Ampex Corporation

Thomas M Coughlin

Beverley R Gooch

David H Davies

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

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

Magnetic recording system having a saturable layer and detection using

A magnetic storage medium comprises a keeper layer of soft magnetic, saturable material disposed upon a magnetic storage layer. The keeper layer is disposed above the magnetic storage layer, and a non-magnetic 'break' layer may be used between the keeper and the storage layer to reduce the exchange coupling between these layers. To increase the ability of the keeper layer to shunt flux from the magnetic storage layer, a longitudinal anisotropy is induced in the keeper layer. This establishes a desired magnetic orientation of the keeper which facilitates maintaining the regularity (i.e., relative uniformity) of the transitions, and reducing the magnetic interaction between transitions as the spacing between transitions is reduced to provide denser media. Specifically, the longitudinal anisotropy may be oriented either circumferentially or radially relative to the plane of rotation of the magnetic storage layer.

Method and apparatus for providing a magnetic storage and reproducing

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

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.

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Atascadero, CA, United States of America

Thomas M Coughlin