Hitachi Global Storage Technologies Netherlands B.v.

Akihiro Sera

Kenji Kuroki

Akira Tokizono

Taichi Nakamura

Kenichi Kuramoto

Nobuhiro Kuwamura

Takao Matsui

Yoshihiko Maeda

Embodiments of the present invention help to detect contact between a head and a magnetic disk more accurately in specifying a heater power value for adjusting a clearance between a head element portion and the disk. According to one embodiment, a hard disk controller/multiprocessing unit (HDC/MPU) measures amplitudes of read signals in a user data field DATA. A hard disk drive (HDD) fills a gap between servo data with single data sector. The HDC/MPU measures the amplitudes of read signals in each data sector at different heater power values. It determines the heater power value at which contact occurs from the measured values.

Device and method for specifying control value for controlling clearance between head and disk, and magnetic disk drive device

A magnetic disk drive includes a magnetic disk and a femto slider. The magnetic disk has a minimum track linear velocity of 1 to 5 m/s. In one embodiment, the magnetic disk drive includes a negative pressure type femto slider and adopts a load/unload method. A gram load 'GL' of a head suspension assembly HSA is set at a value exceeding about 3 mN and smaller than about 15 mN and a pitch static attitude 'PSA' (deg) and pitch stiffness &#x201c;Kp&#x201d; (Nm/deg) satisfy the expression ((PSA&#xd7;Kp)/GL)&#x3c;0.25 mm. As a result, it is possible to prevent the femto slider from assuming a meta-stable flying high state referred to as a bi-stable height. Further, by setting the pitch static attitude &#x201c;PSA&#x201d; at a value of larger than 0 deg, it is possible to prevent the slider from assuming a state of meta-stable contact with the magnetic disk surface referred to as semi-stable drag.

Magnetic disk drive using femto slider and having predetermined linear velocity and gram load configuration

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Kanagawa, Japan

Akihiro Sera