Specifics Of Biasing Or Erasing Patents (Class 360/66)
  • Patent number: 10371742
    Abstract: A computer-implemented method includes, by one or more processors in electronic communication with a tunneling magnetoresistive sensor, wherein the tunneling magnetoresistive sensor is a component of a magnetic storage drive configured to read magnetic data from a magnetic storage medium, detecting a short across the tunneling magnetoresistive sensor, measuring a change in resistance of the tunneling magnetoresistive sensor, measuring a change in voltage amplitude for the tunneling magnetoresistive sensor, and dividing said change in voltage amplitude by said change in resistance to yield a ratio. The computer-implemented method further includes, responsive to the ratio being greater than a predetermined ratio threshold, determining that the short is caused by a magnetic shunt. A corresponding computer program product and computer system are also disclosed.
    Type: Grant
    Filed: December 29, 2017
    Date of Patent: August 6, 2019
    Assignee: International Business Machines Corporation
    Inventors: Robert G. Biskeborn, Wlodzimierz S. Czarnecki, Icko E. T. Iben, Hugo E. Rothuizen
  • Patent number: 10371743
    Abstract: A computer-implemented method includes, by one or more processors in electronic communication with a tunneling magnetoresistive sensor, wherein the tunneling magnetoresistive sensor is a component of a magnetic storage drive configured to read magnetic data from a magnetic storage medium, detecting a short across the tunneling magnetoresistive sensor, measuring a change in resistance of the tunneling magnetoresistive sensor, measuring a change in voltage amplitude for the tunneling magnetoresistive sensor, and dividing said change in voltage amplitude by said change in resistance to yield a ratio. The computer-implemented method further includes, responsive to the ratio being greater than a predetermined ratio threshold, determining that the short is caused by a magnetic shunt. A corresponding computer program product and computer system are also disclosed.
    Type: Grant
    Filed: December 30, 2017
    Date of Patent: August 6, 2019
    Assignee: International Business Machines Corporation
    Inventors: Robert G. Biskeborn, Wlodzimierz S. Czarnecki, Icko E. T. Iben, Hugo E. Rothuizen
  • Patent number: 10361735
    Abstract: A method of operating a near-field communication (NFC) circuit, the method including: receiving an interference signal and a data signal through an antenna; adjusting magnitudes of the received interference signal and the received data signal; down-converting frequencies of the interference signal and the data signal, the magnitudes of which are adjusted; filtering the data signal by removing the frequency down-converted interference signal; and adjusting a magnitude of the filtered data signal. The adjusting of the magnitudes of the received interference signal and the received data signal may include adjusting the magnitudes of the interference signal and the data signal such that linearity of the data signal is maintained during signal processing performed on the interference signal and the data signal in the down-converting of the frequencies of the interference signal and the data signal, the filtering of the data signal, and the adjusting of the magnitude of the filtered data signal.
    Type: Grant
    Filed: May 25, 2017
    Date of Patent: July 23, 2019
    Assignee: SAMSUNG ELECTRONICS CO., LTD.
    Inventors: Seong-sik Myoung, Jun-ho Kim, Il-jong Song
  • Patent number: 10242699
    Abstract: A single magnetic pulse degaussing apparatus for use in erasing information contained on magnetic recording or storage media. A degaussing chamber for receipt of magnetic forces above 2.0 Tesla is accessible by upper and lower rotary actuated doors. The internal flux of a coil is measured by the current passing through the coil during the discharge cycle to provide a flux versus time measurements. The measurements are inserted into a performance verification algorithm to assure sufficient time for media destruction has taken place before releasing the media from the degaussing chamber.
    Type: Grant
    Filed: May 23, 2018
    Date of Patent: March 26, 2019
    Assignee: Phiston Technologies, Inc.
    Inventors: M. Ali Ebadian, Raul Travieso
  • Patent number: 10181335
    Abstract: A method and system for cleaning and/or burnishing an article. The article is operated on by a burnishing object having one more cutting edges and one or more heating surfaces. The article rotates relative to the burnishing head and the cutting edges remove asperities from the article. The heating surface can be activated and can optionally protrude from the burnishing head to further reduce roughness of the surface of the article as the article is rotating relative to the head. The cutting edges and heating surfaces can be configured in shape and size (i.e., geometry) to accommodate the article.
    Type: Grant
    Filed: June 4, 2008
    Date of Patent: January 15, 2019
    Assignee: SEAGATE TECHNOLOGY LLC
    Inventors: Shashi Bhushan Agarwal, Huan Tang, Jing Gui
  • Patent number: 10056098
    Abstract: A data storage device is disclosed comprising a head actuated over a disk, wherein the head comprises a first sensor element and a second sensor element. When configured into a first single-ended mode, a bias signal is applied to the first sensor element to generate a first single-ended output signal based on a response of the first sensor element, and when configured into a second single-ended mode, the bias signal is applied to the second sensor element to generate a second single-ended output signal based on a response of the first sensor element. When configured into a differential mode, the bias signal is concurrently applied to the first sensor element and the second sensor element to generate a differential output signal based on a response of the first sensor element and the second sensor element.
