Patents by Inventor Nhan X. Bui

Nhan X. Bui has filed for patents to protect the following inventions. This listing includes patent applications that are pending as well as patents that have already been granted by the United States Patent and Trademark Office (USPTO).

  • Patent number: 9087539
    Abstract: Controlling the position of a head within a tape transport system. A track-follow control system (TFCS) includes a controller device for generating a control signal as a function of a position error signal (PES), wherein the PES indicates a difference between the actual and target positions of the head relative to the tape, and an actuator for changing the actual position. The TFCS is adapted to select a controller device configuration from a plurality of configurations dependent on an operating tape speed. The configurations are predetermined depending on a vibration frequency domain profile indicative of environmental vibrations induced to the head and tape to determine the control signal for adjusting an actuator output signal relative to a lateral tape motion signal. The TFCS is also adapted to feed-back a signal depending on a difference of the actuator output signal and the lateral tape motion signal to generate the PES.
    Type: Grant
    Filed: June 26, 2014
    Date of Patent: July 21, 2015
    Assignee: INTERNATIONAL BUSINESS MACHINES CORPORATION
    Inventors: Armando J Argumedo, Nhan X Bui, David H Harper, Randy C Inch, Kevin B Judd, Mark A Lantz, Angeliki Pantazi, Tomoko Taketomi
  • Publication number: 20150199986
    Abstract: A method according to one embodiment includes generating or receiving a value representative of a lateral position of a tape. The value is used to adjust a position of a coarse actuator in response to determining that the value is in a first range relative to a first threshold. An integrator center value is used to adjust the position of the coarse actuator in response to determining that the value is in a second range relative to the first threshold.
    Type: Application
    Filed: March 3, 2015
    Publication date: July 16, 2015
    Inventors: Nhan X. Bui, Angeliki Pantazi, Tomoko Taketomi
  • Publication number: 20150193173
    Abstract: In one embodiment, a system includes a storage cloud comprising storage media, a cartridge memory (CM) database stored to the storage media, and a storage controller, wherein the storage controller is configured to communicate with one or more data storage drives located in one or more data storage libraries, each data storage drive being configured to write and/or read data to/from a plurality of data storage cartridges therein, and control the one or more data storage libraries as a single logical library, wherein the CM database includes a plurality of entries, each entry corresponding to a data storage cartridge. In another embodiment, the data storage cartridge includes a data storage medium configured to store more than about 100 MB of data, a physical CM configured to store less than about 100 KB of data, and a visible indicator displayed on an exterior of the housing.
    Type: Application
    Filed: January 7, 2014
    Publication date: July 9, 2015
    Applicant: INTERNATIONAL BUSINESS MACHINES CORPORATION
    Inventors: Allen K. Bates, Nhan X. Bui, Octaviano G. Gomez, Marie L. E. Romero, Stephen L. Schwartz, Daniel J. Winarski
  • Patent number: 9070401
    Abstract: Dynamic reconfiguration-switching of motor windings in a disk drive is optimized between winding-configurations by selectively lowering resistance of a constantly used portion of one of the motor windings. Acceleration is traded off in favor of higher velocity upon detecting the electric motor in the electric vehicle is at an optimal angular-velocity for switching to an optimal lower torque constant and voltage constant. The total back electromotive force (BEMF) is prohibited from inhibiting further acceleration to a higher angular-velocity.
    Type: Grant
    Filed: March 1, 2013
    Date of Patent: June 30, 2015
    Assignee: INTERNATIONAL BUSINESS MACHINES CORPORATION
    Inventors: Allen K. Bates, Nhan X. Bui, Reed A. Hancock, Daniel J. Winarski
  • Patent number: 9047897
    Abstract: Various embodiments described herein include processing of a lateral tape motion signal, caused primarily by a tape supply reel (e.g., depending on direction of tape movement). The resulting data may be used, at least in part, to determine placement of a coarse actuator. In one general embodiment, a method includes receiving a signal representative of a lateral position of a magnetic head, and integrating portions of the signal representative of a lateral position of a magnetic head, the portions corresponding to fractions of one or more revolutions of a supply reel for generating first data. The first data is averaged over a value or values corresponding to one or more revolutions of the supply reel for generating second data.
