Controlled By Memory Device Patents (Class 360/78.07)
  • Patent number: 11977754
    Abstract: In accordance with one implementation, a method for adaptive in-field recalibration includes detecting a potential environmental disturbance for a first storage node in a mass storage system based on an indicator external to the first storage node, and initiating a recalibration of an operational parameter of the first storage node responsive to the detection.
    Type: Grant
    Filed: August 6, 2021
    Date of Patent: May 7, 2024
    Assignee: SEAGATE TECHNOLOGY LLC
    Inventors: Stephen S. Huh, Christopher R. Fulkerson
  • Patent number: 11908509
    Abstract: Methods, apparatuses, and systems related to operations for managing the quality of an input signal received by a device and for providing feedback in real-time. A controller can provide a reference signal to the device for the input quality check. The memory can implement the input quality check by counting the number of transitions of the reference signal for a set time period and store the resulting count value(s). The memory can use the count value(s) to determine a condition or a quality for the reference signal.
    Type: Grant
    Filed: March 23, 2022
    Date of Patent: February 20, 2024
    Assignee: Micron Technology, Inc.
    Inventors: John E. Riley, Scott E. Smith, Jennifer E. Taylor, Gary L. Howe
  • Patent number: 11862197
    Abstract: According to one embodiment, a magnetic disk device which includes two or more independently drivable actuator blocks and performs seek control with a low jerk in which a jerk that is a derivative of acceleration is limited, wherein in a state where a first actuator block is not accessing a data sector of a disk, a second actuator block that is not the first actuator block accesses the data sector of the disk by seek control with a high Jerk.
    Type: Grant
    Filed: August 10, 2022
    Date of Patent: January 2, 2024
    Assignees: Kabushiki Kaisha Toshiba, Toshiba Electronic Devices & Storage Corporation
    Inventor: Daisuke Sudo
  • Patent number: 11829218
    Abstract: Aspects of a storage device are provided which apply advanced thermal throttling in response to temperature changes based on multiple thermal power states for different types of cells, such as SLCs and MLCs. Initially, a controller determines that a temperature of the memory meets a thermal throttling threshold of a plurality of thermal throttling thresholds. Subsequently, the controller transitions into a thermal power state of a plurality of thermal power states when the temperature meets the thermal throttling threshold. The controller applies a thermal mitigation configuration associated with the thermal power state. The controller then determines that the temperature of the memory has reached a thermal equilibrium in the thermal power state based on the thermal mitigation configuration. Storage device performance is thus improved through advanced thermal throttling without compromising data integrity.
    Type: Grant
    Filed: May 10, 2022
    Date of Patent: November 28, 2023
    Assignee: WESTERN DIGITAL TECHNOLOGIES, INC.
    Inventors: Dmitry Vaysman, Sartaj Ajrawat, Judah Gamliel Hahn, Julian Vlaiko
  • Patent number: 11822401
    Abstract: Aspects of a storage device are provided that apply history-based prediction modeling in advanced thermal throttling. Initially, a controller determines a temperature prediction based one or more thermal mitigation parameters using a history-based prediction model. Subsequently, the controller determines whether the temperature prediction indicates that an actual temperature of the memory is expected to meet a thermal throttling threshold of a plurality of thermal throttling thresholds. The controller then transitions into a thermal power state of a plurality of thermal power states when the temperature prediction indicates that the actual temperature of the memory is expected to meet the thermal throttling threshold. The controller applies a thermal mitigation configuration associated with the thermal power state and determines that the temperature of the memory has reached a thermal equilibrium based on the thermal mitigation configuration.
    Type: Grant
    Filed: May 10, 2022
    Date of Patent: November 21, 2023
    Assignee: WESTERN DIGITAL TECHNOLOGIES, INC.
    Inventors: Dmitry Vaysman, Sartaj Ajrawat, Judah Gamliel Hahn, Julian Vlaiko
  • Patent number: 11615811
    Abstract: A seek operation of a first actuator in a multi-actuator drive is modified, so that one or more disturbance-generating portions of the seek operation do not adversely affect operation of a second actuator in the drive. Radial motion of the aggressor actuator is controlled by limiting a slew rate of the first actuator during one or more portions of the seek operation to be less than or equal to a threshold value. Because slew rate of the first actuator is the rate of change of radial acceleration of the aggressor actuator with respect to time, limiting the slew rate of the first actuator prevents or reduces mechanical disturbances caused by jerk associated with motion of the first actuator.
