Patents by Inventor Akihiko Takeo
Akihiko Takeo 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).
-
Patent number: 11887633Abstract: According to one embodiment, a magnetic disk device comprising a magnetic disk, a magnetic head, and a controller that registers an address and a positioning error, determines whether or not a positioning error of a second sector that is two tracks ahead in a radial direction of a first sector to which a data is written is registered, and when the positioning error of the second sector is registered, sets a first threshold that allows a write operation for a positioning error of the first sector based on the positioning error of the second sector, and determines whether or not the positioning error of the first sector exceeds the first threshold, and stops the write operation when the positioning error of the first sector exceeds the first threshold.Type: GrantFiled: September 9, 2022Date of Patent: January 30, 2024Assignees: KABUSHIKI KAISHA TOSHIBA, TOSHIBA ELECTRONIC DEVICES & STORAGE CORPORATIONInventors: Takayuki Kawabe, Akihiko Takeo
-
Patent number: 11862206Abstract: According to one embodiment, a magnetic recording/reproducing device includes a plurality of magnetic recording medium each including a recording surface, a plurality of assisted magnetic recording heads each provided with the recording surface in order to perform assisted recording, and an assisting amount adjustment part connected to the assisted magnetic recording heads in order to adjust an assisting amount of each assisted magnetic recording head corresponding to a recording capacity of the recording surface.Type: GrantFiled: July 8, 2022Date of Patent: January 2, 2024Assignees: Kabushiki Kaisha Toshiba, Toshiba Electronic Devices & Storage CorporationInventors: Kaori Kimura, Masaya Ohtake, Akihiko Takeo
-
Publication number: 20230282228Abstract: According to one embodiment, a magnetic disk device comprising a magnetic disk, a magnetic head, and a controller that registers an address and a positioning error, determines whether or not a positioning error of a second sector that is two tracks ahead in a radial direction of a first sector to which a data is written is registered, and when the positioning error of the second sector is registered, sets a first threshold that allows a write operation for a positioning error of the first sector based on the positioning error of the second sector, and determines whether or not the positioning error of the first sector exceeds the first threshold, and stops the write operation when the positioning error of the first sector exceeds the first threshold.Type: ApplicationFiled: September 9, 2022Publication date: September 7, 2023Inventors: Takayuki Kawabe, Akihiko Takeo
-
Patent number: 11670331Abstract: According to one embodiment, a magnetic disk device includes a rotatable disk-shaped recording medium, a magnetic head including a write head having a main magnetic pole that applies a recording magnetic field to the recording medium, an assist element that assists magnetic recording by the main magnetic pole, and a plurality of thermal actuators that control a head gradient with respect to the recording medium, and a controller which includes a detection unit configured to detect deterioration of the magnetic head, and changes a head gradient of the magnetic head by the thermal actuator according to the detected deterioration.Type: GrantFiled: February 15, 2022Date of Patent: June 6, 2023Assignees: Kabushiki Kaisha Toshiba, Toshiba Electronic Devices & Storage CorporationInventors: Kaori Kimura, Akihiko Takeo, Takuya Matsumoto
-
Publication number: 20230169993Abstract: According to one embodiment, a magnetic recording/reproducing device includes a plurality of magnetic recording medium each including a recording surface, a plurality of assisted magnetic recording heads each provided with the recording surface in order to perform assisted recording, and an assisting amount adjustment part connected to the assisted magnetic recording heads in order to adjust an assisting amount of each assisted magnetic recording head corresponding to a recording capacity of the recording surface.Type: ApplicationFiled: July 8, 2022Publication date: June 1, 2023Inventors: Kaori KIMURA, Masaya OHTAKE, Akihiko TAKEO
-
Publication number: 20230074588Abstract: According to one embodiment, a magnetic disk device includes a rotatable disk-shaped recording medium, a magnetic head including a write head having a main magnetic pole that applies a recording magnetic field to the recording medium, an assist element that assists magnetic recording by the main magnetic pole, and a plurality of thermal actuators that control a head gradient with respect to the recording medium, and a controller which includes a detection unit configured to detect deterioration of the magnetic head, and changes a head gradient of the magnetic head by the thermal actuator according to the detected deterioration.Type: ApplicationFiled: February 15, 2022Publication date: March 9, 2023Inventors: Kaori KIMURA, Akihiko TAKEO, Takuya MATSUMOTO
-
Patent number: 11594250Abstract: According to one embodiment, a magnetic disk device includes a disk having a first region in which a plurality of tracks is written and a second region that is positioned with a gap in a first direction of the radial direction of the first region, and in which a plurality of tracks is overwritten in the first direction, a head, and a controller that offsets part of a plurality of tracks which is overwritten in the second region in a second direction opposite the first direction to perform rewriting.Type: GrantFiled: March 10, 2021Date of Patent: February 28, 2023Assignees: KABUSHIKI KAISHA TOSHIBA, TOSHIBA ELECTRONIC DEVICES & STORAGE CORPORATIONInventors: Yusuke Tomoda, Akihiko Takeo
-
