Patents Examined by Dan I Davidson
  • Patent number: 7212367
    Abstract: A magnetic recording head comprises a write pole having a tip adjacent to an air bearing surface of the recording head, a return pole magnetically coupled to the write pole, a conductor positioned adjacent to an edge of the write pole at the air bearing surface, a first conductive heat sink connected to the conductor, and a second conductive heat sink connected to the conductor, wherein at least a portion of each of the first and second conductive heat sinks is positioned adjacent to the air bearing surface and wherein each of the first and second conductive heat sinks includes a structure for augmenting confinement of a magnetic write field adjacent to the write pole. Magnetic storage devices that include the magnetic recording head are also included.
    Type: Grant
    Filed: June 16, 2004
    Date of Patent: May 1, 2007
    Assignee: Seagate Technology LLC
    Inventors: Thomas William Clinton, Petrus Antonius van der Heijden, Michael Allen Seigler, Mark William Covington, Werner Scholz, Sharat Batra
  • Patent number: 7206147
    Abstract: In an apparatus for recording and regenerating data, a pass metric is calculated based on a likelihood converted from a previous calculation result iteratively until all pass metrics of the same data recorded many times on a recording medium are calculated, and then data recorded on the recording medium is decoded.
    Type: Grant
    Filed: April 28, 2005
    Date of Patent: April 17, 2007
    Assignee: Fujitsu Limited
    Inventors: Masakazu Taguchi, Akihiro Itakura, Akiyoshi Uchida
  • Patent number: 7206146
    Abstract: A hard disk drive (HDD) holds data using a biphase scheme. A plurality of matched filters are used to detect binary data represented by the biphase pattern without the need for synchronous sampling or equalization.
    Type: Grant
    Filed: October 27, 2004
    Date of Patent: April 17, 2007
    Assignee: Hitachi Global Storage Technologies Netherlands B.V.
    Inventors: David Timothy Flynn, Richard Galbraith, Travis Roger Oenning
  • Patent number: 7196860
    Abstract: An apparatus and method write data to a storage medium, and subsequently automatically refresh the data to avoid loss of the data due to spontaneous thermal degradation. The apparatus and method may check whether an indicator (also called “refresh indicator”) if saved contemporaneous with writing of the data satisfies a predetermined condition indicating that the data needs to be refreshed. If so, a “refresh” operation is performed, wherein the to-be-refreshed data is read from and written back to the same storage medium. The refresh indicator can be any parameter that indicates a need to refresh the data prior to occurrence of one or more soft errors. In one example, the apparatus and method read the data back contemporaneous with writing of the data, and measure an amplitude of a readback signal and store, as the refresh indicator, a predetermined fraction (e.g. half) of the measured value (i.e., a threshold number). When a current value of the amplitude falls below the stored value, the data is refreshed.
    Type: Grant
    Filed: September 12, 2003
    Date of Patent: March 27, 2007
    Assignee: Komag, Inc.
    Inventor: Michael Alex
  • Patent number: 7193800
    Abstract: A data recording medium has tracks with pseudo-noise (PN) sequences with good autocorrelation properties as servo information for controlling the position of the recording head. A first set of alternating tracks uses a leading pseudo-random binary sequence (PRBS), which is a PN sequence with good autocorrelation properties, and a following PRBS that is cyclically shifted from the leading PRBS. A second set of alternating tracks interleaved with the first set also has a leading PRBS and a following PRBS that is cyclically shifted from the leading PRBS, but the leading PRBS in each of the tracks in the second set is offset along-the-track from the leading PRBS in the tracks of the first set. The head positioning control system uses the leading PRBS to generate a servo timing mark (STM), the cyclic shift to generate track identification (TID), and the following PRBS from adjacent tracks to generate the head position error signal (PES).
    Type: Grant
    Filed: May 6, 2004
    Date of Patent: March 20, 2007
    Assignee: Hitachi Global Storage Technologies Netherlands B.V.
