Magnetoresistive Patents (Class 365/8)
  • Patent number: 10937949
    Abstract: Disclosed is a method of forming a doughnut-shaped skyrmion, the method including heating a local area of a vertical magnetic thin film magnetized in a first direction, which is any one of an upward direction and a downward direction, applying a magnetic field having a second direction, which is opposite the first direction, and having intensity higher than coercive force of the vertical magnetic thin film to the vertical magnetic thin film to form a first area magnetized in the second direction, applying a magnetic field having the second direction to the vertical magnetic thin film to form a second area, which is an extension of the first area, and applying a magnetic field having the first direction to the vertical magnetic thin film to form a third area magnetized in the first direction in the second area.
    Type: Grant
    Filed: October 16, 2019
    Date of Patent: March 2, 2021
    Inventors: Kyoung-Woong Moon, Chan Yong Hwang
  • Patent number: 9859017
    Abstract: To provide a magnetic element capable of performing skyrmion transfer, a skyrmion memory to which this magnetic element is applied, and a shift register, for example, a magnetic element capable of performing skyrmion transfer is provided, the magnetic element providing a transverse transfer arrangement in which the skyrmion is transferred substantially perpendicular to a current between an upstream electrode and a downstream electrode, and including a plurality of stable positions in which the skyrmion exists more stably than in other regions of a magnet, and a skyrmion sensor that detects a position of the skyrmion.
    Type: Grant
    Filed: March 5, 2017
    Date of Patent: January 2, 2018
    Assignee: RIKEN
    Inventors: Naoto Nagaosa, Wataru Koshibae, Junichi Iwasaki, Masashi Kawasaki, Yoshinori Tokura, Yoshio Kaneko
  • Patent number: 9773540
    Abstract: A method for generating a skyrmion, comprising: depositing a vertical metallic nanopillar electrode on a first side of a helimagnetic thin film, the helimagnetic thin film having a contact on a second side to provide a current drain; injecting a current through the vertical metallic nanopillar electrode to generate a rotating field; and applying a static upward magnetic field perpendicular to the helimagnetic thin film to maintain an FM phase background.
    Type: Grant
    Filed: July 18, 2016
    Date of Patent: September 26, 2017
    Assignee: THE JOHNS HOPKINS UNIVERSITY
    Inventors: Jiadong Zang, Chia-Ling Chien, Yufan Li, Roger K. Lake, Gen Yin
  • Patent number: 9741420
    Abstract: A skyrmion driving method that utilizes electric current to make it possible to perform driving ON-OFF control at high speed and to suppress the influence of an inertial effect so that the driving control can be performed further logically. The skyrmion is driven based on a driving amount proportional to a time-integrated value of an electric current density j(t) (Am?2) at a clock time t for a location R(t) of the skyrmion at the clock time t and on a driving amount that is in accordance with a diffusive motion due to thermal fluctuation and increases as a Gilbert attenuation constant increases.
    Type: Grant
    Filed: August 10, 2016
    Date of Patent: August 22, 2017
    Assignees: RIKEN, University of Cologne
    Inventors: Naoto Nagaosa, Achim Rosch, Christoph Schuette
  • Patent number: 9704550
    Abstract: To provide a magnetic element that controls generation and annihilation of a skyrmion. A magnetic element is provided, and the magnetic element comprises: a magnetic body that has a spiral magnetic structure in a stable state; a skyrmion control unit that generates skyrmion in the magnetic body by supplying energy to the magnetic body that has the spiral magnetic structure. Also, the magnetic element in which the skyrmion control unit brings the magnetic body into an unstable state by supplying thermal energy pulses to the magnetic body is provided. Furthermore, a skyrmion memory comprising the magnetic element is provided.
    Type: Grant
    Filed: May 31, 2016
    Date of Patent: July 11, 2017
    Assignee: RIKEN
    Inventors: Hiroshi Oike, Fumitaka Kagawa, Yoshinori Tokura
  • Patent number: 9653136
    Abstract: A storage device, comprising at least one spintronic element suitable for representing a state among at least n states associated with the spintronic element, n>1, characterized in that each of the n states is associated with at least one characteristic of a group of magnetic skyrmions in the spintronic element, and in that said characteristic associated with a state n oi is different from said characteristic associated with a state n oj when the states n oi and n oj are two different states among the n states.
    Type: Grant
    Filed: August 1, 2014
    Date of Patent: May 16, 2017
    Assignees: THALES, CENTRE NATIONAL DE LA RECHERCHE SCIENTIFIQUE (C.N.R.S.), UNIVERSITÉ PARIS-SUD
    Inventors: Vincent Cros, Albert Fert, Joao Sampaio, Pierre Seneor
  • Patent number: 9641143
    Abstract: An electronic device includes a transimpedance amplifier stage having an amplifier end stage of the class AB type and a preamplifier stage coupled between an output of a frequency transposition stage and an input of the amplifier end stage. A self-biased common-mode control stage is configured to bias the preamplifier stage. The preamplifier stage is formed by a differential amplifier with an active load that is biased in response to the self-biased common-mode control stage.
