US2908838A - Aperture mask treatment to prevent cathode poisoning - Google Patents

Aperture mask treatment to prevent cathode poisoning Download PDF

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Publication number
US2908838A
US2908838A US642073A US64207357A US2908838A US 2908838 A US2908838 A US 2908838A US 642073 A US642073 A US 642073A US 64207357 A US64207357 A US 64207357A US 2908838 A US2908838 A US 2908838A
Authority
US
United States
Prior art keywords
mask
glass
hydrogen
electron
cathode
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
US642073A
Other languages
English (en)
Inventor
Martin E Nordberg
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.)
Corning Glass Works
Original Assignee
Corning Glass Works
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 BE565080D priority Critical patent/BE565080A/xx
Priority to NL225220D priority patent/NL225220A/xx
Application filed by Corning Glass Works filed Critical Corning Glass Works
Priority to US642073A priority patent/US2908838A/en
Priority to GB5567/58A priority patent/GB841405A/en
Priority to FR1200214D priority patent/FR1200214A/fr
Priority to DEC16351A priority patent/DE1091674B/de
Priority to CH347225D priority patent/CH347225A/fr
Application granted granted Critical
Publication of US2908838A publication Critical patent/US2908838A/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
    • H01J29/02—Electrodes; Screens; Mounting, supporting, spacing or insulating thereof
    • H01J29/06—Screens for shielding; Masks interposed in the electron stream
    • H01J29/07—Shadow masks for colour television tubes

Definitions

  • This invention relates to an improved perforate mask for assembly in a cathode ray tube of the type used in multicolor television receivers and to a cathode ray tube embodying such mask.
  • Multicolor television systems operate on the general principle of emitting a stream of electrons from one or more electron guns mounted in the neck of a cathode ray tube and directing such stream United States Patent a plurality of electron beams passing through the apertures or perforations in the mask to the patternof phosphors on the face. of the tube.
  • Multicolor television systems of this sort are described in detail in the patent litice being used in cathode ray tubes for absorption of electrons.
  • Fig. l is a schematic representation, largely in section, of a cathode ray tube and,
  • Fig. 2 is an enlarged fragmentary view in section of a perforate mask in accordance with the invention.
  • the cathode ray tube schematically represented in Fig. 1 and designated by the numeral 10, has an electron gun 12 mounted in the tube neck 14 and a viewing screen '16 composed of a phosphor coating 18, of suitable composition and pattern formulticolor televisingjapplied to the inside surface of transparent face plate or panel 20 which forms the opposite, enlarged end of the tube.
  • the phosphor coating is applied in any known manner in a dot, stripe or other type. of pattern suitable for the purpose.
  • Perforate glass mask 2 2 is mounted intermediate electron gun 12 and screen v16, by any suitable conventional means, not specifically shown.
  • Fig. 2 a fragment of mask 22 is shown greatly exaggerated to better illustrate chemically perforated apertures 26 which are too small and too numerous to be satisfactorily shown in a full viewsuch as Fig. 1..
  • the diameter of apertures 26 is 10 mils and they are spaced 28 mils apart center to center.
  • mask 22 is shown fiat, and apertures 26, as shown, are formed normal to the electron intercepting surface.
  • apertures 26 may be formed at angles up to 25 or so from normal depending on the location and geometry of the tube components. The angle of each aperture will be such as to provide alignment of electron gun, apertures and screen elements for proper screen scanning.
  • an electron absorbing, perforate mask, for assembly and use in a cathode ray tube is produced by firing a chemically perforated glass mask in areducingatmosphere containing free hydrogen.
  • the efiectiveness of this treatment indicates that the poisoning agent released during electron bombardment of an untreated glass mask is oxygen, and that preliminary firing ofthe glass in the presence of hydrogen, that is in accordance with the present invention, causes such oxygen to combine with the hydrogen or to otherwise be rendered unavailable for subsequent release.
  • This theory is supported by tests in which gases evolved from various glasses under electron bombardment have been collected and analyzed, such test glasses including both hydrogen-fired and untreated glass capable of being chemically perforated.
  • the atmosphere in which the glass is fired prefe rably contains at least 25% hydrogen. While smaller amounts may be effective the amount of time required is usually too long for practical purposes.
  • Theelfectiveness of the hydrogen firing increases with temperature and it is therefore desirable to employ the maximum firing temperature' possible without distortion of the glass. This maximum temperature will depend in large measure on the viscosity characteristics of the glass and will generally be on the order of C. below the glass softening point.
  • a mask adapted to absorb electrons in a cathode ray tube and having a plurality of perforations extending therethrough which transmit electrons to form a corresponding plurality of electron beams, said mask consisting of a thin'sheet of perforated glass having a surface incapable of evolving cathode poisoning gas upon being subjected to electron bombardment.
  • a perforated glass mask having a surface incapable of evolving cathode gas upon being subjected to electron bombardment.
  • a method of treating a perforate glass mask for incorporation into a cathode ray tube which includes firing such mask in a reducing atmosphere composed in part at least of hydrogen and forming a surface on said glass which is capable of absorbing electrons without appreciable evolution of cathode poisoning gas.
  • the method which comprises treating the mask in a hydrogen-containing atmosphere at an elevated temperature and forming thereon a surface capable of absorbing electrons without appreciable evolution of cathode poisoning gas.

