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:
Aug. 05, 2014
Filed:
Jun. 14, 2012
Hiroyasu Tanabe, Yokohama, JP;
Hideki Zaitsu, Fujisawa, JP;
Kyo Akagi, Fuchu, JP;
Naoto Ito, Fujisawa, JP;
Hiroyasu Tanabe, Yokohama, JP;
Hideki Zaitsu, Fujisawa, JP;
Kyo Akagi, Fuchu, JP;
Naoto Ito, Fujisawa, JP;
HGST Netherlands B.V., Amsterdam, NL;
Abstract
SMR disk drives are described that adjust track pitch or magnetic write width to compensate for external temperature effects. In one embodiment track pitch is increased when the media temperature increases. The temperature of magnetic media during write operations can be determined from the drives' temperature sensor. In other embodiments track pitch is adjusted based on the magnetic write width (MWW) which is determined from read-back testing of previously written data tracks. In an alternative embodiment, the width of the MWW is adjusted instead of the track pitch. The various factors that affect the MWW that can be used to increase or decrease the MWW, including write current characteristics and when available thermal-assistance parameters.