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:
Mar. 10, 2015
Filed:
Feb. 18, 2014
Sae Magnetics (H.k.) Ltd., Shatin, N.T., HK;
Headway Technologies, Inc., Milpitas, CA (US);
SAE Magnetics (HK) Ltd., Shatin, N.T., Hong Kong, unknown;
Headway Technologies, Inc., Milpitas, CA (US);
Abstract
Methods are provided for determining the heater power level of a dynamic flying height (DFH) type write head at which a touch down (TD) occurs. Each method makes use of the DC component of a head-disk interference (HDI) sensor and the determination of the TD heater energy is deduced from certain characteristics of the function relating heater power to HDI DC signal strength. Characteristics that provide reliable indication of a TD include points of minimum slope, structure of the slope's slope and the properties of a linear fit to the slope if the slope does not converge to a consistent value. It is found that the use of all methods in combination allow a reliable TD determination under virtually all conditions.