Rotary Carrier Patents (Class 360/73.03)
  • Patent number: 6826005
    Abstract: A disk array unit connected to a host unit to give information thereto and receive information therefrom. The disk unit includes a plurality of disk units for storing information transmitted from the host unit and a management information recording device, formed by utilizing information storage areas in the disk units, for causing information relating to a logical unit for storing information from the host unit to correspond to information relating to the units. The invention further includes a control unit, when there is no access from the host unit to the logical unit for a predetermined time, for determining the disk units corresponding to the logical unit based on information recorded in the management information recording device and performing power saving of power supply for the disk units.
    Type: Grant
    Filed: April 14, 2003
    Date of Patent: November 30, 2004
    Assignee: Hitachi, Ltd.
    Inventors: Kazuo Hakamata, Kenichi Takamoto, Masaaki Kobayashi
  • Publication number: 20040223251
    Abstract: A disk drive system is described which includes a disk having a magnetic surface and a motor for rotating said disk, a magnetic head being movable relative to said magnetic surface. The motor generates a back electromotive force voltage having different phases and the system comprising a plurality of switches for switching said back electromotive force voltage, a control circuit to control said plurality of switches to supply said back electromotive force voltage to direct said head to a parking position. The system also comprises a comparator adapted to compare a single phase of the back electromotive force voltage with the sum of the other phases of said back electromotive force voltage. The comparator generates an output signal representative of the comparation and the system comprises a logic block controlled by the output signal of the comparator. The logic block is adapted to determine time periods and a control sequence of the switches which is associated to said time periods.
    Type: Application
    Filed: May 7, 2003
    Publication date: November 11, 2004
    Inventors: Gianluca Ventura, Alberto Salina, Alessandra Schenone, Fabio Ramaioli, Luca Anostini
  • Publication number: 20040196586
    Abstract: Disclosed are a system, a method, and a computer program product to disable the power-saving sleep mode of a disk drive if the drive detects an error at spinup that is a result of the read/write head sticking to the disk surface. The power saving sleep mode is avoided to prevent further spinup problems.
    Type: Application
    Filed: April 7, 2003
    Publication date: October 7, 2004
    Applicant: International Business Machines Corporation
    Inventors: Daniel James Winarski, Susan Encinas
  • Patent number: 6801381
    Abstract: A magnetic disk apparatus includes a spindle motor for rotating a magnetic disk. Either a first pulse-train signal or a second pulse-train signal is selectively generated. The first and second pulse-train signals are different from each other in pulse frequency. When the first pulse-train signal is generated, the spindle motor is controlled to rotate at a first rotational speed in response to the first pulse-train signal. When the second pulse-train signal is generated, the spindle motor is controlled to rotate at a second rotational speed in response to the second pulse-train signal. The second rotational speed differs from the first rotational speed.
    Type: Grant
    Filed: March 27, 2001
    Date of Patent: October 5, 2004
    Assignees: Victor Company of Japan, Ltd., Teac Corporation
    Inventors: Hiroshi Iwai, Takeshi Suzuki, Hiroshi Tsuyuguchi
  • Patent number: 6801382
    Abstract: Currents of sine waveforms can be fed through coils by a relatively small-sized circuit, and thereby, highly dense magnetic storage can be realized with less rotation variations and a driving control circuit of a motor rotating at a low noise level can be provided. A coil of one phase of a three-phase brushless motor is driven with full amplitude at which an applied voltage becomes equal to a source voltage, and a coil of one of other phases is driven with gradually changing voltages so that a current of sine waveform is delivered, and a coil of the remaining phase is driven by feedback control so that a total current flowing through all coils becomes a predetermined current value.
    Type: Grant
    Filed: April 17, 2002
    Date of Patent: October 5, 2004
    Assignees: Renesas Technology Corp., Hitachi Tohbu Semiconductor, Ltd.
    Inventors: Reiichi Kimura, Yasuhiko Kokami, Kunihiro Kawauchi, Minoru Kurosawa, Kichiya Itagaki
  • 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: 6791782
    Abstract: A method and an apparatus select the operational spindle rotation rate for a disk drive based on measured performance of the head-disk assembly. The position error values are measured and analyzed to generate a position error metric. Based on the value of the position error metric, an operational spindle rotation rate is selected for use when the head-disk assembly is combined with a controller to produce a disk drive.
    Type: Grant
    Filed: January 31, 2002
    Date of Patent: September 14, 2004
    Assignee: Western Digital Technologies, Inc.
