Hitachi Global Storage Technologies Netherlands B.v.

International Business Machines Corporation

Atsushi Takeichi

Hirofumi Yanase

Manabu Saikawa

Kenji Kuroki

Kenji Ogasawara

Mitsuhiro Shoda

Nobuyuki Kitazaki

Masaomi Ikeda

Kazuhiko Washizu

Michiharu Saitoh

Yuki Hashimoto

Masashi Murayama

A disk drive. The disk drive includes a plurality of head-sliders, an actuator, a plurality of clearance adjustment sections, and a controller. Each head-slider includes a slider and a magnetic-recording head on the slider for accessing a disk for storing data. The plurality of head-sliders is secured to the actuator that is configured to move the plurality of head-sliders concurrently. Each clearance adjustment section corresponds to each head-slider of the plurality of head-sliders and adjusts a clearance of the corresponding head-slider. In addition, the controller is configured to position the actuator by servo control with a first head-slider selected from the plurality of head-sliders, to change a clearance of a second head-slider different from the first head-slider by controlling a clearance adjustment section of the second head-slider to bring the second head-slider into contact with a disk, and to detect the contact to measure the clearance of the second head-slider.

Disk drive, method for measuring clearance and method for writing servo patterns

Embodiments in accordance with the present invention ensure that the pitch of a servo write track is accurately controlled. According to one embodiment of the present invention, a Self Servo Write (SSW) uses different methods and sequences to identify read-write offsets (RWOs) and calculate target positions in inner and outer diameter sides of a magnetic disk. In the inner diameter-side area, the SSW controller uses the readout of a radial pattern written on a recording surface and a reference value to identify the RWO. The SSW controller uses the RWO value identified in the inner diameter-side area to anticipate an RWO value in the outer diameter-side area. In the outer diameter-side area, the SSW controller uses the anticipated RWO value to determine the target position of each servo write track.

Method and apparatus for writing pattern on disk

Disclosed is a data storage device to provide servo patterns of a track pitch individually consistent with head characteristics (writing width, and reading width) in a recording medium of a hard disk device. The data storage device is provided with a disk having pitch information indicating a track pitch recorded in a predetermined area, and a head for scanning the disk to read the TPI ID and reading/writing data from/in the disk by being subjected to seeking control based on the TPI ID. The TPI ID is recorded as a part of a servo pattern in a TPI ID embedded area provided in an outer periphery of a data area of the disk.

Data storage device, recording medium, servo writing method, and data reading/writing method

The invention relates to a method for writing servo patterns on a data recording disk of a disk drive device. A read/write head is stopped at a reference position on the data recording disk, then the read/write head is moved along a radial direction of the data recording disk from the reference position, then a determination is made as to whether the data recording disk has a sufficient width along the radial direction to write a predetermined number of servo tracks, or not, then the servo patterns are written on the servo tracks if the data recording a disk has the sufficient width.

Method and apparatus for writing servo pattern

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Fujisawa, Japan

Atsushi Takeichi