Data storage device maximizing areal density based on a target quality metric

• US 9,230,605 B1
• Filed: 12/01/2014
• Issued: 01/05/2016
• Est. Priority Date: 12/01/2014
• Status: Active Grant

• Current Assignee: JP Morgan Chase Bank, N.A. (JP Morgan Chase & Co)
• Original Assignee: Western Digital Technologies Incorporated (Western Digital Corporation)
• Inventors: Moser, Andreas, Nguyen, Thien
• Primary Examiner(s): Hindi, Nabil
• Application Number:
  US14/556,645
• Time in Patent Office: 400 Days
• Field of Search: 369/120, 369/121, 369/47.27, 369/47.5, 369/47.51, 369/47.52, 369/47.53, 369/116, 360/31, 360/68
• US Class Current: 1/1
• CPC Class Codes: G11B 20/10009 Improvement or modification of read or write signals
• CPC Class Codes: G11B 20/10305 signal quality assessment
• CPC Class Codes: G11B 20/10481 optimisation methods
• CPC Class Codes: G11B 27/36 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 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

Abstract

A data storage device is disclosed comprising a head actuated over a disk. Data is written to the disk and read from the disk to measure a quality metric. A recording parameter is repeatedly adjusted and the quality metric is measured for each adjustment of the recording parameter. An operating value for the recording parameter is selected that corresponds to a substantially maximum areal density for the disk when the measured quality metric substantially matches a target quality metric.

Claims

1. A data storage device comprising:

a disk;

a head actuated over the disk; and

control circuitry configured to;

write data to the disk and read the data from the disk to measure a quality metric;

repeatedly adjust a recording parameter and measure the quality metric for each adjustment of the recording parameter; and

select an operating value for the recording parameter that corresponds to a substantially maximum areal density for the disk when the measured quality metric substantially matches a target quality metric.

2. The data storage device as recited in claim 1, wherein the recording parameter comprises the areal density for the disk.

3. The data storage device as recited in claim 1, wherein the recording parameter comprises a write current applied to a write element.

4. The data storage device as recited in claim 1, wherein the recording parameter comprises a write power applied to a laser configured to heat the disk during write operations.

5. The data storage device as recited in claim 1, wherein the control circuitry is further configured to adjust the recording parameter based on a nominal function that estimates a relationship between the recording parameter and the target quality metric.

6. The data storage device as recited in claim 5, wherein the control circuitry is further configured to generate the nominal function based on at least one recording parameter setting where the corresponding measured quality metric substantially matches the target quality metric.

7. The data storage device as recited in claim 6, wherein the control circuitry is further configured to generate the nominal function based on at least two recording parameter settings where the corresponding measured quality metric for each recording parameter substantially matches the target quality metric.

8. The data storage device as recited in claim 1, wherein the quality metric comprises an off-track read capability.

9. The data storage device as recited in claim 1, wherein the quality metric comprises an error rate.

10. The data storage device as recited in claim 1, wherein the quality metric comprises a squeeze margin.

11. A method of operating a data storage device, the method comprising:

writing data to a disk and reading the data from the disk to measure a quality metric;

repeatedly adjusting a recording parameter and measuring the quality metric for each adjustment of the recording parameter; and

selecting an operating value for the recording parameter that corresponds to a substantially maximum areal density for the disk when the measured quality metric substantially matches a target quality metric.

12. The method as recited in claim 11, wherein the recording parameter comprises the areal density for the disk.

13. The method as recited in claim 11, wherein the recording parameter comprises a write current applied to a write element.

14. The method as recited in claim 11, wherein the recording parameter comprises a write power applied to a laser configured to heat the disk during write operations.

15. The method as recited in claim 11, further comprising adjusting the recording parameter based on a nominal function that estimates a relationship between the recording parameter and the target quality metric.

16. The method as recited in claim 15, further comprising generating the nominal function based on at least one recording parameter setting where the corresponding measured quality metric substantially matches the target quality metric.

17. The method as recited in claim 16, further comprising generating the nominal function based on at least two recording parameter settings where the corresponding measured quality metric for each recording parameter setting substantially matches the target quality metric.

18. The method as recited in claim 11, wherein the quality metric comprises an off-track read capability.

19. The method as recited in claim 11, wherein the quality metric comprises an error rate.

20. The method as recited in claim 11, wherein the quality metric comprises a squeeze margin.