For Rotary Carrier (e.g., Disc) Patents (Class 360/78.04)
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Patent number: 7830630Abstract: A detector recovers servo data from a servo signal generated by a read-write head, and determines the head-connection polarity from the recovered servo data. Such a detector allows a servo circuit to compensate for a reversed-connected read-write head, and thus allows a manufacturer to forego time-consuming and costly testing to determine whether the head is correctly connected to the servo circuit.Type: GrantFiled: November 5, 2001Date of Patent: November 9, 2010Assignee: STMicroelectronics, Inc.Inventor: Hakan Ozdemir
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Patent number: 7826163Abstract: A system is capable of detecting a “large” shock. In contrast to just any shock, a large shock exceeds some threshold of magnitude or duration and may generate particles and/or the deposit of particles on a recording head, which can result in write errors. Responsive to detection of a large shock, the system can take corrective action, such as executing one or more corrective action seeks after detection of the large shock or executing a series of corrective actions seeks during a certain number of load operations after detection of the large shock. RAW verifications may be performed to confirm correct write operation of the recording head after such corrective action.Type: GrantFiled: September 29, 2006Date of Patent: November 2, 2010Assignee: Seagate Technology LLCInventors: Brent Jay Harmer, Marinko Bosnich, Abhay Tejmal Kataria
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Patent number: 7821733Abstract: Provided are a read channel, storage drive and method using a measured error to determine coefficients to provide to an equalizer to use to equalize an input signal. A read channel is incorporated in a storage device to process signals read from a storage medium. An equalizer uses coefficients to equalize input read signals to produce equalizer output signals. A detector processes adjusted equalizer output signals to determine output values comprising data represented by the input read signals. An equalizer adaptor is enabled to provide a reference measured error and coefficients used to produce the adjusted equalizer signals that are associated with the reference measured error. The equalizer adaptor computes new equalizer coefficients to use to equalize input read signals that result in a new measured error from the detector and computes a new measured error for the new equalizer coefficients.Type: GrantFiled: August 8, 2008Date of Patent: October 26, 2010Assignee: International Business Machines CorporationInventors: Evangelos S. Eleftheriou, Robert Allen Hutchins, Jens Jelitto, Sedat Oelcer
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Patent number: 7818474Abstract: The present invention is directed towards reducing hard disk drive (HDD) activity by sharing the buffering activity between a provisional load sharing buffer (PLSB) and a time shift buffer (TSB). The HDD may be included in a digital host communications terminal (DHCT). Initially, the PLSB buffers initial streaming programs to accommodate for channel changes. Additionally, the streaming program is buffered in a standard definition quality regardless of the format of a connected television. Once a predetermined time has passed determined by the size of the PLSB without a channel change, the TSB begins buffering the streaming program. The TSB can then switch between buffering a high definition quality to a standard definition quality of a streaming high definition program depending on other factors to further decrease the HDD activity. Additionally, the TSB can be disabled to prevent buffering of the streaming program.Type: GrantFiled: September 29, 2006Date of Patent: October 19, 2010Inventors: Gary D. Hibbard, Dennis L. Jesensky
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Patent number: 7817370Abstract: A system and method to avoid disk lube pooling is presented. A track access monitor tracks the number of times that a program accesses a particular track located on a hard drive. When the track access monitor determines that the number of track accesses to a particular track exceed a track access threshold, the track access monitor invokes a sequence of events to scan adjacent tracks in order to uniformly redistribute lubrication over the hard drive. In one embodiment, the track access monitor incrementally performs the adjacent track scanning during hard drive idle periods, such as when the system waits for a password from a user or when the operating system conserves power and idles the hard drive due to lack of activity.Type: GrantFiled: March 28, 2007Date of Patent: October 19, 2010Assignee: Lenovo (Singapore) Pte. Ltd.Inventors: Daryl Carvis Cromer, Howard Jeffrey Locker, Jeffrey R. Hobbet, Randall Scott Springfield
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Patent number: 7813074Abstract: A mechanical transport device includes a system for transport; and a hard disk drive attached to the system. The hard disk drive comprises a magnetic recording disk to record data, a head to read or write the data to or from the disk, and a drop sensor designed to sense a shock condition. The system for transport may be a vehicle such as a car. Additional systems are also presented.Type: GrantFiled: April 21, 2008Date of Patent: October 12, 2010Assignee: Hitachi Global Storage Technologies Netherlands B.V.Inventors: Susumu Shimotono, Tetsuya Noguchi, Mitsuru Ogawa, Akiyoshi Tanaka
