Dynamic Information Element Testing Patents (Class 324/212)
  • Patent number: 11355143
    Abstract: Described are magnetic recording heads that include an air-bearing surface and that are designed to be useful or potentially useful in two or more different types of fluid atmospheres; also described are related methods of testing the magnetic recording heads and installing the magnetic recording heads in a hard disk drive, as well as hard disk drives that contain a magnetic recording head as described.
    Type: Grant
    Filed: June 8, 2020
    Date of Patent: June 7, 2022
    Assignee: Seagate Technology LLC
    Inventors: Jiaxi Lu, Matthew Aaron Carper, Abhik Rakshit
  • Patent number: 10468063
    Abstract: Methods and systems for detecting hidden sectors in a hard drive. The method may include initiating a linear copy of the hard drive and, while the hard drive is being copied, capturing images of a platter and an actuator arm within the hard drive using an imaging device. The captured images are output and they indicate a range of movement of the actuator arm across the platter during the linear copy. Ranges of movement that fail to scan across the full expected size of the platter may be indicative of a modified partition record that maliciously hides a portion of the hard drive from the copy operation.
    Type: Grant
    Filed: December 21, 2018
    Date of Patent: November 5, 2019
    Assignee: BlackBerry Limited
    Inventor: Adam John Boulton
  • Patent number: 10395690
    Abstract: A magnetic disk device includes a disk, a head configured to write data on the disk based on a write current, and a controller configured to determine whether a write error occurs when data is written on the disk, based on a change in a heating value of the head, and upon determining that the write error occurs, read the data written on the disk.
    Type: Grant
    Filed: February 28, 2018
    Date of Patent: August 27, 2019
    Assignees: KABUSHIKI KAISHA TOSHIBA, TOSHIBA ELECTRONIC DEVICES & STORAGE CORPORATION
    Inventor: Tomokazu Okubo
  • Patent number: 10387232
    Abstract: An image forming apparatus includes an HDD, an HDD confirming unit, a system control unit, and a non-volatile semiconductor storage device. The HDD confirming unit detects a failure of the HDD and, in situations where a failure is detected, executes a confirmation process of detecting any operable portion of the HDD. The non-volatile semiconductor storage device stores system data used for operation of the system control unit. In a failure of the HDD, when the HDD confirming unit does not detect any operable portion, the system control unit separates the HDD from the image forming apparatus and sets the image forming apparatus into a restriction mode. In a failure of the HDD, when the HDD confirming unit detects an operable portion, the system control unit does not separate the HDD from the image forming apparatus and sets the image forming apparatus into a small-capacity mode.
    Type: Grant
    Filed: March 27, 2017
    Date of Patent: August 20, 2019
    Assignee: Kyocera Document Solutions Inc.
    Inventor: Masahiro Suzuki
  • Patent number: 10134624
    Abstract: Apparatus and method for aligning a rotatable substrate to a support mechanism to write a feature to the substrate, and a substrate so configured. In some embodiments, the substrate has a circumferentially extending timing pattern with spaced apart first and second timing marks disposed on opposing sides of a center point of the timing pattern and an identification (ID) field that stores a unique identifier value associated with the substrate. Upon mounting of the substrate to a support mechanism that rotates the substrate about a central axis that is offset from the center point, a control circuit generates a compensation value to compensate for the offset using the first and second timing marks and outputs a process instruction to authorize processing of the substrate using the unique identifier value. In some cases, the unique identifier value is used as a lookup to a computerized database.
    Type: Grant
    Filed: March 9, 2018
    Date of Patent: November 20, 2018
    Assignee: Doug Carson & Associates, Inc.
    Inventors: Douglas M. Carson, Mike Chatterton, Stephen Houser, Bryan Whitfield
  • Patent number: 10115420
    Abstract: A unitary cartridge, or module, provides a self-contained, high accuracy, ready-to-use assembly for controlling fine positioning of a head gimbal assembly (HGA) disposed on a head mounting unit mounted on the cartridge, with respect to a spinstand or other device associated with a head tester. In a form, the head-mounting unit and a counterweight element are configured to be moveable relative to the base in opposite directions along a displacement axis in response to actuators in the cartridge, and are operative in concert with a damping assembly configured to interact with the counterweight element and the heads mounting unit to mitigate vibrational movement of the cartridge.
    Type: Grant
    Filed: March 25, 2016
    Date of Patent: October 30, 2018
    Assignee: Guzik Technical Enterprises
    Inventors: Nahum Guzik, Konstantin Perevoztchikov, Wei Zhuang
  • Patent number: 9995596
    Abstract: An apparatus includes a circuit, a code modulator, and an actuator. The circuit is operable to detect displacements of a rotating object while in motion. The circuit is operable to detect a position of the displacements and to generate a signal associated therewith. The code modulator is operable to generate a modulated signal based on the position and the displacements. The actuator is operable to apply a force to the rotating object, wherein the force is based on the modulated signal.
