Hitachi, Ltd.

Hgst Netherlands, B.v.

Hitachi Global Storage Technologies Japan, Ltd.

Hitachi Global Storage Technologies Netherlands B.v.

Hitachi Global Storage Technologies

Kyo Akagi

Hisashi Takano

Mikio Suzuki

Masaaki Futamoto

Yoshibumi Matsuda

Takeshi Nakao

Yoshinori Miyamura

Fumio Kugiya

Hirotsugu Fukuoka

Takayuki Munemoto

Tokuho Takagaki

Toshio Kobayashi

Hideo Tanabe

Naoki Koyama

Kazuo Shiiki

Masahiro Kitada

Isamu Yuito

Ryoichi Nakatani

Noboru Shimizu

Eijin Moriwaki

Atsushi Saito

Takehiko Hamaguchi

Takashi Yamaguchi

Yoshihiro Shiroishi

Motoyasu Tsunoda

Takayuki Ichihara

Masafumi Mochizuki

Kouki Uefune

Masaaki Matsumoto

Takashi Kawabe

Masuo Umemoto

Kouichirou Wakabayashi

Yasuhiro Kato

Yosuke Seo

Reijiro Tsuchiya

Hiroyasu Tanabe

Akira Iida

Yong-Kweon Kim

Koki Uefune

Katsuro Watanabe

Terumi Takashi

Toshihisa Tsukada

Hideki Sawaguchi

Nobuyuki Inaba

Naoki Satoh

Takako Hayakawa

Kenji Mori

Masahiro Ojima

Shozo Saegusa

Hajime Aoi

Hiroki Kitahori

Yasuhide Ouchi

Hideki Zaitsu

Kiyoshi Matsumoto

Ryuji Tsuchiyama

Naoto Ito

Hiroshi Ikekame

Yosuke Hamada

Masaki Odai

Makoto Aihara

Takahiro Nakagawa

Atsushi Okuyama

Shuji Nishida

Hiroshi Fukuyama

Satoshi Hashimoto

Yasuo Kojima

Toshiaki Satoh

Mao Nishiyama

Kensuke Ishiwata

Kazunari Usui

Takeshi Nakano

Takayuki Honda

A method for producing a magnetic disk device includes injecting replacement gas into a hermetically-sealed enclosure by means of an injection nozzle while suctioning gas from inside of the hermetically-sealed enclosure by means of a suction nozzle in such a way that the gas pressure inside of the enclosure does not fall below the vapor pressure of the organic compounds present inside of the enclosure, wherein the hermetically-sealed enclosure houses within a magnetic disk for storing data, a magnetic head for writing/reading the data, and an actuator for moving the magnetic head relative to the magnetic disk, and wherein a gas injection port and a gas expulsion port are formed in the hermetically-sealed enclosure and provide communication between the inside and outside, wherein an injection nozzle is disposed at the gas injection port and a suction nozzle is disposed at the gas expulsion port.

Producing a magnetic disk device

The embodiments of the present invention relate to a shingled magnetic recording system having a magnetic recording medium that has a magnetization easy axis in the recording layer of the medium that is oriented in from the bottom surface to the top surface of the recording layer. Additionally, a magnetization easy axis in the recording layer of the medium is inclined with respect to the recording track width direction.

Magnetic recording with tilted media in the cross track direction

In one embodiment, a method includes spiral writing a DC pattern onto a magnetic disk medium using a writer of a magnetic head while moving the magnetic head in a direction about parallel to a radial direction of the magnetic disk medium while rotating the magnetic disk medium, reading the magnetic disk medium while moving the magnetic head in the direction about parallel to the radial direction of the magnetic disk medium while rotating the magnetic disk medium, and calculating a track pitch interval between data tracks of the magnetic disk medium based on the reading of the magnetic disk medium. In another embodiment, a magnetic disk medium includes a DC spiral pattern in a radial region further outward and/or a radial region further inward than a radial region where data is recorded.

Track pitch variation measurement method using spiral DC pattern writing

SMR disk drives are described that adjust track pitch or magnetic write width to compensate for external temperature effects. In one embodiment track pitch is increased when the media temperature increases. The temperature of magnetic media during write operations can be determined from the drives' temperature sensor. In other embodiments track pitch is adjusted based on the magnetic write width (MWW) which is determined from read-back testing of previously written data tracks. In an alternative embodiment, the width of the MWW is adjusted instead of the track pitch. The various factors that affect the MWW that can be used to increase or decrease the MWW, including write current characteristics and when available thermal-assistance parameters.