    Type: Grant
    Filed: January 16, 2014
    Date of Patent: June 2, 2015
    Assignee: International Business Machines Corporation
    Inventors: Nhan X. Bui, Randy C. Inch, Tomoko Taketomi
  • Publication number: 20150124348
    Abstract: Provided are a method, system, and program for adjusting tension in a tape media to counter tape dimensional stability (TDS) errors in a tape media. A determination is made of whether to adjust tension of the tape media based on a detected error rate of reading at least one of the tracks. The tension of the tape media is adjusted in response to determining to adjust the tension.
    Type: Application
    Filed: January 15, 2015
    Publication date: May 7, 2015
    Inventors: Nhan X. Bui, Reed A. Hancock, Kevin B. Judd
  • Patent number: 9024550
    Abstract: For an electric motor used as a generator in an electric vehicle for dynamic braking, employing a dynamic reconfiguration-switching of motor windings upon the generator exceeding one of a maximum usable constraint of a first rechargeable battery in order to reduce a voltage constant of the electric motor thereby limiting one of a produced voltage and a produced power.
    Type: Grant
    Filed: March 1, 2013
    Date of Patent: May 5, 2015
    Assignee: International Business Machines Corporation
    Inventors: Tara Astigarraga, Allen K. Bates, Nhan X. Bui, Louie A. Dickens, Reed A. Hancock, Stephen L. Schwartz, Michael E. Starling, Daniel J. Winarski
  • Patent number: 9019651
    Abstract: Provided are a computer program product, system, and method for determining a skew error signal (SES) offset used to determine an SES to adjust heads in a drive unit. A determination is made of a first difference in a first orientation with respect to a direction of movement of the recordable storage media based on first and second position information read by first and second servo read elements on a first head. A determination is made of a second difference in a second orientation with respect to the direction of movement of the recordable storage media based on third and fourth position information read by the first servo read element and a third servo read element on a second head. An offset, calculated based on the determined first and second difference, is used to generate an error signal to adjust the first and second heads.
    Type: Grant
    Filed: May 28, 2014
    Date of Patent: April 28, 2015
    Assignee: International Business Machines Corporation
    Inventors: Nhan X. Bui, Angeliki Pantazi, Tomoko Taketomi, Kazuhiro Tsuruta
  • Patent number: 9013827
    Abstract: Various embodiments include positioning a coarse actuator based, at least in part on lateral motion of a magnetic tape. In one general embodiment, a method includes receiving a value (IntegRevAve) representative of a lateral position of a tape, comparing the value to a first threshold, using the value to adjust a position of a coarse actuator when the value is in a first range relative to the first threshold, and selectively using an integrator center value (IntegCtr) to adjust the position of the coarse actuator when the value is in a second range relative to the first threshold.
    Type: Grant
    Filed: January 16, 2014
    Date of Patent: April 21, 2015
    Assignee: International Business Machines Corporation
    Inventors: Nhan X. Bui, Angeliki Pantazi, Tomoko Taketomi
  • Publication number: 20150098149
    Abstract: A set of lateral positions, of the magnetic medium with respect to the tape reel and a set of longitudinal positions of the magnetic medium with respect to the beginning of the magnetic medium as the magnetic medium comes off the first tape reel, are identified. A record is stored, on a non-volatile storage medium, of the set of lateral positions of the magnetic medium and the set of longitudinal positions of the magnetic medium. The record, of the set of lateral positions of the magnetic medium and the set of longitudinal positions of the magnetic medium as the magnetic medium comes off a second tape reel, is read. A tape head is moved laterally, to the lateral positions in response to the reading of the record of the set of lateral positions of the magnetic medium and the set of longitudinal positions of the magnetic medium.