    Type: Grant
    Filed: March 22, 2016
    Date of Patent: June 12, 2018
    Assignee: Seagate Technology LLC
    Inventor: Hans Leuthold
  • Patent number: 9953806
    Abstract: Apparatus and method for aligning a rotatable substrate to a support mechanism such as a turntable. The substrate has a circumferentially extending timing pattern comprising at least spaced apart first and second timing marks disposed on opposing sides of a center point of the substrate. The substrate is configured to be mounted to and rotated by the support mechanism about a central axis. The center point of the substrate may be offset from the central axis by an offset distance due to mechanical tolerances associated with the substrate mounting operation. The offset distance may be determined through successive detection of the first and second timing marks by a detector over at least one rotation of the support mechanism and the substrate. A write beam may be adjusted using the determined offset distance to write a second feature to the substrate in alignment with a previously written first feature.
    Type: Grant
    Filed: March 27, 2017
    Date of Patent: April 24, 2018
    Assignee: Doug Carson & Associates, Inc.
    Inventors: Douglas M. Carson, Mike Chatterton, Stephen Houser, Bryan Whitfield
  • Patent number: 9928881
    Abstract: A method of testing a dynamic write field of a recording head includes preparing a test magnetic medium and recording a write signal on the test magnetic medium with the write signal being set at a first write parameter and a second write parameter. An average of multiple read-back signals of the recorded write signal are captured to determine an average amplitude of the read-back signals. The recording of the write signal on the test magnetic medium and the capturing of the average of multiple read-back signals of the recorded write signal are repeated to determine the average amplitude of the read-back signals by fixing the first write parameter of the write signal and changing the second write parameter of the write signal until the average amplitude of the read-back signals saturates.
    Type: Grant
    Filed: September 21, 2017
    Date of Patent: March 27, 2018
    Assignee: Seagate Technology LLC
    Inventors: Zhe Shen, Zuxuan Lin, Lei Lu, Jianhua Xue
  • Patent number: 9841457
    Abstract: A test coupon includes a pseudo element circuit which is constituted of a main circuit section and an adjusting section. The main circuit section includes a first pattern conductor and second pattern conductors. The first pattern conductor and the second pattern conductors overlap one another with a dielectric layer interposed therebetween. The first pattern conductor electrically conducts to the second pattern conductors. The main circuit section represents the R-component and the L-component of an equivalent circuit, and is a dominant circuit element which determines a signal waveform. The adjusting section includes linear conductors. A peak of a voltage waveform is suppressed by the R- and L-components of the adjusting section.
    Type: Grant
    Filed: November 1, 2016
    Date of Patent: December 12, 2017
    Assignees: NHK SPRING CO., LTD., WESTERN DIGITAL TECHNOLOGIES, INC.
    Inventors: Futa Sasaki, Hajime Arai, Tomohisa Okada, Nobumasa Nishiyama, Kazuhiro Nagaoka
  • Patent number: 9702945
    Abstract: A magnetic measurement device which can measure the magnetic characteristics in a microregion of a thin plate magnetic sample. After a magnetic sample is applied by a magnetic field and magnetized accordingly, by scanning the magnetic sample using a measuring part, the magnetic flux leakage in the magnetic sample can be measured. The magnetic flux leaks outside by magnetizing a first region and a second region of the magnetic sample in reciprocally opposite directions and reducing the demagnetizing field. Specifically, a magnetic field generating part with at least a pair of magnetic poles is used to perform the magnetization of multiple poles, or the magnetic field generating part applies a damped oscillation magnetic field to perform the magnetization, or a local magnetic field generating part which applies an alternating magnetic field and scans the surface of the sample at the same time is used to perform the magnetization.
    Type: Grant
    Filed: December 13, 2012
    Date of Patent: July 11, 2017
    Assignee: TDK CORPORATION
    Inventors: Kenichi Suzuki, Tsutomu Chikamatsu, Akio Ogawa, Kyung-ku Choi, Ryuji Hashimoto
  • Patent number: 9691427
    Abstract: A method and apparatus for detecting tightness of a pick-up head, and a method and apparatus for controlling the moving of the pick-up head are disclosed. The method for detecting the tightness of the pick-up head includes moving the pick-up head to an inner area of the disc reading device when then disc reading device is powered on, moving the pick-up head to an outer area of the disc reading device within a predetermined time period, moving the pick-up head from the outer area of the disc reading device to the inner area at a constant speed by a first fixed force, and recording the moving duration for moving the pick-up head from the outer area of the disc reading device to the inner area at the constant speed.
    Type: Grant
    Filed: July 27, 2016
    Date of Patent: June 27, 2017
    Assignee: AutoChips Inc.
    Inventor: Jian Zhou
  • Patent number: 9536550
    Abstract: A cross-track profile of a known good test track on a recording medium is read during operation of a data storage device. Two or more center locations of the test track are determined at two or more different amplitude levels via a read transducer. A health condition of the read transducer is determined by comparing the two or more center locations of the test track with one another.
