Demagnetizing Patents (Class 361/149)
  • Patent number: 9268402
    Abstract: An operator control device has an operating element with haptic feedback. The operating element has a touch-sensitive operator control area and is operated through an input element. The device includes a first and a stationary second flat component that are composed of a ferromagnetic material and arranged to face each other in parallel by way of their large areas. The operator control device also includes a coil or an electrical conductor that is arranged between the first and second flat components and associated with a first pole shoe that is connected to the second flat component and projects in relation to the first flat component. A magnetic field can be generated by applying current to the coil or to the conductor, and the first flat component is driven by the magnetic field such that the first flat component can be displaced horizontally with respect to the stationary second flat component.
    Type: Grant
    Filed: August 1, 2012
    Date of Patent: February 23, 2016
    Assignee: Continental Automotive GmbH
    Inventors: Alexander Thorsten Kern, Ingo Zoller
  • Patent number: 9133534
    Abstract: A method of processing a metal for improved damping of a metal part is provided. The method comprises placing the metal part inside a current carrying coil and closing a circuit for to apply current to the coil, thus producing a magnetic field in the metal part. Thereafter, the circuit is opened for a time and then the circuit is closed a second time to apply a second current to the coil. The circuit is then opened a second time and the metal part is removed from the current carrying coil.
    Type: Grant
    Filed: June 10, 2011
    Date of Patent: September 15, 2015
    Assignees: RASSINI FRENOS, S.A. DE C.V., THE UNIVERSITY OF WINDSOR
    Inventors: Jason Paul Mitchick, Raju Karthik, Mauricio Gonzalez-Rocha, Jerzy Hieronim Sokolowski
  • Publication number: 20150093705
    Abstract: The present invention provides a demagnetizing apparatus for demagnetization of an object, comprising a coil configured to generate a magnetic field for demagnetizing the object, and a supply device configured to supply, to the coil, an alternating current whose amplitude decreases with time, wherein the supply device supplies the alternating current to the coil such that an amplitude of the alternating current is larger than an absolute value of a current value at which magnetic saturation is occurred in the object in a first period, an absolute value of a rate of change in amplitude of the alternating current is larger than that in the first period in a second period, and an amplitude of the alternating current is smaller than an absolute value of a current value corresponding to a coercive force of the object in a third period.
    Type: Application
    Filed: September 17, 2014
    Publication date: April 2, 2015
    Inventor: Shinji Uchida
  • Publication number: 20150085418
    Abstract: An integrated circuit for demagnetizing an inductive load includes a first switch to control current supplied by a voltage supply to the inductive load. A Zener diode includes an anode connected to a control terminal of the first switch and a cathode connected to the voltage supply. A second switch includes a control terminal and first and second terminals. A temperature sensing circuit is configured to sense a temperature of the first switch and to generate a sensed temperature. A comparing circuit includes inputs that receive a reference temperature and the sensed temperature and an output connected to the control terminal of the second switch.
    Type: Application
    Filed: February 20, 2014
    Publication date: March 26, 2015
    Applicant: Maxim Integrated Products, Inc.
    Inventors: Siro Buzzetti, Marco Demicheli, Danilo Ranieri
  • Publication number: 20150016006
    Abstract: Automated degaussing methods and apparatus are presented for degaussing a magnetic core in close loop fashion, in which a plurality of pulses are applied to a compensation coil magnetically coupled with the core with duration or energy being decreased in succeeding pulse cycles according to a discrete feedback algorithm, and with individual pulse polarities being set according to core magnetization polarity measured subsequent to an immediately preceding pulse.
    Type: Application
    Filed: February 10, 2014
    Publication date: January 15, 2015
    Applicant: Texas Instruments Deutschland GmbH
    Inventors: Caspar Petrus Laurentius van Vroonhoven, Sudarshan Udayashankar, Gebhard Haug, Mikhail Valeryevich Ivanov
  • Patent number: 8934210
    Abstract: A method for demagnetizing comprising positioning a core within the electromagnetic field generated by a first winding until the generated first electrical current is not substantially increasing, thereby determining a saturation current. A second voltage, having the opposite polarity, is then applied across the first winding until the generated second electrical current is approximately equal to the magnitude of the determined saturation current. The maximum magnetic flux within the core is then determined using the voltage across said first winding and the second current. A third voltage, having the opposite polarity, is then applied across the first winding until the core has a magnetic flux equal to approximately half of the determined maximum magnetic flux within the core.
