Controlling The Head Patents (Class 360/75)
  • Patent number: 10373639
    Abstract: The magnetic tape device includes a magnetic tape including a magnetic layer, in which an intensity ratio of a peak intensity of a diffraction peak of a (110) plane with respect to a peak intensity of a diffraction peak of a (114) plane of a hexagonal ferrite crystal structure obtained by an X-ray diffraction analysis of the magnetic layer by using an In-Plane method is 0.5 to 4.0, a vertical direction squareness ratio of the magnetic tape is 0.65 to 1.00, Ra measured regarding a surface of the magnetic layer is equal to or smaller than 2.0 nm, and a C—H derived C concentration calculated from a C—H peak area ratio of C1s spectra obtained by X-ray photoelectron spectroscopic analysis performed on the surface of the magnetic layer at a photoelectron take-off angle of 10 degrees is 45 to 65 atom %.
    Type: Grant
    Filed: March 14, 2018
    Date of Patent: August 6, 2019
    Assignee: FUJIFILM Corporation
    Inventors: Norihito Kasada, Eiki Ozawa
  • Patent number: 10365628
    Abstract: A positioning control device of an actuator provided with a strain wave gearing has a full-closed control system for feeding back a position of a load shaft, and driving and controlling a motor so as to position the load shaft at a target position. The full-closed control system has an H? compensator designed so that, when a generalized plant having angular transmission error in the strain wave gearing as a disturbance input is assumed, an H? norm of a transfer function from the disturbance input of the generalized plant to an evaluation output is a predetermined value or less. Mechanical vibration during positioning response caused by angular transmission error in the strain wave gearing can be reliably suppressed.
    Type: Grant
    Filed: September 27, 2016
    Date of Patent: July 30, 2019
    Assignees: Harmonic Drive Systems Inc., Nagoya Institute of Technology
    Inventors: Masafumi Yamamoto, Yoshifumi Okitsu, Makoto Iwasaki
  • Patent number: 10366719
    Abstract: A clearance heater of a write head is engaged with a boosted current that exceeds a steady-state current. The steady-state current causes the write head to maintain a desired clearance over a disk during writing, the boosted current being applied before a start of the writing. The boosted current is monotonically decreased before the start of the writing and the steady-state current is applied to the heater after the start of the writing.
    Type: Grant
    Filed: March 20, 2018
    Date of Patent: July 30, 2019
    Assignee: Seagate Technology LLC
    Inventors: Jason W. Riddering, Dustin Mark Cvancara, Kenneth A. Haapala, Eric John McCalla, Wenzhong Zhu, Bin Huang
  • Patent number: 10339021
    Abstract: Embodiments of the present disclosure relate to a method and an apparatus for operating a hybrid storage device, the hybrid storage device including a storage device of a first type and a storage device of a second type that is different from the first type, the method comprising: synchronously writing data in the storage device of the first type and the storage device of the second type. By using the embodiments of the present disclosure, the actual storage space may be increased, and the service life of the storage device may be prolonged.
    Type: Grant
    Filed: December 22, 2016
    Date of Patent: July 2, 2019
    Assignee: EMC IP Holding Company LLC
    Inventors: Xinlei Xu, Jian Gao, Lifeng Yang, Huadong Li, Changyu Feng
  • Patent number: 10319901
    Abstract: A spin-orbit torque type magnetization reversal element including a ferromagnetic metal layer with a varying magnetization direction; and spin-orbit torque wiring that extends in a first direction intersecting with a stacking direction of the ferromagnetic metal layer and that is joined to the ferromagnetic metal layer; wherein when viewed from the first direction, the spin-orbit torque wiring is asymmetrical in a second direction that is orthogonal to the first direction and the stacking direction, with respect to an axis that passes through a center, in the second direction, of the ferromagnetic metal layer.
    Type: Grant
    Filed: September 15, 2017
    Date of Patent: June 11, 2019
    Assignee: TDK CORPORATION
    Inventors: Tomoyuki Sasaki, Yohei Shiokawa
  • Patent number: 10304484
    Abstract: According to one embodiment, a servo write control apparatus is for a disk apparatus including a read element and a write element located in an outer side of a disk from the read element. The servo write control apparatus detects a plurality of first burst signals recorded in a circumferential direction of the disk by the read element. The servo write control apparatus calculates an offset in a radial direction when the write element writes a second burst signal, based on amplitude values of at least two of the first burst signals used for positioning the read element. The servo write control apparatus adjusts a write position of the second burst signal based on the offset.
    Type: Grant
    Filed: March 10, 2016
    Date of Patent: May 28, 2019
    Assignee: Kabushiki Kaisha Toshiba
    Inventors: Shigen Yasunaka, Shinji Takakura
  • Patent number: 10304491
    Abstract: Operations include compensating for a Tracking Error Signal (TES) offset in an optical tape drive. The tracking error offset compensation system detects a control signal for controlling movement of an optical head across a surface of a tape. The tracking error offset compensation system computes an estimated movement of the optical head, based on the initial control signal. The tracking error offset compensation system determines an estimated TES offset, based on the estimated movement of the optical head. The tracking error offset compensation system uses the estimated TES offset to correct a TES. The tracking error offset compensation system transmits the corrected TES, for controlling additional movement of the optical head.
