Patents by Inventor Nobuhiro Maeto
Nobuhiro Maeto 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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Publication number: 20250157488Abstract: According to one embodiment, a magnetic disk device including a disk, a head which writes data to the disk and reads data from the disk, and a controller which sets a first DOL for a first sector group and a second DOL for a second sector group to different values, the first sector group including one or more first sectors and a first parity sector, the first sectors which allow an error correction process to be performed for each track based on the first parity sector, and are continuously arranged in a circumferential direction of the disk from the first parity sector, the second sector group including one or more second sectors which allow no error correction process to be performed for each track, and are continuously arranged in the circumferential direction.Type: ApplicationFiled: January 16, 2025Publication date: May 15, 2025Applicants: KABUSHIKI KAISHA TOSHIBA, TOSHIBA ELECTRONIC DEVICES & STORAGE CORPORATIONInventor: Nobuhiro MAETO
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Publication number: 20250095684Abstract: According to an embodiment, tracks on a magnetic disk each include a long-distance sector having a length in the circumferential direction covering two or more servo sectors. A controller executes an acquisition operation to acquire one or more evaluation amounts on the basis of a track pitch in each of the two or more servo sectors included in a portion adjacent to the long-distance sector. The controller executes a protection operation to protect data of an adjacent track in a case where a total value of the one or more evaluation amounts exceeds a first threshold value.Type: ApplicationFiled: November 7, 2024Publication date: March 20, 2025Inventor: Nobuhiro MAETO
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Patent number: 12236977Abstract: According to one embodiment, a magnetic disk device including a disk, a head which writes data to the disk and reads data from the disk, and a controller which sets a first DOL for a first sector group and a second DOL for a second sector group to different values, the first sector group including one or more first sectors and a first parity sector, the first sectors which allow an error correction process to be performed for each track based on the first parity sector, and are continuously arranged in a circumferential direction of the disk from the first parity sector, the second sector group including one or more second sectors which allow no error correction process to be performed for each track, and are continuously arranged in the circumferential direction.Type: GrantFiled: October 10, 2023Date of Patent: February 25, 2025Assignees: Kabushiki Kaisha Toshiba, Toshiba Electronic Devices & Storage CorporationInventor: Nobuhiro Maeto
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Patent number: 12230297Abstract: According to one embodiment, a magnetic disk device includes a disk, a head configured to write data to the disk and read the data from the disk, and a controller configured to control write processing based on a first determination value corresponding to a first shift amount defined for the excessive number of times at which the first shift amount of the head in a radial direction of the disk exceeds a first threshold value causing a read error in a second track adjacent to a first track in the radial direction at a time of the write processing of the first track of the disk, and a second threshold value changing the write processing.Type: GrantFiled: August 29, 2022Date of Patent: February 18, 2025Assignees: Kabushiki Kaisha Toshiba, Toshiba Electronic Devices & Storage CorporationInventor: Nobuhiro Maeto
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Patent number: 12223986Abstract: According to one embodiment, a magnetic disk device includes a disk, a write head, and a write processing unit. The write processing unit executes first write processing of writing data to a first segment of a first data sector in a first data track. The write processing unit then executes second write processing of writing data to a first segment of a second data sector in the first data track. The write processing unit then executes third write processing of writing data to a second segment of the first data sector in a second data track.Type: GrantFiled: November 30, 2023Date of Patent: February 11, 2025Assignees: Kabushiki Kaisha Toshiba, Toshiba Electronic Devices & Storage CorporationInventor: Nobuhiro Maeto
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Patent number: 12176002Abstract: According to an embodiment, tracks on a magnetic disk each include a long-distance sector having a length in the circumferential direction covering two or more servo sectors. A controller executes an acquisition operation to acquire one or more evaluation amounts on the basis of a track pitch in each of the two or more servo sectors included in a portion adjacent to the long-distance sector. The controller executes a protection operation to protect data of an adjacent track in a case where a total value of the one or more evaluation amounts exceeds a first threshold value.Type: GrantFiled: December 20, 2023Date of Patent: December 24, 2024Assignees: Kabushiki Kaisha Toshiba, Toshiba Electronic Devices & Storage CorporationInventor: Nobuhiro Maeto
