公开(公告)号：BG61541B1

公开(公告)日：1997-11-28

申请号：BG9987595

申请日：1995-08-18

Applicant: IBM

Inventor： DOVEK MORIS MUSA ,  FOSTER JOHN STUART ,  LAM DONALD K F ,  SAWATZKY ERICH

IPC: G11B5/02 ,  G11B5/00 ,  G11B5/012 ,  G11B5/035 ,  G11B5/09 ,  G11B5/31 ,  G11B5/39 ,  G11B5/58 ,  G11B5/60 ,  G11B20/10

Abstract: The device has a hard magnetic carrier and a magnetic resistance (MR) sensor for reading data recorded on the disk is used. The disk device can be of the type operating with a contact recording with liquid resting, the MR sensor being fitted to the resting end of a carrier running over the liquid resting layer. The operation of the device is improved by including facilities for the minimization of the modulation effect of the basic signal for reading. The modulation is caused by the alternating cooling of the thermosensitive and raising MR sensor in comparison with the disk, depending on the temperature, the temperature change being directly connected to the change of distance between the head and the disk, as a result of the disk ondulations. A filter for removing the modulation can be included in the circuit of the disk device for processing the already read signal, and the MR sensor can be made in such a way that it operates under specified parameters in order to minimize the effect of the basic modulation. The sector of the carrier which is in contact with the disk surface can be selected to have a length smaller than the period of the disk ondulations so that it may follow more closely the topography of the disk surface.

公开(公告)号：AU1788295A

公开(公告)日：1996-05-09

申请号：AU1788295

申请日：1995-05-04

Applicant: IBM

Inventor： DOVEK MORIS MUSA ,  FONTANA ROBERT EDWARD JR ,  SPERIOSU VIRGIL SIMON ,  SPONG JAQUELIN KETNER

IPC: G01R33/09 ,  H01L43/08

Abstract: A magnetic field sensor (10) uses four individual magnetoresistive spin valve elements (A,B,C,D) electrically connected in a bridge circuit. The spin valve elements (A,B,C,D) are lithographically formed on the same substrate with their free layers (36) having their magnetization axes parallel to one another. An electrically conductive fixing layer is formed on the substrate but is insulated from the spin valve elements. The application of current through the fixing conductor during fabrication of the field sensor fixes the direction of magnetization of two of the pinned layers (39) to be antiparallel to the direction of magnetization of the other two pinned layers (39). The bridge circuit (10) output voltage is responsive to an external magnetic field (4) in the plane of the sensor (10). By appropriate fixing of the direction of magnetization of the pinned layers (39) during sensor (10) fabrication, and appropriate connection to the input (20,22) and output leads (24,26), the bridge circuit output voltage is a measure of either the magnetic field or field gradient.

公开(公告)号：HU9502416D0

公开(公告)日：1995-10-30

申请号：HU9502416

申请日：1993-11-24

Applicant: IBM

Inventor： DOVEK MORIS MUSA ,  FOSTER JOHN STUART ,  LAM DONALD K F ,  SAWATZKY ERICH

IPC: G11B5/02 ,  G11B5/00 ,  G11B5/012 ,  G11B5/035 ,  G11B5/09 ,  G11B5/31 ,  G11B5/39 ,  G11B5/58 ,  G11B5/60 ,  G11B20/10

Abstract: A contact magnetic recording rigid disk file utilizes a magnetoresistive (MR) sensor for reading data recorded on the disk. The disk file may be of the liquid-bearing type of contact recording with the MR sensor supported on the trailing end of a carrier which rides on the liquid bearing. The performance of the disk file is enhanced by including means for minimizing the effect of a discovered baseline read signal modulation. The modulation has been determined to be caused by variable cooling of the temperature-sensitive and temperature-elevated MR sensor by the disk, with the temperature variation being directly related to the variation in head-disk spacing caused by the waviness of the surface of the disk. A filter may be incorporated into the read signal processing circuitry of the disk file to eliminate the modulation, the MR sensor may be designed to operate at selected parameters to minimize the effect of the baseline modulation, and the portion of the carrier in contact with the disk surface may be selected to have a length less than the period of the disk waviness so that it more closely follows the disk surface topography.