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Patent number: 7813076Abstract: A hard disk drive with a controller that determines a position error signal gain. The position error signal gain is determined from a total servo loop gain and a function that is defined by a slope of a line of A and B servo bits measured at N off-track positions. The function determines an actual plant gain and thus provides a more accurate position error signal gain.Type: GrantFiled: September 3, 2008Date of Patent: October 12, 2010Assignee: Samsung Electronics Co., Ltd.Inventors: Chang Ik Kang, Sang Hoon Chu
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Patent number: 7800856Abstract: A disk drive is disclosed comprising a head actuated over a disk having a plurality of data tracks and a first and second set of reserved tracks, wherein the first set of reserved tracks are located at a first radial location, and the second set of reserved tracks are located at a second radial location different than the first radial location. A write command is received from a host, wherein the write command comprises user data which is stored in a cache memory. When a power failure is detected, whether the head is nearer to the first or second set of reserved tracks is determined, and then the head is positioned to the nearest of the first and second set of reserved tracks. The user data stored in the cache memory is written to the reserved tracks, and the head is unloaded onto a ramp.Type: GrantFiled: March 24, 2009Date of Patent: September 21, 2010Assignee: Western Digital Technologies, Inc.Inventors: George J. Bennett, Dean M. Jenkins, Robert D. Catiller
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Patent number: 7800857Abstract: A disk drive is disclosed comprising an IR voltage detector operable to detect a resistive voltage due to a resistance of a voice coil in a voice coil motor, and a BEMF detector operable to subtract the resistive voltage from the voice coil voltage to generate a BEMF voltage. A gain Gr of the IR voltage detector is calibrated by: (a) adjusting a control current applied to the voice coil; (b) adjusting the gain Gr; (c) detecting and saving the BEMF voltage corresponding to the adjusted gain Gr; (d) repeating steps (b) and (c) at least once; (e) repeating steps (a) through (d) at least once; and (f) selecting an operating gain Gr of the IR voltage detector in response to the adjusted control currents, the adjusted gains Gr, and the saved BEMF voltages.Type: GrantFiled: April 30, 2009Date of Patent: September 21, 2010Assignee: Western Digital Technologies, Inc.Inventors: Charles J. Calaway, Ashok K. Desai
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Publication number: 20100232057Abstract: A data storage apparatus includes a data storage medium, a write element, a non-volatile cache memory circuit, and a controller circuit. The controller circuit is configured to record data on the data storage medium in groups of overlapping tracks using the write element. The controller circuit is configured to store a shingle block of data from a subset of the overlapping tracks in the non-volatile cache memory circuit, while at least a portion of the data in the shingle block of data is updated.Type: ApplicationFiled: March 11, 2009Publication date: September 16, 2010Applicant: Hitachi Global Storage Technologies Netherlands, B.V.Inventors: Marco Sanvido, Cyril Guyot, Anand Krishnamurthi Kulkarni, Zvonimir Bandic, Martin Chen
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Publication number: 20100232058Abstract: In an information recording apparatus such as a hard disk drive, a ramp for retreating its head from a recording medium when the apparatus is stopped is provided opposing the information recording medium. In such an information recording apparatus, the information recording medium may sometimes collide with the ramp when the apparatus falls down. By inclining a portion opposing the ramp of a glass substrate in the information recording medium, even if the information recording medium strikes the ramp, the information recording medium is prevented from being cracked.Type: ApplicationFiled: May 20, 2010Publication date: September 16, 2010Applicant: Konica Minolta Opto, Inc.Inventors: Hideki KAWAI, Katsuhiko ASAI
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Patent number: 7764458Abstract: An apparatus, method, and system for providing a fine adjustment for transducing head positioning in a hard disk drive (HDD). The apparatus, method, and system include reading a positioning error field wherein the resulting signal is a substantially sinusoidal position error signal (PES), filtering the PES to remove low frequencies and attenuate high frequencies, sample the filtered PES at a multiple of the channel frequency, filter the higher frequency harmonics, down sample the PES, and provide a signal proportional to the amplitude of the down sampled PES. This signal is the reference signal to the head positioning servo.Type: GrantFiled: August 25, 2009Date of Patent: July 27, 2010Assignee: Marvell International Ltd.Inventors: Pantas Sutardja, Michael B. Madden
