Shingled magnetic recording for writing tracks of variable track width

• US 10,008,231 B2
• Filed: 10/26/2017
• Issued: 06/26/2018
• Est. Priority Date: 05/13/2016
• Status: Active Grant

• Current Assignee: Seagate Technology LLC (Seagate Technology Holdings Plc)
• Original Assignee: Seagate Technology LLC (Seagate Technology Holdings Plc)
• Inventors: Granz, Steven, Gage, Edward, Chu, Alfredo, Zhu, Wenzhong
• Primary Examiner(s): Dinh, Tan X
• Application Number:
  US15/795,044
• Publication Number:
  US 20180047422A1
• Time in Patent Office: 243 Days
• Field of Search: None
• CPC Class Codes: G11B 20/1217 on discs
• 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 2020/1238 track, i.e. the entire a spirally or concentrically arranged path on which the recording marks are located
• 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 5/6088 Optical waveguide in or on flying head
• CPC Class Codes: G11B 7/126 Circuits, methods or arrangements for laser control or stabilisation
• CPC Class Codes: G11B 7/1263 Power control during transducing, e.g. by monitoring
• CPC Class Codes: G11B 7/1267 Power calibration

Abstract

A storage device includes a storage controller configured to operate a heat-assisted magnetic recording head to write data to a band of consecutive data tracks in a consecutive track order while selectively alternating a power level of the heat source when writing to some data tracks of the band.

Claims

1. A system comprising:

a storage medium including a data band of consecutive data tracks, the data band including first series of alternating data tracks and a second series of alternating data tracks interlaced with the first series, each data track of the first series overlapping a previously-written track by a first offset and each data track of the second series overlapping a previously-written track by a second offset different than the first offset; and

a storage device controller configured to write data to the data band in a consecutive track order.

2. The system of claim 1, wherein the first offset is a non-zero offset and the second offset is a zero offset.

3. The system of claim 1, wherein the data tracks of the first series have a different written track width than the data tracks of the second series.

4. The system of claim 1, wherein the storage device controller is configured to operate a heat source of a heat-assisted magnetic recording (HAMR) head at a first level when writing the data to the first series of alternating data tracks and configured to operate the heat source at a second different level when writing to the second series of alternating data tracks.

5. The system of claim 1, wherein the storage device controller is further configured to write data of a first linear density to the first series of alternating tracks in the data band and to write data of a second linear density to the second series of alternating data tracks in the data band.

6. The system of claim 1, wherein data tracks of the data band are arranged according to a uniform track pitch.

7. The system of claim 1, wherein the data band of consecutive data tracks is a shingled data band in a shingled magnetic recording system.

8. The system of claim 1, wherein all data tracks of the data band have a substantially uniform effective track width.

9. A method comprising:

receiving an instruction to write data to a data band of consecutive data tracks on the storage medium according to a consecutive track order; and

writing the data to the data band according to the consecutive track order, the data band including a first series of alternating data tracks and a second series of alternating data tracks interlaced with the first series, wherein each data track of the first series overlaps a previously-written track by a first offset and each data track of the second series overlapping a previously-written data track by a second different offset.

10. The method of claim 9, wherein the first offset is a non-zero offset and the second offset is a zero offset.

11. The method of claim 9, wherein the data tracks of the first series have a different written track width than the data tracks of the second series.

12. The method of claim 9, further comprising:

writing data of a first linear density to the first series of alternating tracks in the data band and writing data of a second linear density to the second series of alternating data tracks in the data band.

13. The method of claim 9, wherein data tracks of the data band are arranged according to a uniform track pitch.

14. The method of claim 9, wherein the data band of consecutive data tracks is a shingled data band in a shingled magnetic recording system.

15. A method comprising:

writing data consecutively to a first subset of consecutive data tracks in a data band by generating a magnetic footprint of a first width at a surface of a storage medium;

subsequent to the writing of the data to the first subset of the consecutive data tracks, writing data to a last data track of the consecutive data tracks in the data band by generating a magnetic field of a second different width at the surface of the storage medium, the second different width smaller than the first width.

16. The method of claim 15, wherein the data band has a uniform track pitch.

17. The method of claim 15, writing data to a last data track in the data band further comprises shifting a center of the last data track closer to an adjacent data track when reducing width of the magnetic footprint from the first width to the second width.

18. The method of claim 15, wherein writing the data to the last data track of the consecutive data tracks in the data band further comprises decreasing power of a heat source of a heat-assisted magnetic recording (HAMR) head.

19. The method of claim 15, wherein all data tracks in the data band are defined by a substantially uniform effective track width.

20. The method of claim 15, wherein the data band is a shingled data band.