Patents by Inventor Nhan Xuan Bui

Nhan Xuan 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: 11972783
    Abstract: In one general embodiment, a data storage product includes a magnetic recording tape having written thereon at least two servo tracks extending along a longitudinal axis of the tape. Each servo track has a timing-based servo (TBS) pattern comprising a series of servo frames arranged to enable lateral positioning of a magnetic head relative to the servo tracks as well as tape dimensional stability (TDS) compensation via head skew. Each frame comprises a sequence of pairs of leading and trailing servo stripes. Midpoints between the servo stripes in each pair, at all points having a same relative lateral height on the tape, are located along a virtual median line oriented at an angle ? from perpendicular to the longitudinal axis of the tape, the angle ? being greater than 1 degree.
    Type: Grant
    Filed: March 29, 2023
    Date of Patent: April 30, 2024
    Assignee: International Business Machines Corporation
    Inventors: Nhan Xuan Bui, Kevin Bruce Judd, Simeon Furrer, Mark Alfred Lantz
  • Publication number: 20230253011
    Abstract: In response to a rotation of timing-based servo (TBS) patterns of a first servo band and a second servo band, heights of top and bottom portions of servo stripes of servo frames of the TBS patterns are adjusted to compensate for changes in a usable height of the servo stripes caused by the rotation.
    Type: Application
    Filed: April 12, 2023
    Publication date: August 10, 2023
    Inventors: Nhan Xuan Bui, Mark Alfred Lantz, Simeon Furrer, Robert Biskeborn
  • Patent number: 11682423
    Abstract: In response to a rotation of timing-based servo (TBS) patterns of a first servo band and a second servo band, heights of top and bottom portions of servo stripes of servo frames of the TBS patterns are adjusted to compensate for changes in a usable height of the servo stripes caused by the rotation.
    Type: Grant
    Filed: October 1, 2020
    Date of Patent: June 20, 2023
    Assignee: INTERNATIONAL BUSINESS MACHINES CORPORATION
    Inventors: Nhan Xuan Bui, Mark Alfred Lantz, Simeon Furrer, Robert Biskeborn
  • Publication number: 20220108718
    Abstract: In response to a rotation of timing-based servo (TBS) patterns of a first servo band and a second servo band, heights of top and bottom portions of servo stripes of servo frames of the TBS patterns are adjusted to compensate for changes in a usable height of the servo stripes caused by the rotation.
    Type: Application
    Filed: October 1, 2020
    Publication date: April 7, 2022
    Inventors: Nhan Xuan Bui, Mark Alfred Lantz, Simeon Furrer, Robert Biskeborn
  • Patent number: 11145323
    Abstract: A computer-implemented method, according to one embodiment, includes: receiving a first timestamp in response to a first servo reader detecting a stripe of a first servo burst on the magnetic tape, and receiving a second timestamp in response to a second servo reader detecting a stripe of a second servo burst on the magnetic tape. A third timestamp is received in response to the first servo reader detecting a stripe of a third servo burst on the magnetic tape, while a fourth timestamp is received in response to the second servo reader detecting a stripe of a fourth servo burst on the magnetic tape. The first, second, third, and fourth timestamps are used to determine the skew of the magnetic tape. Further still, the first and third servo bursts are in a same first servo sub-frame, while the second and fourth servo bursts are in a same second servo sub-frame.
    Type: Grant
    Filed: November 30, 2020
    Date of Patent: October 12, 2021
    Assignee: International Business Machines Corporation
    Inventors: Nhan Xuan Bui, Simeon Furrer, Giovanni Cherubini, Mark Alfred Lantz
  • Patent number: 11011198
    Abstract: A tape drive may arrange timing-based-servo marks into a timing-based-servo pattern. The timing-based-servo pattern may be at least one M-pattern. The tape drive may select the at least one M-pattern. The tape drive may match at least two timing-based-servo marks in the at least one M-pattern. The tape drive may determine, from the matching, whether an alignment of the at least two timing-based-servo marks is demonstrative of tape-creep.
    Type: Grant
    Filed: October 29, 2019
    Date of Patent: May 18, 2021
    Assignee: International Business Machines Corporation
    Inventors: Daniel James Winarski, Nhan Xuan Bui, Lee Curtis Randall, Richard Bradshaw
  • Publication number: 20210125632
    Abstract: A tape drive may arrange timing-based-servo marks into a timing-based-servo pattern. The timing-based-servo pattern may be at least one M-pattern. The tape drive may select the at least one M-pattern. The tape drive may match at least two timing-based-servo marks in the at least one M-pattern. The tape drive may determine, from the matching, whether an alignment of the at least two timing-based-servo marks is demonstrative of tape-creep.