    Type: Grant
    Filed: August 27, 2021
    Date of Patent: March 28, 2023
    Assignees: Kabushiki Kaisha Toshiba, Toshiba Electronic Devices & Storage Corporation
    Inventors: Siri S. Weerasooriya, Richard M. Ehrlich, Thorsten Schmidt
  • Patent number: 10839839
    Abstract: A data storage device is disclosed comprising a first actuator configured to actuate a first head over a first disk surface, and a second actuator configure to actuate a second head over a second disk surface. A first seek of the first head over the first disk surface is initiated during a first seek time based on a first seek profile. A second seek of the second head over the second disk surface is initiated during a second seek time based on a second seek profile. When the second seek time at least partially overlaps the first seek time and at least the second seek profile is a de-rated seek profile, the second seek profile is adjusted to avoid an overcurrent condition.
    Type: Grant
    Filed: February 4, 2020
    Date of Patent: November 17, 2020
    Assignee: Western Digital Technologies, Inc.
    Inventors: Hiroshi Uchida, Hidehiko Numasato, KeXiu Liu, Shrey Khanna
  • Patent number: 10802731
    Abstract: Described is storage system and method for reducing power consumption. The storage system has first and second physical disks configured to provide mirroring. The first physical disk is placed into a power-saving mode of operation, while the second physical disk is in an active mode of operation responding to read and write requests. The first physical disk transitions from the power-saving mode of operation to an active mode of operation for destaging writes pending from cache to the first physical disk, while the second physical disk responds to read and write requests. The second physical disk transitions from the active mode of operation to the power-saving mode of operation, while the first physical disk responds to read and write requests.
    Type: Grant
    Filed: January 28, 2019
    Date of Patent: October 13, 2020
    Assignee: EMC IP HOLDING COMPANY LLC
    Inventors: Adnan Sahin, Sachin More, Preston Crow, Ron Arnan
  • Patent number: 9500838
    Abstract: A lens driving apparatus for a lens includes a voice coil motor. A coil position of a coil is detected. A table memory stores a correction factor for each one of plural values of the coil position according to flux density distribution. The correction factor is read from the table memory according to the detected coil position. A coil current is corrected by use of the correction factor for each coil position. The corrected coil current is caused to flow through the coil, with which the lens is moved together along an optical axis. Consequently, changes in a moving speed of the lens can be prevented.
    Type: Grant
    Filed: March 27, 2015
    Date of Patent: November 22, 2016
    Assignee: FUJIFILM Corporation
    Inventor: Shinichi Shimotsu
  • Patent number: 9165583
    Abstract: A data storage device is disclosed comprising a head actuated over a disk comprising a plurality of tracks, and a load/unload ramp. When seeking the head a seek length from a starting track to an ending track, control circuit is configured to adjust a seek profile when the seek length is greater than a first threshold and the ending track is within a second threshold of the load/unload ramp.
    Type: Grant
    Filed: October 29, 2014
    Date of Patent: October 20, 2015
    Assignee: Western Digital Technologies, Inc.
    Inventor: Orhan Beker
  • Patent number: 8442684
    Abstract: A control system for achieving high-speed torque for a joint of a robot includes a printed circuit board assembly (PCBA) having a collocated joint processor and high-speed communication bus. The PCBA may also include a power inverter module (PIM) and local sensor conditioning electronics (SCE) for processing sensor data from one or more motor position sensors. Torque control of a motor of the joint is provided via the PCBA as a high-speed torque loop. Each joint processor may be embedded within or collocated with the robotic joint being controlled. Collocation of the joint processor, PIM, and high-speed bus may increase noise immunity of the control system, and the localized processing of sensor data from the joint motor at the joint level may minimize bus cabling to and from each control node. The joint processor may include a field programmable gate array (FPGA).
    Type: Grant
    Filed: September 22, 2009
    Date of Patent: May 14, 2013
    Assignees: GM Global Technology Operations LLC, The United States of America as represented by the Administrator of the National Aeronautics and Space Administration, Oceaneeering Space Systems
    Inventors: Donald R. Davis, Nicolaus A. Radford, Frank Noble Permenter, Michael C. Valvo, R. Scott Askew
  • Patent number: 8311654
    Abstract: A content reproducing apparatus is disclosed which includes: a sensor; a discrimination circuit configured to discriminate whether a movement of a user is a first movement or a second movement based on a detection output from the sensor; a storage configured to store contents; a reproduction circuit configured to reproduce the contents; and a control circuit configured to supply the reproduction circuit with contents retrieved from the storage in accordance with a discrimination output from the discrimination circuit.