    Type: Grant
    Filed: June 24, 2016
    Date of Patent: May 2, 2017
    Assignee: STMicroelectronics SA
    Inventor: Laurent Chabert
  • Patent number: 9542990
    Abstract: A semiconductor memory device and a method for accessing the same are disclosed. The semiconductor memory device includes an oxide heterojunction transistor which includes: an oxide substrate; an oxide film on the oxide substrate, wherein an interfacial layer between the oxide substrate and the oxide film behaves like two-dimensional electron gas; a source electrode and a drain electrode being located on the oxide film and electrically connected with the interfacial layer; a front gate on the oxide film; and a back gate on a lower surface of the oxide substrate, wherein the source electrode and the drain electrode of the oxide heterojunction transistor are respectively connected with a first word line and a first bit line for reading operation, and wherein the front gate and the back gate are respectively connected with a second word line and a second bit line for writing operation.
    Type: Grant
    Filed: February 28, 2012
    Date of Patent: January 10, 2017
    Assignee: Institute of Microelectronics, Chinese Academy of Sciences
    Inventors: Zhengyong Zhu, Zhijiong Luo
  • Patent number: 9234738
    Abstract: A detection track includes a first detection element group that includes a plurality of first magnetic resistance elements arranged at a pitch ?/(2n) when an order to cancel target harmonic components among a plurality of harmonic components superimposed on a fundamental component of a detection signal for multi-pole magnetic pattern is assumed as n, and a second detection element group that includes a plurality of second magnetic resistance elements arranged at the pitch ?/(2n), a plurality of first dummy magnetic resistance elements arranged among the first magnetic resistance elements, and a plurality of second dummy magnetic resistance elements arranged among the second magnetic resistance elements.
    Type: Grant
    Filed: November 18, 2010
    Date of Patent: January 12, 2016
    Assignee: Mitsubishi Electric Corporation
    Inventors: Takumi Asano, Takeshi Musha, Hiroshi Nishizawa, Takashi Okamuro, Noriyasu Hasegawa
  • Publication number: 20150146469
    Abstract: A method of storing one or more bits of information comprising: forming a magnetic bubble; and storing a said bit of information encoded in a typology of a domain wall of said magnetic bubble. Preferably a bit is encoded using a symmetric topological state of the domain wall and a topological state including at least one winding rotation of a magnetisation vector of the domain wall. Preferably the magnetic bubble is confined in an island of magnetic material, preferably of maximum dimension less than 1 ?m.
    Type: Application
    Filed: October 24, 2014
    Publication date: May 28, 2015
    Inventor: Christoforos Moutafis
  • Patent number: 8963545
    Abstract: The present invention relates to a magnetic sensor that provides the sensitivity adjustment on a wafer and that has a superior mass productiveness and a small characteristic variation. The magnetic sensor includes a magnetic sensitive portion provided on a substrate that is made of a compound semiconductor and that has a cross-shaped pattern. This magnetic sensitive portion includes input terminals and output terminals. At least one of input terminals of the input terminal is series-connected to a trimming portion having a compound semiconductor via a connection electrode. By performing laser trimming on the trimming portion series-connected via the connection electrode to the magnetic sensitive portion while performing a wafer probing (electric test), the adjustment of the constant voltage sensitivity is provided.
    Type: Grant
    Filed: June 29, 2010
    Date of Patent: February 24, 2015
    Assignee: Asahi Kasei Microdevices Corporation
    Inventor: Satomi Watanabe
  • Patent number: 8901530
    Abstract: Embodiments of the invention generally include a method of forming a nonvolatile memory device that contains a resistive switching memory element that has improved device switching performance and lifetime, due to the addition of a current limiting component disposed therein. The electrical properties of the current limiting component are configured to lower the current flow through the variable resistance layer during the logic state programming steps by adding a fixed series resistance in the resistive switching memory element of the nonvolatile memory device. In one embodiment, the current limiting component comprises a tunnel oxide that is a current limiting material disposed within a resistive switching memory element in a nonvolatile resistive switching memory device.
    Type: Grant
    Filed: February 19, 2014
    Date of Patent: December 2, 2014
    Assignees: SanDisk 3D LLC, Kabushiki Kaisha Toshiba
    Inventors: Mihir Tendulkar, Imran Hashim, Yun Wang
  • Patent number: 8829901
    Abstract: A method to measure a magnetic field is provided. The method includes applying an alternating drive current to a drive strap overlaying a magnetoresistive sensor to shift an operating point of the magnetoresistive sensor to a low noise region. An alternating magnetic drive field is generated in the magnetoresistive sensor by the alternating drive current. When the magnetic field to be measured is superimposed on the alternating magnetic drive field in the magnetoresistive sensor, the method further comprises extracting a second harmonic component of an output of the magnetoresistive sensor. The magnetic field to be measured is proportional to a signed amplitude of the extracted second harmonic component.