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Publication number: 20100177418Abstract: A hard disk drive with a patterned disk that has a discrete track. The disk drive includes a controller that controls a head and a voice coil motor to optimize a writing of information onto the discrete track. Writing optimization can occur by initially writing a track of information and recording the write position. The written track is then located by reading the information with a read element of a drive head and analyzing a quality of the read signal, such as signal amplitude or error rate. The read position is then recorded. The information is erased and the head is moved. The process of writing, finding the written track location, storing the write and read positions and again moving the head is repeated. The write and read positions that provide the best quality signal is saved and subsequently used to write and read data on the discrete track.Type: ApplicationFiled: January 14, 2009Publication date: July 15, 2010Applicant: Samsung Electronics Co., Ltd.Inventors: Yawshing Tang, Carl Xiaodong Che
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Patent number: 7742893Abstract: A calibration circuit calibrates an adjustable capacitance of a circuit having a time constant depending on the adjustable capacitance. The calibration circuit outputs a calibration signal carrying information for calibrating the capacitor and includes a calibration loop.Type: GrantFiled: February 21, 2008Date of Patent: June 22, 2010Assignee: STMicroelectronics S.r.l.Inventors: Pierangelo Confalonieri, Riccardo Martignone, Marco Zamprogno
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Patent number: 7729076Abstract: Embodiments of the present invention allow for media erasure. Various embodiments allow for controlling an actuator based on feedback signal measurements and disk phase to seek a head across a surface of a disk systematically for an erasure operation. Also, in various embodiments, a substantially repeatable seek motion of a head across a stroke may be determined, and launch points at which the head is launched over a disk in the seek motion for erasing at least a portion of the disk are determined based on disk phase.Type: GrantFiled: May 18, 2007Date of Patent: June 1, 2010Assignee: Seagate Technology LLCInventors: Craig Smith, Brian Rigney, Todd Franks, Xin H. Yang, Stan Shepherd, Bruce Liikanen
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Patent number: 7729081Abstract: A hard disk drive with a circuit that provides a control signal to a voice coil motor to move a head across a disk of the drive. The drive includes a flex circuit that applies a bias force onto an actuator arm coupled to the head. The circuit includes a state estimator that provides a plurality of estimation errors and a bias estimator that creates a bias estimate. The bias estimate includes an average of the estimation errors and is a function of the flex circuit bias force. The bias estimate is used to create the control signal provided to the voice coil motor. The bias estimate reduces seek time during a seek routine.Type: GrantFiled: February 6, 2009Date of Patent: June 1, 2010Assignee: Samsung Electronics Co., Ltd.Inventor: Chang-Ik Kang
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Patent number: 7719784Abstract: According to an aspect of an embodiment, an apparatus, includes: a medium having inner and outer edges and including first and second servo regions extending radially, and containing first and second servo information written thereon, respectively, the first servo region extending outwardly from the inner edge to cover tracks, the first and second servo region having positioned adjacently across a circular boundary; a head for reading out said first servo information and said second servo information; and a processor for executing a process comprising: reading out the first or second servo information; and when controlling the track position across the boundary, adjusting the relation of the first and second servo information across the boundary in control the track position.Type: GrantFiled: July 17, 2008Date of Patent: May 18, 2010Assignee: Toshiba Storage Device CorporationInventors: Takeshi Hara, Yoshifumi Obara, Shigenori Yanagi
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Patent number: 7710683Abstract: A hard disk drive system that includes one or more rotating data storage platters, a drive controller and multiple actuator assemblies and corresponding respective read/write heads. The actuator assemblies are separately moveable for performing separate data seeks. The controller is configured to interleave the seek and read/write operations of the multiple actuator assemblies and read/write heads with one another.Type: GrantFiled: May 27, 2008Date of Patent: May 4, 2010Assignee: International Business Machines CorporationInventors: Jesse E. Craig, Stanley B. Stanski, Scott T. Vento