Dynamic track pitch control for shingled magnetic recording (SMR)

Embodiments of the present invention provide a servo write medium, method and device for writing servo information by self servo write on the servo region formed from a flat section of the discrete track medium. The recording or write device yields the same servo characteristics as magnetic servo writing, is superior to pre-patterned servo, and delivers a greater write storage capacity with an even higher recording density. According to one embodiment, a self servo write method is used to write servo information on a flat section formed on a patterned disk on which discrete tracks are formed. Timing detection patterns (grooves) required for controlling the timing along the periphery during self servo write are formed by pre-patterning on the disk, and RRO error signals used for positioning control along the radius are written in the servo information on a flat section of the disk.

Magnetic recording media, method for servowriting on same, and hard disk drive

Embodiments of the present invention relate to a method for manufacturing a magnetic disk unit, the method including a step of writing servo data into the magnetic disk while introducing a low-density gas having a lower density than air into the enclosure. In one embodiment, the magnetic disk unit is comprised of a magnetic disk, a magnetic head, and a voice coil motor which are accommodated in the hermetically sealed enclosure. The enclosure has a gas inlet and a gas outlet, which are provided respectively with filters attached thereto.

Magnetic disk unit and manufacturing method thereof

Embodiments in accordance with the present invention erase a desired area on a recording surface of disk or disk drive apparatus. According to an embodiment, a hard disk drive (HDD) performs erase on a recording surface by moving a head element unit at one-half a servo track pitch with reference to a servo address. Before actual erase is started on the recording surface, the HDD generates a management table configured based on servo addresses from a management table configured based on data tracks. At an erase process, the HDD sets parameters in accordance with the zone and skips a management area with reference to this management table based on the servo addresses.

Method for erase process on recording surface of disk and disk drive apparatus

A hard disk drive and magnetic medium including a servo area, a data area divided into a plurality of sector blocks and at least one micro-servo area disposed between two sector blocks. There may be a micro-servo area immediately preceding each of the plurality of sector blocks. The micro-servo areas include an address mark and a track parity check code that allow the detection of an external shock that causes the recording (write) head to skip to an adjacent track in the hard disk medium. The micro-servo area is smaller than the servo areas, and various numbers of different track parity check codes can be used for different resolution of shock detection. An acceleration sensor may also be provided to detect larger external shocks. By detecting various external shocks with improved accuracy, and aborting the recording operation of data if an external shock is detected, the corruption of data in adjacent tracks is substantially reduced to improve disk drive performance.

Magnetic hard disk drive

The magnetoresistance effect element is of a multilayered structure having at least magnetic layers and an intermediate layer of an insulating material, a semiconductor or an antiferromagnetic material against the magnetic layers, and the magnetoresistance effect element has terminals formed at least on the opposite magnetic layers, respectively, so that a current flows in the intermediate layer. The film surfaces of all the magnetic layers constituting the magnetoresistance effect element are opposed substantially at right angles to the recording surface of a magnetic recording medium. Therefore, the area of the magnetic layers facing the recording surface of the magnetic recording medium can be extremely reduced, and thus the magnetic field from a very narrow region of the high-density recorded magnetic recording medium can be detected by the current which has a tunneling characteristic and passes through the intermediate layer.

Method for manufacturing magnetic head device

A magnetic disk apparatus has: a magnetic disk having a magnetic film formed on a substrate; a spindle motor for rotating the magnetic disk; a magnetic head for writing/reading information on/from the magnetic disk; a supporting member for supporting the magnetic head; a driving mechanism for moving the magnetic head to a predetermined position on the magnetic disk; a magnetic writing/reading circuit for enabling the magnetic head to write/read information on/from the magnetic disk; an interface for sending/receiving signals for controlling the information to/from another information processing device, a device for detecting whether or not the magnetic disk apparatus is in operation; and mechanism for latching movable part of the magnetic disk apparatus on the basis of detection result of the detecting device.

Apparatus for locking a moveable part of a magnetic disk apparatus

Magnetic apparatus with perpendicular recording medium and head having multilayered reproducing element using tunneling effect

In a magnetic disk apparatus which is removably mounted or embedded to a host apparatus and intermittently accessed for recording/reproducing data, a RAM contained in the host apparatus is utilized for a portion or entirety of a buffer RAM for use in the intermittent access to accomplish a reduction in size and cost of the magnetic disk apparatus. In addition, the magnetic disk apparatus is controlled to rotate a magnetic disk at a variable rotational speed, and operated at a rotational speed at which the total power consumption is minimized in accordance with the capacity of the utilized buffer RAM and whether an access is made for recording or reproduction, thereby improving a power saving effect.

Magnetic disk drive which accesses host RAM

A magnetic disk apparatus includes a low-rotation mode for decreasing the revolution number of a disk, in the low-rotation mode, any control signal for decelerating the disk is not generated to permit it to be decelerated owing to inertial drive and when a detected speed falls below a target speed, the disk is accelerated to thereby realize power saving.

Magnetic disk apparatus

Apparatus for latching a magnetic disk

Growing community of inventors

Fuchu, Japan

Kyo Akagi