Kabushiki Kaisha Toshiba

Toshiba Electronic Devices & Storage Corporation

Hideo Sado

Seiji Mizukoshi

Makoto Asakura

Masahide Yatsu

Toshitaka Matsunaga

Shouji Nakajima

Katsuki Ueda

Shinichirou Kouhara

Masafumi Iwashiro

Kazuhiko Takaishi

Shinsuke Akiya

Yuichi Notake

Takuji Shimada

Takayuki Matsuzaki

Hiroyuki Suzuki

Yutaka Yoshida

Masatoshi Sakurai

Tomoko Taguchi

Yuji Sakai

Yoshinari Higashino

Koichi Aikawa

Tetsuya Tabuchi

Shinichiro Kouhara

Takahisa Hagiwara

According to one embodiment, a magnetic disk device includes a disk, a head including a write head configured to write data on the disk, a first read head, and a second read head each configured to read data from the disk, and a controller configured to detect a first error of each track pitch corresponding to each track of the disk on the basis of a first gap in a radial direction between the first read head and the second read head at each position in the radial direction of the disk, write a servo pattern on the disk on the basis of a first correction value used to correct the first error, and position the head on the basis of the servo pattern.

Magnetic disk device and head positioning method

A method for writing servo data includes: writing the servo data as the head moves outwardly towards a radial position on the disk one step at a time, wherein the same address data are written as the head moves outwardly in two consecutive steps, writing the servo data as the head moves inwardly towards the radial position one step at a time, so as to overwrite part of servo data that have been written in a previous step, wherein the same address data are written as the head moves inwardly in two consecutive steps, and writing either one of two-phase burst data, or address data and the other of said two-phase burst data, at the radial position.

Hard disk drive, manufacturing method of the same, and servo data writing method

A method for writing servo data includes writing servo data as a head moves outward on a disk one step at a time, so as to overwrite part of servo data that have been written in a previous step, writing servo data as the head moves inward on the disk one step at a time, so as to overwrite part of servo data that have been written in a previous step, and writing one of two-phase burst data, or address data and the other of said two-phase burst data, at the radial position, so as to overwrite at least part of servo data written in each last step of the writings as the head moves outward and inward. The same address data are written in two consecutive steps as the head moves outward and as the head moves inward.

According to one embodiment, a magnetic disk drive includes a disk, a first microactuator, a second microactuator and a servo controller. The disk comprises a first surface and a second surface. The first and second microactuators allow first and second heads associated with the first and second surfaces to make micromotion based on first and second operation amounts, respectively. The servo controller provides a third operation amount to the first microactuator as the first operation amount and provides an operation amount obtained by inverting a polarity of a frequency component with a particular frequency contained in the third operation amount, to the second microactuator as the second operation amount, if the third operation amount is generated as an operation amount to be provided to the first microactuator in a particular mode in which the first surface is used as a tracking surface.

Magnetic disk drive and method for controlling microactuator in magnetic disk drive

According to one embodiment, a recording device comprises: a recording medium, an arm, a positioning module, a self-servo write clock generator, and an on-track module. The positioning module positions the arm at a position at which the electromagnetic transducer detects a rotational synchronization component of an intermediate pattern comprised in the recording medium. The self-servo write clock generator generates a self-servo write clock based on the detected rotational synchronization component. The on-track module positions the electromagnetic transducer to the intermediate pattern serving as a position for starting self-servo write based on the generated self-servo write clock. Until the on-track module appropriately completes the positioning, the self-servo write clock generator sequentially changes a decoding gate interval corresponding to the intermediate pattern in accordance with the rotational synchronization component, and captures a spiral reproduction waveform.

Recording device and method for positioning electromagnetic transducer

An information correcting method includes: detecting a first pattern in a radial direction and a second pattern formed obliquely to the radial direction on a track traversing the first and second patterns; counting number of the first pattern until the count value reaches number of the first pattern in one round of the track; generating a value incremented up number of the second pattern in the one round every time an interrupt associated with detection of the second pattern is generated as number of the second pattern; calculating an ideal number from a value obtained by multiplying the number of the second pattern until the number is counted by the counted number of the detected first pattern and a number set to the second pattern with reference to the second pattern formed at a present initial position; and correcting the generated number with the ideal number.

