Having Multiple Independent Mr Sensors Patents (Class 360/316)
  • Patent number: 6580587
    Abstract: A magnetoresistive (GMR) sensor includes a substrate and a first trilayer disposed on the substrate. A first spacer layer is disposed on the first trilayer. A first magnetic layer is disposed on the first spacer. A second spacer layer is disposed on the first magnetic layer. A second magnetic layer is disposed on the second spacer layer. A third spacer layer is disposed on the second magnetic layer. A second trilayer is disposed on the third spacer layer and a cap layer is disposed on the second trilayer. The first and second trilayers include, a first ferromagnetic layer, a second ferromagnetic layer and an anti-parallel coupling layer disposed between and in contact with the first and second ferromagnetic layers.
    Type: Grant
    Filed: May 17, 2001
    Date of Patent: June 17, 2003
    Assignee: Seagate Technology LLC
    Inventor: Brenda A. Everitt
  • Patent number: 6577469
    Abstract: A variable width flat tape head for bi-directional contact recording and method for making the same has significant advantages over both traditional contoured tape heads and single width flat heads for contact recording applications. The variable width head and process disclosed herein allows for greater ease of manufacturing, efficient layout of the devices on thin film wafers and provides a significant cost reduction in the production of the head compared to traditionally contoured tape heads. In addition, the present invention reduces unnecessary surface area where the tape contacts the head, thus reducing tape wear and damage that is present in single width flat heads (where the tape is in contact uniformly across the tape width), thereby providing a concomitant improvement in tape wear and life.
    Type: Grant
    Filed: April 23, 2002
    Date of Patent: June 10, 2003
    Assignee: Quantum Corporation
    Inventors: James Kennedy, Donna Jean Kaiser
  • Patent number: 6532130
    Abstract: A head (130) for a disk storage device having a plurality of tracks (117) divided into memory cells (234), including a magnetic circuit (205, 230a, 230b, 250a, 250b) for reading the memory cells (234) in succession, the magnetic circuit (205, 230a, 230b, 250a, 250b) for reading the memory cells (234) including at least two partial reading components (206a, 230a, 250a; 206b, 230b, 250b) each for reading a portion (234a; 234b) of each memory cell (234), the portions (234a; 234b) being arranged transversely relative to the longitudinal axis (233) of the corresponding track (117).
    Type: Grant
    Filed: July 16, 1998
    Date of Patent: March 11, 2003
    Assignee: STMicroelectronics, S.r.l.
    Inventors: Bruno Murari, Benedetto Vigna, Paolo Ferrari
  • Publication number: 20030026046
    Abstract: A thin-film includes an inductive element and a first and second magneto-resistive effect elements in which the first and second magneto-resistive effect elements are arranged in proximity to each other on a substrate, and one surface of the substrate perpendicular to the surface formed with the first and second magneto-resistive effect elements constitutes a slider surface, thereby providing appropriate hight of the magneto-resistive effect elements.
    Type: Application
    Filed: December 18, 2001
    Publication date: February 6, 2003
    Applicant: Hitachi, Ltd.
    Inventors: Hideo Yamakura, Toshio Tamura, Koji Tanaka
  • Patent number: 6476993
    Abstract: A compact rotary transformer is disclosed. In the structure of the rotary transformer, a timing-signal producing unit detects a control signal superimposed on an electric power signal output from a power transmission channel of the rotary transformer to produce a timing signal. A head-switching-signal generating unit uses the timing signal to generate a switching signal for performing switching between reproducing heads so that one of the reproducing heads is selected by a switch. A reproduction channel of the rotary transformer outputs a reproducing signal via the switch.
    Type: Grant
    Filed: June 15, 2000
    Date of Patent: November 5, 2002
    Assignee: Sony Corporation
    Inventor: Yoji Aoki
  • Publication number: 20020131217
    Abstract: A multichannel magnetic head using magnetoresistive effect comprises a first magnetic shield and electrode (11), a second magnetic shield and electrode (12), the first and second magnetic shield and electrodes (11), (12) being opposed to each other, and a plurality of magnetoresistive effect type reproducing magnetic head elements arrayed between the first and second magnetic shield and electrodes (11) and (12), wherein the reproducing magnetic head elements formed of ferromagnetic tunnel type magnetoresistive effect elements are arrayed in parallel on at least the first magnetic shield and electrode (11). Electrodes on one side for applying a sense current to these ferromagnetic tunnel type magnetoresistive effect element in the direction crossing a tunnel barrier layer are constructed commonly by the first magnetic shield and led out as a common one terminal and thereby the number of terminals can be decreased.
