Hitachi, Ltd.

Shinobu Yoshida

Shozo Saegusa

Tsuyoshi Takahashi

Hiroshi Nishida

Toshihiro Arisaka

Toshihiko Shimizu

Kenji Mori

Yoshiaki Yamauchi

Katsutoshi Nii

Keiko Watanabe

Tetsuya Hamaguchi

Kihachiro Tanaka

Takashi Kouno

Masaru Muranishi

Kenji Tomida

Kazuhiko Kawakami

Yuuichi Yanagase

Hisahiro Miki

Takashi Matsuki

Mitsuyuki Tsuyuki

Hiroshi Ikeda

Shigeki Mori

Yuzo Yamaguchi

Yokuo Saitoh

Takuji Torii

Yasuhiro Matsuda

Hideyuki Kimura

Kuniyuki Kimura

Yoshihiro Sato

Takashi Ishikawa

Noriyuki Kumasaka

Hiroyuki Tanaka

Takeshi Harada

Takashi Yoshida

Masataka Kawauchi

Isao Shimizu

Ikuo Nishida

Kyuichiro Nagai

Kazutaka Sato

Masahiko Sega

Akira Mochizuki

Marutomo Goto

Toshio Matsushita

Jyunichi Matsuno

Tomoki Hirata

Yoshihiro Satou

Taro Sonoda

Kenichiro Takezawa

Hisanobu Tajima

Yoshiko Kawabe

A spindle motor for magnetic disc device includes a hub having an inside and an outer peripheral side on which a magnetic disc is mounted, a rotary shaft having an axial direction and coupled with the hub so as to be integrally rotated therewith, with the motor being arranged on the inside of the hub. The hub, the rotary shaft and a part of the motor constitute a rotary body. A radial bearing having a length in the axial direction of the rotary shaft, for supporting the rotary body in a direction crossing the rotary shaft, and a thrust bearing for supporting the rotary body in the axial direction of the rotary shaft are provided. The thrust bearing has an outer diameter greater than the length of the radial bearing, and is arranged at a position which is inside of the motor and diametrically inward of the hub.

Spindle motor and magnetic disc device using thereof having radial and thrust bearings

A spindle motor used in a magnetic disc apparatus having a hub to which a magnetic disc is mounted and a rotary shaft to which the hub is fixed. The rotary shaft is located in a bearing casing having one end opened and the other end closed by a hydrodynamic pressure radial bearing, the rotary shaft being supported by a hydrodynamic pressure thrust bearing and the hydrodynamic pressure radial bearing. An inner diameter D and a width L of the hydrodynamic pressure radial bearing having a relationship of L/D<1.

Spindle motor and magnetic disc device with hydrodynamic bearings

Disk storage devices have exhibited an increase in rotational vibrations which attend high speed rotation due to weight unbalance of a disk. Accordingly, an unbalance correcting mechanism, provided with correcting balls to correct the aforesaid unbalance, meets a problem that the correcting balls are made unstable at the time of low speed rotation to generate vibrations and noises. A disk drive device is provided with an unbalance correcting mechanism comprising an annular-shaped groove provided in a turntable on a spindle motor and a plurality of correcting balls received in the groove, and in which a sliding resistance member is provided on a bottom surface of the annular-shaped groove to suppress a sliding resistance of the correcting balls on the sliding resistance member, and a correcting ball motion auxiliary member is provided on an inner peripheral side wall of the groove (toward an axis of rotation).

Disk drive device

A rotary shaft is rotatably supported by a hydrodynamic fluid radial bearing and a hydrodynamic fluid thrust bearing which are excellent in shock resistance, an bearing arrangement in which vibration in a translation mode of the shaft, among vibration components caused by unbalance force exerted to the rotary shaft, is supported by the radial bearing, and vibration in conical mode is supported by the thrust bearing, magnetic fluid is used as lubrication oil, and a permanent magnet is located between the radial bearing and the thrust bearing so as to apply a magnetic attracting force between the rotary shaft and the thrust bearing so as to carry out axial positioning in order to use the magnetic disc device in an arbitrary attaching posture. With this arrangement, the magnetic disc device using such a bearing arrangement can enhance portability, thinning and antishock ability, and reduce noise and power consumption, thereby it is possible to provide a note-type personal computer with a high degree of reliability.