    Inventors: Raffi Codilian, William D. Johns, Joseph M. Viglione
  • Patent number: 6788488
    Abstract: A method and apparatus for a variable mode multi-media data object storage device. Large digital objects can be quickly downloaded in approximately a minute. The digital objects can be utilized or played back at real-time speeds. Utilization or playback consumes minimal power, allowing the disk to support portable devices operating on battery power. The storage device uses multiple disk rotation speeds to support multiple modes of operation. The storage device operates in at least two modes of disk drive operation, supporting a fast platter rotation speed for writing and a slower platter rotation speed for reading. The multiple rotation speeds operate in conjunction with a head assembly configured with at least one head for reading and multiple heads for writing. When writing, the disk spins at the faster rotation speed. When in utilization or playback mode, the disk spins at the slower, power conserving rotation speed.
    Type: Grant
    Filed: May 24, 2001
    Date of Patent: September 7, 2004
    Assignee: Qualcomm, Incorporated
    Inventors: Franklin P. Antonio, Sanjay Jha
  • Patent number: 6785199
    Abstract: A drive device has a feed mechanism that causes a control object to move in order to control the positioning of the control object, a motor that serves as the drive source of said feed mechanism, and a control means that controls this motor. The control means has an operation history memory unit that stores the operation history of whether the motor is doing an initial start or a restart, and a command selection unit that selects control commands and outputs them to said motor based on information stored in said operation history memory unit. Because intermittent operation that repeatedly drives and stops the motor occurs when there is a restart, the thermal shutdown associated with overheating of the driver IC is avoided, and any difference between the feed amount due to the control means and the actual feed amount can be prevented.
    Type: Grant
    Filed: October 22, 2001
    Date of Patent: August 31, 2004
    Assignee: Sony Computer Entertainment Inc.
    Inventors: Hiroshi Ohtsu, Hironobu Amemiya, Masaki Sugiyama
  • Patent number: 6771451
    Abstract: A method for centering the disk of a disk stack assembly. The method includes the step of applying a torque to the disk stack and spinning the disks. Both the torque and the spinning speed are less than normal operating values. A series of radial forces may then be applied to the disk stack. The series of forces will cause the rotating disks to self center. The rotating disks are eventually spun down and a full torque is applied to the disk stack to secure the disks.
    Type: Grant
    Filed: September 4, 2001
    Date of Patent: August 3, 2004
    Assignee: Samsung Electronics Co., Ltd.
    Inventors: Frank Ivan Morris, Scott Tran, Joseph Chang
  • Patent number: 6771440
    Abstract: In a first aspect, a method of operating a disk drive includes detecting a trigger event during non-idle operation of the disk drive, and responding to the detected trigger event by performing a predictive failure analysis with respect to the disk drive. According to a second aspect, a method of operating a disk drive includes performing a predictive failure analysis with respect to the disk drive at a regular time interval, detecting a trigger event during non-idle operation of the disk drive, and responding to the detected trigger event by reducing the regular time interval at which the predictive failure analysis is performed. Numerous other aspects are provided.
    Type: Grant
    Filed: December 18, 2001
    Date of Patent: August 3, 2004
    Assignee: International Business Machines Corporation
    Inventor: Gordon James Smith
  • Patent number: 6762899
    Abstract: A method and apparatus for estimating the flyheight of an airbearing slider in a storage device using variable spindle velocity. The slider floats on an airbearing over a rotating storage disk. The storage disk includes a washboard-sequence having washboard-sections each comprising surface profile variations having a different pitch. The pitches are selected from within a range of values likely to excite an airbearing resonance of the slider as the storage disk rotates at a plurality of discrete velocities. For each of the washboard-sections and at each of the velocities, a maximum amplitude of flyheight modulation of the slider resulting from the slider floating over that washboard-section is measured as the storage disk rotates at that velocity. A determination is made of the velocity/washboard-section combination that caused the largest measured flyheight modulation.
    Type: Grant
    Filed: March 16, 2001
    Date of Patent: July 13, 2004
    Assignee: Hitachi Global Storage Technologies Netherlands B.V.
    Inventors: Hal Hjalmar Ottesen, Gordon James Smith
  • Patent number: 6754025
    Abstract: A spindle motor control for a disk drive including a spindle motor for rotating a data disk at a desired rotational speed, and a data transducer head positionable relative to selected ones of a multiplicity of concentric data tracks formed on a data storage surface of the data disk by a head position actuator structure operating within a head position servo loop, wherein the concentric data tracks are periodically interrupted by a plurality of servo sectors per rotation, each servo sector recorded with head position information.
    Type: Grant
    Filed: January 12, 2000
    Date of Patent: June 22, 2004
    Assignee: Maxtor Corporation
    Inventors: Stanley H. Shepherd, Michael Anthony Moser, Yakov Lifchits, Ching-Tzuen Tarn, Mohamad A. Rezvani
  • Patent number: 6751041
    Abstract: A method and an apparatus select the spindle rotation speed for writing servo tracks to a disk based on measured performance of the head-disk assembly. The position error values are measured and analyzed to generate a position error metric. Based on the value of the position error metric, a spindle rotation speed is selected for use when writing servo tracks to a disk.
