Global Patent Index - EP 0269498 A1

EP 0269498 A1 19880601 - Earth-magnetic field protection device for cathode ray tubes with a shadow mask.

Title (en)

Earth-magnetic field protection device for cathode ray tubes with a shadow mask.

Title (de)

Vorrichtung zur Abschirmung von Kathodestrahlröhren mit Masken gegenüber dem Endmagnetfeld.

Title (fr)

Dispositif de protection de tubes cathodiques à masque vis-à-vis du champ magnétique terrestre.

Publication

EP 0269498 A1 19880601 (FR)

Application

EP 87402473 A 19871103

Priority

FR 8615578 A 19861107

Abstract (en)

[origin: EP0269498B1] 1. A device for the protection of cathode ray tubes with a mask and with a shielding screen of a material with a low magnetic permeability, with respect to the terrestrial magnetic field, comprising a demagnetizing coil of the type with two loops (10 and 11) of oblong form, whose major sides (12, 13, 16 and 17) are placed substantially horizontally, said two loops being secured to a substantial extent on the cone (3) of the cathode ray tube, symmetrically with respect to a plane passing along the axis of the neck (4) of the tube and connected by a device generating a demagnetizing current, characterized in that the two major sides of these loops furthest removed from each other (16 and 17) are located to the fore of the sintering plane (5) of the tube.

Abstract (fr)

Pour améliorer l'effet de blindage de tube cathodique trichrome conféré par l'ensemble cadre-masque et par un écran de blindage en matériau à faible perméabilité magnétique, on fait passer les brins extérieurs (16, 17) d'une bobine de démagnétisation à deux boucles en avant des oreilles de fixation (7) et non pas en arrière du plan de frit (5) comme c'était le cas antérieurement, et on règle la position des brins intérieurs (12, 13) pour obtenir le meilleur compromis.

IPC 1-7

H01J 29/00

IPC 8 full level

H01J 29/00 (2006.01)

CPC (source: EP US)

H01J 29/003 (2013.01 - EP US); H01J 2229/003 (2013.01 - EP US); H01J 2229/0053 (2013.01 - EP US)

Citation (search report)

Designated contracting state (EPC)

DE IT NL

DOCDB simple family (publication)

EP 0269498 A1 19880601; EP 0269498 B1 19900905; DE 3764776 D1 19901011; FR 2606574 A1 19880513; FR 2606574 B1 19890113; US 4940920 A 19900710

DOCDB simple family (application)

EP 87402473 A 19871103; DE 3764776 T 19871103; FR 8615578 A 19861107; US 11751187 A 19871106