    Type: Grant
    Filed: November 19, 2015
    Date of Patent: January 3, 2017
    Assignee: SEAGATE TECHNOLOGY LLC
    Inventors: Minjie Ma, Edmun Seng, Tim Rausch, Edward Charles Gage
  • Patent number: 9304145
    Abstract: To detect near-field light, which is generated by a thermal assist type magnetic head element, and leaking light with high sensitivity and to more accurately obtain the spatial intensity distribution of a near-field light generation area, an inspection apparatus for a thermal assist type magnetic head element is adapted so that a distance between a cantilever and the surface of a specimen and the excitation amplitude of the cantilever are set to be small to detect near-field light with high sensitivity by the suppression of an influence of other light components, a distance between the cantilever and the surface of the specimen and the excitation amplitude of the cantilever are set to be large to detect other light components present in the vicinity of near-field light with high sensitivity by the suppression of an influence of the amount of detected near-field light when other light components are measured.
    Type: Grant
    Filed: July 30, 2015
    Date of Patent: April 5, 2016
    Assignee: Hitachi High-Tech Fine Systems Corporation
    Inventors: Kaifeng Zhang, Takenori Hirose, Masahiro Watanabe, Toshinori Sugiyama, Akira Tobita
  • Patent number: 9235726
    Abstract: A system for preventing data remanence in memory is provided. The system includes a computing device, a memory chip coupled to the computing device and including memory, and a heater, the heater configured to prevent data remanence in a memory by providing heat to at least a portion of the memory. The memory includes a plurality of bits configured to electronically store data.
    Type: Grant
    Filed: December 29, 2014
    Date of Patent: January 12, 2016
    Assignee: Elwha LLC
    Inventors: Roderick A. Hyde, Lowell L. Wood, Jr.
  • Patent number: 9202516
    Abstract: A diagnostic method and system comprising writing to a tape location of a tape medium using a first tape head as the tape medium is transported in a first direction, reading from the tape location using a second tape head as the tape medium is transported in the first direction, detecting an occurrence of a tape system failure, performing a diagnostic tape operation selected from a group consisting of writing to the tape location using the second tape head as the tape medium is transported in the first direction and reading from the tape location using the first tape head as the tape medium is transported in the first direction, differentially diagnosing a tape medium failure or a tape head failure depending on whether the tape operation failure is observed in response to performing the diagnostic tape operation, and posting a corresponding error code.
    Type: Grant
    Filed: June 30, 2014
    Date of Patent: December 1, 2015
    Assignee: Dell Products, LP
    Inventors: Dina A. Eldin, Robert C. Dawson
  • Patent number: 9165577
    Abstract: Provided herein is an apparatus, including a spinstand configured to position a disk in a testing orientation and a motor coupled to the spinstand, configured to rotate the disk. The motor comprises a fluid dynamic bearing.
    Type: Grant
    Filed: March 5, 2014
    Date of Patent: October 20, 2015
    Assignee: Seagate Technology LLC
    Inventors: Dale E. Kukacka, David G. Wobbe, Timothy Edward Langlais, ReAnn Dargus Robelia
  • Patent number: 9135938
    Abstract: A method of detecting a contact between a transducing head and a storage medium is provided. The method applies an input signal, having a select power level and known frequency, to an actuator for actuating the head. An output signal is obtained in response to the input signal. At least one signal component is extracted from the output signal at the same or a harmonic of the same known frequency as the input signal applied to the actuator. Whether the at least one extracted signal component indicates a contact between the head and the medium is determined. The power level of the applied wave pattern is increased incrementally until the extracted signal component indicates a contact between the head and the storage medium.
    Type: Grant
    Filed: May 20, 2014
    Date of Patent: September 15, 2015
    Assignee: SEAGATE TECHNOLOGY LLC
    Inventors: Dongming Liu, Lin Zhou, Adam Karl Himes, Lee Clifford Knippenberg, Michael Thomas Johnson
  • Patent number: 9030193
    Abstract: A system by which the proportion of ferromagnetic particles in a dielectric medium is measured. A magnetic field is generated by two signals in the medium: a low frequency feed and a relatively high frequency excitation. The feed magnetizes the ferromagnetic particles in the medium to the nonlinear range of the magnetization curve. The excitation is generated so that its spectrum is relatively wide and it is dense with frequency components. The level of the excitation is so high that the magnetic flux density in the medium corresponding to the excitation fluctuates nonlinearly, when the feed is at its peak value or near this. The magnetic field of the medium is measured by a secondary winding, and from the response signal produced by the sensor is detected the part resulting from the magnetic non-linearity, which part is the output signal. In the detection the response is multiplied by the signal, which arises magnetic field and includes the same random fluctuation as the response.
