Patents by Inventor Kazuhiko Takaishi
Kazuhiko Takaishi 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: 8068307Abstract: According to one embodiment, a position control apparatus includes: a digital control module that performs position control including disturbance adaptive control with a predetermined sampling period with the use of a control constant, in accordance with a position error between a target position and a current position of the object; and a table that stores the control constant corresponding to a value of sin(?T/2), wherein the digital control module determines a control value of the actuator in accordance with the position error, calculates the value of sin(?T/2) according to an adaptive law from a signal based on the position error, reads the corresponding control constant from the table in accordance with the calculated value of sin(?T/2), and updates the control constant.Type: GrantFiled: September 24, 2009Date of Patent: November 29, 2011Assignee: Toshiba Storage Device CorporationInventor: Kazuhiko Takaishi
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Patent number: 8049987Abstract: According to one embodiment, a position control apparatus includes: a digital control module that performs position control including disturbance adaptive control with a predetermined sampling period using a control constant, in accordance with a position error between a target position and a current position of the object; and a table that stores the control constant corresponding to a value of sin(?T) or cos(?T), wherein the digital control module is configured to determine a control value of the actuator in accordance with the position error, calculates the value of sin(?T) or cos(?T) according to an adaptive law from a signal based on the position error, reads the corresponding control constant from the table in accordance with the calculated value of sin(?T) or cos(?T), and updates the control constant, to perform the position control including the disturbance adaptive control.Type: GrantFiled: September 24, 2009Date of Patent: November 1, 2011Assignee: Toshiba Storage Device CorporationInventor: Kazuhiko Takaishi
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Patent number: 8023222Abstract: According to one embodiment, an information storage device includes a recording/reproducing head, a positioning controller, a position detector, a storage module, and a position error detector. The position detector detects the position of the recording/reproducing head. The storage module stores servo control filters. The position error detector generates a new position error signal from a target position and the position of the recording/reproducing head when the positioning controller performs positioning control with control current obtained from a position error signal having passed through each servo control filter. Upon occurrence of a recording/reproducing error, learning to calculate a vibration amount from the position of the recording/reproducing head is sequentially performed for the servo control filters for a predetermined time.Type: GrantFiled: September 28, 2009Date of Patent: September 20, 2011Assignee: Toshiba Storage Device CorporationInventors: Takeshi Hara, Kazuhiko Takaishi
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Patent number: 8009382Abstract: According to one embodiment, a position control apparatus includes: a digital control module that performs position control including disturbance adaptive control with a predetermined sampling period using a control constant, in accordance with a position error; and a table that stores the control constant corresponding to one of values sin(?T), cos(?T), and sin(?T/2), wherein the digital control module determines a control value of the actuator in accordance with the position error, calculates a value of one of estimated errors of sin(?T), cos(?T), and sin(?T/2) according to an adaptive law from a signal based on the position error, multiplies the calculated estimated error by an adaptive gain in accordance with a value of the angular frequency ?, updates one of the values, reads the corresponding control constant from the table based on the updated value, and updates the control constant.Type: GrantFiled: September 23, 2009Date of Patent: August 30, 2011Assignee: Toshiba Storage Device CorporationInventor: Kazuhiko Takaishi
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Patent number: 7953502Abstract: In a position control device having a disturbance suppression function, loop gain is calibrated without stopping disturbance suppression control. The position control device has, for disturbance suppression control, a feedback controller for changing the loop characteristic, a table for storing a target gain according to a disturbance frequency, and a gain calibration section for calibrating open loop gain. The gain is calibrated using a target gain in the table according to the change of the loop characteristic of the feedback controller. Open loop gain can be calibrated without interrupting the disturbance suppression control, so the open loop gain can be accurately calibrated without being affected by disturbance, and accurate position control is possible.Type: GrantFiled: June 25, 2010Date of Patent: May 31, 2011Assignee: Toshiba Storage Device CorporationInventor: Kazuhiko Takaishi
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Patent number: 7948698Abstract: A pattern transfer apparatus includes a storage-medium-surface detecting unit that detects a foreign substance or defect on a surface of a storage medium and specifies a position and a size of the foreign substance or defect; a relative-position adjusting unit that adjusts a relative position on a contact surface between the surface of the storage medium and a transfer pattern surface of a transfer master, and a relative-position-adjustment instructing unit that calculates an adjusted value of the relative position according to a detection result, and instructs the relative-position adjusting unit to adjust the relative position based on the adjusted value.Type: GrantFiled: March 5, 2009Date of Patent: May 24, 2011Assignee: Toshiba Storage Device CorporationInventors: Kazuhiko Takaishi, Masanori Fukushi
