Magnetic devices
AssigneeScientific Generics Limited
InventorsRobert M. Pettigrew, Stephen H. Chambers, Dafydd G. Davies
Life of this patent
Estimating the term…
Abstract
Magnetic devices are disclosed which include an article comprising a substrate and a thin coating of a magnetic material, in which: (a) said substrate is a flexible, laminar material; (b) said magnetic material is an amorphous metal glass of high intrinsic magnetic permeability, with low or substantially zero magnetostriction, and with low coercivity; and (c) said thin coating of a magnetic material is not greater than 6 microns in thickness. This article can be used as, or to make, an antipilferage tag or marker. Deactivation materials and configurations are also disclosed, as well as techniques, in particular sputtering or PVD, for producing such a tag.
Claims57
An antipilferage tag or marker comprising a substrate and a thin coating of a magnetic material,
- (a) said substrate being a flexible, laminar material generally circular in shape;
- (b) said magnetic material being an amorphous metal glass of high intrinic magnetic permeability, with low or substantially zero magnetostriction, and with low coercivity;
- and
- (c) said thin coating of a magnetic material being no greater than 6 microns in thickness.
An antipilferage tag or marker in the form of a substrate and a thin coating of a magnetic material,:
- (a) said substrate being a flexible, laminar material;
- (b) said magnetic material being an amorphous metal glass of high intrinsic magnetic permeability and with low or substantially zero magnetostriction;
- and
- (c) said thin coating of a magnetic material being no greater than 6 microns in thickness. wherein said tag or marker further comprises a deactivation layer or zone(s) adjacent to or overlying said thin coating.
An antipilferage tag or marker comprising a substrate and a thin coating of a magnetic material,
- (a) said substrate being a flexible, laminar material;
- (b) said magnetic material being an amorphous metal glass of high intrinsic magnetic permeability, with low or substantially zero magnetostriction, and with low coercivity, and
- (c) said thin coating of a magnetic material being no greater than 6 microns in thickness,
- (i) said substrate has a primary axis defining the major dimension of the substrate and a real or notional secondary axis perpendicular to said primary axis and located so as to pass through the mid point of said primary axis;
- and
- (ii) the ratio between the dimensions of said substrate measured along said primary axis and said secondary axis is not greater than 3:1.
An antipilferage tag or marker which comprises a deactivating layer of region comprising a stainless steel which has been cold worked substantially to a hardened state, said steel being an alloy containing, in atomic %, 15-20% chrominum;
- 5-10% nickel;
- carbon up to 0.15%;
- and the balance iron together with incidental impurities present up to a total of 4%.
An antipilferage tag or marker, which comprises a substrate that includes a plurality of acicular elements of magnetic material on said substrate.
An antipilferage tag or marker which comprises a substrate, and a broken or discontinuous flat loop of ferromagnetic material carried by said substrate.
An article for use as an antipilferage marker, comprising:
- an active component of soft magnetic material for generating a signal in an interrogation field applied by a detection system for detecting the article;
- and means for deactivating the active component so that said signal is not generated, or is generated only below a level detectable by the detection system, said deactivating means comprising a plurality of ferromagnetic elements carried by the active component, and each ferromagnetic element acquiring, in the presence of a deactivating magnetic field, north and south magnetic poles at opposite end regions thereof and the ferromagnetic elements being randomly oriented over the surface of the article.
An article for use as an antipilferage marker, comprising:
- an active component of soft magnetic material for generating a signal in an interrogation field applied by a detection system for detecting the article;
- and means for deactivating the active component so that said signal is not generated, or is generated only below a level detectable by the detection system, said deactivating means comprising a layer of mild steel secured to the active component.
An antipilferage tag which comprises a substrate and a thin coating of a magnetic material,:
- (a) said substrate being a flexible, laminar polymer material;
- (b) said magnetic material being an amorphous metal glass of high intrinsic magnetic permeability, with low or substantially zero magnetostriction, and with low coercivity;
- (c) said thin coating of a magnetic material being no greater than 6 microns in thickness;
- (d) said substrate having a primary axis defining the major dimension of the substrate and a real or notional secondary axis perpendicular to said primary axis and located so as to pass through the mid point of said primary axis;
- (e) the ratio between the dimensions of said substrate measured along said primary axis and said secondary axis being no greater than 3:1;
- and
- (f) the tag further including a deactivation layer of zone(s) adjacent to said thin coating.
An antipilferage tag or marker comprising a substrate and a thin coating of a magnetic material,
- a. said substrate being a flexible, laminar material formed of a polyester;
- b. said magnetic material being an amorphous metal glass of high intrinsic magnetic permeability, with low or substantially zero magnetostriction, and with low coercivity;
- and
- c. said thin coating of a magnetic material being no greater than 6 microns in thickness.
An antipilferage tag or marker comprising a substrate and a thin coating of a magnetic material,
- a. said substrate being a flexible, laminar material;
- b. said magnetic material being an amorphous metal glass of high intrinsic magnetic permeability, with low or substantially zero magnetostriction, and with low coercivity;
- and
- c. said thin coating of a magnetic material being no greater than 6 microns in thickness, and being configured as a broken or discontinuous flat loop of ferromagnetic material.
An antipilferage tag or marker comprising a substrate and a thin coating of a magnetic material,
- (a) said substrate being a flexible, laminar material;
- (b) said magnetic material being an amorphous metal glass of high intrinsic magnetic permeability, with low or substantially zero magnetostriction, and with low coercivity;
- and
- (c) said thin coating of a magnetic material being no greater than 6 microns in thickness, and being substantially magnetically isotropic in the plane of the substrate.
An antipilferage tag or marker comprising a substrate and a thin coating of a magnetic material,
- (a) said substrate being a flexible, laminar material;
- (b) said magnetic material being an amorphous metal glass of high intrinsic magnetic permeability, with low or substantially zero magnetostriction, and with low coercivity, and being formed from an alloy containing cobalt and niobium together with a glass-forming element, and
- (c) said thin coating of a magnetic material being no greater than 6 microns in thickness.
An antipilferage tag or marker comprising a substrate and thin coating of a magnetic material,
- (a) said substrate being a flexible, laminar material;
- (b) said magnetic material being an amorphous metal glass of high intrinsic magnetic permeability, with low or substantially zero magnetostriction, and with low coercivity and including an alloy containing cobalt, iron, silicon and boron;
- and
- (c) said thin coating of a magnetic material being no greater than 6 microns in thickness.
Dependencies are inferred from the claim text.