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:
Jun. 22, 2004
Filed:
Aug. 01, 2001
Applicant:
Inventor:
Yutaka Osada, Kanagawa-ken, JP;
Assignee:
Victor Company of Japan, Limited, Yokohama, JP;
Attorney:
Primary Examiner:
Int. Cl.
CPC ...
G11B 3/90 ;
U.S. Cl.
CPC ...
G11B 3/90 ;
Abstract
Of (A+B) signal and (C+D) signal for detecting a radial push-pull signal, the (A+B) signal is multiplied with a predetermined coefficient k. The predetermined coefficient k is changed appropriately depending on an error rate upon decoding a land pre-pit, a lens shift amount of an objective lens of an optical pickup, and the levels of a land pre-pit signal and a wobbling signal relative to the level of (A+B+C+D) signal. Consequently, the land pre-pit on an optical disc can be detected securely at a high precision at any time of recording time and reproduction time.