Patents by Inventor Yoshifumi Obara
Yoshifumi Obara 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: 11551710Abstract: According to an embodiment, a magnetic disk has a plurality of second servo sectors and a plurality of third servo sectors each arranged between two second servo sectors of the plurality of second servo sectors, in which the second and third servo sectors are arranged in a circumferential direction. A controller performs a first demodulation for detecting a servo mark and demodulating a burst pattern on the servo data in each second servo sector. The controller performs a second demodulation for demodulating the burst pattern without detecting the servo mark, on the servo data in each third servo sector. The controller performs the second demodulation on the servo data in a fourth servo sector which is one of the plurality of second servo sectors in a case where the detection of the servo mark fails when the first demodulation is performed on the servo data in the fourth servo sector.Type: GrantFiled: February 23, 2022Date of Patent: January 10, 2023Assignees: Kabushiki Kaisha Toshiba, Toshiba Electronic Devices & Storage CorporationInventor: Yoshifumi Obara
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Publication number: 20220406331Abstract: According to an embodiment, a magnetic disk has a plurality of second servo sectors and a plurality of third servo sectors each arranged between two second servo sectors of the plurality of second servo sectors, in which the second and third servo sectors are arranged in a circumferential direction. A controller performs a first demodulation for detecting a servo mark and demodulating a burst pattern on the servo data in each second servo sector. The controller performs a second demodulation for demodulating the burst pattern without detecting the servo mark, on the servo data in each third servo sector. The controller performs the second demodulation on the servo data in a fourth servo sector which is one of the plurality of second servo sectors in a case where the detection of the servo mark fails when the first demodulation is performed on the servo data in the fourth servo sector.Type: ApplicationFiled: February 23, 2022Publication date: December 22, 2022Inventor: Yoshifumi Obara
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Patent number: 7719784Abstract: According to an aspect of an embodiment, an apparatus, includes: a medium having inner and outer edges and including first and second servo regions extending radially, and containing first and second servo information written thereon, respectively, the first servo region extending outwardly from the inner edge to cover tracks, the first and second servo region having positioned adjacently across a circular boundary; a head for reading out said first servo information and said second servo information; and a processor for executing a process comprising: reading out the first or second servo information; and when controlling the track position across the boundary, adjusting the relation of the first and second servo information across the boundary in control the track position.Type: GrantFiled: July 17, 2008Date of Patent: May 18, 2010Assignee: Toshiba Storage Device CorporationInventors: Takeshi Hara, Yoshifumi Obara, Shigenori Yanagi
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Patent number: 7706094Abstract: A storage device receives and holds a storage medium that is subjected to first servo writing processing for writing servo information, a Gray code of which is offset, from an inner cylinder or an outer cylinder to a predetermined cylinder and, after the first servo writing processing, subjected to second servo writing processing for writing servo information from an opposite direction to the predetermined cylinder and in which Gray codes are written to be offset not to overlap in the first or second servo writing processing and the pieces of servo information having different mark patterns are written in the first servo writing processing and the second servo writing processing. The storage device acquires cylinder information and mark patterns from the servo information written in the held storage medium and controls a position of a head based on the acquired cylinder information and mark patterns.Type: GrantFiled: May 15, 2008Date of Patent: April 27, 2010Assignee: Toshiba Storage Device CorporationInventors: Takeshi Hara, Yoshifumi Obara, Yukio Abe, Shigenori Yanagi, Mitsuo Kamimura
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Publication number: 20090059415Abstract: A storage device receives and holds a storage medium that is subjected to first servo writing processing for writing servo information, a Gray code of which is offset, from an inner cylinder or an outer cylinder to a predetermined cylinder and, after the first servo writing processing, subjected to second servo writing processing for writing servo information from an opposite direction to the predetermined cylinder and in which Gray codes are written to be offset not to overlap in the first or second servo writing processing and the pieces of servo information having different mark patterns are written in the first servo writing processing and the second servo writing processing. The storage device acquires cylinder information and mark patterns from the servo information written in the held storage medium and controls a position of a head based on the acquired cylinder information and mark patterns.Type: ApplicationFiled: May 15, 2008Publication date: March 5, 2009Applicant: FUJITSU LIMITEDInventors: Takeshi Hara, Yoshifumi Obara, Yukio Abe, Shigenori Yanagi, Mitsuo Kamimura
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Publication number: 20090059419Abstract: According to an aspect of an embodiment, an apparatus, includes: a medium having inner and outer edges and including first and second servo regions extending radially, and containing first and second servo information written thereon, respectively, the first servo region extending outwardly from the inner edge to cover tracks, the first and second servo region having positioned adjacently across a circular boundary; a head for reading out said first servo information and said second servo information; and a processor for executing a process comprising: reading out the first or second servo information; and when controlling the track position across the boundary, adjusting the relation of the first and second servo information across the boundary in control the track position.Type: ApplicationFiled: July 17, 2008Publication date: March 5, 2009Applicant: FUJITSU LIMITEDInventors: Takeshi Hara, Yoshifumi Obara, Shigenori Yanagi
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Patent number: 7486466Abstract: A storage medium (magnetic disk) in a storage device (magnetic disk device) includes a disk that stores therein data, a head that reads and writes data, a voice motor coil (VCM) that controls the head, and a ramp where the head is retracted. The storage device detects a current used for speed control during unloading of the head, and determines whether the current exceeds a predetermined value. The storage device detects a head position where the current exceeds a predetermined value as a ramp position, stores the ramp position, and unloads the head based on the ramp position.Type: GrantFiled: October 20, 2006Date of Patent: February 3, 2009Assignee: Fujitsu LimitedInventors: Takeshi Hara, Yoshifumi Obara
