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).
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Patent number: 8577043Abstract: An encryption communications appliance provides data encryption management for a data storage library. The appliance is coupled to an encryption-capable storage device, a data storage library controller within the data storage library and with an encryption key manager (EKM). The encryption command communications appliance intercepts encryption key requests from the data storage device and transparently forwards the requests to the EKM. The appliance also forwards transparently communications between the library controller and the data storage device.Type: GrantFiled: January 9, 2009Date of Patent: November 5, 2013Assignee: International Business Machines CorporationInventors: Allen K. Bates, Nhan X. Bui, Brian G. Goodman, Daniel J. Winarski
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Publication number: 20130286503Abstract: A method according to one embodiment includes detecting a signal originating from at least one reader of a first outer module of a head as a tape passes thereacross, the head having at least the first outer module and a second outer modules positioned on opposite sides of an inner module and aligned with the inner module in a direction of tape travel thereacross. A first guide positioned in front of the first outer module is moved in a direction towards the tape until the signal detected by the first outer module decreases. The first guide is moved in a direction away from the tape to a position to set about a predetermined wrap angle of the tape relative to the first outer module after the signal detected by the first outer module decreases.Type: ApplicationFiled: June 26, 2013Publication date: October 31, 2013Inventors: Nhan X. Bui, Ernest S. Gale, Reed A. Hancock, Kazuhiro Tsuruta
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Publication number: 20130265671Abstract: A servo system according to one embodiment includes a servo control configured to: determine position error between a magnetic head and a desired position related to at least one defined servo track on a longitudinal tape based on at least one servo signal; calculate a first average position of the magnetic head while the longitudinal tape is moved in a first direction; calculate a first offset of the magnetic head while the longitudinal tape is moved in the first direction based on a target position and an assumption that the first average position of the magnetic head occurred when the tape was at a top-most position or a bottom-most position of a supply reel; and operate an actuator to position the actuator substantially at the target position using the first offset and the first average positionType: ApplicationFiled: June 4, 2013Publication date: October 10, 2013Inventors: Nhan X. Bui, Reed A. Hancock, Randy C. Inch
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Publication number: 20130229136Abstract: 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: ApplicationFiled: March 1, 2013Publication date: September 5, 2013Applicant: International Business Machines CorporationInventors: Allen K. BATES, Nhan X. BUI, Reed A. HANCOCK, Daniel J. WINARSKI
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Patent number: 8526134Abstract: A servo system according to one embodiment includes at least one servo sensor for sensing a lateral position of a magnetic head with respect to at least one defined servo track of a longitudinal tape; a fine actuator configured to translate the magnetic head laterally with respect to the longitudinal tape; a coarse actuator configured to translate the fine actuator laterally with respect to the longitudinal tape; and a servo control. The servo control is configured to perform various operations that may be used to estimate a midpoint of lateral tape excursion of a flangeless tape path for calibrating a tape drive. Additional systems are also presented.Type: GrantFiled: June 2, 2011Date of Patent: September 3, 2013Assignee: International Business Machines CorporationInventors: Nhan X. Bui, Reed A. Hancock, Randy C. Inch
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Patent number: 8520332Abstract: In one embodiment, a method includes sensing a servo sensor while a longitudinal tape is moved past a magnetic head, determining position error between the magnetic head and a desired position related to the at least one defined servo track; providing signals to operate a fine actuator to translate the magnetic head laterally in a manner to reduce the determined position error; transitioning from a write state to a monitor state when the determined position error is greater than a threshold error value; transitioning from the monitor state to a stop write state when the determined position error is greater than the threshold error value for a first predetermined period; and transitioning from the monitor state to the write state when the determined position error is less than the threshold error value for a second predetermined period.Type: GrantFiled: May 30, 2012Date of Patent: August 27, 2013Assignee: International Business Machines CorporationInventors: Nhan X. Bui, Reed A. Hancock, Tomoko Taketomi
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Patent number: 8493682Abstract: According to one embodiment, a method includes tracking a magnetic tape moving in a first direction using at least one reader of an inner module of a head having at least the inner module and first and second outer modules positioned on opposite sides of the inner module and aligned with the inner module in a tape travel direction, detecting a signal using at least one reader of the first outer module as the tape passes thereacross, moving a guide positioned in front of the first outer module in a direction towards the tape until the signal detected by the first outer module decreases by a predetermined amount, and moving the guide directionally away from the tape to a position to set about a predetermined wrap angle of the tape relative to the first outer module after the signal detected by the first outer module decreases by the predetermined amount.Type: GrantFiled: May 25, 2011Date of Patent: July 23, 2013Assignee: International Business Machines CorporationInventors: Nhan X. Bui, Ernest S. Gale, Reed A. Hancock, Kazuhiro Tsuruta
