Patents by Inventor Yoshihisa Kamo
Yoshihisa Kamo 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: 7486485Abstract: Embodiments of the invention prevent a decrease in magnetization or demagnetization from occurring to recording magnetization regardless of a direction in which a stray field is applied. In one embodiment, an apparatus for data storage system comprises a head having a magnetic field shield in the vicinity of a main pole, and a cover of the device, using a constituent material with a magnetic field shielding effect, across the cover, or at part thereof. When a stray field in a direction perpendicular to a recording medium is applied, the effect of the magnetic field is alleviated by the magnetic field shield installed in the vicinity of the main pole. In such a case, it need only be sufficient to form the magnetic field shield in a shape optimum for removing the stray field in the perpendicular direction only.Type: GrantFiled: October 28, 2005Date of Patent: February 3, 2009Assignee: Hitachi Global Storage Technologies Netherlands B.V.Inventors: Takehiko Hamaguchi, Yoshihisa Kamo, Hideaki Maeda, Yukiya Shimizu, Ikuya Tagawa, Tetsuo Yuki
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Patent number: 7434095Abstract: A data storage system connectable to a host unit which issues data read/write requests to the data storage system, and which includes a plurality of disc units, and a controller connected to the disc units. A fault can occur in any of the disc units. The disc units store data in a plurality of data groups and error correcting data corresponding to each of the data groups. The controller, operable in different modes, performs processing of reconstructing data stored in any of the disc units in which a fault has occurred based on all other data belonging to any of the data groups to which the data to be reconstructed belongs and error correcting data corresponding to any of the data groups to which the data to be reconstructed belongs, and performs processing of data read/write requests from the host unit.Type: GrantFiled: September 6, 2005Date of Patent: October 7, 2008Assignee: Hitachi, Ltd.Inventors: Atsushi Tanaka, Yoshihisa Kamo, Hitoshi Kakuta
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Patent number: 7320089Abstract: When receiving a write request from a processor, a control unit checks the condition of existence (or the presence/absence) in a cache for information necessary for generation of an updated value of a parity record, receives write data and reports the completion of the write request to the processor. In asynchronism with the write request from the processor, the control unit performs a load process for that information among the information necessary for generation of the updated value of the parity record which may be prepared in asynchronism with the write request from the processor and a write after process for the updated value of the parity record.Type: GrantFiled: September 22, 2004Date of Patent: January 15, 2008Assignee: Hitachi, Ltd.Inventors: Akira Yamamoto, Hiroyuki Kitajima, Kouji Arai, Yoshihisa Kamo
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Patent number: 7242656Abstract: With respect to the disk drives provided power from a single power source in a disk drive system, start up power is first supplied to a first start-up group of the disks, preferably comprising all of the master disks, with the size of the group being selected so that the required current does not exceed the capacity of the power source. When the disk drives of the first group have substantially reached steady state, start-up is conducted with respect to a second start-up group of the disk drives so that the current required during start-up for the second group and the current required for steady state drive of the first start-up group does not exceed the capacity of the power source. With respect to each start-up group, the number of disk drives is the maximum integer value and decreases or remains the same with respect to subsequent start-up groups.Type: GrantFiled: July 14, 2003Date of Patent: July 10, 2007Assignee: Hitachi, Ltd.Inventors: Yoshihisa Kamo, Hitoshi Kakuta, Atsushi Tanaka, Yosuke Seo
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Publication number: 20060092556Abstract: Embodiments of the invention prevent a decrease in magnetization or demagnetization from occurring to recording magnetization regardless of a direction in which a stray field is applied. In one embodiment, an apparatus for data storage system comprises a head having a magnetic field shield in the vicinity of a main pole, and a cover of the device, using a constituent material with a magnetic field shielding effect, across the cover, or at part thereof. When a stray field in a direction perpendicular to a recording medium is applied, the effect of the magnetic field is alleviated by the magnetic field shield installed in the vicinity of the main pole. In such a case, it need only be sufficient to form the magnetic field shield in a shape optimum for removing the stray field in the perpendicular direction only.Type: ApplicationFiled: October 28, 2005Publication date: May 4, 2006Applicant: Hitachi Global Storage Technologies Netherlands B.V.Inventors: Takehiko Hamaguchi, Yoshihisa Kamo, Hideaki Maeda, Yukiya Shimizu, Ikuya Tagawa, Tetsuo Yuki
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Publication number: 20060010343Abstract: A data storage system connectable to a host unit which issues data read/write requests to the data storage system, and which includes a plurality of disc units, and a controller connected to the disc units. A fault can occur in any of the disc units. The disc units store data in a plurality of data groups and error correcting data corresponding to each of the data groups. The controller, operable in different modes, performs processing of reconstructing data stored in any of the disc units in which a fault has occurred based on all other data belonging to any of the data groups to which the data to be reconstructed belongs and error correcting data corresponding to any of the data groups to which the data to be reconstructed belongs, and performs processing of data read/write requests from the host unit.Type: ApplicationFiled: September 6, 2005Publication date: January 12, 2006Inventors: Atsushi Tanaka, Yoshihisa Kamo, Hitoshi Kakuta