Landscapes

  • Electrodes For Cathode-Ray Tubes (AREA)
  • Manufacture Of Electron Tubes, Discharge Lamp Vessels, Lead-In Wires, And The Like (AREA)
  • Surface Treatment Of Glass (AREA)
US642073A 1957-02-25 1957-02-25 Aperture mask treatment to prevent cathode poisoning Expired - Lifetime US2908838A (en)

Priority Applications (7)

Application Number Priority Date Filing Date Title
BE565080D BE565080A (en, 2012) 1957-02-25
NL225220D NL225220A (en, 2012) 1957-02-25
US642073A US2908838A (en) 1957-02-25 1957-02-25 Aperture mask treatment to prevent cathode poisoning
GB5567/58A GB841405A (en) 1957-02-25 1958-02-20 Aperture mask treatment to prevent cathode poisoning
FR1200214D FR1200214A (fr) 1957-02-25 1958-02-21 Traitement de masque perforé pour éviter l'empoisonnement de la cathode
DEC16351A DE1091674B (de) 1957-02-25 1958-02-22 Verfahren zur Ausheizung einer aus Glas bestehenden Lochmaske fuer Kathodenstrahlroehren
CH347225D CH347225A (fr) 1957-02-25 1958-02-24 Procédé de traitement d'un masque perforé de tube à rayons cathodiques, permettant d'éviter l'empoisonnement de la cathode

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
US642073A US2908838A (en) 1957-02-25 1957-02-25 Aperture mask treatment to prevent cathode poisoning

Publications (1)

Publication Number Publication Date
US2908838A true US2908838A (en) 1959-10-13

Family

ID=24575074

Family Applications (1)

Application Number Title Priority Date Filing Date
US642073A Expired - Lifetime US2908838A (en) 1957-02-25 1957-02-25 Aperture mask treatment to prevent cathode poisoning

Country Status (7)

Country Link
US (1) US2908838A (en, 2012)
BE (1) BE565080A (en, 2012)
CH (1) CH347225A (en, 2012)
DE (1) DE1091674B (en, 2012)
FR (1) FR1200214A (en, 2012)
GB (1) GB841405A (en, 2012)
NL (1) NL225220A (en, 2012)

Cited By (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3760214A (en) * 1971-12-30 1973-09-18 Hitachi Ltd Shadow masks for use in colour picture tubes
US4621214A (en) * 1984-04-19 1986-11-04 Rca Corporation Color selection means having a charged insulator portion for a cathode-ray tube
US4622084A (en) * 1985-01-29 1986-11-11 Chang Kern K N Method of sealing a mount in a cathode-ray tube

Citations (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US2279168A (en) * 1940-02-29 1942-04-07 Westinghouse Electric & Mfg Co Process for kovar-glass seals
US2347982A (en) * 1941-12-31 1944-05-02 Gen Electric Electron lens
US2392099A (en) * 1943-07-29 1946-01-01 Bell Telephone Labor Inc Manufacture of glass sealed contact units
US2777084A (en) * 1952-04-12 1957-01-08 Gen Electric Plastic electrode structure for electron tubes
US2805360A (en) * 1954-10-08 1957-09-03 Gen Dynamics Corp Image storage apparatus

Patent Citations (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US2279168A (en) * 1940-02-29 1942-04-07 Westinghouse Electric & Mfg Co Process for kovar-glass seals
US2347982A (en) * 1941-12-31 1944-05-02 Gen Electric Electron lens
US2392099A (en) * 1943-07-29 1946-01-01 Bell Telephone Labor Inc Manufacture of glass sealed contact units
US2777084A (en) * 1952-04-12 1957-01-08 Gen Electric Plastic electrode structure for electron tubes
US2805360A (en) * 1954-10-08 1957-09-03 Gen Dynamics Corp Image storage apparatus

Cited By (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3760214A (en) * 1971-12-30 1973-09-18 Hitachi Ltd Shadow masks for use in colour picture tubes
US4621214A (en) * 1984-04-19 1986-11-04 Rca Corporation Color selection means having a charged insulator portion for a cathode-ray tube
US4622084A (en) * 1985-01-29 1986-11-11 Chang Kern K N Method of sealing a mount in a cathode-ray tube

Also Published As

Publication number Publication date
DE1091674B (de) 1960-10-27
BE565080A (en, 2012)
CH347225A (fr) 1960-06-30
NL225220A (en, 2012)
FR1200214A (fr) 1959-12-18
GB841405A (en) 1960-07-13

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