    Type: Grant
    Filed: November 29, 2017
    Date of Patent: August 21, 2018
    Assignee: Western Digital Technologies, Inc.
    Inventors: Sukumar Rajauria, Erhard Schreck, John T. Contreras, Joey M. Poss, Rehan A. Zakai, Robert Smith, Barry C. Stipe
  • Patent number: 9984712
    Abstract: The magnetic tape device includes: a magnetic tape; and a servo head, in which a magnetic tape transportation speed of the magnetic tape device is equal to or lower than 18 m/sec, the servo head is a magnetic head including a tunnel magnetoresistance effect type element as a servo pattern reading element, the magnetic tape includes a non-magnetic support, and a magnetic layer including ferromagnetic powder and a binding agent on the non-magnetic support, the magnetic layer includes a servo pattern, and a contact angle with respect to 1-bromonaphthalene measured regarding a surface of the magnetic layer is 48.0° to 53.0°.
    Type: Grant
    Filed: December 26, 2017
    Date of Patent: May 29, 2018
    Assignee: FUJIFILM Corporation
    Inventors: Eiki Ozawa, Tetsuya Kaneko, Norihito Kasada
  • Patent number: 9915697
    Abstract: A computer-implemented method includes, by one or more processors in electronic communication with a tunneling magnetoresistive sensor, wherein the tunneling magnetoresistive sensor is a component of a magnetic storage drive configured to read magnetic data from a magnetic storage medium, detecting a short across the tunneling magnetoresistive sensor, measuring a change in resistance of the tunneling magnetoresistive sensor, measuring a change in voltage amplitude for the tunneling magnetoresistive sensor, and dividing said change in voltage amplitude by said change in resistance to yield a ratio. The computer-implemented method further includes, responsive to the ratio being greater than a predetermined ratio threshold, determining that the short is caused by a magnetic shunt. A corresponding computer program product and computer system are also disclosed.
    Type: Grant
    Filed: July 21, 2017
    Date of Patent: March 13, 2018
    Assignee: International Business Machines Corporation
    Inventors: Robert G. Biskeborn, Wlodzimierz S. Czarnecki, Icko E. T. Iben, Hugo E. Rothuizen
  • Patent number: 9812161
    Abstract: A sensor supported by a head transducer has a temperature coefficient of resistance (TCR) and a sensor resistance. The sensor operates at a temperature above ambient and is responsive to changes in sensor-medium spacing. Conductive contacts connected to the sensor have a contact resistance and a cross-sectional area adjacent to the sensor larger than that of the sensor, such that the contact resistance is small relative to the sensor resistance and negligibly contributes to a signal generated by the sensor. A multiplicity of head transducers each support a TCR sensor and a power source can supply bias power to each sensor of each head to maintain each sensor at a fixed temperature above an ambient temperature in the presence of heat transfer changes impacting the sensors. A TCR sensor of a head transducer can include a track-oriented TCR sensor wire for sensing one or both of asperities of the medium.
    Type: Grant
    Filed: August 30, 2016
    Date of Patent: November 7, 2017
    Assignee: SEAGATE TECHNOLOGY LLC
    Inventors: Manuel Charles Anaya-Dufresne, Brian William Karr, Gary Joseph Kunkel, Zhen Wei
  • Patent number: 9728222
    Abstract: In one general embodiment, an apparatus includes a plurality of read transducers arranged in an array, and a plurality of biasing circuits. Each biasing circuit is coupled to a unique one of the read transducers. Each biasing circuit is configured to selectively reverse a direction of a read current applied to the read transducer associated therewith.
    Type: Grant
    Filed: May 19, 2016
    Date of Patent: August 8, 2017
    Assignee: International Business Machines Corporation
    Inventors: Robert G. Biskeborn, Ho-Yiu Lam, Jason Liang
  • Patent number: 9678137
    Abstract: Methods and systems for monitoring contact joint integrity in an information handling system may include precisely monitoring a change in resistance of a resistive element associated with a contact joint. The change in resistance of the resistive element may be indicative of the integrity of the contact joint. The resistance may be measured using a modulated current source and by demodulating a voltage signal resulting from the modulated current flowing across the resistive element.
    Type: Grant
    Filed: February 26, 2014
    Date of Patent: June 13, 2017
    Assignee: Dell Products L.P.
    Inventors: Bhyrav M. Mutnury, Sandor Farkas, Wallace H. Ables
  • Patent number: 9559682
    Abstract: A circuit is suggested comprising an electronic switching element, a logic unit coupled to control the electronic switching element, and a counter unit coupled to the logic unit, wherein the counter unit comprises a counter and an internal power supply.
