Patents by Inventor Tomoko Taketomi
Tomoko Taketomi 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: 9741380Abstract: In one embodiment, a computer-implemented method includes creating a spike in a servo channel from a predetermined start position to an end position, and storing servo data including at least a portion thereof generated during the spike. The spike has a predetermined amplitude. In another embodiment, a computer program product includes a computer readable storage medium having program instructions embodied therewith. The program instructions are executable by a controller to perform the foregoing method.Type: GrantFiled: February 8, 2017Date of Patent: August 22, 2017Assignee: International Business Machines CorporationInventors: Nhan X. Bui, Eiji Ogura, Tomoko Taketomi, Kazuhiro Tsuruta
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Patent number: 9685180Abstract: A computer program product for positioning an actuator, according to one embodiment, includes a computer readable storage medium having program instructions embodied therewith. The computer readable storage medium is not a transitory signal per se. The program instructions are executable by a processing circuit to cause the processing circuit to perform a method that includes generating or receiving, by the processing circuit, a first value representative of a lateral position of a tape, and using, by the processing circuit, the first value to adjust a position of a coarse actuator for moving a magnetic head in response to determining that the first value is in a first range relative to a first threshold. An integrator value is used by the processing circuit to adjust the position of the coarse actuator in response to determining that the first value is in a second range relative to the first threshold.Type: GrantFiled: March 10, 2016Date of Patent: June 20, 2017Assignee: International Business Machines CorporationInventors: Nhan X. Bui, Angeliki Pantazi, Tomoko Taketomi
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Patent number: 9640209Abstract: In one embodiment, a computer-implemented method for simulating a defect signal in a time based servo system includes determining a start position for a spike, determining an end position for the spike, determining a servo channel, determining an amplitude of the spike, initiating an acquire lock process, creating the spike in the determined servo channel from the determined start position to the determined end position, and storing servo data including at least a portion thereof generated during the spike. The spike has the determined amplitude. In another embodiment, a computer program product for generating defect signals in a storage system includes a computer readable storage medium having program instructions embodied therewith, wherein the computer readable storage medium is not a transitory signal per se. The program instructions are executable by a controller to perform the foregoing method.Type: GrantFiled: September 20, 2016Date of Patent: May 2, 2017Assignee: International Business Machines CorporationInventors: Nhan X. Bui, Eiji Ogura, Tomoko Taketomi, Kazuhiro Tsuruta
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Patent number: 9626994Abstract: A method according to one embodiment includes generating track following controller state information based on a positional signal of a head relative to a medium. One or more portions of the state information corresponding to particular frequencies are used to determine at least one of: lateral tape movement, tape skew, vibration operation conditions, and roller performance.Type: GrantFiled: September 4, 2015Date of Patent: April 18, 2017Assignee: International Business Machines CorporationInventors: Nhan X. Bui, Angeliki Pantazi, Tomoko Taketomi
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Patent number: 9564160Abstract: Methods, systems, and computer program product embodiments for improving track-follow control in a tape storage system, by a processor device, are provided. In one embodiment, a method comprises, using an accelerometer to dynamically detect device vibration for determining whether to implement a vibration compensation control mechanism.Type: GrantFiled: July 24, 2015Date of Patent: February 7, 2017Assignee: INTERNATIONAL BUSINESS MACHINES CORPORATIONInventors: Nhan X. Bui, Angeliki Pantazi, Tomoko Taketomi
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Publication number: 20170032817Abstract: In one general embodiment, a method includes calculating a differential position value based on readback signals from at least two servo readers of a magnetic head reading servo tracks of a magnetic recording tape. The differential position value is compared to a previously-calculated differential position value. An action is performed in response to determining that the difference between the differential position value and the previously-calculated differential position value is in a predefined range. In another general embodiment, an apparatus includes a magnetic head having at least two servo readers, and a controller in communication with the servo readers. The controller is configured to detect a sudden change in a width of a magnetic recording tape based on a differential position value derived from relatively more current servo readback data and a second differential position value derived from relatively older servo readback data.Type: ApplicationFiled: July 31, 2015Publication date: February 2, 2017Inventors: Nhan X. Bui, Randy C. Inch, David L. Swanson, Tomoko Taketomi
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Publication number: 20170025138Abstract: Methods, systems, and computer program product embodiments for improving track-follow control in a tape storage system, by a processor device, are provided. In one embodiment, a method comprises, using an accelerometer to dynamically detect device vibration for determining whether to implement a vibration compensation control mechanism.Type: ApplicationFiled: July 24, 2015Publication date: January 26, 2017Applicant: INTERNATIONAL BUSINESS MACHINES CORPORATIONInventors: Nhan X. BUI, Angeliki PANTAZI, Tomoko TAKETOMI
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Patent number: 9548080Abstract: Methods, systems, and computer program product embodiments for improving track-follow control in a tape storage system, by a processor device, are provided. In one embodiment, a method comprises, time-varying filtering an error feedback signal within a closed-loop tape controller to dampen varying motor and harmonic disturbances.Type: GrantFiled: June 18, 2015Date of Patent: January 17, 2017Assignee: INTERNATIONAL BUSINESS MACHINES CORPORATIONInventors: Nhan X. Bui, Angeliki Pantazi, Tomoko Taketomi
