Rotary Carrier Patents (Class 360/73.03)
  • Patent number: 7571279
    Abstract: A disk drive apparatus has a magnetic platter, a disk drive motor, and a disk drive controller. The disk drive controller is capable of storing data onto and retrieving data from the magnetic platter while the magnetic platter turns at a predefined maximum speed. The disk drive controller is configured to receive a command to access a storage location on the magnetic platter from an external storage controller, and direct the disk drive motor to increase rotational speed of the magnetic platter to the predefined maximum speed in response to the command. The disk drive controller is further configured to, prior to the magnetic platter reaching the predefined maximum speed, access the storage location on the magnetic platter in response to the command. Accordingly, early access to storage locations on the magnetic platter is not substantially hindered by the spin up process.
    Type: Grant
    Filed: September 28, 2006
    Date of Patent: August 4, 2009
    Assignee: EMC Corporation
    Inventors: Gilad Sade, Adi Ofer
  • Publication number: 20090190248
    Abstract: Techniques are provided herein for reducing vibrations in various modes of a dynamic system. One such technique comprises incorporating vibration limiting and sensitivity constraints into a partial fraction expansion equation model of the system so as to reduce vibrations to specific levels. Another technique comprises shaping a command determined using the partial fraction expansion equation model to produce a desired output. The entire command may be shaped or only selected portions thereof which produce vibrations. Another technique involves commanding in current to produce saturation in voltage. By doing this it is possible to command voltage switches. The times at which the switches occur can be set to reduce system vibrations. Other techniques are also provided. These include varying transient portions at the beginning, middle and/or end of a move and using Posicast inputs, among others.
    Type: Application
    Filed: September 23, 2008
    Publication date: July 30, 2009
    Inventors: Neil Singer, Mark Tanquary, Kenneth Pasch
  • Patent number: 7567401
    Abstract: A method and apparatus for controlling a rotation of a motor in a disk drive. The method includes: performing spin-up when the disk drive is operating and determining whether a disk rotation speed is less than predetermined target constant revolutions per minute (RPM); rotating a disk at predetermined low RPM when determining that the disk drive is at a low temperature and changing a rotation mode to a low-speed rotation mode if it is determined that the disk rotation speed is less than the predetermined target constant RPM; and spinning up the disk to the target constant RPM when determining that the temperature of the disk drive has increased and changing the rotation mode to a high-speed rotation mode if a disk rotation driving current decreases below a predetermined reference current value while the disk is rotating at the low RPM.
    Type: Grant
    Filed: September 11, 2006
    Date of Patent: July 28, 2009
    Assignee: Samsung Electronics Co., Ltd.
    Inventors: Hong-kwon Lee, Sang-chul Shin
  • Patent number: 7561364
    Abstract: A method and an apparatus to control a disc drive, and more particularly, a method and an apparatus to control a disc drive using a counter-electromotive force, prevents collision and malfunction of a transducer and a disc by determining external vibrations and magnitude of a shock without installing an additional shock sensor in the disc drive. The method of controlling the disc drive using a counter-electromotive force includes detecting a voltage applied to a spindle motor during a predetermined mode, performing an operation of a value of the counter-electromotive force using the detected spindle motor voltage comparing the value of the counter-electromotive force operated with a predetermined threshold, and when the value of the counter-electromotive force is equal to or larger than the predetermined threshold, controlling a voice coil motor and a spindle motor so that a current mode is stopped and a parking or unloading mode is executed.
    Type: Grant
    Filed: May 23, 2006
    Date of Patent: July 14, 2009
    Assignee: Samsung Electronics Co., Ltd.
    Inventor: Sang-chul Shin
  • Publication number: 20090168221
    Abstract: A method according to one embodiment comprises detecting a change in a rotational velocity of a magnetic disk or a spindle coupled to the magnetic disk, the change being caused by head-disk contact. A method for detecting head-disk contact according to another embodiment comprises measuring a rotational velocity of a magnetic disk or a spindle coupled to the magnetic disk; detecting a change in the rotational velocity, the change being caused by head-disk contact; and correlating the change in rotational velocity with the head-disk contact.
    Type: Application
    Filed: December 28, 2007
    Publication date: July 2, 2009
    Inventors: Peter Michael Baumgart, Charles Raymond Davis, Gary Allan Herbst, Bernhard E. Knigge, Charles Mathew Mate, Bruce Alexander Wilson
  • Patent number: 7535666
    Abstract: A rotation speed of a disk-type storage medium is suitably controlled in order to save power and to reduce noise in a disk-type storage medium driving apparatus provided with one or more communication interfaces. A disk-type storage medium driving apparatus that can switch rotation speed of a disk-type storage medium, to drive the disk-type storage medium, includes one or more communication interface units, which perform data transfer to and from peripheral devices; and a control unit that judges necessity of switching a rotation speed of the disk-type storage medium when there occurs a data transfer request through one of the communication interface units.
