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:
Nov. 28, 2000
Filed:
Oct. 15, 1998
Applicant:
Inventors:
Michihiko Iida, Kanagawa, JP;
Kunihiko Miyake, Kanagawa, JP;
Assignee:
Sony Corporation, Tokyo, JP;
Attorney:
Primary Examiner:
Int. Cl.
CPC ...
G11B / ;
U.S. Cl.
CPC ...
369 4429 ; 369 4425 ; 369 4435 ; 2502015 ;
Abstract
A low-speed focus servo operation in which an objective lens is moved slowly is performed in a start process that is executed after mounting of an optical recording medium. On the other hand, a high-speed focus search operation in which the objective lens is moved fast is started when focusing is lost in a state that a focus servo operation is being performed. In the high-speed focus search operation, the focus servo characteristic is set to a modified version of a characteristic that is determined by a calibration operation that is performed in the start process.