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Patent number: 7436612Abstract: A calculating unit calculates an interval time from a detection of a servo sync mark until a detection of an adjacent servo sync mark, for all servo sync marks on a track of a disk-shaped recording medium. A measuring unit measures, based on the calculated interval time, a deviation amount between a link interval time that represents the interval time between a servo sync mark recorded first and a servo sync mark recorded last and an ideal interval time that represents the link interval time when it is assumed that all the servo sync marks on the track are written at equal intervals.Type: GrantFiled: December 22, 2005Date of Patent: October 14, 2008Assignee: Fujitsu LimitedInventors: Yoshifumi Obara, Takao Abe, Takeshi Hara
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Publication number: 20080043357Abstract: Before a system area of the storage device is read immediately after the activation of the storage device, a read signal is output from a magnetic head to read servo information in the system area. An HDIC amplifies gain of the read signal as first gain amplification. Then, a VGA in a read channel amplifies gain of the read signal after the first gain amplification as second gain amplification. The read signal for the servo information is amplified by two stages of amplifiers to a level sufficient to demodulate the servo information.Type: ApplicationFiled: December 28, 2006Publication date: February 21, 2008Inventors: Yoshifumi Obara, Takeshi Hara
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Publication number: 20070291394Abstract: A storage medium (magnetic disk) in a storage device (magnetic disk device) includes a disk that stores therein data, a head that reads and writes data, a voice motor coil (VCM) that controls the head, and a ramp where the head is retracted. The storage device detects a current used for speed control during unloading of the head, and determines whether the current exceeds a predetermined value. The storage device detects a head position where the current exceeds a predetermined value as a ramp position, stores the ramp position, and unloads the head based on the ramp position.Type: ApplicationFiled: October 20, 2006Publication date: December 20, 2007Inventors: Takeshi Hara, Yoshifumi Obara
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Patent number: 7277253Abstract: A storage device configured to load and unload a head against a storage medium, includes a latch mechanism configured to latch the unloaded head, a head moving mechanism configured to move the head, a measuring part configured to measure an unlatch force necessary for unlatching the head latched by the latch mechanism, by applying a constant electrical current to the head mechanism so that the head is moved in a load direction, by measuring a back electromotive voltage, and calculating a moving speed and acceleration of the head, a storing part configured to store information indicating the measured unlatch force in the storage device, and a control part configured to apply a driving electrical current corresponding to the stored information to the head moving mechanism where the head is latched by the latch mechanism at the time of loading.Type: GrantFiled: February 21, 2006Date of Patent: October 2, 2007Assignee: Fujitsu LimitedInventors: Satoshi Yamashita, Takeshi Hara, Yoshifumi Obara
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Patent number: 7212371Abstract: A storage device, which comprises a storage media, a spindle motor which spins the storage media, a head unit which records and reads the data to the storage media, an actuator which carries out the positioning operation to the head unit on the storage media, a loading and unloading system which controls the actuator and carries out the unload operation that withdraws the head unit from the storage media and the loading operation that shifts the head unit onto the storage media, and a measurement means which measures the unloading energy required for the unload operation.Type: GrantFiled: February 7, 2005Date of Patent: May 1, 2007Assignee: Fujitsu LimitedInventors: Yukio Abe, Shunji Saitou, Yoshifumi Obara
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Publication number: 20070064329Abstract: A calculating unit calculates an interval time from a detection of a servo sync mark until a detection of an adjacent servo sync mark, for all servo sync marks on a track of a disk-shaped recording medium. A measuring unit measures, based on the calculated interval time, a deviation amount between a link interval time that represents the interval time between a servo sync mark recorded first and a servo sync mark recorded last and an ideal interval time that represents the link interval time when it is assumed that all the servo sync marks on the track are written at equal intervals.Type: ApplicationFiled: December 22, 2005Publication date: March 22, 2007Inventors: Yoshifumi Obara, Takao Abe, Takeshi Hara
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Publication number: 20070064331Abstract: A storage device configured to load and unload a head against a storage medium, includes a latch mechanism configured to latch the unloaded head, a head moving mechanism configured to move the head, a measuring part configured to measure an unlatch force necessary for unlatching the head latched by the latch mechanism, by applying a constant electrical current to the head mechanism so that the head is moved in a load direction, by measuring a back electromotive voltage, and calculating a moving speed and acceleration of the head, a storing part configured to store information indicating the measured unlatch force in the storage device, and a control part configured to apply a driving electrical current corresponding to the stored information to the head moving mechanism where the head is latched by the latch mechanism at the time of loading.Type: ApplicationFiled: February 21, 2006Publication date: March 22, 2007Inventors: Satoshi Yamashita, Takeshi Hara, Yoshifumi Obara
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Publication number: 20060082919Abstract: A storage device, which comprises a storage media, a spindle motor which spins the storage media, a head unit which records and reads the data to the storage media, an actuator which carries out the positioning operation to the head unit on the storage media, a loading and unloading system which controls the actuator and carries out the unload operation that withdraws the head unit from the storage media and the loading operation that shifts the head unit onto the storage media, and a measurement means which measures the unloading energy required for the unload operation.Type: ApplicationFiled: February 7, 2005Publication date: April 20, 2006Inventors: Yukio Abe, Shunji Saitou, Yoshifumi Obara