    Type: Grant
    Filed: June 28, 2012
    Date of Patent: January 13, 2015
    Assignee: U.S. Department of Energy
    Inventors: Ronald J. Denis, Nathanael J. Makowski
  • Publication number: 20140268472
    Abstract: A deactivator device for a mobile Point of Sale (mPOS) systems includes a pair of spaced apart, fixed position electromagnets positioned and configured such that magnetic fields generated by the electromagnets aid one another to form a combined magnetic field; a battery; a capacitor; and an electronics assembly including a microcontroller configured to control storage of energy from the battery in the capacitor and to selectively provide a deactivation or activation pulse from the capacitor to the electromagnets. The components may be positioned in a housing configured for attachment to a mPOS mobile device.
    Type: Application
    Filed: March 14, 2014
    Publication date: September 18, 2014
    Applicant: Tyco Fire & Security GmbH
    Inventors: RONALD B. EASTER, Douglas A. Drew
  • Patent number: 8520333
    Abstract: A structure for erasure of magnetic media in a hard drive includes a main field pole magnet polarized in a direction toward a drive spindle motor in the hard drive. At least two quadrature magnets are disposed adjacent the main field pole magnet and polarized in a direction toward the main field pole magnet. The main field pole magnet and the at least two quadrature magnets are shaped to provide a slot for insertion of the magnetic media. At least two inverse polarity magnets are disposed on portions of the main pole and quadrature magnets forming the slot. The inverse polarity magnets are polarized in a direction opposed to the direction of the main field pole magnet.
    Type: Grant
    Filed: April 11, 2011
    Date of Patent: August 27, 2013
    Assignee: Dexter Magnetic Technologies, Inc.
    Inventor: Chun Li
  • Publication number: 20130148250
    Abstract: A method and system of using a common set of coils to provide at least two of magnetic flux, heat and degaussing in a mobile platform are provided. In accordance with one embodiment, the method involves oscillation of current in the coils at a frequency higher than a defined pointing requirement to provide heat. In accordance with another aspect, the coil functions as a degausser by energizing the coil with an oscillating current that decreases in amplitude over time.
    Type: Application
    Filed: December 13, 2011
    Publication date: June 13, 2013
    Applicant: THE BOEING COMPANY
    Inventors: Christopher Alan Day, Jeffrey Jacob Brown, Kenneth Maxwell Hays
  • Patent number: 8462456
    Abstract: The present invention relates providing a magnetic data eraser that is capable of performing magnetizing process for magnetizing magnetic recording medium such as a hard disk drive (HDD) is easily and with reduced electric power. The magnetic data eraser includes: holding drawer means for holding a magnetic recording medium which means has a mounting tray for mounting the magnetic recording medium, wherein the mounting tray is inclined a predetermined value of degrees of angle; and magnetizing means for magnetizing the magnetic recording medium, wherein the magnetizing means is covered by a magnetizing coil and has a hollow body portion, the holding drawer means being accommodated in the hollow body portion, and the magnetic recording medium being placed on the mounting tray of the holding drawer means.
    Type: Grant
    Filed: September 6, 2012
    Date of Patent: June 11, 2013
    Inventor: Tadashi Honda
  • Patent number: 8379363
    Abstract: A bulk erase tool to erase a perpendicular media recording (PMR) disk of a disk drive is disclosed. The bulk erase tool comprises a housing to receive a disk drive and at least one of a first pair of magnets mounted in the housing to be positioned above the received disk drive to provide a magnetic field to erase the top side of the disk and a second pair of magnets mounted in the housing to be positioned below the disk drive to provide a magnetic field to erase the bottom side of the disk.
    Type: Grant
    Filed: March 26, 2010
    Date of Patent: February 19, 2013
    Assignee: Western Digital Technologies, Inc.
    Inventors: Pusphanathan Kolunthavelu, Anandan Vengadasalam
  • Patent number: 8345402
    Abstract: Generation of an intense magnetic field to erase high coercivity magnetic media uses delivery of energy to a degaussing cavity. To conserve energy storage and delivery requirements and to obtain a desired magnetic strength generally uniformly within the cavity, strategic placement of supplemental turns at ends of the magnetic field generating coil wound around the cavity can promote uniformity. Construction of at least cavity ends from an adequate quantity of magnetically soft ferrous material can also promote uniformity. A combination of both approaches is possible.
    Type: Grant
    Filed: February 18, 2010
    Date of Patent: January 1, 2013
    Assignee: Data Security, Inc.