    Type: Application
    Filed: October 9, 2013
    Publication date: April 9, 2015
    Applicant: International Business Machines Corporation
    Inventors: Allen K. Bates, Nhan X. Bui, Daniel J. Winarski
  • Publication number: 20150092293
    Abstract: In one embodiment, a method includes determining a stopwrite threshold based on a standard deviation or a variance at a current position error signal sample, and determining whether the current position error signal sample exceeds the stopwrite threshold. Writing is disabled in response to determining that the current position error signal sample exceeds the stopwrite threshold. Writing is enabled in response to determining that the current position error signal sample does not exceed the stopwrite threshold.
    Type: Application
    Filed: December 8, 2014
    Publication date: April 2, 2015
    Inventors: Nhan X. Bui, Kevin B. Judd, Tomoko Taketomi
  • Patent number: 8994307
    Abstract: Dynamic reconfiguration-switching of motor windings in a motor is optimized between winding-configurations by selectively lowering resistance of a constantly used portion of one of the motor windings. Acceleration is traded off in favor of higher velocity upon detecting the electric motor in the electric vehicle is at an optimal angular-velocity for switching to an optimal lower torque constant and voltage constant. The total back electromotive force (BEMF) is prohibited from inhibiting further acceleration to a higher angular-velocity.
    Type: Grant
    Filed: March 1, 2013
    Date of Patent: March 31, 2015
    Assignee: International Business Machines Corporation
    Inventors: Allen K. Bates, Nhan X. Bui, Reed A. Hancock, Daniel J. Winarski
  • Patent number: 8982492
    Abstract: Provided are a method, system, and program for adjusting tension in a tape media to counter tape dimensional stability (TDS) errors in a tape media. A determination is made of whether to adjust tension of the tape media based on a detected error rate of reading at least one of the tracks. The tension of the tape media is adjusted in response to determining to adjust the tension.
    Type: Grant
    Filed: May 3, 2013
    Date of Patent: March 17, 2015
    Assignee: International Business Machines Corporation
    Inventors: Nhan X. Bui, Reed A. Hancock, Kevin B. Judd
  • Publication number: 20150069947
    Abstract: Dynamic reconfiguration-switching of motor windings is optimized between winding-configurations. Acceleration is traded off in favor of higher velocity upon detecting an electric motor is at an optimal angular-velocity for switching to an optimal lower torque constant and voltage constant. The total back electromotive force (BEMF) is prohibited from inhibiting further acceleration to a higher angular-velocity.
    Type: Application
    Filed: November 18, 2014
    Publication date: March 12, 2015
    Applicant: INTERNATIONAL BUSINESS MACHINES CORPORATION
    Inventors: Allen K. BATES, Nhan X. BUI, Reed A. HANCOCK, Daniel J. WINARSKI
  • Patent number: 8937777
    Abstract: In one embodiment, a method includes updating a standard deviation or a variance based on a current position error signal sample, where a smoothing factor applied to a subsequent calculation of the standard deviation or variance is dynamically altered based at least in part on whether a current value of the standard deviation or the variance is above or below a specified value. A determination is made as to whether the standard deviation or the variance exceeds a predetermined threshold. A stopwrite threshold is determined based on the standard deviation or the variance when the standard deviation or the variance exceeds the predetermined threshold. A determination is made as to whether the current position error signal sample exceeds the stopwrite threshold. Writing is disabled when the current position error signal sample exceeds the stopwrite threshold. Writing is enabled when the current position error signal sample does not exceed the stopwrite threshold.
    Type: Grant
    Filed: March 27, 2014
    Date of Patent: January 20, 2015
    Assignee: International Business Machines Corporation
    Inventors: Nhan X. Bui, Kevin B. Judd, Tomoko Taketomi
  • Publication number: 20150009590
    Abstract: Controlling the position of a head within a tape transport system. A track-follow control system (TFCS) includes a controller device for generating a control signal as a function of a position error signal (PES), wherein the PES indicates a difference between the actual and target positions of the head relative to the tape, and an actuator for changing the actual position. The TFCS is adapted to select a controller device configuration from a plurality of configurations dependent on an operating tape speed. The configurations are predetermined depending on a vibration frequency domain profile indicative of environmental vibrations induced to the head and tape to determine the control signal for adjusting an actuator output signal relative to a lateral tape motion signal. The TFCS is also adapted to feed-back a signal depending on a difference of the actuator output signal and the lateral tape motion signal to generate the PES.
