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. 22, 2011
Filed:
Jan. 27, 2009
Hiroyasu Masuda, Kanagawa, JP;
Yoshihiko Maeda, Kanagawa, JP;
Kenichi Kuramoto, Kanagawa, JP;
Masayuki Kurita, Kanagawa, JP;
Kenji Kuroki, Kanagawa, JP;
Hiroyasu Masuda, Kanagawa, JP;
Yoshihiko Maeda, Kanagawa, JP;
Kenichi Kuramoto, Kanagawa, JP;
Masayuki Kurita, Kanagawa, JP;
Kenji Kuroki, Kanagawa, JP;
Hitachi Global Storage Technologies, Netherlands, B.V., Amsterdam, NL;
Abstract
Embodiments of the present invention precisely measure clearance variation by temperature change using a value in a RW channel. In an embodiment of the present invention, an HDD measures resolution by signals in a RW channel. The measured resolution shows variations depending on temperature according to two factors. One factor is the clearance variation depending on the temperature and the other is the variation in operational property of the RW channel depending on the temperature. The HDD compensates for the temperature variation of the resolution according to the two factors. The HDD uses two kinds of sensed temperature. One corresponds to the temperature inside an enclosure in which head sliders are provided and the other corresponds to the temperature of the chip in which the RW channel is implemented. Sensing the drive temperature and the channel temperature independently achieves precise compensation for the variation in the measured resolution caused by clearance variation and channel property.