Disk drive employing multiple index marks
AssigneeWestern Digital Technologies, Inc.
InventorSteven R. Vasquez
Life of this patent
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Abstract
A disk drive is disclosed comprising a disk surface having a plurality of concentric, radially spaced tracks, wherein each track comprises a plurality of data sectors and a plurality of servo sectors. At least two different index marks are distributed around the circumference of the disk surface. A servo sector counter is initialized relative to which index mark is detected, wherein the servo sector counter identifies a circumferential location of the servo sectors.
Claims22
A disk drive comprising:
- (a) a disk surface, wherein:
- the disk surface comprises a plurality of concentric, radially spaced tracks;
- each track comprises a plurality of data sectors and a plurality of servo sectors;
- the plurality of servo sectors comprise a first index servo sector, a second index servo sector, and at least one non-index servo sector between the first and second index servo sectors;
- a first index mark identifies the first index servo sector and a second index mark identifies the second index servo sector;
- the first index mark is different than the second index mark;
- (b) a head actuated over the disk surface;
- and
- (c) a disk controller for:
- maintaining a servo sector counter that identifies the circumferential location of the servo sectors;
- detecting one of the first and second index marks;
- and
- initializing the servo sector counter relative to which index mark is detected.
A method of operating disk drive, the disk drive comprises a disk surface having a plurality of concentric, radially spaced tracks, wherein each track comprises a plurality of data sectors and a plurality of servo sectors, the plurality of servo sectors comprise a first index servo sector, a second index servo sector, and at least one non-index servo sector between the first and second index servo sectors, a first index mark identifies the first index servo sector and a second index mark identifies the second index servo sector, and the first index mark is different than the second index mark, the method comprises the steps of:
- (a) maintaining a servo sector counter that identifies the circumferential location of the servo sectors;
- (b) detecting one of the first and second index marks;
- and
- (c) initializing the servo sector counter relative to which index mark is detected.
Dependencies are inferred from the claim text.