Method and system for time-shift based rotational vibration sensing in disk drives
View Patent ↗A method (and structure) senses a rotational vibration of a disk drive. The disk drive includes a rotating disk. The disk includes a plurality of reference bits across a surface thereof. The method (and structure) includes detecting the reference bits across a pattern on the rotating disk, and analyzing a time interval between adjacent ones of the reference bits.
1. A disk sector structure, comprising:
a block representing an average time between detection of adjacent ones of reference bits spread across a disk;
a preamble;
a servo address mark block adjacent said preamble;
a track block adjacent said servo address mark block;
a sector number adjacent said track block;
a position error signal burst block adjacent said average time block; and
a data block adjacent said position error signal burst block.
2. An article, comprising:
a disk;
a disk sector structure, comprising:
an average time block representing an average time between detection of adjacent ones of reference bits spread across the disk,
wherein the average time is measured in a quiescent mode of a disk drive containing the disk.
3. The article according to claim 2 , wherein the disk sector structure further comprises:
a preamble;
a servo address mark block adjacent said preamble;
a track block adjacent said servo address mark block;
a sector number adjacent said track block;
a position error signal burst block adjacent said average time block; and
a data block adjacent said position error signal burst block.
4. A disk drive, comprising:
a disk;
a head unit configured to read from and write to the disk;
a servo operable to actuate the head unit relative to the disk; and
a disk sector structure, comprising:
an average time block representing an average time between detection of adjacent ones of reference bits spread across the disk,
wherein the average time is measured in a quiescent mode of the disk drive.
5. The disk drive according to claim 4 , wherein the disk sector structure further comprises:
a preamble;
a servo address mark block adjacent said preamble;
a track block adjacent said servo address mark block;
a sector number adjacent said track block;
a position error signal burst block adjacent said average time block; and
a data block adjacent said position error signal burst block.