US3633062A - Direct-heated cathode electrodes with cathode shield for electron guns - Google Patents

Direct-heated cathode electrodes with cathode shield for electron guns Download PDF

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Publication number
US3633062A
US3633062A US827590A US3633062DA US3633062A US 3633062 A US3633062 A US 3633062A US 827590 A US827590 A US 827590A US 3633062D A US3633062D A US 3633062DA US 3633062 A US3633062 A US 3633062A
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United States
Prior art keywords
cathode
heating element
direct
heated
shield
Prior art date
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Expired - Lifetime
Application number
US827590A
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English (en)
Inventor
Mitsuru Tamura
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Noritake Itron Corp
Original Assignee
Ise Electronics Corp
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Publication date
Application filed by Ise Electronics Corp filed Critical Ise Electronics Corp
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    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01J—ELECTRIC DISCHARGE TUBES OR DISCHARGE LAMPS
    • H01J3/00—Details of electron-optical or ion-optical arrangements or of ion traps common to two or more basic types of discharge tubes or lamps
    • H01J3/02—Electron guns
    • H01J3/027—Construction of the gun or parts thereof
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01J—ELECTRIC DISCHARGE TUBES OR DISCHARGE LAMPS
    • H01J1/00—Details of electrodes, of magnetic control means, of screens, or of the mounting or spacing thereof, common to two or more basic types of discharge tubes or lamps
    • H01J1/02—Main electrodes
    • H01J1/13—Solid thermionic cathodes
    • H01J1/15—Cathodes heated directly by an electric current

Definitions

  • U S 313/341 ABSTRACT In a direct-heated cathode electrode for use in 313/346, electron g wherein a heating element is mounted on a base I t C] H0 1/15 to heat a cathode pellet which emits thermoions, a cathode n or 19/08, shield maintained at the same potential as the heating element J is disposed between the same and the base.
  • This invention relates to a novel direct-heated cathode electrode for use in electron guns.
  • the conventional direct-heated cathode electrode for use in electron guns is generally constructed as shown in FIGS. 1 and 2.
  • a heating element 1 is welded to a pair of heater leads 2 and 2 at its opposite ends and the heater leads extend through perforations 4 and 4 through a ceramic base 3 and are secured in position by means of glass beads 5 and 5'.
  • a cathode pellet 6 coated with an oxide is welded to the upper surface of the heating element 1 so that the cathode pellet 6 emits electrons when a suitable voltage is impressed across heater leads 2 and 2', as is well known in the art.
  • the directheated cathode structure fabricated in this manner is then surrounded by a grid cup 7 having an perforation 8 opposing the cathode pellet 6, as shown in FIG. 3.
  • the prior art direct-heated cathode of the type described just above has following disadvantages.
  • Another object off this invention is to provide a novel direct-heated cathode electrode which can improve the heating efficiency of the cathode electrode.
  • a direct-heated cathode electrode comprising an insulator base, a pair of leads extending through the base, a heating element connected between the upper ends of the leads, a cathode pellet coated with an oxide and secured to the heating element, an inverted U-shaped cathode shield mounted upon the base beneath the heating element and between the leads and means to apply the same potential to the cathode shield as the heating element.
  • FIG. 1 is a top plan view of one type of a prior art directheated cathode electrode with a grid electrode removed;
  • FIG. 2 is a sectional view of the cathode electrode shown in FIG. 1 taken along a line II-II;
  • FIG. 3 is a portion of the cross-sectional view shown in FIG. 2 with the grid electrode assembled
  • FIG. 4 shows a top plan view of a direct-heated cathode electrode embodying this invention
  • FIG. 5 is a sectional view of the embodiment shown in FIG. d taken along a line V--V.
  • a generally inverted U shaped cathode shield 9 having a upper surface area larger than that of the cathode pellet 6.
  • the cathode shield 9 is made of a suitable electroconductive material, supported by the ceramic base 3 and one end of the shield is electrically connected to one of the heater leads, e.;g. 2.
  • the cathode shield 9 is maintained at the same potential as the cathode electrode.
  • the cathode shield 9 may be welded to terminals embedded in the ceramic base 3, one of the terminals being connected to one of the leads.
  • the surface of the cathode shield 9 operates to reflect the radiant heat and infrared rays from the heating element back thereto, thus saving the power consumed by the heating element.
  • the im" provement which comprises a cathode shield mounted adjacent said heating element and means to maintain said cathode shield at the same potential as said heater element and cathode pellet.