    Inventors: Jonathan Darrel Coker, David Timothy Flynn, Richard Leo Galbraith
  • Patent number: 7184232
    Abstract: An apparatus for driving a write head in response to a data signal includes: (a) a first drive unit coupled with the write head; (b) a second drive unit coupled with the write head; and (c) a control unit coupled with the first and second drive units. The control unit receives the data signal and generates control signals to the first drive and second drive units in response to the data signal. The control signals control the first drive unit to apply a first drive signal to a first write head side in a first signal polarity and control the second drive unit to apply a second drive signal to the a second write head side in a second signal polarity opposite to the first signal polarity when the data signal effects a signal excursion. The first drive signal and the second drive signal are equal in magnitude time coincident.
    Type: Grant
    Filed: September 18, 2003
    Date of Patent: February 27, 2007
    Assignee: Texas Instruments Incorporated
    Inventors: Motomu Hashizume, Jinguji Naoko, Indumini Ranmuthu, Neel Seshan
  • Patent number: 7154689
    Abstract: Methods for making a disk drive, apparatus for writing servo bursts on a disk, and disk drive apparatus are provided. The disk drive includes a disk and transducer adjacent to the disk. The transducer includes a read element and a write element. A width of the read element is determined. A servo track pitch is determined based on the read element width. Servo bursts are written in servo tracks on the disk with the write element based on the servo track pitch.
    Type: Grant
    Filed: September 20, 2004
    Date of Patent: December 26, 2006
    Assignee: Maxtor Corporation
    Inventors: Stanley H. Shepherd, Yu Sun, Lin Guo, John VanLaanen
  • Patent number: 7154690
    Abstract: Dynamically detecting off-track errors in a disk drive by adjusting transducer head position control parameters in response to shock events. In an embodiment, shock events with large magnitude trigger a severe shock timer which lengthens the write fault before write operations resume. In another embodiment, a lower shock threshold is used following an initial shock event. In yet another embodiment, a lower shock threshold is used if an accumulated average position error of the transducer head is large.
    Type: Grant
    Filed: April 19, 2005
    Date of Patent: December 26, 2006
    Assignee: Maxtor Corporation
    Inventors: Don Brunnett, John Purkett, Bruce Liikanen
  • Patent number: 7154687
    Abstract: Devices and methods for generating a magnetic head-specific overshoot current which is combined with an alternating current waveform into a write current used by the magnetic head to store information on a magnetic medium. A processor analyzes the frequency of incoming write data and retrieves from a data table of an overshoot current amplitude and an overshoot current phase. This amplitude and phase information is sent to an overshoot current generator to generate an overshoot current that is responsive to the dynamic impedance properties of a magnetic write head during operation. The data table may have information related to one or many write heads, and the data table may be further subdivided based on additional dynamic characteristics of a write head that may affect the impedance thereof.
    Type: Grant
    Filed: January 25, 2005
    Date of Patent: December 26, 2006
    Assignee: Hitachi Global Storage Technologies Japan, Ltd.
    Inventors: Hiroshi Ikekame, Takeo Yamashita
  • Patent number: 7154691
    Abstract: According to one aspect, an exemplary multi-format magneto resistive recording head is provided. The magnetic head includes a first set of data transducers configured transversely across a direction of tape transport, the first set of data transducers associated with a first data format, and a second set of data transducers configured transversely across the direction of tape transport, the second set of data transducers associated with a second data format, wherein the first set of data transducers and the second set of data transducers are separated by a distance along the direction of tape transport. In one example, the magnetic head includes a first raised elongated island positioned transversely across the direction of tape transport, the first island including the first set of data transducers, and a second raised elongated island positioned transversely across the direction of tape transport, the second island including the second set of data transducers.
