Alps Electric Co., Ltd.

Jun Ide

Tomoo Iizumi

Tooru Kaneko

Hiroshi Yoshida

Yuichi Hishi

Toru Kowaguchi

Yoshitaka Takahashi

A method for restoring the head to the track 0 in a disk drive unit which utilizes a stepping motor to position the head, the method comprising positioning the head to a position outside track 0 by exciting the stepping motor; returning the head thereafter toward an inner side to detect a position where the track 0 is found wihin a cycle of an excitation phase of the stepping motor; positioning the head at a position separated from the outer-most track 0 by a preset number of steps; and then controlling a current ratio to effect an excitation on a preset excitation phase, thereby positioning the head to the position over the track 0.

Method for restoring track 0

A magnetic disk drive device includes a rotatable disk. The disk has at least data tracks and guard band tracks. The data is previously recorded on the data tracks in the reversed magnetization form, whereas no data is recorded on the guard band track. While the magnetic head seeks the data from the tracks, the data is detected at first from the data track. This position where the first data is detected is recognized as a zero track. The magnetic head data seeking is performed based upon this zero track which is electronically detectable.

Method for detecting zero track

A method of re-correcting the position of a head is used in a disk driving device including a zero track restoring arrangement for electrically detecting the zero track position on a magnetic disk, and including a track counter indicating the track position of the magnetic head. The method is configured to monitor the track number of the track counter and never fails to effect re-correction of the position of the head when the track number is '0' or '1'.

Method for recorrecting head position in a disk drive

An information recording disk includes detection regions used to confirm presence or absence of written signals, read/write regions available for signal writing and write-project regions which reject signal writing. Regions where the detection regions and read/write regions overlap each other are originally provided with discriminating signals to distinguish these regions from at least the other regions. The write protect regions are distinguished from the read/write regions, referring to information detected by a head assembly.

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Furukawa, Japan

Jun Ide