EP0269498B1 - Vorrichtung zur Abschirmung von Kathodestrahlröhren mit Masken gegenüber dem Endmagnetfeld - Google Patents

Vorrichtung zur Abschirmung von Kathodestrahlröhren mit Masken gegenüber dem Endmagnetfeld Download PDF

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Publication number
EP0269498B1
EP0269498B1 EP87402473A EP87402473A EP0269498B1 EP 0269498 B1 EP0269498 B1 EP 0269498B1 EP 87402473 A EP87402473 A EP 87402473A EP 87402473 A EP87402473 A EP 87402473A EP 0269498 B1 EP0269498 B1 EP 0269498B1
Authority
EP
European Patent Office
Prior art keywords
tube
loops
cathode ray
major sides
plane
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
EP87402473A
Other languages
English (en)
French (fr)
Other versions
EP0269498A1 (de
Inventor
Guiseppe Giannantonio
Cesare De Paolis
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.)
Videocolor SA
Original Assignee
Videocolor SA
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 Videocolor SA filed Critical Videocolor SA
Publication of EP0269498A1 publication Critical patent/EP0269498A1/de
Application granted granted Critical
Publication of EP0269498B1 publication Critical patent/EP0269498B1/de
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
    • H01J29/003—Arrangements for eliminating unwanted electromagnetic effects, e.g. demagnetisation arrangements, shielding coils
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01J—ELECTRIC DISCHARGE TUBES OR DISCHARGE LAMPS
    • H01J2229/00—Details of cathode ray tubes or electron beam tubes
    • H01J2229/0007—Elimination of unwanted or stray electromagnetic effects
    • H01J2229/003—Preventing or cancelling fields entering the enclosure
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01J—ELECTRIC DISCHARGE TUBES OR DISCHARGE LAMPS
    • H01J2229/00—Details of cathode ray tubes or electron beam tubes
    • H01J2229/0007—Elimination of unwanted or stray electromagnetic effects
    • H01J2229/0046—Preventing or cancelling fields within the enclosure
    • H01J2229/0053—Demagnetisation

Definitions

  • the Earth's magnetic field acts on the path of the electron beams emitted by the barrel of a cathode ray tube and can cause what is called in a trichrome tube a "loss of register", that is to say -to say an offset of the impact on the screen of the beams of the three fundamental colors compared to the corresponding phosphors.
  • the amplitude of the parasitic deviation depends on the amplitude of the terrestrial magnetic field, but also on the geometry of the tube (distance gun-mask, parameter called "p”, and distance mask-slab, parameter called "q").
  • This demagnetization makes it possible to locate the magnetization curve on the so-called anhysteresis curve, and thus to obtain a magnetic field of opposition to the more intense terrestrial field, hence better shielding.
  • This demagnetization is conventionally carried out using a coil fixed to the rear of the tube, on the cone.

Landscapes

  • Physics & Mathematics (AREA)
  • Electromagnetism (AREA)
  • Vessels, Lead-In Wires, Accessory Apparatuses For Cathode-Ray Tubes (AREA)
  • Video Image Reproduction Devices For Color Tv Systems (AREA)

Claims (4)

1. Schutzvorrichtung für Kathodenstrahlröhren mit Maske und Abschirmung aus einem Material mit geringer magnetischer Permeabilität gegenüber dem Erdmagnetfeld, die eine Entmagnetisierungsspule vom Typ mit zwei Schleifen (10, 11) von länglicher Form umfaßt, deren Längsseiten (12, 13, 16, 17) etwa horizontal angeordnet sind, wobei diese beiden Schleifen zum Großteil auf dem Kegel (3) der Kathodenstrahlröhre symmetrisch in Bezug auf eine Ebene befestigt sind, die durch die Achse des Röhrenhalses (4) verläuft, und mit einer stromerzeugen- <-. Vorrichtung zur Entmagnetisierung verbunden Siild, dadurch gekennzeichnet, daß die beiden am weitesten voneinander entfernten Längsseiten (16, 17) dieser Schleifen vor der Sinter-Ebene (5) der Röhre angeordnet sind.
2. Vorrichtung nach Anspruch 1, dadurch gekennzeichnet, daß die vorerwähnten beiden Längsseiten (16, 17) nahe der Längsachse des Antiimplosionsgürtels der Röhre (6) angeordnet sind.
3. Vorrichtung nach Anspruch 2, für Kathodenstrahlröhren mit Befestigungsösen (7), die am Antiimplosionsgürtel auf mittlerer Breite dieses Gürtels angebracht sind, dadurch gekennzeichnet, daß die vorerwähnten beiden Längsseiten (16, 17) zwischen der Befestigungsebene der Ösen und der Verbindungsebene der Ummantelung mit der Bildschirmplatte verlaufen.
4. Vorrichtung nach einem der vorausgehenden Ansprüche, dadurch gekennzeichnet, daß die beiden einander am nächsten liegenden Längsseiten dieser Schleifen (12, 13) etwa auf halbem Wege zwischen der vorderen Seite der Ablenkspule (8) und dem Anodenknopf (23) oder seinem dazu symmetrischen (23A) Punkt angeordnet sind.
EP87402473A 1986-11-07 1987-11-03 Vorrichtung zur Abschirmung von Kathodestrahlröhren mit Masken gegenüber dem Endmagnetfeld Expired - Lifetime EP0269498B1 (de)

