Method and apparatus for writing and using servo correction data

Patent metadata

Field	Value
Publication number	US-9318146-B2
Application number	US-201213459019-A
Country	US
Kind code	B2
Filing date	Apr 27, 2012
Priority date	Apr 27, 2011
Publication date	Apr 19, 2016
Grant date	Apr 19, 2016

Abstract

Methods and apparatuses for generating and using servo correction data are disclosed. In one embodiment, an apparatus may comprise a data storage medium having a first track and a second track, servo correction data for the first track and the second track stored on the first track, and no servo correction data stored on the second track, and a controller configured to correct servo errors based on the servo correction data. In another embodiment a method may comprise receiving servo information related to a first data storage medium having a first track and a second track, generating one or more position error signals (PES) based on the servo information, generating servo correction data based on the one or more PES, and storing the servo correction data for the first track and the second track on the first track.

First claim

What is claimed is:

1. An apparatus comprising:
a data storage medium having a first track and a second track;
first servo correction data corresponding only to the first track and second servo correction data corresponding only to the second track both of which are stored on the first track, and no servo correction data stored on the second track, wherein the first servo correction data and second servo correction data are different from each other; and
a controller configured to correct servo errors in the first track using the first servo correction data and configured to correct servo errors in the second track using the second servo correction data.

2. The apparatus of claim 1 wherein the data storage medium includes a third track, and the second track and the third track are written in a shingled manner where the second track is partially overwritten by the third track.

3. The apparatus of claim 1 wherein:
the first track includes at least a first servo frame and the second track includes at least a second servo frame, each servo frame including a servo data portion and a user data portion; and
the first and the second servo correction data for the first servo frame and the second servo frame are stored on the first track.

4. The apparatus of claim 3 wherein the first and the second servo correction data are stored as part of the servo data portion of the first track.

5. The apparatus of claim 3 wherein the first and the second servo correction data are stored in data sectors of the user data portion of the first track.

6. The apparatus of claim 1 wherein the first track has a track pitch greater than the second track.

7. The apparatus of claim 1 wherein the second track is immediately subsequent to the first track, and the second track includes a blank area corresponding to an area containing the first and the second servo correction data of the first track.

8. The apparatus of claim 1 further comprising N instances of servo correction data stored on every Nth track of the data storage medium, where N is a natural number.

9. The apparatus of claim 1 wherein the first and the second servo correction data are calculated based on position error signal (PES) data.

10. The apparatus of claim 9 wherein the controller is configured to output a signal based on the first and the second servo correction data for controlling a voice coil motor (VCM) driving unit to move a transducer head to write data on a preset position of the data storage medium.

11. A method comprising:
storing both first servo correction data generated from a servo error detected for a first track and second servo correction data generated from a servo error detected for a second track of a first data storage medium on the first track, wherein the first servo correction data corresponds only to the first track, wherein the second servo correction data corresponds only to the second track, wherein the first servo correction data and the second servo correction data are different from each other, and wherein servo correction data is not stored on the second track; and
correcting servo errors in the first track using the first servo correction data and correcting servo errors in the second track using the second servo correction data.

12. The method of claim 11 further comprising generating the first and the second servo correction data based on position error signals (PES) generated during the operations on the first data storage medium.

13. The method of claim 11 wherein the first data storage medium further includes a third track, and wherein the second track and the third track are written in a shingled manner where the second track is partially overwritten by the third track.

14. The method of claim 13 wherein the second track is immediately subsequent to the first track, and wherein the second track includes a blank area corresponding to an area containing the first and the second servo correction data of the first track.

15. The method of claim 11 further comprising storing the first and the second servo correction data to a second data storage medium; and
correcting servo errors in the first track and the second track of the first data storage medium using the first and the second servo correction data stored to the second data storage medium.

16. A method comprising:
receiving servo information from a first track;
receiving servo information from a second track;
generating a first position error signal (PES) based on the servo information received from the first track;
generating a second position error signal (PES) based on the servo information received from the second track; and
generating first servo correction data responsive to the first PES and second servo correction data responsive to the second PES, wherein the first and the second servo correction data for the first track and the second track are stored on the first track.

17. The method of claim 16 further comprising correcting servo errors in the first track using the first servo correction data and correcting servo errors in the second track using the second servo correction data.

18. The method of claim 17 further comprising:
reading the first and the second servo correction data from the first data storage medium;
storing the first and the second servo correction data to a second data storage medium;
correcting servo errors in the first track and the second track of the first data storage medium using the first and the second servo correction data stored to the second data storage medium.

19. The method of claim 18 wherein tracks of the first data storage medium are divided into servo data zones and user data zones, and further comprising storing the first and the second servo correction data to an area of the user data zone of the first track.

20. The method of claim 19 further comprising:
storing data to the first data storage medium in a shingled manner where the first track is partially overwritten by the second track; and
leaving a portion of the second track blank corresponding to the area of the first track storing the first and the second servo correction data.

Assignees

• Cho Hyung Joon
• Seagate Technology Llc

Inventors

• Cho Hyung Joon

Classifications

• G11B5/596

  for track following on disks {(G11B5/5526, G11B5/5552, G11B5/5565, G11B5/5582 take precedence)} · CPC title

• G11B20/10009 Primary

  Improvement or modification of read or write signals · CPC title

• G11B5/59655

  Sector, sample or burst servo format · CPC title

• G11B20/12

  Formatting, e.g. arrangement of data block or words on the record carriers {(within interface between computers and data recorders G06F3/06)} · CPC title

• G11B20/18

  Error detection or correction; Testing {, e.g. of drop-outs} · CPC title