    Type: Grant
    Filed: March 29, 2018
    Date of Patent: May 28, 2019
    Assignee: Oracle International Corporation
    Inventors: Scott David Wilson, Hua Zhong
  • Patent number: 10276197
    Abstract: An apparatus may include a first and second servo channels configured to output first and second position information to first and second writers, respectively, via a shared write path such that the first and second writers write first and second position information to first and second magnetic recording medium surfaces, respectively. In addition, the apparatus may include a controller configured to control the shared write path such that write access is changed between the first servo channel and second servo channel a plurality of times during a revolution of the first magnetic recording medium surface and second magnetic recording medium surface.
    Type: Grant
    Filed: October 25, 2017
    Date of Patent: April 30, 2019
    Assignee: Seagate Technology LLC
    Inventors: Jason Bellorado, Marcus Marrow
  • Patent number: 10268553
    Abstract: Method and apparatus for predicting data storage device failures using adaptive failure prediction modeling. In some embodiments, monitored parameters are used to predict a potential imminent failure of a first data storage device using a first copy of a first failure prediction model (FPM). Data associated with the predicted potential imminent failure are transferred by the device across a computer network to a host device. The host device generates an updated, second FPM responsive to the transferred data as well as from data from at least a second data storage device transmitted across the computer network having a second copy of the first FPM. A first copy of the updated, second FPM is transferred, via the network, for use by the second data storage device.
    Type: Grant
    Filed: August 31, 2016
    Date of Patent: April 23, 2019
    Assignee: Seagate Technology LLC
    Inventors: Nicholas Scott Eggert, Wenjuan Wang, Sailaja Venkata Chilaka, Satya V. Allumallu, Jason M. Feist, Bruce D. Emo
  • Patent number: 10255942
    Abstract: A tape transport control system with enhanced regulation of tape tension and velocity over the entire length of the tape. For example, a closed-loop control system for controlling a tape transport includes circuitry adapted to output a signal representing a tape velocity at a tape head, circuitry adapted to output a signal representing a tape velocity at the first tape reel and a signal representing a tape velocity at the second tape reel, circuitry adapted to output a signal representing a tape tension, and circuitry adapted to, based on the received signals, generate control signals to control the tape velocity at least at one of the tape head, the first tape reel, the second tape reel, and the tension of the tape, using controller gains that depend on a longitudinal position of the tape, and to implement a system transfer function that is approximately independent of the longitudinal position.
    Type: Grant
    Filed: August 23, 2016
    Date of Patent: April 9, 2019
    Assignee: International Business Machines Corporation
    Inventors: Giovanni Cherubini, Mark A. Lantz, Angeliki Pantazi
  • Patent number: 10242704
    Abstract: A plurality of commands is received from a host to perform at least one of reading data and writing data on a magnetic storage media of a Data Storage Device (DSD). The plurality of commands is clustered for performance based at least in part on a timing control of a fly-height heater of the DSD that is configured to adjust a flying height of a head of the DSD while the head is flying over the magnetic storage media. A cluster of commands is performed including the plurality of commands by controlling the head to perform at least one of reading and writing data on the magnetic storage media for the cluster of commands.
    Type: Grant
    Filed: June 21, 2018
    Date of Patent: March 26, 2019
    Assignee: Western Digital Technologies, Inc.
    Inventors: Haibao Zhao, Bernhard Hiller, Francis Crimi
  • Patent number: 10236021
    Abstract: A magnetic recording apparatus includes a magnetic recording medium; a magnetic recording head including a first magnetic pole part, a second magnetic pole part, and a magnetic flux control part provided between the first magnetic pole part and the second magnetic pole part, wherein the magnetic flux control part includes a first layer provided between the first magnetic pole part and the second magnetic pole part, a second layer provided between the first magnetic pole part and the first layer, and a third layer provided between the second magnetic pole part and the first layer; an electrode for applying a current to the magnetic flux control part; and an electric circuit for energizing the current to the electrode, wherein an oscillation frequency of magnetization of the magnetic layer is greater than a ferromagnetic resonance frequency of the magnetic recording medium.
    Type: Grant
    Filed: August 28, 2017
    Date of Patent: March 19, 2019
    Assignee: Kabushiki Kaisha Toshiba
    Inventors: Naoyuki Narita, Masayuki Takagishi, Kenichiro Yamada, Tomoyuki Maeda, Akihiko Takeo
  • Patent number: 10229707
    Abstract: A disk device includes first and second recording surfaces, a first head for the first recording surface, including a first heater which generates heat via a first electric power, a second head for the second recording surface, including a second heater which generates heat via a second electric power, and a control circuit configured to execute a first preheating operation in which the first electric power is supplied to the first heater for a first time interval prior to starting a first writing process to write data on the first recording surface by the first head, and to execute a second preheating operation in which the second electric power is supplied to the second heater for a second time interval prior to starting a second writing process to write data on the second recording surface by the second head. The first time interval is different from the second time interval.