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
FR8615578 1986-11-07
FR8615578A FR2606574B1 (fr) 1986-11-07 1986-11-07 Dispositif de protection de tubes cathodiques a masque vis-a-vis du champ magnetique terrestre

Publications (2)

Publication Number Publication Date
EP0269498A1 EP0269498A1 (de) 1988-06-01
EP0269498B1 true EP0269498B1 (de) 1990-09-05

Family

ID=9340653

Family Applications (1)

Application Number Title Priority Date Filing Date
EP87402473A Expired - Lifetime EP0269498B1 (de) 1986-11-07 1987-11-03 Vorrichtung zur Abschirmung von Kathodestrahlröhren mit Masken gegenüber dem Endmagnetfeld

Country Status (4)

Country Link
US (1) US4940920A (de)
EP (1) EP0269498B1 (de)
DE (1) DE3764776D1 (de)
FR (1) FR2606574B1 (de)

Families Citing this family (10)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US5350973A (en) * 1989-08-31 1994-09-27 Kabushiki Kaisha Toshiba Cathode-ray tube apparatus having a reduced leak of magnetic fluxes
IT1251351B (it) * 1990-06-25 1995-05-08 Videocolor Spa Apparecchio per la compensazione di campi magnetici
US5107179A (en) * 1990-10-22 1992-04-21 Sun Microsystems, Inc. Method and apparatus for magnetic field suppression using inductive resonant and non-resonant passive loops
US5229689A (en) * 1991-05-14 1993-07-20 Apple Computer, Inc. Electrostatic shield for nearfield alternating electrical field emission reduction in a CRT display
JPH0541176A (ja) * 1991-08-07 1993-02-19 Sony Corp 陰極線管
JP3112317B2 (ja) * 1991-10-09 2000-11-27 ソニー株式会社 陰極線管の消磁コイル
US5347367A (en) * 1993-05-03 1994-09-13 Thomson Consumer Electronics, Inc. Cathode-ray tube having implosion protection means with openings
ATE192882T1 (de) * 1994-10-21 2000-05-15 Koninkl Philips Electronics Nv Farbbildanzeigevorrichtung mit farbbildröhre und entmagnetisierungsvorrichtung
US5815361A (en) * 1995-04-03 1998-09-29 Samsung Electronics Co., Ltd. Magnetic field shielding device in display
SG93282A1 (en) * 1997-01-29 2002-12-17 Sony Corp Heat shrink band steel sheet and manufacturing method thereof

Family Cites Families (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3879633A (en) * 1963-12-19 1975-04-22 Rca Corp Television degaussing system with saddle-type coils adjacent CRT cone
NL6515107A (de) * 1965-11-20 1967-05-22
US3872347A (en) * 1972-04-14 1975-03-18 Tokyo Shibaura Electric Co Degaussing device for colour cathode ray tubes
NL167289C (nl) * 1973-09-13 1981-11-16 Philips Nv Kleurentelevisieweergeefinrichting voorzien van een kleurentelevisiebeeldbuis en een ontmagnetiserings- inrichting.

Also Published As

Publication number Publication date
US4940920A (en) 1990-07-10
FR2606574A1 (fr) 1988-05-13
FR2606574B1 (fr) 1989-01-13
EP0269498A1 (de) 1988-06-01
DE3764776D1 (de) 1990-10-11

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