    Type: Grant
    Filed: November 4, 2011
    Date of Patent: September 9, 2014
    Assignee: Honeywell International Inc.
    Inventor: Bharat B. Pant
  • Publication number: 20140177309
    Abstract: A method of storing one or more bits of information comprising: forming a magnetic bubble; and storing a said bit of information encoded in a typology of a domain wall of said magnetic bubble. Preferably a bit is encoded using a symmetric topological state of the domain wall and a topological state including at least one winding rotation of a magnetisation vector of the domain wall. Preferably the magnetic bubble is confined in an island of magnetic material, preferably of maximum dimension less than 1 ?m.
    Type: Application
    Filed: February 26, 2014
    Publication date: June 26, 2014
    Applicant: ECOLE POLYTECHNIQUE FEDERALE DE LAUSANNE (EPFL)
    Inventors: Christoforos MOUTAFIS, Stavros KOMINEAS
  • Publication number: 20130294131
    Abstract: A method of storing one or more bits of information comprising: forming a magnetic bubble; and storing a said bit of information encoded in a typology of a domain wall of said magnetic bubble. Preferably a bit is encoded using a symmetric topological state of the domain wall and a topological state including at least one winding rotation of a magnetisation vector of the domain wall. Preferably the magnetic bubble is confined in an island of magnetic material, preferably of maximum dimension less than 1 ?m.
    Type: Application
    Filed: March 18, 2013
    Publication date: November 7, 2013
    Inventors: Christoforos MOUTAFIS, Stavros KOMINEAS
  • Patent number: 8546898
    Abstract: An optoelectronic memory cell has a transparent top electrode, a photoactive layer, a latching layer, and a bottom electrode. The photoactive layer absorbs photons transmitted through the top electrode and generates charge carriers. During light exposure, the latching layer changes its resistance under an applied electric field in response to the generation of charge carriers in the photoactive layer.
    Type: Grant
    Filed: September 29, 2009
    Date of Patent: October 1, 2013
    Assignee: Hewlett-Packard Development Company, L.P.
    Inventors: Lars Thylen, Alexandre Bratkovski, Shih-Yuan Wang, R. Stanley Williams
  • Patent number: 8492859
    Abstract: A magnetic tunnel junction (MTJ) includes first and second magnetic layers; a tunnel barrier located between the first and second magnetic layers; a first spacer layer located between the first magnetic layer and the tunnel barrier, the first spacer layer comprising a non-magnetic material; and a first interfacial layer located between the first spacer layer and the tunnel barrier.
    Type: Grant
    Filed: February 15, 2011
    Date of Patent: July 23, 2013
    Assignee: International Business Machines Corporation
    Inventor: Guohan Hu
  • Publication number: 20110261602
    Abstract: A method of storing one or more bits of information comprising: forming a magnetic bubble; and storing a said bit of information encoded in a typology of a domain wall of said magnetic bubble. Preferably a bit is encoded using a symmetric topological state of the domain wall and a topological state including at least one winding rotation of a magnetisation vector of the domain wall. Preferably the magnetic bubble is confined in an island of magnetic material, preferably of maximum dimension less than 1 ?m.
    Type: Application
    Filed: May 26, 2009
    Publication date: October 27, 2011
    Applicant: ECOLE POLYTECHNIQUE FEDERALE DE LAUSANNE (EPFL)
    Inventors: Christoforos Moutafis, Stravros Komineas
  • Patent number: 8044816
    Abstract: An apparatus, system, and method are disclosed for detecting the formation of a short between a magnetoresistive (“MR”) head and a head substrate. The apparatus is presented with a logic unit containing a plurality of modules configured to functionally execute the necessary steps of generating a baseline electric potential level between a head substrate and ground, monitoring the level of the electric potential between the head substrate and ground, and detecting the formation of a short circuit between the MR head and the head substrate by detecting a change in the electric potential level monitored by the monitoring module from the baseline level to a predetermined threshold level. Beneficially, such an apparatus, system, and method would reduce read errors on the magnetic tape storage system, the time and resources required to recover from such errors, and allow for preventative measures to obviate contamination short related failures of tape drive systems.