    Type: Grant
    Filed: January 31, 2002
    Date of Patent: June 15, 2004
    Assignee: Western Digital Technologies, Inc.
    Inventors: Raffi Codilian, Joseph M. Viglione
  • Publication number: 20040109255
    Abstract: A method and device for controlling power consumption in a computer having a storage device including a motor and a storage medium is disclosed. The method comprises supplying a first power level to the motor of the storage device to spin the storage medium at a first rotational velocity, detecting a first predetermined condition and responsive to the detection of the first predetermined condition, supplying a second power level to the motor of the storage device to spin the storage medium at a second rotational velocity. A number of user defined preferences and system conditions in the computer may be taken into account in determining the second power level to the storage medium.
    Type: Application
    Filed: December 10, 2002
    Publication date: June 10, 2004
    Inventor: Michael C. Walz
  • Patent number: 6747832
    Abstract: A disk drive has a data recording medium such as a disk, a spindle motor for rotating the disk, disk rotation speed controlling logics for supplying a spindle current to the above described spindle motor to rotate the disk at a constant speed, a head unit for accessing the disk, an actuator for moving the head unit, and head position controlling logics for driving the actuator and controlling the position of the head unit. The head position controlling logic obtains the value of the spindle current and controls the position of the head unit on the basis of the above described spindle current value by using the fact that the spindle current varies according to variations in the position of the head unit.
    Type: Grant
    Filed: March 27, 2001
    Date of Patent: June 8, 2004
    Assignee: Hitachi Global Storage Technologies Netherlands, B.V.
    Inventors: Masashi Kisaka, Yutaka Ozawa, Kenji Toga
  • Publication number: 20040100722
    Abstract: The present invention provides a magnetic disk storage system including a spindle motor that rotates a magnetic disk, a spindle motor drive circuit that rotatably drives the spindle motor, a magnetic head that performs reading of information on the magnetic disk, a voice coil motor that moves the magnetic head, and a voice coil motor drive circuit that drives the voice coil motor. When the magnetic head is loaded from a standby position to the surface of the magnetic disk, the rotational speed of the spindle motor is made slower than a rotational speed at a normal operation. Upon power-off, the spindle motor drive circuit is caused to carry out a stepup converter operation to thereby generate a voltage higher than a back electromotive voltage, and causes a control circuit and a drive circuit to operate by the high voltage to thereby enable speed control at the movement of the magnetic head to a predetermined standby position.
    Type: Application
    Filed: October 24, 2003
    Publication date: May 27, 2004
    Applicants: Renesas Technology Corp., Hitachi ULSI Systems Co., Ltd.
    Inventor: Yasuhiko Kokami
  • Patent number: 6741414
    Abstract: A method and system for joint spindle speed and head position control in rotating media storage systems are described. A controller changes the rotation speed of a spindle assembly based upon the position information of a desired data sector. This controller may also control the actuator assembly based upon the position information of the desired data sector.
    Type: Grant
    Filed: June 15, 2000
    Date of Patent: May 25, 2004
    Assignee: Tokyo Electron Limited
    Inventors: Stephen Boyd, Sunil C. Shah, Mark Erickson, Ioannis Kanellakopoulos
  • Patent number: 6738213
    Abstract: A disk drive includes a disk from and to which information can be read and written; a disk driving motor for spinning the disk; a read/write head disposed in the vicinity of the disk; a head transfer mechanism for transferring the read/write head in the radial direction of the disk; and a controller for controlling the overall disk drive. The disk drive is connected to a host control unit through a Universal Serial Bus interface. When a step signal for driving the head transfer mechanism is output at a point at which the disk driving motor is activated, the controller immediately deactivates the disk driving motor and only actuates the head transfer mechanism to move step by step.
    Type: Grant
    Filed: August 30, 2001
    Date of Patent: May 18, 2004
    Assignee: Alps Electric Co., Ltd.
    Inventor: Munehisa Haitani
  • Patent number: 6735035
    Abstract: In cold weather, the higher torque required for normal spinning operation of a spindle motor assembly in a direct access storage device due to the increased viscosity of the grease, is overcome by localizing the heating to the spindle motor assembly to reduce the viscosity of the grease, and then let a disk driven self heat during and after spin-up of the spindle motor assembly.