    Type: Application
    Filed: March 7, 2002
    Publication date: September 19, 2002
    Applicant: Sony Corporation
    Inventors: Eiji Nakashio, Seiji Onoe, Junichi Sugawara
  • Patent number: 6344951
    Abstract: Height setting processing performed while measuring DC resistance of a monitor element formed on a substrate causes smearing (sag) in shielding layers formed above and below the monitor element with gap layers held therebetween, causing a short circuit between the monitor element and the shielding layers due to smearing. A recessed portion is formed in a lower shielding layer formed on the substrate, and an insulating layer is formed in the recessed portion. The monitor element is formed on the insulating layer with a lower gap layer formed therebetween. The formation of the insulating layer increases the distance between the monitor element and the lower shielding layer, thereby preventing electrical connection even when smearing occurs in the lower shielding layer. Alternatively, the monitor element is formed on the substrate with the lower gap layer formed therebetween, and the lower shielding layer formed below magnetoresistive elements is not formed below the monitor element.
    Type: Grant
    Filed: December 7, 1999
    Date of Patent: February 5, 2002
    Assignee: Alps Electric Co., Ltd.
    Inventors: Kiyoshi Sato, Katsuya Sugai
  • Publication number: 20020012204
    Abstract: Herein is disclosed a method and apparatus for controlling a lapping process, so as to create a read/write head that contains a primary magnetoresistive read element with a desired stripe height. An improved lapping guide is achieved by incorporating a secondary magnetoresistive element into a read/write head. By virtue of its location on the same read/write head as a primary magnetoresistive element (used for reading data during operation of the disc drive), the secondary element is located in close proximity to the primary element, resulting in smaller tolerances in aligning or relating the top edges of the primary and secondary elements. Accordingly, the secondary magnetoresistive element more reliably serves as a proxy for the primary element. Optionally, the secondary magnetoresistive element may be fashioned with identical dimensions as the primary element, so as to render the secondary element equivalent to the primary element with regard to magnetic sensitivity.
    Type: Application
    Filed: May 25, 2001
    Publication date: January 31, 2002
    Inventors: Zine-Eddine Boutaghou, Edward Stephens Murdock
  • Patent number: 6330123
    Abstract: A tape servo system includes tape having bands of tracks including at least one data band having a plurality of data tracks of track pitch P and a servo band dedicated for servo information. The servo band includes two or more noncontiguous servo tracks with each pair of adjacent servo tracks of the two or more noncontiguous servo tracks having a center to center separation equal to M*P, wherein M for each pair of adjacent servo tracks may be any integer≧2. The system may further include a head assembly having a single magnetoresistive read element tapped to provide at least (K+1) tapped servo read elements for use in reading servo information written to the servo band; wherein K is equal to the integer M for the pair of adjacent servo tracks having the greatest center to center separation and a repositioning assembly for repositioning the head assembly as a function of the servo information.
    Type: Grant
    Filed: May 19, 2000
    Date of Patent: December 11, 2001
    Assignee: Imation Corp.
    Inventors: Theodore A. Schwarz, Robert J. Youngquist, Hung T. Tran
  • Patent number: 6317302
    Abstract: A thin-film magnetic read head device comprises an end face extending in a first direction, in which a magnetic information carrier is movable with respect to the magnetic head device, and in a second direction, perpendicular to said first direction. The magnetic head device further comprises a multilayer structure with at least two soft-magnetic layers separated by a magnetic insulation layer and with at least one exchange biasing layer, which multilayer structure extends in the second direction and in a third direction, perpendicular to the first and the second direction, and forms at least one flux path in the first and the third direction. The exchange coupling between one of the soft-magnetic layers and the exchange biasing layer is at least partly reduced locally, i.e. interrupted or at least substantially reduced, in at least the second direction, while the exchange biasing layer extends uninterruptedly in the region of said reductions.
    Type: Grant
    Filed: August 2, 1999
    Date of Patent: November 13, 2001
    Assignee: U.S. Philips Corporation
    Inventors: Hans W. Van Kesteren, Derk J. Adelerhof, Reinder Coehoorn
  • Publication number: 20010036042
    Abstract: A plurality of magnetoresistive heads are arranged on a wafer substrate. A plurality of electrode pads are arranged on the wafer substrate in a first direction. Each electrode pad is connected to an associated magnetoresistive head. Respective adjacent electrode pads are shifted from each other in a second direction perpendicular to the first direction. The shifted amount of the adjacent pads in the second direction is larger than a dimension of the electrode pad in the second direction.
    Type: Application
    Filed: April 25, 2001
    Publication date: November 1, 2001
    Inventors: Satoshi Ajiki, Hiroaki Tobitsuka, Koichi Hosoya
  • Patent number: 6307721
    Abstract: A magnetoresistive (MR) sensor element and a method for fabricating the magnetoresistive (MR) sensor element. There is first provided a substrate. There is then formed over the substrate a first shield layer. There is then formed upon the first shield layer a first dielectric spacer layer. There is then formed upon the first dielectric spacer layer a patterned magnetoresistive (MR) layer. There is then formed adjacent to and electrically communicating with a pair of opposite ends of the patterned magnetoresistive (MR) layer a pair of patterned conductor lead layers to define a trackwidth of the patterned magnetoresistive (MR) layer. There is then formed upon the pair of patterned conductor lead layers and upon the patterned magnetoresistive (MR) layer at the trackwidth of the patterned magnetoresistive (MR) layer a blanket second dielectric spacer layer.