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Publication number: 20240312481Abstract: According to one embodiment, a magnetic disk device includes a disk, a head configured to write data to the disk and read the data from the disk, and a controller configured to control write processing based on a first determination value corresponding to a first shift amount defined for the excessive number of times at which the first shift amount of the head in a radial direction of the disk exceeds a first threshold value causing a read error in a second track adjacent to a first track in the radial direction at a time of the write processing of the first track of the disk, and a second threshold value changing the write processing.Type: ApplicationFiled: May 28, 2024Publication date: September 19, 2024Applicants: KABUSHIKI KAISHA TOSHIBA, Toshiba Electronic Devices & Storage CorporationInventor: Nobuhiro MAETO
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Publication number: 20240087603Abstract: According to one embodiment, a magnetic disk device includes a disk that has a track including a first servo sector and a second servo sector that is different from the first servo sector, a head that writes data to the disk and reads data from the disk, and a controller that records first signal strength record data related to a signal strength at which first target servo data that is a target of the first servo sector is read, and standardizes first signal strength data related to a signal strength at which the first target servo data is read when the first target servo data is read.Type: ApplicationFiled: November 21, 2023Publication date: March 14, 2024Inventor: Nobuhiro MAETO
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Publication number: 20240038267Abstract: According to one embodiment, a magnetic disk device including a disk, a head which writes data to the disk and reads data from the disk, and a controller which sets a first DOL for a first sector group and a second DOL for a second sector group to different values, the first sector group including one or more first sectors and a first parity sector, the first sectors which allow an error correction process to be performed for each track based on the first parity sector, and are continuously arranged in a circumferential direction of the disk from the first parity sector, the second sector group including one or more second sectors which allow no error correction process to be performed for each track, and are continuously arranged in the circumferential direction.Type: ApplicationFiled: October 10, 2023Publication date: February 1, 2024Inventor: Nobuhiro MAETO
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Patent number: 11862213Abstract: According to one embodiment, a magnetic disk device includes a disk that has a track including a first servo sector and a second servo sector that is different from the first servo sector, a head that writes data to the disk and reads data from the disk, and a controller that records first signal strength record data related to a signal strength at which first target servo data that is a target of the first servo sector is read, and standardizes first signal strength data related to a signal strength at which the first target servo data is read when the first target servo data is read.Type: GrantFiled: July 14, 2022Date of Patent: January 2, 2024Assignees: KABUSHIKI KAISHA TOSHIBA, TOSHIBA ELECTRONIC DEVICES & STORAGE CORPORATIONInventor: Nobuhiro Maeto
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Patent number: 11817123Abstract: According to one embodiment, a magnetic disk device including a disk, a head which writes data to the disk and reads data from the disk, and a controller which sets a first DOL for a first sector group and a second DOL for a second sector group to different values, the first sector group including one or more first sectors and a first parity sector, the first sectors which allow an error correction process to be performed for each track based on the first parity sector, and are continuously arranged in a circumferential direction of the disk from the first parity sector, the second sector group including one or more second sectors which allow no error correction process to be performed for each track, and are continuously arranged in the circumferential direction.Type: GrantFiled: August 15, 2022Date of Patent: November 14, 2023Assignees: Kabushiki Kaisha Toshiba, Toshiba Electronic Devices & Storage CorporationInventor: Nobuhiro Maeto
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Publication number: 20230274762Abstract: According to one embodiment, a magnetic disk device includes a disk that has a track including a first servo sector and a second servo sector that is different from the first servo sector, a head that writes data to the disk and reads data from the disk, and a controller that records first signal strength record data related to a signal strength at which first target servo data that is a target of the first servo sector is read, and standardizes first signal strength data related to a signal strength at which the first target servo data is read when the first target servo data is read.Type: ApplicationFiled: July 14, 2022Publication date: August 31, 2023Inventor: Nobuhiro Maeto
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Publication number: 20230197112Abstract: According to one embodiment, a magnetic disk device including a disk, a head which writes data to the disk and reads data from the disk, and a controller which sets a first DOL for a first sector group and a second DOL for a second sector group to different values, the first sector group including one or more first sectors and a first parity sector, the first sectors which allow an error correction process to be performed for each track based on the first parity sector, and are continuously arranged in a circumferential direction of the disk from the first parity sector, the second sector group including one or more second sectors which allow no error correction process to be performed for each track, and are continuously arranged in the circumferential direction.Type: ApplicationFiled: August 15, 2022Publication date: June 22, 2023Inventor: Nobuhiro MAETO
