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:
Nov. 25, 2008
Filed:
Mar. 08, 2006
Masaki Yoshioka, Kanagawa, JP;
Akira Kojima, Kanagawa, JP;
Toshiyuki Konishi, Kanagawa, JP;
Hitachi Global Storage Technologies Netherlands B.V., Amsterdam, NL;
Abstract
Embodiments of the invention prevent a magnetic head from coming into contact with a protrusion on a magnetic disk. In one embodiment, a head gimbal assembly includes a piezoelectric actuator for changing the flying height of a head/slider assembly. The address of a protrusion on a magnetic disk is preregistered in a nonvolatile memory. When a seek operation or following operation is to be performed, the head/slider assembly flies at a reference flying height. Before the protrusion passes below the head/slider assembly, an operating voltage is applied to the piezoelectric actuator to increase the flying height. After the protrusion passes below the head/slider assembly, the head/slider assembly flies at the reference flying height with operating voltage application stopped.