    Type: Grant
    Filed: January 12, 2015
    Date of Patent: January 31, 2017
    Assignee: Infineon Technologies AG
    Inventors: Florian Brugger, Robert Illing, Alexander Mayer, Christian Djelassi
  • Patent number: 9530440
    Abstract: Embodiments of the present invention provide methods, systems, and computer program products for compensating for loss of current through shorted tunneling magnetoresistance (TMR) sensors. In one embodiment, for a magnetic head having multiple TMR read sensors, a first voltage limit is set for most parts and a second voltage limit is set for all of the parts. A number of TMR read sensors which are allowed to function between the first and the second voltage limits is determined using a probability algorithm, which determines the probability that the application of the second voltage limit will result in a dielectric breakdown within an expected lifetime of a drive is below a threshold value. For the number of TMR read sensors which are allowed to function at voltages between the first and second voltage limits, a determined subset of those sensors are then allowed to function at the second voltage limit.
    Type: Grant
    Filed: October 30, 2015
    Date of Patent: December 27, 2016
    Assignee: International Business Machines Corporation
    Inventors: Said A. Ahmad, Wlodzimierz S. Czarnecki, Ernest S. Gale, Icko E. T. Iben
  • Patent number: 9497051
    Abstract: A receiver that is selectively reconfigurable in a first and a second selectable configuration is disclosed. Configured in the first selectable configuration, the receiver may provide a low impedance input. Configured in the first selectable configuration, a low common-mode input signal may be received. In an embodiment, configured in the first selectable configuration, signaling technologies, such as a Near Ground Signaling (NGS) may be received. Configured in the second selectable configuration, the receiver may provide a high impedance input. Configured in the second selectable configuration, a high common-mode input signal may be received. In an embodiment, configured in the second selectable configuration, signaling technologies, such as a Low Voltage Differential Signaling (LVDS), Pseudo Open Drain Logic (PODL) signaling, Differential Rambus Signaling Level (DRSL), and/or Series Stub Terminated Logic (SSTL) signaling may be received.
    Type: Grant
    Filed: May 7, 2015
    Date of Patent: November 15, 2016
    Assignee: Rambus Inc.
    Inventor: Huy M. Nguyen
  • Patent number: 9460004
    Abstract: A memory erasing method and a memory controller and a memory storage apparatus using the same are provided. The memory erasing method includes following steps. Physical blocks of a rewritable non-volatile memory module of the memory storage apparatus are logically grouped into at least a data area and a spare area. After the memory storage apparatus is powered on, an erase mark is configured for each of the physical blocks in the spare area, and each of the erase marks is initially set to an unerased state. After the memory storage apparatus enters a standby state, whether an erase command is executed on the physical blocks in the spare area is determined according to the erase marks. Thereby, the memory erasing method can effectively shorten the time for the memory storage apparatus to enter the standby state after the memory storage apparatus is powered on.
    Type: Grant
    Filed: August 19, 2011
    Date of Patent: October 4, 2016
    Assignee: PHISON ELECTRONICS CORP.
    Inventor: Wei-Chen Teo
  • Patent number: 9449629
    Abstract: A sensor supported by a head transducer has a temperature coefficient of resistance (TCR) and a sensor resistance. The sensor operates at a temperature above ambient and is responsive to changes in sensor-medium spacing. Conductive contacts connected to the sensor have a contact resistance and a cross-sectional area adjacent to the sensor larger than that of the sensor, such that the contact resistance is small relative to the sensor resistance and negligibly contributes to a signal generated by the sensor. A multiplicity of head transducers each support a TCR sensor and a power source can supply bias power to each sensor of each head to maintain each sensor at a fixed temperature above an ambient temperature in the presence of heat transfer changes impacting the sensors. A TCR sensor of a head transducer can include a track-oriented TCR sensor wire for sensing one or both of asperities of the medium.
    Type: Grant
    Filed: August 17, 2015
    Date of Patent: September 20, 2016
    Assignee: SEAGATE TECHNOLOGY LLC
    Inventors: Manuel Charles Anaya-Dufresne, Brian William Karr, Gary Joseph Kunkel, Zhen Wei
  • Patent number: 9437219
    Abstract: An apparatus for two-dimensional magnetic recording includes a storage medium, an array of magnetoresistive read heads disposed adjacent the storage medium and spaced to read a data track, a number of leads connected to the array of magnetoresistive read heads, and number of bias circuits connected to the array of read heads by the leads. The bias circuits can be configured to independently bias each of the array of read heads with the array of read heads connected in series or in parallel.
    Type: Grant
    Filed: September 10, 2015
    Date of Patent: September 6, 2016
    Assignee: Avago Technologies General IP (Singapore) Pte. Ltd.