Patent number: 11568892Abstract: According to one embodiment, a magnetic disk device includes: a disk; a head including a main magnetic pole, a write shield that faces the main magnetic pole in a first direction and is separated from the main magnetic pole by a gap, a first assist element that is disposed in the gap and a second assist element that is disposed in the gap and is positioned relative to the first assist element in a second direction intersecting the first direction; and a controller configured to: cause a first assist energy from the first assist element to be applied to the disk and affect a coercive force of the disk; and cause a second assist energy from the second assist element to be applied to the disk and affect a coercive force of the disk, wherein the first assist energy is different from the second assist energy.Type: GrantFiled: August 6, 2021Date of Patent: January 31, 2023Assignees: KABUSHIKI KAISHA TOSHIBA, TOSHIBA ELECTRONIC DEVICES & STORAGE CORPORATIONInventors: Hiroyuki Suzuki, Akihiko Takeo
-
Publication number: 20220068302Abstract: According to one embodiment, a magnetic disk device includes a disk having a first region in which a plurality of tracks is written and a second region that is positioned with a gap in a first direction of the radial direction of the first region, and in which a plurality of tracks is overwritten in the first direction, a head, and a controller that offsets part of a plurality of tracks which is overwritten in the second region in a second direction opposite the first direction to perform rewriting.Type: ApplicationFiled: March 10, 2021Publication date: March 3, 2022Inventors: Yusuke Tomoda, Akihiko Takeo
-
Publication number: 20210366517Abstract: According to one embodiment, a magnetic disk device includes: a disk; a head including a main magnetic pole, a write shield that faces the main magnetic pole in a first direction and is separated from the main magnetic pole by a gap, a first assist element that is disposed in the gap and a second assist element that is disposed in the gap and is positioned relative to the first assist element in a second direction intersecting the first direction; and a controller configured to: cause a first assist energy from the first assist element to be applied to the disk and affect a coercive force of the disk; and cause a second assist energy from the second assist element to be applied to the disk and affect a coercive force of the disk, wherein the first assist energy is different from the second assist energy.Type: ApplicationFiled: August 6, 2021Publication date: November 25, 2021Inventors: Hiroyuki SUZUKI, Akihiko TAKEO
-
Patent number: 11120822Abstract: A magnetic disk drive includes first and second disks having respective first and second surfaces, a first head including a first write head that writes data on the first surface at a first recording density, and a first assist element that generates a first energy for increasing a write performance by the first write head, a second head including a second write head that writes data on the second surface at a second recording density, and a second assist element that generates a second energy for increasing a write performance by the second write head, and a controller that changes one of the first and second recording densities based on a first recording capacity up to which the first head is capable of writing on the first disk, a second recording capacity up to which the second head is capable of writing on the second disk, and a target capacity.Type: GrantFiled: August 26, 2020Date of Patent: September 14, 2021Assignees: KABUSHIKI KAISHA TOSHIBA, TOSHIBA ELECTRONIC DEVICES & STORAGE CORPORATIONInventors: Masaya Ohtake, Akihiko Takeo
-
Patent number: 11114127Abstract: According to one embodiment, a magnetic disk device includes: a disk; a head including a main magnetic pole, a write shield that faces the main magnetic pole in a first direction and is separated from the main magnetic pole by a gap, a first assist element that is disposed in the gap and a second assist element that is disposed in the gap and is positioned relative to the first assist element in a second direction intersecting the first direction; and a controller configured to: cause a first assist energy from the first assist element to be applied to the disk and affect a coercive force of the disk; and cause a second assist energy from the second assist element to be applied to the disk and affect a coercive force of the disk, wherein the first assist energy is different from the second assist energy.Type: GrantFiled: March 2, 2020Date of Patent: September 7, 2021Assignees: KABUSHIKI KAISHA TOSHIBA, TOSHIBA ELECTRONIC DEVICES & STORAGE CORPORATIONInventors: Hiroyuki Suzuki, Akihiko Takeo
-
Publication number: 20210256996Abstract: A magnetic disk drive includes first and second disks having respective first and second surfaces, a first head including a first write head that writes data on the first surface at a first recording density, and a first assist element that generates a first energy for increasing a write performance by the first write head, a second head including a second write head that writes data on the second surface at a second recording density, and a second assist element that generates a second energy for increasing a write performance by the second write head, and a controller that changes one of the first and second recording densities based on a first recording capacity up to which the first head is capable of writing on the first disk, a second recording capacity up to which the second head is capable of writing on the second disk, and a target capacity.Type: ApplicationFiled: August 26, 2020Publication date: August 19, 2021Inventors: Masaya OHTAKE, Akihiko TAKEO
-