    Type: Grant
    Filed: July 24, 2007
    Date of Patent: May 19, 2009
    Assignee: Hitachi, Ltd.
    Inventors: Yukie Hiratsuka, Yukihide Inagaki
  • Patent number: 7531975
    Abstract: A spindle/voice coil motor (VCM) driver includes a clock management module that receives a system clock signal and a second clock signal, and that selects one of the system clock signal or the second clock signal as a selected clock signal. A reference generating module generates a reference signal. A ramp generating module receives the selected clock signal and generates a ramp signal. A pulse width modulation (PWM) module receives the reference signal and the ramp signal and outputs a first PWM driver signal based thereon.
    Type: Grant
    Filed: April 12, 2005
    Date of Patent: May 12, 2009
    Assignee: Marvell International Ltd.
    Inventors: Sakti P. Rana, Foo Leng Leong, Cheng Yong Teoh
  • Patent number: 7518817
    Abstract: A disk drive having reduced electromagnetic emission quasi-peaks is provided. The repetition rate of servo blocks or data is reduced, spread or otherwise altered. In one embodiment, the number of data zones is increased to achieve an emissions reduction goal. In one embodiment, the disk drive is configured to effectively have one track per zone. In one embodiment, the rotation rate of the disk is varied or the effective data bit density, as detected by the read/write head, is otherwise varied. In one embodiment, servo-sectors are intentionally positioned to vary the length, along the track, of inter-servo intervals.
    Type: Grant
    Filed: July 10, 2006
    Date of Patent: April 14, 2009
    Assignee: Maxtor Corporation
    Inventors: Arun Balakrishnan, John VanLaanen, Leo Lopez, John Shaw, Bruce D. Buch, Claud L. Blevins
  • Patent number: 7512865
    Abstract: A method for controlling read velocity in a disk device is provided. When reading data on the disc, the method first reads each SYNC of blocks to form an ECC code, read data to decode, and checks and corrects decoded data to generate decoded errors. The type of decoded errors are classified and counted to form reference parameters of a rule base. A fuzzy engine checks if the counting number exceeds the threshold of the parameter, and executes the operation of the rule to control read velocity and enhance the data transfer rate in the disk device.
    Type: Grant
    Filed: March 31, 2006
    Date of Patent: March 31, 2009
    Assignee: Quanta Storage Inc.
    Inventor: Chao-Pei Lu
  • Patent number: 7511911
    Abstract: A storage system capable of reducing the start-up time of disk drives is provided. If a power source monitor circuit itself is normal (S93), the power source monitor circuit reads a detection signal from a detection circuit, and checks power sources (S94). If the power sources are normal (S95), all disks are spun up (S96). When the spin-up of all disks is completed (S98), processing is completed. If either of two power sources fails (S95), the power source monitor circuit reports the fact to a host control logical part (S99). The power source monitor circuit clears its internal counter to zero (S100) and issues a drive command to HDDs (S101). When the spin-up of all disks is completed (S103), processing is completed. If there is a disk which has not yet been spun up, the power source monitor circuit sets the internal counter to n+1 (S104) and returns to Step S101.
    Type: Grant
    Filed: August 30, 2006
    Date of Patent: March 31, 2009
    Assignee: Hitachi, Ltd.
    Inventors: Hiroshi Suzuki, Hiromi Matsushige, Masato Ogawa
  • Patent number: 7508614
    Abstract: A drive for data storage includes a first component and a second component movable with respect to the first component. The drive also includes a first sensor and a second sensor. The first sensor is in connection with the first component and is configured to detect movement of the first component. The second sensor is in connection with the second component and is configured to detect movement of the second component.
    Type: Grant
    Filed: April 9, 2007
    Date of Patent: March 24, 2009
    Assignee: Hewlett-Packard Development Company, L.P.
    Inventors: Ratnesh K. Sharma, Chandrakant D. Patel
  • Publication number: 20090015960
    Abstract: Embodiments of the invention increase the convenience of a magnetic disk drive for portable use by shortening a period of time required to record a large amount of data, and by increasing the reproduction time, in the magnetic disk drive. In one embodiment, an area between servo data parts is interpolated by servo data parts, each of which stores a burst signal, so that the allocation density of a burst signal is made k times. At the time of write operation in which data is written, only the servo data parts are made use of to perform the servo control while a disk is driven at high rotational speed so as to reduce the recording time. At the time of read operation in which data is reproduced, the servo data parts are made use of to ensure the required precision of the servo control at low rotational speed that is 1/k of the rotational speed at the time of write operation. The reproduction at low rotational speed enables the reduction in power consumption.
    Type: Application
    Filed: June 30, 2008
    Publication date: January 15, 2009
    Applicant: Hitachi Global Storage Technologies Netherlands B.V.