    Type: Grant
    Filed: November 20, 2000
    Date of Patent: May 11, 2004
    Assignee: International Business Machines Corporation
    Inventors: Gordon James Smith, George Willard Van Leeuwen
  • Publication number: 20040085873
    Abstract: A mass memory storage device for reading data stored on a mass memory storage medium on which the data is stored at a substantially uniform density including a support arrangement configured to receive and support the medium. A drive arrangement is operatively connected to the support arrangement such that the drive arrangement rotates the medium at a substantially constant rotational speed when the device is operated in its intended way. A read head for reading the data stored on the medium is positioned adjacent to the medium with the read head being movable relative to the medium. A read channel arrangement for processing the data read by the read head is operatively connected to the read head. The read channel arrangement has a substantially continuously variable read channel data processing rate which varies according to the rate at which the read head reads the data from the medium. In a preferred embodiment, the device is a CD drive.
    Type: Application
    Filed: October 30, 2003
    Publication date: May 6, 2004
    Inventors: Jeffrey G. Reh, Tracy D. Harmer, Curtis H. Bruner
  • Publication number: 20040085668
    Abstract: A voltage determination unit dynamically determines a first voltage required to maintain the rotational speed of a spindle motor (SPM) at the rated rotational speed according to a rotational state of the SPM. A CPU determines a second voltage for driving the SPM by software processing in a software control mode. A voltage generator generates the first voltage determined by the voltage determination unit as driving voltage in a hardware control mode and generates the second voltage determined by the CPU as the driving voltage in the software control mode. A driver circuit drives the SPM by the driving voltage generated with the voltage generator.
    Type: Application
    Filed: October 6, 2003
    Publication date: May 6, 2004
    Applicant: KABUSHIKI KAISHA TOSHIBA
    Inventor: Nobuyuki Sakamoto
  • Publication number: 20040061966
    Abstract: An apparatus for exactly positioning a medium mounted on a spindle is provided, whereby the apparatus comprises a device for continuously changing the angular position of said medium with respect to a predefined reference position by rotating said spindle. Additionally, the apparatus comprises a friction element for braking said spindle at a predetermined position, not allowing a swing back.
    Type: Application
    Filed: July 29, 2003
    Publication date: April 1, 2004
    Inventors: Ruediger Friedrich Berger, Andreas Dietzel, Thomas Frank, Volker Heinrich
  • Patent number: 6714489
    Abstract: A control system for a compact disc jukebox detects skips in the compact disc by reading an apparent elapsed time signal from the compact disc that is encoded on the compact disc. A timer is simultaneously started and outputs a real elapsed time signal. A comparison is made between the real elapsed time signal and the apparent elapsed time signal. If the difference between these two signals exceeds a predetermined amount of time, a skip is recorded. The detection of a skip may be recorded as to a particular selection on a particular CD, along with the time of the skip. Appropriate action may be taken in response to the recording of a skip, such as cancelling the selection or stopping the CD.
    Type: Grant
    Filed: April 2, 2003
    Date of Patent: March 30, 2004
    Assignee: Rowe International Corporation
    Inventors: Jeffrey J. Kalis, Frederick G. Robinson, Richard Van Dyk
  • Patent number: 6714377
    Abstract: A data storage device includes a disc stack, a rotary actuator having an arm coupled to a transducer head, and support structure for receiving the arm with a reduced incidence of sliding contact therewith. The arm is separated from the support means, and then moved so that the head is above a disc surface for storing data. After the disc stack reaches its nominal rotation speed, the head is loaded so that it can transfer data. During periods of non-activity, the head is raised (unloaded) again and the arm is placed on the support means. This reduces a risk of damage in the presence of shocks while minimizing particle generation induced by friction.
    Type: Grant
    Filed: July 31, 2001
    Date of Patent: March 30, 2004
    Assignee: Seagate Technology LLC
    Inventors: Gary Edwin Bement, Mark Andrew Chapin, Michael David Mundt
  • Publication number: 20040057150
    Abstract: A magnetic disk apparatus includes a low-rotation mode for decreasing the revolution number of a disk, in the low-rotation mode, any control signal for decelerating the disk is not generated to permit it to be decelerated owing to inertial drive and when a detected speed falls below a target speed, the disk is accelerated to thereby realize power saving.
    Type: Application
    Filed: April 30, 2003
    Publication date: March 25, 2004
    Applicant: HITACHI, LTD.
    Inventors: Masaki Odai, Kyo Akagi, Ryuji Tsuchiyama
  • Patent number: 6710961
    Abstract: A floppy disc drive apparatus includes a spindle motor, a magnetic head, a drive mechanism, a mechanism controller, a floppy disc controller, and a universal serial bus interface. The spindle motor rotatably drives a floppy disc at a rotational speed of 600 rpm or more. The magnetic head reads and records data on the floppy disc. The drive mechanism has an actuator that scans the magnetic head in a radial direction of the floppy disc. The mechanism controller controls the drive mechanism to thereby reproduce and record specified data on the floppy disc. The floppy disc controller transfers and receives data to and from the mechanism controller at a transfer rate of 1 Mbit/s or greater. The universal serial bus interface allows the floppy disc controller to transfer and receive data to and from an external apparatus at a transfer rate of 1 Mbit/s or greater.
