Patents by Inventor Yoshiyuki Kagami
Yoshiyuki Kagami 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: 7508610Abstract: A servo-frame recording apparatus includes: a sector information rearranging section for rearranging serial bits of the sector information that is binary data; a first ExOR section for performing the ExOR (exclusive OR) on the sector information, the serial bits of which have been rearranged by said sector information rearranging section, and the track information, so that an exclusive logical sum is obtained; and a writing section for wiring the exclusive logical sum obtained by said ExOR section into the servo frame. With this configuration, a data length required for recording gray information and sector information can be shortened without lowering the reliability of a magnetic disk.Type: GrantFiled: June 14, 2005Date of Patent: March 24, 2009Assignee: Fujitsu LimitedInventors: Tatsuhiko Kosugi, Yoshiyuki Kagami
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Publication number: 20090002860Abstract: A storage apparatus capable of measuring the vibration of a head vibration having a high frequency includes: a gate generation section that generates a plurality of first gate signals indicating the timing at which the head reads out servo information having a waveform for measurement of a reproduction signal level from a storage medium on which the servo information is written at predetermined intervals and on a first track of which a first waveform serving as a waveform for measurement of a reproduction signal level is written and which is at least a predetermined track and a second gate signal indicating at least one timing between the first gate signals; and a measurement section that measures the reproduction signal level of the waveform for measurement reproduced by the head at the timing of the gate signals.Type: ApplicationFiled: March 20, 2008Publication date: January 1, 2009Applicant: FUJITSU LIMITEDInventors: Kohei Takamatsu, Yoshiyuki Kagami
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Publication number: 20080159092Abstract: A first and second phase patterns of which phases are the same and a third and fourth phase patterns of which phases are opposite of the first and second phase patterns and of which phases are different from each other, are formed on a recording medium. A position information in a first track range is demodulated based on a first phase difference of the regeneration signals of the first and second phase pattern and of the third phase pattern, position information in a second track range is demodulated based on a second phase difference of the regeneration signals in the third phase pattern and the fourth phase pattern, and position information in a third track range is demodulated based on the first phase difference according to an angle difference between the first phase difference and a phase of the regeneration signal in the third phase pattern.Type: ApplicationFiled: December 19, 2007Publication date: July 3, 2008Applicant: Fujitsu LimitedInventors: Yoshiyuki Kagami, Tatsuhiko Kosugi
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Patent number: 7365927Abstract: An eccentricity correction data recording method, a disk-shaped recording medium, a head position control method and an information recording and reproducing apparatus are disclosed for effective eccentricity correction on cylinders of a disk-shaped recording medium. The eccentricity correction data recording method is for position control over a recording and reproducing head on a disk-shaped recording medium having at least one user data recording area to record user data, the method including the step of recording the eccentricity correction data in a user data recording area.Type: GrantFiled: February 23, 2004Date of Patent: April 29, 2008Assignee: Fujitsu LimitedInventors: Kohei Takamatsu, Yoshiyuki Kagami, Shuichi Hashimoto
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Patent number: 7196865Abstract: A recording apparatus capable of securely reading out data for causing a head to follow along circular tracks set virtually. Therefore, on-track control along the virtual tracks is possible by the conversion data on the discoid record medium even when, for example, the printed circuit board in a recording apparatus has been replaced.Type: GrantFiled: October 22, 2003Date of Patent: March 27, 2007Assignee: Fujitsu LimitedInventors: Kazunori Mori, Isamu Tomita, Tatsuhiko Kosugi, Yoshiyuki Kagami
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Patent number: 7164261Abstract: A resonance-frequency measuring method is used for measuring a resonance frequency of an information recording/reproducing device reproducing information recorded on a medium by driving a mechanism unit. The resonance-frequency measuring method includes the measuring step of applying sine-wave oscillations at different frequencies one by one to the mechanism unit, and counting the number of times information reproduced upon application of each of the sine-wave oscillations differs from information indicating an aimed location, and the resonance-frequency determining step of determining the resonance frequency according to the number of times counted in the measuring step.Type: GrantFiled: April 15, 2004Date of Patent: January 16, 2007Assignee: Fujitsu LimitedInventors: Shuichi Hashimoto, Ryuki Kubohara, Tatsuhiko Kosugi, Takeyori Hara, Yoshiyuki Kagami