    Inventors: Naoki Satoh, Yoshiteru Ishida, Yoshiju Watanabe, Terumi Takashi
  • Patent number: 7474490
    Abstract: Embodiments in accordance with the present invention provide a disk drive that ensures quieter rotational acceleration of a recording disk. Certain embodiments relate to a hard disk drive that detects the vibration of an enclosure by monitoring, via a driver, a counter electromotive voltage generated in a voice coil motor. If the hard disk drive detects a predetermined level of vibration or higher in the enclosure, it switches the status of a drive signal applied to a spindle motor so as to reduce the current level or smooth the waveform. This ensures reduced vibration of the enclosure.
    Type: Grant
    Filed: April 26, 2007
    Date of Patent: January 6, 2009
    Assignee: Hitachi Global Storage Technologies Netherlands B.V.
    Inventors: Yukiko Hayashi, Isao Yoneda, Gaku Ikedo, Nobuhisa Koide, Yuhji Amari
  • Patent number: 7466095
    Abstract: A system and method for controlling an actuator includes a control module that communicates with a plurality of switching devices to generate current through a voice coil motor during a first time period so that an actuator arm rotates in a first rotational direction in response to the current. The control module controls the switching devices to discharge the current from the voice coil motor during a second time period less than the first time period so that the first rotational direction of the actuator arm is maintained after discharging the current. The control module further includes a back electromagnetic force (bemf) module for determining a bemf voltage after controlling the switching devices to discharge the current, and an actuator arm speed control module for determining an actuator arm speed in response to the bemf voltage.
    Type: Grant
    Filed: June 19, 2006
    Date of Patent: December 16, 2008
    Assignee: Marvell International Ltd.
    Inventor: Siew Yong Chui
  • Patent number: 7461271
    Abstract: An optical recording apparatus with a small form factor optical drive for driving an optical record carrier is operable in different accessing modes having different data rates depending on the power mode of the recording apparatus. A Switch is provided in the recording apparatus for switching a controller for accessing the optical record carrier for reading data from or recording data to the optical record carrier. A first accessing mode has a low data rate and is used in a low power mode, while a second accessing mode has a high data rate and is used or allowed to be used in a high power mode.
    Type: Grant
    Filed: November 26, 2003
    Date of Patent: December 2, 2008
    Assignee: Koninklijke Philips Electronics N.V.
    Inventors: Frank Cornelis Penning, Michael Adrianus Henricus Van Der AA, Bart Van Rompaey, Bart Michiel De Boer, Steven Broeils Luitjens
  • Patent number: 7457073
    Abstract: Embodiments in accordance with the present invention allow a magnetic disk drive to achieve noise reduction and low power consumption through rotation at a low speed and a high transfer rate through rotation at a high speed while allowing reliability to be maintained and achieving an improved recording density. An embodiment of a magnetic disk drive in accordance with the present invention includes, a magnetic disk medium driven at a plurality of rotational speeds, a magnetic head for recording and reproducing data in and from the magnetic disk medium, a heater for controlling a flying height of the magnetic head, and a control unit for controlling the current to the heater, and in that the control unit controls the current to the heater. The control unit controls the current to the heater according to the plurality of rotational speeds.
    Type: Grant
    Filed: February 14, 2007
    Date of Patent: November 25, 2008
    Assignee: Hitachi Global Storage Technologies Netherlands B.V.
    Inventors: Masayuki Kurita, Yukie Hiratsuka, Mikio Tokuyama, Hideaki Tanaka
  • Publication number: 20080278841
    Abstract: Various embodiments relate to selectively inhibiting output from a transducer in response to the rate of change of acceleration that is experienced by the transducer. The rate of change of an acceleration signal, which is indicative of transducer's acceleration, is detected. Output of a signal through the transducer is selectively inhibited in response to the detected rate of change of the acceleration signal. A related apparatus can include a circuit that detects the rate of change of an acceleration signal and generates a transducer output inhibit signal in response to the detected rate of change of the acceleration signal. Another related apparatus can include a transducer, an accelerometer, and a circuit. The transducer writes data on a recordable media. The accelerometer generates an acceleration signal that is indicative of transducer vibration. The circuit selectively inhibits writing of data through the transducer in response to a rate of change of the acceleration signal.
    Type: Application
    Filed: October 31, 2007
    Publication date: November 13, 2008
    Inventors: Lealon Ray McKenzie, Steve M. Gaub, Sandeep D. Sequeira, Matthew McLeod Chadsey
  • Patent number: 7430088
    Abstract: A retracting method of compensating for a time for parking and unloading with an additional floating force obtained by additionally operating a spindle motor for a predetermined period after a retract operation is started, a hard disk drive (HDD) adopting the method, and a computer readable recording medium having a program for performing the method. The retracting method of the hard disk drive to retract a head to a retract area in response to detection of a retract condition includes driving the spindle motor at least for a predetermined period at the beginning of a retract operation to rotate a disk. The spindle motor is additionally driven for the predetermined period after the retract operation is started such that an additional floating force can be obtained, and thus, a time for parking and unloading is compensated for, and a stable retract operation is performed.