    Type: Grant
    Filed: February 5, 2007
    Date of Patent: November 13, 2012
    Assignee: Sony Corporation
    Inventors: Yoichiro Sako, Kenichi Makino, Akane Sano, Katsuya Shirai, Motoyuki Takai, Makoto Inoue
  • Patent number: 8090242
    Abstract: A method and apparatus for reproducing titles are discussed. According to an embodiment, the method includes determining if at least one title satisfies a criterion, using an average length information of a plurality of titles recorded on a recording medium; and reproducing the at least one title if the determining step determines that the at least one title satisfies the criterion.
    Type: Grant
    Filed: July 10, 2006
    Date of Patent: January 3, 2012
    Assignee: LG Electronics Inc.
    Inventor: Han Seop Ryu
  • Publication number: 20110205664
    Abstract: An information storing device and an information processing device having a memory for registering a plurality of working modes at recording/reproduction and a switching circuit for selecting one of the plurality of working modes, which select the optimum working mode automatically or by an instruction of an operator according to power supply capacity of a device of higher rank to effect recording/reproduction.
    Type: Application
    Filed: October 20, 2010
    Publication date: August 25, 2011
    Applicant: HITACHI GLOBAL STORAGE TECHNOLOGIES JAPAN, LTD.
    Inventors: Yuichi KOIZUMI, Hideaki AMANO, Katsuhiro TSUNETA, Koji KODAMA
  • Patent number: 7957090
    Abstract: There is provided a method for generating acceleration data used in feed-forward control of head seeking, wherein, a seek distance and one of a seek period and the count of samples are received; a weighting factor for the change rate of acceleration between adjacent sample times is determined respectively; and an optimum acceleration at each sample time is obtained by performing an optimization calculation that minimizes an objective function under a constraint condition based on variables representing accelerations at each sample time, either the seek period or the count of samples, and the seek distance.
    Type: Grant
    Filed: October 23, 2008
    Date of Patent: June 7, 2011
    Assignee: Kabushiki Kaisha Toshiba
    Inventors: Yoshiyuki Ishihara, Shinji Takakura
  • Patent number: 7826168
    Abstract: A head position control method controls the position of a head by correcting components synchronizing rotation of a disk based on the head control amount. A correction signal for components synchronizing rotation is generated by using a filter function. The filter function that integrates the sine and cosine terms of DFT and inverse DFT and forms multiply of the complex values a(m) and b(m) and sine and cosine for frequency conversion, is measured in advance. The complex values are the m degree of RRO frequencies having frequency characteristics to be multiplied (1+C(z)P(z)) or ?(1+C(z)P(z)/P(z)).
    Type: Grant
    Filed: March 22, 2005
    Date of Patent: November 2, 2010
    Assignee: Toshiba Storage Device Corporation
    Inventor: Kazuhiko Takaishi
  • Patent number: 7800855
    Abstract: Embodiments of the present invention help to prevent destabilization in voice coil motor (VCM) velocity control. According to one embodiment, a hard disk controller/multiprocessing unit (HDC/MPU) calibrates a correction operational coefficient of a detected back electromotive force (EMF) voltage before unloading. The calibration is carried out in a state that an actuator is pivoting. The HDC/MPU calibrates the correction coefficient according to a motion equation of the actuator using VCM current applied to a VCM and a detected value of a back EMF voltage detection circuit.
    Type: Grant
    Filed: November 14, 2007
    Date of Patent: September 21, 2010
    Assignee: Hitachi Global Storage Technologies Netherlands B.V.
    Inventors: Kenichi Kuramoto, Shinya Sakamoto, Nobuhiko Wasa, Sayaka Nojiri, Hidefumi Tominaga
  • Patent number: 7660070
    Abstract: a seek procedure for a hard disk drive which provides a significant reduction in acoustic noise as well as high performance fast seek times is described. The seek procedure lowers the peak acceleration for short seeks and imparts a smooth transition from a sine seek to an exponential arrival at the target track. The seek procedure provides an error free feedforward signal derived from a single sine table. The procedure which contains a time domain sinusoid acceleration feedforward combined with a phase-plane trajectory controlled velocity which, near seek completion. The procedure is constructed so that the acceleration begins at zero and, in the fashion of a sine, increases to a maximum, decreases to a minimum and then increases again until a computed switchpoint is reached. The switchpoint is determined in-situ, to provide a smooth and continuous velocity transition from sinusoid to exponential. The velocity trajectory is computed from a look-up table.
