Fujitsu Corporation

Toshiba Storage Device Corporation

Nhk Spring Co., Ltd.

Aruga Research LLC

Keiji Aruga

Yoshifumi Mizoshita

Tomoyoshi Yamada

Shinji Koganezawa

Takao Sugawara

Hiroyuki Iwahara

Yasumasa Kuroba

Tomoo Sukagawa

Hiroyuki Mase

Masaru Matsumoto

Toru Kouhei

Takahiro Imamura

Mitsuhiro Izumi

Masao Tsunekewa

Shuichi Hashimoto

Tatsuro Sasamoto

Hiroshi Maeda

Susumu Hasegawa

Mitsuaki Yoshida

Kenichiro Aoki

Masaya Suwa

Yukihiro Uematsu

Akihide Jinzenji

Yasuhiro Miura

Toshiyuki Nakada

Yoshiaki Koizumi

Takuma Kido

Yasuyoshi Asao

Kazuhiro Suzuki

Keiji Watanabe

Nobuyuki Suzuki

Kazuhiko Takaishi

Susumu Yoshida

Masao Hanya

Toru Watanabe

Isamu Tomita

Masaharu Sugimoto

Tsuneyori Ino

Makoto Sakairi

Hiroshi Chiba

Yoshiharu Matsuda

Yoshinori Ogawa

Kazunori Tochiyama

Yoshiaki Nagasawa

Takenori Ohshima

Toru Kohei

Shinji Fujimoto

Kei Funabashi

Toshifumi Hatagami

Masahito Iwatsubo

Yasuhiro Hamada

Umeo Oshio

Koichi Aikawa

Masao Tsunekawa

Keishi Shimizu

Norihiko Suzuki

Takahisa Ueno

Toshinori Hoshino

Takeshi Ohyama

Terushige Arai

Hiroshi Nagata

Nobuyoshi Nakayama

Shigeyuki Kotake

Nobuyuki Hirono

According to one embodiment, a magnetic disc apparatus includes a magnetic head which reads information stored in a magnetic disc, an arm which supports the magnetic head, and a feedback controller which controls a coarse actuator to move the magnetic head above the magnetic disc by driving the arm, a fine actuator to hold a position of the magnetic head, and a feedback path which feeds back a displacement of the actuator to a target value of the coarse actuator. The feedback controller controls decoupling of a double actuator system which adds up the coarse actuator and the fine actuator.

Double servo type magnetic disc apparatus

An apparatus that corrects a weight imbalance around an axis of a spindle motor that rotates a disc in a disc drive includes an impact applicator that applies an impact to a housing that houses the spindle motor and the disc, a plate that supports the housing and impact applicator, a spring member that supports the plate, and enables the plate and the housing to vibrate together when the spindle motor rotates, and a detector that detects a vibration of the housing when the spindle motor rotates.

Balance corrector

The present invention relates to a magnetic head actuator and a magnetic disk device in which a magnetic head is moved to a predetermined position by actuating an arm on a revolving magnetic disk. A magnetic head actuator comprises an arm in which a suspension for supporting a magnetic head is provided, the arm being actuated to move the magnetic head. A damper material is provided on at least one side of the arm, the damper material comprising a restriction material and a viscoelastic material, the restriction material suppressing vibrations of the arm, and the viscoelastic material absorbing vibrations of the arm.

Magnetic head actuator and magnetic disk device having damper material attached to actuator arm

A first component defines a threaded bore. A second component is kept in contact with the first component. A clamping screw penetrates through the second component and is screwed in the threaded bore. A lubricating agent film is interposed between the threaded bore and the clamping screw. The lubricating agent film is made of a macromolecular compound having a polar end group. The lubricating agent film serves to reduce the friction between the threaded bore and the clamping screw. Generation of dust is prevented when the clamping screw is being screwed into the threaded bore. In addition, the clamping screw exhibits a larger axial force at a certain amount of a fastening torque as compared with a conventional clamping screw. A larger axial force can thus be applied to hold the second component onto the first component.

Product including filmed screw

A method for manufacturing a head stack assembly that includes a pair of suspensions each of which supports a head, an arm that drives the head, and a pair of base plates that attach the pair of suspensions to both sides of the arm that has a perforation hole, each of the pair of base plates having a boss with an opening includes the step of swaging the pair of base plates with the arm by passing, in one direction, a processing member larger than the opening through the perforation hole and the base plates while the pair of base plates are being inserted into the perforation hole at both sides of the perforation hole, wherein where a neutral plane is defined as a plane that halves a thickness of the arm and is perpendicular to a section that includes a center axis of the perforation hole, a first position is defined as a position that has a minimum internal diameter of the base plate, and a second position is defined as a position closest to the neutral plane among contact positions between the base plates and the arm, a distance between the neutral plane and the first position is equal to or smaller than a distance between the neutral plane and the second position before the swaging step.

Head stack assembly, its manufacturing method, and magnetic disc drive having the same

A magnetic disc apparatus has a ramp holding the magnetic head in a position apart from the magnetic disc and a filter case holding a filter in the state of being bent in such a manner that the filter surrounds the ramp together with the magnetic disc. The filter removes dust in airflow which flows in the magnetic disc apparatus accompanying the rotation of the magnetic disc.