    Type: Grant
    Filed: November 6, 2006
    Date of Patent: September 30, 2008
    Assignee: Samsung Electronics Co., Ltd.
    Inventors: Sang-hun Lee, Jae-deog Cho
  • Patent number: 7430087
    Abstract: A velocity calculator performs high-order calculations of servo frame velocities of a storage media, particularly tape and disk. The velocity calculator employs a servo frame indexing module for generating a first-order preceding servo frame velocity signal indicative of a first-order calculation of a preceding servo frame velocity including a first-order preceding servo frame error term based on first-order current servo frame velocity signal indicative of a first-order calculation of a current servo frame velocity including a first-order current servo frame error term. The velocity calculator further employs a velocity estimating module for generating a higher-order current servo frame velocity signal indicative of a second or higher order velocity calculation of the current servo frame velocity including a higher-order current servo frame error term based on the first-order preceding servo frame velocity signal and the first-order current servo frame velocity signal.
    Type: Grant
    Filed: September 5, 2006
    Date of Patent: September 30, 2008
    Assignee: International Business Machines Corporation
    Inventors: Allen K. Bates, Nils Haustein, Craig A. Klein, Daniel J. Winarski
  • Patent number: 7426620
    Abstract: An apparatus and a method for memory access of sharing the address and the data buses used in multi-media player, comprising at least one SDRAM, storing the large data and as a buffer in high speed; at least one flash memory, storing the programs, the user's defaults and firmware, wherein the address and data pins of the SDRAM and the flash memory are coupled with a same bus respectively, and SDRAM and flash memory are not accessed at the same time; a memory interface, connecting the address bus and data bus shared by the SDRAM and flash memory. The memory interface further comprises an arbiter, deciding which one of the access requests is executed according to the request priority. It is noticed that only one of the SDRAM or the flash memory can be accessed at one time.
    Type: Grant
    Filed: August 25, 2004
    Date of Patent: September 16, 2008
    Assignee: VIA Technologies, Inc.
    Inventor: Ting-Kun Yeh
  • Publication number: 20080218894
    Abstract: It is an object of the present invention to make it possible to suppress, to the maximum extent possible, deformation of the recording medium caused by clamping in a spindle motor having a medium-carrying surface. The spindle motor comprises a shaft, a rotor, and a medium-carrying surface. The rotor is disposed on the outer peripheral side of the shaft, and rotates about the shaft. The medium-carrying surface is disposed on the rotor, and carries a circular-disk-form recording medium. The recording medium is pressed and fastened to the medium-carrying surface by a clamping member. The clamping member is a member that presses the recording medium against a medium-carrying surface. The average value Lpave of the widths Lpk of the profile peaks in the mean line for the primary profile of the medium-carrying surface in the radial direction is smaller than the average value Lvave of the widths Lvk of the profile valleys.
    Type: Application
    Filed: February 27, 2008
    Publication date: September 11, 2008
    Inventor: Eiji TOMITA
  • Patent number: 7408733
    Abstract: Embodiments of the invention increase the convenience of a magnetic disk drive for portable use by shortening a period of time required to record a large amount of data, and by increasing the reproduction time, in the magnetic disk drive. In one embodiment, an area between servo data parts is interpolated by servo data parts, each of which stores a burst signal, so that the allocation density of a burst signal is made k times. At the time of write operation in which data is written, only the servo data parts are made use of to perform the servo control while a disk is driven at high rotational speed so as to reduce the recording time. At the time of read operation in which data is reproduced, the servo data parts are made use of to ensure the required precision of the servo control at low rotational speed that is 1/k of the rotational speed at the time of write operation. The reproduction at low rotational speed enables the reduction in power consumption.
    Type: Grant
    Filed: April 7, 2006
    Date of Patent: August 5, 2008
    Assignee: Hitachi Global Storage Technologies Netherlands B.V.
    Inventors: Naoki Satoh, Yoshiteru Ishida, Yoshiju Watanabe, Terumi Takashi
  • Patent number: 7400466
    Abstract: A method and apparatus for driving a spindle motor using adaptive feedforward control. The method includes: detecting a temperature of a drive; calculating a feedforward value corresponding to the detected temperature; and generating a first control signal that is a drive current according to a calculated feedforward value and applying the generated first control signal to the spindle motor.
    Type: Grant
    Filed: August 25, 2006
    Date of Patent: July 15, 2008
    Assignee: Samsung Electronics Co., Ltd.
