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:
Jul. 07, 2009
Filed:
Aug. 02, 2005
Applicants:
Takahiro Kurokawa, Fujisawa, JP;
Hiroyuki Minemura, Kokubunji, JP;
Mariko Umeda, Fuchu, JP;
Harukazu Miyamoto, Higashimurayama, JP;
Inventors:
Takahiro Kurokawa, Fujisawa, JP;
Hiroyuki Minemura, Kokubunji, JP;
Mariko Umeda, Fuchu, JP;
Harukazu Miyamoto, Higashimurayama, JP;
Assignee:
Hitachi, Ltd., Tokyo, JP;
Primary Examiner:
Int. Cl.
CPC ...
G11B 7/00 (2006.01);
U.S. Cl.
CPC ...
Abstract
The amount of focus offset and the amount of spherical aberration correction are adjusted with respect to a disk on which no data is recorded with high precision. The amount of focus offset and the amount of spherical aberration correction are adjusted on the basis of (1) a focus error signal amplitude, (2) a tracking error signal amplitude in a wide track pitch region, and (3) a rectangular waveform wobble signal envelop level.