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Patent number: 7869156Abstract: 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: GrantFiled: April 9, 2009Date of Patent: January 11, 2011Assignee: Toshiba Storage Device CorporationInventor: Kazuhiko Takaishi
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Publication number: 20100328804Abstract: According to one embodiment, a magnetic disk storage device includes a magnetic disk, a head, a clock generator, an estimating module, and a controller. The magnetic disk includes a servo area and a corresponding data area, and has a surface divided into zones in the radial direction. The basic frequency varies in the servo area depending on the zones. The head is driven to read a signal from the magnetic disk. The clock generator generates a clock signal for decoding a signal read from the data area corresponding to the servo area based on a signal read from the servo area. The estimating module estimates the position of the servo area in the radial direction, from which the head reads a signal next. The controller controls the clock generator to generate a clock signal of the basic frequency before the head reaches the servo area based on the estimated position.Type: ApplicationFiled: June 22, 2010Publication date: December 30, 2010Applicant: TOSHIBA STORAGE DEVICE CORPORATIONInventors: Satoshi YAMASHITA, Kazuhiko TAKAISHI
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Patent number: 7826168Abstract: 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: GrantFiled: March 22, 2005Date of Patent: November 2, 2010Assignee: Toshiba Storage Device CorporationInventor: Kazuhiko Takaishi
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Publication number: 20100268354Abstract: In a position control device having a disturbance suppression function, loop gain is calibrated without stopping disturbance suppression control. The position control device has, for disturbance suppression control, a feedback controller for changing the loop characteristic, a table for storing a target gain according to a disturbance frequency, and a gain calibration section for calibrating open loop gain. The gain is calibrated using a target gain in the table according to the change of the loop characteristic of the feedback controller. Open loop gain can be calibrated without interrupting the disturbance suppression control, so the open loop gain can be accurately calibrated without being affected by disturbance, and accurate position control is possible.Type: ApplicationFiled: June 25, 2010Publication date: October 21, 2010Applicant: TOSHIBA STORAGE DEVICE CORPORATIONInventor: Kazuhiko Takaishi
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Patent number: 7787200Abstract: A master-disk producing device produces a master disk with master-disk identification information added. A disk producing device produces a first disk with the master-disk identification information added, using the master disk with the master-disk identification information added. A first disk device obtains, after the first disk with the master-disk identification information added is mounted, first correction information from a correction-information storing device based on the master-disk identification information of the first disk.Type: GrantFiled: May 25, 2006Date of Patent: August 31, 2010Assignee: Toshiba Storage Device CorporationInventors: Hiroyuki Suzuki, Tomoyoshi Yamada, Masanori Fukushi, Kazuhiko Takaishi, Tsugito Maruyama, Sumio Kuroda
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Publication number: 20100128385Abstract: According to one embodiment, an information storage device includes a recording/reproducing head, a positioning controller, a position detector, a storage module, and a position error detector. The position detector detects the position of the recording/reproducing head. The storage module stores servo control filters. The position error detector generates a new position error signal from a target position and the position of the recording/reproducing head when the positioning controller performs positioning control with control current obtained from a position error signal having passed through each servo control filter. Upon occurrence of a recording/reproducing error, learning to calculate a vibration amount from the position of the recording/reproducing head is sequentially performed for the servo control filters for a predetermined time.Type: ApplicationFiled: September 28, 2009Publication date: May 27, 2010Applicant: Fujitsu LimitedInventors: Takeshi Hara, Kazuhiko Takaishi
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Patent number: 7724467Abstract: A servo-mark search control unit detects in a magnetic disk a servo mark matching a servo mark selected by a servo-mark candidate selecting unit. In this case, according to an instruction from a servo-mark search control unit, a non-volatile memory managing unit writes servo-write-mode identification information corresponding to the detected servo mark in a servo-write-mode identification-information storage unit of a non-volatile memory. In this manner, a magnetic disk device can recognize by itself a servo write mode with which servo patterns were written in a magnetic disk included in the magnetic disk device.Type: GrantFiled: January 28, 2009Date of Patent: May 25, 2010Assignee: Toshiba Storage Device CorporationInventors: Satoshi Yamashita, Kazuhiko Takaishi
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Patent number: 7684142Abstract: A disk device has a positioning control system which has a disturbance suppression function in which the disturbance is suppressed quickly to prevent vibration of the head. In a positioning system having a disturbance suppression function of a disk device, an interface circuit for setting a known disturbance frequency to an initial value from the outside is installed. An unknown disturbance frequency can be immediately suppressed, or disturbance frequency control can be started from a known disturbance frequency, and even if the frequency changes thereafter, the estimated frequency can follow up to the disturbance, and the vibration of the head can be quickly prevented.Type: GrantFiled: July 13, 2006Date of Patent: March 23, 2010Assignee: Toshiba Storage Device CorporationInventor: Kazuhiko Takaishi
