US2372455A - Cathode-ray tube - Google Patents

Cathode-ray tube Download PDF

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Publication number
US2372455A
US2372455A US489367A US48936743A US2372455A US 2372455 A US2372455 A US 2372455A US 489367 A US489367 A US 489367A US 48936743 A US48936743 A US 48936743A US 2372455 A US2372455 A US 2372455A
Authority
US
United States
Prior art keywords
cathode
ray tube
tube
electron
electrons
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
US489367A
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English (en)
Inventor
Andrew F Stanier
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.)
Allen B du Mont Laboratories Inc
Original Assignee
Allen B du Mont Laboratories Inc
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
Priority to BE462893D priority Critical patent/BE462893A/xx
Application filed by Allen B du Mont Laboratories Inc filed Critical Allen B du Mont Laboratories Inc
Priority to US489367A priority patent/US2372455A/en
Priority to GB7993/44A priority patent/GB585685A/en
Application granted granted Critical
Publication of US2372455A publication Critical patent/US2372455A/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
    • H01J29/00—Details of cathode-ray tubes or of electron-beam tubes of the types covered by group H01J31/00
    • H01J29/46—Arrangements of electrodes and associated parts for generating or controlling the ray or beam, e.g. electron-optical arrangement
    • H01J29/48—Electron guns
    • H01J29/485—Construction of the gun or of parts thereof

Definitions

  • This invention relates to electronic tubes such as audions or cathode-ray tubes, for example, although it is not restricted to such vacuum tubes.
  • the invention relates more particularly to the cathodes of these tubes.
  • cathodes for electronic tubes have been made of metal or compositions which will,
  • a vacuum tube such as is used for producing a cathode-ray beam is shown somewhat diagrammatically for illustrative purposes.
  • Fig. 1 is a side view of a cathode-ray tube; and Fig. 2 is a side view of the cathode of this tube on an enlarged scale.
  • reference characterl indicates the evacuated tube that is provided with a heater 2, cathode 3, control grid 4, first anode 5, second anode 8, and pairs 1 and 8 of deflection plates for the cathode-ray beam. .7
  • the face of the cathode 8 is coated with material III that has the characteristic of emitting a very large number 01' electrons when heated.
  • the gist of this invention is to prevent this emissive material ill from becoming contaminated with impurities-that would decrease the emis- 35 a substantially pure carbon sivity. It has been found that the metals or materials which have been used heretofore for making cathodes contain enough impurities, even when refined by the best known methods, to contaminate the layer of emissive material sufflciently'to reduce the emissivity very greatly.
  • the electron-emissive material H such as oxides of metals or oxides of cadmium, barium and caesium, for example, mentioned above, can be applied as indicated in Fig.
  • the purified carbon or graphite used in making the cathode 3 will withstand sufiicient heat to heat the coating ID to the desired temperature for emitting electrons at the desired rate, and no noticeable contamination of this material Ill occurs during the normal life of the tube I.
  • a cathode for a cathoderay tube consist- I ing or a substantially pure carbon support having a depression therein and emissive material locat-- ed in said depression.
  • a cathode-ray tube electrode constructed of tupport having a surface depression therein in which cathode-emissive material which has a high coemcient of electron 4 emissivity is located.

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  • Solid Thermionic Cathode (AREA)
US489367A 1943-06-02 1943-06-02 Cathode-ray tube Expired - Lifetime US2372455A (en)

Priority Applications (3)

Application Number Priority Date Filing Date Title
BE462893D BE462893A (is") 1943-06-02
US489367A US2372455A (en) 1943-06-02 1943-06-02 Cathode-ray tube
GB7993/44A GB585685A (en) 1943-06-02 1944-04-28 Improvements in and relating to indirectly heated cathodes for electron discharge devices

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
US489367A US2372455A (en) 1943-06-02 1943-06-02 Cathode-ray tube

Publications (1)

Publication Number Publication Date
US2372455A true US2372455A (en) 1945-03-27

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ID=23943565

Family Applications (1)

Application Number Title Priority Date Filing Date
US489367A Expired - Lifetime US2372455A (en) 1943-06-02 1943-06-02 Cathode-ray tube

Country Status (3)

Country Link
US (1) US2372455A (is")
BE (1) BE462893A (is")
GB (1) GB585685A (is")

Cited By (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US2727177A (en) * 1952-02-11 1955-12-13 Westinghouse Electric Corp Electrostatic lens system

Cited By (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US2727177A (en) * 1952-02-11 1955-12-13 Westinghouse Electric Corp Electrostatic lens system

Also Published As

Publication number Publication date
BE462893A (is")
GB585685A (en) 1947-02-19

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