    Type: Grant
    Filed: January 19, 2011
    Date of Patent: May 12, 2015
    Assignee: Hemeltron
    Inventor: Arvi Kruusing
  • Patent number: 8860408
    Abstract: There is disclosed apparatus for supporting a disk drive, disk drive test apparatus and a method of testing a disk drive. The apparatus for supporting a disk drive includes: a housing, a slot for receiving a disk drive, and a plurality of isolators. The slot is received in the housing and has a longitudinal axis. The isolators are disposed between the slot and the housing for isolating the slot from the housing. The isolators are arranged with respect to the longitudinal axis such that the slot has a low rotational stiffness in the direction of the longitudinal axis relative to the rotational stiffness in at least one other direction.
    Type: Grant
    Filed: June 1, 2010
    Date of Patent: October 14, 2014
    Assignee: Xyratex Technology Limited
    Inventors: Alexander Stephen Kay, Philip Edward Long
  • Patent number: 8653824
    Abstract: A method for quasi-static testing a magnetic recording head read sensor is described. The method includes applying a first voltage to a heater in the magnetic recording head and measuring an output of the magnetic recording head read sensor while applying the first voltage to the heater and recording the measured output as a first set of measurements. The method further includes applying a second voltage to the heater in the magnetic recording head and measuring the output of the magnetic recording head read sensor while applying the second voltage to the heater and recording the measured output as a second set of measurements. The first and second sets of measurements are then compared.
    Type: Grant
    Filed: December 16, 2009
    Date of Patent: February 18, 2014
    Assignee: Western Digital (Fremont), LLC
    Inventors: Feng Liu, Mehran Zargari
  • Patent number: 8558146
    Abstract: Embodiments of the present invention are directed to establishing a desired position control over a workpiece by compensating for thermal cycling affecting a member supporting the workpiece during processing.
    Type: Grant
    Filed: March 17, 2008
    Date of Patent: October 15, 2013
    Assignee: Seagate Technology LLC
    Inventors: Steve Sheeran, Mark A. Toffle, Mark D. Anderson, Rodney D. Dahlenburg, Colin G. Presly, Paul J. Poisson
  • Patent number: 8553365
    Abstract: Systems and methods for improving loading and unloading of a read or write head onto and off of a disk medium. Particular embodiments may assist in loading a read or write head to, or unloading a read or write head from, a load location over a surface of a disk medium in such a manner that damage to the surface of the disk medium (e.g., load location) is either prevented or minimized. The prevention or reduction of damage may be achieved by ensuring that a read or write head has sufficient clearance over the surface of a disk medium as the read or write head moves over the surface (e.g., as the head moves parallel to the surface) during a head loading or unloading process.
    Type: Grant
    Filed: February 21, 2012
    Date of Patent: October 8, 2013
    Assignee: Western Digital (Fremont), LLC
    Inventors: Eugene Shapiro, Jagdeep S. Buttar, Trung Vinh, Tahir A. Ali
  • Patent number: 8544164
    Abstract: According to one embodiment, a head stack assembly cartridge is provided. The head stack assembly cartridge includes a base plate having a pivot shaft for pivotally mounting a head stack assembly and a base voice coil motor magnet attached to an inner surface of the base plate. The base voice coil motor magnet is arranged on the inner surface of the base plate to be adjacent to a coil of the head stack assembly pivotally mounted on the pivot shaft. The head stack assembly cartridge further includes a cover removably attached to the base plate and a pivot clamp removably attached to the cover and configured to secure the head stack assembly pivotally mounted on the pivot shaft.
    Type: Grant
    Filed: August 21, 2012
    Date of Patent: October 1, 2013
    Assignee: Western Digital Technologies, Inc.
    Inventors: Chunjer Chuck Cheng, Tao Lin, Gang Herbert Lin
  • Patent number: 8542453
    Abstract: An inspection method and inspection apparatus of a magnetic disk are provided. A gliding test and a certification test are performed at the same time by simultaneously moving a head for the certification test and a head for the gliding test with a heat distortion utilization mechanism (a micro thermal actuator) along a recording surface of the magnetic disk during rotation at a predetermined revolving speed. A flying height of the head for the gliding test is determined according to a revolving speed of the disk. When the flying height of the head for gliding test is determined according to the revolving speed at the certification test, the head for the gliding test is adjusted to a desired height by adjusting a variation of the heat distortion utilization mechanism disposed on the head for the gliding test. The gliding and certification inspections can be performed at the same time.
    Type: Grant
    Filed: January 9, 2012
    Date of Patent: September 24, 2013
    Assignee: Hitachi High-Technologies Corporation
    Inventors: Kyoichi Mori, Masanori Fukawa
  • Patent number: 8510931
    Abstract: A disc drive disc stack assembly and a method for forming the disc stack assembly to reduce servo pattern runout. The disc stack assembly includes a number of prewritten discs having a servo pattern and a disc alignment mark. The first step is to place a first disc about a spindle motor hub of the disc drive. The second step is to align a disc alignment mark of the first disc in relation to a direction of a biasing force. The third step is to apply the biasing force to the first disc to engage the first disc against the spindle motor hub. The fourth step is to repeat the first three steps for each remaining disc in the disc stack assembly. The final step is to clamp the prewritten discs with a disc clamp to secure the position of each prewritten disc relative to the spindle motor hub.