    Inventors: Ross S. Wilson, Scott M. O'Brien, Jeffrey A. Gleason, Jason P. Brenden, Jaydip Bhaumik, David Fitzgerald
  • Patent number: 9418685
    Abstract: Embodiments of the present invention provide methods, systems, and computer program products for compensating for loss of current through shorted tunneling magnetoresistance (TMR) sensors. In one embodiment, for a magnetic head having multiple TMR read sensors, a first voltage limit is set for most parts and a second voltage limit is set for all of the parts. A number of TMR read sensors which are allowed to function between the first and the second voltage limits is determined using a probability algorithm, which determines the probability that the application of the second voltage limit will result in a dielectric breakdown within an expected lifetime of a drive is below a threshold value. For the number of TMR read sensors which are allowed to function at voltages between the first and second voltage limits, a determined subset of those sensors are then allowed to function at the second voltage limit.
    Type: Grant
    Filed: December 18, 2015
    Date of Patent: August 16, 2016
    Assignee: International Business Machines Corporation
    Inventors: Said A. Ahmad, Wlodzimierz S. Czarnecki, Ernest S. Gale, Icko E. T. Iben
  • Patent number: 9361909
    Abstract: The embodiments disclose an alternating current (AC) erase process configured to cancel out existing polarity of stack magnetic features on both sides of the stack and an AC reset process configured to initialize the polarity of the device stack magnetic features of both sides of a stack configured to create a uniform polarity.
    Type: Grant
    Filed: October 16, 2013
    Date of Patent: June 7, 2016
    Assignee: Seagate Technology LLC
    Inventor: Stephen Keith McLaurin
  • Patent number: 9336804
    Abstract: Systems and methods relating generally to sensing information, and more particularly to systems and methods for utilizing multiple readers to sense information.
    Type: Grant
    Filed: September 16, 2013
    Date of Patent: May 10, 2016
    Assignee: Avago Technologies General IP (Singapore) Pte. Ltd.
    Inventor: Bruce A. Wilson
  • Patent number: 9311937
    Abstract: Systems and methods are provided for calibrating signals retrieved from a storage device using a first reader and a second reader. The systems and methods further include reading a first signal using the first reader and a second signal using the second reader. Control circuitry computes a calibration metric associated with the first reader and the second reader based on the combination of the first signal and the second signal. At least one of the first signal and the second signal is subsequently decoded based in part on the computed calibration metric.
    Type: Grant
    Filed: July 15, 2014
    Date of Patent: April 12, 2016
    Assignee: Marvell World Trade Ltd.
    Inventors: Qiyue Zou, Michael Madden, Gregory Burd
  • Patent number: 9286916
    Abstract: A data writing device may be constructed and operated with at least a data writer that has at least a write pole and a magnetic feature. A controller may selectively activate the magnetic feature to magnetically oscillate and produce a radio frequency signal proximal the write pole on an air bearing surface (ABS).
    Type: Grant
    Filed: August 26, 2014
    Date of Patent: March 15, 2016
    Assignee: Seagate Technology LLC
    Inventors: Kirill Rivkin, Mourad Benakli, Huaqing Yin
  • Patent number: 9263069
    Abstract: A testing device tests a magnetic head with a read head structure including a read head element while applying an external magnetic field to the magnetic head. The testing device receives signals from the read head element and processes the signals to generate a spectral power density for the signals. The spectral power density is characterized for at least one frequency range. The characterization of the spectral power density is used to determine a characteristic of noise from the read head structure. The signals from the read head may be received with different applied magnetic fields and/or before or while thermally exciting the magnetic head. Additionally, a histogram of the signals may be generated and used to determine a second characteristic of the noise.
    Type: Grant
    Filed: March 11, 2013
    Date of Patent: February 16, 2016
    Assignee: Infinitum Solutions, Inc.
    Inventor: Alexander M. Taratorin
  • Patent number: 9251824
    Abstract: An apparatus and associated method employing a bridge circuit having first and second microactuators attached to the apparatus. An excitation source is configured to independently drive each of the microactuators. A computation module is connected to the bridge circuit and is configured to independently measure an electrical output of each microactuator. The computation module uses the electrical outputs to characterize a bimodal modulation of the apparatus.
    Type: Grant
    Filed: January 28, 2015
    Date of Patent: February 2, 2016
    Assignee: SEAGATE TECHNOLOGY LLC
    Inventors: Vijay Kumar, Narayanan Ramakrishnan
  • Patent number: 9182245
    Abstract: A resistive sensor read-out apparatus is disclosed. In one embodiment, the resistive sensor read-out apparatus comprises an active sensor, a reference element, a bias circuit, a current-to-voltage converter, an analog-to-digital converter and a calibration processor. The bias circuit is coupled to the active sensor and the reference element and configured to calibrate one or more mismatches between the active sensor and the reference element. The current-to-voltage converter is coupled to an output of the bias circuit. The analog-to-digital converter is coupled to an output of the current-to-voltage converter. The calibration processor is coupled to an output of the analog-to-digital converter and configured to estimate an error caused by limited resolution mismatch calibration. The calibration processor is also configured to at least partially control calibration performed at the bias circuit based on the error.