    Type: Grant
    Filed: September 3, 2017
    Date of Patent: March 12, 2019
    Assignee: KABUSHIKI KAISHA TOSHIBA
    Inventor: Koji Ishii
  • Patent number: 10225119
    Abstract: Systems and techniques for communicating data as a function of frequency are presented. In an implementation, a system includes a microelectromechanical systems (MEMS) sensor, a digital signal processor and a frequency detection circuit. The digital signal processor is coupled to the MEMS sensor. The frequency detection circuit receives data encoded as a function of frequency from the digital signal processor via a clock communication channel.
    Type: Grant
    Filed: July 9, 2015
    Date of Patent: March 5, 2019
    Assignee: INVENSENSE, INC.
    Inventors: Yuanjin Li, Yang Pan, Jia Zhao, Dan Li, Hao Ding
  • Patent number: 10192570
    Abstract: A magnetic disk device includes a disk, a head configured to write data on the disk, and a controller. The controller generates a target trajectory of the head in a circumferential direction for writing to a plurality of sectors in a current track, wherein the target trajectory is based on an actual trajectory of the head for writing to a plurality of sectors in a previously written track that is adjacent to the current track, determines that the previously written track is discontinuous between an initial sector of the previously written track and an end sector of the previously written track by a radial offset, generates a corrected trajectory for writing the plurality of sectors in the current track, and controls a position of the head in a radial direction based on the corrected trajectory while writing to the plurality of sectors in the current track.
    Type: Grant
    Filed: September 3, 2017
    Date of Patent: January 29, 2019
    Assignee: Kabushiki Kaisha Toshiba
    Inventors: Takayuki Kawabe, Takeyori Hara
  • Patent number: 10186293
    Abstract: The magnetic tape device includes a magnetic tape including a magnetic layer, in which an intensity ratio of a peak intensity of a diffraction peak of a (110) plane with respect to a peak intensity of a diffraction peak of a (114) plane of a hexagonal ferrite crystal structure obtained by an X-ray diffraction analysis of the magnetic layer by using an In-Plane method is 0.5 to 4.0, a vertical direction squareness ratio of the magnetic tape is 0.65 to 1.00, Ra measured regarding a surface of the magnetic layer is equal to or smaller than 2.0 nm, and a C—H derived C concentration calculated from a C—H peak area ratio of C1s spectra obtained by X-ray photoelectron spectroscopic analysis performed on the surface of the magnetic layer at a photoelectron take-off angle of 10 degrees is 45 to 65 atom %.
    Type: Grant
    Filed: March 14, 2018
    Date of Patent: January 22, 2019
    Assignee: FUJIFILM Corporation
    Inventors: Norihito Kasada, Eiki Ozawa
  • Patent number: 10152995
    Abstract: The magnetic tape device includes a magnetic tape including a magnetic layer, in which an intensity ratio of a peak intensity of a diffraction peak of a (110) plane with respect to a peak intensity of a diffraction peak of a (114) plane of a hexagonal ferrite crystal structure obtained by an X-ray diffraction analysis of the magnetic layer by using an In-Plane method is 0.5 to 4.0, a vertical direction squareness ratio of the magnetic tape is 0.65 to 1.00, Ra measured regarding a surface of the magnetic layer is equal to or smaller than 2.0 nm, and a C—H derived C concentration calculated from a C—H peak area ratio of C1s spectra obtained by X-ray photoelectron spectroscopic analysis performed on the surface of the magnetic layer at a photoelectron take-off angle of 10 degrees is 45 to 65 atom %.
    Type: Grant
    Filed: March 14, 2018
    Date of Patent: December 11, 2018
    Assignee: FUJIFILM Corporation
    Inventors: Norihito Kasada, Eiki Ozawa
  • Patent number: 10134431
    Abstract: A microactuator for a suspension is described. The microactuator includes a multi-layer PZT device having a first face and an opposite second face. Each layer of the multi-layer PZT device is configured to operate in its d15 mode when actuated by an actuation voltage. The layers are configured as a stack such that each layer is configured to act in the same direction when actuated such that the first face moves in shear relative to the second face.
    Type: Grant
    Filed: April 25, 2017
    Date of Patent: November 20, 2018
    Assignee: Magnecomp Corporation
    Inventor: Kuen Chee Ee
  • Patent number: 10108152
    Abstract: A servo control device according to the present invention includes a speed command generation unit, a torque command generation unit, a speed detection unit, a speed control loop, a speed control gain setting unit for setting a speed control gain for the speed control loop, a sinusoidal disturbance input unit for performing a sinusoidal sweep on the speed control loop, a frequency characteristic calculation unit, and a gain adjustment unit. When the speed control loop has fallen into an oscillation state and has become unstable owing to the increased speed control gain, the speed control gain is reduced and the sinusoidal sweep is temporarily stopped. After the speed control loop is stabilized using the speed control gain which is lower than in the unstable state, the sinusoidal sweep is restarted.