    Type: Grant
    Filed: September 20, 2000
    Date of Patent: March 23, 2004
    Assignee: Sankyo Seiki Mfg. Co., Ltd.
    Inventors: Makoto Fujishima, Hisashi Fukuzawa
  • Patent number: 6710952
    Abstract: A computer hard disk drive has a drive controller that monitors the condition of the head-disk interface within the drive. The drive normally operates under ambient or relatively low internal pressure. However, when the drive is in imminent risk for a head-disk interface failure, the drive is pressurized to allow the air bearing surfaces of the heads to achieve a greater flying height above the surfaces of their respective disks, thereby delaying the onset of a catastrophic head-disk interface failure. In addition, the spindle rotation rate and/or the slider head access rate are decreased to avoid hastening the imminent failure. Measurements of the condition and stability of the head-disk interface inside the drives are made by monitoring data error rates, head flying height, and other performance variables.
    Type: Grant
    Filed: January 19, 2000
    Date of Patent: March 23, 2004
    Assignee: Hitachi Global Storage Technologies Netherlands, B.V.
    Inventor: Gordon James Smith
  • Patent number: 6693761
    Abstract: In a magnetic disk unit, in the control of a load/unload function of a magnetic head relative to a magnetic disk, the magnetic disk and the magnetic head are prevented from contacting each other and damage thereto is avoided by utilizing a shallow dual-step subambient pressure slider and carrying out loading/unloading at a rotational speed lower than a rated rotational speed of the normally operated magnetic disk at which writing and reading (R/W) of data to and from the magnetic disk by the magnetic head is normally carried out.
    Type: Grant
    Filed: March 2, 2001
    Date of Patent: February 17, 2004
    Assignee: Hitachi, Ltd.
    Inventors: Nobuyuki Ishii, Kiyoshi Hashimoto, Shinsuke Higuchi, Kenichi Gomi
  • Patent number: 6693762
    Abstract: The invention provides an apparatus (10) and method for monitoring the load/unload process of a head-gimbal assembly (HGA) (14), disk (12) and ramp (16) combination. A ramp strain arm (18) is used to monitor the entire load/unload process. The ramp strain arm (18), on which the ramp (16) is mounted, includes force sensors (46,48) that measure the friction force between the HGA (14) and ramp (16) as well as the air-bearing force on the slider (30) of the HGA (14) during the load/unload process. The signals form the force sensors (46,48) are input to a computer (22) through an interface circuit (24) for recording and analysis in order to evaluate the performance of the combination of the HGA (14), disk (12) and ramp (16).
    Type: Grant
    Filed: July 27, 2001
    Date of Patent: February 17, 2004
    Assignee: Data Storage Institute
    Inventors: Bo Liu, Yaolong Zhu
  • Patent number: 6687077
    Abstract: The present invention is directed to a disk drive that employs a proximity recording interface in which a slider that carries a head is designed to remain in contact with the disk during data transfer operations to achieve a high data density. In particular, the present invention is directed to cleaning debris from a pad on the slider that carries the head. The debris, if allowed to accumulate, can reach a depth at which the head is spaced from the disk at a distance which adversely affects the transfer of data with the disk. In one embodiment, the spin motor of the disk drive is caused to rotate at a lower angular velocity than during normal data transfer operations, preferably using open loop control, while the actuator of the disk drive is used to radially displace the slider and associated head, also preferably using open loop control. For a constant angular velocity of the disk, the change in radial position causes different areas of the pad to be contacted and cleaned by the disk.
    Type: Grant
    Filed: October 7, 1999
    Date of Patent: February 3, 2004
    Assignee: Maxtor Corporation
    Inventors: Jim French, Mike McNeil, Ross Chessman
  • Patent number: 6680811
    Abstract: A disk drive utilizes a slider that is designed to fly very high or well above the surface of the disk when loading onto the disk and until a reading or writing operation requires the head to go to a relatively low-flying position with respect to the disk. Thus, the slider has two or more altitudes at which it flies depending on the operating conditions of the disk drive. The different altitudes of the slider are achieved by adjusting three primary variables: the rotational speed of the disk, selecting the radial position of the slider/actuator arm, and by the gram load. Other factors that may be used to tune this performance include pitch static attitude, pitch stiffness, and air bearing surface design.