    Type: Grant
    Filed: November 5, 2010
    Date of Patent: November 10, 2015
    Assignee: HITTITE MICROWAVE CORPORATION
    Inventors: Ivar Lokken, Christian Hergot
  • Patent number: 9175942
    Abstract: A magnetic sensor system includes a magnetic field generation unit for generating a target magnetic field and a magnetic sensor for detecting the target magnetic field, and is selectable between an operating state and a non-operating state. The magnetic sensor has a magnetic detection element including a magnetic layer whose magnetization direction varies according to the direction of the target magnetic field in a reference position. When in the operating state, the direction of the target magnetic field in the reference position varies when viewed from the magnetic sensor. When in the non-operating state, the direction of the target magnetic field in the reference position does not vary when viewed from the magnetic sensor and the magnetization direction of the magnetic layer is pinned in a first direction. The magnetic layer has an induced magnetic anisotropy that is imparted in advance to the magnetic layer.
    Type: Grant
    Filed: January 11, 2013
    Date of Patent: November 3, 2015
    Assignee: TDK CORPORATION
    Inventors: Kazuya Watanabe, Hiraku Hirabayashi
  • Patent number: 9070395
    Abstract: According to one embodiment, there is provided a magnetic disk device including a magnetic disk, a magnetic head, a heater, and a control unit. The magnetic head reads out information recorded on the magnetic disk. The heater is configured to adjust a magnetic spacing of the magnetic head from the magnetic disk. The control unit is configured to change a bias amount of the magnetic head according to setting of current flow through the heater.
    Type: Grant
    Filed: May 28, 2014
    Date of Patent: June 30, 2015
    Assignee: Kabushiki Kaisha Toshiba
    Inventor: Koji Ishii
  • Patent number: 9054916
    Abstract: A receiver that is selectively reconfigurable in a first and a second selectable configuration is disclosed. Configured in the first selectable configuration, the receiver may provide a low impedance input. Configured in the first selectable configuration, a low common-mode input signal may be received. In an embodiment, configured in the first selectable configuration, signaling technologies, such as a Near Ground Signaling (NGS) may be received. Configured in the second selectable configuration, the receiver may provide a high impedance input. Configured in the second selectable configuration, a high common-mode input signal may be received. In an embodiment, configured in the second selectable configuration, signaling technologies, such as a Low Voltage Differential Signaling (LVDS), Pseudo Open Drain Logic (PODL) signaling, Differential Rambus Signaling Level (DRSL), and/or Series Stub Terminated Logic (SSTL) signaling may be received.
    Type: Grant
    Filed: April 8, 2013
    Date of Patent: June 9, 2015
    Assignee: Rambus Inc.
    Inventor: Huy M. Nguyen
  • Publication number: 20150131178
    Abstract: The magnetic data eraser includes: a mounting and immobilizing tray on which a magnetic recording medium is mounted, the mounting tray being inclined at an angle of 60±10 degrees to the horizontal; a magnetizer that is encircled by a magnetizing coil, the magnetizer having a hollow portion into which the mounting and immobilizing tray is inserted; and a controller that causes an electric current to flow as an excitation current through the magnetizing coil, the excitation current generating a magnetic field that erases data stored in the magnetic recording medium.
    Type: Application
    Filed: July 28, 2014
    Publication date: May 14, 2015
    Inventor: Tadashi Honda
  • Publication number: 20150103430
    Abstract: A bond pad set includes at least one ground pad and at least one electrical bond pad configured to bias and send/receive signals. The bond pad set is electrically connected to a multiplicity of electrical components. At least one electrical bond pad of the bond pad set is shared between two or more of the electrical components.
    Type: Application
    Filed: October 10, 2013
    Publication date: April 16, 2015
    Applicant: Seagate Technology LLC
    Inventors: Jason Bryce Gadbois, Declan Macken, Karsten Klarqvist
  • Patent number: 8988815
    Abstract: Magnetoresistive (MR) bias is dynamically controlled in a tape drive using a processor device. Median tape head amplitude is monitored during a calibration operation, as measured across all tracks of the tape head, against predetermined thresholds of the tape drive for determining if the median tape head amplitude is below the threshold value. Upon determining the median tape head amplitude is below the threshold value during the calibration operation, a reference MR bias and a MR bias range is dynamically adjusted, during the calibration operation, for increasing the median tape head amplitude.