    Type: Grant
    Filed: March 23, 2017
    Date of Patent: October 23, 2018
    Assignee: FANUC CORPORATION
    Inventor: Kazunori Iijima
  • Patent number: 10074390
    Abstract: A PZT microactuator such as for a hard disk drive has a restraining layer bonded on its side that is opposite the side on which the PZT is mounted. The restraining layer comprises a stiff and resilient material such as stainless steel. The restraining layer can cover most or all of the top of the PZT, with an electrical connection being made to the PZT where it is not covered by the restraining layer. The restraining layer reduces bending of the PZT as mounted and hence increases effective stroke length, or reverses the sign of the bending which increases the effective stroke length of the PZT even further. The restraining layer can be one or more active layers of PZT material that act in the opposite direction as the main PZT layer. The restraining layer(s) may be thinner than the main PZT layer.
    Type: Grant
    Filed: February 29, 2016
    Date of Patent: September 11, 2018
    Assignee: Magnecomp Corporation
    Inventors: Peter Hahn, Kuen Chee Ee, Long Zhang
  • Patent number: 10074391
    Abstract: A hard disk drive (HDD) is configured to move a read head over a region of a storage surface that includes unreadable segments of reference spirals that have been overwritten by a reference spiral in a set of spirals that is currently being written on the storage surface. By moving the read head across the region of the storage surface at a return radial velocity that is selected such that the write head crosses no consecutive reference spirals at an unreadable segment, the servo system of the HDD does not experience an error due to crossing multiple consecutive reference spirals at unreadable segments. Thus, a set of spirals that includes partially damaged reference spirals can be employed to control the position of a read head. Consequently, a second surface is not required for the set of spirals employed in controlling the writing process.
    Type: Grant
    Filed: March 8, 2017
    Date of Patent: September 11, 2018
    Assignee: Kabushiki Kaisha Toshiba
    Inventors: Zhi Wang, Jiangang Liang
  • Patent number: 10074392
    Abstract: During in-drive writing of a servo spiral on a disk surface, a servo spiral can be distinguished during demodulation from adjacent servo spirals on the same disk surface. When a set of servo spirals is written on a disk surface, a first spiral is written to include a first identifying characteristic and the following spiral is written to include a second identifying characteristic. The identifying characteristic may include embedded sync marks encoding a certain numerical value, a unique frequency of high-low transitions included in each spiral, and/or a unique frame size.
    Type: Grant
    Filed: March 9, 2017
    Date of Patent: September 11, 2018
    Assignee: Kabushiki Kaisha Toshiba
    Inventor: Anton Gerasimov
  • Patent number: 10056099
    Abstract: Various embodiments for error recovery in a data storage environment, by a processor device, are provided. For monitoring signal from one or more read channels in a tape storage drive, a variable range of offsets organized by row into a table is selected by a microcode algorithm and applied by a track following servo mechanism of the tape storage drive to position a read head in relation to a track of a tape media at an offset up to and including beyond a predetermined margin of the track.
    Type: Grant
    Filed: February 21, 2017
    Date of Patent: August 21, 2018
    Assignee: INTERNATIONAL BUSINESS MACHINES CORPORATION
    Inventor: Pamela R. Nylander-Hill
  • Patent number: 10056107
    Abstract: A control device is provided which can perform a retraction operation of a head included in a disk storage device with lower power consumption. The control device of the disk storage device includes a control unit that controls a motor and retracts the head from over a disk to a ramp mechanism when power supply is shut down, an acquisition unit that acquires information related to a moving distance of the head that retracts to the ramp mechanism, and a calculation unit that calculates the moving distance of the head based on the information acquired by the acquisition unit. The control unit switches an operation of the motor from a first retract operation to a second retract operation when determining that the head reaches a first position after passing through an inclined surface of the ramp mechanism based on the moving distance calculated by the calculation unit.
    Type: Grant
    Filed: September 27, 2017
    Date of Patent: August 21, 2018
    Assignee: Renesas Electronics Corporation
    Inventors: Minoru Kurosawa, Kichiya Itagaki, Seigi Ishiji
  • Patent number: 10049692
    Abstract: Gain values used by a variable gain amplifier (VGA) to read servo marks of a heat-assisted recording medium are measured. Sector-specific, repeatable gain values that indicate an expected VGA gain at a desired clearance are determined based on the measured gain values. The sector-specific, repeatable gain values are used as input to a closed-loop clearance controller together with measured values of servo VGA gain while writing data to the recording medium.
