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. 16, 2010
Filed:
Dec. 05, 2005
Masato Taniguchi, Kanagawa, JP;
Michio Nakajima, Kanagawa, JP;
Kaoru Umemura, Kanagawa, JP;
Hitachi Global Storage Technologies Netherlands B.V., Amsterdam, NL;
Abstract
The present invention relates to providing the manufacturing method for a magnetic disk drive that includes the process steps of detecting and processing in a simplified way the defective sectors causing a reading error at low operating environmental temperatures. In one example, defective sectors are detected by read/write testing at high operating environmental temperatures from, for example, 40° C. to 65° C. Reading the data written on the defective sectors makes it obvious that the gain in a high-frequency band is reduced. After test data has been written onto each sector, the filtering coefficient of an FIR element that is set for a data-reading system is changed from the optimum value. The frequency gain is thus reduced. Next, the test data is read and the sectors that have caused a reading error are registered as defectives.