    Type: Grant
    Filed: February 1, 2007
    Date of Patent: October 25, 2011
    Assignee: International Business Machines Corporation
    Inventors: Brian Axtman, Robert Glenn Biskeborn, Stanley W. Czarnecki, Larry LeeRoy Tretter
  • Patent number: 7736234
    Abstract: Gaming machines and systems having MRAM and MROM are disclosed. MROMs for storing boot programs and other Read Only code are formed by cutting write connections or not providing PCB socket leads to MRAM write pins, or by using memory hubs to prevent writing to MRAMs. A tale-tale board or other logging device monitoring activities at various components while primary machine power is down records to MRAM, which can be dual ported to the logging device and MGC. Various components can each have dedicated logging devices and MRAMs. One MRAM associated with the brain box replaces both DRAM and NVRAM of regular machine architectures, and is used for dual purposes of regular operational use and as safe storage to facilitate a state recovery. Prioritization of data during the storage process is rendered unnecessary. Another MRAM associated with the back plane board stores data associated with the exterior housing or terminal.
    Type: Grant
    Filed: March 9, 2005
    Date of Patent: June 15, 2010
    Assignee: IGT
    Inventors: Warner R. Cockerille, Jamal Benbrahim, William R. Brosnan, Xuedong Chen, Gregory A. Schlottmann, Bryan D. Wolf
  • Patent number: 7722468
    Abstract: Gaming machines and systems having MRAM and MROM are disclosed. MROMs for storing boot programs and other Read Only code are formed by cutting write connections or not providing PCB socket leads to MRAM write pins, or by using memory hubs to prevent writing to MRAMs. A tale-tale board or other logging device monitoring activities at various components while primary machine power is down records to MRAM, which can be dual ported to the logging device and MGC. Various components can each have dedicated logging devices and MRAMs. One MRAM associated with the brain box replaces both DRAM and NVRAM of regular machine architectures, and is used for dual purposes of regular operational use and as safe storage to facilitate a state recovery. Prioritization of data during the storage process is rendered unnecessary. Another MRAM associated with the back plane board stores data associated with the exterior housing or terminal.
    Type: Grant
    Filed: March 9, 2005
    Date of Patent: May 25, 2010
    Assignee: IGT
    Inventors: Warner R. Cockerille, Xuedong Chen, Nadeem A. Quraishi, Gregory A. Schlottmann
  • Patent number: 6917088
    Abstract: A magneto-resistive device has a high reproducing output and is suitable for use as a CPP-GMR device. The magneto-resistive device has a first magnetic layer, a second magnetic layer, and a non-magnetic spacer formed between the first and second magnetic layers. The first magnetic layer contains a magnetic material whose conduction electrons belong to a first energy band, and the second magnetic layer contains a magnetic material whose conduction electrons belong to a second energy band. The first and second energy bands are attributable to orbitals of the same kind, thereby increasing the ratio of change in magnetoresistance and adjusting the electric resistance.
    Type: Grant
    Filed: December 31, 2002
    Date of Patent: July 12, 2005
    Assignee: Hitachi, Ltd.
    Inventors: Hiromasa Takahashi, Jun Hayakawa, Susumu Soeya, Kenchi Ito
  • Patent number: 6795336
    Abstract: The present invention discloses a magnetic random access memory for reading two or more data, by sensing the current flowing into source and drain regions. The current is regulated by the amount of a current flowing through an MRJ in an MRAM cell according to a word line voltage. In order to accomplish this object of the present invention, the MRAM comprises a data detecting circuit for converting a current flowing through an MTJ in the MRAM cell into a voltage and detecting data resulting in magnetization orientation ge.
    Type: Grant
    Filed: October 23, 2002
    Date of Patent: September 21, 2004
    Assignee: Hynix Semiconductor Inc.
    Inventors: Jung Hwan Kim, Hee Bok Kang, Geun Il Lee
  • Patent number: 6639829
    Abstract: A configuration and method for low-loss writing of an MRAM includes setting voltages at bit lines and word lines such that the voltage across the memory cells between a selected word/bit line and the individual bit line/word lines is minimal. A voltage drop occurs on a selected word/bit line connected to a particular memory cell when writing into the memory cell and voltages at the bit/word lines are set to minimize a cell voltage across the memory cells between a selected word/bit line and individual bit/word lines. A voltage drop occurs on a selected word/bit line connected to a particular memory cell when writing into the particular cell, and, when a voltage V1 and a voltage V2<V1 are present at a respective end of the selected word line/bit lines, the cell field is configured to have all of the bit/word lines set to voltages (V1+V2)/2 and to have a maximum cell voltage of ±(V1−V2)/2.
    Type: Grant
    Filed: August 3, 2001
    Date of Patent: October 28, 2003
    Assignee: Infineon Technologies AG
    Inventors: Dietmar Gogl, Helmut Kandolf, Stefan Lammers
  • Patent number: 6624457
    Abstract: The present invention relates to a ferroelectric polymer storage device including at least two stacked ferroelectric polymer memory structures that are arrayed next to at least two respective stacked topologies that are a pre-fabricated silicon substrate cavity that includes interlayer dielectric layers and via structures.