    Type: Grant
    Filed: March 8, 2007
    Date of Patent: February 9, 2010
    Assignee: ESGW Holdings Limited
    Inventors: Doug Frisby, Jim Hargarten
  • Patent number: 7636605
    Abstract: A feedback controller performs a feedback control based on an error between a target position and an actual position of a head. A model controller obtains a control command, a model position to be output as a command for the target position to the feedback controller, and a model velocity for the head to follow a target velocity, by using a preset control equation model, and obtains the control command and the model position with the target position as an input, based on a differential value of the target velocity corresponding to a remaining distance from the model position to the target position.
    Type: Grant
    Filed: March 19, 2007
    Date of Patent: December 22, 2009
    Assignee: Kabushiki Kaisha Toshiba
    Inventor: Shinji Takakura
  • Patent number: 7619849
    Abstract: Embodiments in accordance with the present invention provide a magnetic disk drive with reduced noise during seek operation without causing any delay in control response. According to one embodiment of the present invention, a control circuit of a magnetic disk drive controls the drive power supplied to a voice coil motor during a seek operation adapted to move a magnetic head over a target track formed on a magnetic disk so as to bring the travel speed of the magnetic head close to a predetermined target speed. The control circuit determines a provisional current according to the difference between the predetermined target speed and an actual travel speed in an acceleration zone adapted to accelerate the magnetic head to the predetermined target speed. If the provisional current exceeds a limit specified in relation to an elapsed time from the start of acceleration, the control circuit sets the limit as the current of the drive power supplied to the voice coil motor to control the motor.
    Type: Grant
    Filed: April 26, 2007
    Date of Patent: November 17, 2009
    Assignee: Hitachi Global Storage Technologies Netherlands B.V.
    Inventors: Hiroshi Uchida, Isao Yoneda, Hideki Ohzeki
  • Patent number: 7613525
    Abstract: Embodiments of the invention provide a disk device and a method of controlling the device which is capable of suppressing peak current, even for serial communication, that is required when initiating rotation of a spindle motor down to a level equivalent to that of parallel communication, without prolonging elapsed time before reaching the steady rotation speed. In one embodiment, an HDD includes a serial communication circuit which executes serial communication with a host, an SPM which rotates a disk, an HDC/MPU which controls the SPM and the serial communication circuit. The HDC/MPU, after shutting down the serial communication circuit once, starts up the serial communication circuit again when rotation speed of the SPM reached the specified standard value, and establishes serial communication with the host by means of the serial communication circuit.
    Type: Grant
    Filed: September 19, 2005
    Date of Patent: November 3, 2009
    Assignee: Hitachi Global Storage Technologies Netherlands B.V.
    Inventors: Kenji Ogasawara, Hirofumi Saitoh
  • Patent number: 7602581
    Abstract: Methods and apparatus of the present invention allow for interpolated Just in Time (iJIT) seek command control of hard drive actuators.
    Type: Grant
    Filed: October 10, 2007
    Date of Patent: October 13, 2009
    Assignee: Hitachi Global Storage Technologies Netherlands B.V.
    Inventors: Nyles Heise, Hung M. Vu
  • Patent number: 7595957
    Abstract: Apparatus and related methods are described for adjusting servo gain. In an exemplary apparatus, a circuit determines a bias force error that occurs between an estimated bias force and an actual bias force on an actuator during movement by a servo motor. The circuit adjusts a servo gain in response to the bias force error, and regulates movement of the actuator by the servo motor in response to the servo gain.
    Type: Grant
    Filed: June 29, 2007
    Date of Patent: September 29, 2009
    Assignee: Seagate Technology LLC
    Inventors: KeXiu Liu, JianGuo Zhou, MingZhong Ding, KianKeong Ooi, WenJun Cao
  • Patent number: 7580219
    Abstract: Controlling seeking of a transducer includes accelerating the transducer to a seek velocity, generating a linearized switching curve defining a position and velocity of the transducer at which deceleration should begin, and controlling the velocity of the transducer in response to the current position and seek velocity of the transducer relative to the linearized switching curve. The linearized switching curve has a slope and an offset that are determined in response to the seek velocity and a current position of the transducer relative to a nonlinear switching curve.
    Type: Grant
    Filed: February 21, 2007
    Date of Patent: August 25, 2009
    Assignee: Seagate Technology LLC
    Inventors: Jeffrey V. Derosa, Orhan Beker
  • Patent number: 7538971
    Abstract: Embodiments of the present invention allow for controlling a microactuator based at least in part on an output of a temperature sensor. Also, embodiments of the present invention allow for adjusting a control of a microactuator so as to compensate for changes in a gain of the microactuator due to changes in temperature.
