US2730643A - Electric discharge tube - Google Patents

Electric discharge tube Download PDF

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Publication number
US2730643A
US2730643A US298979A US29897952A US2730643A US 2730643 A US2730643 A US 2730643A US 298979 A US298979 A US 298979A US 29897952 A US29897952 A US 29897952A US 2730643 A US2730643 A US 2730643A
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United States
Prior art keywords
layer
electric discharge
discharge tube
metal layer
envelope
Prior art date
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Expired - Lifetime
Application number
US298979A
Inventor
Gier Johannes De
Peper Jan
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Hartford National Bank and Trust Co
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Hartford National Bank and Trust Co
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    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01J—ELECTRIC DISCHARGE TUBES OR DISCHARGE LAMPS
    • H01J61/00—Gas-discharge or vapour-discharge lamps
    • H01J61/02—Details
    • H01J61/30—Vessels; Containers
    • H01J61/35—Vessels; Containers provided with coatings on the walls thereof; Selection of materials for the coatings
    • C—CHEMISTRY; METALLURGY
    • C23—COATING METALLIC MATERIAL; COATING MATERIAL WITH METALLIC MATERIAL; CHEMICAL SURFACE TREATMENT; DIFFUSION TREATMENT OF METALLIC MATERIAL; COATING BY VACUUM EVAPORATION, BY SPUTTERING, BY ION IMPLANTATION OR BY CHEMICAL VAPOUR DEPOSITION, IN GENERAL; INHIBITING CORROSION OF METALLIC MATERIAL OR INCRUSTATION IN GENERAL
    • C23C—COATING METALLIC MATERIAL; COATING MATERIAL WITH METALLIC MATERIAL; SURFACE TREATMENT OF METALLIC MATERIAL BY DIFFUSION INTO THE SURFACE, BY CHEMICAL CONVERSION OR SUBSTITUTION; COATING BY VACUUM EVAPORATION, BY SPUTTERING, BY ION IMPLANTATION OR BY CHEMICAL VAPOUR DEPOSITION, IN GENERAL
    • C23C14/00—Coating by vacuum evaporation, by sputtering or by ion implantation of the coating forming material
    • C23C14/06—Coating by vacuum evaporation, by sputtering or by ion implantation of the coating forming material characterised by the coating material
    • C23C14/14—Metallic material, boron or silicon
    • C23C14/18—Metallic material, boron or silicon on other inorganic substrates
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01B—CABLES; CONDUCTORS; INSULATORS; SELECTION OF MATERIALS FOR THEIR CONDUCTIVE, INSULATING OR DIELECTRIC PROPERTIES
    • H01B1/00—Conductors or conductive bodies characterised by the conductive materials; Selection of materials as conductors
    • 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
    • H01J29/10—Screens on or from which an image or pattern is formed, picked up, converted or stored
    • H01J29/18—Luminescent screens
    • H01J29/28—Luminescent screens with protective, conductive or reflective layers
    • 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
    • H01J29/86—Vessels; Containers; Vacuum locks
    • H01J29/88—Vessels; Containers; Vacuum locks provided with coatings on the walls thereof; Selection of materials for the coatings
    • 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
    • Y10T428/24—Structurally defined web or sheet [e.g., overall dimension, etc.]
    • Y10T428/24479—Structurally defined web or sheet [e.g., overall dimension, etc.] including variation in thickness

