US 12,518,784 B1 · Magnetic disk device and method for manufacturing magnetic disk device

Abstract

A magnetic disk device according to an embodiment includes: a magnetic disk including a plurality of tracks; a magnetic head that performs data reading and data writing on the magnetic disk; a plurality of servo regions that is provided in each of the plurality of tracks, and at least partially includes a first physical pattern, the first physical pattern being a physical pattern after writing of a first data pattern including position information of each of the plurality of tracks; and a controller that controls the magnetic head, wherein the plurality of servo regions includes one of a first servo region including the first physical pattern, and a second servo region including a second physical pattern, the second physical pattern being a physical pattern after writing of a second data pattern different from the first data pattern, for each of the plurality of tracks, and the controller performs determination as to which of the first and second physical patterns a third servo region has, the third servo region being one of a servo region among the plurality of servo regions included in the plurality of tracks.

Claims16

Dependent claims

A magnetic disk device comprising:

a magnetic disk including a plurality of tracks;
a magnetic head that performs data reading and data writing on the magnetic disk;
a plurality of servo regions that is provided in each of the plurality of tracks, and at least partially includes a first physical pattern, the first physical pattern being a physical pattern after writing of a first data pattern including position information of each of the plurality of tracks;
and
a controller that controls the magnetic head, wherein
the plurality of servo regions includes one of
a first servo region including the first physical pattern, and
a second servo region including a second physical pattern, the second physical pattern being a physical pattern after writing of a second data pattern different from the first data pattern, for each of the plurality of tracks, and
the controller performs determination as to which of the first and second physical patterns a third servo region has, the third servo region being one of a servo region among the plurality of servo regions included in the plurality of tracks.

6 more elements

A method for manufacturing a magnetic disk device, the method comprising:

in a plurality of servo regions used to write a first data pattern including position information of each of a plurality of tracks included in a magnetic disk, writing a second data pattern different from the first data pattern, the plurality of servo regions being provided in each of the plurality of tracks and to have a first physical pattern after writing of the first data pattern, the first physical pattern being a physical pattern after writing of the first data pattern;
overwriting the first data pattern on at least some of the plurality of servo regions including a second physical pattern that is a physical pattern after writing of the second data pattern;
acquiring a first read waveform obtained by reading the first physical pattern overwritten on the second physical pattern and a second read waveform obtained by reading the second physical pattern;
and
based on the first and second read waveforms, setting a threshold used to determine which of the first and second physical patterns a predetermined servo region has, the predetermined servo region being one of a servo region among the plurality of servo regions included in the plurality of tracks.

2 more elements

Dependencies are inferred from the claim text.

Magnetic disk device and method for manufacturing magnetic disk device

Life of this patent

Magnetic disk device and method for manufacturing magnetic disk device

Life of this patent

Abstract

Claims16