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Publication number: 20100049946Abstract: A processor includes: a first storage part that stores instructions of a program including sets of instruction groups, which sets are hierarchically structured; a second storage part that stores an address value of the first storage part in which an instruction to be read next is stored; a third storage part that includes storage areas respectively corresponding to hierarchical levels of the program; and a control part that executes, when an instruction read from the first storage part is a call instruction that calls a different one of the sets of instruction groups, a control to store the address value in the second storage part in one of the storage areas of the third storage part that corresponds to one of the hierarchical levels with which the different one of the sets of instruction groups being executed is associated.Type: ApplicationFiled: June 8, 2009Publication date: February 25, 2010Applicant: FUJITSU LIMITEDInventors: Nobuyuki Myouga, Kazuhiko Takaishi, Yoshinari Higashino
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Publication number: 20100014184Abstract: According to one embodiment, a position control apparatus includes: a digital control module that performs position control including disturbance adaptive control with a predetermined sampling period using a control constant, in accordance with a position error; and a table that stores the control constant corresponding to one of values sin(?T), cos(?T), and sin(?T/2), wherein the digital control module determines a control value of the actuator in accordance with the position error, calculates a value of one of estimated errors of sin(?T), cos(?T), and sin(?T/2) according to an adaptive law from a signal based on the position error, multiplies the calculated estimated error by an adaptive gain in accordance with a value of the angular frequency ?, updates one of the values, reads the corresponding control constant from the table based on the updated value, and updates the control constant.Type: ApplicationFiled: September 23, 2009Publication date: January 21, 2010Applicant: FUJITSU LIMITEDInventor: Kazuhiko Takaishi
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Publication number: 20100014185Abstract: According to one embodiment, a position control apparatus includes: a digital control module that performs position control including disturbance adaptive control with a predetermined sampling period using a control constant, in accordance with a position error between a target position and a current position of the object; and a table that stores the control constant corresponding to a value of sin(?T) or cos(?T), wherein the digital control module is configured to determine a control value of the actuator in accordance with the position error, calculates the value of sin(?T) or cos(?T) according to an adaptive law from a signal based on the position error, reads the corresponding control constant from the table in accordance with the calculated value of sin(?T) or cos(?T), and updates the control constant, to perform the position control including the disturbance adaptive control.Type: ApplicationFiled: September 24, 2009Publication date: January 21, 2010Applicant: FUJITSU LIMITEDInventor: Kazuhiko Takaishi
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Publication number: 20100014186Abstract: According to one embodiment, a position control apparatus includes: a digital control module that performs position control including disturbance adaptive control with a predetermined sampling period with the use of a control constant, in accordance with a position error between a target position and a current position of the object; and a table that stores the control constant corresponding to a value of sin(?T/2), wherein the digital control module determines a control value of the actuator in accordance with the position error, calculates the value of sin(?T/2) according to an adaptive law from a signal based on the position error, reads the corresponding control constant from the table in accordance with the calculated value of sin(?T/2), and updates the control constant.Type: ApplicationFiled: September 24, 2009Publication date: January 21, 2010Applicant: FUJITSU LIMITEDInventor: Kazuhiko Takaishi
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Publication number: 20090285073Abstract: A pattern transfer apparatus includes a storage-medium-surface detecting unit that detects a foreign substance or defect on a surface of a storage medium and specifies a position and a size of the foreign substance or defect; a relative-position adjusting unit that adjusts a relative position on a contact surface between the surface of the storage medium and a transfer pattern surface of a transfer master, and a relative-position-adjustment instructing unit that calculates an adjusted value of the relative position according to a detection result, and instructs the relative-position adjusting unit to adjust the relative position based on the adjusted value.Type: ApplicationFiled: March 5, 2009Publication date: November 19, 2009Applicant: FUJITSU LIMITEDInventors: Kazuhiko Takaishi, Masanori Fukushi
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Publication number: 20090279200Abstract: A servo-mark search control unit detects in a magnetic disk a servo mark matching a servo mark selected by a servo-mark candidate selecting unit. In this case, according to an instruction from a servo-mark search control unit, a non-volatile memory managing unit writes servo-write-mode identification information corresponding to the detected servo mark in a servo-write-mode identification-information storage unit of a non-volatile memory. In this manner, a magnetic disk device can recognize by itself a servo write mode with which servo patterns were written in a magnetic disk included in the magnetic disk device.Type: ApplicationFiled: January 28, 2009Publication date: November 12, 2009Applicant: FUJITSU LIMITEDInventors: Satoshi Yamashita, Kazuhiko Takaishi