Spindle motor and magnetic disc device with hydrodynamic bearing

In magnetic disk structures having a high density, positioning errors (generally referred to as &ldquo;flutter error&rdquo;) occur due to a fluctuation of a magnetic disk. As a result, reading precision deteriorates. This is a significant problem in realizing a large capacity for a magnetic disk apparatus. This can be resolved by providing a magnetic apparatus such that a suspension which holds a slider having a magnetic head at one end and which is attached to a supporting arm at the other end is inclined so that an interval between the suspension and the magnetic disk is small on the inner rim side and is large on the outer rim side with this arrangement, the occurrence of the positioning error due to the fluctuation of a deformation of the magnetic disk is reduced, thereby enabling a high density recording of the magnetic disk.

Magnetic disk apparatus

The number of revolutions of a disk is once increased to a higher level than a resonance frequency of a rotation support system at the startup of rotation of the disk, and subsequently servo control for a pickup actuator is made to work to read information from the disk. It is possible to increase reproducibility of the disk unbalance correction and improve the apparatus in reliability without generation of vibrations and noises, and to spin the disk at high speed.

Disk type reproducing apparatus and revolution control method

A magnetic head slider having a recording-reproducing element for recording and reproducing information relative to a magnetic recording medium. A sliding protective film is formed at one outer side or each of opposite outer sides of that portion, constituting the recording-reproducing element, in a direction perpendicular to a travel surface of the magnetic head slider opposed to the magnetic recording medium, at least part of the sliding protective film covers that portion reaching the travel surface, and the sliding protective film is also formed on each of side surfaces of the slider.

Magnetic slider head and method of producing the same

The present invention provides a disk apparatus and a motor therefor that require low power consumption and reduce errors during recording or reproduction by damping vibration, preventing the motor from falling toward a head. In a disk apparatus comprising a motor and a head, the motor has a rotating portion and a fixed portion, the rotating portion of the motor has a device for holding a disk, the fixed portion of the motor has a bearing section and a stator section mounted in the disk apparatus via damping members, and the damping members are provided in such a way that one side of these members which is closer to a line joining the motor with the head has a higher rigidity than the other side.

Disk apparatus and motor therefor

A disc device which includes a rotary drive mechanism for rotating a replaceable recording medium. An unbalance correcting mechanism adapted to correct unbalance is incorporated in a rotary body rotating unit in the rotary drive mechanism, and includes a holding system having a holding member for holding the rotary drive mechanism and a head having at least a reproducing function. Further included is a support member composed of resilient members, for supporting a casing and a unit holder to each other. The holding system has a natural frequency higher than 30 Hz but lower than 70 Hz, and exhibits a transmission characteristic having a lift-up degree of higher than 8 dB at a resonant point.

Disc device having disc in balance correcting arrangements

Magnetic head slider and method of production thereof

Bearing assembly having compact thickness, spindle motor and actuator

Magnetic disk unit having anti-impact arrangement

A rotating disk type information storage apparatus includes a rotating disk for storing information, a head for writing/reading the information, a support member for supporting the head, a first actuator for moving the support member to a predetermined position on the rotating disk, and a second actuator including a movable member supported by the support member and capable of being rotated about an axis perpendicular to a recording surface of the rotating disk, and a driving force generating member for rotating the movable member. The movable member is integrated with the support member and has the head mounted thereto, in which a center of gravity of the movable member including the mounted members generally coincides with the center of rotation of the movable member. The second actuator corrects an error in a positioning of the support member and positions the head, and the movable member is not vibrated during the positioning.

Rotating disk type information storage apparatus having a movable member

In magnetic disk structure having a high density, positioning errors (generally referred to as 'flutter error') occur due to fluctuation (i.e., flutter) of a magnetic disk. As a result reading precision deteriorates. This is a significant problem in realizing a large capacity providing magnetic disk apparatus. This can be resolved by magnetic apparatus such that a suspension which holds a slider having a magnetic head at one end and which is attached to a supporting arm at the other end is inclined so that an interval between the suspension and the magnetic disk is small on the inner rim side and is large on the outer rim side with this arrangement the occurrence of the positioning error due to the fluctuation of a deformation of the magnetic disk is reduced, thereby enabling a high density recording of the magnetic disk.

A disk locating actuator of a disk apparatus has a carrier member carrying a head and a curved flexible printed circuit fixed at its one end to the carrier member and at its other end to a base. Angles at which the flexible printed circuit is fixed are suitably determined so as to diminish any dynamic reacting force produced by vibration of the flexible printed circuit, thus ensuring high degree of head locating precision.

Head locating actuator having reduced susceptibility to dynamic reaction

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Tsuchiura, Japan

Shinobu Yoshida