Drew M Mader

US Patent:

20190287554, Sep 19, 2019

Filed:

Oct 25, 2018

Appl. No.:

16/170445

Inventors:

- Cupertino CA, US
Franklin P. Martens - Bloomington MN, US
Drew Michael Mader - Minneapolis MN, US
Steven J. Kimble - Chanhassen MN, US
James E. Angelo - Savage MN, US

International Classification:

G11B 5/02
G11B 5/60

Abstract:

A temperature compensation equation is generated during manufacture of a heat-assisted magnetic recording (HAMR) disk drive using initial total currents supplied to a laser diode of the disk drive at different initial operating temperatures. The total currents represent currents for recording data to or erasing data from the medium. The temperature compensation equation is stored in the disk drive, and updated, during field operation, using a subsequent total current associated with an operating temperature differing from the initial operating temperatures. The total current supplied to the laser diode for a subsequent write operation is adjusted using the updated temperature compensation equation in response to the operating temperature at the time of the subsequent write operation.

US Patent:

20170092318, Mar 30, 2017

Filed:

Apr 11, 2016

Appl. No.:

15/095380

Inventors:

- Cupertino CA, US
Drew Michael Mader - Minneapolis MN, US
Wenzhong Zhu - Apple Valley MN, US
Michael A. Cordle - Eagan MN, US

International Classification:

G11B 7/1267
G11B 20/18

Abstract:

During field operation of a heat-assisted magnetic recording data storage device, a laser adjustment procedure is performed. The laser adjustment procedure involves writing on a recording medium at least three tracks. If a bit error rate of a middle tracks has increased, the laser current is swept while recording test tracks to determine a new laser current that results in a minimum bit error rate. The new laser current is used for subsequent write operations.