Fujitsu Corporation

Kazuo Nishimura

Tatsuro Sasamoto

Hideaki Tanaka

Hiroaki Etoh

There is used a disk medium in which tracks are divided into a plurality of zones in the radial direction and information is read and written with a constant linear density by using a clock signal of a different frequency every zone. A drive unit forms a dead space corresponding to at least one track at a zone boundary of the disk medium and reads or writes the information. In the case where it is judged that the head passes through the zone boundary by the seeking operation to the cylinder address position instructed from an upper apparatus, the cylinder address instructed from the upper apparatus is corrected on the basis of the number of boundary passing times and the seeking operation is performed.

Magnetic disk apparatus, recording and accessing method for performing

Magnetic disk apparatus, recording medium, and accessing method for

A method of controlling start-up of a sensorless spindle motor used in a disk apparatus reduces time spent on start-up of a spindle motor with high reliability. The motor is used for rotating a disk on which information is recorded, and no sensor is provided in the motor for sensing an angular position of a rotor relative to a stator of the motor. The motor is operated at a steady rotational speed and is stopped by supplying a stop command. An aligning operation is performed immediately after the motor is stopped. The aligning operation is performed to rotate the rotor to a predetermined angular position relative to the stator of said motor. The motor is operated at a steady speed by a synchronization control when operation of the motor is started by supplying a start command.

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Kawasaki, Japan

Kazuo Nishimura