    Inventor: Robert A. Schultz
  • Patent number: 8300347
    Abstract: A magnetic data eraser includes a holding drawer means for holding a magnetic recording medium which means has a mounting tray for mounting the magnetic recording medium, wherein the mounting tray is inclined a predetermined value of degrees of angle. The magnetic data eraser further includes a magnetizing means for magnetizing the magnetic recording medium, wherein the magnetizing means is covered by a magnetizing coil and has a hollow body portion. The holding drawer means being accommodated in the hollow body portion, and the magnetic recording medium being placed on the mounting tray of the holding drawer means.
    Type: Grant
    Filed: September 10, 2010
    Date of Patent: October 30, 2012
    Inventor: Tadashi Honda
  • Patent number: 8064183
    Abstract: Disclosed is an apparatus for destroying electronic memory media by use of a bi-directional degaussing device. The degaussing device utilizes an SCR gate controller to cause bi-directional polarity from a charged capacitor into a sealed chamber containing the magnetic media. The chamber has a movable steel plate cover and floor that encloses the chamber containing magnetic media during the degaussing stage. The cover and floor cause a reflective chamber that focuses and directs the flux level to the magnetic media. The gate controller allows the use of the same capacitor bank to power a coil in two different directions to obtain effective degaussing without multiple coils or directional capacitors.
    Type: Grant
    Filed: June 1, 2009
    Date of Patent: November 22, 2011
    Inventor: William E. Olliges
  • Publication number: 20110237442
    Abstract: Systems and methods for magnetic shielding are described. A magnetic shield formed of a material having a high magnetic permeability may be degaussed using a toroidal degaussing coil. The toroidal degaussing coil may enclose at least a portion of the shield. Magnetic field gradients may be actively compensated using multiple magnetic field sensors and local compensation coils. Trapped fluxons may be removed by an application of Lorentz force wherein an electrical current is passed through a superconducting plane.
    Type: Application
    Filed: March 17, 2011
    Publication date: September 29, 2011
    Inventor: Sergey V. Uchaykin
  • Patent number: 8009403
    Abstract: An apparatus and method for preconditioning a magnetic recording disk is provided in which two substantially identical, but opposing, pancake coils are disposed generally parallel to one another with a gap therebetween into which a disk to be preconditioned is inserted. A large pulse of current is delivered to the coils to generate a magnetic field that is sufficiently strong to precondition the disk. The radial fields of each respective pancake coil add together in the gap where the disk is located, and the field presets both the data layer and the hard bias layer of the SUL. Outside of the gap region, the fields cancel one another such that there are essentially no perpendicular fields due to the symmetry of the coils, such that there is very little net residual perpendicular magnetization when the disk is removed from the gap. An electrical circuit for producing the current pulse is provided. An aluminum support structure provides thermal management and magnetic flux conductivity for the system.
    Type: Grant
    Filed: September 19, 2006
    Date of Patent: August 30, 2011
    Assignee: Seagate Technology LLC
    Inventors: Michael Mallary, David Peterson
  • Patent number: 7979224
    Abstract: A configurable semiconductor device includes at least one select pin configured to connect to one of a plurality of impedances. The impedances are external to the configurable semiconductor device and have impedance values within predetermined tolerances. A measurement circuit is connected to the at least one select pin. The measurement circuit is configured to measure electrical characteristics of the plurality of impedances, correlate the electrical characteristics to respective predetermined ranges of impedances, and generate digital output values corresponding to the correlation. A controller is configured to control a characteristic of the configurable semiconductor device based on the digital output values. Spacing between the respective predetermined ranges of impedances is based on the predetermined tolerances.
    Type: Grant
    Filed: August 25, 2010
    Date of Patent: July 12, 2011
    Assignee: Marvell International Ltd.
    Inventor: Sehat Sutardja
  • Patent number: 7876519
    Abstract: A method for erasing a disk of a hard disk drive. The method includes moving the hard disk drive adjacent to an erasure head that emanates a magnetic field. The magnetic field and moving hard disk drive cause a disk of the hard disk drive to spin under a Lorentz force created by the magnetic field and moving disk. The magnetic field is applied by the erasure head for a duration that causes erasure of the entire disk. The spindle motor is not activated during the entire process. Not activating the spindle motor eliminates any Faraday coupling from the erasure head into the motor.
    Type: Grant
    Filed: December 16, 2008
    Date of Patent: January 25, 2011
    Assignee: Samsung Electronics Co., Ltd.