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Patent number: 11646051Abstract: According to one embodiment, a magnetic disk device includes a disk that includes a first track, a head that includes a heater, writes data to the disk, and reads data from the disk, and a controller configured to set a variation of a parameter related to a write process for the disk within one round of the first track to suppress a variation of an evaluation index corresponding to a write/read processing characteristic within one round of the first track.Type: GrantFiled: February 3, 2022Date of Patent: May 9, 2023Assignees: Kabushiki Kaisha Toshiba, Toshiba Electronic Devices & Storage CorporationInventors: Hiroshi Isokawa, Nobuhiro Maeto
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Publication number: 20230061895Abstract: According to one embodiment, a magnetic disk device includes a disk that includes a first track, a head that includes a heater, writes data to the disk, and reads data from the disk, and a controller configured to set a variation of a parameter related to a write process for the disk within one round of the first track to suppress a variation of an evaluation index corresponding to a write/read processing characteristic within one round of the first track.Type: ApplicationFiled: February 3, 2022Publication date: March 2, 2023Inventors: Hiroshi ISOKAWA, Nobuhiro MAETO
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Patent number: 11545183Abstract: According to one embodiment, a magnetic disk device includes a disk, a head that writes data to the disk and reads data from the disk, and a controller that corrects a first signal into a first likelihood value by machine learning based on a correct learning signal set with a likelihood other than 1 and an incorrect learning signal set with a likelihood other than 0 and executes error correction processing based on a second likelihood value according to the first signal and the first likelihood value.Type: GrantFiled: March 10, 2021Date of Patent: January 3, 2023Assignees: KABUSHIKI KAISHA TOSHIBA, TOSHIBA ELECTRONIC DEVICES & STORAGE CORPORATIONInventor: Nobuhiro Maeto
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Patent number: 11532321Abstract: According to one embodiment, a magnetic disk device including a disk, a head that writes data with respect to the disk and reads data from the disk, and a controller that overwrites a second track on a first track in a radial direction of the disk, performs first alternative processing of recording a first user sector in a first region when writing of the first user sector available by a user in the first track is disabled, and performs second alternative processing different from the first alternative processing of recording a first parity sector in a second region when writing of the first parity sector acquired by an XOR operation in the first track is disabled.Type: GrantFiled: January 28, 2022Date of Patent: December 20, 2022Assignees: KABUSHIKI KAISHA TOSHIBA, TOSHIBA ELECTRONIC DEVICES & STORAGE CORPORATIONInventor: Nobuhiro Maeto
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Publication number: 20220392487Abstract: According to one embodiment, a magnetic disk device including a disk, a head that writes data with respect to the disk and reads data from the disk, and a controller that overwrites a second track on a first track in a radial direction of the disk, performs first alternative processing of recording a first user sector in a first region when writing of the first user sector available by a user in the first track is disabled, and performs second alternative processing different from the first alternative processing of recording a first parity sector in a second region when writing of the first parity sector acquired by an XOR operation in the first track is disabled.Type: ApplicationFiled: January 28, 2022Publication date: December 8, 2022Inventor: Nobuhiro MAETO
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Patent number: 11508399Abstract: According to one embodiment, a magnetic disk device includes a disk, a head, and a controller setting a rewrite threshold value for executing a rewrite process of different tracks in a first sector group including at least one first sector continuous from a first parity sector in which error correction processing in units of tracks is executable based on the first parity sector and including the first parity sector, and a second sector group including at least one second sector continuous in which the error correction processing in units of tracks is unexecutable, and rewriting the first sector group and the second sector group with different frequencies.Type: GrantFiled: August 20, 2021Date of Patent: November 22, 2022Assignees: KABUSHIKI KAISHA TOSHIBA, TOSHIBA ELECTRONIC DEVICES & STORAGE CORPORATIONInventor: Nobuhiro Maeto
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Publication number: 20220293129Abstract: According to one embodiment, a magnetic disk device includes a disk, a head, and a controller setting a rewrite threshold value for executing a rewrite process of different tracks in a first sector group including at least one first sector continuous from a first parity sector in which error correction processing in units of tracks is executable based on the first parity sector and including the first parity sector, and a second sector group including at least one second sector continuous in which the error correction processing in units of tracks is unexecutable, and rewriting the first sector group and the second sector group with different frequencies.Type: ApplicationFiled: August 20, 2021Publication date: September 15, 2022Inventor: Nobuhiro Maeto