Storage device and information correction method

According to one embodiment, a disk drive configured to write data to a disk being rotated by a spindle motor has a synchronous clock generator that generates a synchronous clock to use during the write operation. The synchronous clock generator inputs the rotational acceleration of the spindle motor, as feed-forward control value, to the feedback control system provided in the drive disk, thereby generating a clock that is synchronous with the rotational speed of the disk.

Method and apparatus for generating synchronous clock for write operation in a disk drive

According to one embodiment, a disk drive has a DTM type disk. The DTM type disk has a servo area on one recording surface. In the servo area, a servo pattern is recorded. The servo pattern is composed of a projection-depression pattern and an N- and P-pole magnetic pattern. The N- and P-pole magnetic pattern is recorded in an address-data region that contains a cylinder code.

Disk drive having a disk of discrete-track media type

According to one embodiment, a search module searches for a timing when a moving direction of a head changes in order to detect a first timing when the head collides against a stopper of a ramp during a head unload operation and a second timing when the head rebounds as a result of the collision. A calculation module calculates a rebound distance that the head has rebounded based on the first timing and the second timing.

Disk drive configured to calculate head rebound distance

According to one embodiment, a disk drive having a disk, a read head, a servo controller, and a CPU. In the disk, a multi-spiral servo pattern is recorded. The read head reproduces a hexagon-shaped detection signal from the multi-spiral servo pattern. The servo controller generates amplitudes values for respective frames, from the multi-spiral servo pattern. The CPU performs positional-error calculation by using the amplitude values for the frames. Upon detecting a positional change of the head is detected, the CPU performs the positional-error calculation by using the amplitude values generated at the time of replacing the frames with other frames, and corrects the positional error by adding an offset determined from the positional change of the head, to the result of the positional-error calculation.

Method and apparatus for head positioning using spiral servo patterns in a disk drive

According to one embodiment, a servo-writing method for use in a disk drive, in which a CPU causes a head to record final patterns in a disk, by using the multi spiral servo pattern recorded in the disk. The CPU uses a designated spiral servo pattern, positioning the head at a target position, so that the head may write the final patterns at the target position and may read sector-address data contained in the final patterns.

Method and apparatus for writing servo data, using spiral servo patterns in a disk drive

According to one embodiment, there is to provide a disk drive which calculates an error in the position of a head on the basis of concentric servo patterns. The disk drive has a disk medium on which spiral servo patterns are recorded and a read head which reads the spiral servo patterns from the disk medium. A servo controller reproduces a hexagonal burst signal from the spiral servo patterns read by the read head to generate position data associated with servo burst signals. The CPU uses the position data to perform a position error calculation.

Method and apparatus for positioning head using spiral servo pattern in a disk drive

According to one embodiment, there is to provide a servo write method of writing a multi-spiral servo pattern to a disk medium, the method including a process of writing a spiral index pattern to the disk medium, the spiral index pattern being a spiral pattern including the same region as that of a servo burst signal included in the spiral servo pattern and a region that allows the spiral index pattern to be distinguished from the spiral servo pattern, the spiral index pattern being used as a reference for a write start.

Method and apparatus for writing spiral servo pattern in a disk drive

According to one embodiment, there is provided a servo write method of writing specified servo patterns to a disk medium on the basis of a spiral servo pattern recorded on the disk medium, wherein when the spiral servo pattern is read using a head, position detecting data used to detect a radial position on the disk medium on the basis of data recorded in a sync mark region.

Method and apparatus for writing servo pattern using spiral pattern in disk drive

According to one embodiment, a disk drive includes a detection signal producing module configured to produce a detection signal by reading each of the spiral servo patterns, the spiral servo patterns being read by a head while the head scans a circumferential direction region on the disk media. A position error computation module is configured to produce servo burst signals A, B, C, and D using a plurality of frames obtained by dividing the detection signal at even time intervals, at least one burst signal of the servo burst signals being produced using at least two frames in the frames, and to compute a position error of the head based on amplitude values of the produced burst signals.

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Ome, Japan

Hideo Sado