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Patent number: 8446684Abstract: According to one embodiment, a magnetic recording tape includes a plurality of servo tracks, each servo track comprising a series of magnetically defined bars having an average height of between about 80 microns and about 120 microns, wherein an average stripe angle of the bars is between about 10° and about 25°. A stripe angle is measured between a longitudinal axis of each respective bar and a line oriented perpendicular to a direction of tape travel and parallel to a plane of the tape, wherein an average stripe width of the bars is between about 1.0 micron and about 2.2 microns and an average servo frame length of groups of the bars comprising a servo frame is between about 120 microns and about 180 microns. In more embodiments, a servo format and a system including a servo format are disclosed, along with other embodiments of magnetic tapes.Type: GrantFiled: January 21, 2010Date of Patent: May 21, 2013Assignee: International Business Machines CorporationInventors: Nhan X. Bui, Giovanni Cherubini, Evangelos S. Eleftheriou, Reed A. Hancock, Robert A. Hutchins
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Publication number: 20130063836Abstract: A magnetic tape drive has a drive system to move a magnetic tape longitudinally; servo head(s) for reading servo band information from a magnetic tape as the magnetic tape is moved longitudinally; a magnetic tape read write head configured to read and to write the magnetic tape, having a data write width (w) greater than a normal shingled track pitch width (p) of the magnetic tape; an actuator system for positioning the read write head laterally; and a control. The magnetic tape drive stores an overwrite erase format of non-shingled track pitch longitudinal pattern(s) whose pitch is greater than the normal shingled track pitch width (p); and, the control, in response to activation of overwrite erasure of the tape drive, operates the actuator system and the magnetic tape read write head to write non-data to magnetic tape in the stored overwrite erase format.Type: ApplicationFiled: September 9, 2011Publication date: March 14, 2013Applicant: INTERNATIONAL BUSINESS MACHINES CORPORATIONInventors: NHAN X. BUI, EDWIN R. CHILDERS, REED A. HANCOCK
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Patent number: 8395860Abstract: A method to position a head module, where the head module comprises at least one servo element and a plurality of data elements, where the servo element and each of the plurality of data elements can detect a servo signal, wherein the method includes moving a sequential information storage medium having a servo band encoded therein across the head module and detecting the servo band using the at least one servo element or any one of the plurality of data elements.Type: GrantFiled: April 30, 2012Date of Patent: March 12, 2013Assignee: International Business Machines CorporationInventors: Nhan X. Bui, Giovanni Cherubini, Robert A. Hutchins, Jens Jelitto, Kazuhiro Tsuruta
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Publication number: 20120307390Abstract: In one embodiment, a tape drive system includes a magnetic head having at least one servo sensor for track-following at least one defined servo track of a longitudinal tape, a tape motion controller configured to move the longitudinal tape past the magnetic head, a compound actuator configured to translate the magnetic head laterally with respect to the longitudinal tape, and a control configured to track-follow the at least one defined servo track by reducing a position error between the magnetic head and a desired position, transition from a write state to a monitor state when the position error is greater than a threshold, transition from the monitor state to a stop write state when the position error is greater than the threshold for a first period, and transition from the monitor state to the write state when the position error is less than the threshold for a second period.Type: ApplicationFiled: June 2, 2011Publication date: December 6, 2012Applicant: INTERNATIONAL BUSINESS MACHINES CORPORATIONInventors: Nhan X. Bui, Reed A. Hancock, Tomoko Taketomi
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Publication number: 20120307402Abstract: According to one embodiment, a method includes sensing a first servo sensor while a longitudinal tape is moved in a first direction; determining position error between the magnetic head and a desired position related to the at least one defined servo track; providing signals to operate a fine actuator to translate the magnetic head laterally in a manner to reduce the determined position error; calculating a first average position of the magnetic head for at least one first run-out cycle while the longitudinal tape is moved in the first direction; calculating a first offset of the magnetic head while the longitudinal tape is moved in the first direction; operating a coarse actuator to position the coarse actuator substantially at a target position using the first offset and the first average position.Type: ApplicationFiled: May 30, 2012Publication date: December 6, 2012Applicant: International Business Machines CorporationInventors: Nhan X. Bui, Reed A. Hancock, Randy C. Inch
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Publication number: 20120307391Abstract: A tape drive system according to one embodiment includes a magnetic head having at least one servo sensor; a tape motion controller; a fine actuator; a skew actuator; a coarse actuator; and a control. The control is configured to perform various operations that help account for vibrations that effect track-following a servo track when operating a tape drive. Additional systems, methods and computer program products are also described.Type: ApplicationFiled: June 2, 2011Publication date: December 6, 2012Applicant: INTERNATIONAL BUSINESS MACHINES CORPORATIONInventors: Nhan X. Bui, Reed A. Hancock, Tomoko Taketomi
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Publication number: 20120307392Abstract: In one embodiment, a method includes sensing a servo sensor while a longitudinal tape is moved past a magnetic head, determining position error between the magnetic head and a desired position related to the at least one defined servo track; providing signals to operate a fine actuator to translate the magnetic head laterally in a manner to reduce the determined position error; transitioning from a write state to a monitor state when the determined position error is greater than a threshold error value; transitioning from the monitor state to a stop write state when the determined position error is greater than the threshold error value for a first predetermined period; and transitioning from the monitor state to the write state when the determined position error is less than the threshold error value for a second predetermined period.Type: ApplicationFiled: May 30, 2012Publication date: December 6, 2012Applicant: International Business Machines CorporationInventors: Nhan X. Bui, Reed A. Hancock, Tomoko Taketomi