    Type: Grant
    Filed: April 25, 2007
    Date of Patent: May 26, 2009
    Assignee: Maxtor Corporation
    Inventors: Yu Sun, Xiaoping Hu
  • Patent number: 7515375
    Abstract: The present invention provides a positioning control device and a disk device for shortening a calculation delay time. Upon detection of a position signal from a demodulation circuit, an MCU of the disk device calculates a position error, and following calculation of a control amount, executes determination and correction processing. A variable value prior to the start of calculation is stored in a save area of a memory (or a save memory) such that when the variable value is to be reset as a result of the determination and correction processing, the variable value is read from the save area, the reset variable value is stored in an overwrite area of the memory (or an overwrite memory), and calculation of the control amount is re-executed.
    Type: Grant
    Filed: June 27, 2006
    Date of Patent: April 7, 2009
    Assignee: Fujitsu Limited
    Inventor: Kazuhiko Takaishi
  • Patent number: 7515376
    Abstract: A method of manufacturing a disk drive is disclosed in which servo information is written in tracks on a disk surface, the track width performance of the associated read/write transducer is measured, the track width performance is analyzed and a data track pitch is established. Based on the data track pitch established, a track location formula for data tracks on the surface is defined. For a disk drive with a plurality of read/write transducer-media surface combinations, a track location formula for data tracks is established for each combination.
    Type: Grant
    Filed: March 7, 2008
    Date of Patent: April 7, 2009
    Assignee: Mobile Storage Technology, Inc.
    Inventors: Bruce D. Emo, Brian D. Wilson
  • Patent number: 7463439
    Abstract: A magnetic disk device includes a position and velocity demodulating circuit. In the position and velocity demodulating circuit, a difference calculating unit demodulates a moving velocity of a magnetic head based on a phase difference in servo signals as servo data in the same sector. An overflow detecting unit detects an overflow of the demodulated moving velocity and calculates a correction value for the overflow. The overflow is corrected based on the correction value. The corrected overflow is further corrected by a correction value of a repeatable velocity error for the demodulated velocity to output an accurate demodulated velocity.
    Type: Grant
    Filed: February 1, 2007
    Date of Patent: December 9, 2008
    Assignee: Fujitsu Limited
    Inventor: Kazuhiko Takaishi
  • Patent number: 7420764
    Abstract: The invention applies to servo controllers for at least the voice coil motor of a hard disk drive. Today, many control algorithms require 80 to 90 percent of the sampling period to complete their calculation of the next control, making computation time delay no longer negligible. The invention accommodates the transport delay, such as computation time delay, into the state estimator and into the whole control system. Experimental results using a commercial hard drive, as well as simulation results, show that the invention's method effectively improves the hard disk drive control system stability by increasing the phase margin and gain margin. The invention includes the method of operating the servo-controller, as well as the apparatus implementing that method. The invention also includes hard disk drives containing servo-controllers implementing the method, and program systems residing in accessibly coupled memory to a computer within the servo controller implementing the method.
    Type: Grant
    Filed: April 3, 2006
    Date of Patent: September 2, 2008
    Assignee: Samsung Eletronics Co., Ltd.
    Inventors: Young-Hoon Kim, Sang Hoon Chu, Seong-Woo Kang, Dong-Ho Oh, Yun-Sik Han, Tae Yeon Hwang
  • Publication number: 20080151417
    Abstract: A method of manufacturing a disk drive is disclosed in which servo information is written in tracks on a disk surface, the track width performance of the associated read/write transducer is measured, the track width performance is analyzed and a data track pitch is established. Based on the data track pitch established, a track location formula for data tracks on the surface is defined. For a disk drive with a plurality of read/write transducer-media surface combinations, a track location formula for data tracks is established for each combination.
    Type: Application
    Filed: March 7, 2008
    Publication date: June 26, 2008
    Inventors: Bruce D. Emo, Brian D. Wilson
  • Patent number: 7388726
    Abstract: A disk drive includes a slider assembly and a controller that directs current to the slider assembly to dynamically adjust the head-to-disk spacing. In one embodiment, the slider assembly includes a write element having a first end, a second end and an intermediate section, a conductor that is connected to the intermediate section. In this embodiment, the controller directs electrical current through the conductor to heat the write element without writing data to a storage disk. The electrical current can be directed through the conductor at any time prior to data transfer or during data transfer. Heating the write element causes a deformation of the slider assembly to decrease the head-to-disk spacing. In another embodiment, the slider assembly includes a separate slider deformer. Electrical current is selectively directed to the slider deformer to cause a deformation of the slider assembly to obtain a desired head-to-disk spacing.