    Inventors: Carl Xiaodong Che, Keung Youn Cho, Soo-Youl Hong, Shuo-Hao Chen
  • Publication number: 20100302701
    Abstract: Disclosed is an apparatus for destroying electronic memory media by use of a bi-directional degaussing device. The degaussing device utilizes an SCR gate controller to cause bi-directional polarity from a charged capacitor into a sealed chamber containing the magnetic media. The chamber has a movable steel plate cover and floor that encloses the chamber containing magnetic media during the degaussing stage. The cover and floor cause a reflective chamber that focuses and directs the flux level to the magnetic media. The gate controller allows the use of the same capacitor bank to power a coil in two different directions to obtain effective degaussing without multiple coils or directional capacitors.
    Type: Application
    Filed: June 1, 2009
    Publication date: December 2, 2010
    Inventor: William E. Olliges
  • Patent number: 7813100
    Abstract: A demagnetization circuit for reducing interference in a mobile phone includes a wave filter, a demagnetization circuit and an audio playing circuit. The wave filter is configured to filter a received audio signal from the mobile phone. The wave filter includes an input that receives the audio signal, and an output. The demagnetization circuit is structured and arranged to generate an opposite magnetic field to that of the mobile phone to reduce pulse magnetic fields generated by the mobile phone.
    Type: Grant
    Filed: January 5, 2009
    Date of Patent: October 12, 2010
    Assignee: Chi Mei Communication Systems, Inc.
    Inventors: Yi-Fang Lin, Hsi-Chieh Chen
  • Patent number: 7788053
    Abstract: A configurable semiconductor has a device characteristic that is controllable as a function of at least one external impedance. A measurement circuit measures an electrical characteristic of the at least one external impedance and determines a select value corresponding to the measured electrical characteristic. A first circuit controls the device characteristic as a function of the select value.
    Type: Grant
    Filed: March 11, 2008
    Date of Patent: August 31, 2010
    Assignee: Marvell International Ltd.
    Inventor: Sehat Sutardja
  • Patent number: 7724490
    Abstract: Embodiments in accordance with the present invention provide a degaussing device and a degaussing method capable of efficiently degaussing a magnetic disk, especially, a magnetic disk of the perpendicular magnetic recording system, without resorting to a magnetic field of a high intensity. Embodiments in accordance with the present invention provide a degaussing method of degaussing a magnetic disk not yet installed in a magnetic disk drive by applying an external magnetic field to the magnetic disk by a degaussing device. In accordance with one embodiment, the method includes disposing the magnetic disk in the degaussing device such that the direction of an external magnetic field is inclined at an angle to the axis of easy magnetization of the magnetic disk.
    Type: Grant
    Filed: April 24, 2007
    Date of Patent: May 25, 2010
    Assignee: Hitachi Global Storage Technologies Netherlands B.V.
    Inventors: Hitoshi Tamura, Hiroki Mori, Mitsuru Hamaguchi, Kunihiko Mine, Takehiko Hamaguchi
  • Patent number: 7715166
    Abstract: A permanent magnet degausser includes at least one magnetic field generator comprising magnetic elements arranged near a media conveyance path and a conveyor for transporting magnetic media through a magnetic media conveyance path. A passive belt or protector plate may be provided to assist the passage of the magnetic media through the applied magnetic field. The conveyor may be a continuous motion conveyor belt including cleats for holding the magnetic media or a reciprocal media conveyor including magnetic storage media bin. The magnetic field generator may include permanent magnets of varying intrinsic coercivities and/or remanences.
    Type: Grant
    Filed: July 14, 2006
    Date of Patent: May 11, 2010
    Assignee: Data Security, Inc.
    Inventors: Robert A. Schultz, Leroy D. Thiel
  • Patent number: 7710706
    Abstract: An apparatus for demagnetizing a shadow mask includes a shadow mask stocker, a cassette in the shadow mask stocker, wherein at least one shadow mask is disposed in the cassette, and a demagnetizing device that generates a magnetic field by an alternating current (AC), thereby removing magnetism of the at least one shadow mask.
    Type: Grant
    Filed: June 22, 2007
    Date of Patent: May 4, 2010
    Assignee: LG. Display Co., Ltd.
    Inventors: Choong-Keun Yoo, Kang-Ju Lee
  • Patent number: 7701656
    Abstract: A permanent magnet degausser includes at least one magnetic field generator comprising magnetic elements arranged near a media conveyance path and a conveyor for transporting magnetic media through a magnetic media conveyance path. A passive belt or protector plate may be provided to assist the passage of the magnetic media through the applied magnetic field. The conveyor may be a continuous motion conveyor belt including cleats for holding the magnetic media or a reciprocal media conveyor including magnetic storage media bin. The magnetic field generator may include permanent magnets of varying intrinsic coercivities and/or remanences.
