Patents Represented by Attorney Won Tae C. Kim, Esq.
  • Patent number: 7193815
    Abstract: A read/write head for use in a perpendicular magnetic recording head in a data storage system. The read/write head includes a write section that is comprised of a first pole layer, a second pole layer, a third pole layer, and a shield layer. The third pole layer defines a write pole tip, and the third pole layer and the shield layer are separated from each other to define a write gap therebetween. At least part of the shield layer has a generally uniform width, and wherein the write pole tip defines a track width that is substantially equal to the uniform width of the shield layer. According to one embodiment the entire shield layer has a generally uniform width that is substantially equal to the track width. According to another embodiment, the shield layer includes a lower section and an upper section, wherein the lower section has a generally uniform width along its entire length, and wherein the upper section is wider than the lower section.
    Type: Grant
    Filed: April 6, 2004
    Date of Patent: March 20, 2007
    Assignee: Western Digital (Fremont), Inc.
    Inventors: Kroum S. Stoev, Francis H. Liu, Yugang Wang
  • Patent number: 6900958
    Abstract: A method is disclosed for improving head position accuracy in a disk drive during track following of concentric data storage tracks through real-time identification of external vibration and monitoring of write-unsafe (WUS) occurrences. In the method, after a seek operation to a predetermined data storage track, the track is followed using a servo control loop having a nominal gain and responsive to a position error signal (PES). After waiting a vibration detection delay period, occurrences of the PES exceeding a WUS limit are counted generating a WUS limit exception count. Also, a property of a variance is determined from spectral power values generated from the PES during track following. If the WUS limit exception count exceeds a first threshold, and if the property of the variance exceeds a second threshold, the nominal gain is increased to a vibration gain within a frequency band, to attenuate the effect of external vibration.
    Type: Grant
    Filed: July 31, 2003
    Date of Patent: May 31, 2005
    Assignee: Western Digital Technologies, Inc.
    Inventors: Li Yi, Yanbin Song, David A. Spaulding, Arafat M. Butt, Robert J. McNab, David D. Nguyen
  • Patent number: 6898044
    Abstract: A method is disclosed for selecting format specific parameters in a disk drive comprising a control system and a plurality of disk surfaces each having a surface format for storing data, wherein at least one surface format is different than other surface formats. The method includes initializing the disk drive for operation, receiving a data transfer command, and selecting a disk surface for performing data transfer operations based on the received data transfer command. The method further includes selecting a format specific data structure corresponding to the selected disk surface, calculating a format specific variable using the selected format specific data structure, and performing the data transfer operations by the control system based on the calculated variable.
    Type: Grant
    Filed: April 30, 2003
    Date of Patent: May 24, 2005
    Assignee: Western Digital Technologies, Inc.
    Inventor: Nalin H. Chheda
  • Patent number: 6898052
    Abstract: A spindle motor for use in a disk drive includes a spindle motor base and a motor shaft. The motor shaft has a central axis. The spindle motor includes a spindle motor hub rotatably coupled to the spindle motor base, the spindle motor hub including a central magnetic metal portion disposed adjacent a distal end of the motor shaft. The spindle motor includes a ball bearing set disposed between and in mechanical communication with the spindle motor hub and the motor shaft for rotatably coupling the spindle motor hub to the spindle motor base. The spindle motor includes a shaft magnetic element attached to the motor shaft at the distal end adjacent the central magnetic metal portion, the shaft magnetic element being sized and configured to apply an attractive magnetic force to the central magnetic metal portion in a direction along the central axis for pre-loading the ball bearing set.
    Type: Grant
    Filed: December 19, 2003
    Date of Patent: May 24, 2005
    Assignee: Western Digital Technologies, Inc.
    Inventor: Kamran Oveyssi
  • Patent number: 6888697
    Abstract: A disk drive includes an enclosure including a disk drive base and a disk drive cover, a disk for storing data, a spindle motor attached to the disk drive base, the spindle motor for rotating the disk and including a fixed spindle shaft defining a longitudinal axis, and a disk plate attached to the disk drive base. The disk plate includes a plate body extending radially above the disk and spaced-apart longitudinally from the disk. The plate body is attached to the fixed spindle shaft.