    Type: Grant
    Filed: December 18, 2003
    Date of Patent: December 26, 2006
    Assignee: Quantum Corporation
    Inventors: Carolyn Girvin, Lee Jaderborg, Ming Ho Lau, Kenneth S. Franzel
  • Patent number: 7154688
    Abstract: In a disk device in which heads are positioned by a servo mechanism, the object of the present invention is to prevent data from being destroyed by incorrect selection of a head and to improve reliability in recording or reproducing information and to prevent format efficiency from being decreased thereby. For this object, a SAM pattern in a servo information region is changed for each head and recorded. Then, the SAM pattern is read to determine which head makes access to a disk surface and the head is compared with a head to which a direction of making access is given thereby to make an error check. Moreover, by the use of a marker pattern of rotational synchronization compensating data added to the servo information, an error check of the head making access to the disc surface is conducted.
    Type: Grant
    Filed: February 13, 2003
    Date of Patent: December 26, 2006
    Assignee: Hitachi Global Storage Technologies Japan, Ltd.
    Inventors: Iwao Oshimi, Kiyotada Itou, Katsumoto Onoyama, Yosuke Hamada
  • Patent number: 7154693
    Abstract: A HDD write driver circuit (10) having a boost current overshoot programmed by a plurality of pull-up devices (MP35, MP36, MP39, MP45). The pull-up strength of an inverter (20) is adjustably selected by programming pull-up PMOS devices, and less power is dropped across a resistor (R41) such that there is less boost current overshoot when an overshoot MSB is low.
    Type: Grant
    Filed: October 29, 2004
    Date of Patent: December 26, 2006
    Assignee: Texas Instruments Incorporated
    Inventor: John J. Price, Jr.
  • Patent number: 7149045
    Abstract: A magnetic recording device including a longitudinal magnetic recording medium. The longitudinal magnetic recording medium includes a magnetically soft underlayer disposed under a longitudinal recording layer. A perpendicular write head is utilized to write data to the longitudinal magnetic recording medium wherein the longitudinal recording layer is disposed within an effective write gap formed by the perpendicular write head and the underlayer. The longitudinal component of the perpendicular write head is sufficient to switch the magnetic grains in the recording layer in the presence of the perpendicular field. The magnetic recording medium can have a high areal density and improved magnetic properties.
    Type: Grant
    Filed: October 30, 2003
    Date of Patent: December 12, 2006
    Assignee: Maxtor Corporation
    Inventors: Michael L. Mallary, Steven Marshall, Mourad Benakli, Adam F. Torabi
  • Patent number: 7149043
    Abstract: In order to account for the misplacement of a write element during a servowriting process, the width of the information being written can be varied. In a self-servowriting disk drive, for example, the write current supplied to a read/write head can be adjusted to vary the width of information, such as servo bursts, written by the head. By calibrating the head and determining the misplacement of the head while writing, an edge of a servo burst can be placed in the desired position regardless of the misplacement of the head simply by adjusting the width of the written burst. This description is not intended to be a complete description of, or limit the scope of, the invention. Other features, aspects, and objects of the invention can be obtained from a review of the specification, the figures, and the claims.
    Type: Grant
    Filed: April 5, 2004
    Date of Patent: December 12, 2006
    Assignee: Matsushita Electric Industrial Co., Ltd.
    Inventor: Richard M. Ehrlich
  • Patent number: 7149055
    Abstract: A magnetic recording head comprises a write pole having a tip adjacent to an air bearing surface of the recording head, a return pole magnetically coupled to the write pole, a conductor positioned adjacent to at least one edge of the write pole at the air bearing surface for carrying current to produce a magnetic field that saturates at least a portion of the write pole and augments a write field, a first conductive heat sink connected to a first end of the conductor, and a second conductive heat sink connected to a second end of the conductor. Disc drives that include the recording head are also included.
    Type: Grant
    Filed: December 15, 2003
    Date of Patent: December 12, 2006
    Assignee: Seagate Technology LLC
    Inventors: Thomas William Clinton, Petrus Antonius van der Heijden, Michael Allen Seigler, Jonathan D. Hannay
  • Patent number: 7142383
    Abstract: A recording/playback recording medium comprising an elongated, flexible recording/playback medium having a predetermined width and a predetermined length, together defining a recording/playback area capable of providing a plurality of elongated recording/playback tracks; and information located on at least two tracks, a first track being recorded from the beginning of the first track in a first direction until the track is filled, a second track being recorded in a second opposite direction, the tracks being partitioned to define sectors having identifiable locations, the first, second, and subsequent tracks if necessary being recorded in a serpentine manner, the information recorded on the tracks being recorded by a helical scan.
