HAMR drive fault detection system

Patent metadata

Field	Value
Publication number	US-9336831-B2
Application number	US-201414511756-A
Country	US
Kind code	B2
Filing date	Oct 10, 2014
Priority date	Oct 10, 2014
Publication date	May 10, 2016
Grant date	May 10, 2016

Abstract

An apparatus of the present disclosure includes a controller coupled to a read/write head wherein the controller is configured to perform various operations. More specifically, the controller is configured to monitor an operational parameter of the read/write head and to detect a fault based on the operational parameter. The fault indicates that a write enabling energy source is malfunctioning during a write operation. The controller is additionally configured, in response to the fault, to take remedial action to protect data associated with the write operation.

First claim

The invention claimed is:

1. A data storage apparatus, comprising:
a controller coupled to a HAMR read/write head, the controller configured to:
monitor an operational parameter of the HAMR read/write head;
detect a fault based on the operational parameter of the HAMR read/write head, wherein the fault indicates that a write enabling energy source configured to heat a recording medium is malfunctioning during a write operation; and
responsive to the fault, take remedial action to protect data associated with the write operation.

2. The apparatus of claim 1 , wherein the operational parameter comprises an operational parameter of a photodiode.

3. The apparatus of claim 1 , wherein the operational parameter comprises an operational parameter of a temperature sensor.

4. The apparatus of claim 1 , wherein the remedial action comprises reporting a fault status to a host.

5. The apparatus of claim 1 , wherein the remedial action comprises re-initiating the write operation with a following read verification.

6. The apparatus of claim 1 , wherein the fault is triggered based on the energy source operating outside a desired operating range and wherein the desired operating range is adjustable to prevent false indicators.

7. The apparatus of claim 6 , wherein the desired operating range is adjustable to accommodate aging of the apparatus.

8. A data storage system, comprising:
an energy source configured to heat a recording medium;
a read/write head configured to detect whether the energy source is heating the recording medium during a write operation; and
a controller coupled to the read/write head and configured to:
monitor an operational parameter of the read/write head;
detect a fault based on the operational parameter of the read/write head, wherein the fault indicates that the energy source used to heat the recording medium is malfunctioning during the write operation; and
responsive to the fault, take remedial action to protect data associated with the write operation.

9. The system of claim 8 , wherein the operational parameter comprises an operational parameter of at least one of a photodiode and a temperature sensor.

10. The system of claim 8 , wherein the remedial action comprises re-initiating the write operation with a following read verification.

11. The system of claim 8 , wherein the fault is triggered based on the energy source operating outside a desired operating range and wherein the desired operating range is adjustable to prevent false indicators or to accommodate the aging of the system.

12. A method, comprising:
initiating a heat-assisted magnetic (HAMR) write operation of data;
detecting whether sufficient heat has been provided to enable the HAMR write operation;
indicating a fault if sufficient heat has not been provided to enable the HAMR write operation; and
responding to the fault by protecting the data associated with the write operation.

13. The method of claim 12 , wherein detecting comprises detecting light, detecting temperature, or detecting both light and temperature to determine if sufficient heat has been provided to enable the HAMR write operation.

14. The method of claim 12 , further comprising reporting the fault.

15. The method of claim 12 , further comprising responding to the fault by reinitiating the write operation and initiating a subsequent read verification operation.

16. The method of claim 12 , wherein the fault is triggered based on the detected heat falling outside a desired operating range and wherein the desired operating range is adjustable to prevent false indicators.

17. An apparatus, comprising:
a controller coupled to a heat-assisted magnetic recording (HAMR) head, the controller configured to:
monitor an operational parameter of an energy source of the HAMR head configured to heat a recording medium during a write operation;
determine if the operational parameter is indicative of a fault of the energy source; and
initiate a remedial action comprising protecting data associated with the write operation if the operational parameter is indicative of the fault.

18. The apparatus of claim 17 , wherein the operational parameter comprises a threshold parameter and the operational parameter is determined to be indicative of a fault if the operational parameter is outside a threshold.

19. The apparatus of claim 18 , wherein the threshold parameter comprises a laser bias current, a laser active current, a laser forward voltage drop, a laser calibration value, a photodiode/photo-detector response value, a photodiode discontinuity, a differential-ended temperature coefficient of resistivity (DETCR) resistance, a DETCR temperature during write, a DETCR interface health monitor, a read-only bit error rate (BER) by head or a write or read BER by head and zone.

20. The apparatus of claim 17 , wherein the operational parameter comprises a non-threshold parameter and the non-threshold parameter comprises a drive temperature, a number of writer power-on hours, a type of background sectors written, a type of system zone writes, or the number of write operations started.

21. The apparatus of claim 17 , wherein the remedial action comprises an action other than, or in addition to, adjusting the operational parameter.

Assignees

• Seagate Technology Llc

Inventors

• Burnett Paul William
• Trantham Jon

Classifications

• G11B27/36 Primary

  Monitoring, i.e. supervising the progress of recording or reproducing {(for digital recording G11B20/00 and s.gr.; for monitoring, testing or measuring of TV recorders of the type covered by H04N5/76 and subgroups, see H04N17/06)} · CPC title

• G11B5/455 Primary

  Arrangements for functional testing of heads; Measuring arrangements for heads · CPC title

• G11B5/6088 Primary

  Optical waveguide in or on flying head · CPC title

• G11B5/4866

  the arm comprising an optical waveguide, e.g. for thermally-assisted recording · CPC title

• G11B2005/0021

  Thermally assisted recording using an auxiliary energy source for heating the recording layer locally to assist the magnetization reversal · CPC title