Browse Prior Art Database

Nonlinear Magnetoresistive Head

IP.com Disclosure Number: IPCOM000081076D
Original Publication Date: 1974-Mar-01
Included in the Prior Art Database: 2005-Feb-27
Document File: 3 page(s) / 42K

Publishing Venue

IBM

Related People

Bajorek, CH: AUTHOR [+2]

Abstract

A magnetoresistive reading head has been designed for low-density applications. It features an unbiased quadratic mode of operation to suppress noise an optimum saturation point to base signal detection and provides a constant output, and an optimum combination of shape and induced uniaxial anisotropies to maximize the output signal of the head.

This text was extracted from a PDF file.
At least one non-text object (such as an image or picture) has been suppressed.
This is the abbreviated version, containing approximately 53% of the total text.

Page 1 of 3

Nonlinear Magnetoresistive Head

A magnetoresistive reading head has been designed for low-density applications. It features an unbiased quadratic mode of operation to suppress noise an optimum saturation point to base signal detection and provides a constant output, and an optimum combination of shape and induced uniaxial anisotropies to maximize the output signal of the head.

A magnetoresistive (MR) element 2 serves as a member, whose resistance changes with the magnetic field it senses that emanates from the magnetized surface of tape 4. Electrical leads 6 convey this change of resistance to a suitable meter, not shown. The plot of change of resistance with magnetic field of the MR element is shown in Figs. 2 and 3. Prior art recording heads employing a magnetoresistive element for sensing have been conceived for high- bit density applications. At such densities, the fields available from the storage medium are weak, in comparison with the fields required to saturate an unbiased magnetoresistor of realistic dimensions. To make such sensors usable it is necessary to maximize their sensitivity by: 1) applying a constant magnetic field to bias them about the inflection point of their R vs. H response curve, and 2) minimizing both their shape and induced uniaxial anisotropies.

In low-bit density applications, the fields available from the storage medium are typically far larger than the field required to saturate a sensor of the aforementioned characteristics. Consequently, the biased mode of operation with a low-saturation point results in unsymmetrical and very sharp signals, as depicted in Fig. 2. Such shapes are inconsistent with reliable signal detection, and the sharp response of the sensor accentuates small noise fields relative to the sig...