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Patent number: 6966011Abstract: A data storage system connectable to a host unit which issues data read/write requests to the data storage system, and which includes a plurality of disc units, and a controller connected to the disc units. A fault can occur in any of the disc units. The disc units store data in a plurality of data groups and error correcting data corresponding to each of the data groups. The controller, operable in different modes, performs processing of reconstructing data stored in any of the disc units in which a fault has occurred based on all other data belonging to any of the data groups to which the data to be reconstructed belongs and error correcting data corresponding to any of the data groups to which the data to be reconstructed belongs, and performs processing of data read/write requests from the host unit.Type: GrantFiled: July 2, 2003Date of Patent: November 15, 2005Assignee: Hitachi, Ltd.Inventors: Atsushi Tanaka, Yoshihisa Kamo, Hitoshi Kakuta
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Patent number: 6874101Abstract: When receiving a write request from a processor, a control unit checks the condition of existence (or the presence/absence) in a cache for information necessary for generation of an updated value of a parity record, receives write data and reports the completion of the write request to the processor. In asynchronism with the write request from the processor, the control unit performs a load process for that information among the information necessary for generation of the updated value of the parity record which may be prepared in asynchronism with the write request from the processor and a write after process for the updated value of the parity record.Type: GrantFiled: February 20, 2003Date of Patent: March 29, 2005Assignee: Hitachi, Ltd.Inventors: Akira Yamamoto, Hiroyuki Kitajima, Kouji Arai, Yoshihisa Kamo
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Publication number: 20050050267Abstract: When receiving a write request from a processor, a control unit checks the condition of existence (or the presence/absence) in a cache for information necessary for generation of an updated value of a parity record, receives write data and reports the completion of the write request to the processor. In asynchronism with the write request from the processor, the control unit performs a load process for that information among the information necessary for generation of the updated value of the parity record which may be prepared in asynchronism with the write request from the processor and a write after process for the updated value of the parity record.Type: ApplicationFiled: September 22, 2004Publication date: March 3, 2005Inventors: Akira Yamamoto, Hiroyuki Kitajima, Kouji Arai, Yoshihisa Kamo
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Publication number: 20040153730Abstract: A data storage system connectable to a host unit which issues data read/write requests to the data storage system, and which includes a plurality of disc units, and a controller connected to the disc units. A fault can occur in any of the disc units. The disc units store data in a plurality of data groups and error correcting data corresponding to each of the data groups. The controller, operable in different modes, performs processing of reconstructing data stored in any of the disc units in which a fault has occurred based on all other data belonging to any of the data groups to which the data to be reconstructed belongs and error correcting data corresponding to any of the data groups to which the data to be reconstructed belongs, and performs processing of data read/write requests from the host unit.Type: ApplicationFiled: July 2, 2003Publication date: August 5, 2004Inventors: Atsushi Tanaka, Yoshihisa Kamo, Hitoshi Kakuta
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Patent number: 6757839Abstract: When receiving a write request from a processor, a control unit checks the condition of existence (or the presence/absence) in a cache for information necessary for generation of an updated value of a parity record, receives write data and reports the completion of the write request to the processor. In asynchronism with the write request from the processor, the control unit performs a load process for that information among the information necessary for generation of the updated value of the parity record which may be prepared in asynchronism with the write request from the processor and a write after process for the updated value of the parity record.Type: GrantFiled: December 16, 2002Date of Patent: June 29, 2004Assignee: Hitachi, Ltd.Inventors: Akira Yamamoto, Hiroyuki Kitajima, Kouji Arai, Yoshihisa Kamo
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Publication number: 20040107313Abstract: With respect to the disk drives provided power from a single power source in a disk drive system, start up power is first supplied to a first start-up group of the disks, preferably comprising all of the master disks, with the size of the group being selected so that the required current does not exceed the capacity of the power source. When the disk drives of the first group have substantially reached steady state, start-up is conducted with respect to a second start-up group of the disk drives so that the current required during start-up for the second group and the current required for steady state drive of the first start-up group does not exceed the capacity of the power source. With respect to each start-up group, the number of disk drives is the maximum integer value and decreases or remains the same with respect to subsequent start-up groups.Type: ApplicationFiled: July 14, 2003Publication date: June 3, 2004Applicant: Hitachi, Ltd.Inventors: Yoshihisa Kamo, Hitoshi Kakuta, Atsushi Tanaka, Yosuke Seo
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Publication number: 20040078645Abstract: When receiving a write request from a processor, a control unit checks the condition of existence (or the presence/absence) in a cache for information necessary for generation of an updated value of a parity record, receives write data and reports the completion of the write request to the processor. In asynchronism with the write request from the processor, the control unit performs a load process for that information among the information necessary for generation of the updated value of the parity record which may be prepared in asynchronism with the write request from the processor and a write after process for the updated value of the parity record.Type: ApplicationFiled: December 16, 2002Publication date: April 22, 2004Applicant: Hitachi, Ltd.Inventors: Akira Yamamoto, Hiroyuki Kitajima, Kouji Arai, Yoshihisa Kamo