    Type: Grant
    Filed: May 7, 2014
    Date of Patent: March 24, 2015
    Assignee: International Business Machines Corporation
    Inventors: Said A. Ahmad, Josephine F. Bayang, Eric R. Christensen, Ernest S. Gale
  • Patent number: 8983789
    Abstract: A bias calibration circuit includes a first current source that can provide a majority biasing current, sufficient to provide most but not all of a desired bias voltage across a sensor. A second current source can provide a remaining amount of biasing current (minority biasing current) to provide a bias voltage across the sensor. In some embodiments, the current sources are programmable and codes are determined for programming the first and second current sources. The codes can be stored in a memory.
    Type: Grant
    Filed: July 14, 2011
    Date of Patent: March 17, 2015
    Assignee: Marvell International Ltd.
    Inventor: Thart Fah Voo
  • Patent number: 8953267
    Abstract: Interface circuitry of a storage device or other type of processing device comprises a digital input detector and an adaptive power supply. The digital input detector comprises an input transistor. The adaptive power supply provides a variable supply voltage to the digital input detector that varies with a threshold voltage of the input transistor. In one embodiment, the variable supply voltage provided to the digital input detector by the adaptive power supply varies with the threshold voltage of the input transistor about a set point value determined as a function of an expected logic level of an input signal. For example, the set point value may be determined as a function of a minimum expected logic high input signal level. In such an arrangement, the input transistor is biased at or close to the threshold voltage for an input signal having the minimum expected logic high input signal level.
    Type: Grant
    Filed: November 1, 2011
    Date of Patent: February 10, 2015
    Assignee: LSI Corporation
    Inventor: Jonathan H. Fischer
  • Patent number: 8947803
    Abstract: A data storage device includes a recording medium including a data region for recording data and a nonvolatile recording unit distinct from the data region. In response to a request for executing erase processing with respect to the recording medium, first time information corresponding to initiation of the erase processing in the nonvolatile recording unit is stored, the erase processing after storing the first time information is executed, and second time information corresponding to completion of the erase processing is stored in the nonvolatile recording unit.
    Type: Grant
    Filed: February 26, 2014
    Date of Patent: February 3, 2015
    Assignee: Kabushiki Kaisha Toshiba
    Inventors: Teruji Yamakawa, Osamu Yoshida
  • Patent number: 8934189
    Abstract: An apparatus according to one embodiment includes a resistive link coupled to both an electrically conductive bus and an electrically conductive structure, the electrically conductive structure being positioned proximate to a media bearing surface. An apparatus according to another embodiment includes an array of transducers; an electrically conductive bus; and resistive links electrically coupled between the electrically conductive bus and at least one of: each of a plurality of electrically conductive structures, and at least some of the transducers.
    Type: Grant
    Filed: May 7, 2013
    Date of Patent: January 13, 2015
    Assignee: International Business Machines Corporation
    Inventor: Robert G. Biskeborn
  • Publication number: 20140368946
    Abstract: A method for detecting a contact event between a transducer and a recording medium is disclosed. The method includes positioning a transducer with respect to a recording medium, where the transducer includes a writer, a reader, a heater, and a thermally responsive sensor. The method further includes applying power to the heater to establish a fly height of the transducer; supplying a bias current through the thermally responsive sensor to generate a bias signal; measuring a root mean square (RMS) voltage VRMS of the thermally responsive sensor based on the bias signal; determining a threshold voltage VT; and detecting a contact event between the transducer and the medium based on VRMS being greater than VT.
    Type: Application
    Filed: June 17, 2013
    Publication date: December 18, 2014
    Inventors: Andy Chou, Quan Li, Chee Wee Cheng, Beng Theam Ko, Myint Ngwe
  • Patent number: 8896957
    Abstract: A disk drive is disclosed comprising a disk surface comprising a radius, a head operable to generate a read signal, and a voice coil motor (VCM) operable to actuate the head over the disk surface. A back electromotive force (BEMF) voltage generated by the VCM is measured. The VCM is controlled to move the head over substantially the entire radius of the disk surface in response to the BEMF voltage, and while moving the head the read signal from the head is processed to detect residual data recorded on the disk surface after erasing the disk surface.
    Type: Grant
    Filed: June 20, 2013
    Date of Patent: November 25, 2014
    Assignee: Western Digital Technologies, Inc.
    Inventors: Yap Han Ng, Charles A. Park, Songwut Jomthaisong, Siri S. Weerasooriya, Brian P. Rigney
  • Patent number: 8891195
    Abstract: A storage device includes a storage medium having a plurality of tracks of data. Reading apparatus for reading a current track of data that has been subject to previous encroachment to an extent from at least one adjacent track of data includes a write head that writes interfering data to the adjacent track of data while intentionally encroaching at least to that extent onto the current track of data, and circuitry that recovers data on the current track of data using the interfering data. A method for reading a current track of data, that has been subject to previous encroachment to an extent from at least one adjacent track of data, includes writing interfering data to the adjacent track of data while intentionally encroaching at least to that extent onto the current track of data, and recovering data on the current track of data using the interfering data.