    Type: Grant
    Filed: July 20, 2001
    Date of Patent: September 23, 2003
    Assignee: Intel Corporation
    Inventors: Jian Li, Xiao-Chun Mu
  • Patent number: 6281538
    Abstract: An improved and novel multi-layer thin film device including a graded-stoichiometry insulating layer (16) and a method of fabricating a multi-layer thin film device including a graded-stoichiometry insulating layer (16). The device structure includes a substrate (12), a first electrode (14), a second electrode (18), and a graded-stoichiometry insulating, or tunnel-barrier, layer (16) formed between the first electrode (14) and the second electrode (18). The graded-stoichiometry insulating tunnel-barrier layer (16) includes graded stoichiometry to compensate for thickness profile and thereby produce a uniform tunnel-barrier resistance across the structure (10).
    Type: Grant
    Filed: March 22, 2000
    Date of Patent: August 28, 2001
    Assignee: Motorola, Inc.
    Inventor: Jon Slaughter
  • Patent number: 6211559
    Abstract: A symmetric magnetic tunnel device including first and second magnetic tunnel junctions each including a pinned magnetic layer, an insulating tunnel layer and a free magnetic layer stacked in parallel juxtaposition to allow tunneling of electrons through the insulating tunnel layer between the pinned and free magnetic layers. The first and second magnetic tunnel junctions positioned in parallel juxtaposition so as to form a continuous electron path through the first and second magnetic tunnel junctions and to provide a cell signal across the first and second magnetic tunnel junctions greater than a cell signal across each of the first and second magnetic tunnel junctions individually.
    Type: Grant
    Filed: February 27, 1998
    Date of Patent: April 3, 2001
    Assignee: Motorola, Inc.
    Inventors: Theodore Zhu, Herbert Goronkin
  • Patent number: 6204071
    Abstract: A method for forming a longitudinally magnetically biased dual stripe magnetoresistive (DSMR) sensor element comprises forming a first patterned magnetoresistive (MR) layer. Contact the opposite ends of the patterned magnetoresistive (MR) layer with a first pair of stacks defining a track width of the first magnetoresistive (MR) layer, each of the stacks including a first Anti-Ferro-Magnetic (AFM) layer and a first lead layer. Then anneal the device in the presence of a longitudinal external magnetic field. Next, form a second patterned magnetoresistive (MR) layer above the previous structure. Contact the opposite ends of the second patterned magnetoresistive (MR) layer with a second pair of stacks defining a second track width of the second patterned magnetoresistive (MR) layer. Each of the second pair of stacks includes spacer layer composed of a metal, a Ferro-Magnetic (FM) layer, a second Anti-Ferro-Magnetic (AFM) layer and a second lead layer.
    Type: Grant
    Filed: September 30, 1999
    Date of Patent: March 20, 2001
    Assignee: Headway Technologies, Inc.
    Inventors: Kochan Ju, Mao-Min Chen, Cheng T. Horng, Jei-Wei Chang
  • Patent number: 6166948
    Abstract: An improved magnetic tunnel junction (MTJ) memory cell for use in a nonvolatile magnetic random access memory (MRAM) array has a free layer formed as two ferromagnetic films that are magnetostatically coupled antiparallel to one another by their respective dipole fields. The magnetostatic or dipolar coupling of the two ferromagnetic films occurs across a nonferromagnetic spacer layer that is selected to prevent exchange coupling between the two ferromagnetic films. The magnetic moments of the two ferromagnetic films are antiparallel to another so that the multilayer free layer structure has a reduced net magnetic moment.
    Type: Grant
    Filed: September 3, 1999
    Date of Patent: December 26, 2000
    Assignee: International Business Machines Corporation
    Inventors: Stuart Stephen Papworth Parkin, Luc Thomas
  • Patent number: 5982658
    Abstract: A magnetoresistive memory array which has a row of active sense lines with each sense line including magnetoresistive bits and word lines extending over the bits. Each active sense line ending in a termination bit having a configuration selected to cause an adjacent bit to experience a magnetic field similar to that experienced by the remaining bits in the sense line. An inactive sense line located at each end of the row of active sense lines.
    Type: Grant
    Filed: October 31, 1997
    Date of Patent: November 9, 1999
    Assignee: Honeywell Inc.
    Inventors: Lonny L. Berg, Paul W. Cravens, Allan T. Hurst, Tangshiun Yeh
  • Patent number: 5088059
    Abstract: Detection device for a magnetic bubble memory having a detection zone (6) constituted by rows (7) of patterns (8) suitable for the propagation of bubbles in strip form, as well as a transition zone (10) making it possible to draw out the bubbles in strip form. The transition zone 10 has at least one row (18) of soft magnetic material patterns, (18) which has at least one central pattern (22) and a second pattern (24) adjacent to the central pattern (22). The central pattern (22) has a first part (22a) able to guide a magnetic bubble and a second part (22b) able to aid the propagation of a bubble in strip form. The second pattern (24) is able to aid the propagation of a bubble in strip form, while not disturbing the propagation of a bubble along the first part (22a) of the central pattern (22).
