公开(公告)号：US11004468B2

公开(公告)日：2021-05-11

申请号：US16808429

申请日：2020-03-04

申请人： Kabushiki Kaisha Toshiba ,  Toshiba Electronic Devices & Storage Corporation

发明人： Nobuhiro Maeto ,  Yusuke Tomoda

IPC分类号： G11B20/12 ,  G11B20/10 ,  G11B27/10

摘要： According to one embodiment, a magnetic disk device includes a disk, a head which writes data to the disk and reads data from the disk, and a controller which increases a first recording density of data to be written to a first sector having a first overwrite in the first sector and reduces a second recording density of data to be written to a second sector having a second overwrite different from the first overwrite, on a first track of the disk.

公开(公告)号：US10910013B1

公开(公告)日：2021-02-02

申请号：US16804537

申请日：2020-02-28

申请人： Kabushiki Kaisha Toshiba ,  Toshiba Electronic Devices & Storage Corporation

发明人： Takayuki Kawabe ,  Takeyori Hara ,  Nobuhiro Maeto

IPC分类号： G11B21/18 ,  G11B20/18 ,  G11B20/12 ,  G11B5/58

摘要： According to one embodiment, a magnetic disk device includes a disk including a first track including a first sector, a second sector, and a first parity sector, a head, and a controller configured to, when writing a second track adjacent to the first track in the first direction, even if, in a third sector of the second track adjacent to the first sector in the first direction, a first upper limit in a second direction opposite to the first direction, continue the processing of writing data to the third sector, and if, in a fourth sector adjacent to the second sector in the first direction, a second upper limit in the second direction, stop the processing of writing data to the fourth sector.

公开(公告)号：US20200211588A1

公开(公告)日：2020-07-02

申请号：US16560438

申请日：2019-09-04

申请人： Kabushiki Kaisha Toshiba ,  Toshiba Electronic Devices & Storage Corporation

发明人： Nobuhiro Maeto ,  Takeyori Hara ,  Takayuki Kawabe

IPC分类号： G11B5/596

摘要： According to one embodiment, a magnetic disk device includes a disk including a plurality of servo data items, a head including a write head which writes data to the disk, and a first read head and a second read head which read data from the disk, and a controller configured to position the head based on a first signal in which write data positioned between the servo data items of the disk is read by the first read head, and a second signal in which the write data is read by the second read head separated from the first read head in a radial direction of the disk.

公开(公告)号：US20170270963A1

公开(公告)日：2017-09-21

申请号：US15252612

申请日：2016-08-31

申请人： Kabushiki Kaisha Toshiba

发明人： Nobuhiro Maeto

IPC分类号： G11B20/18 ,  G06F11/10

CPC分类号： G11B20/1833 ,  G11B20/1866

摘要： According to one embodiment, sector groups are generated from M (M is an integer of 2 or larger) sector data, one parity sector unit is generated from N (N is an integer of 1 or larger) sector groups in which the M sector data are interleaved for the individual sector groups, and one parity sector group in which K (K is as integer of 2 or larger) parity sectors corresponding to K parity sector units are turned into long sector is generated.

公开(公告)号：US20230274762A1

公开(公告)日：2023-08-31

申请号：US17865226

申请日：2022-07-14

申请人： Kabushiki Kaisha Toshiba ,  Toshiba Electronic Devices & Storage Corporation

发明人： Nobuhiro Maeto

IPC分类号： G11B5/596 ,  G11B20/12

CPC分类号： G11B5/59644 ,  G11B20/1217 ,  G11B2020/1281 ,  G11B2220/2516

摘要： 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.

公开(公告)号：US11545183B2

公开(公告)日：2023-01-03

申请号：US17197283

申请日：2021-03-10

申请人： Kabushiki Kaisha Toshiba ,  Toshiba Electronic Devices & Storage Corporation

发明人： Nobuhiro Maeto

IPC分类号： H03M13/00 ,  G11B20/18 ,  G11B19/04 ,  G06N3/08

摘要： 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.

公开(公告)号：US20220076701A1

公开(公告)日：2022-03-10

申请号：US17197283

申请日：2021-03-10

申请人： Kabushiki Kaisha Toshiba ,  Toshiba Electronic Devices & Storage Corporation

发明人： Nobuhiro Maeto

IPC分类号： G11B20/18 ,  G11B19/04 ,  G06N3/08

摘要： 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.

公开(公告)号：US10923144B2

公开(公告)日：2021-02-16

申请号：US16554129

申请日：2019-08-28

申请人： Kabushiki Kaisha Toshiba ,  Toshiba Electronic Devices & Storage Corporation

发明人： Nobuhiro Maeto

IPC分类号： G11B5/54 ,  G11B5/56 ,  G11B5/012 ,  G11B20/20 ,  G11B21/08

摘要： According to one embodiment, a magnetic disk device includes a disk, a head including a write head that writes data to the disk, and a first read head and a second read head that read data from the disk, and a controller that, in reading a first track of a first region of the disk, positions a middle portion of the first read head and the second read head at a first track center of the first track, and in reading a second track of a second region of the disk different from the first region, positions any one of the first read head and the second read head at a second track center of the second track.

公开(公告)号：US10650860B2

公开(公告)日：2020-05-12

申请号：US16275967

申请日：2019-02-14

申请人： KABUSHIKI KAISHA TOSHIBA ,  TOSHIBA ELECTRONIC DEVICES & STORAGE CORPORATION

发明人： Nobuhiro Maeto ,  Akihiko Takeo

IPC分类号： G11B11/08 ,  G11B21/08 ,  G11B5/127 ,  G11B21/10 ,  G11B5/596

摘要： According to one embodiment, a magnetic disk device includes a disk, a head for writing data to the disk and reading data from the disk, and a controller configured to detect a positioning error of the head as the head is writing the data in a first track of the disk, and change a first threshold value for interrupting the writing based on one or more evaluation values corresponding to a possibility of correcting error data in the first track of the disk. The controller interrupts the writing when detecting the positioning error of the head writing the first track that exceeds the first threshold value.

公开(公告)号：US11646051B2

公开(公告)日：2023-05-09

申请号：US17591957

申请日：2022-02-03

申请人： KABUSHIKI KAISHA TOSHIBA ,  TOSHIBA ELECTRONIC DEVICES & STORAGE CORPORATION

发明人： Hiroshi Isokawa ,  Nobuhiro Maeto

IPC分类号： G11B20/18 ,  G11B5/012 ,  G11B5/00

CPC分类号： G11B5/012 ,  G11B2005/0021

摘要： 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.