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  • Electrodes For Cathode-Ray Tubes (AREA)
  • Solid Thermionic Cathode (AREA)
US827590A 1968-05-28 1969-05-26 Direct-heated cathode electrodes with cathode shield for electron guns Expired - Lifetime US3633062A (en)

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
JP1968043526U JPS464029Y1 (en)) 1968-05-28 1968-05-28

Publications (1)

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US3633062A true US3633062A (en) 1972-01-04

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US827590A Expired - Lifetime US3633062A (en) 1968-05-28 1969-05-26 Direct-heated cathode electrodes with cathode shield for electron guns

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US (1) US3633062A (en))
JP (1) JPS464029Y1 (en))
DE (1) DE1926639A1 (en))

Cited By (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3758808A (en) * 1970-07-30 1973-09-11 Licentia Gmbh Dispenser cathode and method for making same
US3783330A (en) * 1971-04-02 1974-01-01 Mitsubishi Electric Corp Direct heated cathode
US3983443A (en) * 1975-03-24 1976-09-28 Rca Corporation Vacuum electron device having directly-heated matrix-cathode-heater assembly
US4298814A (en) * 1978-10-17 1981-11-03 Tokyo Shibaura Denki Kabushiki Kaisha Directly heated type cathode assembly
US4658181A (en) * 1983-10-07 1987-04-14 English Electric Valve Company Limited Travelling wave tubes
US4976643A (en) * 1989-11-02 1990-12-11 Samsung Electron Devices Co., Ltd. Direct-heated cathode structure and method for the fabrication thereof

Citations (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3117249A (en) * 1960-02-16 1964-01-07 Sperry Rand Corp Embedded heater cathode
US3175118A (en) * 1962-05-28 1965-03-23 Gen Electric Low power heater
US3287591A (en) * 1961-12-13 1966-11-22 Sylvania Electric Prod Tantalum carbide incandescent lamp and method of manufacture thereof
US3389290A (en) * 1965-04-06 1968-06-18 Sony Corp Electron gun device

Patent Citations (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3117249A (en) * 1960-02-16 1964-01-07 Sperry Rand Corp Embedded heater cathode
US3287591A (en) * 1961-12-13 1966-11-22 Sylvania Electric Prod Tantalum carbide incandescent lamp and method of manufacture thereof
US3175118A (en) * 1962-05-28 1965-03-23 Gen Electric Low power heater
US3389290A (en) * 1965-04-06 1968-06-18 Sony Corp Electron gun device

Cited By (7)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3758808A (en) * 1970-07-30 1973-09-11 Licentia Gmbh Dispenser cathode and method for making same
US3783330A (en) * 1971-04-02 1974-01-01 Mitsubishi Electric Corp Direct heated cathode
US3983443A (en) * 1975-03-24 1976-09-28 Rca Corporation Vacuum electron device having directly-heated matrix-cathode-heater assembly
FR2305848A1 (fr) * 1975-03-24 1976-10-22 Rca Corp Dispositif electronique a vide a ensemble filament-cathode a reserve a chauffage direct
US4298814A (en) * 1978-10-17 1981-11-03 Tokyo Shibaura Denki Kabushiki Kaisha Directly heated type cathode assembly
US4658181A (en) * 1983-10-07 1987-04-14 English Electric Valve Company Limited Travelling wave tubes
US4976643A (en) * 1989-11-02 1990-12-11 Samsung Electron Devices Co., Ltd. Direct-heated cathode structure and method for the fabrication thereof

Also Published As

Publication number Publication date
DE1926639A1 (de) 1970-01-02
JPS464029Y1 (en)) 1971-02-12

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