Hitachi, Ltd.

Takashi Kohno

Takashi Yoshida

Kenji Mori

Hideaki Amano

Kenji Tomida

Osami Matsushita

Takao Terayama

Isao Shimizu

Yuzo Yamaguchi

Katsuaki Kikuchi

Hiromu Hirai

Tomoaki Inoue

Michiaki Ida

Yasuhiro Matsuda

Takeshi Yoshida

Osamu Beppu

Masaaki Nakano

Akio Takatsuka

Taro Sonoda

Mashanori Kohchi

Kouji Satoh

Hiroyuki Ono

Hideo Tomizawa

A disc device includes a housing, a fixed shaft at least partially disposed in the housing, wherein the fixed shaft is divided into two parts which are joined together. The disc device also includes one or more discs, a hub for loading the discs, at least a head for reproducing information recorded on each of the discs, and a drive system for moving the head to any position on each of the discs. A motor for driving the hub to rotate is provided outside the housing, and at least two fluid film bearings are provided so that the hub is supported by the fixed shaft so as to be rotatable.

Disc device

When a disc device employs a fluid bearing, vibrations can be decreased at a high-speed rotation. There are, however, problems of deterioration in bearing rigidity and leakage of lubricating fluid with increase in temperature. For this reason, a motor is disposed outside a housing, two shafts which differ in diameter from each other are joined with each other to form a fixed shaft, each of the two shafts is provided with a fluid bearing, a magnetic fluid is used as a lubricating fluid, and a magnetic seal is provided outside each bearing.

A miniature magnetic disk device or a miniature optical disk device has a recording disk having a diameter less than or equal to 0.7 inches. The disk device also includes a spindle motor which rotates the recording disk, a read/write head for recording or reproducing information on and from the recording disk, a support member which holds the read/write head, and a support shaft which is coupled to the support member. A voice coil motor, which is coupled to the support member and the support shaft, sets the read/write head in a desired position over the disk. A resistor which has a value of at least 2.5.OMEGA. is connected in series with a coil of the voice coil motor, and the resistor makes it possible to reduce power consumption of the voice coil motor. The resistor may be a variable resistor, and a conductor of the coil may have a cross-sectional area less than 2.55.times.10.sup.-3 mm.sup.2. A ratio h/t of a thickness h of the coil to a thickness t of a magnetic circuit of the voice coil motor have be at least 0.25. Moreover, by mounting several of these disks on a board which is standardized as PCMCIA type 3, a miniature array disk device is formed.

Miniature magnetic disk device and voice coil actuator thereof

A rotary information recording/reproducing apparatus has a carriage rotatable by the first and second driving coils about an axis that moves an information recording/reproducing head radially to an associated recording disk for head positioning relative to the disk. The angle between a line connecting the center of the first driving coil and the center of the carriage pivot shaft and a line connecting the head and the center of the carriage pivot shaft is set to be not greater than 90 degrees while the angle formed between the first and second driving coils about the center of the carriage pivot shaft is within the range of from 100 degrees to 150 degrees, whereby reduction in the size and thickness of the apparatus can be achieved. A magnet-yoke assembly, which is subject to a reaction force, is mounted to a base by sheet springs and reaction-force damping members interposed therebetween so that the magnet-yoke assembly is independent from and infinitesimally rotatable relative to the base. The provision of the two driving coils and the reaction-force damping members effectively prevents the carriage pivot system and the disk spindle from being excited by the reaction force to thereby assure a high-speed and highly-accurate head positioning.

Rotary information recording/reproducing apparatus carriage actuator

A rotor magnet is attached to the inner peripheral portion of a hub to attach a magnetic disk or the like and a stator is provided in the outer peripheral portion of a bearing housing so as to face the rotor magnet, thereby forming a rotating mechanism. A magnetic pre-load mechanism is provided and a spindle is pressed to one side of a radial bearing, thereby stabilizing the rotation.

Spindle unit having pre-load mechanism

A rotary magnetic head apparatus for use in a VTR and producing a low level of vibration by restraining the unbalance of an overall rotary body of the magnetic head apparatus. The apparatus includes a fixed cylinder for supporting a rotary shaft via bearings, a rotary cylinder secured to one end of the rotary shaft and having magnetic heads, and a motor rotor directly coupled with the other end of the rotary shaft. At least one first balancer and at least one second balancer are respectively provided in the rotary cylinder and the rotor so as to compensate for the unbalance of the rotary body composed of the rotary cylinder, the rotary shaft, and the rotor.

Mechanism for balancing a rotary magnetic head apparatus

This invention relates to a magnetic disk apparatus equipped with magnetic bearings for supporting a spindle without contact by a magnetic attracting or repulsing force. The magnetic disk apparatus prevents occurrence of oscillation of magnetic disks and accomplishes high accuracy positioning.

Magnetic disk apparatus

Growing community of inventors

Ibaraki, Japan

Takashi Kohno