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Publication number: 20120307401Abstract: A servo system according to one embodiment includes at least one servo sensor for sensing a lateral position of a magnetic head with respect to at least one defined servo track of a longitudinal tape; a fine actuator configured to translate the magnetic head laterally with respect to the longitudinal tape; a coarse actuator configured to translate the fine actuator laterally with respect to the longitudinal tape; and a servo control. The servo control is configured to perform various operations that may be used to estimate a midpoint of lateral tape excursion of a flangeless tape path for calibrating a tape drive. Additional systems are also presented.Type: ApplicationFiled: June 2, 2011Publication date: December 6, 2012Applicant: INTERNATIONAL BUSINESS MACHINES CORPORATIONInventors: Nhan X. Bui, Reed A. Hancock, Randy C. Inch
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Publication number: 20120300337Abstract: According to one embodiment, a method includes tracking a magnetic tape moving in a first direction using at least one reader of an inner module of a head having at least the inner module and first and second outer modules positioned on opposite sides of the inner module and aligned with the inner module in a tape travel direction, detecting a signal using at least one reader of the first outer module as the tape passes thereacross, moving a guide positioned in front of the first outer module in a direction towards the tape until the signal detected by the first outer module decreases by a predetermined amount, and moving the guide directionally away from the tape to a position to set about a predetermined wrap angle of the tape relative to the first outer module after the signal detected by the first outer module decreases by the predetermined amount.Type: ApplicationFiled: May 25, 2011Publication date: November 29, 2012Applicant: INTERNATIONAL BUSINESS MACHINES CORPORATIONInventors: Nhan X. Bui, Ernest S. Gale, Reed A. Hancock, Kazuhiro Tsuruta
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Patent number: 8213105Abstract: Various embodiments for addressing time-varying periodic disturbances in a servo control system are provided. Each of a plurality of coefficients is updated based on an estimation of at least one disturbance frequency. The updated plurality of coefficients is provided to at least one peak filter modifying an input signal of the servo control system. The peak filter is operable in view of the updated plurality of coefficients to cancel at least one of the time-varying periodic disturbances.Type: GrantFiled: November 5, 2009Date of Patent: July 3, 2012Assignee: International Business Machines CorporationInventors: Nhan X. Bui, Evangelos S. Eleftheriou, Jens Jelitto, Angeliki Pantazi
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Patent number: 8139302Abstract: A system and method are disclosed for detecting a periodic sequence. A value detector module detects a plurality of values of a periodic sequence. In one embodiment, a transformation module transforms the plurality of values into transformed values. A confinement module confines the values to a limited set of confined values. A correlation module correlates the confined values with a plurality of instances of the periodic sequence. In addition, a selection module selects an instance of the periodic sequence with the highest correlation to the confined values as an observed periodic sequence.Type: GrantFiled: June 14, 2010Date of Patent: March 20, 2012Assignee: International Business Machines CorporationInventors: Nhan X. Bui, Roy D. Cideciyan, Robert A. Hutchins, Thomas Mittelholzer, Kazuhiro Tsuruta
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Patent number: 8094402Abstract: Magnetic tape devices encounter read and/or write errors when the tape is not being passed across the head with the proper tension and/or skew angle. According to one embodiment, a system which corrects for these problems comprises a head having an array of at least one of readers and writers, a drive mechanism for passing a magnetic recording tape over the head, a skew-inducing mechanism coupled to the head for adjusting a skew angle of a longitudinal axis of the array relative to a direction normal to a direction of tape travel over the head, and a controller in communication with the head. The system also determines a tape dimensional stability state of the tape and adjust the skew angle away from normal to the direction of tape travel and lowers a tension of the tape across the head if the tape dimensional stability state is in a contracted state.Type: GrantFiled: January 12, 2010Date of Patent: January 10, 2012Assignee: International Business Machines CorporationInventors: Nhan X. Bui, Edwin R. Childers, Eric R. Christensen, Reed A. Hancock, Diana J. Hellman
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Publication number: 20110273793Abstract: In a magnetic tape drive having a servo read system with at least one read head, the system configured to read servo pattern information as a magnetic tape is moved longitudinally with respect to the at least one read head, the servo pattern comprising a timing-based servo pattern comprising an even number of bursts of sloped magnetic stripes, adjacent bursts oppositely sloped, alternate bursts identically sloped, an embodiment of a method determines the time between detection from the read head of a same stripe of alternate bursts of a pattern; determines the time between detection from the read head of stripes of a burst of a pattern; and determines a ratio of the determined times. The ratio is compared to a threshold, wherein the threshold comprises a differentiation between different servo pattern types.Type: ApplicationFiled: May 10, 2010Publication date: November 10, 2011Applicant: INTERNATIONAL BUSINESS MACHINES CORPORATIONInventors: NHAN X. BUI, GIOVANNI CHERUBINI, JENS JELITTO, KAZUHIRO TSURUTA