US3491232A - High vacuum discharge tube for high voltages - Google Patents

High vacuum discharge tube for high voltages Download PDF

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Publication number
US3491232A
US3491232A US662598A US3491232DA US3491232A US 3491232 A US3491232 A US 3491232A US 662598 A US662598 A US 662598A US 3491232D A US3491232D A US 3491232DA US 3491232 A US3491232 A US 3491232A
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US
United States
Prior art keywords
anode
cathode
screening
tube
cylinder
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
Application number
US662598A
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English (en)
Inventor
Kurt Franke
Kurt Hirsch
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.)
US Philips Corp
Original Assignee
US Philips Corp
Priority date (The priority date 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 date listed.)
Filing date
Publication date
Application filed by US Philips Corp filed Critical US Philips Corp
Application granted granted Critical
Publication of US3491232A publication Critical patent/US3491232A/en
Anticipated expiration legal-status Critical
Expired - Lifetime legal-status Critical Current

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Classifications

    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01J—ELECTRIC DISCHARGE TUBES OR DISCHARGE LAMPS
    • H01J5/00—Details relating to vessels or to leading-in conductors common to two or more basic types of discharge tubes or lamps
    • H01J5/02—Vessels; Containers; Shields associated therewith; Vacuum locks
    • H01J5/06—Vessels or containers specially adapted for operation at high tension, e.g. by improved potential distribution over surface of vessel
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01J—ELECTRIC DISCHARGE TUBES OR DISCHARGE LAMPS
    • H01J19/00—Details of vacuum tubes of the types covered by group H01J21/00
    • H01J19/28—Non-electron-emitting electrodes; Screens
    • H01J19/40—Screens for shielding

Definitions

  • the invention relates to a high vacuum discharge tube for high voltages comprising an anode cylinder having at least one open end and inside the cylinder an anode surface arranged perpendicular to the cylinder axis and furthermore comprising a cathode placed outside the cylinder and being surrounded by screening means, said screening means having an opening provided with screening surfaces, and located at some distance opposite the open end of the anode cylinder.
  • Such discharge tubes have a cathode or electron emitting filament placed inside a generally cylindrical anode.
  • the known screening means are not suitable for high vacuum discharge tubes for high voltages as these tubes are exposed to temperatures which require screening means of a particular type. With the known means an effective screening cannot be realized.
  • screening means which surround a cylindrical anode at such a distance, that the anode surfaces exposed to electron bombardment are situated inside the screening cup.
  • These screening means are intended to prevent charged carriers escaping from the active discharge space and thus can no longer reach the wall of the vessel which otherwise would cause in the long run a brownish discoloring of the glass.
  • ballast tubes as presently available also show this brownish discoloring.
  • These ballast tubes are used in color television receivers in which they are connected in parallel with the colour picture tube in order to keep constant the sum of the currents through the picture tube and the ballast tube. This is an essential function as otherwise the colors will not be reproduced correctly.
  • the ballast tubes are triodes, which show as soon as they are switched on fluorescence of the glass wall which disappears when the tube has been in operation for a longer time and then changes into a brownish discoloring of the glass. It appears that the discoloring results from a decomposition of the lead oxide contained in the glass. The higher the operating voltage of the tube,
  • the anode surfaces of these high vacuum discharge tubes for high voltages are situated inside an anode cylinder such that the anode surfaces, viewed in the direction of the electron stream, lie deep in the cylinder.
  • the problem underlying the invention was first of all to establish the physical phenomena leading to the brownish discoloring of the glass of the ballast tubes.
  • a radio-active radiation is set free by the electron bombardment of the anode surface situated deep in the anode cylinder.
  • the screening means may consist of a cup fixed to the cathode screening means and provided with a current supply lead, said cup surrounding the anode cylinder up to a certain height and also surrounding the space between the cylinder and the screening surfaces.
  • the cup itself may be provided with a supply lead leading to the outside of the tube.
  • the cup may be electrically connected to the cathode screening means which results in a simpler construction.
  • a metal ring adjacent to the tube wall, and to provide the ring with supply lead leading to the outside of the tube.
  • this metal ring is fixed to the cathode screening means and is electrically connected thereto.
  • FIGURE 1 shows, partly in a cross-sectional view, a ballast tube for color television receivers provided with a screening cup according to the invention.
  • FIGURE 2 shows likewise a ballast tube for colour television receivers provided with a metal screening ring according to the invention.
  • FIGURES 1 and 2 the glass vessel of the tube is designated by the numeral 1.
  • An anode cap 2 fused in the glass wall and projecting from the outside of the tube, carries an anode-cylinder 5 by means of a support 3 and supporting rods 4. Inside this anode cylinder and perpendicular to its axis is situated a cup shaped body 6 having an anode surface 7.
  • a cathode 8 At the bottom of the .tube and standing thereon is arranged a cathode 8 surrounded by a grid 9; both are placed inside a cathode screen 10.
  • the screen 10 has an opening 11 through which the electrons emitted by the cathode 8 after having passed the grid '9 can proceed to the anode cylinder 5. These electrons are accelerated by a voltage of about 25,000 volts applied between the anode cylinder and the cathode 8 and hit at a very high speed the anode surface 7. This electron bombardment sets free a radioactive radiation which is emitted in the direction to the cathode.
  • This radiation indicated by the dotted line 12 reaches the surface 13 of the cathode screen and there sets free photoelectrons which leave the surface for instance as indicated by the dotted line 14.
  • the photoelectrons would reach the glass wall 1 unhindered.
  • a screening cup 15 such that the electrons 14 set free by the radioactive radiation travel in the direction of the dotted line 16, that is to say in the direction to the anode and consequently are prevented from reaching the glass wall.
  • the lifetime of ballast tubes provided with such a screening cup is substantially longer than the lifetime of the tubes hitherto known.
  • Plates 17 are arranged in order to reflect heat radiation. Furthermore the tube is provided with contact-pins 18.
  • metal ring 19 adjacent the tube wall 1 is used instead of the screening cup.
  • the ring is connected by means of a lead 20 to the cathode screen 10 and also to the cathode 8 such that both the ring and the screen 15 modify the course of the equipotential lines, thereby forcing the photoelectrons to turn back and preventing them from traveling to the glass wall.
  • a high vacuum discharge tube for high voltages comprising an evacuated envelope and within said envelope an anode cylinder having at least one open end and inside the cylinder an anode surface arranged perpendicular to the cylinder axis a cathode placed outside the cylinder, screening means surrounding the oathodes, said cathode screening means having an opening provided with screening surfaces and located spaced from and opposite the open end of the anode cylinder, additional screening means surrounding the open end of said anode between said envelope and said cathode screening means for intercepting photoelectrons liberated at the said 4 screening surfaces by radioactive radiation emanating from the anode surface and produced by electron bombardment of that surface situated within the anode cylinder, and means to apply a potential to said latter screening means for returning the photoelectrons to the anode cylinder.
  • a high vacuum discharge tube comprising a cup fixed to the cathode screening means and provided with a current supply lead, said cup surrounding the anode cylinder up to a certain height and also surrounding the space between the cylinder and the screening surfaces.
  • a high vacuum discharge tube according to claim 1 wherein the additional screening means comprise a metal ring adjacent the tube wall, said ring being provided with a current supply lead.
  • a high vacuum discharge tube according to claim 4, wherein the metal ring is fixed to the cathode screening means and is electrically connected thereto.
  • a high vacuum discharge tube according to claim 1 wherein the additional cathode screening means are electrically connected to the cathode.