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Patent number: 6625748Abstract: A data storage system connectable to a host unit which issues data read/write requests to the data storage system, and which includes a plurality of disc units, and a controller connected to the disc units. A fault can occur in any of the disc units. The disc units store data in a plurality of data groups and error correcting data corresponding to each of the data groups. The controller performs processing of reconstructing data stored in any of the disc units in which a fault has occurred based on all other data belonging to any of the data groups to which the data to be reconstructed belongs and error correcting data corresponding to any of the data groups to which the data to be reconstructed belongs, and performs processing of data read/write requests from the host unit.Type: GrantFiled: November 15, 2000Date of Patent: September 23, 2003Assignee: Hitachi, Ltd.Inventors: Atsushi Tanaka, Yoshihisa Kamo, Hitoshi Kakuta
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Patent number: 6625690Abstract: With respect to the disk drives provided power from a single power source in a disk drive system, start up power is first supplied to a first start-up group of the disks, preferably comprising all of the master disks, with the size of the group being selected so that the required current does not exceed the capacity of the power source. When the disk drives of the first group have substantially reached steady state, start-up is conducted with respect to a second start-up group of the disk drives so that the current required during start-up for the second group and the current required for steady state drive of the first start-up group does not exceed the capacity of the power source. With respect to each start-up group, the number of disk drives is the maximum integer value and decreases or remains the same with respect to subsequent start-up groups.Type: GrantFiled: April 16, 2002Date of Patent: September 23, 2003Assignee: Hitachi, Ltd.Inventors: Yoshihisa Kamo, Hitoshi Kakuta, Atsushi Tanaka, Yosuke Seo
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Patent number: 6611897Abstract: In a disk array subsystem capable of changing the data redundancy method between a duplicating method and a parity method, the load of data transfer occurring at the time of changing the data redundant method is reduced. In the disk array subsystem, since one data of the duplicated data are used for data for the parity data area, the one data secures an area for storing parity prepared from the data. With the arrangement, it is not necessary to transfer the data when the data redundancy method is changed from the duplicating to the parity method and the data transfer load is mitigated.Type: GrantFiled: April 17, 2002Date of Patent: August 26, 2003Assignee: Hitachi, Ltd.Inventors: Tsunetaka Komachiya, Yoshihisa Kamo, Akira Yamamoto
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Publication number: 20030126495Abstract: When receiving a write request from a processor, a control unit checks the condition of existence (or the presence/absence) in a cache for information necessary for generation of an updated value of a parity record, receives write data and reports the completion of the write request to the processor. In asynchronism with the write request from the processor, the control unit performs a load process for that information among the information necessary for generation of the updated value of the parity record which may be prepared in asynchronism with the write request from the processor and a write after process for the updated value of the parity record.Type: ApplicationFiled: February 20, 2003Publication date: July 3, 2003Applicant: Hitachi, Ltd.Inventors: Akira Yamamoto, Hiroyuki Kitajima, Kouji Arai, Yoshihisa Kamo
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Patent number: 6571314Abstract: In a disk array subsystem capable of changing the data redundancy method between a duplicating method and a parity method, the load of data transfer occurring at the time of changing the data redundant method is reduced. In the disk array subsystem, since one data of the duplicated data are used for data for the parity data area, the one data secures an area for storing parity prepared from the data. With the arrangement, it is not necessary to transfer the data when the data redundancy method is changed from the duplicating to the parity method and the data transfer load is mitigated.Type: GrantFiled: March 22, 1999Date of Patent: May 27, 2003Assignee: Hitachi, Ltd.Inventors: Tsunetaka Komachiya, Yoshihisa Kamo, Akira Yamamoto
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Patent number: 6532549Abstract: When receiving a write request from a processor, a control unit checks the condition of existence (or the presence/absence) in a cache for information necessary for generation of an updated value of a parity record, receives write data and reports the completion of the write request to the processor. In asynchronism with the write request from the processor, the control unit performs a load process for that information among the information necessary for generation of the updated value of the parity record which may be prepared in asynchronism with the write request from the processor and a write after process for the updated value of the parity record.Type: GrantFiled: September 21, 2001Date of Patent: March 11, 2003Assignee: Hitachi, Ltd.Inventors: Akira Yamamoto, Hiroyuki Kitajima, Kouji Arai, Yoshihisa Kamo
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Publication number: 20020116574Abstract: With respect to the disk drives provided power from a single power source in a disk drive system, start up power is first supplied to a first start-up group of the disks, preferably comprising all of the master disks, with the size of the group being selected so that the required current does not exceed the capacity of the power source. When the disk drives of the first group have substantially reached steady state, start-up is conducted with respect to a second start-up group of the disk drives so that the current required during start-up for the second group and the current required for steady state drive of the first start-up group does not exceed the capacitv of the power source. With respect to each start-up group, the number of disk drives is the maximum integer value and decreases or remains the same with respect to subsequent start-up groups.Type: ApplicationFiled: April 16, 2002Publication date: August 22, 2002Applicant: Hitachi, Ltd.Inventors: Yoshihisa Kamo, Hitoshi Kakuta, Atsushi Tanaka, Yosuke Seo