    Type: Grant
    Filed: October 17, 2001
    Date of Patent: August 20, 2013
    Assignee: Seagate Technology LLC
    Inventor: Arnold G. Slezak
  • Patent number: 8487609
    Abstract: A test apparatus can test a read head and/or a disk. The test apparatus includes a rotatable spindle adapted to hold the disk, and a holder oriented to hold the read head with its air bearing surface adjacent the major surface of the disk during testing. The holder includes a channel with a first side wall. The channel defines a channel longitudinal axis parallel to the first side wall. The channel also defines a lateral direction that is normal to the first side wall. A first gas jet points into the channel and impinges upon a top face of the read head.
    Type: Grant
    Filed: December 14, 2010
    Date of Patent: July 16, 2013
    Assignee: Microphysics, Inc.
    Inventor: Christopher Allen Lacey
  • Patent number: 8461834
    Abstract: A magneto-impedance sensor element is formed in a planar type structure in which an amorphous wire is incorporated in a substrate. The magneto-impedance sensor element includes a nonmagnetic substrate, an amorphous wire arranged in an aligning direction of a planar pattern that forms a detecting coil, a spiral detecting coil formed of a planar pattern and a cubic pattern on an outer periphery of the amorphous wire, a planar insulating portion that insulates the planar pattern from the amorphous wire, a wire fixing portion to fix the amorphous wire on an upper surface of the planar insulating portion, and a cubic insulating portion that insulates the cubic pattern from the amorphous wire.
    Type: Grant
    Filed: February 27, 2009
    Date of Patent: June 11, 2013
    Assignee: Aichi Steel Corporation
    Inventors: Yoshinobu Honkura, Michiharu Yamamoto, Katsuhiko Nishihata
  • Publication number: 20130107395
    Abstract: A magnetic head according to an embodiment includes: a spin-torque oscillator comprising a first ferromagnetic layer, a second ferromagnetic layer, a third ferromagnetic layer provided on the opposite side of the second ferromagnetic layer from the first ferromagnetic layer, a first nonmagnetic layer provided between the first ferromagnetic layer and the second ferromagnetic layer, a second nonmagnetic layer provided between the second ferromagnetic layer and the third ferromagnetic layer, a first electrode provided on a surface on the opposite side of the first ferromagnetic layer from the first nonmagnetic layer, and a second electrode provided on a surface on the opposite side of the third ferromagnetic layer from the second nonmagnetic layer. Magnetization precession is induced in each of the first through third ferromagnetic layers when current is applied between the first and second electrodes.
    Type: Application
    Filed: October 19, 2012
    Publication date: May 2, 2013
    Inventors: Tazumi Nagasawa, Hirofumi Suto, Kiwamu Kudo, Rie Sato, Koichi Mizushima, Tao Yang
  • Patent number: 8432630
    Abstract: A hard drive component test system is provided. The hard drive component test system includes a rack having multiple test bays with first test sub-assemblies mounted in respective ones of the of test bays. A test control system is electrically coupled to each of the first test sub-assemblies. Each of the test bays is configured to receive a second test sub-assembly and to engage the second test sub-assembly with the first test sub-assembly mounted in the respective bay to form a drive assembly. The test control system is configured to selectively execute a test process on the drive assemblies mounted in the rack.
    Type: Grant
    Filed: June 30, 2010
    Date of Patent: April 30, 2013
    Assignee: Western Digital Technologies, Inc.
    Inventors: Tao Lin, Gang Lin
  • Patent number: 8427692
    Abstract: A self-diagnosis function is used to acquire information showing the state of deterioration of a hard disk device, and when the hard disk device is deteriorated, a job is executed under the control which is different from that in the case where the hard disk device is not deteriorated. For example, copying job is executed in the HDD use mode in the case of non-deterioration, and copying job is executed in the HDD non-use mode (an image memory is used) in the case of deterioration. Further, the number of retrials by an alternative sector in the case of occurrence of errors of writing in a hard disk device in the course of job execution is changed according to the state of the deterioration.
    Type: Grant
    Filed: April 20, 2009
    Date of Patent: April 23, 2013
    Assignee: Konica Minolta Business Technologies, Inc.