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Patent number: 7136245Abstract: A disk device performs position control of a head. An acquiring unit acquires correction information and check information from a disk for checking the correction information. A judging unit judges whether the correction information acquired should be used for correcting position information recorded in the disk, based on the correction information acquired and the check information acquired.Type: GrantFiled: July 23, 2004Date of Patent: November 14, 2006Assignee: Fujitsu LimitedInventors: Kazunori Mori, Isamu Tomita, Takeyori Hara, Yoshiyuki Kagami, Kouhei Takamatsu
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Publication number: 20060221479Abstract: A servo-frame recording apparatus includes: a sector information rearranging section for rearranging serial bits of the sector information that is binary data; a first ExOR section for performing the ExOR (exclusive OR) on the sector information, the serial bits of which have been rearranged by said sector information rearranging section, and the track information, so that an exclusive logical sum is obtained; and a writing section for wiring the exclusive logical sum obtained by said ExOR section into the servo frame. With this configuration, a data length required for recording gray information and sector information can be shortened without lowering the reliability of a magnetic disk.Type: ApplicationFiled: June 14, 2005Publication date: October 5, 2006Inventors: Tatsuhiko Kosugi, Yoshiyuki Kagami
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Patent number: 7050250Abstract: There are provided a storage apparatus and a computer-readable recording medium, on whose storage areas, servo frames are arranged at uniform intervals in a spoke-like pattern. Each of the servo frames has an index bit storing section storing, as an index bit, part of an index pattern, which is operable to identify a storage area. The apparatus and the recording medium have a storage area recognizing unit for recognizing the storage areas based on the index bits, which are obtained by an index bit obtaining unit. The index bits, stored one in each of the index bit storing sections of the servo frames, are adapted to form, when being sequentially arranged, an index bit string in which such an index pattern repeatedly appears.Type: GrantFiled: February 25, 2004Date of Patent: May 23, 2006Assignee: Fujitsu LimitedInventors: Tatsuhiko Kosugi, Isamu Tomita, Kazunori Mori, Yoshiyuki Kagami, Ryuki Kubohara
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Patent number: 7002769Abstract: There is provided a head control method controlling move of a head on a discoidal recording medium including the steps of: partitioning the discoidal recording medium which has position information recorded thereon at radially equal spacing into a plurality of zones; and demodulating the position information using a coefficient set for each of the zones.Type: GrantFiled: August 18, 2004Date of Patent: February 21, 2006Assignee: Fujitsu LimitedInventors: Yoshiyuki Kagami, Isamu Tomita, Shuichi Hashimoto
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Publication number: 20050190480Abstract: A disk device performs position control of a head. An acquiring unit acquires correction information and check information from a disk for checking the correction information. A judging unit judges whether the correction information acquired should be used for correcting position information recorded in the disk, based on the correction information acquired and the check information acquired.Type: ApplicationFiled: July 23, 2004Publication date: September 1, 2005Inventors: Kazunori Mori, Isamu Tomita, Takeyori Hara, Yoshiyuki Kagami, Kouhei Takamatsu
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Publication number: 20050088775Abstract: A recording apparatus capable of securely reading out data for causing a head to follow along circular tracks set virtually. Therefore, on-track control along the virtual tracks is possible by the conversion data on the discoid record medium even when, for example, the printed circuit board in a recording apparatus has been replaced.Type: ApplicationFiled: October 22, 2003Publication date: April 28, 2005Inventors: Kazunori Mori, Isamu Tomita, Tatsuhiko Kosugi, Yoshiyuki Kagami
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Publication number: 20050057837Abstract: An eccentricity correction data recording method, a disk-shaped recording medium, a head position control method and an information recording and reproducing apparatus are disclosed for effective eccentricity correction on cylinders of a disk-shaped recording medium. The eccentricity correction data recording method is for position control over a recording and reproducing head on a disk-shaped recording medium having at least one user data recording area to record user data, the method including the step of recording the eccentricity correction data in a user data recording area.Type: ApplicationFiled: February 23, 2004Publication date: March 17, 2005Inventors: Kohei Takamatsu, Yoshiyuki Kagami, Shuichi Hashimoto