    Type: Grant
    Filed: August 10, 2006
    Date of Patent: June 17, 2008
    Assignee: Seagate Technology LLC
    Inventors: Robert McKenzie, Thao Nguyen, Xiaokun Chew, Gang Herbert Lin, Jack Tsai, Bruce Schardt, Steven Marshall
  • Publication number: 20080106817
    Abstract: A hard disk drive that includes a voice coil motor controlled by a servo. The servo provides a driving signal that has multiple sinusoidal waveforms. The multi-sinusoidal waveforms minimize seek time and vibrations in the drive.
    Type: Application
    Filed: September 27, 2006
    Publication date: May 8, 2008
    Applicant: Samsung Electronics Co., Ltd.
    Inventors: Chang-Ik Kang, Young-Hoon Kim, Sang-Hoon Chu
  • Publication number: 20080100956
    Abstract: A hard disk drive with a voice coil motor circuit that provides a current to a voice coil motor to perform a seek routine in a seek time. The disk drive includes a temperature sensor to sense a temperature of the disk drive and a voltage sensor to sense the voltage of the voice coil motor. The circuit adjust the seek time dependent upon the sensed temperature and voltage. By way of example, the circuit will increase the seek time if there is an increase in temperature and/or a decrease in voltage.
    Type: Application
    Filed: October 25, 2006
    Publication date: May 1, 2008
    Applicant: Samsung Electronics Co., Ltd.
    Inventor: Chang-Ik Kang
  • Patent number: 7342741
    Abstract: A method of manufacturing a disk drive is disclosed in which servo information is written in tracks on a disk surface, the track width performance of the associated read/write transducer is measured, the track width performance is analyzed and a data track pitch is established. Based on the established track pitch, a track location formula for data tracks on the disk surface is defined. For a disk drive having a plurality of read/write transducers, a track location formula is established for each transducer. A method for measuring track width performance of a read/write head is also disclosed.
    Type: Grant
    Filed: February 10, 2000
    Date of Patent: March 11, 2008
    Assignee: ESGW Holdings Limited
    Inventors: Bruce D. Emo, Brian D. Wilson
  • Publication number: 20070253100
    Abstract: Embodiments in accordance with the present invention provide a magnetic disk drive with reduced noise during seek operation without causing any delay in control response. According to one embodiment of the present invention, a control circuit of a magnetic disk drive controls the drive power supplied to a voice coil motor during a seek operation adapted to move a magnetic head over a target track formed on a magnetic disk so as to bring the travel speed of the magnetic head close to a predetermined target speed. The control circuit determines a provisional current according to the difference between the predetermined target speed and an actual travel speed in an acceleration zone adapted to accelerate the magnetic head to the predetermined target speed. If the provisional current exceeds a limit specified in relation to an elapsed time from the start of acceleration, the control circuit sets the limit as the current of the drive power supplied to the voice coil motor to control the motor.
    Type: Application
    Filed: April 26, 2007
    Publication date: November 1, 2007
    Applicant: Hitachi Global Storage Technologies Inc.
    Inventors: Hiroshi Uchida, Isao Yoneda, Hideki Ohzeki
  • Publication number: 20070253096
    Abstract: A rate of occurrence of off-track write events is determined. A seek function control parameter for a head is adaptively adjusted based on the determined rate of occurrence of the off-track write events. Related circuits and devices are also discussed.
    Type: Application
    Filed: April 26, 2007
    Publication date: November 1, 2007
    Inventors: Steven J. Alfred, Charles R. Watt
  • Patent number: 7289290
    Abstract: A method of controlling a track seek servo in a hard disk drive and an apparatus therefor. A method of controlling a track seek servo includes moving a transducer to a track with an acceleration trajectory generated by a convolution operation, a rate of change of acceleration of the transducer being zero at a beginning and an end of a track seek operation in a track seek mode.
    Type: Grant
    Filed: October 20, 2004
    Date of Patent: October 30, 2007
    Assignee: Samsung Electronics Co., Ltd.
    Inventor: Sang-cheol Lee
  • Patent number: 7259933
    Abstract: A method for generating a velocity command for an actuator assembly is provided. The actuator assembly includes an actuator arm, which is to move over a plurality of surfaces. The method begins by providing a compensation torque for each of the plurality of surfaces. A position of the actuator arm is determined so that it may be mapped to one of the plurality of surfaces, which is the present surface over which the actuator arm is moving. A target velocity is then provided for the actuator arm and input to a controller, which generates a velocity command from the target velocity and a selected compensation torque, which is the compensation torque of the present surface.