    Type: Grant
    Filed: December 4, 2013
    Date of Patent: November 18, 2014
    Assignee: Marvell International Ltd.
    Inventors: Gregory Burd, Nitin Nangare
  • Patent number: 8873188
    Abstract: A hard disk drive or other storage device comprises a storage medium, a write head configured to write data to the storage medium, and control circuitry coupled to the write head. The control circuitry comprises degauss circuitry coupled to or otherwise associated with one or more write drivers. The degauss circuitry is configured to generate an asymmetric degauss signal to be applied to the write head. The asymmetric degauss signal has a waveform with upper and lower decay envelopes that are asymmetric about a specified degauss current level, such as a substantially zero current level.
    Type: Grant
    Filed: April 30, 2013
    Date of Patent: October 28, 2014
    Assignee: LSI Corporation
    Inventors: Boris Livshitz, Paul Mazur, Anamul Hoque, Jason S. Goldberg
  • Patent number: 8837074
    Abstract: A storage device includes a storage medium having a plurality of tracks of data. Reading apparatus for reading a current track of data that has been subject to previous encroachment to an extent from at least one adjacent track of data includes a write head that writes interfering data to the adjacent track of data while intentionally encroaching at least to that extent onto the current track of data, and circuitry that recovers data on the current track of data using the interfering data. A method for reading a current track of data, that has been subject to previous encroachment to an extent from at least one adjacent track of data, includes writing interfering data to the adjacent track of data while intentionally encroaching at least to that extent onto the current track of data, and recovering data on the current track of data using the interfering data.
    Type: Grant
    Filed: March 17, 2011
    Date of Patent: September 16, 2014
    Assignee: Marvell International, Ltd.
    Inventors: Gregory Burd, Nitin Nangare
  • Patent number: 8824087
    Abstract: A method and system for estimating a zero gain start (ZGS) bias in a read channel is disclosed. The method may include: receiving preamble samples within a fixed-length window selected for ZGS calculation; calculating an energy associated with a 2T frequency in the preamble samples; calculating an energy associated with non-2T frequencies in the preamble samples; and calculating the ZGS bias based on the energy associated with the 2T frequency in the preamble samples and the energy associated with non-2T frequencies in the preamble samples.
    Type: Grant
    Filed: August 2, 2012
    Date of Patent: September 2, 2014
    Assignee: LSI Corporation
    Inventors: Haotian Zhang, Scott Michael Dziak, Haitao Xia
  • Publication number: 20140240865
    Abstract: Magnetoresistive (MR) bias is dynamically controlled in a tape drive using a processor device. Median tape head amplitude is monitored during a calibration operation, as measured across all tracks of the tape head, against predetermined thresholds of the tape drive for determining if the median tape head amplitude is below the threshold value. Upon determining the median tape head amplitude is below the threshold value during the calibration operation, a reference MR bias and a MR bias range is dynamically adjusted, during the calibration operation, for increasing the median tape head amplitude.
    Type: Application
    Filed: May 7, 2014
    Publication date: August 28, 2014
    Applicant: INTERNATIONAL BUSINESS MACHINES CORPORATION
    Inventors: Said A. AHMAD, Josephine F. BAYANG, Eric R. CHRISTENSEN, Ernest S. GALE
  • Publication number: 20140240864
    Abstract: A hard disk drive or other storage device comprises a storage medium, a write head configured to write data to the storage medium, and control circuitry coupled to the write head. The control circuitry comprises degauss circuitry coupled to or otherwise associated with one or more write drivers. The degauss circuitry is configured to generate an asymmetric degauss signal to be applied to the write head. The asymmetric degauss signal has a waveform with upper and lower decay envelopes that are asymmetric about a specified degauss current level, such as a substantially zero current level.
    Type: Application
    Filed: April 30, 2013
    Publication date: August 28, 2014
    Applicant: LSI Corporation
    Inventor: LSI Corporation
  • Patent number: 8817409
    Abstract: The magnetic data eraser includes: a mounting and immobilizing tray on which a magnetic recording medium is mounted, the mounting tray being inclined at an angle of 60±10 degrees to the horizontal; a magnetizer that is encircled by a magnetizing coil, the magnetizer having a hollow portion into which the mounting and immobilizing tray is inserted; and a controller that causes an electric current to flow as an excitation current through the magnetizing coil, the excitation current generating a magnetic field that erases data stored in the magnetic recording medium.
    Type: Grant
    Filed: July 15, 2012
    Date of Patent: August 26, 2014
    Assignee: Tadashi Honda
    Inventor: Tadashi Honda
  • Patent number: 8817415
    Abstract: Magnetic storage tape and techniques for erasing and writing to magnetic storage tape having a perpendicular squareness greater than 50 percent and a longitudinal squareness less than 50 percent are described. In general, the magnetic tape may be biased with a remanence magnetization, or magnetic orientation, in any direction. One or two head systems may use various magnetic field patterns to create the desired remanence magnetization. Servo marks may have a remanence magnetization in an opposite magnetic orientation than that of the remaining bias on the servo track, e.g., substantially perpendicular to the magnetic tape. In some examples, a write head may alternate the direction of the magnetic field to continuously bias and write servo patterns to the magnetic tape. In addition, a symmetrical servo mark may be created in the magnetic tape with a write head having a gap width approximately equal to the length of the servo mark.
