Writing high frequency pattern over a DC background to detect skip track erasure for a disk drive
AssigneeWestern Digital Technologies, Inc.
InventorsQingzhi Peng, Kathy X. Tang
Life of this patent
Estimating the term…
Abstract
A method of detecting skip track erasure for a head and disk of a disk drive is disclosed. N tracks are DC erased, and a periodic pattern is written to the disk at a target track within the DC erased tracks. The periodic pattern is substantially comprised of a high frequency component greater than 450 MHz. After writing the periodic pattern to the target track at least twice, at least two of the DC erased tracks other than the target track are read to generate respective read signals. The read signals are processed to detect a skip track erasure event.
Claims18
A method of detecting skip track erasure for a head and disk of a disk drive, the method comprising:
- DC erasing N tracks on the disk, where N is an integer greater than one;
- writing a periodic pattern to the disk at a target track within the N DC erased tracks, wherein the periodic pattern is substantially comprised of a high frequency component greater than 450 MHz;
- after writing the periodic pattern to the target track at least twice, reading at least two of the DC erased tracks other than the target track to generate respective read signals;
- and
- processing the read signals to detect a skip track erasure event.
A disk drive comprising:
- a disk;
- a head actuated over the disk;
- and
- control circuitry operable to:
- DC erase N tracks on the disk, where N is an integer greater than one;
- write a periodic pattern to the disk at a target track within the N DC erased tracks, wherein the periodic pattern is substantially comprised of a high frequency component greater than 450 MHz;
- after writing the periodic pattern to the target track at least twice, read at least two of the DC erased tracks other than the target track to generate respective read signals;
- and
- process the read signals to detect a skip track erasure event.
Dependencies are inferred from the claim text.