    Type: Grant
    Filed: May 27, 2005
    Date of Patent: August 21, 2007
    Assignee: Seagate Technology LLC
    Inventors: Lee Ling Tan, Xiong Liu, Choon Kiat Lim
  • Patent number: 7215503
    Abstract: A method, computer program product, and apparatus for controlling the arrival of a disc drive actuator arm assembly using a time-linear arrival profile are disclosed. A reference velocity is calculated as a function of the current position of the arm assembly and the amount of time left to complete the seek operation, where the first derivative of the reference velocity function with respect to time varies linearly with respect to time. This reference velocity is used to control the actual velocity of an arm assembly. In a preferred embodiment, this time-linear arrival is utilized in the second stage of a two-stage arrival sequence, in which the arm assembly follows a constant-acceleration profile during the first stage.
    Type: Grant
    Filed: June 20, 2003
    Date of Patent: May 8, 2007
    Assignee: Seagate Technology LLC
    Inventor: Apurva Dolatrai Naik
  • Patent number: 7158334
    Abstract: A head positioning control system which is applied to a disk drive is disclosed. The system includes a feedback control system which performs head positioning control of a head and a feedforward control system. The feedforward control system detects the amplitude and phase of a disturbance based on the position error between the position of the head and a target position. The feedforward control system computes a disturbance compensation value for eliminating the disturbance to output the disturbance compensation value to the feedback control system based on each detection result of the amplitude and the phase.
    Type: Grant
    Filed: March 25, 2005
    Date of Patent: January 2, 2007
    Assignee: Kabushiki Kaisha Toshiba
    Inventor: Masafumi Iwashiro
  • Patent number: 7136258
    Abstract: A technique for adaptively and stably updating the feed forward value required to drive the head of a rotational recording apparatus. A trajectory of a target position is generated for each seek command by using a compound function comprising a ramp function and a sine-wave function. The sine-wave element of the target position is transmitted to an adaptive filter for updating coefficients of the compound formula. All elements other than the sine-wave element are removed to provide a smooth update of the compound function's coefficients.
    Type: Grant
    Filed: September 12, 2002
    Date of Patent: November 14, 2006
    Assignee: Hitachi Global Storage Technologies Netherlands B.V.
    Inventor: Masashi Kisaka
  • Patent number: 7136256
    Abstract: A head positioning method and device positions a head which reads a disk-type storage medium at a specified location, and accurately estimates a bias value during settling control. A disk device includes a disk medium, a head, an actuator, and a control circuit, and settling control is performed based on a detected position after coarse control without integral compensation or bias compensation having been performed. The position of the head for a next sample is estimated, and an initial bias value is estimated from the difference between the detected position and the estimated position. This initial bias value is then used to perform settling control together with integral compensation of bias compensation. Since the accurate initial bias value at the start of settling is estimated, it is possible to reduce the time for correcting the shift in the bias during settling control, and greatly reduce the time required for settling control.
    Type: Grant
    Filed: June 28, 2005
    Date of Patent: November 14, 2006
    Assignee: Fujitsu Limited
    Inventors: Kazuhiko Takaishi, Shunji Saito
  • Patent number: 7116515
    Abstract: A method and apparatus to compensate for a difference between an actual torque constant and a modeling torque constant used for servo design in a disc drive. The method has operations of: performing predetermined test seeks with respect to test seek positions into which a disc is divided; obtaining torque compensation constants from the test seeks; storing the torque compensation constants in a torque compensation constant table; and compensating for a gain of a seek control loop at a position where a seek is performed in a seek mode, using the torque compensation constants stored in the torque compensation constant table.
    Type: Grant
    Filed: December 3, 2004
    Date of Patent: October 3, 2006
    Assignee: Samsung Electronics Co., Ltd.
    Inventors: Sang-hoon Chu, Yong-gwon Lee, Cheol-hoon Park
  • Patent number: 7082010
    Abstract: A method and apparatus for reducing seek acoustics in a disk drive using feedback during large current transitions is provided. A desired transition profile, which uses feedback, is followed in order to smoothen transitions of a commanded current profile that is supplied to a VCM for moving a head relative to a disk surface during a seek operation. Linear interpolation is used to provide feedback for following the desired transition profile.
    Type: Grant
    Filed: November 12, 2002
    Date of Patent: July 25, 2006
    Assignee: Maxtor Corporation
    Inventors: Fred Hansen, Unkyong Hand, Fernando Zayas
  • Patent number: 7061714
    Abstract: A disk drive is disclosed comprising a disk, a head, and a voice coil motor (VCM) for actuating the head over the disk. The disk drive executes a rotational position optimization (RPO) algorithm to select a next command to execute relative to an estimated seek time computed for each command in a command queue. A seek time parameter is estimated and a seek time delta computed in response to the estimated seek time parameter. The seek time delta is added to a nominal estimated seek time to generate a modified estimated seek time for each command in the command queue, thereby optimizing the RPO algorithm.