    Type: Grant
    Filed: April 28, 2003
    Date of Patent: May 3, 2005
    Assignee: Western Digital Technologies, Inc.
    Inventor: Kamran Oveyssi
  • Patent number: 6882496
    Abstract: A band of data storage tracks adjacent to an initial OD (outer diameter) limit are analyzed to determine a track defect density based on flagged tracks within the band. If the defect density exceeds a predetermined threshold, them the disk drive is reconfigured by adjusting initial OD and ID (inner diameter) limits to exclude the analyzed band and to maintain a targeted storage capacity. Adjusting the initial OD and ID limits improves the disk drive's seek performance which would otherwise be disproportionately impacted by the defect density in the analyzed band.
    Type: Grant
    Filed: May 30, 2003
    Date of Patent: April 19, 2005
    Assignee: Western Digital Technologies, Inc.
    Inventors: Raffi Codilian, Dalwinder Singh
  • Patent number: 6867946
    Abstract: A disk drive is disclosed comprising a disk, a head actuated radially over the disk, and a spindle motor for rotating the disk. The spindle motor comprises a stator having at least one stator coil wrapped around a stator tooth. The spindle motor further comprises a hub rotated by the stator when current is applied to the stator coil, and a locking spring arm having a fixed base. The locking spring arm engages the hub when no current is applied to the stator coil, and the locking spring arm disengages from the hub when current applied to the stator coil generates a magnetic flux which pulls the locking spring arm away from the hub.
    Type: Grant
    Filed: January 31, 2002
    Date of Patent: March 15, 2005
    Assignee: Western Digital Technologies, Inc.
    Inventors: Keith R. Berding, John R. Gustafson
  • Patent number: 6865049
    Abstract: Methods and devices for converting the kinetic energy of the rotating spindle motor of a disk drive of a rechargeable battery operated mobile host device into electrical energy during braking of the rotating spindle motor. The converted electrical energy is conditioned and used to charge the rechargeable battery of the mobile host device.
    Type: Grant
    Filed: June 28, 2002
    Date of Patent: March 8, 2005
    Assignee: Western Digital Technologies, Inc.
    Inventors: Raffi Codilian, Timothy A. Ferris
  • Patent number: 6844996
    Abstract: A disk drive is disclosed comprising an enclosure, a disk, a head actuated radially over the disk, a spindle motor for rotating the disk, and a ratchet arm having a base end connected to the enclosure of the disk drive and a wind vane extending from the base end adjacent the disk. The ratchet arm engages the disk when the disk is not rotating, and the ratchet arm disengages from the disk due to windage pushing on the wind vane, the windage generated by the disk rotating at an angular velocity greater than a threshold.
    Type: Grant
    Filed: January 31, 2002
    Date of Patent: January 18, 2005
    Assignee: Western Digital Technologies, Inc.
    Inventors: Keith R. Berding, John R. Gustafson
  • Patent number: 6831810
    Abstract: A disk drive has an enclosure that includes a first portion and a second portion that is configured to mate with the first portion. A spindle motor is attached to the first portion and a disk is mounted to the spindle motor. A head stack assembly is pivotally coupled to the second portion prior to the first and second portions being mated to one another. The head stack assembly includes a read write head that is configured to read from and write to the recording surface of the disk after the first and second portions are mated to one another.
    Type: Grant
    Filed: August 30, 2002
    Date of Patent: December 14, 2004
    Assignee: Western Digital Technologies, Inc.
    Inventors: Walter W. Butler, Robert E. Lloyd
  • Patent number: 6816343
    Abstract: A disk drive includes a magnetic element and a coil. The magnetic element includes an inner magnet set including first and second inner magnets. The magnetic element further includes an outer magnet set including first and second outer magnets. The first outer magnet is circumferentially disposed along the first inner magnet. The second outer magnet is circumferentially disposed along the second inner magnet. The coil is attached to a coil support of an actuator and disposed overlapping within a magnet periphery of the magnetic element. The coil includes an inner segment, an outer segment, and a pair of side segments electrically connecting the inner and outer segments. The inner segment is disposed overlapping with the inner magnet set, the outer segment being disposed overlapping with the outer magnet set. Each of the side segments is disposed equally overlapping with the inner and outer magnet sets.