    Type: Grant
    Filed: July 14, 2006
    Date of Patent: April 20, 2010
    Assignee: Data Security, Inc.
    Inventors: Robert A. Schultz, Leroy D. Thiel
  • Publication number: 20100067162
    Abstract: A demagnetization circuit for reducing interference in a mobile phone includes a wave filter, a demagnetization circuit and an audio playing circuit. The wave filter is configured to filter a received audio signal from the mobile phone. The wave filter includes an input that receives the audio signal, and an output. The demagnetization circuit is structured and arranged to generate an opposite magnetic field to that of the mobile phone to reduce pulse magnetic fields generated by the mobile phone.
    Type: Application
    Filed: January 5, 2009
    Publication date: March 18, 2010
    Applicant: CHI MEI COMMUNICATION SYSTEMS, INC.
    Inventors: YI-FANG LIN, HSI-CHIEH CHEN
  • Patent number: 7652837
    Abstract: Embodiments of the invention relate to erasing data recorded on a magnetic disk with increased certainty by using an external magnetic field. One embodiment is directed to a method for erasing data recorded on a magnetic disk, which is housed in a magnetic disk drive, by using an external erasure magnetic field generated by an external erasure magnetic field generator. The method comprises the steps of: moving a first magnetic disk drive within an external erasure magnetic field in a moving state appropriate for the type of the first magnetic disk drive, and erasing data recorded on a magnetic disk in the first magnetic disk drive; and moving a second magnetic disk drive, which differs in type from the first magnetic disk drive, within an external erasure magnetic field in a moving state that differs from the moving state of the first magnetic disk drive, and erasing data recorded on a magnetic disk in the second magnetic disk drive.
    Type: Grant
    Filed: July 13, 2006
    Date of Patent: January 26, 2010
    Assignee: Hitachi Global Storage Technologies Netherlands B.V.
    Inventors: Mitsuru Kitamura, Masahiko Katoh
  • Patent number: 7646579
    Abstract: Embodiments of the invention prevent a spindle motor from stopping rotation while data on a magnetic disk is being erased by using a permanent magnet. In one embodiment, data in the whole area of the magnetic disk is erased as a consequence of the magnetic disk rotating in the magnetic field of the permanent magnet located so as to face a part of the magnetic disk. A back yoke is located so as to face a base. The back yoke gives a magnetic force to the spindle motor in the opposite direction of the magnetic force of the erasing permanent magnet so that the fluid dynamic bearing spindle motor can retain the rotation as required without stopping rotation.
    Type: Grant
    Filed: April 28, 2005
    Date of Patent: January 12, 2010
    Assignee: Hitachi Global Storage Technologies Netherlands B.V.
    Inventors: Mitsuru Kitamura, Masahiko Katoh, Hitoshi Tamura, Hiroaki Uchiyama, Masashi Murayama, Migifumi Ikeda, Kazuo Sasaki, Shigeki Watabe
  • Publication number: 20090284890
    Abstract: A system for degaussing magnetic media includes a media transport carousel mounted to move in a first direction into the system and through a magnetic field generator and to move in a second direction through the magnetic field generator and out of the system. An automatically reversible transmission transmits via a plurality of gears rotational force from an input shaft in a first rotational direction to drive the drive element and the media transport carousel in a first direction. The automatically reversible transmission is configured to transmit via a second plurality of gears the rotational force from the input shaft in the first direction to drive the drive element to move the media transport carousel in a second direction opposite of the first direction. A media rotation assembly automatically rotates the media transport carousel after it passes a distance through the magnetic field generator.
    Type: Application
    Filed: May 16, 2008
    Publication date: November 19, 2009
    Inventor: LeRoy D. THIEL
  • Publication number: 20090256375
    Abstract: The present invention relates to a method and apparatus for destroying, on site, electronic and electric equipment and media and the information contained thereon. More specifically, the present invention relates to an apparatus and method for removing information stored on electronic and electric equipment and media by degaussing and shredding the physical hardware containing the information. Each of the degausser and the shredder are contained within a mobile vehicle such that the scrap electronic and electric equipment and media may be destroyed and stored within targeted receptacles. Moreover, the mobile vehicle of the present invention is adapted to move from one location to another such that the method of destroying the electronic and electric equipment and media may be utilized on-site at the facility of a business owner, thereby, eliminating any risk associated with compromising the confidentiality of the information.