    Type: Grant
    Filed: December 19, 2003
    Date of Patent: June 13, 2006
    Assignee: Western Digital Technologies, Inc.
    Inventor: Jie Yu
  • Patent number: 7031095
    Abstract: The invention applies to servo controllers for at least the voice coil motor of a hard disk drive. Today, many control algorithms require 80 to 90 percent of the sampling period to complete their calculation of the next control, making computation time delay no longer negligible. The invention accommodates the transport delay, such as computation time delay, into the state estimator and into the whole control system. Experimental results using a commercial hard drive, as well as simulation results, show that the invention's method effectively improves the hard disk drive control system stability by increasing the phase margin and gain margin. The invention includes the method of operating the servo-controller, as well as the apparatus implementing that method. The invention also includes hard disk drives containing servo-controllers implementing the method, and program systems residing in accessibly coupled memory to a computer within the servo controller implementing the method.
    Type: Grant
    Filed: July 29, 2004
    Date of Patent: April 18, 2006
    Assignee: Samsung Electronics Co., Ltd.
    Inventors: Young-Hoon Kim, Sang Hoon Chu, Seong-Woo Kang, Dong-Ho Oh, Yun-Sik Han, Tae Yeon Hwang
  • Patent number: 6995946
    Abstract: Methods relating to compensating a pre-defined seek profile for use in a data storage device, such as a disc drive, to manage the internal temperature of the device are disclosed. One embodiment disclosed is related to determining a seek profile compensation value that can be used to compensate the pre-defined seek profile for temperature. Another embodiment is a method of using a seek profile compensation value during device operation to maintain the data storage device operating temperature below an operating temperature threshold. Yet another embodiment of the present invention may be thought of as a controller for a data storage device. The controller comprises a microprocessor having a pre-determined seek profile and a means for compensating the pre-determined seek profile based on a current operating temperature.
    Type: Grant
    Filed: June 27, 2003
    Date of Patent: February 7, 2006
    Assignee: Seagate Technology LLC
    Inventors: Mingzhong Ding, KianSoon Yeo, JianYi Wang, KianKeong Ooi, BengWee Quak
  • Patent number: 6940684
    Abstract: When a head passes over a track with a projected item in a seek operation, the CPU delays a seek start time to conduct the seek by changing a period of time from a seek start position to a position of the track with a projected item. Or, the CPU conducts seek control by changing a speed table. Or, the CPU changes a sequence of items of a tag queue to obtain a seek locus not passing the projected item. By the control operation, a seek error due to thermal asperity is prevented and the head is not damaged. This also prevents appearance of a new projected item produced by contact between the magneto-resistive head and the projected item on the recording medium.
    Type: Grant
    Filed: February 24, 2003
    Date of Patent: September 6, 2005
    Assignee: Hitachi Global Storage Technologies Japan, Ltd.
    Inventors: Masaki Yoshioka, Kenichi Masuda, Yuji Hata, Takeshi Nakazawa, Takayuki Umemoto
  • Patent number: 6927935
    Abstract: There is disclosed a disk drive using a disk medium in which a non-servo range exists. In order to position a head at a target track, a CPU executes a seek operation by normal velocity control using servo data. At this positioning, when the head passes the non-servo range from which no servo data can be obtained, the CPU executes a seek operation by special velocity control to move the head at a velocity calculated based on a moving distance of the non-servo range.
    Type: Grant
    Filed: March 19, 2004
    Date of Patent: August 9, 2005
    Assignee: Kabushiki Kaisha Toshiba
    Inventor: Koji Yano
  • Patent number: 6909576
    Abstract: Provided are a method, system, and program for initializing a storage device. A pulse response profile is determined for a storage system in response to a series of signals generated to seek to a location in the storage system. A determination is made of a desired response trajectory for the storage system that optimizes seek performance. An adjustment vector is calculated based on the pulse and step response profiles and the desired response trajectory to optimize the pulse response profile. The adjustment vector is stored in the storage device for use during storage device operations to apply to control signals generated to perform one seek operation.
    Type: Grant
    Filed: August 22, 2002
    Date of Patent: June 21, 2005
    Assignee: Hitachi Global Storage Technologies Netherlands B.V.
    Inventor: Mantle Man-Hon Yu