    Type: Grant
    Filed: January 31, 2003
    Date of Patent: November 9, 2004
    Assignee: Western Digital Technologies, Inc.
    Inventor: Kamran Oveyssi
  • Patent number: 6816342
    Abstract: A disk drive includes a magnetic element having an inner magnet and an outer magnet. The disk drive further includes a first coil. The first coil includes a first coil inner segment, a first coil outer segment, and a first coil radial segment disposed generally perpendicular to the first coil inner segment and the first coil outer segment. The first coil radial segment overlaps the inner and outer magnets within a magnet periphery throughout a fill range of motion of the actuator. The disk drive further includes a second coil. The second coil includes a second coil inner segment, a second coil outer segment, and a second coil radial segment disposed generally parallel to the first coil radial segment. The second coil radial segment overlaps the inner and outer magnets within the magnet periphery throughout the full range of motion of the actuator.
    Type: Grant
    Filed: January 31, 2003
    Date of Patent: November 9, 2004
    Assignee: Western Digital Technologies, Inc.
    Inventor: Kamran Oveyssi
  • Patent number: 6811427
    Abstract: A cable connector configured in accordance with a Serial Advanced Technology Attachment (SATA) standard. The cable connector includes a first electrical contact arrangement in accordance with a SATA standard and is configured to mate with a first blade connector having a second electrical contact arrangement also in accordance with the SATA standard. The cable connector includes a first blade-receiving portion for enclosing the first electrical contact arrangement, a housing for supporting the first blade-receiving portion and the first electrical contact arrangement, and a pair of laterally-opposed guide arms being integrally formed with the housing. The housing has a cable entrance end and a mating end. The guide arms project from the mating end of the housing and are disposed outside of the first blade-receiving portion.
    Type: Grant
    Filed: November 15, 2002
    Date of Patent: November 2, 2004
    Assignee: Western Digital Technologies, Inc.
    Inventors: William W. Garrett, Marc B. Goldstone, Dalwinder Singh, Colin W. Morgan, Mark A. Baskovich
  • Patent number: 6801389
    Abstract: A disk drive is disclosed employing a spindle motor comprising a hub ratchet arm disengaged through angular velocity. In one embodiment the ratchet arm is connected to the hub and engages a spindle shaft or a stator, and in an alternative embodiment the ratchet arm is connected to the spindle shaft or the stator and engages the hub. In one embodiment the ratchet arm disengages through centrifugal force, and in an alternative embodiment the ratchet arm disengages through an air bearing or windage.
    Type: Grant
    Filed: January 31, 2002
    Date of Patent: October 5, 2004
    Assignee: Western Digital Technologies, Inc.
    Inventors: Keith R. Berding, John R. Gustafson
  • Patent number: 6801404
    Abstract: A disk drive includes a disk drive base and a rotary actuator coupled to the disk drive base. The rotary actuator includes an actuator body including a bore defining a longitudinal axis. The rotary actuator further includes a coil portion including a coil and a support element for supporting the coil. The coil support element is integrally formed with the actuator body and radially extends from the actuator body. The coil support element has a coil supporting surface generally perpendicular to the longitudinal axis. The coil is attached to the coil supporting surface. The coil support element is sized and configured to support the coil and formed of a thermo-conductive material for dissipating heat from the coil.
    Type: Grant
    Filed: August 30, 2002
    Date of Patent: October 5, 2004
    Assignee: Western Digital Technologies, Inc.
