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. 04, 2012
Filed:
Dec. 17, 2008
Applicants:
Takeyoshi Kataoka, Yokohama, JP;
Seiji Imagawa, Yokohama, JP;
Munehiro Yonezawa, Tokyo, JP;
Inventors:
Assignees:
Hitachi, Ltd., Tokyo, JP;
Hitachi-LG Data Storage, Inc., Tokyo, JP;
Primary Examiner:
Assistant Examiner:
Int. Cl.
CPC ...
G11B 7/00 (2006.01);
U.S. Cl.
CPC ...
Abstract
An optical disc device capable of preventing a current larger than prescribed in specifications from flowing by measuring amounts of variation in drive signals of the actuator or the spindle motor, and in view of a correlation between those amounts of variation in the drive signals and the amount of current, changing the servo control system characteristics according to measured amounts of variation, and setting a limit to the level of drive signals.