US3422220A - Color television display tube with ferromagnetic screening member - Google Patents

Color television display tube with ferromagnetic screening member Download PDF

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Publication number
US3422220A
US3422220A US549036A US3422220DA US3422220A US 3422220 A US3422220 A US 3422220A US 549036 A US549036 A US 549036A US 3422220D A US3422220D A US 3422220DA US 3422220 A US3422220 A US 3422220A
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United States
Prior art keywords
window
cone
tube
juncture
color television
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
US549036A
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English (en)
Inventor
Robert Richard Bathelt
Constantius Johannes Wal Panis
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Philips North America LLC
US Philips Corp
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US Philips Corp
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Filing date
Publication date
Application filed by US Philips Corp filed Critical US Philips Corp
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Publication of US3422220A publication Critical patent/US3422220A/en
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    • 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
    • H01J29/867—Means associated with the outside of the vessel for shielding, e.g. magnetic shields
    • 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
    • H01J29/87—Arrangements for preventing or limiting effects of implosion of vessels or containers

Definitions

  • the invention relates to a color television display tube provided with a ferromagnetic screening hood which covers the major part of the cone. Moreover, the cone and the window are provided with ground edges, which are connected with each other by means of a readily melting kind of glass (glaze), while the side face of the window is provided with smoothly ground glass reference lugs.
  • the invention relates to such a display tube in which the screening hood serves, in addition, to prevent implosion.
  • annular band is placed around the outer side of the window and the space between this band and the glass filled with a suitable material. Although the annular band does not exert a pressure on the bulb of the tube, cracks in the glass are prevented from continuing beneath the band, so that implosion is avoided.
  • annular band is broad or narrow or whether the sealing edges of the cone and the window are covered or are not covered by the filling material.
  • the width of the annular band is usually chosen in accordance with the desired place of said fastening members.
  • edges of the cone and the window to be connected with each other are, however, not sealed, but they are interconnected by means of a glaze, since the phosphor screen and the color selection electrodes would otherwise become too hot and oxidation and deformation might occur.
  • the side face of the upright edge of'the cup-shaped window is provided with glass reference lugs, which are ground smooth until they have the correct height. These lugs serve for fixing the window accurately in a given position during the manufacture of the phosphor screen.
  • annular band for a monochrome display tube having a width such that it covers the junction must therefore not be applied to a color television display tube without taking further steps to avoid those difficulties.
  • a broad annular band is, however, highly desirable for a color display tube, since such a display tube is comparatively heavy due to the provision of the color selection elec- 3,422,220 Patented Jan. 14, 1969 trodes, which are usually fastened to a rigid metal frame.
  • a suitable embodiment of such a display tube is obtained, in accordance with the invention, by buildin up the ferromagnetic screening hood from two inter-engaging, annular portions.
  • One portion surrounding the Window holds the members for fastening the tube in the cabinet, the width of that portion being such that it extends beyond the juncture between the cone and the window.
  • the space between this annular portion and the side face of the window is filled round about at least partly with a suitable hardenable filling material, so that this annular portion operates as an anti-implosion band.
  • steps are taken for keeping the juncture between the cone and the window and the ground faces of the reference lugs clear of adhesive contact with said filling material.
  • the reference lugs are preferably covered with adhesive tape, while the seam between the window and the cone may also be covered with adhesive tape. It is furthermore possible to apply a liquid layer, for example oil, to said faces, or a suitable paint.
  • the space between the :annular portion adjacent the display face and the bulb is preferably filled up to about 5 mms. from the juncture, since this requires a smaller quantity of filling material, while the juncture need not be covered with adhesive tape.
  • the two portions of the screening hood prefferably be electrically insulated from each other, since the portion surrounding the cone is connected with the conducting layer applied to the cone, which layer, in turn, is in contact with the chassis.
  • the chassis is, in general, connected with one terminal of an electrical power supply, so that it may be at a potential with respect to ground.
  • the embodiment according to the invention provides a suitable combination of an antiimplosion ring band and the magnetic screening hood.
  • the space between the cone and the associated portion of the screening hood also may be filled with a filling material, this is of no practical use.
  • This portion of the screening hood can best be caused to bear on the cone wall by means of ridges or spacers.
  • FIG. 1 is a partial sectional view