    Type: Application
    Filed: October 29, 2019
    Publication date: April 29, 2021
    Inventors: Daniel James Winarski, Nhan Xuan Bui, Lee Curtis Randall, Richard Bradshaw
  • Patent number: 10930309
    Abstract: A tape drive may calculate the slopes for three successive timing-based-servo marks in a timing-based-servo group. The timing-based-servo marks may be arranged in a one or more M-patterns. The three successive timing-based-servo marks may be across the one or more M-patterns. The tape drive may perform a parabolic fit of a gradient of the slopes. The tape drive may determine whether the gradient is demonstrative of tape-creep.
    Type: Grant
    Filed: October 29, 2019
    Date of Patent: February 23, 2021
    Assignee: International Business Machines Corporation
    Inventors: Daniel James Winarski, Nhan Xuan Bui, Lee Curtis Randall, Richard Bradshaw
  • Patent number: 10854236
    Abstract: At least one jack screw from a tape deck base may be removed. The tape deck base may be below a rigid support base that includes a rigid support shaft in the center of the rigid support base. A piezoelectric stack may be inserted where the at least one jack screw was removed from the tape deck base. The piezoelectric stack may tilt a tape guide roller bearing in a skew direction to improve the motion of tape in a tape path.
    Type: Grant
    Filed: September 11, 2019
    Date of Patent: December 1, 2020
    Assignee: International Business Machines Corporation
    Inventors: David Harper, Nhan Xuan Bui
  • Patent number: 10832715
    Abstract: A tape drive may calculate a slope for each of the timing-based-servo marks in a timing-based-servo group. The timing-based-servo marks are arranged in one or more M-patterns. The tape drive may average the slope for each of the timing-based-servo marks across the one or more M-patterns. The tape drive may generate a least-squares assessment of the averaged slope. The tape drive may determine, from the least-squares assessment, whether the averaged slope is demonstrative of tape-creep.
    Type: Grant
    Filed: October 29, 2019
    Date of Patent: November 10, 2020
    Assignee: International Business Machines Corporation
    Inventors: Daniel James Winarski, Nhan Xuan Bui, Lee Curtis Randall, Richard Bradshaw
  • Patent number: 9059658
    Abstract: An apparatus for controlling an electric motor is provided. A plurality of switches is provided for controlling a direction of current through motor coils of the electric motor. A brushless motor control circuit is connected to each of the plurality of switches. Responsive to a request to adjust one of an angular velocity and an angular acceleration of the electric motor, the plurality of switches are activated to place the motor coils in a predetermined configuration to maximize torque or reduce a total back electromotive force (BEMF) from the motor coils.
    Type: Grant
    Filed: September 2, 2008
    Date of Patent: June 16, 2015
    Assignee: INTERNATIONAL BUSINESS MACHINES CORPORATION
    Inventors: Allen Keith Bates, Nhan Xuan Bui, Reed Alan Hancock, Wayne Isami Imaino, Daniel James Winarski
  • Patent number: 8988031
    Abstract: A calculation function, which optimizes a dynamic reconfiguration-switching of motor windings between winding-configurations, is dynamically configured. Acceleration is traded off in favor of higher velocity upon detecting the 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: Grant
    Filed: September 13, 2012
    Date of Patent: March 24, 2015
    Assignee: International Business Machines Corporation
    Inventors: Allen Keith Bates, Nhan Xuan Bui, Reed Alan Hancock, Daniel James Winarski
  • Patent number: 8981696
    Abstract: Dynamic reconfiguration-switching of motor windings in an electric motor in an electric vehicle is optimized between winding-configurations. 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: September 13, 2012
    Date of Patent: March 17, 2015
    Assignee: International Business Machines Corporation
    Inventors: Allen Keith Bates, Nhan Xuan Bui, Reed Alan Hancock, Daniel James Winarski
  • Patent number: 8981695
    Abstract: Dynamic reconfiguration-switching of motor windings is optimized between winding-configurations. Acceleration is traded off in favor of higher velocity upon detecting a brushless DC 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: Grant
    Filed: September 13, 2012
    Date of Patent: March 17, 2015
    Assignee: International Business Machines Corporation
    Inventors: Allen Keith Bates, Nhan Xuan Bui, Reed Alan Hancock, Daniel James Winarski
  • Patent number: 8963469
    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: Grant
    Filed: September 13, 2012
    Date of Patent: February 24, 2015
    Assignee: International Business Machines Corporation
    Inventors: Allen Keith Bates, Nhan Xuan Bui, Reed Alan Hancock, Daniel James Winarski
  • Patent number: 8963463
    Abstract: Dynamic reconfiguration-switching of motor windings is optimized between winding-configurations. Acceleration is traded off in favor of higher velocity upon detecting a tape storage drive 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: September 13, 2012
    Date of Patent: February 24, 2015
    Assignee: International Business Machines Corporation
    Inventors: Allen Keith Bates, Nhan Xuan Bui, Reed Alan Hancock, Daniel James Winarski
  • Patent number: 8902531
    Abstract: A maximum velocity is dynamically determined during a tape drive operation to obtain a statistical standard deviation of a position error signal (PES) that yields an amount of stopwrite (SW) operations that avoids backhitching. The tape velocity is adjusted to the maximum velocity.