Definitions

  • a conductive layer which may consist of very diiferent materials in accordance with its function, is provided on the inner side of the glass wall.
  • Carbon layers are extensively used, the starting material often being that commercially available as Aquadag.
  • a reflecting surface is particularly disadvantageous in cathoderay tubes comprising a luminescent screen, since the screen in use emits light in the direction of the cathode which is reflected by the reflecting metal layer on the wall and produces a general diffuse illumination detracting from the intensity contrast of the image.
  • a high gas pressure is troublesome during vaporisation, since it prohibits the use of shielding means, for example for leaving free the window through which the image is viewed. Consequently it is necessary either to vaporise the metal through a gaseous atmosphere or to provide a reflecting layer.
  • the present invention has for its object to provide an improved method of manufacturing and an improved electric discharge tube.
  • an electric discharge tube comprising an envelope atleast in part of glass and internally at least in part provided with a metal layer of low reflection produced by vaporisation, is characterized in that the layer consists of an alloy or a mixture of "nickel and chromium, use being preferably made of an alloy or a mixture containing 80% to 90% of nickel and 20% to 10% of chromium.
  • the chromium-nickel alloy or the chromium-nickel mixture used according to the invention may easily be ep r 'z dptor exampl from a filament by heatin the latter in a gaseous atmosphere at a pressure below 5010*? of mercury, the layer being such as to provide only little reflection.
  • a layer'40 A. to 100 A. thick has a resistance of only 10,000 to 1,000 ohms, measured between two copper strips 1 cm. long and spaced apart by a distance of 1 cm; Such a layer absorbs approximately 20% to 40% of the light.
  • This fact may be used to advantage when such a layer is used in a cathode ray tube; in such tubes it is frequently desirableto have a layer absorbing .of from 20% to 4.0% of the light between the luminous's'creen and its glass support, since. as is well known, such a light-absorbing layer increases the intensity contrast of an image produced on the screen.
  • Both layers can now be applied in one operation, an additional advantage being that the layer has a very uniform light absorption throughout the visible part of the spectrum.
  • the low resistance of a wall layer absorbing of from 20% to 40% of the light is furthermore advantageous, since the screen will then not become charged.
  • the electrical conductivity of the layer on that part of a cathode-ray tube, not acting as a window, is deemed too low or if the layer is provided in a tube without a luminescent screen, more metal may be applied by vaporisation.
  • the window is to be covered with a layer having an absorption of from 20% to 40% and the remainder of the wall with a thicker layer (consequently having a greater absorption), shielding means may be provided after the first phase of vaporisation to prevent more metal depositing on the window portion. Since vaporisation may take place at very low gas pressures it is possible to obtain a sharply defined demarcation between two parts of the layer.
  • chromium-nickel alloy or chromiumnickel mixture has the additional advantage that the layer adheres tenaciously to the glass wall, an advantage further promoted by the low gas pressure during vaporisation. Furthermore, the alloy or mixture absorbs and adsorbs only small quantities of gas.
  • the invention is illustrated in the accompanying drawing in which a cathode-ray tube is represented schematically.
  • the tube is indicated herein by l, the electrode system by 2, the image window by 3 and the luminescent layer thereon by 4, with 5 is denominated the chromiumnickel wall layer.
  • An electric discharge tube comprising an envelope having a glass portion, and a low-reflecting metal layer deposited on the inner surface of said glass portion, said metal layer consisting of a mixture of nickel and chr0- mium and being produced by vaporization.
  • An electric discharge tube comprising an envelope having a glass portion, and a low-reflecting metal layer deposited on the inner surface of said glass portion, said metal layer consisting of a mixture of 30 to of nickel and 20 to 10% of chromium and being produced by vaporization.
  • a method of making an electric discharge tube having an envelope constituted partially of glass and a lowreflecting metal layer thereon which comprises the steps of exhausting the envelope to a pressure below 50 10 mms. of mercury, and vaporizing chromium and nickel from a heated filament onto the glass portion of the envelope to form the metal layer.
  • a method of making a cathode-ray tube having a glass envelope including a window and a low-reflecting metal layer thereon which comprises the steps of exhausting the envelope to a pressure below SOXIO- mms. of mercury, vaporizing chromium and nickel from a References Cited in the file of this patent UNITED STATES PATENTS 2,183,302 Brauer Dec. 12, 1939 2,207,656 Cartwright July 9, 1940 2,266,595 Fraenckel Dec. 16, 1941 2,271,239 Vokes Jan. 27, 1942 2,280,135 Ward Apr. 21, 1942 2,366,516 Geffcken u Jan. 2, 1945 2,409,514 Pratt Oct. 15, 1946