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Patent number: 7706094Abstract: A storage device receives and holds a storage medium that is subjected to first servo writing processing for writing servo information, a Gray code of which is offset, from an inner cylinder or an outer cylinder to a predetermined cylinder and, after the first servo writing processing, subjected to second servo writing processing for writing servo information from an opposite direction to the predetermined cylinder and in which Gray codes are written to be offset not to overlap in the first or second servo writing processing and the pieces of servo information having different mark patterns are written in the first servo writing processing and the second servo writing processing. The storage device acquires cylinder information and mark patterns from the servo information written in the held storage medium and controls a position of a head based on the acquired cylinder information and mark patterns.Type: GrantFiled: May 15, 2008Date of Patent: April 27, 2010Assignee: Toshiba Storage Device CorporationInventors: Takeshi Hara, Yoshifumi Obara, Yukio Abe, Shigenori Yanagi, Mitsuo Kamimura
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Patent number: 7706096Abstract: Embodiments of the present invention help to increase the capacity and the reliability of a disk drive device to improve the manufacturing yield thereof. An embodiment of the present invention sets a data track pitch for each head slider (recording surface) in accordance with head characteristics. This method for specifying the data track pitch is based on the distance between erase band ends (EBEs) of the both adjacent data tracks. The erase band of a data track is a band defined as the area where the already written data are erased in writing the data track. The distance between the erase band ends of the both adjacent data tracks corresponds to the width SW of the area which is not erased by the adjacent data tracks. Specifying the data track pitch based on this leads to increase in the data capacity of each recording surface and secure prevention of occurrence of a squeeze error.Type: GrantFiled: September 11, 2008Date of Patent: April 27, 2010Assignee: Hitachi Global Storage TechnologiesInventors: Hideaki Ito, Kazuyuki Ishibashi, Kazunari Tsuchimoto, Osamu Takazawa
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Patent number: 7701660Abstract: A control system includes a difference generating module for a rotating storage system that generates a position error signal based on a target position signal and a current position signal. A control module of the control system generates an output response based on the position error signal. A noise equalizer module of the control system generates a noise equalization signal that is based on a sensor signal, the output response and the position error signal. A compensation module of the control system adjusts at least one of the current position signal, the position error signal, and the output response based on the noise equalization signal.Type: GrantFiled: February 9, 2007Date of Patent: April 20, 2010Assignee: Marvell International Ltd.Inventor: Pantas Sutardja
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Patent number: 7684142Abstract: A disk device has a positioning control system which has a disturbance suppression function in which the disturbance is suppressed quickly to prevent vibration of the head. In a positioning system having a disturbance suppression function of a disk device, an interface circuit for setting a known disturbance frequency to an initial value from the outside is installed. An unknown disturbance frequency can be immediately suppressed, or disturbance frequency control can be started from a known disturbance frequency, and even if the frequency changes thereafter, the estimated frequency can follow up to the disturbance, and the vibration of the head can be quickly prevented.Type: GrantFiled: July 13, 2006Date of Patent: March 23, 2010Assignee: Toshiba Storage Device CorporationInventor: Kazuhiko Takaishi
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Publication number: 20100053802Abstract: One embodiment of the invention includes a disk-drive motor control system. The system comprises a seek mode power supply configured to provide a first voltage corresponding to a seek mode associated with a disk-drive voice control motor (VCM). The system also includes a track mode power supply configured to provide a second voltage corresponding to a tracking mode associated with the disk-drive VCM. The first voltage can be greater than the second voltage. The system further includes a disk-drive motor driver configured to provide a current to the disk-drive VCM at a first magnitude in the seek mode based on the first voltage, at a second magnitude in the tracking mode based on the second voltage, and at a third magnitude in a head-retraction mode.Type: ApplicationFiled: August 27, 2008Publication date: March 4, 2010Inventor: Masaki Yamashita
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Patent number: 7672073Abstract: A method for operating a head testing apparatus or, more generally, a host hard disk drive using a mounted hard disk that has had its servo track information pre-written in an external servo-writing apparatus rather than in the head testing or host apparatus itself. The method eliminates repeatable errors and repeatable runout by effectively replacing the pre-written servo tracks, which are eccentric, with new track profiles that are tracked like circular tracks. The problem of repeatable errors is caused by repeatable runout superimposed upon written-in position errors when a disk written in one machine is transferred to another. This problem is eliminated by forming IRON (Iterative Repeatable Runout Nulling) profile tracks from the initially pre-written servo tracks, where the IRON profile tracks are effectively tracked as concentric circular tracks and generate no PES.Type: GrantFiled: February 14, 2008Date of Patent: March 2, 2010Assignee: Headway Technologies, Inc.Inventors: Lou Shrinkle, Peter Crill, Matthew Yee, David Hu