    Type: Grant
    Filed: October 9, 2001
    Date of Patent: January 20, 2004
    Assignee: International Business Machines Corporation
    Inventors: Donald R. Gillis, Mike Suk
  • Publication number: 20040004782
    Abstract: The object is to raise controller gain while absorbing magnet position dispersion in a motor, and implement rotation control that is resistant to the influence of disturbance. There are provided a spindle motor 3 that performs rotational drive of a predetermined drive object, and a controller 121 that controls rotational drive of this spindle motor 3 by comparing a pulse time in rotational drive of this spindle motor 3 with a predetermined target time and performing feedback; and also provided is a peak filter 122 that compensates control by the controller 121 by varying the target time dynamically so as to suppress the rotation frequency and higher harmonic components thereof contained in the drive current waveform of the spindle motor 3.
    Type: Application
    Filed: April 1, 2003
    Publication date: January 8, 2004
    Inventor: Masashi Kisaka
  • Publication number: 20030227706
    Abstract: The motor drive method is for a magnetic disk drive apparatus having a magnetic disk as an information recording medium, a magnetic head for recording/reproducing information to/from the magnetic disk, and a motor for driving the magnetic disk, the motor having a connection point connecting middle points in a multi-phase Y-connection and capable of realizing a unipolar drive method for successively exciting phases and a bipolar drive method for simultaneously exciting two adjacent phases, wherein the unipolar drive method is selected when the temperature in the magnetic disk drive apparatus is lower than a predetermined temperature and the bipolar drive method is selected when the temperature exceeds the predetermined temperature. The motor stationary rotation is assured by selecting the unipolar drive method or the bipolar drive method.
    Type: Application
    Filed: February 28, 2003
    Publication date: December 11, 2003
    Applicant: Hitachi, Ltd.
    Inventor: Osamu Beppu
  • Patent number: 6661626
    Abstract: In a tunnel junction sensor a free layer structure has a cobalt iron (Co90Fe10) layer and a half metallic iron oxide (Fe3O4) layer and a pinned layer structure has a cobalt iron (Co50Fe50) layer and a half metallic iron oxide (Fe3O4) layer. Each of the iron oxide layers interfaces a barrier layer which is compatible therewith. The thicknesses of the iron oxide (Fe3O4) layers are less than the thicknesses of the other layers of the free and pinned layer structures.
    Type: Grant
    Filed: March 20, 2001
    Date of Patent: December 9, 2003
    Assignee: International Business Machines Corporation
    Inventor: Hardayal Singh Gill
  • Patent number: 6643236
    Abstract: A method of elimination of interference created on CDR/W run-out motors on sledge servers, especially for the elimination of interference created by the run-out of the combination of CDR/W spindle motor on track-seeing servers, where a general evaluating device is provided linking the controller output of the data access module driven by the sledge server motor and the final track signal output, including a speed evaluating device and a run-out evaluating device that may have access to the run-out factor of the CDR/W motor and the CD in the data access module for evaluation of the elimination function of the speed and the run-out tolerance, so that the run-out evaluating device could emit run-out compensation signals for amplification by a relay amplifier and the spindle motor synchronized signal before a negative feedback calculation by playing the final output signal of the module, with access to a play control signal for the elimination of run-out to the CDR/W sledge server, so that the CD may be read, wri
    Type: Grant
    Filed: July 10, 2001
    Date of Patent: November 4, 2003
    Assignee: Behavior Tech Computer Corporation
    Inventor: Jen-Cheng Chiang
  • Patent number: 6643080
    Abstract: Method and apparatus for identifying a resonance by changing a spindle speed, which has the effect of changing a corresponding sampling rate and Nyquist frequency. The invention discriminates (1) between plausible frequencies of true resonance and/or (2) aliased resonance from non-aliased resonances. This is accomplished by monitoring whether and/or how a resonance shifts during this speed change. Methods of the present invention monitor resonances by deriving a resonance indicator such as an apparent frequency (below the Nyquist frequency), a gain or error magnitude (compared to a derived threshold at a calculated frequency of interest), or similar criteria tested by values conventionally illustrated on a Bode plot. The present invention further includes steps or structural features for configuring a controller to attenuate or similarly limit an unwanted frequency component of an actuator control signal. In this way, resonances in the actuator can be reduced, and servo speed and accuracy thereby enhanced.
    Type: Grant
    Filed: July 27, 2000
    Date of Patent: November 4, 2003
    Assignee: Seagate Technology LLC
    Inventors: Clyde Everett Goodner, III, Roy Lynn Wood, Lealon Ray McKenzie
  • Publication number: 20030193732
    Abstract: A disk array unit connected to a host unit to give information thereto and receive information therefrom. The disk unit includes a plurality of disk units for storing information transmitted from the host unit and a management information recording device, formed by utilizing information storage areas in the disk units, for causing information relating to a logical unit for storing information from the host unit to correspond to information relating to the units. The invention further includes a control unit, when there is no access from the host unit to the logical unit for a predetermined time, for determining the disk units corresponding to the logical unit based on information recorded in the management information recording device and performing power saving of power supply for the disk units.