    Type: Grant
    Filed: October 28, 2015
    Date of Patent: August 14, 2018
    Assignee: Seagate Technology LLC
    Inventors: Xiong Liu, Lihong Zhang, KianKeong Ooi, Xiang Lu
  • Patent number: 10032467
    Abstract: The presently disclosed technology teaches integrating disc drive electronics into a transducer head. Decreased electrical transit times and data processing times can be achieved by placing the electronics on or within the transducer head because electrical connections may be made physically shorter than in conventional systems. The electronics may include one or more of a control system circuit, a write driver, and/or a data buffer. The control system circuit generates a modified clock signal that has a fixed relation to phase and frequency of a bit-detected reference signal that corresponds to positions of patterned bits on the disc. The write driver writes outgoing data bits received from an external connection to off-head electronics directly to the writer synchronized with the modified clock signal. The data buffer stores and converts digital data bits sent from the off-head electronics to an analog signal that is synchronized with the modified clock signal.
    Type: Grant
    Filed: November 30, 2017
    Date of Patent: July 24, 2018
    Assignee: SEAGATE TECHNOLOGY LLC
    Inventors: Mark Anthony Gubbins, Robert William Lamberton, Robert Edward Weinstein, James Joseph Touchton
  • Patent number: 10014027
    Abstract: Apparatus and method contemplating an in-situ test method for a head gimbal assembly (HGA). The method includes individually exciting a pair of opposing-effect microactuators supporting the read/write head adjacent a data storage media; summing the outputs from the microactuators to derive a spectral frequency response of the HGA; determining a resonant frequency from the spectral frequency response; driving the microactuators at the resonant frequency; and varying the read/write fly height apart from the data storage media to correlate contact with a maximum response of the microactuators.
    Type: Grant
    Filed: September 1, 2017
    Date of Patent: July 3, 2018
    Assignee: Seagate Technology LLC
    Inventors: Vijay Kumar, Narayanan Ramakrishnan
  • Patent number: 10008227
    Abstract: According to one embodiment, a magnetic disk apparatus includes a magnetic head, a voice coil motor, a driving circuit, and a VCM resistance estimation unit. The magnetic head accesses a magnetic disk. The voice coil motor drives the magnetic head over the magnetic disk. The driving circuit applies a VCM current to the voice coil motor. The VCM resistance estimation unit estimates a VCM resistance in the voice coil motor based on the saturated VCM current and a velocity of the magnetic head.
    Type: Grant
    Filed: August 3, 2017
    Date of Patent: June 26, 2018
    Assignee: Kabushiki Kaisha Toshiba
    Inventors: Daisuke Sudo, Takeyori Hara
  • Patent number: 10008229
    Abstract: A method, apparatus, and system are provided for implementing track following using signal asymmetry metrics monitored during read back in hard disk drives (HDDs). Signal asymmetry metrics monitored during read back are used together with a position error signal (PES) to correct and guide the position of a read sensor with respect to a written track in the HDD.
    Type: Grant
    Filed: January 5, 2016
    Date of Patent: June 26, 2018
    Assignee: WESTERN DIGITAL TECHNOLOGIES, INC
    Inventors: Richard Leo Galbraith, Weldon Mark Hanson, Mark A. Nichols, Alexander Taratorin, Roger William Wood
  • Patent number: 10002631
    Abstract: An apparatus comprising a slider and a detector coupled to the slider. The slider is configured for writing data to and reading data from a magnetic recording medium. The slider comprises a heater configured to receive a modulated signal and cause oscillation in a spacing between the slider and the medium. At least one heat generating component of the slider is configured to receive a modulated signal. A contact sensor is situated on the slider to receive heat generated by the at least one heat generating component. The detector is configured to measure a response signal of the heated contact sensor as the slider approaches the medium. The detector is further configured to detect contact between the slider and the medium in response to the response signal reaching a predetermined threshold.
    Type: Grant
    Filed: June 23, 2017
    Date of Patent: June 19, 2018
    Assignee: Seagate Technology LLC
    Inventors: James Dillon Kiely, Zhen Wei, Neil Zuckerman, John Charles Duda, Eric L. Montei
  • Patent number: 9990950
    Abstract: An apparatus comprises a slider configured for heat-assisted magnetic coupled to a controller. The slider comprises a writer, a heater, a near-field transducer, and an optical waveguide for communicating light from a laser diode to the near-field transducer. The controller is configured to set a target pre-write clearance of the slider prior to performing a write operation, set a target write clearance of the slider for performing the write operation, and determine a difference between the target pre-write and write clearances to define a target pre-write clearance offset. The controller is also configured to measure, for a plurality of different target pre-write clearance offsets, a writability metric for the slider while sweeping a laser diode current, and adjust the target pre-write clearance offset so that the writability metric reaches a predetermined threshold. The controller is further configured to perform subsequent write operations using the adjusted target pre-write clearance offset.