    Type: Grant
    Filed: September 1, 2004
    Date of Patent: November 28, 2006
    Assignees: Sony Corporation, Sony Electronics Inc.
    Inventors: Gregory R. Clemons, Steven A. Tice
  • Patent number: 7139143
    Abstract: A signal processing device for analog-to-digital converting a burst signal has a feature of selecting a data bus to notify a disk control device of a conversion result via an NRZ data bus. The disk control device stores the result of the analog-to-digital conversion of the servo positional signal. The positional signal of a head of the disk device is digitized in a R/W channel. Sampling for digital conversion is performed in only a window which is defined only in the vicinity of peaks of the positional signal. The values of peaks which are obtained by sampling are averaged by an averaging circuit. This enables the influence of noise occurred outside of the window to be eliminated. Although the noise in the window is sampled, its adverse influence is suppressed by the averaging processing.
    Type: Grant
    Filed: March 17, 2003
    Date of Patent: November 21, 2006
    Assignee: Hitachi, Ltd.
    Inventors: Motoyasu Tsunoda, Yukie Miyazawa, legal representative, Hitoshi Ogawa, Ryutaro Horita, Takashi Nara, Masatoshi Nishina, Katsumi Yamamoto, Shoichi Miyazawa, deceased
  • Patent number: 7139141
    Abstract: In a tape drive for storing and retrieving information to and from a media, a system for optimizing write performance includes a tape head and a controller. The tape head may include a write element. The controller may be for optimizing write performance in response to at least one media information signal that is stored on a media cartridge.
    Type: Grant
    Filed: May 12, 2003
    Date of Patent: November 21, 2006
    Assignee: Storage Technology Corporation
    Inventors: James C. Cates, Keith Gary Boyer, Mark Hennecken, Robert G. Brocko, Larry Blanchard, Michael L. Leonhardt
  • Patent number: 7136239
    Abstract: A data storage device exhibiting reduced pad regions includes a read/write channel to convert transduced waveforms from a storage medium into recovered digital information. The recovered digital information is communicated from the read/write channel to a controller. The read/write channel includes an analog stage and a digital stage, which function independently. While the digital stage is engaged in the task of recovering servo data, the analog stage may be engaged in the task of recovering user data. Initially, the controller generates a control signal commanding the read/write channel to read and recover servo data. In the wake of the last unit of servo data having been processed by the analog stage of the read/write channel, the controller commands the read/write channel to read user data from the disc. Therefore, the analog stage of the read/write channel reads user data, while the digital stage finishes processing the servo data.
    Type: Grant
    Filed: June 4, 2003
    Date of Patent: November 14, 2006
    Assignee: Seagate Technology LLC
    Inventors: Kendall H Fung, Hui Su, Dan J Coonen
  • Patent number: 7133233
    Abstract: A disk drive includes recording media having one or more recording surfaces, one or more transducer heads positionable relative to the recording surfaces by an actuator operating within a head position servo loop, and a data transfer driver. A preamplifier in the data transfer driver includes one or more head interfaces, each head interface for controlling a transducer head for read and write operations, and a mode controller for controlling each head interface based on configuration information for selectively (i) reading data from at least one recording surface, (ii) writing data to at least one recording surface, and (iii) simultaneously reading data (such as a reference pattern) from at least one recording surface and writing data (such as servo patterns) to at least one recording surface.
    Type: Grant
    Filed: October 24, 2000
    Date of Patent: November 7, 2006
    Assignee: Maxtor Corporation
    Inventors: Charles D. Ray, Gary Lee, Tony Hurtado