Description

Jan. 10,1956
J. DE GIER ET AL 2,730,643
ELECTRIC DISCHARGE TUBE Filed July 15, 1952 l/v VENTORS JAN PEPE/a JOHA/VNEJ DE G/E/a I discharge tubes.
United States Patent C 2. 739??? 7 ELECTRIC DISCHARGE TUBE a s ti Gi r a d an .Peper, li us b yeu, Nethe assignors to ICIQIHQEQ National Bani Trust Company, Hartford,- (161111., as -triistee L n ration July 15, 1952, Qerjal p10,. 298,919
august careut-t i envelope, a conductive layer, which may consist of very diiferent materials in accordance with its function, is provided on the inner side of the glass wall. Carbon layers are extensively used, the starting material often being that commercially available as Aquadag.
However, the use of a, carbon layer suffers from many disadvantages, the most serious of them being that the layer must be fired for a considerable time in order to free it from absorbed and adsorbed gases and from the binding material used. Therefore, carbon has, for example, been replaced by oxides of chromium or nickel which occlude smaller quantities of gas. These oxides, however, still require the use of a binder. Moreover,
' they suffer from the disadvantage of being comparatively poor conductors of electricity.
' Furthermore, it has been proposed to employ metals, for example aluminium, which is easy to apply by vaporisation. Vaporisation of metal requires a comparatively high gas pressure in the discharge tube to obtain a nonreflecting surface as is-very desirable in many types of This high pressure has a limitation, however, in that the metal cannot be vaporized after the tube has been completely finished, since the gas pressure in a finished tube must be very low. Moreover, a high gas pressure has the drawback that the vaporising metal is scattered and therefore no shielding means can be provided with a view to leaving free given parts of the wall of the tube or of the electrode system.
A reflecting surface is particularly disadvantageous in cathoderay tubes comprising a luminescent screen, since the screen in use emits light in the direction of the cathode which is reflected by the reflecting metal layer on the wall and produces a general diffuse illumination detracting from the intensity contrast of the image. However, a high gas pressure is troublesome during vaporisation, since it prohibits the use of shielding means, for example for leaving free the window through which the image is viewed. Consequently it is necessary either to vaporise the metal through a gaseous atmosphere or to provide a reflecting layer.
The present invention has for its object to provide an improved method of manufacturing and an improved electric discharge tube.
According to the invention, an electric discharge tube comprising an envelope atleast in part of glass and internally at least in part provided with a metal layer of low reflection produced by vaporisation, is characterized in that the layer consists of an alloy or a mixture of "nickel and chromium, use being preferably made of an alloy or a mixture containing 80% to 90% of nickel and 20% to 10% of chromium.
The chromium-nickel alloy or the chromium-nickel mixture used according to the invention may easily be ep r 'z dptor exampl from a filament by heatin the latter in a gaseous atmosphere at a pressure below 5010*? of mercury, the layer being such as to provide only little reflection.
heelect-riiralconductivity of an alloy or mixture layer even if'thin, is considerable. Thus, a layer'40 A. to 100 A. thick has a resistance of only 10,000 to 1,000 ohms, measured between two copper strips 1 cm. long and spaced apart by a distance of 1 cm; Such a layer absorbs approximately 20% to 40% of the light. This fact may be used to advantage when such a layer is used in a cathode ray tube; in such tubes it is frequently desirableto have a layer absorbing .of from 20% to 4.0% of the light between the luminous's'creen and its glass support, since. as is well known, such a light-absorbing layer increases the intensity contrast of an image produced on the screen. Both layers can now be applied in one operation, an additional advantage being that the layer has a very uniform light absorption throughout the visible part of the spectrum.
The low resistance of a wall layer absorbing of from 20% to 40% of the light is furthermore advantageous, since the screen will then not become charged.
If the electrical conductivity of the layer on that part of a cathode-ray tube, not acting as a window, is deemed too low or if the layer is provided in a tube without a luminescent screen, more metal may be applied by vaporisation. If the window is to be covered with a layer having an absorption of from 20% to 40% and the remainder of the wall with a thicker layer (consequently having a greater absorption), shielding means may be provided after the first phase of vaporisation to prevent more metal depositing on the window portion. Since vaporisation may take place at very low gas pressures it is possible to obtain a sharply defined demarcation between two parts of the layer.
Naturally, it is also possible to leave the window portion entirely free from a layer.
The use of a chromium-nickel alloy or chromiumnickel mixture has the additional advantage that the layer adheres tenaciously to the glass wall, an advantage further promoted by the low gas pressure during vaporisation. Furthermore, the alloy or mixture absorbs and adsorbs only small quantities of gas.
The invention is illustrated in the accompanying drawing in which a cathode-ray tube is represented schematically. The tube is indicated herein by l, the electrode system by 2, the image window by 3 and the luminescent layer thereon by 4, with 5 is denominated the chromiumnickel wall layer.
What we claim is:
1. An electric discharge tube comprising an envelope having a glass portion, and a low-reflecting metal layer deposited on the inner surface of said glass portion, said metal layer consisting of a mixture of nickel and chr0- mium and being produced by vaporization.
2. An electric discharge tube comprising an envelope having a glass portion, and a low-reflecting metal layer deposited on the inner surface of said glass portion, said metal layer consisting of a mixture of 30 to of nickel and 20 to 10% of chromium and being produced by vaporization.
3 porization, and a luminescent screen deposited on the portion of the metal layer covering the window.
5. A cathodeqay tube as claimed in claim 4 in which the metal layer covering the window has a thickness between about 40 and 100 A., and the remainder of the metal layer has a greater thickness.
6. A method of making an electric discharge tube having an envelope constituted partially of glass and a lowreflecting metal layer thereon, which comprises the steps of exhausting the envelope to a pressure below 50 10 mms. of mercury, and vaporizing chromium and nickel from a heated filament onto the glass portion of the envelope to form the metal layer.
7. A method of making a cathode-ray tube having a glass envelope including a window and a low-reflecting metal layer thereon, which comprises the steps of exhausting the envelope to a pressure below SOXIO- mms. of mercury, vaporizing chromium and nickel from a References Cited in the file of this patent UNITED STATES PATENTS 2,183,302 Brauer Dec. 12, 1939 2,207,656 Cartwright July 9, 1940 2,266,595 Fraenckel Dec. 16, 1941 2,271,239 Vokes Jan. 27, 1942 2,280,135 Ward Apr. 21, 1942 2,366,516 Geffcken u Jan. 2, 1945 2,409,514 Pratt Oct. 15, 1946

