Unitika Ltd.

Isamu Ogasawara

Shinji Furukawa

Toshiyuki Hirano

Hiroyuki Tomioka

Shuji Ueno

Kiyotsugu Maekawa

Nobuyoshi Yano

Kazuki Oka

Kenji Amiya

Kenichi Bushida

Katsuhiro Kawashima

An Fe group-based amorphous alloy ribbon having a cross section having a width of from 100 to 900 &mgr;m and a thickness of from 8 to 50 &mgr;m and a magnetic hysteresis loop which exhibits a large Barkhausen discontinuity. The amorphous alloy ribbon is suitable for preparing magnetic markers for use in an anti-theft system and an article surveillance system, and as a pulse generator. A magnetic marker formed from the amorphous alloy ribbon is also disclosed.

Fe group-based amorphous alloy ribbon and magnetic marker

A magnetic sensor device comprising a magnetic element and a wire wound around the magnetic element. The magnetic element has a cross-sectional area of not more than 0.55 mm.sup.2 and a saturation magnetostriction constant .lambda.s whose absolute value is smaller than 1.times.10.sup.-6, with Sw/Sm being equal to or smaller than 9, provided that Sw is the cross-sectional area of the wire and Sm is the cross-sectional area of the magnetic element. Preferably, the magnetic element has an elastic limit .sigma.m greater than 1,000 MPa, and the elongation the magnetic element experiences upon application of a stress equal to the elastic limit .sigma.m is between 1.0% and 5.0%. It is also preferable that the magnetic element and the wire are covered with a resin layer to form an integral unit.

Miniature magnetic sensor device using an inductor device

A magnetic marker of the present invention includes a magnetic thin wire for generating pulses and bodies of soft magnetic materials that are arranged close to the two ends of the thin wire that have a smaller coercive force than the magnetic thin wire. The magnetic thin wire has a diameter of 60-115 .mu.m and has a ratio of B.sub.r /B.sub.s of a B-H loop of 0.8 or more. Thus, a small magnetic marker can be formed which provides a large Barkhausen effect even if it contains a very short magnetic thin wire.

Magnetic marker

A compact and superior magnetic marker for an electronics apparatus for surveillance of article comprises at one or more wire members and a plane member contacting substantially directly to each other. An angle of the magnetic easy axis of the plane member relative to the longitudinal direction of the wire member is between 40.degree. and 90.degree. to show large Barkhausen reversal. An influence of demagnetizing field can be reduced by using the simple structure. The magnetic marker can be produced continuously at a low cost.

Magnetic marker and manufacturing method therefor

A fine amorphous metallic wire having a circular cross section and stability to a bias magnetic field, said wire being composed of an alloy having the following composition formula

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Otsu, Japan

Isamu Ogasawara