Hitachi, Ltd.

Mikio Takahashi

Yoshihiro Moribe

Osamu Beppu

Kazuo Nakagoshi

Nobukuni Ohkubo

Yasuo Yamamoto

Shigeo Nakamura

Hiroshi Sakurai

Hiroshi Daito

Toshio Suzuki

Kiyotake Kumazawa

Akira Chuma

Hideo Maekawa

Eiji Nakanishi

Masahiro Mitamura

Kiyoji Morita

Noriaki Minamide

Takaaki Abo

Masato Furusaki

A magnetic disk apparatus has a disk assembly including a single servo disk and a plurality of data disks, a servo-head supporting structure for supporting a servo head and data-head supporting structures for supporting data heads. These heads are so disposed as to cooperate with respective disks. The servo-head and data-head supporting structures are driven by an actuator to move the servo head and the data heads to the required positions on the corresponding disks. The servo-head supporting structure and each of the data-head supporting structures have different proper oscillations to prevent the occurrence of a resonance during a seek operation.

Magnetic disk apparatus with head supporting structures of different

A disk drive housing structure has a rotating disk for recording information and a transducer adapted to write and read information on and from the disk. The structure further includes a positioning system having at least an arm to which the transducer is fixed and which is adapted to selectively position the transducer along the radial direction of the disk transducer by turning the arm. The structure also includes a member on which the disk, transducer and positioning system are mounted, wherein the mounting member includes a first housing which supports thereon both ends of a rotary shaft of the recording medium and both ends of a rotary shaft of the positioning system, and which has a first aperture part. The first housing further includes a second aperture part through which the disk and the rotary shaft supporting the disk are inserted and to which a supporting member for the rotary shaft of the recording medium is fixed.

Disk drive housing structure

A method of adjusting the position of a magnetic head in a magnetic head positioning mechanism positions the magnetic head at a target track on a magnetic disk. Since a floppy disk system is so designed as to make a floppy disk replaceable, it is necessary to adjust accurately the position of the magnetic head from the position of a spindle. According to the present invention, the position of the magnetic head is adjusted by the method wherein the displacement of an amount of deviation from a prescribed track in the magnetic head positioning mechanism is calculated beforehand, the amount of deviation is sampled subsequently by moving the magnetic head, this sampled amount of deviation is compared with the aforesaid calculated displacement to know the maximum and minimum values of the amounts of deviation on the track of movement of the magnetic head, and the adjustment is implemented on the basis of these values.

Method for adjustably positioning a transducer for a disc drive

A method and apparatus for moving a moving member of a positioning mechanism to a target position by means of a stepper motor as a driver. The method and apparatus alleviate the positioning error attributable to the hysteresis of the stepper motor, which is inherent in stepper motor drive systems, by controlling the oscillation damping condition when the stepper motor has entered a damped oscillation phase in the vicinity to the target positon. The damping condition is controlled by varying the solid friction factor of the mechanism or the drawback torque constant of the stepper motor.

Positioning method and apparatus therefor

In a disk unit having a rotating mechanism to rotate the disk by pinching the disk at both sides, and a loading mechanism to bring a read-write head into contact with the disk, a method for driving the disk includes the steps in which, at the time of recording and reproduction, the rotating mechanism and the loading mechanism are actuated simultaneously, and when the recording and reproduction are completed, the rotating mechanism is stopped simultaneously with release of the loading mechanism, or after the lapse of a predetermined time from the release.

Method and apparatus for driving a disk

A magnetic disc head positioning system using a stepper motor eliminates positioning errors due to different approach directions and distances to a target track position through a drive control of temporarily stopping the head at a position immediately preceding or following the target track depending on the approach direction and, thereafter, moving the head from this position to the target track with a constant transient response. The head is brought to the temporary stop position by utilizing the overshooting response of the stepper motor so as to minimize the positioning time.

Control method and apparatus for positioning servo system

A floppy disk driver intended to protect the disk center hole from damage when the disk is mounted. The arrangement includes a speed detection circuit for detecting a relatively low rotational speed of the disk and a control circuit for speeding up the disk to a higher rotational speed for the read/write operation in response to the detection of the lower disk speed, whereby the disk is protected from damage by being rotated at the lower speed when its center hole is held between the collet and spindle.

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Odawara, Japan

Mikio Takahashi