Claims (1)

1. AN ELECTRIC DISCHARGE TUBE COMPRISING AN ENVELOPE HAVING A GLASS PORTION, AND A LOW REFLECTING METAL LAYER DEPOSITED ON THE INNER SURFACE OF SAID GLASS PORTION, SAID METAL LAYER CONSISTING OF A MIXTURE OF NICKLE AND CHROMIUM AND BEING PRODUCED BY VAPORIZATION.
US298979A 1951-08-25 1952-07-15 Electric discharge tube Expired - Lifetime US2730643A (en)

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
NL304168X 1951-08-25

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US2730643A true US2730643A (en) 1956-01-10

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US (1) US2730643A (en)
BE (1) BE513715A (en)
CH (1) CH304168A (en)
DE (1) DE917680C (en)
FR (1) FR1071710A (en)
GB (1) GB723384A (en)
NL (1) NL92230C (en)

Cited By (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3027218A (en) * 1958-02-21 1962-03-27 Philips Corp Manufacture of electron discharge tubes having a photo-conductive target
US3138734A (en) * 1960-07-01 1964-06-23 Corning Glass Works Prevention of cathode poisoning in an electron tube

Families Citing this family (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
DE1054594B (en) * 1956-09-04 1959-04-09 Gen Electric Metal-ceramic tubes and method for applying a resistance layer to the inner surface of a ceramic ring for such a tube
US3350594A (en) * 1963-08-02 1967-10-31 Emi Ltd Image intensifier having continuous conducting layer between porous metallic coating and luminescent layer
DE3629996A1 (en) * 1986-09-03 1988-03-17 Flachglas Ag ATTACHMENT UNIT FOR THE CATHODE RAY TUBES OF MONITORS, TELEVISION DEVICES AND THE LIKE

Citations (7)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US2183302A (en) * 1936-01-22 1939-12-12 Fernseh Ag Method for producing coatings of high ohmic resistance in the interior of vacuum tubes
US2207656A (en) * 1938-12-27 1940-07-09 Research Corp Process of decreasing reflection of light from surfaces, and articles so produced
US2266595A (en) * 1937-07-14 1941-12-16 Gen Electric Electric discharge device
US2271239A (en) * 1940-09-28 1942-01-27 Eastman Kodak Co Nonreflecting coating for galss
US2280135A (en) * 1940-02-21 1942-04-21 Theodore W H Ward Conductive coating for glass and method of application
US2366516A (en) * 1939-05-27 1945-01-02 Geffcken Walter Method for producing layers on solid objects
US2409514A (en) * 1945-01-30 1946-10-15 Rca Corp Cathode-ray tube

Patent Citations (7)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US2183302A (en) * 1936-01-22 1939-12-12 Fernseh Ag Method for producing coatings of high ohmic resistance in the interior of vacuum tubes
US2266595A (en) * 1937-07-14 1941-12-16 Gen Electric Electric discharge device
US2207656A (en) * 1938-12-27 1940-07-09 Research Corp Process of decreasing reflection of light from surfaces, and articles so produced
US2366516A (en) * 1939-05-27 1945-01-02 Geffcken Walter Method for producing layers on solid objects
US2280135A (en) * 1940-02-21 1942-04-21 Theodore W H Ward Conductive coating for glass and method of application
US2271239A (en) * 1940-09-28 1942-01-27 Eastman Kodak Co Nonreflecting coating for galss
US2409514A (en) * 1945-01-30 1946-10-15 Rca Corp Cathode-ray tube

Cited By (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3027218A (en) * 1958-02-21 1962-03-27 Philips Corp Manufacture of electron discharge tubes having a photo-conductive target
US3138734A (en) * 1960-07-01 1964-06-23 Corning Glass Works Prevention of cathode poisoning in an electron tube

Also Published As

Publication number Publication date
NL92230C (en)
FR1071710A (en) 1954-09-03
BE513715A (en)
DE917680C (en) 1954-09-09
CH304168A (en) 1954-12-31
GB723384A (en) 1955-02-09

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