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Patent number: 7667922Abstract: Bias force changes in a disk drive, including transient bias changes, are predicted and/or estimated. Bias compensation or change in bias compensation is calculated based on drive operating parameters such as seek length. Calculation can correspond to a modeled relationship of bias forces to seek length. Preferably, bias compensation calculation is adaptive and calculation parameters can be updated during normal read/write use of the disk drive.Type: GrantFiled: January 10, 2005Date of Patent: February 23, 2010Assignee: Seagate Technology LLCInventors: Jeff Nelson, Jeffrey V. DeRosa
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Patent number: 7667920Abstract: A method for correcting a track pitch error in servo tracks written on a magnetic recording media coupled with a disk surface, by using a subsequent servo-write pass, comprises propagating servo tracks across the magnetic recording media in a previous servo-write pass. The servo tracks have radial positioning servo code. The servo tracks enable a magnetic transducer to be positioned to at least one radial position on the magnetic recording media. At least one corrected radial reference point is calculated for the track pitch error written on the magnetic recording media, by identifying at least one inconsistency between a mechanical response of an actuator and the track pitch. A corrected location for at least one servo track is identified. At least one new servo track at the corrected location is propagated with the subsequent servo-write pass. Optimum data track distribution across the disk surface and optimum reading and writing of data to and from the magnetic recording media is enabled.Type: GrantFiled: December 28, 2007Date of Patent: February 23, 2010Assignee: Hitachi Global Storage Technologies Netherlands B.V.Inventors: Satyajit N. Patwardhan, Steven C. Smith
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Patent number: 7664617Abstract: Apparatus and computer program products are provided to monitor and report performance data of a device such as a data storage drive. A plurality of quantitative values are obtained from feedback and measurement mechanisms in a data storage device of a first model during operation of the storage device. The plurality of quantitative values are normalized. Then, one or more qualitative values are generated from one or more normalized quantitative values and evaluated against corresponding baseline performance values established for the first model.Type: GrantFiled: October 14, 2008Date of Patent: February 16, 2010Assignee: International Business Machines CorporationInventors: Paul M. Greco, Glen A. Jaquette
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Patent number: 7663832Abstract: A method and apparatus for exactly compensating for a track zero position when copying a reference servo pattern in a disc drive adopting a reference servo track copying method. The method of compensating for a track zero position in a reference servo track copy system for copying a reference servo pattern in a head disc assembly into which a reference disc, on which the reference servo pattern is recorded, produced offline and at least one blank disc are assembled, includes: searching for a collision position of an actuator arm against a stopper for limiting the displacement of the actuator arm on the reference servo pattern; calculating an optimal track zero position based on the searched collision position; and copying the reference servo pattern on all disc surfaces from the calculated optimal track zero position.Type: GrantFiled: November 28, 2005Date of Patent: February 16, 2010Assignee: Samsung Electronics Co., Ltd.Inventors: Da-woon Chung, Jun Jeong
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Patent number: 7652445Abstract: A disk drive controller including a differential voice coil motor control function is disclosed. The differential voice coil motor control function includes an on-chip compensation network for the inner control loop, including a resistor formed of one or more MOS transistors connected in series. The gate of the MOS transistors in the compensation network is driven with a bias voltage based on a tuning current, where the tuning current is derived so that it varies with process and temperature variations of the integrated circuit, for example with variations in an on-chip capacitor. The on-chip compensation network can be tuned with sufficient precision to properly compensate the inner control loop to provide the desired frequency response in driving the voice coil motor in the disk drive.Type: GrantFiled: April 10, 2007Date of Patent: January 26, 2010Assignee: Texas Instruments IncorporatedInventors: Degang Xia, Robert E. Whyte, Jr.