    Type: Grant
    Filed: July 17, 2017
    Date of Patent: June 5, 2018
    Assignee: Seagate Technology LLC
    Inventors: Drew Michael Mader, Steven J. Kimble, Jason W. Riddering
  • Patent number: 9959898
    Abstract: A magnetic disk device includes a magnetic disk having a plurality of tracks, a magnetic head used for writing data on the magnetic disk and reading data from the magnetic disk, a controller configured to control seek operations of the magnetic head, and a vibration sensor. The controller predicts a first vibration caused by a currently executed seek operation, based on a seek control signal, predicts a second vibration based on vibration detected by the sensor, and determines an adjusted start time of the currently executed seek operation so that a phase of the first vibration does not match a phase of the second vibration.
    Type: Grant
    Filed: September 3, 2017
    Date of Patent: May 1, 2018
    Assignee: KABUSHIKI KAISHA TOSHIBA
    Inventors: Shihpo Hsu, Takeyori Hara
  • Patent number: 9947356
    Abstract: A method of writing servo spirals for spiral-based self-servo writing includes determining control parameters for controlling movement of a write head between a first and a second disk radial location at a first velocity, writing a first spiral while controlling the movement of the write head between the first and the second disk radial location at the first velocity according to the determined control parameters, writing a second spiral while controlling movement of the write head between the first and the second disk radial location at a second velocity that is different from the first velocity, based on timing and location information from the first spiral, and writing a third spiral while controlling movement of the write head between the first and the second disk radial location at the first velocity according to the determined control parameters and based on timing and location information from the second spiral.
    Type: Grant
    Filed: March 9, 2017
    Date of Patent: April 17, 2018
    Assignee: Kabushiki Kaisha Toshiba
    Inventors: Richard Oswald, Gabor Szita, Li Zhang
  • Patent number: 9947350
    Abstract: A driver device coupled to a winding of an electro-mechanical actuator includes: a power stage driving the winding in a discontinuous mode by alternating conduction on-phases to off-phases, and a sensor circuit sensing a voltage across the winding in an off-phase, wherein, during such an off-phase the voltage across the winding includes a residual voltage which decays to zero. The power stage drives the winding from an on-phase to an off-phase by applying to the winding a reverse current pulse to invert the direction of flow of the current through the winding and produce an oscillation of the residual voltage, whereby the residual voltage includes a zero-crossing point after the current through the winding is exhausted. The sensor circuit senses the voltage across the winding at this zero-crossing point, whereby the voltage sensed across the winding at the zero-crossing point is indicative of the back electromotive force of the winding.
    Type: Grant
    Filed: June 28, 2017
    Date of Patent: April 17, 2018
    Assignee: STMICROELECTRONICS S.R.L.
    Inventors: Michele Boscolo Berto, Ezio Galbiati, Giuseppe Maiocchi
  • Patent number: 9948226
    Abstract: An apparatus for driving a voice coil actuator of a camera and a method thereof are provided. The driving apparatus performs input shaping based on a resonance frequency of a voice coil actuator and damping of vibration in the voice coil actuator to generate a control signal using a shaping signal as an initial input from an unshaped control signal, and thereby drives the voice coil actuator using the control signal subjected to input shaping. The shaping signal is provided to remove the resonance of the voice coil actuator, and may be a pure shaping signal, such as a multi-step shaping signal or a toggle shaping signal, or a convoluted shaping signal obtained by convoluting such pure shaping signals. The driving apparatus may significantly reduce residual vibration and may enhance an auto-focus function of the voice actuator using input shaping control based on damping.
    Type: Grant
    Filed: April 21, 2016
    Date of Patent: April 17, 2018
    Assignee: DONG WOON ANATECH CO., LTD.
    Inventors: Young Hoon Kim, Min Ho Yun, Jin Park, Ho Jun Lee
  • Patent number: 9947352
    Abstract: According to one embodiment, a VCM resistance estimation unit estimates a VCM resistance in a voice coil motor based on an acceleration and a velocity of a magnetic head with a VCM voltage saturated, and an equivalent current force constant estimation unit estimates an equivalent current force constant of the voice coil motor based on the acceleration and the velocity of the magnetic head with the VCM voltage saturated.
    Type: Grant
    Filed: August 4, 2017
    Date of Patent: April 17, 2018
    Assignee: Kabushiki Kaisha Toshiba
    Inventors: Daisuke Sudo, Takeyori Hara
  • Patent number: 9947357
    Abstract: A read/write head has a set of components that at least include: at least one clearance actuator; at least one read transducer configured to read from a magnetic recording medium; and at least one write transducer configured to write to the magnetic recording medium. A switch network is coupled to the set of components and configured to, in response to a control signal, couple a selected sub-combination of the components to a common set of signal lines. The coupling of the selected sub-combination facilitates operation in a selected mode of the read/write head.