    Type: Application
    Filed: April 14, 2008
    Publication date: October 15, 2009
    Inventor: Robert A. HASKINS
  • Patent number: 7593210
    Abstract: One or more pairs of magnet assemblages (14 and 16) are provided with magnetized segments (21-30) arranged in a Halbach-like array. The magnet assemblages (14 and 16) define a gap (18) through which magnetic data storage media (12) pass in a direction (20) across the segments (21-30). The magnetized sides (36) of the magnet assemblages (14 and 16) face each other thereby creating strong magnetic fields which degauss the magnetic data storage media (12) passing through the gap (18).
    Type: Grant
    Filed: February 1, 2008
    Date of Patent: September 22, 2009
    Assignee: Data Security, Inc.
    Inventor: Robert A. Schultz
  • Patent number: 7457095
    Abstract: A method is presented for demagnetizing ferromagnetic components in an alternating field of an externally excited electrical series resonant circuit. A supply voltage having an excitation frequency (f) is applied in parallel to a demagnetization coil having a no-load inductance of the series resonant circuit, because of which an alternating current (I) flows through the series resonant circuit (1), which generates a magnetic alternating field. In the event of suitable selection of the excitation frequency (f) in such a way that the product of the excitation frequency (f) in Hz multiplied by the no-load inductance (L0) in Henry is f*L0?0,22 Hz*H, the excitation frequency is in an operating range (5) and the series resonant circuit (1) may be used without further regulation technology to demagnetize components which are led through the inner chamber of the demagnetization coil (2) and form a fill level.
    Type: Grant
    Filed: February 20, 2008
    Date of Patent: November 25, 2008
    Inventors: Albert Maurer, Marek Rohner
  • Patent number: 7451719
    Abstract: A method and apparatus for degaussing a water vessel. The invention involves the use of a light-weight reduced-size degaussing system that comprises a plurality of degaussing coils arranged in a plurality of axes. An electrical current is passed through the plurality of coils to create a degaussing field. The degaussing coils comprise a high temperature superconductor material, the coils cooled by a single-phase gaseous cryogen.
    Type: Grant
    Filed: April 19, 2007
    Date of Patent: November 18, 2008
    Assignee: The United States of America as represented by the Secretary of the Navy
    Inventors: Brian K. Fitzpatrick, Thomas H. Fikse, William A. Lynch
  • Patent number: 7415971
    Abstract: In a control circuit for at least one actuator, in particular for a capacitive actuator of an injection system of an internal combustion engine, a control current can be applied to the actuator. The control circuit has an inductor, e.g., having a core and having multiple windings, the windings being designed and connected to the control circuit such that a control current flowing into the actuator and a control current flowing out of the actuator each flow through different windings of the inductor, and a magnetic flux induced in the inductor or its core by the control current flowing into the actuator and a magnetic flux induced in the inductor or its core by the control current flowing out of the actuator mutually compensate one another.
    Type: Grant
    Filed: June 23, 2005
    Date of Patent: August 26, 2008
    Assignee: Robert Bosch GmbH
    Inventors: Joerg Reineke, Armin Wiedergut, Karl Schweiger, Karl Farkas, Karl-Heinz Schmidt
  • Publication number: 20080030916
    Abstract: This unit is intermittent duty, small, and light weight. Use of a thyristor(s) control reduces the unit's energy consumption through reduced AC input voltage while still producing sufficient demagnetizing power and effective demagnetizing results. This principle may be applied to ANY and ALL sizes of demagnetizing coils. With the burst control we can achieve same demagnetizing power and reduce overall power consumption of the demagnetizing coil(s) reducing size and weight of the coil(s). For this intermittent duty coil(s) the power consumption is reduced by over 40% and heating rate reduced which allows approx. 40% longer continuous running time.
    Type: Application
    Filed: July 26, 2007
    Publication date: February 7, 2008
    Inventors: Elvir Kahrimanovic, Kenneth M. Littwin
  • Patent number: 7324321
    Abstract: A degaussing apparatus having permanent magnets employing common center poles arranged to obtain a flux level gauss of twice the normal level by arranging permanent magnets to create an enhanced center pole effect having an increased flux path as compared to the use of complimentary permanent magnets. The magnets are rotatably mounted in a nonferrous housing allowing placement of magnetic materials, such as a hard drive, thereon. The magnets are rotated within the housing by use of an electric drive motor. The magnets are maintained a predetermined distance from the magnetic materials to be degaussed by use of a spacer, preferably a series of rollers. In operation, the magnetic material is placed upon the housing and upon operation of the electric drive motor, the magnets are rotated in a 360° pattern causing degaussing of the magnetic material and complete destruction of hard drive heads and coils.