    Inventors: Kang-seok Lee, Kyoung-whan Oh, Cheol-hoon Park
  • Publication number: 20080144208
    Abstract: A disk drive having a single drive motor and multiple platters that incorporates two discrete data paths, actuators and heads to the disk platters. Utilizing the economy of very large capacity disk platters, two or more disk drives can be created within a single physical enclosure. These two disks will be share many common parts such as the drive enclosure and spindle motor, but will have the performance and appearance to the system as two or more independent disks. Instead of having one actuator arm, the virtual disks will have two or more actuator arms and two or more sets of digital electronics. The storage on all the platters is divided up among the actuators so that no storage location is shared, but all the actuators will operate concurrently. Each actuator will have exclusive use of a subset of the data storage. Disks normally only have one actuator connected to multiple heads, at least one per surface, which only allow a single data seek and data transfer at a time.
    Type: Application
    Filed: December 19, 2006
    Publication date: June 19, 2008
    Inventors: William Ward, P. Keith Muller
  • Patent number: 7369345
    Abstract: A system provided for protecting a disk drive from impact damages. More specifically, a disk drive is provided that includes an accelerometer interconnected to a printed circuit board that detects free fall of the disk drive. In addition, the velocity of spinning disks of the disk drive is also monitored to assess changes in velocity thereof that may indicate the presence of a tumbling condition. Furthermore, the change in acceleration measured by the accelerometer is monitored to prevent false indications of free fall due to common vibrations. Thus an enhanced system is provided that protects disk drives from the effect of free falls under a wide variety of conditions and allowing for drops from shorter distances to be identified.
    Type: Grant
    Filed: December 2, 2005
    Date of Patent: May 6, 2008
    Assignee: Maxtor Corporation
    Inventors: Yunfeng Li, Erhard Schreck, Wei Guo, Tim Glassburn, Mark Heimbaugh, William Flynn, Oliver Northrup, John E. Scura, Lin Guo, Xiaokun Chew
  • Patent number: 7369344
    Abstract: A method for compensating an offset of a disk drive which is accomplished by recording actual spin jitter while performing track following, extracting a DC component from a recorded actual spin jitter, and compensating for an offset of a spindle speed based on an extracted DC component.
    Type: Grant
    Filed: June 2, 2006
    Date of Patent: May 6, 2008
    Assignee: Samsung Electronics Co., Ltd.
    Inventor: Seung Chul Park
  • Publication number: 20080062555
    Abstract: Embodiments of the present invention provide a magnetic disk device including a spindle motor using a fluid dynamic bearing, which can send back READY within a period requested by a host system at the time of starting a magnetic disk device under low temperature and low supply voltage conditions without particular heating means. According to one embodiment, the magnetic disk device sets a waiting time in a period from when a spindle motor reaches a rated speed until when an HSA is loaded to a magnetic disk at the time of starting under low temperature and low supply voltage conditions within such a range that the timeout of the host does not occur, and the spindle motor itself is heated by rotation of the spindle motor in the waiting time to lower viscosity of the lubrication fluid to ensure sufficient voltage margin for an SPM driver.
    Type: Application
    Filed: September 7, 2007
    Publication date: March 13, 2008
    Applicant: Hitachi Global Storage Technologies Netherlands B.V.
    Inventors: Iwao Oshimi, Gaku Ikedo, Nobuhisa Koide, Jiro Abe
  • Publication number: 20080055764
    Abstract: A motor stator includes a stator core stack having a core back and a plurality of teeth extending from the core back in a radial direction of the core back. The motor stator also includes winding wires wound around the teeth and having no bonding layer. Only winding wires of the first and third phases are wound to prevent loosening thereof.
    Type: Application
    Filed: August 28, 2007
    Publication date: March 6, 2008
    Applicant: NIDEC CORPORATION
    Inventors: Hiromasa FUJII, Wataru YAMAUCHI
  • Patent number: 7330326
    Abstract: An error correction circuit for determining an error in rotational speed of a recordable disk of a disk drive includes a sinusoidal error calculation portion adapted to generate a true oscillation error signal, and a summation portion adapted to combine the true oscillation error with a spindle error signal to generate a total error signal. The sinusoidal error calculation portion is adapted to generate a new true oscillation error based on the total error signal.
    Type: Grant
    Filed: March 9, 2004
    Date of Patent: February 12, 2008
    Assignee: Hewlett-Packard Development Company, L.P.
    Inventor: Darwin Mitchel Hanks
  • Publication number: 20080019246
    Abstract: An integrated circuit (IC) for controlling a rotating data storage device comprises a drive module that is implemented by the integrated circuit and that at least one of processes data, stores data and controls operation of the rotating storage device. An audio monitoring module is implemented by the integrated circuit, communicates with the drive module and analyzes audio signals that are based on noise generated by the rotating storage device during operation.
    Type: Application
    Filed: January 11, 2007
    Publication date: January 24, 2008
    Inventor: Sehat Sutardja
  • Publication number: 20080019245
    Abstract: A control system for a rotating data storage device, comprises a drive printed circuit board (PCB). A drive module is arranged on the drive PCB and at least one of processes data, stores data and controls operation of the rotating storage device. An audio monitoring module communicates with the drive module and analyzes audio signals that are based on noise generated by the rotating storage device during operation.