Filtering device for a magnetic disc apparatus

A plate member is made of a metal material lighter than stainless steel in a suspension for a head slider. This leads to a reduction in the weight of the suspension. The natural frequency of the suspension is thus raised. Moreover, the viscoelastic member is interposed between the front surface of the plate member and the back surface of the flexure. This structure allows either the plate member or the flexure to act as a base and the other to act as a constraining member. In other words, the plate member, the flexure and the viscoelastic member in combination act as a so-called vibration damper including constraining layers. The viscoelastic member serves to further suppress vibration of the plate member and the flexure.

Head suspension including flexure having as elastic bending section

A magnetic head structure has a coil and a magnetic pole allowing a magnetic flux generated by the coil to be transmitted therethrough and forming a magnetic gap. An insulating layer surrounds the coil, and a protective layer covers the insulating layer and the magnetic pole. The insulating layer has a volume equal to or greater than a value which is determined with respect to a thickness of the protective layer. It is preferable to increase the volume of the insulating layer as the thickness of the protective layer is made greater. By increasing the volume of the insulating layer, the protrusion of a portion of a floating surface of the magnetic head slider near the magnetic pole, toward the disk, is reduced.

Magnetic head structure with insulating layer configured to reduce thermal deformation of floating surface towards disk

Vibrations in a magnetic head assembly equipped with a magnetic head, caused by the effects of the flow of air arising from the high-speed rotation of a magnetic disk, can be suppressed by affixing a damping material to the magnetic head assembly. As a result, accurate positioning is possible with high reliability, the frequency of occurrence of errors during data recording and playback can be suppressed, high data transfer rates can be maintained, and high recording densities for a magnetic disk device can be realized.

Magnetic head assembly

A magnetic disk unit has two actuators each rotating on a common rotary shaft. The two actuators are driven by a voice coil motor. The voice coil motor comprises: a magnetic circuit comprising a magnet provided for the two actuators on a common basis and two yokes, which are associated with the two actuators, respectively, said two yokes being disposed at both sides between which the magnet intervenes; and two coils provided for the two actuators, respectively.

Storage device

A cover seal seals an opening of a housing body and encloses a cover for the opening in cooperation with the housing body. The rigidity of the cover seal is reinforced by a metallic sheet or a multiplayer synthetic resin sheet, so that vibration of the cover seal is prevented even if an air stream is a seam between the housing body cover acts on the cover seal from behind.

Sound reducing cover seal for information recording apparatus

A small-sized rotational vibration testing apparatus having a wide band of measuring frequencies and capable of directly driving a rotary table ( ) to oscillate or vibrate in a rotational direction under the action of torque generated by a vibration applying mechanism. The rotary table ( ) is rotatably mounted on a base ( ), and a plurality of coil frames ( ) each having a coil ( ) attached thereto are mounted on a flange ( ) of the rotary table ( ) at an equal circumferential pitch or interval about its axis of rotation. A plurality of magnetic circuits ( ) are fixedly secured to the base ( ) in such a manner that the center of each coil ( ) is positioned at the center of an associated magnetic circuit ( ).

Rotational vibration testing apparatus

A detection circuit in a magnetic recording and playback apparatus which uses partial response and the maximum likelihood method, in which neither the size of the detection circuit nor the power consumption increase when the partial response order n increases. In this detection circuit, in the circuit that detects a signal read out from a head, either a plurality of equalizers for different target equalization waveforms, or a single variable target equalizer is provided. A detector for the waveform output from an equalizer is connected in series with the detector. A plurality of combinations, each formed by an equalizer and a detector, is connected in parallel to the output of a filter, the outputs of the combinations of equalizers and detectors being input to a switching circuit, which is controlled by a switching control means. The switching control means controls the switching circuit so that just one of the combinations of equalizer and detectors is selected as the detector output. If a variable target equalizer, which is capable of generating two or more different types of equalization waveforms, is used as the equalizer, it is possible to reduce the number of equalizers to one.

Detecting circuit for read signal from magnetic recording system using partial response

A recording disk drive includes a shroud wall spaced from a peripheral end of the recording disk by a gap equal to or smaller than 0.5 mm. A rectification groove is formed in the shroud wall at a position adjacent an area opposed to the peripheral end of the recording disk. Reduction in gap between the peripheral end of the recording disk and the shroud wall serves to reduce the amplitude of the flutter to be induced in the rotating recording disk. Moreover, as the gap gets smaller, the flutter reduces at a higher rate in response to increase of the depth of the rectification groove. Specifically, if the gap between the peripheral end of the recording disk and the shroud wall is set equal to or smaller than 0.5 mm, the groove can be made shallower so as to still efficiently suppress the flutter of the rotating recording disk.

Recording disk drive and method of assembling the same

Disclosed herein is a magnetic disk drive including a spindle shaft fixed to a base, a coil mounted on the spindle shaft, a spindle hub rotatably mounted on the spindle shaft, a magnetic disk fixed to the spindle hub and having a plurality of tracks, a permanent magnet fixed to the spindle hub, a magnetic head for reading/writing information from/to the magnetic disk, and an actuator for moving the magnetic head across the tracks of the magnetic disk. The magnetic disk drive further includes a cover fixed to the base and having a hole at a position corresponding to the spindle shaft, a first metal washer placed on the cover at a portion around the hole, a second metal washer for sandwiching the cover at the portion around the hole in cooperation with the first metal washer, and a screw for securing the first and second metal washers to the spindle shaft.

Magnetic disk drive capable of reducing noise at starting utilizing conjoining, damped washers to support shafts in the disk drive

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Kawasaki, Japan

Keiji Aruga