    Inventor: Tatsuyoshi Haga
  • Publication number: 20130063139
    Abstract: An apparatus for inspecting a magnetic head device inspects an effective track width of a write track of each of magnetic head devices formed on a row bar in order to measure a two-dimensional distribution of magnetic fields generated by the magnetic head devices formed on the row bar while the apparatus is not affected by an external environment. The apparatus has a tray unit, a stage unit, a sample receiving and delivering unit, a magnetic field measuring unit and an effective track width measuring unit on a vibration isolation unit that blocks a vibration from the outside of the apparatus. The tray unit, the stage unit, the sample receiving and delivering unit, the magnetic field measuring unit, the effective track width measuring unit and the vibration isolation table are covered with a sound insulation unit that blocks noise from the outside of the apparatus.
    Type: Application
    Filed: August 2, 2012
    Publication date: March 14, 2013
    Applicant: HITACHI HIGH-TECHNOLOGIES CORPORATION
    Inventors: Teruaki TOKUTOMI, Takeshi SATOH, Akira TOBITA, Naoya SAITOH, Norimitsu MATSUSITA
  • Patent number: 8390271
    Abstract: The present invention relates to magnetic anchorage equipment comprising a frame able to contain a plurality of polar units, each of the plurality of polar units having a ferromagnetic polar element which identifies an anchorage surface and a self-testing unit for checking the magnetic equipment. The magnetic anchorage equipment is characterized in that the self-testing unit for checking the magnetic equipment is at least partly integrated in the frame.
    Type: Grant
    Filed: April 23, 2008
    Date of Patent: March 5, 2013
    Assignees: Tecnomagnete S.p.A., Politecnico di Milano
    Inventors: Michele Cardone, Giovanni Cosmai, Roberto Faranda, Antonino Giglio
  • Patent number: 8358127
    Abstract: A measuring circuit system in a magnetic field measuring apparatus of the invention has an amplifier and a band-pass filter connected in sequence on an output terminal side of the TMR element, the band-pass filter is a narrow-range band-pass filter such that a peak pass frequency of the filter that is a center is a basic frequency selected from a range of 10 to 40 GHz and a band width centered around the basic frequency is a narrow range of ±0.5 to ±4 GHz; and with the measuring circuit system, an SIN ratio (SNR) of 3 dB or greater is obtained, the SNR being defined by a ratio of an amplitude S of a high-frequency generated signal induced by the TMR element to a total noise N that is a sum of a head noise generated by the TMR element and a circuit noise generated by the amplifier. With such a configuration, an in-plane high-frequency magnetic field generated by a microwave-assisted magnetic head is reliably and precisely measured.
    Type: Grant
    Filed: April 7, 2010
    Date of Patent: January 22, 2013
    Assignee: TDK Corporation
    Inventors: Isamu Sato, Hiroshi Ikeda, Mikio Matsuzaki, Tetsuya Roppongi, Noboru Yamanaka, Tsutomu Aoyama
  • Publication number: 20120268112
    Abstract: The invention provides a method and apparatus for scanning a read/write head of a hard disk drive during manufacture. The method comprises: providing a magnetic sensor; moving the magnetic sensor relative to and in close proximity to the read/write head under test; obtaining measurements from the head under test or the sensor, representing a two-dimensional magnetic map; processing the map to obtain an accurate map of the head sensitivity of the head under test from which the key performance characteristics of the head can be obtained.
    Type: Application
    Filed: May 10, 2012
    Publication date: October 25, 2012
    Applicant: Xyratex Technology Limited
    Inventors: Nicholas J. GRANGER-BROWN, Graham R. EVELEIGH, Michael P. COOKE
  • Patent number: 8274751
    Abstract: A system and method for measuring the modulation between a magnetic head and a magnetic storage medium, such as a disk, is disclosed. A magnetic read/write head is positioned above a magnetic storage medium at a given flying height. The magnetic read/write head reads a signal from the magnetic storage medium. A tester measures an alternating electric current between the magnetic read/write head through the slider and the magnetic storage medium. A computer may then calculate the modulation by the magnetic read/write head based on the alternating electric current. A DC voltage to the head may be applied to lower the flying height of the magnetic head.
    Type: Grant
    Filed: April 1, 2011
    Date of Patent: September 25, 2012
    Assignee: SAE Magnetics (HK) Ltd.
    Inventors: Zhu Feng, Xiaofeng Zhang, Ellis T. Cha
  • Patent number: 8270118
    Abstract: According to one aspect of the present disclosure, a head stack assembly cartridge is provided. The head stack assembly cartridge includes a base plate having a pivot shaft for pivotally mounting a head stack assembly and a base voice coil motor magnet attached to an inner surface of the base plate. The base voice coil motor magnet is arranged on the inner surface of the base plate to be adjacent to a coil of the head stack assembly pivotally mounted on the pivot shaft. The head stack assembly cartridge further includes a cover removably attached to the base plate and a pivot clamp removably attached to the cover and configured to secure the head stack assembly pivotally mounted on the pivot shaft.
    Type: Grant
    Filed: October 30, 2009
    Date of Patent: September 18, 2012
    Assignee: Western Digital Technologies, Inc.