    Type: Grant
    Filed: March 21, 1990
    Date of Patent: February 11, 1992
    Assignee: Commissariat a l'Energie Atomique
    Inventors: Jean-Marc Fedeli, Joel Magnin
  • Patent number: 4912673
    Abstract: Magnetic bubble memory in hybrid technology using rows of chevron patterns. The memory detection system has an active detection zone (4) constituted by rows of chevrons, in order to stretch into the form of a strip the bubbles from a propagation path (2), and a first detector (8); a bubble elimination zone (12) constituted by forcing back means (18) for stopping the advance of the bubbles and for forcing them outside the detection system; and a passive detection zone (6) located following the bubble elimination zone (12) and incorporating a second detector (9), to which no bubble must be exposed, in order to eliminate the unwanted signal due to the influence of a rotary magnetic field necessary for the propagation of the bubbles. According to the invention, elimination zone (12) is provided with at least one barrier (20) produced by ion implantation in order to block the passage of the bubbles from active zone (4) to passive zone (6).
    Type: Grant
    Filed: December 30, 1988
    Date of Patent: March 27, 1990
    Assignee: Commissariat a l'Energie Atomique
    Inventors: Jean-Marc Fedeli, Joel Magnin, Marie-Therese Delaye, Marc Rabarot
  • Patent number: 4829476
    Abstract: A sensing circuit for sensing magnetic states of magnetic bit structures through selectively providing current through and across selected ones of such bit structures while selectively sensing and comparing voltage drops thereacross.
    Type: Grant
    Filed: July 28, 1987
    Date of Patent: May 9, 1989
    Assignee: Honeywell Inc.
    Inventors: Timmothy J. Dupuis, James D. Reinke, William J. Linder
  • Patent number: 4811286
    Abstract: A magnetic bubble memory has a reading zone with thin detection elements, coated with an insulating layer which carries thick bubble propagation patterns of high magnetic permeability material, and a bubble stretching zone also including thick propagation patterns of shapes such that the rotating field of the device causes the bubbles to progress along the patterns. The device further includes, out of the detection zone, additional thin localized elements of high magnetic permeability material having a thickness much lower than that of the patterns, obtainable by photolithography and located at the same level as the thin detection elements. When located in the stretching zone, the thin patterns are arranged to cooperate with thick patterns so that the voltage well generated by the rotating field of the device has a substantially constant value while moving along the thick patterns.
    Type: Grant
    Filed: February 2, 1987
    Date of Patent: March 7, 1989
    Assignee: Societe d'Applications Generales
    Inventor: Michel Poirier
  • Patent number: 4686472
    Abstract: A magnetic sensor for sensing magnetic fields including two flat layers of electrically conductive ferromagnetic material (11, 16) each having an in-plane easy axis of magnetization (EA.sub.1, EA.sub.2) and each producing a resistance variation under the influence of a magnetic field Ha which originates from a source at an edge of the layer, which layers are situated a small distance apart parallel with respect to each other. In order to increase the sensor's sensitivity to small magnetic fields, in operation the layers (11, 16) convey currents flowing in the same direction and are connected in parallel to the input terminals of a detection circuit (2, 9).
    Type: Grant
    Filed: February 10, 1986
    Date of Patent: August 11, 1987
    Assignee: U.S. Philips Corporation
    Inventors: Johannes A. C. Van Ooijen, Jacobus J. M. Ruigrok
  • Patent number: 4589095
    Abstract: A magnetic bubble stretcher comprises a bubble fanning part for propagating a magnetic bubble while gradually stretching the bubble and a bubble propagation part for propagating the stretcher bubble. The bubble fanning and propagation parts include a bubble propagation patterns as fundament elements for stretching or propagating the bubble the bubble propagation patterns in the bubble fanning part are different in shape and/or dimension from the bubble propagation patterns in the bubble propagation part.
    Type: Grant
    Filed: August 1, 1984
    Date of Patent: May 13, 1986
    Assignee: Hitachi, Ltd.
    Inventors: Ryo Suzuki, Teruaki Takeuchi, Masatoshi Takeshita, Naoki Kodama, Yutaka Sugita
  • Patent number: 4589041
    Abstract: An MR sensor is disclosed in which a pair of thin film magnetoresistive strips are connected electrically in parallel between two terminals. Strips are spaced apart a distance which is small relative to the density of the stored data to be sensed. The strips are mutually-biased in opposite directions to corresponding points in the linear region of their respective curves by current from a constant source attached to one terminal. Since the resistance of each strip is equal, the current divides equally between the strips.The sensor is positioned adjacent the magnetic surface containing stored data. Vertical components of the magnetic field (preferably vertically recorded data) influence the resistance of the strips differentially. When the sensor encounters a vertical flux transition, the output voltage varies to produce a unimodal type pulse.