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Publication number: 20050041322Abstract: There is provided a head control method controlling move of a head on a discoidal recording medium including the steps of: partitioning the discoidal recording medium which has position information recorded thereon at radially equal spacing into a plurality of zones; and demodulating the position information using a coefficient set for each of the zones.Type: ApplicationFiled: August 18, 2004Publication date: February 24, 2005Inventors: Yoshiyuki Kagami, Isamu Tomita, Shuichi Hashimoto
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Publication number: 20040223247Abstract: There are provided a storage apparatus and a computer-readable recording medium, on whose storage areas, servo frames are arranged at uniform intervals in a spoke-like pattern. Each of the servo frames has an index bit storing section storing, as an index bit, part of an index pattern, which is operable to identify a storage area. The apparatus and the recording medium have a storage area recognizing unit for recognizing the storage areas based on the index bits, which are obtained by an index bit obtaining unit. The index bits, stored one in each of the index bit storing sections of the servo frames, are adapted to form, when being sequentially arranged, an index bit string in which such an index pattern repeatedly appears.Type: ApplicationFiled: February 25, 2004Publication date: November 11, 2004Applicant: FUJITSU LIMITEDInventors: Tatsuhiko Kosugi, Isamu Tomita, Kazunori Mori, Yoshiyuki Kagami, Ryuki Kubohara
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Publication number: 20040196053Abstract: A resonance-frequency measuring method is used for measuring a resonance frequency of an information recording/reproducing device reproducing information recorded on a medium by driving a mechanism unit. The resonance-frequency measuring method comprises the measuring step of applying sine-wave oscillations at different frequencies one by one to the mechanism unit, and counting the number of times information reproduced upon application of each of the sine-wave oscillations differs from information indicating an aimed location, and the resonance-frequency determining step of determining the resonance frequency according to the number of times counted in the measuring step.Type: ApplicationFiled: April 15, 2004Publication date: October 7, 2004Applicant: Fujitsu LimitedInventors: Shuichi Hashimoto, Ryuki Kubohara, Tatsuhiko Kosugi, Takeyori Hara, Yoshiyuki Kagami
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Patent number: 6774615Abstract: A resonance-frequency measuring method is used for measuring a resonance frequency of an information recording/reproducing device reproducing information recorded on a medium by driving a mechanism unit. The resonance-frequency measuring method comprises the measuring step of applying sine-wave oscillations at different frequencies one by one to the mechanism unit, and counting the number of times information reproduced upon application of each of the sine-wave oscillations differs from information indicating an aimed location, and the resonance-frequency determining step of determining the resonance frequency according to the number of times counted in the measuring step.Type: GrantFiled: January 25, 2002Date of Patent: August 10, 2004Assignee: Fujitsu LimitedInventors: Susumu Yoshida, Shuichi Hashimoto, Ryuki Kubohara, Tatsuhiko Kosugi, Takeyori Hara, Yoshiyuki Kagami
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Publication number: 20030057935Abstract: A resonance-frequency measuring method is used for measuring a resonance frequency of an information recording/reproducing device reproducing information recorded on a medium by driving a mechanism unit. The resonance-frequency measuring method comprises the measuring step of applying sine-wave oscillations at different frequencies one by one to the mechanism unit, and counting the number of times information reproduced upon application of each of the sine-wave oscillations differs from information indicating an aimed location, and the resonance-frequency determining step of determining the resonance frequency according to the number of times counted in the measuring step.Type: ApplicationFiled: January 25, 2002Publication date: March 27, 2003Applicant: FUJITSU LIMITEDInventors: Susumu Yoshida, Shuichi Hashimoto, Ryuki Kubohara, Tatsuhiko Kosugi, Takeyori Hara, Yoshiyuki Kagami
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Patent number: 6535348Abstract: A servo control method and an information storage device are provided. In the method and device, positional information is detected in accordance with servo information including a plurality of positional regions having phase differences between tracks. The positional regions consist of a first positional region in which the phase difference between tracks is +90°, a second positional region in which the phase difference between tracks is −90°, a third positional region in which the phase difference between tracks is +90°, and a fourth positional region in which the phase difference between tracks is −135°. A deviation from a reference track is detected from the phase difference between the vector of a reproduction signal of the second positional region and the vector of a reproduction signal of the fourth positional region. Thus, a wide range of deviation can be detected.Type: GrantFiled: October 6, 1999Date of Patent: March 18, 2003Assignee: Fujitsu LimitedInventors: Yoshiyuki Kagami, Tatsuhiko Kosugi