    Type: Application
    Filed: April 14, 2003
    Publication date: October 16, 2003
    Inventors: Kazuo Hakamata, Kenichi Takamoto, Masaaki Kobayashi
  • Publication number: 20030193733
    Abstract: A disk array unit connected to a host unit to give information thereto and receive information therefrom. The disk unit includes a plurality of disk units for storing information transmitted from the host unit and a management information recording device, formed by utilizing information storage areas in the disk units, for causing information relating to a logical unit for storing information from the host unit to correspond to information relating to the units. The invention further includes a control unit, when there is no access from the host unit to the logical unit for a predetermined time, for determining the disk units corresponding to the logical unit based on information recorded in the management information recording device and performing power saving of power supply for the disk units.
    Type: Application
    Filed: April 14, 2003
    Publication date: October 16, 2003
    Inventors: Kazuo Hakamata, Kenichi Takamoto, Masaaki Kobayashi
  • Patent number: 6633450
    Abstract: A method and an apparatus for controlling a disk drive are contrived to reduce consumed electric power of a spindle motor of the disk drive while an operation continues. The disk drive has a disk storage medium, the spindle motor for rotating the disk storage medium, and a head for reading data on the disk storage medium. This control method comprises a first step of detecting a load of the spindle motor or a load capacity of a power source of the disk drive, and a second step of selecting any one of a first mode of revolving the spindle motor at a comparatively high speed and reading the data on the disk storage medium by the head, and a second mode of revolving the spindle motor at a comparatively low speed and reading the data on the disk storage medium by the head in accordance with a detected result of the first step.
    Type: Grant
    Filed: August 10, 1999
    Date of Patent: October 14, 2003
    Assignee: Fujitsu Limited
    Inventor: Hisashi Kaneko
  • Publication number: 20030184906
    Abstract: An apparatus and method for compensating for variation in sample rate in a disc drive having a rotating disc and a head that is positioned over the rotating disc is provided. The disc includes at least one track that has multiple consecutive sectors. A sample rate value between timing marks of each pair of consecutive sectors of the multiple consecutive sectors is computed to obtain a sequence of sample rate values. A sequence of timing error values is computed as a function of the sequence of sample rate values and a nominal sample rate value. Data related to the sequence of timing error values is utilized to compensate for variation in sample rate values.
    Type: Application
    Filed: June 27, 2002
    Publication date: October 2, 2003
    Inventors: Reed D. Hanson, Timothy F. Ellis, Dustin M. Cvancara, Nathaniel B. Wilson
  • Publication number: 20030184898
    Abstract: Method and apparatus for characterizing the flight characteristics of a read/write head. A disc is accelerated to a selected rotational velocity sufficient to aerodynamically support the head. The head is positioned over a portion of the disc non-accessible to customer data and a magnetoresistive element of the read/write is biased using a suitable voltage or current. A media noise landing signature obtained as the element transduces white noise from the surface identifies the head as a low-flying head.
    Type: Application
    Filed: September 25, 2002
    Publication date: October 2, 2003
    Applicant: Seagate Technology LLC
    Inventors: Housan Dakroub, Alfredo Gay Sam
  • Publication number: 20030184907
    Abstract: A method of overcoming stiction, at a head-to-disc interface, within a disc drive. The method comprises the operations of powering on the disc drive and initiating a motor spin-up routine. The motor spin-up routine involves a breakaway part, during which a spindle motor, carrying a disc in the disc drive, is driven with a spindle motor current at a first level sufficient to generate a motor torque greater than half of a maximum stiction force for a first time period in order to break stiction, and then driving the spindle motor with the spindle motor current at a second level, less than the first level after the first time period to rotate the disc. The breakaway part of the spin-up routine is followed by an acceleration part and then a normal disc rotation part during which nominal speed is maintained.
    Type: Application
    Filed: December 31, 2002
    Publication date: October 2, 2003
    Applicant: Seagate Technology LLC
    Inventors: Xinwei Li, Huan Tang, Jing Gui
  • Patent number: 6628470
    Abstract: A magnetic disk apparatus includes a magnetic head slider in which a magnetic head element is mounted, a magnetic disk to which recording and reproduction of data are made by means of the magnetic head element, a spindle motor which rotatably supports the magnetic disk, and a controller for controlling the rotational speed of the magnetic disk in each proper idle time that recording or reproduction is not made after completion of recording or reproduction to the magnetic disk by the magnetic head element until next recording or reproduction time.