    Type: Grant
    Filed: August 30, 1982
    Date of Patent: May 13, 1986
    Assignee: International Business Machines Corporation
    Inventor: Otto Voegeli
  • Patent number: 4538242
    Abstract: A signal processing circuit for a magnetic bubble memory device is arranged to set a reference level for determining the level of "1" or "0" of the bubble sensing line signal during a period in which only a read signal corresponding to level "0" appears as the output signal of a differential amplifier of the bubble detector circuit.
    Type: Grant
    Filed: July 6, 1983
    Date of Patent: August 27, 1985
    Inventors: Takashi Toyooka, Aoki Hirokazu, Mamoru Sugie, Yutaka Sugita
  • Patent number: 4525807
    Abstract: A magnetic bubble store, using adjoining non-implanted motifs as bubble-propagating motifs, the store comprising 3n identical, electrically interconnected storage devices, n being a positive integer, which are produced on an identical circuit chip and each comprise minor loops for storing the bubbles, at least one major loop acting as an access loop for the minor loops, first electrical component enabling bubbles to be transferred from the minor loops to the major loop and vice versa, a second electrical component enabling bubbles to be produced on the major loop, and a third electrical component enabling the bubbles on the major loop to be detected, the third, identical component, each formed by an electric conductor for bubble extension and contraction and a magneto-resistive element, being disposed in directions making an angle of 120.degree. with one another.
    Type: Grant
    Filed: January 17, 1984
    Date of Patent: June 25, 1985
    Assignee: Commissariat a l'Energie Atomique
    Inventors: Hubert Jouve, Joel Magnin
  • Patent number: 4517662
    Abstract: A magnetic bubble memory (of the type that has a magnetic film, a plurality of magnetic bubbles in the film, and an insulating layer over the film) includes an improved electromagnetic structure on the insulating layer for stretching the bubbles to aid in their detection; which structure is comprised of a plurality of elongated permalloy elements on the insulator and arranged in spaced apart rows with only one of the elements per row; each element has a pattern that is X-shaped which repeats along the element in the direction of elongation; the X in the pattern has two short legs and two long legs; and the pattern is repeated such that the short legs of one X join with the long legs of the next X.
    Type: Grant
    Filed: June 29, 1983
    Date of Patent: May 14, 1985
    Assignee: Burroughs Corporation
    Inventor: LuVerne R. Peterson
  • Patent number: 4514828
    Abstract: A temperature compensated, phase tolerant sense amplifier for use in a magnetic bubble memory system in which current is applied to the detector resistors only during a bubble detect operation.
    Type: Grant
    Filed: January 18, 1982
    Date of Patent: April 30, 1985
    Assignee: Texas Instruments Incorporated
    Inventors: Thomas A. Closson, David B. Oxford, Stephen R. Schenck, Jerold A. Seitchik
  • Patent number: 4511995
    Abstract: A magnetic bubble memory includes a planar magnetic film containing a plurality of magnetic bubbles which move in response to a magnetic field that rotates the film's plane; and further includes an improved mechanism for detecting the bubbles comprised of: a pair of elongated magnetoresistive members that lie over the film alongside of one another; the members having fingers that extend towards each other along the direction of elongation; the fingers of one member being interdigitated with the fingers of the other member such that they mesh together but do not touch; the fingers being interdigitated at angles of less than 180.degree. so that magnetic poles which attract the bubbles are sequentially induced in the fingers of only one member, in the fingers of both members, and in the fingers of only the other member by each rotation of the field.
    Type: Grant
    Filed: June 29, 1983
    Date of Patent: April 16, 1985
    Assignee: Burroughs Corporation
    Inventor: LuVerne R. Peterson
  • Patent number: 4502129
    Abstract: A magnetic bubble detector has a stretcher part for stretching a magnetic bubble while propagating it and a detection part for detecting the magnetic bubble while propagating it. In the magnetic bubble detector, the period of arrangement of bubble propagation elements forming the exit of the stretcher part viewed in a bubble propagation direction is larger than the period of arrangement of bubble propagation elements forming the entrance of the stretcher part viewed in a bubble propagation direction.
    Type: Grant
    Filed: June 17, 1983
    Date of Patent: February 26, 1985
    Assignee: Hitachi, Ltd.
    Inventors: Ryo Suzuki, Minoru Hiroshima, Masatoshi Takeshita, Yutaka Sugita
  • Patent number: 4485319
    Abstract: A sense amplifier which is fully integrated has an on-chip voltage regulator to provide essentially error free operation. The sense amplifier provides peak-to-peak signal detection for comparison to a threshold voltage by a comparator. The output of the comparator is coupled to an RS flip-flop. The output of the RS flip-flop is coupled to a D flip-flop. The use of an RS flip-flop as well as a D flip-flop eliminates clocking problems caused by skewing and keeps a stored detected signal from changing prematurely.