    Inventors: Chunjer Chuck Cheng, Tao Lin, Gang Herbert Lin
  • Publication number: 20120200287
    Abstract: There is disclosed a spinstand for testing a head gimbal assembly. The spinstand includes a gripper operable to grip the head gimbal assembly and a load pick device operable to hold a head gimbal assembly and to move the head gimbal assembly into an exchange position where it can be gripped by the gripper. In the exchange position part of the load pick device registers with the gripper and another part of the load pick device is spaced from the gripper so as to form a space between, in which space at least part of the head gimbal assembly is located in use.
    Type: Application
    Filed: October 19, 2010
    Publication date: August 9, 2012
    Applicant: Xyratex Technology Limited
    Inventors: Ian Stanley Warn, Andrew William Atkins
  • Patent number: 8214718
    Abstract: A system and method for erasure flagging for errors-and-erasures decoding in storage devices includes determining a deviation measure between a read/write head position relative to a track of symbols in storage media. A reliability value is determined for the symbols based on the deviation measure. Flagging the symbols with a reliability value below a threshold as erasures is performed. The symbols are decoded using errors-and-erasures decoding in an iterative procedure.
    Type: Grant
    Filed: June 19, 2008
    Date of Patent: July 3, 2012
    Assignee: International Business Machines Corporation
    Inventors: Theodore A. Antonakopoulos, Charalampos Pozidis, Maria Varsamou
  • Patent number: 8174781
    Abstract: A method for screening a magnetic-recording head utilizing a simulated-cross-track-gain profile of the magnetic-recording head to provide a manufacturing-qualified, magnetic-recording head. The method includes measuring a track profile of the magnetic-recording head, and providing the simulated-cross-track-gain profile of the magnetic-recording head synthesized utilizing the track profile of the magnetic-recording head. The method also includes calculating a peak-to-peak value of the simulated-cross-track-gain profile, and applying a selection criterion based on the peak-to-peak value of the simulated-cross-track-gain profile to screen the magnetic-recording head for use as the manufacturing-qualified, magnetic-recording head.
    Type: Grant
    Filed: May 5, 2008
    Date of Patent: May 8, 2012
    Assignee: Hitachi Global Storage Technologies, Netherlands B.V.
    Inventors: Scott E. Heeren, Masaki Kohno, Tue Ngo
  • Publication number: 20120105056
    Abstract: There is disclosed apparatus for supporting a disk drive, disk drive test apparatus and a method of testing a disk drive. The apparatus for supporting a disk drive includes: a housing, a slot for receiving a disk drive, and a plurality of isolators. The slot is received in the housing and has a longitudinal axis. The isolators are disposed between the slot and the housing for isolating the slot from the housing. The isolators are arranged with respect to the longitudinal axis such that the slot has a low rotational stiffness in the direction of the longitudinal axis relative to the rotational stiffness in at least one other direction.
    Type: Application
    Filed: June 1, 2010
    Publication date: May 3, 2012
    Applicant: Xyratex Technology Limited
    Inventors: Alexander Stephen Kay, Philip Edward Long
  • Patent number: 8169750
    Abstract: A removable cartridge for magnetic head and disk testers is disclosed. The removable cartridge includes: a base plate; a first end of an actuator rigidly fixed to the base plate; an HGA mounting block rigidly fixed to a second end of the actuator; a first end of a flexure rigidly coupled to the HGA mounting block; and a second end of the flexure rigidly coupled to the base plate.
    Type: Grant
    Filed: March 14, 2011
    Date of Patent: May 1, 2012
    Assignee: Guzik Technical Enterprises
    Inventors: Nahum Guzik, Brice Arnold, Forest Ray
  • Patent number: 8139306
    Abstract: A system and method for measuring the modulation between a magnetic head and a magnetic storage medium, such as a disk, is disclosed. A magnetic read/write head is positioned above a magnetic storage medium at a given flying height. The magnetic read/write head reads a signal from the magnetic storage medium. A tester measures an alternating electric current between the magnetic read/write head through the slider and the magnetic storage medium. A computer may then calculate the modulation by the magnetic read/write head based on the alternating electric current. A DC voltage to the head may be applied to lower the flying height of the magnetic head.
    Type: Grant
    Filed: November 4, 2004
    Date of Patent: March 20, 2012
    Assignee: SAE Magnetics (HK) Ltd.
    Inventors: Zhu Feng, Xiaofeng Zhang, Ellis T. Cha
  • Patent number: 8099852
    Abstract: A method for assembling an image capturing device is provided. The image capturing device includes a light-pervious module, an image sensor and a binding material. The image sensor has a light sensing region for converting an imaging light into an electronic signal. The binding material is used for binding articles together and curable by a curing process. Firstly, the light-pervious module and the image sensor together are releasably bound together via the binding material, thereby defining a close space for accommodating the image sensor. Then, a testing process is performed to detect a clean condition of the close space. If particles present in the close space are detected, the light-pervious module is detached from the image sensor, a cleaning process is done to remove the particle, and the light-pervious module and the image sensor are releasably bound together to define the close space again. Afterwards, the binding material is cured.