    Inventor: Kamran Oveyssi
  • Patent number: 6798603
    Abstract: A disk drive is disclosed comprising a disk, a spindle motor for rotating the disk, an actuator arm, and a head coupled to the actuator arm. While powered down the head is latched in a parked position. During a start-up process, the spindle motor is controlled to rotate the disk toward an operating speed and the head is unlatched prior to the disk reaching the operating speed. If the disk drive is in a first spin-up mode (e.g., a normal spin-up mode) the head is unlatched relative to a first target speed, and if the disk drive is in a second spin-up mode (e.g., a re-sync spin-up mode) the head is unlatched relative to a second target speed greater than the first target speed.
    Type: Grant
    Filed: July 31, 2002
    Date of Patent: September 28, 2004
    Assignee: Western Digital Technologies, Inc.
    Inventors: Dalwinder Singh, Steven Nemshick
  • Patent number: 6790066
    Abstract: An apparatus is disclosed for securing a cable assembly having a connector within an enclosed electronic system which includes a housing with an aperture and an electronic subsystem mounted within the housing with an electrical port for receiving the connector. The apparatus includes a compressible grommet fixedly mounted within the housing. The apparatus further includes a first surface and a distal surface and a channel traversing through the grommet and having a first end at the first surface aligned with the aperture, and a distal end at the distal surface substantially aligned with the electrical port. The grommet is adapted to receive the connector at the first end and to guide the connector along the channel to the distal end and the electrical port wherein the connector may be thereafter inserted into the electrical port and is thereby restrained by the grommet.
    Type: Grant
    Filed: November 27, 2002
    Date of Patent: September 14, 2004
    Assignee: Western Digital Technologies, Inc.
    Inventor: Barry L. Klein
  • Patent number: 6791801
    Abstract: A pivot bearing cartridge for use in a head stack assembly. The cartridge includes a pivot shaft including a central axis, a shaft body and a shaft distal end. The cartridge includes a pivot sleeve disposed about the pivot shaft. The pivot sleeve includes a pivot sleeve annular body and a pivot sleeve closed end disposed adjacent the shaft distal end. The cartridge includes a ball bearing set disposed between and in mechanical communication with the shaft body and the pivot sleeve annular body. The cartridge includes a shaft magnet element attached to the shaft distal end adjacent the pivot sleeve closed end. The shaft magnet element is sized and configured to apply a magnetic force to the pivot sleeve in a direction along the central axis for pre-loading the ball bearing set.
    Type: Grant
    Filed: February 28, 2002
    Date of Patent: September 14, 2004
    Assignee: Western Digital Technologies, Inc.
    Inventor: Kamran Oveyssi
  • Patent number: 6791791
    Abstract: An aspect of the invention can be regarded as a disk drive that includes a disk drive base and a spindle motor hub rotatably coupled to the disk drive base. The disk drive further includes a first disk disposed about the spindle motor hub and having a first disk stiffness. The disk drive further includes a second disk disposed about the spindle motor hub and having a second disk stiffness different than the first disk stiffness. According to another aspect of the present invention, the second disk has a second disk thickness different than a first disk thickness. According to another aspect of the present invention, the second disk is formed of a second material having a second material stiffness different than a first material stiffness.
    Type: Grant
    Filed: November 30, 2001
    Date of Patent: September 14, 2004
    Assignee: Western Digital Technologies, Inc.
    Inventors: Steven J. Alfred, Raffi Codilian, Serge Hauert, Lin Yang
  • Patent number: 6781826
    Abstract: Disclosed is an external disk drive compatible with a SATA standard for attachment to a host having a conductive enclosure. The external SATA compatible disk drive includes a SATA device connector and an enclosure surrounding the external SATA compatible disk drive. The external SATA compatible disk drive further includes a SATA compatible cable having a disk drive end that is coupled to the SATA device connector of the disk drive and a host end for coupling to the host, wherein the SATA compatible cable is capable of delivering power signals to the external SATA compatible disk drive from the host. Also, the external SATA compatible disk drive includes a shield surrounding the SATA compatible cable that is coupled to the enclosure of the disk drive.
    Type: Grant
    Filed: December 24, 2002
    Date of Patent: August 24, 2004
    Assignee: Western Digital Technologies, Inc.
    Inventors: Marc B. Goldstone, Dalwinder Singh