Selective write power variability for magnetic recording

Patent metadata

Field	Value
Publication number	US-9805752-B2
Application number	US-201514938298-A
Country	US
Kind code	B2
Filing date	Nov 11, 2015
Priority date	Nov 11, 2015
Publication date	Oct 31, 2017
Grant date	Oct 31, 2017

Abstract

A storage device includes a storage controller that controls a writer to generate a magnetic field at an air-bearing surface (ABS) of a storage medium and to selectively alter a strength of the magnetic field by a predetermined amount when writing data to select data tracks on the storage medium.

First claim

What is claimed is:

1. Apparatus comprising:
a storage controller that controls a writer to generate a magnetic field at an air-bearing surface (ABS) of a storage medium and selectively alters a strength of the magnetic field incident on the ABS by a predetermined amount when writing data to a last data track in a data band of shingled magnetic data tracks on the storage medium.

2. The apparatus of claim 1 , wherein the storage controller writes data consecutively to consecutive data tracks in the data band and decreases the strength of the magnetic field when writing to the last data track in the data band.

3. The apparatus of claim 1 , wherein the storage controller alters the strength of the magnetic field by altering a fly height of a writer by a select amount.

4. The apparatus of claim 2 , wherein the magnetic field is of a lower strength at the ABS when writing data to the last data track in the series than when writing to other data tracks in the series.

5. The apparatus of claim 2 , wherein the last data track in the data band has a wider written track width than all other data track on the storage medium.

6. The apparatus of claim 1 , wherein selectively altering the strength of the magnetic field further comprises:
increasing a clearance between a writer and the ABS.

7. The apparatus of claim 1 , wherein the storage controller is further configured to increase a linear density of data when writing to the last data track in the data band as compared to all other data tracks in the data band.

8. The apparatus of claim 1 , wherein selectively altering the strength of the magnetic field further comprises:
decreasing a write current provided to a writer of the storage device.

9. The apparatus of claim 1 , wherein the last data track in the data band is defined to have a different track pitch than other data tracks of the data band.

10. Apparatus comprising:
a storage device controller configured to increase fly height of a writer by a predetermined amount when writing data to select data tracks on a storage medium to decrease a written width of the select data tracks.

11. The apparatus of claim 10 , wherein the storage device controller increases the fly height in order to decrease strength of a magnetic field at an air-bearing surface (ABS) of the storage medium by a predetermined amount.

12. The apparatus of claim 10 , wherein the storage device controller is further configured to set the fly height to a first value when writing to a first data track and set the fly height to a second value when writing data to a second adjacent data track.

13. The apparatus of claim 10 , wherein the storage device controller is further configured to write data consecutively to consecutive data tracks in a series and to increase the fly height to write data to a last data track in the series.

14. The apparatus of claim 11 , wherein the consecutive data tracks in the series form a data band in a shingled magnetic recording (SMR) system.

15. Apparatus comprising:
a storage device controller that alters a write current parameter by a predetermined amount when writing data to a last data track in a data band of shingled magnetic data tracks on a storage medium to decrease a written width of the last data tracks.

16. The apparatus of claim 15 , wherein the storage device controller is further configured to write data consecutively to consecutive data tracks in the data band with the write current parameter set to a first value and to write data to the last data track in the data band with the write current parameter set to a second decreased value.

17. The apparatus of claim 15 , wherein the storage controller alters the strength of the magnetic field by altering a fly height of a writer by a select amount.

18. The apparatus of claim 15 , wherein the last data track is defined to have a different track pitch than other data tracks of the data band.

19. The apparatus of claim 15 , wherein the storage device controller is further configured to increase a linear density of data when writing to the last data track of the data band.

20. The apparatus of claim 15 , wherein the write current parameter is at least one of write current amplitude, overshoot, and duration.

Assignees

• Seagate Technology Llc

Inventors

• Yoon Jung Min
• Chung Jae Myung
• Kim Hwajun

Classifications

• G11B5/012 Primary

  Recording on, or reproducing or erasing from, magnetic disks (G11B17/00, G11B19/00 take precedence) · CPC title

• G11B5/6041 Primary

  using magnetic forces · CPC title

• G11B2020/1238

  track, i.e. the entire a spirally or concentrically arranged path on which the recording marks are located · CPC title

• G11B5/6082

  Design of the air bearing surface · CPC title

• G11B20/1217

  on discs · CPC title