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Publication number: 20100007986Abstract: A storage medium having a boundary located along a surface of the storage medium that functions as a transition point for selectively operating a first writer and a second writer of a plurality of writers, where the location of the boundary is set based on writing capabilities of the plurality of writers.Type: ApplicationFiled: July 14, 2008Publication date: January 14, 2010Applicant: Seagate Technology, LLCInventors: HonYeong Mak, Lin Nah Lim, Det Hau Wu, Edmun ChianSong Seng, UttHeng Kan
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Patent number: 7643239Abstract: Embodiments of the present invention reduce the written-in run-out in servo data written to a storage medium. A set of servo controllers are evaluated and the controller having the best expected performance among the set is selected and employed. One embodiment of the present invention is a servo controller configured to select and employ a controller having a least amount of expected written-in run-out among a set of controllers. Another embodiment of the present invention is a method comprising a step for applying a set of controllers; and selecting a controller from the set of controllers with a least expected amount of written-in run out. Another embodiment of the present invention is a system comprising a servo controller for employing and selecting a disk controller that has a least expected amount of written-in run-out among a set of controllers.Type: GrantFiled: April 25, 2007Date of Patent: January 5, 2010Assignee: Seagate Technology LLCInventors: Yu Sun, Xiaoping Hu
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Patent number: 7636605Abstract: A feedback controller performs a feedback control based on an error between a target position and an actual position of a head. A model controller obtains a control command, a model position to be output as a command for the target position to the feedback controller, and a model velocity for the head to follow a target velocity, by using a preset control equation model, and obtains the control command and the model position with the target position as an input, based on a differential value of the target velocity corresponding to a remaining distance from the model position to the target position.Type: GrantFiled: March 19, 2007Date of Patent: December 22, 2009Assignee: Kabushiki Kaisha ToshibaInventor: Shinji Takakura
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Patent number: 7633707Abstract: A hard disk drive with a voice coil motor coupled to a head. The head moves relative to a disk. The voice coil motor receives a biasing voltage and has a back emf voltage. A test circuit is coupled to the voice coil motor to determine the back emf voltage. The back emf voltage can be used to analyze low frequency vibration in the disk drive. The test circuit can be constructed so that the back emf voltage is proportional to a pair of test resistors and/or a pair of test inductors. The biasing voltage allows the back emf voltage to be measured and analyzed while the head is at any location from the ID to the OD of the disk.Type: GrantFiled: February 5, 2008Date of Patent: December 15, 2009Assignee: Samsung Electronics Co., Ltd.Inventors: Yanning Liu, Seong Woo Kang, Seungman Chang
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Patent number: 7633706Abstract: Servo writer apparatus and associated method for writing servo information to a data storage device. The servo writer has an external positioner configured for contactingly positioning the actuator in relation to the storage medium. The servo writer furthermore has a contact torque control with executable instructions stored in memory that operably changes the actuator torque in relation to a change in the external positioner torque.Type: GrantFiled: September 29, 2006Date of Patent: December 15, 2009Assignee: Seagate Technology LLCInventor: Brian Rigney
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Patent number: 7630161Abstract: According to one embodiment, a servo writing apparatus that writes a multi-spiral servo pattern to a disk medium is disclosed. The apparatus has a servo controller that generates a servo clock determining a head seek start timing, a servo pattern generator that generates a sector index pulse determining the interval at which a multi-spiral servo pattern is written to the disk medium, a clock phase difference measuring unit that measures a phase difference between the servo clock and the sector index pulse, and a controller that adjusts the measured phase difference.Type: GrantFiled: December 20, 2007Date of Patent: December 8, 2009Assignee: Kabushiki Kaisha ToshibaInventors: Shouji Nakajima, Masahide Yatsu, Hideo Sado, Katsuki Ueda, Toshitaka Matsunaga, Seiji Mizukoshi, Shinichirou Kouhara
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Patent number: 7630163Abstract: A storage device includes a storage unit, a timer unit and a bias current applying unit. The storage unit stores, in advance, a value of a waiting time until application of a bias current to the driving unit to eliminate an external force applied to an actuator after completion of positioning, and a value of a bias current to be applied to the driving unit after the elapse of the waiting time, in association with a track position. The timer unit reads the waiting time from the storage unit and counts an elapse of the waiting time. The bias current applying unit reads the bias current value from the storage unit and applies the bias current to the driving unit after the elapse of the waiting time.Type: GrantFiled: August 25, 2008Date of Patent: December 8, 2009Assignee: Fujitsu LimitedInventor: Takahiro Aoki