    Type: Grant
    Filed: August 22, 2006
    Date of Patent: January 29, 2008
    Inventor: William E. Olliges
  • Publication number: 20080013245
    Abstract: A permanent magnet degausser includes at least one magnetic field generator comprising magnetic elements arranged near a media conveyance path and a conveyor for transporting magnetic media through a magnetic media conveyance path. A passive belt or protector plate may be provided to assist the passage of the magnetic media through the applied magnetic field. The conveyor may be a continuous motion conveyor belt including cleats for holding the magnetic media or a reciprocal media conveyor including magnetic storage media bin. The magnetic field generator may include permanent magnets of varying intrinsic coercivities and/or remanences.
    Type: Application
    Filed: July 14, 2006
    Publication date: January 17, 2008
    Inventors: Robert A. Schultz, Leroy D. Thiel
  • Publication number: 20080013244
    Abstract: A permanent magnet degausser includes at least one magnetic field generator comprising magnetic elements arranged near a media conveyance path and a conveyor for transporting magnetic media through a magnetic media conveyance path. A passive belt or protector plate may be provided to assist the passage of the magnetic media through the applied magnetic field. The conveyor may be a continuous motion conveyor belt including cleats for holding the magnetic media or a reciprocal media conveyor including magnetic storage media bin. The magnetic field generator may include permanent magnets of varying intrinsic coercivities and/or remanences.
    Type: Application
    Filed: July 14, 2006
    Publication date: January 17, 2008
    Inventors: Robert A. Schultz, Leroy D. Thiel
  • Publication number: 20070247776
    Abstract: Embodiments in accordance with the present invention provide a degaussing device and a degaussing method capable of efficiently degaussing a magnetic disk, especially, a magnetic disk of the perpendicular magnetic recording system, without resorting to a magnetic field of a high intensity. Embodiments in accordance with the present invention provide a degaussing method of degaussing a magnetic disk not yet installed in a magnetic disk drive by applying an external magnetic field to the magnetic disk by a degaussing device. In accordance with one embodiment, the method includes disposing the magnetic disk in the degaussing device such that the direction of an external magnetic field is inclined at an angle to the axis of easy magnetization of the magnetic disk.
    Type: Application
    Filed: April 24, 2007
    Publication date: October 25, 2007
    Applicant: Hitachi Global Storage Technologies Netherlands B.V.
    Inventors: Hitoshi Tamura, Hiroki Mori, Mitsuru Hamaguchi, Kunihiko Mine, Takehiko Hamaguchi
  • Patent number: 7265925
    Abstract: A recorded data eraser 1 defines therein a cavity 2 for insertion of a hard disk drive 20 in the cavity 2 and includes a coil 4 being arranged around the cavity 2 so as to encircle the hard disk drive 20 when the hard disk drive 20 is inserted in the cavity 2, and a DC power supply circuit 8 for producing a magnetic field in the coil 4.
    Type: Grant
    Filed: May 7, 2002
    Date of Patent: September 4, 2007
    Assignee: Orient Instrument Computer Co. Ltd.
    Inventor: Tomoaki Ito
  • Patent number: 7196894
    Abstract: The method according to the invention for demagnetization is effected in two separate steps. Firstly magnetically hard locations, such as weld seams, pressure locations etc., of an object to be demagnetized is pre-treated locally with high fields by way of choke coils in an alternating field. These magnetically hard locations are at least partly demagnetized by way of this. Subsequently the complete demagnetization is effected in a decisive second step. The object remains for a certain time in an alternating field. Now the alternating field is stepped down in that the current in a series oscillation circuit is stepped down in a current-controlled manner with two coils.
    Type: Grant
    Filed: June 25, 2003
    Date of Patent: March 27, 2007
    Inventors: Albert Maurer, Urs Meyer
  • Patent number: 7164569
    Abstract: A bulk degaussing system for the erasure of magnetic storage media by means of permanent magnets. The bulk degaussing system includes a rotatably mounted carousel and an angular displacement means that angularly displaces the carousel through a predetermined angle after passage of the carousel through a degaussing gap.
    Type: Grant
    Filed: June 30, 2004
    Date of Patent: January 16, 2007
    Assignee: Data Security, Inc.
    Inventors: LeRoy D. Thiel, Robert A. Schultz
  • Patent number: 7120003
    Abstract: The circuit arrangement has a mains connection, a mains switch with two switching contacts, a demagnetization coil and a switch-mode power supply, which contains a driver circuit for producing a control voltage for the switching transistor of the switch-mode power supply. A first switching contact of the mains switch is arranged between the mains connection and the demagnetization coil in order to switch the demagnetization coil on and off, and the second switching contact is connected to a supply or control voltage for the driver circuit, in order to switch off the switch-mode power supply. In consequence, a power factor coil can be used between the mains connection and the switch-mode power supply for power factor correction, without the mains switch being loaded by the inductance of the power factor coil.