    Type: Application
    Filed: June 26, 2014
    Publication date: January 8, 2015
    Inventors: Armando J. Argumedo, Nhan X. Bui, David H. Harper, Randy C. Inch, Kevin B. Judd, Mark A. Lantz, Angeliki Pantazi, Tomoko Taketomi
  • Patent number: 8896960
    Abstract: A servo track has servo pattern frames including two pairs of parallel transitions, the transitions of each pair spaced apart an equal distance, the first pair at an azimuth angle, the second pair at the opposite azimuth angle. A servo channel receives signals at first times corresponding to a servo read head detecting the transitions of the first pair of parallel transitions of a servo pattern frame, and second times corresponding to the servo read head detecting the transitions of the second pair of parallel transitions. The servo channel determines a relative lateral movement and velocity between the tape and the tape head based on respective functions of the ratio (TD?TC)/(TB?TA), distance d, and constants proportional to the azimuth angle and the trajectory angle.
    Type: Grant
    Filed: October 9, 2013
    Date of Patent: November 25, 2014
    Assignee: International Business Machines Corporation
    Inventors: Allen K. Bates, Nhan X. Bui, Nils Haustein, Stephen L. Schwartz, Daniel J. Winarski
  • Patent number: 8891198
    Abstract: In a method for operating a tape storage device comprising a tape head for reading and/or writing data from/to a tape in the tape storage device, a first tape skew value concerning a skew of the tape is determined and the first tape skew value is converted into a first skew control signal by means of a skew feedback controller. A second tape skew value concerning the skew of the tape is determined, and the second tape skew value is converted into a second skew control signal by a feed-forward controller. At least one compensation signal for the second skew control signal is determined, and at least one of a rotational orientation of the tape head and a tape motion direction of the tape is controlled dependent on the second skew control signal and the compensation signal in case the first skew control signal fails.
    Type: Grant
    Filed: July 22, 2013
    Date of Patent: November 18, 2014
    Assignee: International Business Machines Corporation
    Inventors: Nhan X. Bui, Giovanni Cherubini, Jens Jelitto, Angeliki Pantazi, Kazuhiro Tsuruta
  • Patent number: 8861324
    Abstract: A system, according to one embodiment, includes a tape drive configured to detect a telescoping condition of a magnetic recording tape and output an error alert when the telescoping condition is detected. Furthermore, a method, according to another embodiment, includes detecting a telescoping condition of a magnetic recording tape in use in a tape drive, and outputting an error alert when the telescoping condition is detected.
    Type: Grant
    Filed: June 27, 2013
    Date of Patent: October 14, 2014
    Assignee: International Business Machines Corporation
    Inventors: Nhan X. Bui, Ernest S. Gale, Reed A. Hancock, Randy C. Inch, Eiji Ogura
  • Publication number: 20140268409
    Abstract: Provided are a computer program product, system, and method for determining a skew error signal (SES) offset used to determine an SES to adjust heads in a drive unit. A determination is made of a first difference in a first orientation with respect to a direction of movement of the recordable storage media based on first and second position information read by first and second servo read elements on a first head. A determination is made of a second difference in a second orientation with respect to the direction of movement of the recordable storage media based on third and fourth position information read by the first servo read element and a third servo read element on a second head. An offset, calculated based on the determined first and second difference, is used to generate an error signal to adjust the first and second heads.
    Type: Application
    Filed: May 28, 2014
    Publication date: September 18, 2014
    Applicant: International Business Machines Corporation
    Inventors: Nhan X. Bui, Angeliki Pantazi, Tomoko Taketomi, Kazuhiro Tsuruta