Fujitsu Corporation

Tatsuya Gofuku

Eisaku Takahashi

Eiji Okamura

Kazuhide Ohba

Atsushi Satoh

Chihiro Ono

Isao Suda

Takashi Tokairin

Tsutomu Sasaki

Tomoaki Saito

Hirofumi Suzuki

Norihiko Suzuki

Takahiro Ono

Kenji Endo

Hirokazu Ishizaki

Koichi Tohkairin

Masaru Saiki

An actuator driving method and an actuator driving device for PWM-driving an actuator of a storage disk device are disclosed. This method and device prevent a servo signal from being overlapped with switching noises. The storage disk device includes a head for reading information from a storage disk, a PWM driver for generating a drive current having a pulse width corresponding to a current indication value, a linear driver for generating a drive current of which a magnitude corresponds to the current indication value, an actuator, driven by the drive current, for moving the head, and a control circuit for generating the current indication value for positioning the head from the servo information read by the head from the storage disk. The driving method includes a step of PWM-driving the actuator by the PWM driver, and a step of effecting a switchover from the PWM drive to a linear drive by the linear driver during a period for which the control circuit reads the servo information.

Method and apparatus for driving actuator of storage disk device

A disk apparatus has a disk medium with sector areas that have a servo area and a data area along the same cylinder. The servo areas also have a sector mark indicative of the servo area, a code indicative of a cylinder address, and a predetermined servo pattern to detect a head position, all magnetically recorded in the servo area. A disk control section uses a head portion to detect the head position on the basis of a read signal of the servo pattern and positions the head portion at an arbitrary cylinder to perform reading and writing operations. The disk apparatus also has a time measuring counter for starting to measure an elapsed time each time a predetermined position in the servo area is detected, and a time setting register for storing a time from a detection time point of the predetermined position in the servo area to the generation of the sector pulse. A coincidence detecting section is provided to detect that the elapsed time measured by the time measuring counter coincides with the set time of the register, while a pulse generating section is provided for generating the sector pulse when the coincidence is detected by the coincidence detecting section.

Disk apparatus using coincidence detection to generate variable sector

For a balance adjustment due to a reduction in size and weight of an actuator, an arm portion, an axis attaching portion, and a coil supporting portion are arranged so that the centers of gravity on the coil side are located on a straight line connecting a rotational center and the center of gravity on the head side. Further, the improvement of an assembling efficiency of a VCM, an increase in torque, a one-touch fixing of an FPC connecting band, a noise prevention of a read pattern, and an insulation between the base and cover due to a bias of an MR read head are accomplished. A sector mark is detected by comparing a peak detection pulse and its reference polarity signal. A redundancy is provided to a reference detection polarity signal so that a read signal can be detected even if any one of the read signals of the sector marks is dropped out. A gray code detecting section for recognizing a cylinder address also detects on the basis of a peak detection pulse and a polarity signal due to the reading of a gray code. A memory space to store a program is divided into an ROM space of a small electric power consumption and an RAM space of a large electric power consumption and stores each peculiar program.

Head positioning control for disk apparatus using peak detection,

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Kawasaki, Japan

Tatsuya Gofuku