International Business Machines Corporation

Other

Frank B Shelledy

George W Brock

Joseph Adam Aboaf

James Lamar Nix

Vincent N Kahwaty

Robert N Hyland

Edward Joseph Pawlowski

Neil L Robinson

Richard F Thornley

Peter Thomas Marino

Edmond W Smathers

John A Barkley

Arthur B Wills

Sidney H Smith

A soft film biased magnetoresistive sensor (10) is fabricated to have reduced Barkhausen noise. The magnetic ratio of the film layers (14 and 18) is controlled to be in the range of 1.7 to 1.95 and the optimum bias point is controlled to be in the range of 35 and 41 degrees.

Very low noise magnetoresistive sensor for high density media

A magnetic head assembly useful as a write head is formed with a ferrite substrate, having a recessed channel on one surface in which a conductive coil is deposited, and a ferrite closure having a planar surface that is joined to the substrate surface to establish a transducing gap and to enclose the recessed coil. In operation, pulsed write current is applied to the write head and a significant reduction in Joule heating is realized. A low resistance substrate is employed to provide a high saturation flux density.

Magnetic head assembly

A magnetic head assembly for cooperating with a relatively moving medium, on which servo information and data information is recorded, and for reading and/or writing on said medium and for erasing said medium is fabricated so that the effect of pickup interference or unwanted signals during playback is reduced. The magnetic head assembly incorporates a geometry which shifts the signal envelope of the interfering signal so that it is in phase with the signal envelope of the desired signal. The preferred geometry is to dimension the head core so that the distance between two gaps or between a single gap and the edge of the core is equal to the distance between the servo tracks on said medium. Additionally, the gap of the head has a gap null occurring at the frequency of the interfering signal.

Minor bit reduction on a magnetic head

Write windings are deposited on a ferrite half yoke mounted on a titanium body, and magnetoresistive elements are deposited on another ferrite half yoke mounted on another titanium body. A center section comprising a sandwich of silver-copper shielding material between two ferrite sheets has glass-filled slots cut on one side thereof. The center shield is placed between the write and read sides with the write windings placed between pairs of glass-filled slots and with the magnetoresistive elements in contact with the opposite surface of the center shield. The write windings and the magnetoresistive elements are connected to connector blocks prior to final assembly, and the write and read sides and the center section are pressured together by bolts through two end pieces, forming a vise-like structure.

Process for making a read-while-write tape head and the product made

This magnetic head construction includes two or more elements defining a transducing gap which are positioned and held together within a shell by a wedge. The magnetic head assembly disclosed normally includes a shell structure, a pair of transducer elements defining a transducing gap, a wedge and a wedge follower. The wedge follower may be present as either a separate element or as a surface carried by one of the transducer elements. The assembly is normally formed by the process of disposing the transducer elements, and the wedge follower, if present, within the shell wall, and then rough positioning these elements within the shell, followed by the insertion of the wedge against the wedge following surface to bring the parts into final position in a locked relationship. Generally speaking, locking is achieved by selecting the wedge angle, .theta. as a function of the coefficients of friction of the mating surfaces according to given formulae. This head structure and process requires no additional adhesive, glass, or other material to lock the parts of the structure together.

Magnetic head housing with wedge locking means

A magnetic transducer exhibiting the magnetoresistive (MR) effect is made by depositing at least two thin film layers. An MR film placed in electrical contact with a higher resistivity layer is magnetically biased by a portion of the MR sense current shunted through the nonmagnetic layer.

Method for manufacturing and using an internally biased magnetoresistive

A magnetoresistive (MR) layer is placed offcenter the distance between two shields to enhance self-biasing. Information is carried on a magnetizable medium as recorded magnetic areas. The shields are spaced apart by a distance on the order of and less than the shortest recorded wavelength for which the head is meant to be used. The MR element and the shields have their edges nearest the medium in a common plane perpendicular to the vertical component of a signal from the recorded area. An additional shunt bias layer may be provided immediately adjacent and coextensive the MR element, and the head may serve one or many tracks.

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Longmont, CO, United States of America

Frank B Shelledy