  • FIG. 2 is a side elevation of a color television display tube according to the invention.
  • a color television tube includes a glass window and a glass cone 2, the edges 4 and 5 of which are joined by a glaze 3, after these edges 4 and 5 have been ground flat.
  • sharp side edges are formed, which may be readily damaged and may exhibit hairline cracks.
  • a metal frame 6 is arranged inside the bulb on which a color selection electrode 7, e.g., a shadow mask, is secured.
  • a phosphor screen 8 consisting of a great number of dots or phosphors luminescing in the colors red, green and blue is applied to the inner side of the display surface of window 1.
  • Window 1 and cone 2 are surrounded by a ferromagnetic screening hood consisting of an annular portion 9, which surrounds the display area, and an annular portion 10, which partly surrounds the cone and extends up to a few centimeters from the foremost deflection coil.
  • Portion 10 is joined to portion 9 by a ring 11, for example of a synthetic resin, having an H-shaped cross section, but is "ice insulated electrically from the latter portion.
  • Portion 10 is furthermore connected electrically by means of one or more contact springs 12 to the conducting layer 13 on the cone and bears on the cone by means of depressed portions 16.
  • On the side face of window 1 eight ground glass reference lugs 17 are provided.
  • Annular portion 9 extends beyond juncture 3 and is provided with welded ears 14, which serve for fastening the display tube in a cabinet. Bars 14 are located in a plane which passes approximately through the center of gravity of the tube, so that no bending forces are exerted on the annular portion 9.
  • the space between portion 9 and the side face of the window 1 is filled partly round about with a suitable hardenable material, preferably a synthetic resin or a mixture of substances. If desired, graphite or a metal powder may be added to the filling material, so that it is slightly conductive and the portion 9 is connected through a high-value resistance to the coating 13, so that electrostatic charges are conducted away from this portion.
  • the reference lugs 17 were previously covered with a strip of adhesive tape or a layer of a suitable paint 18, to keep the ground surfaces clear of filling material 15.
  • a strip of adhesive tape or a layer of a suitable paint 18 to keep the ground surfaces clear of filling material 15.
  • the portion 10 of the screen is connected to the source of electric power an insulating path of at least 4 mms. across the surface of the insulating ring 11 between the portions 9 and 10 must be left.
  • portion 9 can still operate as an anti-implosion band.
  • the rim of portion 9 may be left clear of the filling material and is suffi-ciently rigid to support the tube by means of the ears 14 in a cabinet, since the center of gravity of the tube is located in or near the plane of the ears 14.
  • the juncture like the reference lugs, may be covered with adhesive tape or a suitable layer of paint or the like, while the filling material may extend in this case across the seam. The quantity of filling material is then considerably greater, while covering of the juncture is an elaborate process.
  • the window of the tube may be arranged so as to project from the cabinet at the front, which may be advantageous in some cases.
  • Bars 14, for example, may be connected to the portion 9 in the re verse sense or they may be integral therewith.
  • the space around the seam of the window and the cone may be filled with a soft, elastic coating substance in order to prevent penetration of moisture, if a hard filling material which adheres poorly to glass is employed.
  • a cathode-ray tube for color television display comprising an envelope having adjoining cone and window portions having smoothly ground edges joined by a glazelike material, said window portion having a side face provided with reference extensions, a ferromagnetic screening hood surrounding said side face of the window and a major portion of the cone, said hood further comprising two joined annular portions, one of which surrounds and is spaced from the side-face of the window and supports members for positioning the tube in a housing, said portion having a width such that said portion extends beyond the juncture between the cone and the window, and a filler material filling the space between said portion and the side-face of the window whereby said portion serves an anti-implosion member, said juncture between the cone and the window and the surfaces of said reference extensions being free of an adhesive contact with said filler material.
  • a color television display tube as claimed in claim 1 in which the juncture between the window and the cone is coated with a layer of a substance which prevents adhesion of the filling material at the juncture.
  • a color television display tube as claimed in claim 1 in which the ground surfaces of the reference extensions and the juncture between the window and the cone are covered with an intermediate layer of a liquid which prevents adhesion of the filling material thereto.

Landscapes

  • Vessels, Lead-In Wires, Accessory Apparatuses For Cathode-Ray Tubes (AREA)
  • Image-Pickup Tubes, Image-Amplification Tubes, And Storage Tubes (AREA)
  • Hydrogenated Pyridines (AREA)
US549036A 1965-06-09 1966-05-10 Color television display tube with ferromagnetic screening member Expired - Lifetime US3422220A (en)

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
NL6507304A NL6507304A (en:Method) 1965-06-09 1965-06-09

Publications (1)

Publication Number Publication Date
US3422220A true US3422220A (en) 1969-01-14

Family

ID=19793333

Family Applications (1)

Application Number Title Priority Date Filing Date
US549036A Expired - Lifetime US3422220A (en) 1965-06-09 1966-05-10 Color television display tube with ferromagnetic screening member

Country Status (10)