    Type: Grant
    Filed: April 12, 2003
    Date of Patent: October 10, 2006
    Assignee: Thomson Licensing
    Inventors: Wolfgang Hermann, John Stolte, Jean-Paul Louvel
  • Patent number: 7119691
    Abstract: A method and apparatus to deactivate an EAS security tag are described.
    Type: Grant
    Filed: October 17, 2003
    Date of Patent: October 10, 2006
    Assignee: Sensormatic Electronics Corporation
    Inventor: Steven V. Leone
  • Patent number: 7079345
    Abstract: Demagnetizing magnetic media for recording data in a data storage device includes placing the magnetic media in a magnetic field at a first strength, and gradually reducing the magnetic field to a second strength to essentially eliminate net magnetization in the magnetic media.
    Type: Grant
    Filed: January 17, 2002
    Date of Patent: July 18, 2006
    Assignee: Maxtor Corporation
    Inventors: Hai Chi Nguy, Steven Lambert, Steven Marshall, George H. Bellesis
  • Patent number: 7073513
    Abstract: A system and method of controlling movement of magnetic material with at least first and second high temperature superconductors at spaced locations. A plurality of solenoids are associated with the superconductors to induce a persistent currents in preselected high temperature superconductors establishing a plurality of magnetic fields in response to pulsed currents introduced to one or more of the solenoids. Control mechanism in communication with said solenoids and/or said high temperature superconductors are used to demagnetize selected ones of the high temperature superconductors to reduce the magnetic fields substantially to zero. Magnetic material is moved between magnetic fields by establishing the presence thereof and thereafter reducing magnetic fields substantially to zero and establishing magnetic fields in other superconductors arranged in a predetermined configuration.
    Type: Grant
    Filed: May 27, 2003
    Date of Patent: July 11, 2006
    Assignee: The University of Chicago
    Inventors: Yung Sheng Cha, John R. Hull, Thomas R. Askew
  • Patent number: 7064948
    Abstract: A degaussing system for magnetic media is provided, the system comprising an erasing head connected to an LC circuit and the erasing head including an elongated form around which a coil is wound. The coil has two segments which are spaced apart a distance to provide adjustment of the electrical and/or magnetic properties of the coil.
    Type: Grant
    Filed: March 21, 2003
    Date of Patent: June 20, 2006
    Assignee: Data Security, Inc.
    Inventors: Robert A. Schultz, LeRoy D. Thiel
  • Patent number: 7050255
    Abstract: A disk erase apparatus for erasing information on one or more disks in a disk drive uses a high strength magnetic field to erase the disks while the disks are in the HDD assembly. The design of the head disk enclosure provides a reduced thickness in a localized region over the disks. This allows a narrower working magnetic gap of the HDD level disk erase apparatus. The localized region of the HDD may be a formed indentation on the top cover, elimination of flange, and reduced floor thickness of the HDD base.
    Type: Grant
    Filed: September 29, 2003
    Date of Patent: May 23, 2006
    Assignee: Hitachi Global Storage Technologies Netherlands B.V.
    Inventors: Kirk Price, Neal Bertram Schirle
  • Patent number: 6965505
    Abstract: At a ship's magnetic silencing facility, calibration measurements are taken of onboard magnetic fields, and the off-board magnetic signature is minimized through an iterative degaussing process. Current data associated with the signature minimization is retained by a processor-controller implemented, along with degaussing coils and other apparatus, in a CLDG system effectuated onboard in a manner continually adaptive to changing conditions while voyaging. According to the CLDG methodology: Real time measurements are taken of the onboard magnetic fields, and are modified to account for the degaussing coils' magnetic effects. Via least squares fit mathematics, scale factors are calculated based on the relationship between (i) the real time measurements (as modified) of the onboard magnetic fields and (ii) the calibration measurements of the onboard magnetic fields.
    Type: Grant
    Filed: May 30, 2003
    Date of Patent: November 15, 2005
    Assignee: The United States of America as represented by the Secretary of the Navy
    Inventors: Richard M. Mack, Robert A. Wingo
  • Patent number: 6946962
    Abstract: A method and apparatus to deactivate an EAS security tag are described.
    Type: Grant
    Filed: October 29, 2003
    Date of Patent: September 20, 2005
    Assignee: Sensormatic Electronics Corporation
    Inventor: Steven V. Leone