    Type: Grant
    Filed: March 3, 2000
    Date of Patent: September 30, 2003
    Assignee: Hitachi, Ltd.
    Inventor: Takemichi Fujimori
  • Publication number: 20030179486
    Abstract: Provided are a method, system, and program for estimating coil resistance of a voice coil motor for an actuator assembly in a disk drive system. An estimation is made of a calibration coil resistance during a calibration operation. A determination is made of a distance moved during a seek operation. The determined distance and the calibration coil resistance are used to estimate a current coil resistance following the seek operation.
    Type: Application
    Filed: March 25, 2002
    Publication date: September 25, 2003
    Applicant: International Business Machines Corporation
    Inventors: Peter Kui Ho, Mantle Man-Hon Yu
  • Publication number: 20030174428
    Abstract: In the high-speed seek mode in which priority is given to making the seek operation faster, the CPU sets the driving voltage applied to a motor driver that drives both a spindle motor and voice coil motor to a first driving voltage. Furthermore, in the high-efficiency mode in which priority is given to reducing the power loss in the motor driver, the CPU sets the driving voltage applied to the motor driver to a second driving voltage lower than the first driving voltage.
    Type: Application
    Filed: January 17, 2003
    Publication date: September 18, 2003
    Applicant: KABUSHIKI KAISHA TOSHIBA
    Inventor: Nobuyuki Sakamoto
  • Patent number: 6617817
    Abstract: A power driver for driving a signal on a load using voltage-mode driver. A system processor generates commands indicating a programmed drive signal desired from the voltage-mode driver. A lead compensator determines a compensated command to compensate for an admittance function of the load. The compensated commands are coupled to the voltage-mode driver, such that the voltage-mode driver generates a voltage output based upon the compensated command.
    Type: Grant
    Filed: June 1, 2001
    Date of Patent: September 9, 2003
    Assignee: STMicroelectronics, Ltd.
    Inventor: John P. Hill
  • Patent number: 6614612
    Abstract: A disk drive having a motor and a velocity control loop, which includes a frequency detector and a filter. The filter includes a filter section and an accumulator. The filter is programmable in that filter coefficient(s) are dynamically received by the filter section. One embodiment of the filter section is an infinite impulse response filter. One embodiment of the filter is a digital integrated circuit. A method for compensating a control loop by infinite impulse response filtering and accumulating. The control loop may be a position, velocity, acceleration or force control loop. A programmable digital integrated circuit for compensating a velocity control loop having a filter section cascaded with an accumulator. The integrated circuit may include memory for storing filter coefficient(s) for the filter section, thereby not requiring external components.
    Type: Grant
    Filed: July 25, 2000
    Date of Patent: September 2, 2003
    Assignee: STMicroelectronics, Inc.
    Inventors: Paolo Menegoli, Ender Tunc Eroglu, Whitney Hui Li
  • Publication number: 20030156345
    Abstract: A data storage device including spindle power control to reduce power consumption. The spindle power control includes a read-write control mode and an idle control mode. In the read-write control mode, the spindle motor is energized to rotate a disc at a fill operating speed for read-write operations and in the idle control mode, spindle speed is reduced to provide an idle power mode. The idle power mode provides a desired or steady state fly height spindle speed so that the head glides above the disc surface during an idle period to reduce power consumption. In illustrated embodiments, the disc includes a dedicated glide zone and the head is positioned in the dedicated glide zone during the idle power mode.
    Type: Application
    Filed: June 27, 2002
    Publication date: August 21, 2003
    Inventors: Serge J. Fayeulle, Paul W. Smith
  • Patent number: 6603625
    Abstract: A multi-dimensional computer network is disclosed comprising a multi-dimensional network controller for interconnecting a plurality of computer devices, including a plurality of disk drives, communicating via a network protocol through a plurality of nodes, each node comprising more than two bi-directional ports for simultaneously transmitting data in multiple dimensions through the multi-dimensional computer network. At least one of the disk drives comprises a disk for storing data and an index mark, a spindle motor for rotating the disk, a head for reading the data and the index mark stored on the disk, an index mark detector for generating an index mark detect signal in response to the head reading the index mark, an interface for receiving a spindle sync signal from the multi-dimensional network controller through the network protocol, and a spindle synchronization circuit, responsive to the index mark detect signal, for synchronizing the rotation of the disk to the spindle sync signal.
    Type: Grant
    Filed: September 11, 2000
    Date of Patent: August 5, 2003
    Assignee: Western Digital Technologies, Inc.
    Inventors: Andrew D. Hospodor, Christopher L. Hamlin