A magnetic storage system includes a magnetic storage medium comprising a keeper layer of relatively low permeability soft magnetic material deposited upon a magnetic storage layer or between multiple magnetic storage layers. The low permeability keeper layer may be disposed either above or below the magnetic storage layer. In the unsaturated state, the keeper layer acts as a shunt path for flux emanating from recorded transitions on the magnetic storage layer, producing an image field of the recorded transitions in the keeper. This shunt path prevents signal flux emanating from the recorded transitions from reaching the head. To read data from a recorded transition on the magnetic storage layer; a bias current is applied to windings of the head, creating a bias flux which saturates a portion of the keeper layer. Once saturated, this portion of the keeper can no longer shunt flux emanating from the recorded transition, which is the region represented by the head reproduce transducer.

Magnetic storage and reproducing system with a low permeability keeper and a self-biased magnetoresitive reproduce head

A data storage device for use as a portable card, magnetically encodeable card, magnetic credit card (100) or the like is shown. The data storage device includes a substrate having at least one surface. A high density, magnetically coercive material layer (110) is disposed on or is deposited on the substrate for storing magnetic signals. The magnetically coercive material may have an axis of magnetization that is oriented in a predetermined direction relative to the at least one surface of the substrate. A layer of non-magnetically material is disposed on the substrate for defining an exchange break layer. A relatively hard, abradeable protective coating is formed on said magnetic material layer and is selected to have a thickness between a maximum thickness which would materially attenuate magnetic signals passing between the magnetic material layer and a transducer and a minimum thickness enabling said protective coating to be abraded by usage in an ambient natural atmosphere operating environment for removing therefrom a known quantity of the protective coating. The protective coating may comprise one, two or more layers of materials.

Data storage device, apparatus and method for using same

The flexible, particulate magnetic storage medium includes a substrate and a magnetic storage layer of hard magnetic particles held within a binder. The flexible, particulate magnetic storage medium also includes a soft magnetic keeper layer. The soft magnetic keeper layer may be established by coating the individual hard magnetic particles of the magnetic storage layer with a layer of soft magnetic material to establish a "keeper layer" around each particle. A break layer of non-magnetic material may be provided between the hard and soft layers. The individual particles are coated by methods such as in situ precipitation. The soft magnetic layer may also be established by providing a separate layer of soft magnetic material within a binder of cross linkable resins. The resulting flexible, particulate magnetic storage medium is a laminate principally comprising a substrate, a first layer of hard magnetic particles within a binder, and a second layer of soft magnetic particles also within a binder. The laminate medium may be produced through extrusion of binder particle mixes through multi aperture slot die extensions. The flexible, particulate magnetic media may be used in tape or flexible disc formats.

Particulate magnetic medium utilizing keeper technology and methods of manufacture

An improved magnetic head (100) obviates the need for separate read and write heads in a magnetic storage system by providing a head core (110) having two physical gaps (112,114) configured to generate a reproduce track width (124) that is narrower than a record track width (122). The core of the head comprises a tapered center pole (130) disposed between two generally symmetrical main poles (102,104) to form physical record and reproduce gaps. A magnetically saturable, high permeability element (150) is disposed within the core in a manner that bridges the rear of the record gap.

Two-gap magnetic read/write head

A magnetic storage system is disclosed that includes a magnetic storage layer (112) associated with a soft magnetic saturable keeper layer (114). A transducer (118) is spaced from the storage layer and the keeper layer in flying relationship thereto, with an MR element (124) contained therein to provide high sensitivity detection along with the reduced spacing loss available from the keepered storage layer.

Improved magnetic recording system having a saturable layer and detection using MR element

Magnetic transducer-keeper combination embodiments of the invention are described. Each has a magnetic core defining a physical gap and a thin magnetic keeper arranged in close proximity of the core to bridge the gap. A magnetic flux from the gap saturates the keeper inan area bridging the gap, thereby forming a signal transducing zone in the keeper. The keeper is maintained stationary and the core moved or scanned with respect to the same, thereby moving or scanning the transducing zone in the keeper.

Beverley R. Gooch

Papers

Method and apparatus using a stationary magnetic body for effecting signal transfers between a moving magnetic core and a magnetic storage medium