    Type: Grant
    Filed: August 28, 2012
    Date of Patent: December 2, 2014
    Assignee: International Business Machines Corporation
    Inventors: Nhan Xuan Bui, Kevin Bruce Judd, Roger Javier Justo, Hirokazu Nakayama, Tomoko Taketomi
  • Patent number: 8749922
    Abstract: A tape movement constraint for a tape drive system, comprises a tiltable tape roller bearing having a grooved surface adapted to contact and engage a surface of the tape as the roller barrel rotates, and an actuator adapted to pivot the roller bearing surface when the actuator is actuated, to control the lateral position of a tape. In operation, in one embodiment, a roller barrel of the tiltable roller bearing is biased in a first position on a pivot axis, using magnetic attraction between a movable magnet and a return path structure of magnetically permeable material. The roller barrel is pivoted on the pivot axis by conducting current through a fixed coil to generate a magnetic field which is conducted by the return path structure to interact with the magnetic field of the magnet. Other embodiments are described and claimed.
    Type: Grant
    Filed: July 23, 2012
    Date of Patent: June 10, 2014
    Assignee: International Business Machines Corporation
    Inventors: Armando Jesus Argumedo, Nhan Xuan Bui, William Marvin Dyer, Reed Alan Hancock, David Howard Flores Harper, Wayne Isami Imaino, Kevin Bruce Judd
  • Patent number: 8743508
    Abstract: A tape movement constraint for a tape drive system, comprises a tiltable tape roller bearing having a grooved surface adapted to contact and engage a surface of the tape as the roller barrel rotates, and an actuator adapted to pivot the roller bearing surface when the actuator is actuated, to control the lateral position of a tape. In operation, in one embodiment, a roller barrel of the tiltable roller bearing is biased in a first position on a pivot axis, using magnetic attraction between a movable magnet and a return path structure of magnetically permeable material. The roller barrel is pivoted on the pivot axis by conducting current through a fixed coil to generate a magnetic field which is conducted by the return path structure to interact with the magnetic field of the magnet. Other embodiments are described and claimed.
    Type: Grant
    Filed: July 23, 2012
    Date of Patent: June 3, 2014
    Assignee: International Business Machines Corporation
    Inventors: Armando Jesus Argumedo, Nhan Xuan Bui, William Marvin Dyer, Reed Alan Hancock, David Howard Flores Harper, Wayne Isami Imaino, Kevin Bruce Judd
  • Patent number: 8711511
    Abstract: A tape drive configured to accurately position a head actuator in the presence of physical disturbances is disclosed. The tape drive includes a track-follow controller to position a head actuator over data tracks on magnetic tape. The tape drive further includes a disturbance observer configured to estimate a vibration disturbance and output a compensation signal to assist the track-follow controller to accurately position the head actuator over the data tracks in the presence of vibration. When estimating the vibration disturbance, the disturbance observer takes into account vibration frequency characteristics, such as frequency characteristics derived from a vibration specification associated with the tape drive, or frequency characteristics derived from known vibration disturbances experienced by the tape drive. A corresponding method is also disclosed.
    Type: Grant
    Filed: June 19, 2012
    Date of Patent: April 29, 2014
    Assignee: International Business Machines Corporation
    Inventors: Angeliki Pantazi, Nhan Xuan Bui, Jens Jelitto