    Type: Grant
    Filed: September 4, 1998
    Date of Patent: October 23, 2001
    Assignee: Headway Technologies, Inc.
    Inventors: Mao-Min Chen, Cherng-Chyi Han, Cheng T. Horng
  • Patent number: 6295718
    Abstract: Within a method for forming a magnetoresistive (MR) sensor element there is first provided a substrate. There is then formed over the substrate a first magnetoresistive (MR) layer having formed contacting the first magnetoresistive (MR) layer a magnetically biased first magnetic bias layer biased in a first magnetic bias direction with a first magnetic bias field strength. There is also formed separated from the first magnetoresistive (MR) layer by a spacer layer a second magnetoresistive (MR) layer having formed contacting the second magnetoresistive (MR) layer a magnetically un-biased second magnetic bias layer.
    Type: Grant
    Filed: August 16, 1999
    Date of Patent: October 2, 2001
    Assignee: Headway Technologies, Inc.
    Inventors: Min Li, Simon H. Liao
  • Patent number: 6282067
    Abstract: A magnetoresistive effect element 5 is physically configured such that the element width is at least three times as large as the element height. A plurality of domain control layers 11 to 13 are located between the magnetoresistive effect element 5 and a plurality of detecting electrodes 8 to 10 in a state that the domain control layers 11 to 13 are closely formed on the magnetoresistive effect element 5. Each of the domain control layers 11 to 13 applies a unidirectional magnetic field to a region of the magnetoresistive effect element 5 vertically disposed in a guard band of the magnetic recording medium 4, the guard band having no information recorded therein. The unidirectional magnetic field is directed in an orientation of an initial magnetization in a single magnetoresistive effect element, the orientation of which depends on a direction of on an easy axis of the magnetoresistive effect element 5.
    Type: Grant
    Filed: September 20, 1999
    Date of Patent: August 28, 2001
    Assignees: Nippon Hoso Kyokai, Pioneer Corporation
    Inventors: Kenji Machida, Naoto Hayashi, Yoshiro Yoneda, Junji Numazawa, Makiko Kohro, Takahisa Tanabe, Shinichi Nagahara
  • Patent number: 6104562
    Abstract: In a rotating magnetic disk storage device which uses an imbedded servo pattern for positioning an actuator, each transducer head comprises two magnetoresistive read elements, the read elements being separated by an insulating layer. The read elements are of different widths, the narrower element being used to read data, and the wider element being used to read servo patterns which locate the track centerline. The read elements are preferably deposited in layers on the rear of the slider body, with a thin-film inductive write head deposited in layers over the read elements. Preferably, the read elements are connected to three lead wires: a common ground lead, and separate sense leads. The sense amplification electronics alternatively sense resistance changes in one element or the other as the head passes over data or servo patterns. Because the narrow read element is used for reading data, noise due to reading too close to the edge of the track can be reduced.
    Type: Grant
    Filed: April 3, 1997
    Date of Patent: August 15, 2000
    Assignee: International Business Machines Corporation
    Inventors: Hal Hjalmar Ottesen, Gordon James Smith
  • Patent number: 4946629
    Abstract: (i) A compound of the formula: ##STR1## wherein R is H, a metal or a group containing a tetravalent N atom;X is ##STR2## R.sup.1 is NO.sub.2, CN or COOY; Y is H, C.sub.1-4 -alkyl, a metal or a group containing a tetravalent N atom;R.sup.2 & R.sup.3 are each independently H or a non-hydrophilic aliphatic or cycloaliphatic group containing up to 30 carbon atoms;R.sup.4 & R.sup.5 are each independently H or a non-hydrophilic aliphatic or cycloaliphatic group containing up to 30 carbon atoms;and R.sup.6 & R.sup.7 are each independently H or a non-hydrophilic group containing up to 4 carbon atoms;or R.sup.4 & R.sup.6 together comprise ring fused to Ring A and R.sup.5 & R.sup.7 are as hereinbefore defined;or R.sup.5 & R.sup.7 together comprise ring fused to Ring A and R.sup.4 & R.sup.6 are as hereinbefore defined;or R.sup.2 & R.sup.4 together with the N atom to which R.sup.2 is attached from a ring fused to Ring A and R.sup.3 & R.sup.5 are as hereinbefore defined;or R.sup.3 & R.sup.
    Type: Grant
    Filed: November 25, 1988
    Date of Patent: August 7, 1990
    Assignee: Imperial Chemical Industries, Plc
    Inventors: Simon Allen, Paul F. Gordon, Richard A. Hann