    Type: Grant
    Filed: June 13, 2011
    Date of Patent: August 26, 2014
    Assignee: Imation Corp.
    Inventors: Larold L. Olson, Douglas W. Johnson, Michael P. Sharrock
  • Patent number: 8804276
    Abstract: Magnetic storage tape and techniques for erasing and writing to magnetic storage tape having a perpendicular squareness greater than 50 percent and a longitudinal squareness less than 50 percent are described. In general, the magnetic tape may be biased with a remanence magnetization, or magnetic orientation, in any direction. One or two head systems may use various magnetic field patterns to create the desired remanence magnetization. Servo marks may have a remanence magnetization in an opposite magnetic orientation than that of the remaining bias on the servo track, e.g., substantially perpendicular to the magnetic tape. In some examples, a write head may alternate the direction of the magnetic field to continuously bias and write servo patterns to the magnetic tape. In addition, a symmetrical servo mark may be created in the magnetic tape with a write head having a gap width approximately equal to the length of the servo mark.
    Type: Grant
    Filed: June 13, 2011
    Date of Patent: August 12, 2014
    Assignee: Imation Corp.
    Inventors: Larold L. Olson, Douglas W. Johnson, Michael P. Sharrock
  • Patent number: 8797674
    Abstract: Magnetic storage tape and techniques for erasing and writing to magnetic storage tape having a perpendicular squareness greater than 50 percent and a longitudinal squareness less than 50 percent are described. In general, the magnetic tape may be biased with a remanence magnetization, or magnetic orientation, in any direction. One or two head systems may use various magnetic field patterns to create the desired remanence magnetization. Servo marks may have a remanence magnetization in an opposite magnetic orientation than that of the remaining bias on the servo track, e.g., substantially perpendicular to the magnetic tape. In some examples, a write head may alternate the direction of the magnetic field to continuously bias and write servo patterns to the magnetic tape. In addition, a symmetrical servo mark may be created in the magnetic tape with a write head having a gap width approximately equal to the length of the servo mark.
    Type: Grant
    Filed: June 13, 2011
    Date of Patent: August 5, 2014
    Assignee: Imation Corp.
    Inventors: Larold L. Olson, Douglas W. Johnson, Michael P. Sharrock
  • Patent number: 8767326
    Abstract: Magnetoresistive (MR) bias is dynamically controlled in a tape drive using a processor device. Upon determining head amplitude is below a threshold value, the MR bias is adjusted for increasing the head amplitude and extending the useful life span of the tape drive.
    Type: Grant
    Filed: August 28, 2012
    Date of Patent: July 1, 2014
    Assignee: Industrial Business Machines Corporation
    Inventors: Said Abdullah Ahmad, Josephine Faith Bayang, Eric Rolf Christensen, Ernest Stewart Gale
  • Patent number: 8760802
    Abstract: A system comprises a magnetic medium with a first magnetic gap adjacent a first side and a second magnetic gap adjacent a second side, opposite the first magnetic gap. The first magnetic gap generates first longitudinal and perpendicular field components. The second magnetic gap generates second longitudinal and perpendicular field components. The first and second longitudinal field components are substantially aligned along a recording layer of the magnetic medium, and the first and second perpendicular field components are substantially opposed across the recording layer of the magnetic medium.
    Type: Grant
    Filed: March 12, 2013
    Date of Patent: June 24, 2014
    Assignee: Imation Corp.
    Inventors: Stephen J. Rothermel, Douglas W. Johnson
  • Patent number: 8760790
    Abstract: Amplifier architectures are provided for current sensing applications. An amplifier includes a load device, an operational amplifier, a current source, and a bipolar transistor. The operational amplifier has a first input terminal connected to a first input node that receives an input current, and a second input terminal connected to a second input node that receives a reference voltage. The current source is connected to an output of the operational amplifier. The operational amplifier, the current source, and the bipolar transistor form a feedback loop that generates and maintains a bias voltage on the first input node based on the reference voltage applied to the second input node. The bipolar transistor amplifies the input current received on the first input node, and generates an amplified input current. The load device converts the amplified input current to an output voltage, wherein the output voltage is used to sense the input current.
    Type: Grant
    Filed: November 12, 2012
    Date of Patent: June 24, 2014
    Assignee: LSI Corporation
    Inventors: Brad A. Natzke, Cameron C. Rabe, Hong Jiang, Andrew P. Krebs, Jason P. Brenden