparatus for thermionic generator

Cited By (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US2428289A (en) * 1942-11-07 1947-09-30 Charles Schiffman Electron tube coating
US2944946A (en) * 1955-07-29 1960-07-12 Napier & Son Ltd Catalytic element and method of manufacturing such elements
US3284683A (en) * 1964-06-19 1966-11-08 Packard Bell Electronics Corp Electrical capacitor and methods of forming the capacitor
US3971710A (en) * 1974-11-29 1976-07-27 Ibm Anodized articles and process of preparing same
WO1998026880A1 (en) * 1996-12-19 1998-06-25 Borealis Technical Limited Method and apparatus for thermionic generator

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Publication number Publication date
NL52419C (enrdf_load_stackoverflow)

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