Kabushiki Kaisha Toshiba

Toshiba Electronic Devices & Storage Corporation

Showa Denko K.k.

Tohoku University

Other

Tdk Corporation

Toshiba Corporation

Akihiko Takeo

Kenichiro Yamada

Katsuhiko Koui

Kaori Kimura

Tomoyuki Maeda

Naoyuki Narita

Kazutaka Takizawa

Takeshi Iwasaki

Akira Watanabe

Hitoshi Iwasaki

Migaku Takahashi

Yusuke Tomoda

Shin Saito

Masaya Ohtake

Masayuki Takagishi

Shuichi Murakami

Tomomi Funayama

Mariko Shimizu

Masahiro Takashita

Yuzo Sasaki

Gohei Kurokawa

Atsushi Hashimoto

Gaku Koizumi

Satoshi Shirotori

Tomoko Taguchi

Yuka Aoyagi

Hiroyuki Suzuki

Masatoshi Sakurai

Takuya Matsumoto

Takeyori Hara

Koji Yano

Kazuto Kashiwagi

Daisuke Sudo

Yuichi Yamada

Tatsuo Nitta

Shinichi Ishibashi

Norihito Fujita

Kazuo Chokki

Mariko Kitazaki

Tsuyoshi Onitsuka

Tatsurou Sasamoto

Min Li

Yuchen Zhou

Hideaki Fukuzawa

Kunliang Zhang

Akira Kikitsu

Moris Musa Dovek

Hiromi Yuasa

Yoshihiko Fuji

Tetsuya Roppongi

Michiko Hara

Kenichi Takano

Junichi Akiyama

Soichi Oikawa

Takayuki Kawabe

Haruyuki Morita

Joe Smyth

Shinobu Sugimura

Mikio Matsuzaki

Yoichiro Tanaka

Nobuhiro Maeto

Hiroshi Isokawa

Kazuhito Shimomura

Ryuji Sakaguchi

Ken Inoue

Shinichi Horinouchi

Tatsu Komatsuda

Noayuki Narita

Shingo Sasaki

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.

Magnetic disk device

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.

Magnetic recording/reproducing device and magnetic recording/reproducing method

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.

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.

Magnetic disk device and rewrite processing method

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.

Magnetic disk device having first and second assist elements and write operation method

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.

Magnetic disk drive and head adjusting method

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.

Magnetic disk device having two regions of different thicknesses

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=Vb&#x2212;a&#xd7;1/log(t)&#xd7;log(RH)&#xd7;log(P).

Magnetic recording and reproducing device having a magnetic recording head including a magnetic flux control layer between a main magnetic pole and an auxiliary magnetic pole

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.

Magnetic recording and reading apparatus and magnetic recording method

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.

Magnetic head and disk device having gap layers with different magnetic relative permeabilities

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.

Magnetic disk device and write processing method

Magnetic head having difference skew angles at different regions on magnetic recording disk

According to one embodiment, a magnetic recording head includes a magnetic pole, a stacked body, and a first non-magnetic layer. The stacked body includes a first magnetic layer, a second magnetic layer provided between the first magnetic layer and the magnetic pole, and a non-magnetic intermediate layer provided between the first magnetic layer and the second magnetic layer. The first non-magnetic layer is provided between the second magnetic layer and the magnetic pole, and contacts the magnetic pole and the second magnetic layer. The first magnetic layer has a first thickness and a first saturation magnetic flux density. The second magnetic layer has a second thickness and a second saturation magnetic flux density. A second product of the second thickness and the second saturation magnetic flux density is larger than a first product of the first thickness and the first saturation magnetic flux density.

Magnetic recording head with specified thickness and saturation magnetic flux density products for STO magnetic layers

According to one embodiment, a magnetic disk device conforming to perpendicular magnetic recording includes a magnetic disk, a recording head, and a controller. The head includes a main magnetic pole, a return magnetic pole, a recording coil, and a conductive member in which end surfaces are connected to opposed surfaces of a write gap which is opposed to a distal portion of the main magnetic pole and a distal portion of the return magnetic pole, and a resistance value varies. The controller applies a current to the recording coil to excite the magnetic flux in the recording operation, and applies a current at a constant voltage to the magnetic circuit via the comductive member.

Magnetic disk device which controls a recording operation and a non-recording operation of a recording head and a recording head control method of the magnetic disk device

Growing community of inventors

Kunitachi, Japan

Akihiko Takeo