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:
Dec. 14, 2010
Filed:
Apr. 25, 2007
Masaomi Ikeda, Kanagawa, JP;
Takao Matsui, Kanagawa, JP;
Masahiko Koizumi, Kanagawa, JP;
Masato Taniguchi, Kanagawa, JP;
Kohji Nakao, Kanagawa, JP;
Hideaki Maeda, Kanagawa, JP;
Masaomi Ikeda, Kanagawa, JP;
Takao Matsui, Kanagawa, JP;
Masahiko Koizumi, Kanagawa, JP;
Masato Taniguchi, Kanagawa, JP;
Kohji Nakao, Kanagawa, JP;
Hideaki Maeda, Kanagawa, JP;
Hitachi Global Storage Technologies, Netherlands, B.V., Amsterdam, NL;
Abstract
Embodiments in accordance with the present invention provide a magnetic disk drive capable of achieving error recovery stably in a simple configuration in the event of thermal asperity (TA) and minimizing the error recovery time required, and a method for controlling the disk drive. According to one embodiment, if TA occurs, a cutoff frequency of a high-pass filter to which a data read signal is input is first increased and a loop gain of a low-order finite impulse response (FIR) filter connected in series to an FIR filter is also increased as high as possible. Next, a Viterbi decoder to which a signal is input from the low-order FIR filter provides feedback to the low-order FIR filter so that an input signal error becomes a minimum. Tap coefficients of the low-order FIR filter are thus optimized.