    Type: Application
    Filed: November 1, 2006
    Publication date: January 24, 2008
    Inventor: Sehat Sutardja
  • Publication number: 20070268607
    Abstract: A loading/unloading type magnetic disk unit includes a magnetic disk that is rotated or driven by a motor, and a head slider bearing a magnetic head and being movable above the magnetic disk owing to a driving mechanism. Herein, at least one projection made of a highly conductive material is formed on the surface of the head slider opposed to the magnetic disk. When the magnetic disk unit is in operation, conduction to the spindle motor is discontinued after the elapse of a predetermined time. Thus, the height by which the head slider floats is decreased so that the projections come into contact with the magnetic disk. Consequently, a charge on the magnetic disk escapes through the housing of the magnetic disk unit via the head slider. Thus, when the loading/unloading type magnetic disk unit is in operation, a charge on the magnetic disk can be removed.
    Type: Application
    Filed: August 22, 2006
    Publication date: November 22, 2007
    Inventor: Tohru Iwamoto
  • Publication number: 20070253089
    Abstract: Embodiments in accordance with the present invention provide a disk drive that ensures quieter rotational acceleration of a recording disk. Certain embodiments relate to a hard disk drive that detects the vibration of an enclosure by monitoring, via a driver, a counter electromotive voltage generated in a voice coil motor. If the hard disk drive detects a predetermined level of vibration or higher in the enclosure, it switches the status of a drive signal applied to a spindle motor so as to reduce the current level or smooth the waveform. This ensures reduced vibration of the enclosure.
    Type: Application
    Filed: April 26, 2007
    Publication date: November 1, 2007
    Applicant: Hitachi Global Storage Technologies Inc.
    Inventors: Yukiko Hayashi, Isao Yoneda, Gaku Ikedo, Nobuhisa Koide, Yuhji Amari
  • Patent number: 7289288
    Abstract: A disk drive is disclosed having hybrid spindle speed control. The disk drive includes a disk having a plurality of servo wedges, and a spindle motor for rotating the disk at an operating speed. The spindle motor generates a back electromotive force (BEMF) voltage. In operation, the disk rotation is maintained at the operating speed during a track following operation by updating, in a wedge spindle speed control mode, the spindle control current in response to a wedge speed error. Before executing a high-speed seek, the disk drive is switched to a BEMF spindle speed control mode, and the disk rotation is maintained at the operating speed during the high speed seek by updating the spindle control current in response to a BEMF speed error signal generated based on the BEMF voltage. During a seek-settle time, the disk drive is switched back to the wedge spindle speed control mode.
    Type: Grant
    Filed: March 23, 2006
    Date of Patent: October 30, 2007
    Assignee: Western Digital Technologies, Inc.
    Inventor: Kuang-Yang Tu
  • Patent number: 7289287
    Abstract: In an apparatus for recording and/or reproducing information, which reproduces servo information being recorded on a medium and conducts a tracking operation based on the servo information, a power save part conducts a power save operation by reducing an operation clock frequency in accordance with a predetermined process during a tracking operation, during a seek operation, and/or during spindle motor startup.
    Type: Grant
    Filed: October 22, 2002
    Date of Patent: October 30, 2007
    Assignee: Fujitsu Limited
    Inventors: Kouhei Takamatsu, Tomoaki Saito, Kenji Itou, Isamu Tomita, Hiroshi Tsurumi
  • Patent number: 7280935
    Abstract: A system for precisely determining a position with resolution on the order of nanometers or sub-nanometers is described. In particular, a system is described that utilizes a first and a second sensor assembly to determine a position of a movable element over a distance many times the capable range of operation of either of the individual sensor assemblies. The two sensor assemblies leap-frog one another in an incremental fashion to ensure that at least one of the sensor assemblies is always within it operational range. Positional signals generated by one of the sensor assemblies can be used to calibrate the other sensor assembly, following an adjustment of the other sensor assembly. The described invention may be implemented in an optical storage disk mastering system to determine the position of mastering optics as the mastering optics translate over the surface of a storage master disk.
    Type: Grant
    Filed: September 2, 2004
    Date of Patent: October 9, 2007
    Assignee: Imation Corp.
    Inventor: Jathan D. Edwards
  • Patent number: 7262929
    Abstract: The invention relates to a device comprising a disk drive 1 for rotating a disk memory and at least one interface enabling a data flow between a rotating disk memory and at least one other module 10, 12. In order to enable a comfortable use of such a device, it is proposed that the device further comprises means 2 for setting the rotation speed of the disk drive 1 based on an indication of the data rate supported by an interface of the device, which interface is currently to be employed for enabling a data flow between the rotating disk memory and at least one other module 10, 12. The invention relates equally to a method setting the rotation speed of a disk drive 1 according to the capabilities of an interface enabling a data flow between a disk memory rotated by the disk drive 1 and another module 10, 12.