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Patent number: 7626908Abstract: An object of the present invention is to record or reproduce time-sequential data to/from recording media exemplified by hard disks at the transfer speed closer to that of the recording medium.Type: GrantFiled: January 21, 2005Date of Patent: December 1, 2009Assignee: Sony CorporationInventors: Toshiyuki Nakagawa, Hiroaki Eto
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Patent number: 7626782Abstract: A disk drive is disclosed operable to seek a head from a first radial location over a disk to a second radial location over the disk. A reference signal is initialized, a feed-forward control signal is initialized, and a seek is initiated. During the seek operation, a position error signal (PES) is generated and saved, wherein the PES represents a position error of the head relative to the reference signal. The PES is filtered with a compensation filter to generate a feed-back control signal. The feed-back control signal is combined with the feed-forward control signal to generate a VCM control signal. When the seek is done, the saved PES is processed using an iterative learning control (ILC) algorithm to adjust at least one of the reference signal and the feed-forward control signal.Type: GrantFiled: July 23, 2008Date of Patent: December 1, 2009Assignee: Western Digital Technologies, Inc.Inventors: Jie Yu, Kuang-Yang Tu, Young-Hoon Kim, Wei Xi
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Patent number: 7626779Abstract: According to one embodiment, a disk drive includes a heating element which is provided on a head and generates heat when supplied with power, thereby to adjust a dynamic flying height of the head. A head-movement detecting unit detects the abnormal movement of the head, a value of which is larger than a preset movement value during a head positioning control. In this case, a heating-element controller stops supplying power to the heating element.Type: GrantFiled: June 20, 2008Date of Patent: December 1, 2009Assignee: Kabushiki Kaisha ToshibaInventor: Satoshi Kuwahara
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Patent number: 7619850Abstract: A magnetic disk apparatus includes: a driving unit; and control part configured to control the driving unit. The control part includes: a position error feedback control system and a two-degree-of-freedom control system. The position error feedback control system has an integrator and a phase-lead compensator and is operative to determine a position command based on a target position and a sensed position of the magnetic head, thereby performs feedback control on the driving unit. The two-degree-of-freedom control system receives as input a target moving distance of the magnetic head and outputs a current command to the driving unit by using a mathematical model of the driving unit. The control part updates the mathematical model, and has a first update mode in which the mathematical model is updated using the output of the phase-lead compensator while the output of the integrator is provided to the driving unit.Type: GrantFiled: March 20, 2008Date of Patent: November 17, 2009Assignee: Kabushiki Kaisha ToshibaInventor: Shinji Takakura
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Patent number: 7619848Abstract: A method of searching to find a servo pattern corresponding to a servo pattern copy includes unparking a magnetic head and moving the magnetic head onto an intermediate area of a rotating disk, moving the magnetic head to a servo pattern copy start area by applying an initial search current to a voice coil of a voice coil motor (VCM), periodically measuring the speed of the magnetic head, controlling the speed of the magnetic head by adjusting a search current to the voice coil so that the speed of the magnetic head converges to a pre-set speed, and confirming the servo pattern recorded in the servo pattern copy start area using the magnetic head.Type: GrantFiled: July 24, 2007Date of Patent: November 17, 2009Assignee: Samsung Electronics Co., Ltd.Inventors: Cheol-hoon Park, Ho-joon Choi
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Patent number: 7619845Abstract: A method and an apparatus to control a disc drive, and more particularly, a method and an apparatus to control a disc drive using an indirectly determined counter-electromotive force. The method of controlling the disc drive using a counter-electromotive force includes determining a change in a servo parameter of the disc drive; and controlling the disc drive based on the determined change.Type: GrantFiled: June 13, 2006Date of Patent: November 17, 2009Assignee: Samsung Electronics, Ltd.Inventor: Sang-chul Shin
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Patent number: 7612960Abstract: Embodiments of the present invention efficiently format long sectors, without decreasing the performance, in a magnetic disk drive in which servo sectors are radially formed at regular intervals, and make full use of the ECC performance that is enhanced by the long sectors. In one embodiment, a data format in each zone on a magnetic disk is completed by a plurality of tracks N (N is an integer, which is 2 or more). The storage capacity per track of the outermost radius zone Z#1 is 150 kB. In this zone, long sectors each having a length of 32 kB are formatted with the number of tracks per format N#1=3. The storage capacity per track of the innermost radius zone Z#m is 80 kB. In this zone, long sectors each having a length of 32 kB are formatted with the number of tracks per format N#m=2.Type: GrantFiled: November 9, 2005Date of Patent: November 3, 2009Assignee: Hitachi Global Storage Technologies Netherlands B.V.Inventors: Naoki Satoh, Terumi Takashi, Hitoshi Ogawa, Hiroyuki Tsuchinaga
