Hitachi, Ltd.

Hitachi Global Storage Technologies Netherlands B.v.

Masami Miyatake

Shigeo Nakamura

Mikio Tokuyama

Yoshinori Takeuchi

Kenji Mori

Masao Iwakura

Satomitsu Imai

Jyousei Shimizu

Tetsuo Masukawa

Sunao Yonekawa

Susumu Ebihara

Nobuyuki Okamoto

Hiroaki Shigenaga

Noriki Une

Yasuhiro Yaginuma

Embodiments of the invention provide a magnetic disk unit in which there has been adopted a structure fixing a base and a top plate and preventing a deformation by a bimetal effect. In one embodiment, the magnetic disk unit includes a magnetic disk; a head drive mechanism in which is mounted a head accessing the magnetic disk; a base accommodating the magnetic disk and the head drive mechanism, and possessing a flat part, in which a threaded hole has been formed, in a circumference of an opening edge; and a top cover which is formed by a material whose thermal expansion coefficient differs from that of the base, in which there is provided an escape hole, for a screw, position-aligned to the threaded hole of the flat part, and which is attached to the base by the screw penetrating through the threaded hole and the escape hole for the screw. A slip mechanism for reducing a slip friction resistance is provided respectively in a contact portion between the flat part and the top cover, and a contact portion between a head part of the screw and the top cover.

Structure to prevent deformation of magnetic disk device housing

Gain information in a read amplifier, which is recorded when data to be measured is reproduced, is stored in an AGC control memory circuit in advance. By reproducing the data using the gain information, reproduced data varied according to the amount of flotation of a magnetic head and the position of the magnetic head alone can be obtained. A variation in voltage amplitude of the reproduced data is detected by an envelope signal generating circuit and a variation in phase difference between a reading cycle in which the reproduced data is read and a reference cycle is detected by a phase difference signal generating circuit. A calculator calculates a float interval of the magnetic head and a variation in the position thereof based on these detected variations. As a result, a decision can be made as to whether the float interval of the magnetic head and the variation in the position thereof exceed an allowable range. When it is judged that they have exceeded the allowable range, a warning is issued to a user so that the magnetic head and a magnetic disk can be prevented from breakage in advance.

Magnetic disk device for detecting a floating state of a magnetic head

A structure for supporting a magnetic head slider for a linear magnetic disk unit comprises: a magnetic head slider having air bearing rails located opposite to a magnetic disk so as to extend in a direction of a track of the magnetic disk; a gimbal for elastically supporting the magnetic head slider, the gimbal being bonded to a back surface of the magnetic head slider on a side reverse to the air bearing rail; and a support arm having the gimbal secured to its distal end, whose axis extends in a direction perpendicular to the air bearing rail, which support arm gives the magnetic head slider a pressing force toward the magnetic disk. The gimbal includes: a substantially rectangular joining portion to be bonded to the back surface of the magnetic head slider, the joining portion having longer sides extending in a direction perpendicular to the axis of the support arm and shorter sides extending in the axial direction of the support arm; a bridging portion to be bonded to the back face of the magnetic head slider, the bridging portion extending from a middle portion of the lower side of the joining portion on the opposite side to the support arm outwardly in the axial direction of the support arm; flexible portions extending from the bridging portion so as to surround the bridging portion and the joining portion; and a support portion extending from the flexible portions on the opposite side to the bridging portion rearward in the axial direction of the support arm.

Structure for supporting a slider with magnetic head for a linear

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Kanagawa, Japan

Masami Miyatake