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:
Apr. 22, 2003
Filed:
Sep. 26, 2001
Toshiharu Funaki, Kanagawa-ken, JP;
Shinji Honma, Kanagawa-ken, JP;
Kenichi Shitara, Kanagawa-ken, JP;
Hideki Mochiduki, Kanagawa-ken, JP;
Hitachi Electronics Engineering Co., Ltd., Tokyo, JP;
Abstract
A magnetic disk certifier includes a defect detector circuit comprising a low-pass filter for extracting a low frequency component of the read-out signal, the low frequency component containing a signal component of the error, a signal generator circuit for generating a signal having a predetermined frequency lower than the frequency of the read-out signal, a synthesizer circuit for synthesizing an output signal of the low-pass filter and the signal outputted from the signal generator circuit and a comparator for generating an error signal by comparing the synthesized signal from the synthesizer circuit with a predetermined reference level.