    Type: Grant
    Filed: April 15, 2003
    Date of Patent: August 28, 2007
    Assignee: Nokia Corporation
    Inventors: Venkatesh Vadde, Jakke Mäkelä, Jukka-Pekka Vihmalo
  • Patent number: 7253581
    Abstract: Embodiments of the invention provide a way to accurately detect the position of a spindle motor. In a spindle motor startup process according to one embodiment, a parameter setup section acquires from a parameter table a sense time value corresponding to an input voltage that is acquired from an ADC. The parameter setup section sets the sense time value in a register. A position determination section, which is within an SPM driver, performs an induced voltage detection process for rotor position detection purposes during the time corresponding to the sense time value that is set in the register. Even when the input voltage is decreased, rotor position detection can be properly achieved by changing the sense time value in accordance with a change in the input voltage.
    Type: Grant
    Filed: January 6, 2005
    Date of Patent: August 7, 2007
    Assignee: Hitachi Global Storage Technologies Netherlands B.V.
    Inventors: Nobuhisa Koide, Yukiko Hayashi, Shougo Shimada, Gaku Ikedo
  • Patent number: 7253582
    Abstract: A disk drive is disclosed comprising a spindle motor having a plurality of windings including at least a first winding, a second winding, and a third winding. During a spin-up operation, a voltage is applied to the first winding and a first rise time is measured for current flowing through the first winding to reach a predetermined threshold. A voltage is applied to the second winding and a second rise time is measured for current flowing through the second winding to reach a predetermined threshold. A voltage is applied to the third winding and a third rise time is measured for current flowing through the third winding to reach a predetermined threshold. A difference is computed in response to the first rise time, the second rise time, and the third rise time, and an angular position of the spindle motor is estimated by computing an arctangent in response to the difference.
    Type: Grant
    Filed: May 28, 2004
    Date of Patent: August 7, 2007
    Assignee: Western Digital Technologies, Inc.
    Inventors: Jianghong Ding, Chuanwen Ji, David D. Nguyen
  • Patent number: 7251544
    Abstract: A storage system comprises a first plurality of storage cartridges along an accessible side of a path, a second plurality of storage cartridges along a non-accessible side of the path, and a transport device to move the first and second plurality of magazines around the path. The storage system further comprises a controller that determines the location of a particular cartridge and operates the transport device to move the particular cartridge to the accessible side of the path to gain access to the particular cartridge. The controller can also be configured to re-position a movable accessor device along the accessible side of the path to access the particular cartridge. The ability to move the cartridges on both sides of the path can at least double the accessible storage capacity of the system.
    Type: Grant
    Filed: July 1, 2003
    Date of Patent: July 31, 2007
    Assignee: Hewlett-Packard Development Company, L.P.
    Inventor: Leslie G. Christie, Jr.
  • Publication number: 20070159709
    Abstract: Provided are an apparatus and method for controlling a motor which compensates for a mechanical tolerance of the motor in a case where a feedback sampling frequency increases in order to more precisely control a brushless DC motor. The apparatus for compensating the mechanical tolerance of the brushless DC motor includes: a speed controller calculating a speed error that is a difference between a motor speed measured in control sections and a reference speed using a back electromotive force generated by the motor, and generating a motor control input signal using the speed error of the control section; a moving average calculator calculating a moving average value of the motor control input signals in a predetermined moving average section including recently generated motor control input signal whenever the motor control input signals are generated; and a motor driver generating an electric current for driving the motor corresponding to the moving average value.
    Type: Application
    Filed: January 8, 2007
    Publication date: July 12, 2007
    Inventors: Nam-guk Kim, Kyoung-whan Oh
  • Patent number: 7233454
    Abstract: A floppy disk control circuit enables a floppy disk apparatus to operate at high speed while current consumption is suppressed to no more than 500 mA, i.e. the maximum allowed current of an apparatus using a USB interface. The floppy disk control circuit outputs a reference clock to a spindle motor drive circuit that drives the spindle motor in accordance with the reference clock to rotate a floppy disk. The floppy disk control circuit outputs a slow reference clock for a low rotational speed corresponding to the maximum allowed current at the commencement of the start-up of rotation of the floppy disk and outputs a fast reference clock for a high rotational speed after lapse of a predetermined time from the commencement of the start-up of rotation.
    Type: Grant
    Filed: March 9, 2005
    Date of Patent: June 19, 2007
    Assignee: Rohm Co., Ltd.
    Inventor: Seiji Takenaka
  • Patent number: 7230787
    Abstract: An apparatus that controls a head that reads data from and writes data to a recording medium of which a spinning speed is controlled based on a clock signal includes a clock-error detecting unit that detects an error in the clock signal, and a head-retraction control unit that controls the head in such a way that the head is safely retracted when the error is detected by the clock-error detecting unit.