Landscapes

  • Electron Tubes For Measurement (AREA)
  • Discharge Lamps And Accessories Thereof (AREA)
  • Vessels, Lead-In Wires, Accessory Apparatuses For Cathode-Ray Tubes (AREA)
US662598A 1966-08-27 1967-08-23 High vacuum discharge tube for high voltages Expired - Lifetime US3491232A (en)

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
DEP0040278 1966-08-27

Publications (1)

Publication Number Publication Date
US3491232A true US3491232A (en) 1970-01-20

Family

ID=7377041

Family Applications (1)

Application Number Title Priority Date Filing Date
US662598A Expired - Lifetime US3491232A (en) 1966-08-27 1967-08-23 High vacuum discharge tube for high voltages

Country Status (5)

Country Link
US (1) US3491232A (de)
CH (1) CH470751A (de)
DE (1) DE1564506B1 (de)
GB (1) GB1192970A (de)
NL (1) NL6711517A (de)

Citations (7)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US2040883A (en) * 1935-05-29 1936-05-19 Solomon Guillermo Electronic tube
US2464270A (en) * 1946-03-15 1949-03-15 Raytheon Mfg Co Shield connection for external press type electron discharge tubes
FR1106979A (fr) * 1953-08-31 1955-12-27 Philips Nv Diode à vide poussé pour tensions élevées
US2888590A (en) * 1954-09-13 1959-05-26 Gen Electric Electronic tube structure
US2933633A (en) * 1955-02-16 1960-04-19 Gen Electric Electric discharge device
US3041494A (en) * 1959-03-25 1962-06-26 Rca Corp High voltage rectifier tube
US3231778A (en) * 1963-06-20 1966-01-25 Sylvania Electric Prod Signal barrier

Family Cites Families (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
DE1220524B (de) * 1965-01-18 1966-07-07 Rca Corp Elektronenentladungsroehre mit Glasteilen, die der Gefahr der Zersetzung unterliegen
DE342909C (de) * 1916-06-11 1921-10-25 Siemens Schuckertwerke G M B H Hochspannungsvakuumapparat fuer Starkstrombetrieb
US2256330A (en) * 1940-06-29 1941-09-16 Rca Corp High voltage rectifier
DE891117C (de) * 1951-10-14 1953-09-24 Siemens Reiniger Werke Ag Elektrische Entladungsroehre, insbesondere Ventilrohr mit einer die Kathode topffoermig umgebenden Anode
DE937540C (de) * 1952-04-09 1956-01-12 Licentia Gmbh Hochvakuum-Gleichrichterroehre fuer hohe und hoechste Spannungen
DE1723625U (de) * 1954-08-27 1956-06-07 Philips Nv Hochvakuumdiode fuer hohe spannungen mit einem glaskolben, einer zylindrischen anode und einer oxydkathode.

Patent Citations (7)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US2040883A (en) * 1935-05-29 1936-05-19 Solomon Guillermo Electronic tube
US2464270A (en) * 1946-03-15 1949-03-15 Raytheon Mfg Co Shield connection for external press type electron discharge tubes
FR1106979A (fr) * 1953-08-31 1955-12-27 Philips Nv Diode à vide poussé pour tensions élevées
US2888590A (en) * 1954-09-13 1959-05-26 Gen Electric Electronic tube structure
US2933633A (en) * 1955-02-16 1960-04-19 Gen Electric Electric discharge device
US3041494A (en) * 1959-03-25 1962-06-26 Rca Corp High voltage rectifier tube
US3231778A (en) * 1963-06-20 1966-01-25 Sylvania Electric Prod Signal barrier

Also Published As

Publication number Publication date
GB1192970A (en) 1970-05-28
NL6711517A (de) 1968-02-28
DE1564506B1 (de) 1970-08-20
CH470751A (de) 1969-03-31

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