    Type: Grant
    Filed: March 31, 2016
    Date of Patent: April 17, 2018
    Assignee: SEAGATE TECHNOLOGY LLC
    Inventors: Tim Rausch, Jon D. Trantham, Jason Bryce Gadbois
  • Patent number: 9940967
    Abstract: A data storage device is disclosed comprising a first disk surface comprising a plurality of servo tracks, a first head actuated over the first disk surface, wherein the first head comprises a first read element, and a second read element. During a write operation first servo data in a first servo track is read using the first read element to generate a first read signal, and the first head is servoed over the first servo track based on the first read signal while writing data to the first disk surface. Second servo data is read using the second read element to generate a second read signal, and the write operation is aborted when the first read signal indicates a shock event is affecting the servoing of the first head and the second read signal confirms the shock event.
    Type: Grant
    Filed: August 29, 2017
    Date of Patent: April 10, 2018
    Assignee: Western Digital Technologies, Inc.
    Inventors: James B. French, Jr., Gary A. Herbst
  • Patent number: 9934806
    Abstract: Provided herein is a method, including creating a first pattern in a data region of a substrate, and creating a second pattern in a servo region of a substrate. A circumferential line pattern is created overlapping the first pattern to create rectangle-shaped protrusions in the data region of the substrate. A chevron pattern is created overlapping the second pattern to create chevron-derived protrusions in the servo region of the substrate.
    Type: Grant
    Filed: January 10, 2017
    Date of Patent: April 3, 2018
    Assignee: Seagate Technology LLC
    Inventors: Shuaigang Xiao, David S. Kuo, XiaoMin Yang, Kim Y. Lee, Yautzong Hsu, Koichi Wago
  • Patent number: 9911448
    Abstract: A perpendicular magnetic recording medium according to an embodiment includes a substrate and perpendicular magnetic recording layer. The perpendicular magnetic recording layer includes a recording portion and non-recording portion. The recording portion has patterns regularly arranged in the longitudinal direction, and includes magnetic layers containing Fe or Co and Pt as main components, and at least one additive component selected from Ti, Si, Al, and W. The non-recording portion includes oxide layers formed by oxidizing the side surfaces of the magnetic layers, and nonmagnetic layers formed between the oxide layers.
    Type: Grant
    Filed: March 15, 2016
    Date of Patent: March 6, 2018
    Assignee: KABUSHIKI KAISHA TOSHIBA
    Inventors: Takeshi Iwasaki, Kazutaka Takizawa, Akira Watanabe, Kaori Kimura, Akihiko Takeo
  • Patent number: 9881644
    Abstract: The invention generally relates to a hard disk drive with a disk, a read/write head, a z-axis actuator, and a controller. A surface of the disk and/or the head can be bare and thus devoid of any overcoat or lubricant layer, or alternatively the disk surface can have one or more layers with a combined thickness of less than 4 nanometers and the head can have a layer with a thickness of less than 2 nanometers. The hard disk drive can be enclosed, and its enclosed space can be a low pressure environment such as a near-zero or a zero pressure environment.
    Type: Grant
    Filed: June 13, 2017
    Date of Patent: January 30, 2018
    Assignee: L2 Drive Inc.
    Inventor: Karim Kaddeche
  • Patent number: 9865292
    Abstract: A slider having an air bearing surface is configured for heat-assisted magnetic recording. A writer of the slider comprises a writer coil. A current source is configured to supply a modulated writer current at a first predetermined frequency to the writer coil. A writer heater is situated proximate the writer and configured to thermally actuate a writer region of the air bearing surface. A contact sensor is situated proximate the writer coil and configured to sense temperature changes indicative of changes in spacing and contact between the slider and a magnetic recording medium. A signal produced by the contact sensor oscillates at the first predetermined frequency. A detector is coupled to the contact sensor. The detector is configured to detect contact between the thermally actuated writer region and the medium using the contact sensor signal.
    Type: Grant
    Filed: February 28, 2017
    Date of Patent: January 9, 2018
    Assignee: SEAGATE TECHNOLOGY LLC
    Inventors: James Dillon Kiely, Neil Zuckerman
  • Patent number: 9818439
    Abstract: A change in servo active gain control values is determined from a beginning of a writing of a test region of a recording medium to an end of the writing of the test region. The servo active gain control values are read from servo marks by a read transducer of a read/write head during the writing. After writing of the test region, the test region is read by the read transducer to determine a change in recorded amplitude from the beginning of the writing to the end of the writing. A gamma value of the read/write head is determined based on the change in servo active gain control values and the change in recorded amplitude.
    Type: Grant
    Filed: March 18, 2016
    Date of Patent: November 14, 2017
    Assignee: SEAGATE TECHNOLOGY LLC
    Inventors: Jason Riddering, Huazhou Lou
  • Patent number: 9805759
    Abstract: An adjusting method for a magnetic disk device including a disk, a head that writes data on the disk, a controller circuit that outputs write data and a control signal related to the write data, and an integrated circuit that outputs a write current to the head, includes adding a delay to a timing of polarity inversion of one bit of the write data or the control signal, outputting the write data and the control signal added with the delay from the controller circuit to the integrated circuit, outputting from the integrated circuit to the head, the write current having a current value that is changed at one of timings of polarity inversion of the write data, according to the control signal, and adjusting a deviation between the write data and the control signal, based on the output write current.
