The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Feb. 20, 2007
Filed:
Dec. 27, 2005
Xiaodong Che, Saratoga, CA (US);
Weidong Huang, San Jose, CA (US);
Terence Tin-lok Lam, Cupertino, CA (US);
Zhong-heng Lin, Santa Clara, CA (US);
Alex Shteyn, Sunnyvale, CA (US);
Xiaodong Che, Saratoga, CA (US);
Weidong Huang, San Jose, CA (US);
Terence Tin-Lok Lam, Cupertino, CA (US);
Zhong-heng Lin, Santa Clara, CA (US);
Alex Shteyn, Sunnyvale, CA (US);
Hitachi Global Storage Technologies Netherlands B.V., Amsterdam, NL;
Abstract
A system and method for calibrating and controlling a magnetic recording disk drive fly-height actuator uses the signal from the magnetoresistive (MR) read head to determine head-disk contact (HDC). The MR signal is measured over a low-frequency range, with the slider out-of-contact with the disk, to develop a reference value. The MR signal is then measured over the same low-frequency range and if it exceeds the reference value by some predetermined amount, this is an indication of HDC. The fly-height actuator control signal value for HDC is recorded and thus corresponds to a head-disk spacing of zero. The calibration method also determines the sensitivity of head-disk spacing to the fly-height actuator control signal by measuring a series of MR read signal amplitudes for a corresponding series of control signals. The fly-height actuator is calibrated from the sensitivity and the value of control signal that results in zero head-disk spacing, and can then be controlled to move the head to a desired fly height and maintain it at the desired fly height.