Country Link
US (1) US3422220A (en:Method)
AT (1) AT259643B (en:Method)
BE (1) BE682209A (en:Method)
CH (1) CH446433A (en:Method)
DE (1) DE1462832A1 (en:Method)
DK (1) DK117724B (en:Method)
ES (1) ES327638A1 (en:Method)
GB (1) GB1146078A (en:Method)
NL (1) NL6507304A (en:Method)
NO (1) NO117866B (en:Method)

Cited By (10)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3541251A (en) * 1967-09-19 1970-11-17 Standard Elektrik Lorenz Ag Implosion-protecting frame for television picture tubes and process for its installation
US3569990A (en) * 1967-03-03 1971-03-09 Thorn Radio Valves And Tubes L Implosion protection apparatus for cathode ray tubes
US3614519A (en) * 1967-12-18 1971-10-19 Zenith Radio Corp Cathode-ray tube magnetic shield
JPS5743347A (en) * 1980-08-26 1982-03-11 Mitsubishi Electric Corp Cathode ray tube
JPS5851683A (ja) * 1981-09-22 1983-03-26 Mitsubishi Electric Corp 陰極線管装置の製造方法
US4551765A (en) * 1981-10-26 1985-11-05 Allied Corporation Cathode ray tube vibration isolator
US4556821A (en) * 1984-03-15 1985-12-03 Rca Corporation Color image display system having an improved external magnetic shield
US4560900A (en) * 1981-08-04 1985-12-24 Tokyo Shibaura Denki Kabushiki Kaisha Cathode ray tube device with electromagnetic shield casing
DE3608646A1 (de) * 1985-03-20 1986-09-25 Mitsubishi Denki K.K., Tokio/Tokyo Farbbildschirmroehre
DE3616906A1 (de) * 1985-05-20 1986-11-20 Mitsubishi Electric Corp Magnetisches abschirmsystem in einem farbfernsehempfaenger

Families Citing this family (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPS597731Y2 (ja) * 1979-06-07 1984-03-09 ソニー株式会社 陰極線管装置
IT1243083B (it) * 1990-09-28 1994-05-23 Videocolor Spa Tubo a raggi catodici dotato di una fascia anti-implosione

Citations (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3278682A (en) * 1963-04-03 1966-10-11 Philips Corp Implosion-resistant cathode-ray tube with mounting brackets
US3340358A (en) * 1962-01-29 1967-09-05 Philips Corp Cathode-ray tube
US3369074A (en) * 1965-04-02 1968-02-13 Warwick Electronics Inc Television tube shield and mounting structure

Patent Citations (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3340358A (en) * 1962-01-29 1967-09-05 Philips Corp Cathode-ray tube
US3278682A (en) * 1963-04-03 1966-10-11 Philips Corp Implosion-resistant cathode-ray tube with mounting brackets
US3369074A (en) * 1965-04-02 1968-02-13 Warwick Electronics Inc Television tube shield and mounting structure

Cited By (10)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3569990A (en) * 1967-03-03 1971-03-09 Thorn Radio Valves And Tubes L Implosion protection apparatus for cathode ray tubes
US3541251A (en) * 1967-09-19 1970-11-17 Standard Elektrik Lorenz Ag Implosion-protecting frame for television picture tubes and process for its installation
US3614519A (en) * 1967-12-18 1971-10-19 Zenith Radio Corp Cathode-ray tube magnetic shield
JPS5743347A (en) * 1980-08-26 1982-03-11 Mitsubishi Electric Corp Cathode ray tube
US4560900A (en) * 1981-08-04 1985-12-24 Tokyo Shibaura Denki Kabushiki Kaisha Cathode ray tube device with electromagnetic shield casing
JPS5851683A (ja) * 1981-09-22 1983-03-26 Mitsubishi Electric Corp 陰極線管装置の製造方法
US4551765A (en) * 1981-10-26 1985-11-05 Allied Corporation Cathode ray tube vibration isolator
US4556821A (en) * 1984-03-15 1985-12-03 Rca Corporation Color image display system having an improved external magnetic shield
DE3608646A1 (de) * 1985-03-20 1986-09-25 Mitsubishi Denki K.K., Tokio/Tokyo Farbbildschirmroehre
DE3616906A1 (de) * 1985-05-20 1986-11-20 Mitsubishi Electric Corp Magnetisches abschirmsystem in einem farbfernsehempfaenger

Also Published As

Publication number Publication date
AT259643B (de) 1968-01-25
GB1146078A (en) 1969-03-19
DE1462832A1 (de) 1968-12-05
CH446433A (de) 1967-11-15
ES327638A1 (es) 1967-08-16
DK117724B (da) 1970-05-25
NL6507304A (en:Method) 1966-12-12
BE682209A (en:Method) 1966-12-07
NO117866B (en:Method) 1969-10-06

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