    Type: Grant
    Filed: March 3, 2017
    Date of Patent: October 31, 2017
    Assignee: KABUSHIKI KAISHA TOSHIBA
    Inventor: Keiichi Kishino
  • Patent number: 9804922
    Abstract: Systems and methods for partial bad block reuse may be provided. Data may be copied from a block of a first memory to a block of a second memory. A post write read error may be detected in a first portion the data copied to the block of the second memory without detection of a post write read error in a second portion of the data copied to the block of the second memory. The block of the second memory may be determined to be a partial bad block usable for storage in response to detection of the post write read error in the first portion of the data but not in the second portion of the data.
    Type: Grant
    Filed: July 21, 2014
    Date of Patent: October 31, 2017
    Assignee: SanDisk Technologies LLC
    Inventors: Mrinal Kochar, Abhijeet Bhalerao, Derek McAuley, Piyush Sagdeo
  • Patent number: 9801299
    Abstract: A server disk drive holder assembly includes an outer tray, an inner tray and a latch arm. The outer tray includes a locking hole. The inner tray overlaps on the outer tray. The inner tray is movable with respect to the outer tray. The inner tray includes a fastening hole. A latch arm is pivotally disposed on an outer side of the outer tray. The latch arm includes a hook portion. When the locking hole is aligned with the fastening hole, the hook portion is inserted through the locking hole to be engaged with the fastening hole. A disk drive can be clamped between the outer tray and the inner tray. By utilizing the movable latch arm to fasten the outer tray and the inner tray, the disk drive can be quickly mounted and dismounted.
    Type: Grant
    Filed: October 1, 2016
    Date of Patent: October 24, 2017
    Assignee: SUPER MICRO COMPUTER INC.
    Inventors: Richard S. Chen, Lawrence H. Liang, Jerry C. Yang
  • Patent number: 9792940
    Abstract: Using a high sample rate dPES, together with pulsed heater and lock-in technique, to improve dPES SNR for contact detection between the head and media surface. Steps of powering a transducing head actuator with pulsed input signal at a select data track offset from a previously-written to data track of the storage medium, where the pulsed input signal has select amplitude and duty cycle to simulate a response signal, and further locking in an amplitude with respect to the heater frequency, can lead to a determination of level of heater power for initiating contact between the transducing head and the storage medium.
    Type: Grant
    Filed: March 15, 2013
    Date of Patent: October 17, 2017
    Assignee: Seagate Technology LLC
    Inventors: Lin Zhou, Juil Lee, Dongming Liu, Huazhou Lou
  • Patent number: 9792054
    Abstract: Methods and apparatuses for optimizing the performance of a storage system comprise a FLASH storage system, a hard drive storage system, and a storage controller. The storage controller is adapted to receive READ and WRITE requests from an external host, and is coupled to the FLASH storage system and the hard drive storage system. The storage controller receives a WRITE request from an external host containing data and an address, forwards the received WRITE request to the FLASH storage system and associates the address provided in the WRITE request with a selected alternative address, and provides an alternative WRITE request, including the selected alternative address and the data received in the WRITE request, to the hard drive storage system, wherein the alternative address is selected to promote sequential WRITE operations within the hard drive storage system.
    Type: Grant
    Filed: March 21, 2016
    Date of Patent: October 17, 2017
    Assignee: International Business Machines Corporation
    Inventors: Holloway H. Frost, Daniel E. Scheel
  • Patent number: 9786309
    Abstract: A data storage device is disclosed comprising a head actuated over a disk, wherein the head comprises a fly height actuator (FHA). A FHA control signal is applied to the FHA, wherein the FHA control signal comprises a DC component and an AC component. A fly height metric is measured representing a fly height of the head over the disk for different levels of the DC component. A modulation amplitude of the fly height metric is detected, and a minimum in the modulation amplitude of the fly height metric is detected.
    Type: Grant
    Filed: June 6, 2017
    Date of Patent: October 10, 2017
    Assignee: Western Digital Technologies, Inc.
    Inventors: Bernhard E. Knigge, Noureddine Kermiche, Robert E. Eaton, Puneet Bhargava
  • Patent number: 9766677
    Abstract: Some embodiments involve a method of managing power for a first multiple-data-storage-devices enclosure. The method can include: checking out a first token over a network connection from a token pool shared by multiple-data-storage-devices enclosures including the first enclosure, wherein each token of the token pool is available to be checked out by a single device and wherein the enclosures share power drawn from a power supply; after checking out the first token, initiating activation of a data storage device within the first enclosure; monitoring power consumption within the first enclosure; and releasing the first token back to the token pool when the power consumption in the first enclosure substantially reaches a steady-state after the activation of the data storage device is initiated.
    Type: Grant
    Filed: May 13, 2014
    Date of Patent: September 19, 2017
    Assignee: NetApp, Inc.
    Inventor: David Slik