Kabushiki Kaisha Toshiba

Katsuki Ueda

Hideo Sado

Seiji Mizukoshi

Toshitaka Matsunaga

Shouji Nakajima

Masahide Yatsu

Shinichirou Kouhara

Yuichi Notake

Takuji Shimada

Takayuki Matsuzaki

Takahisa Hagiwara

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.

Disk drive device and head positioning control method

According to one embodiment, a servo writing apparatus that writes a multi-spiral servo pattern to a disk medium is disclosed. The apparatus has a servo controller that generates a servo clock determining a head seek start timing, a servo pattern generator that generates a sector index pulse determining the interval at which a multi-spiral servo pattern is written to the disk medium, a clock phase difference measuring unit that measures a phase difference between the servo clock and the sector index pulse, and a controller that adjusts the measured phase difference.

According to one embodiment, in a disk drive having a disk medium on which servo data is recorded, servo-write management information is recorded on the disk medium, in the form of binary data based on the 0 or 180 degrees out of phase pattern composed of the servo burst signals included in the servo data and being out of phase. The disk drive includes a servo-data reproducing unit that reproduces the servo-data and the servo-write management information.

Method and apparatus for writing servo management information in a disk drive

According to one embodiment, a method of writing a target servo pattern constituting concentric servo tracks on a disk medium provided in a disk drive. In the method, a cumulative amplitude value of the waveform of each spiral servo pattern reproduced by the head of the disk drive is calculated, a slope of each spiral servo pattern is calculated from the cumulative amplitude value, and a pitch at which the head should be moved to write the target servo pattern is determined on the basis of the slopes of the spiral servo patterns.

Growing community of inventors

Tachikawa, Japan

Katsuki Ueda