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. 15, 2011
Filed:
Dec. 04, 2009
Chikako Sakagami, Kanagawa, JP;
Kazuhisa Shishida, Kanagawa, JP;
Isao Yoneda, Kanagawa, JP;
Kazuaki Usui, Kanagawa, JP;
Hiroshi Uchida, Kanagawa, JP;
Takeshi Saito, Kanagawa, JP;
Kenji Tomida, Kanagawa, JP;
Takenori Atsumi, Ibaraki-ken, JP;
Chikako Sakagami, Kanagawa, JP;
Kazuhisa Shishida, Kanagawa, JP;
Isao Yoneda, Kanagawa, JP;
Kazuaki Usui, Kanagawa, JP;
Hiroshi Uchida, Kanagawa, JP;
Takeshi Saito, Kanagawa, JP;
Kenji Tomida, Kanagawa, JP;
Takenori Atsumi, Ibaraki-ken, JP;
Hitachi Global Storage Technologies, Netherlands B.V., Amsterdam, NL;
Abstract
A disk drive. The disk drive includes a head, a moving mechanism, a first peak filter, an adaptive peak filter, and a filter controller. The head is configured to read servo data on a disk at sampling frequency. The moving mechanism is configured to move the head in proximity with a recording surface of the disk. The first peak filter has a fixed peak frequency and a variable gain, and is configured to be inserted into a servo loop. The servo loop is configured to position the head with position error signals between servo data read by the head and a target position. The adaptive peak filter has a variable peak frequency and a variable gain, and is configured to be inserted into the servo loop. The filter controller is configured to control the gain of the adaptive peak filter according to the gain of the first peak filter.