Patent number: 10964344Abstract: According to one embodiment, a magnetic disk device includes a disk including a first region and a second region different from the first region, a head that writes data on the disk and reads data from the disk, an actuator that positions the head on the disk, and a controller which positions the head by driving the actuator and writes data in the first region and the second region with the head, a skew angle of the head with respect to a circumferential direction of the disk varying within a first angle in the first region, and varying, in the second region, from a second angle larger than the first angle to a third angle larger than the first angle and the second angle.Type: GrantFiled: February 11, 2020Date of Patent: March 30, 2021Assignees: Kabushiki Kaisha Toshiba, Toshiba Electronic Devices & Storage CorporationInventors: Daisuke Sudo, Tatsurou Sasamoto, Takeyori Hara, Akihiko Takeo, Kazuo Chokki, Tatsuo Nitta
-
Publication number: 20210090605Abstract: According to one embodiment, a magnetic disk device includes: a disk; a head including a main magnetic pole, a write shield that faces the main magnetic pole in a first direction and is separated from the main magnetic pole by a gap, a first assist element that is disposed in the gap and a second assist element that is disposed in the gap and is positioned relative to the first assist element in a second direction intersecting the first direction; and a controller configured to: cause a first assist energy from the first assist element to be applied to the disk and affect a coercive force of the disk; and cause a second assist energy from the second assist element to be applied to the disk and affect a coercive force of the disk, wherein the first assist energy is different from the second assist energy.Type: ApplicationFiled: March 2, 2020Publication date: March 25, 2021Inventors: Hiroyuki SUZUKI, Akihiko TAKEO
-
Patent number: 10854222Abstract: According to one embodiment, a magnetic recording and reproducing device includes a magnetic flux control layer provided between a main magnetic pole and an auxiliary magnetic pole, and a protective layer provided on an ABS of the auxiliary magnetic pole. The magnetic flux control layer includes an adjustment layer formed of a magnetic material including one of Fe, Co or Ni and is provided between a first conductive layer and a second conductive layer, and generates a spin torque and inverts a direction of magnetization in the adjustment layer, when current is supplied. A voltage Vb applied to the magnetic flux control layer is lower than a voltage Vba represented by an expression (1), Vba=Vb0?a×1/log(t)×log(RH)×log(PO2).Type: GrantFiled: February 4, 2019Date of Patent: December 1, 2020Assignees: Kabushiki Kaisha Toshiba, Toshiba Electronic Devices & Storage CorporationInventors: Yusuke Tomoda, Kaori Kimura, Akihiko Takeo
-
Publication number: 20200243108Abstract: A magnetic head includes a main magnetic pole, a write shield separated from the main magnetic pole by a write gap, a first side shield that is separated from the main magnetic pole by a first side gap, a second side shield that is separated from the main magnetic pole by a second side gap, a first layer that has a first magnetic relative permeability and is disposed in the write gap between the main magnetic pole and the write shield, and a second layer that has a second magnetic relative permeability and is disposed in the first side gap and the second side gap, wherein the first magnetic relative permeability is smaller than the second magnetic relative permeability.Type: ApplicationFiled: April 14, 2020Publication date: July 30, 2020Inventors: Masaya OHTAKE, Akihiko TAKEO, Naoyuki NARITA, Gaku KOIZUMI, Yusuke TOMODA, Tomoyuki MAEDA
-
Publication number: 20200176020Abstract: According to one embodiment, a magnetic recording and reading apparatus has a magnetic head and a system controlling a flying height of the magnetic head. The system includes a main control unit, a resistance measurement unit which measures a resistance value of a magnetic flux control layer, a calculation unit which obtains a resistance value change rate with respect to an initial resistance value, a determination unit which determines a flying height for recording corresponding to the resistance value change rate, and a flying height control unit which controls a flying height of the magnetic head.Type: ApplicationFiled: June 28, 2019Publication date: June 4, 2020Inventors: Takuya Matsumoto, Akihiko Takeo
-
Publication number: 20200176026Abstract: According to one embodiment, a magnetic disk device includes a disk including a first region and a second region different from the first region, a head that writes data on the disk and reads data from the disk, an actuator that positions the head on the disk, and a controller which positions the head by driving the actuator and writes data in the first region and the second region with the head, a skew angle of the head with respect to a circumferential direction of the disk varying within a first angle in the first region, and varying, in the second region, from a second angle larger than the first angle to a third angle larger than the first angle and the second angle.Type: ApplicationFiled: February 11, 2020Publication date: June 4, 2020Inventors: Daisuke Sudo, Tatsurou Sasamoto, Takeyori Hara, Akihiko Takeo, Kazuo Chokki, Tatsuo Nitta
-
Patent number: 10672419Abstract: According to one embodiment, a magnetic recording and reading apparatus has a magnetic head and a system controlling a flying height of the magnetic head. The system includes a main control unit, a resistance measurement unit which measures a resistance value of a magnetic flux control layer, a calculation unit which obtains a resistance value change rate with respect to an initial resistance value, a determination unit which determines a flying height for recording corresponding to the resistance value change rate, and a flying height control unit which controls a flying height of the magnetic head.Type: GrantFiled: June 28, 2019Date of Patent: June 2, 2020Assignees: Kabushiki Kaisha Toshiba, Toshiba Electronic Devices & Storage CorporationInventors: Takuya Matsumoto, Akihiko Takeo