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Publication number: 20160372150Abstract: Methods, systems, and computer program product embodiments for improving track-follow control in a tape storage system, by a processor device, are provided. In one embodiment, a method comprises, time-varying filtering an error feedback signal within a closed-loop tape controller to dampen varying motor and harmonic disturbances.Type: ApplicationFiled: June 18, 2015Publication date: December 22, 2016Applicant: INTERNATIONAL BUSINESS MACHINES CORPORATIONInventors: Nhan X. BUI, Angeliki PANTAZI, Tomoko TAKETOMI
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Patent number: 9477411Abstract: To provide a technique for optimizing the processing order of recall requests in which the average latency time of a host apparatus is minimized. A storage manager accepts a request of the host apparatus for the recalling data from a tape library, and stores the request in a queue table. In response to storage of the request, the storage manager calculates the latency time for each request in all the conceivable execution orders for all the requests stored in the queue table. The storage manager determines the execution order which minimizes the total calculated latency time for all the requests including the active request.Type: GrantFiled: July 15, 2015Date of Patent: October 25, 2016Assignee: INTERNATIONAL BUSINESS MACHINES CORPORATIONInventors: Norie Iwasaki, Yutaka Oishi, Tomoko Taketomi, Kazuhiro Tsuruta
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Patent number: 9472236Abstract: Methods, systems, and computer program product embodiments for improving track-follow control in a tape storage system using a time-varying filter, by a processor device, are provided. In one embodiment, a method comprises, dynamically updating coefficients used to determine parameters of the time-varying filter based upon a reel radius and a reel rotation to reduce computation delay.Type: GrantFiled: July 24, 2015Date of Patent: October 18, 2016Assignee: INTERNATIONAL BUSINESS MACHINES CORPORATIONInventors: Nhan X. Bui, Angeliki Pantazi, Tomoko Taketomi
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Patent number: 9424869Abstract: 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: GrantFiled: July 17, 2015Date of Patent: August 23, 2016Assignee: INTERNATIONAL BUSINESS MACHINES CORPORATIONInventors: Armando J. Argumedo, Nhan X. Bui, David H. Harper, Randy C. Inch, Kevin B. Judd, Mark A. Lantz, Angeliki Pantazi, Tomoko Taketomi
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Publication number: 20160196845Abstract: A computer program product for positioning an actuator, according to one embodiment, includes a computer readable storage medium having program instructions embodied therewith. The computer readable storage medium is not a transitory signal per se. The program instructions are executable by a processing circuit to cause the processing circuit to perform a method that includes generating or receiving, by the processing circuit, a first value representative of a lateral position of a tape, and using, by the processing circuit, the first value to adjust a position of a coarse actuator for moving a magnetic head in response to determining that the first value is in a first range relative to a first threshold. An integrator value is used by the processing circuit to adjust the position of the coarse actuator in response to determining that the first value is in a second range relative to the first threshold.Type: ApplicationFiled: March 10, 2016Publication date: July 7, 2016Inventors: Nhan X. Bui, Angeliki Pantazi, Tomoko Taketomi
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Patent number: 9361928Abstract: 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: GrantFiled: December 7, 2015Date of Patent: June 7, 2016Assignee: INTERNATIONAL BUSINESS MACHINES CORPORATIONInventors: Nhan X. Bui, Kevin B. Judd, Roger J. Justo, Hirokazu Nakayama, Tomoko Taketomi
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Patent number: 9318138Abstract: A controller, according to one embodiment, has at least some hardware components, and is configured to determine an offset between adjacent arrays of transducers in a direction perpendicular to an intended direction of media travel when a magnetic head having the arrays is positioned at a first position, cause the magnetic head to tilt to a second position, and delay write operations performed by at least some of the transducers in a first of the arrays such that data written by the transducers in the first array is readable by a second array of read transducers aligned in the direction orthogonal to the intended direction of media travel without implementing readback delays corresponding to the write delays.Type: GrantFiled: December 17, 2014Date of Patent: April 19, 2016Assignee: International Business Machines CorporationInventors: Nhan X. Bui, Tomoko Taketomi, Keisuke Tanaka, Kazuhiro Tsuruta
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Patent number: 9299373Abstract: 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: GrantFiled: March 3, 2015Date of Patent: March 29, 2016Assignee: International Business Machines CorporationInventors: Nhan X. Bui, Angeliki Pantazi, Tomoko Taketomi
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Publication number: 20160086629Abstract: 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: ApplicationFiled: December 7, 2015Publication date: March 24, 2016Applicant: INTERNATIONAL BUSINESS MACHINES CORPORATIONInventors: Nhan X. BUI, Kevin B. JUDD, Roger J. JUSTO, Hirokazu NAKAYAMA, Tomoko TAKETOMI
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Patent number: 9263065Abstract: 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: GrantFiled: December 8, 2014Date of Patent: February 16, 2016Assignee: International Business Machines CorporationInventors: Nhan X. Bui, Kevin B. Judd, Tomoko Taketomi
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Patent number: 9251840Abstract: 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: GrantFiled: October 3, 2014Date of Patent: February 2, 2016Assignee: INTERNATIONAL BUSINESS MACHINES CORPORATIONInventors: Nhan X. Bui, Kevin B. Judd, Roger J. Justo, Hirokazu Nakayama, Tomoko Taketomi
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Publication number: 20160019921Abstract: A controller, according to one embodiment, has at least some hardware components, and is configured to determine an offset between adjacent arrays of transducers in a direction perpendicular to an intended direction of media travel when a magnetic head having the arrays is positioned at a first position, cause the magnetic head to tilt to a second position, and delay write operations performed by at least some of the transducers in a first of the arrays such that data written by the transducers in the first array is readable by a second array of read transducers aligned in the direction orthogonal to the intended direction of media travel without implementing readback delays corresponding to the write delays.Type: ApplicationFiled: December 17, 2014Publication date: January 21, 2016Inventors: Nhan X. Bui, Tomoko Taketomi, Keisuke Tanaka, Kazuhiro Tsuruta