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. 29, 2008
Filed:
Nov. 12, 2004
Nobuhiro Takeda, Tokyo, JP;
Motoyuki Suzuki, Yokohama, JP;
Nobuhiro Takeda, Tokyo, JP;
Motoyuki Suzuki, Yokohama, JP;
Hitachi Ltd., Tokyo, JP;
Hitachi-LG Data Storage, Inc., Tokyo, JP;
Abstract
An optical disk apparatus and an optical disk recording and reproducing method are provided in which an actuator can be controlled in stable fashion at the time of high-speed recording operation. Before performing the high-speed recording operation under servo control of average type, the learning of a servo signal of average type by application of a disturbance signal is carried out for both the servo control of continuous servo type for reproduction and the servo control of sample-and-hold type for low-speed recording operation. Based on the result of the learning, the gain is set for a servo loop of average servo type for high-speed recording operation.