Write current parameter selection for magnetic recording

• US 9,805,741 B1
• Filed: 01/27/2017
• Issued: 10/31/2017
• Est. Priority Date: 01/29/2016
• Status: Active Grant

• Current Assignee: Seagate Technology LLC (Seagate Technology Holdings Plc)
• Original Assignee: Seagate Technology LLC (Seagate Technology Holdings Plc)
• Inventors: Ma, Minjie, Granz, Steven, Gao, Kaizhong
• Primary Examiner(s): Wong, K.
• Application Number:
  US15/417,661
• Time in Patent Office: 277 Days
• Field of Search: None
• CPC Class Codes: G11B 20/105 selecting parameter values from a plurality of predetermined settings
• CPC Class Codes: G11B 2005/0021 Thermally assisted recording using an auxiliary energy source for heating the recording layer locally to assist the magnetization reversal
• CPC Class Codes: G11B 5/012 Recording on, or reproducing or erasing from, magnetic disks G11B17/00, G11B19/00 take precedence
• CPC Class Codes: G11B 5/02 Recording, reproducing, or erasing methods; Read, write or erase circuits therefor
• CPC Class Codes: G11B 5/09 Digital recording

Abstract

A storage device includes a storage medium and a storage device controller that selectively varies a value of at least one write current parameter to generate alternating data tracks of variable written track width. According to one implementation, the alternating data tracks of variable written track width are generated with a single writer.

Claims

1. Apparatus comprising:

a storage medium; and

a storage device controller that selectively varies a value of at least one write current parameter to write alternating data tracks of variable written track width on the storage medium.

2. The apparatus of claim 1, wherein the alternating data tracks of variable written track width are written by a same writer.

3. The apparatus of claim 1, wherein the write current parameter is one of write current amplitude, write current overshoot amplitude, write current rise time, and write current overshoot duration.

4. The apparatus of claim 1, wherein the storage device controller generates write current with a first set of values for write current parameters when writing data to a pair of non-adjacent data tracks on the storage medium and generates the write current with a second different set of values for the write current parameters when writing data to a third data track between and directly adjacent to the non-adjacent data tracks.

5. The apparatus of claim 4, wherein generating write current with the first set of values and the second set of values further comprises:

retrieving values for the write current parameters stored in association with a radial zone of the storage medium including the pair of non-adjacent data tracks and the third data track; and

generating write current with the retrieved values.

6. The apparatus of claim 1, wherein the storage device controller is further configured to generate write current with a first set of values of write current parameters when writing data to a first series of alternating data tracks including every other data track in a radial zone and to generate write current with a second set of values of the write current parameters when writing data to a second set of alternating data tracks interlaced with the first set of alternating data tracks.

7. The apparatus of claim 1, wherein the storage device controller is further configured to store the first set of write current parameter values and the second set of write current parameter values in memory of a storage device in association with a radial zone including the pair of non-adjacent data tracks and the third data track.

8. The apparatus of claim 1, wherein the storage device controller is further configured to store a different set of write current parameter values in association with each of a plurality of radial zones on the storage medium.

9. The apparatus of claim 1, wherein the alternating data tracks are written at two different linear densities.

10. A method comprising:

defining a first set of values for write current parameters for use when writing data to a pair of non-adjacent data tracks on a storage medium; and

defining a second different set of values for the write current parameters for use when writing data to a third data track interlaced with the pair of non-adjacent data tracks.

11. The method of claim 10, wherein the first set of values for the write current parameters is defined in association with a first linear density of data and the second set of values for the write current parameters is defined in association with a second linear density of data.

12. The method of claim 10, wherein defining the first set of values or the second set of values further comprises performing a three-dimensional optimization to select steady state write current amplitude, write overshoot amplitude, and write current overshoot duration.

13. The method of claim 10, wherein defining the first set of values for the write current parameters or the second set of values for the write current parameters further comprises:

fixing at least one value of a write current parameter selected from a group consisting of steady state write current amplitude, write current duration, write current rise time, and write current overshoot while writing data with varied values of at least one other write current parameter selected from the group.

14. The method of claim 10, further comprising:

storing the first set of write current parameter values and the second set of write current parameter values in memory of a storage device in association with a radial zone including the pair of non-adjacent data tracks and the third data track.

15. The method of claim 10, wherein the defined first set of values is stored in association with a first set of alternating data tracks including every other data track in a radial zone and the defined second set of values is stored in association with a second set of alternating data tracks interlaced with the first set of alternating data tracks in the radial zone.

16. The method of claim 10, wherein the storage medium is included in a heat-assisted magnetic recording device.

17. The method of claim 10, wherein the storage medium is included in a perpendicular magnetic recording device.

18. One or more tangible computer-readable storage media encoding computer-executable instructions for executing on a computer system a computer process, the computer process comprising:

selectively varying a value of at least one write current parameter to write alternating data tracks of variable written track width with a same writer.

19. The one or more tangible computer-readable storage media of claim 18, wherein the computer process further comprises:

generating write current with a first set of values of write current parameters when writing data to a pair of non-adjacent data tracks on the storage medium; and

generating the write current with a second different set of values of the write current parameters when writing data to a third data track between and directly adjacent to the non-adjacent data tracks.

20. The one or more tangible computer-readable storage media of claim 19, wherein the write current parameters include steady state write current amplitude, overshoot amplitude, rise time, and overshoot duration.