    Type: Grant
    Filed: October 13, 2004
    Date of Patent: June 12, 2007
    Assignee: Fujitsu Limited
    Inventor: Toshifumi Hatagami
  • Patent number: 7230785
    Abstract: A drive control device of a DC brushless multi-phase motor performs the speed control of the motor in place microprocessor, the burden on the microprocessor is relieved. The drive control device detects a zero crossing point of the back electromotive force in the non-energizing phase to perform the energizing switching to the coils by the PLL control, and includes a current detection circuit that detects currents flowing through the coils to perform the speed control of the motor based on the detected currents. The drive control device also, compares outputs from speed error detection circuit with outputs from the current detection circuit to determine the currents to be made to flow through the coils, and thereby controls the current output circuit.
    Type: Grant
    Filed: August 25, 2005
    Date of Patent: June 12, 2007
    Assignee: Renesas Technology Corp.
    Inventors: Kichiya Itagaki, Hiroshi Sato, Kenji Yoshida
  • Patent number: 7187517
    Abstract: A magnetic brake to prevent rotation of the spindle motor and disk(s). The magnetic brake includes two magnets, one attached to the spindle, clamp, disk, or motor, and the other magnet is coupled to the drive housing or to a movable member. Before the drive is installed in a computer, storage array, etc., the magnet coupled to the housing is removed externally, or the movable member is moved to free rotation of the spindle motor and disk(s). The movable member can also be caused to move automatically when a cable is attached to the drive. An alternate embodiment wraps a wire coil around one of the magnets to counter its magnetism upon energization, freeing the spindle motor and disk(s).
    Type: Grant
    Filed: December 19, 2003
    Date of Patent: March 6, 2007
    Assignee: Hitachi Global Storage Technologies Netherlands B.V.
    Inventors: Norbert A. Feliss, Donald Ray Gillis, Reinhard F. Wolter
  • Patent number: 7177105
    Abstract: An apparatus, method, and system for writing data to a hard disk drive synchronous with an apparent disk speed. The apparatus, method, and system has a phase-locked loop (PLL) to generate am output clock signal, wherein a clock interpolator responsive to phase rotation control is in the PLL feedback loop. The phase rotation control is proportional to the apparent disk speed, and the PLL output clock signal is also proportional to the apparent disk speed. A second clock interpolator further modifies the PLL output clock signal to provide pre-compensation control.
    Type: Grant
    Filed: May 15, 2006
    Date of Patent: February 13, 2007
    Assignee: Marvell International Ltd.
    Inventor: Pantas Sutardja
  • Patent number: 7158328
    Abstract: A disc drive having a multi-phase acceleration procedure is disclosed. The multi-phase acceleration procedure accelerates a data storage disc in the disc drive from an initial rotational velocity to a final rotational velocity. As the disc reaches the final rotational velocity, a read/write head operable to access data on the disc is moved by a servo control system from a landing zone to a data region on the disc. An air bearing between a slider of the read/write head and the surface of the disc is created due to the final rotational velocity of the spinning disc. The read/write head may also be moved from the landing zone as the disc reaches an early exit rotational velocity. As such, the multi-phase acceleration procedure continues accelerating the disc until the final rotational velocity to guarantee that the air bearing is maintained between the head and the disc.
    Type: Grant
    Filed: October 17, 2001
    Date of Patent: January 2, 2007
    Assignee: Seagate Technology LLC
    Inventor: Serge Jacques Fayeulle
  • Patent number: 7158329
    Abstract: A disk drive is disclosed comprising a disk, a head actuated over the disk, and a spindle motor for rotating the disk, the spindle motor comprising a plurality of windings. Disk control circuitry executes a spin-down operation of the spindle motor by estimating an angular position of the spindle motor by applying a voltage to at least one of the windings and evaluating a rise time of current flowing through the winding. The windings are commutated in response to the estimated angular position, and a driving current is applied to the windings to brake the spindle motor.
    Type: Grant
    Filed: May 23, 2005
    Date of Patent: January 2, 2007
    Assignee: Western Digital Technologies, Inc.
    Inventor: Robert P. Ryan
  • Patent number: 7158332
    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: Grant
    Filed: November 21, 2005
    Date of Patent: January 2, 2007
    Assignees: Renesas Technology Corp., Hitachi ULSI Systems Co., Ltd.
    Inventor: Yasuhiko Kokami
  • Patent number: 7136247
    Abstract: A method and program product supporting adjusting a temperature of a hard disk drive (HDD) during testing. An HDD test program is performed within a pre-determined optimal test temperature range. The HDD is kept within this pre-determined test temperature range by switching HDD operation modes back and forth between a higher heat generating Rapid Seek Mode and a lower heat generating IDLE mode. The HDD is thus kept within the optimal test temperature range without the use of external heating and/or cooling devices.
    Type: Grant
    Filed: September 30, 2003
    Date of Patent: November 14, 2006
    Assignee: Hitachi Global Storage Technologies Netherlands B.V.
    Inventors: Jorge F. Escobar, Andrei Khurshudov