    Type: Grant
    Filed: March 6, 2009
    Date of Patent: January 24, 2012
    Assignee: Primax Electronics Ltd.
    Inventor: Jui-Hsiang Lo
  • Patent number: 8093888
    Abstract: A head holder includes a first and second blocks connected each other with a predetermined gap between the blocks by a flexible coupling portion. The second block supports the first block swingably by increasing a width of either one of spaces of the predetermined gap on opposite sides of the coupling portion and narrowing the other space by bending the coupling portion by a piezo actuator. A magnetic head is dynamically moved in a direction crossing a track by swinging a head assembly fixed to the first block.
    Type: Grant
    Filed: March 5, 2007
    Date of Patent: January 10, 2012
    Assignee: Hitachi High-Technologies Corporation
    Inventor: Fujio Yamasaki
  • Patent number: 8063630
    Abstract: In testing thin-film magnetic heads, first, a back surface opposite to a medium facing surface of each of a plurality of thin-film magnetic heads is attached to a first surface of a first plate of a jig, the jig including the first plate of rubber having the first and second surfaces facing toward opposite directions, and a second plate greater in rigidity than the first plate and bonded to the second surface of the first plate. Next, the plurality of thin-film magnetic heads and the jig are mounted on a metal plate having a flat top surface, such that the medium facing surfaces of the thin-film magnetic heads touch the top surface of the metal plate. Next, heat-generating components of the plurality of thin-film magnetic heads mounted on the metal plate are energized.
    Type: Grant
    Filed: March 14, 2008
    Date of Patent: November 22, 2011
    Assignee: TDK Corporation
    Inventors: Takamitsu Kamimura, Masato Sugahara, Kenji Yumoto
  • Publication number: 20110210723
    Abstract: Methods of performing electrostatic discharge testing on a transaction card are disclosed. A transaction card may be placed on an insulated surface. A grounding probe may be placed at a first location on the transaction card. A discharge probe may be charged to a known voltage level. The discharge probe may then be discharged at a second location on the transaction card. A discharge wave shape may be recorded from the ground probe, and one of a pass condition and a fail condition may be assigned based on at least the value of the known voltage level as compared to a reference voltage level. The first location and the second location may each be selected from a plurality of areas on the transaction card.
    Type: Application
    Filed: January 24, 2011
    Publication date: September 1, 2011
    Applicant: Visa U.S.A. Inc.
    Inventors: Mustafa Cemal Top, Edward Kurtek, Johan Ras, Dung Huynh, Stan Weitz, Chris Stanley Nelson
  • Patent number: 7987583
    Abstract: A step portion for mounting a row bar is provided at a table stepping down from the face of the table, and by lowering a pair of hooks crossing over the step portion in its width direction, a row bar held by the hooks is mounted on the step portion. While interposing the row bar mounted on the step portion between a pair of hooks and a side face of the step portion, the side in longitudinal direction of the row bar and the bottom face thereof are butted to the bottom face and the standing up side face of the step portion to position two axes of the row bar among XYZ directions, successively, positioning of the row bar in one remaining direction along longitudinal direction of the row bar mounted on the step portion is performed by moving the table in the one remaining axial direction.
    Type: Grant
    Filed: March 20, 2008
    Date of Patent: August 2, 2011
    Assignee: Hitachi High-Technologies Corporation
    Inventors: Teruaki Tokutomi, Yoshinori Kitano
  • Patent number: 7990642
    Abstract: Various embodiments of the present invention provide systems and methods for validating elements of storage devices. A an example, various embodiments of the present invention provide semiconductor devices that include a write path circuit, a read path circuit and a validation circuit. The write path circuit is operable to receive a data input and to convert the data input into write data suitable for storage to a storage medium. The read path circuit is operable to receive read data and to convert the read data into a data output. The validation circuit is operable to: receive the write data, augment the write data with a first noise sequence to yield a first augmented data series; and augment a derivative of the first augmented data series with a second noise sequence to yield the read data.
    Type: Grant
    Filed: April 17, 2009
    Date of Patent: August 2, 2011
    Assignee: LSI Corporation
    Inventors: Yuan Xing Lee, George Mathew, Shaohua Yang, Hongwei Song, Weijun Tan, Hao Zhong
  • Patent number: 7965460
    Abstract: A device comprising at least one sensor configured to sense disturbances applied to the data storage device and to generate signals based on the sensed disturbances, and a controller configured to receive the signals from the at least one sensor and to detect jerk events in the sensed disturbances based at least in part on vector differentials of the received signals.
    Type: Grant
    Filed: August 20, 2009
    Date of Patent: June 21, 2011
    Assignee: Seagate Technology LLC
    Inventor: Mark L. Elliott