    Type: Grant
    Filed: February 26, 1982
    Date of Patent: November 27, 1984
    Assignee: Motorola, Inc.
    Inventors: Robert B. Davies, Robert N. Dotson, Ira Miller
  • Patent number: 4475238
    Abstract: An image correlation device utilizing the principle of magnetoresistance. A sensed image is compared to a preselected mask image to determine whether the two images match. The comparison is accomplished by electrically representing the sensed image along a first surface and the mask image along a second surface of magnetoresistive member or body of material (a magnetoresistive member is one which demonstrates a greater amount of electrical resistance transverse to a magnetic field to which the member is exposed than it does parallel to that field). Where the two images match such that there is a maximum number of corresponding points along these surfaces a maximum amount of current flows through the body. Moreover, matching images can be compared and a match recognized even where the images are at different positions along their respective top and bottom surfaces of the magnetoresistive block.
    Type: Grant
    Filed: April 5, 1982
    Date of Patent: October 2, 1984
    Inventor: Glenn C. Everhart
  • Patent number: 4470873
    Abstract: A magnetic sensor including first and second electromagnetic elements arranged one on the other is manufactured by depositing on a glass substrate a first magnetoresistive film of Fe-Ni permalloy, an insulating film of SiO.sub.2 and a second magnetoresistive film of Fe-Ni permalloy successively in this order and then these three films are simultaneously etched by a single etching treatment with aid of a photomask to form first and second magnetoresistive elements. Then, through-holes are formed in the second magnetoresistive film and insulating film to expose parts of the first magnetoresistive film. Next, an insulating photoresist film of polyimide is applied on the second magnetoresistive film and openings are formed in the insulating photoresist film at positions of the bottom of the through-holes and at positions corresponding to junctions to the second magnetoresistive film.
    Type: Grant
    Filed: November 30, 1983
    Date of Patent: September 11, 1984
    Assignee: Copal Company Limited
    Inventor: Shigekazu Nakamura
  • Patent number: 4471467
    Abstract: A magnetic device comprising at least one thin layer of a magnetizable material which has an easy axis of magnetization approximately normal to the surface of the layer. Magnetic domains are propagated in the layer by a rotating magnetic field in co-operation with a pattern of magnetizable material on the layer. Domains are detected by passing a current through a pattern of magneto-resistive material on the layer. At least in the part of the device where the detection occurs, the propagation and detection patterns have substantially the same configuration and one pattern is situated between the layer of magnetizable material and the other pattern.
    Type: Grant
    Filed: March 6, 1979
    Date of Patent: September 11, 1984
    Assignee: U.S. Philips Corporation
    Inventors: Frederik A. de Jonge, Antonius G. H. Verhulst
  • Patent number: 4460976
    Abstract: A field-access magnetic bubble memory includes an improved expander-detector arrangement. An optimized element shape provides for a constant magnetic field strength at critical points in the drive field cycle. Improved high bias operation results.
    Type: Grant
    Filed: November 9, 1981
    Date of Patent: July 17, 1984
    Assignee: AT&T Bell Laboratories
    Inventor: Andrew H. Bobeck
  • Patent number: 4458335
    Abstract: A detector structure for contiguous-disk bubble devices has a non-ionimplanted elongated bar, a hairpin conductor and a thin-film magneto-resistive element. The elongated bar is positioned in spaced relation to a large period element at the end of a propagation loop. The elongated bar extends both above and below the large period element and prevents the bubble from passing around the element. The hairpin conductor is positioned over the edge of the bar that faces the end period element. The magneto-resistive element is positioned parallel to and at the center of the hairpin conductor.
    Type: Grant
    Filed: April 1, 1983
    Date of Patent: July 3, 1984
    Assignee: International Business Machines Corporation
    Inventors: William J. Kabelac, Ian L. Sanders
  • Patent number: 4445200
    Abstract: A current stretch detection method for a bubble device in which bubbles are written at least one bit apart. A stretch pulse is applied to a stretch conductor so that when a bubble is detected, it is maintained stretched, even though the bubble following it has moved one bit. Preferably the stretch pulse is of a convex-shape. A bubble device has a hairpin stretch conductor and a detecting element disposed centrally in the conductor. The terminal of the detecting element on the higher potential side is arranged so that it does not cross the stretch conductor. The contiguous propagation pattern is provided with a notch at a position in which the stretch conductor is located.
    Type: Grant
    Filed: September 18, 1981
    Date of Patent: April 24, 1984
    Assignee: Fujitsu Limited
    Inventors: Makoto Ohashi, Kazunari Komenou, Tsutomu Miyashita, Kazuo Matsuda, Yoshio Satoh