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Patent number: 7605998Abstract: A settling judgment method judges whether an object is settled at a target position by using a settlement judgment formula set a slice value and number of continuous samples. The slice and number of continuous judgments of the judgment value of the settling judgment are judged by the slice value and number of samples which are set such that the maximum value of a maximum amplitude ratio (Rate), for each frequency of cyclic disturbance (Y), determined from the maximum amplitude values (Max1, Max2) of the judgment values when the cyclic disturbance is applied is contained within a predetermined position accuracy. Settlings can be judged at high-speed and accurately according to the settling judgment formula, and both an improvement of positioning accuracy and high-speed judgment can be implemented.Type: GrantFiled: June 19, 2006Date of Patent: October 20, 2009Assignee: Fujitsu LimitedInventor: Kazuhiko Takaishi
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Patent number: 7602581Abstract: Methods and apparatus of the present invention allow for interpolated Just in Time (iJIT) seek command control of hard drive actuators.Type: GrantFiled: October 10, 2007Date of Patent: October 13, 2009Assignee: Hitachi Global Storage Technologies Netherlands B.V.Inventors: Nyles Heise, Hung M. Vu
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Patent number: 7602580Abstract: An apparatus and method for loading and offloading a read/write head from a load ramp onto a disc are disclosed. The apparatus includes at least a basedeck supporting a spindle motor with an attached disc and an actuator assembly with a read/write head configured for communication with the disc, and a load ramp positioned adjacent the disc and configured for receipt of the read/write head. The actuator assembly includes at least an actuator motor magnet mounted to said basedeck, an actuator body attached to the basedeck and providing a voice coil configured for interaction with the actuator motor magnet, and a bias feature secured to said actuator body and configured for communication with the motor magnet such that when the read/write head is parked on the load ramp, the bias feature mitigates an unintentional engagement of the read/write head with the disc.Type: GrantFiled: June 1, 2007Date of Patent: October 13, 2009Assignee: The Board of Regents for Oklahoma State UniversityInventors: Ryan T. Ratliff, Prabhakar R. Pagilla
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Patent number: 7593180Abstract: A hard disc drive (HDD) data read control apparatus, medium, and method reading data from a disc having non-uniform track-to-track spacing. The data read control method of the HDD, in which data is read from a disc including non-uniform track-to-track spacing, includes seeking a target track by adopting an off track amount applied to a previously followed track, and reading the data while following the sought target track. Accordingly, production yield can be increased by making failure processing unnecessary even if a track-to-track spacing of a HDD is non-uniform.Type: GrantFiled: January 18, 2006Date of Patent: September 22, 2009Assignee: Samsung Electronics Co., Ltd.Inventors: Jong-yun Yun, Sang-hoon Chu
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Patent number: 7589925Abstract: A disk drive has multiple disk surfaces and corresponding heads, each disk surface includes multiple regions, and each head is for recording on and playback of information from a corresponding disk surface. The data track density in a first region on a first disk surface is different than the data track density in a second region on a second disk surface, and the first and second regions are radially similarly situated regions. A method of sequentially accessing data in the first and second regions includes sequentially accessing data tracks in the first region and then sequentially accessing data tracks in the second region.Type: GrantFiled: June 6, 2006Date of Patent: September 15, 2009Assignee: Maxtor CorporationInventors: Jim Chiao, Teddy Hadiono, Allen Cheng-wu Hu, Annie Mylang Le, Perry Neos, Chad Schroter, Eric Wong, Yan Zang, Charles W. Miller
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Patent number: 7586713Abstract: A control apparatus, storage apparatus and control method uses a correction value for head position written in a recording medium to control head position and prevents a use of a correction value that has improperly been read out. The apparatus comprises: an allowable range acquisition section that acquires a correction value allowable range which is a previously set allowable range of a correction value; and a head position control section that controls head position using a read out correction value in the case where the correction value that has been read out from the recording medium falls within the correction value allowable range acquired by the allowable range acquisition section.Type: GrantFiled: July 31, 2006Date of Patent: September 8, 2009Assignee: Fujitsu LimitedInventors: Fumiya Kudo, Mitsuo Kamimura
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Patent number: 7583469Abstract: An apparatus, method, and system for providing a fine adjustment for transducing head positioning in a hard disk drive (HDD). The apparatus, method, and system include reading a positioning error field wherein the resulting signal is a substantially sinusoidal position error signal (PES), filtering the PES to remove low frequencies and attenuate high frequencies, sample the filtered PES at a multiple of the channel frequency, filter the higher frequency harmonics, down sample the PES, and provide a signal proportional to the amplitude of the down sampled PES. This signal is the reference signal to the head positioning servo.Type: GrantFiled: December 28, 2006Date of Patent: September 1, 2009Assignee: Marvell International Ltd.Inventors: Pantas Sutardja, Michael B. Madden