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. 08, 1998
Filed:
Feb. 03, 1997
Applicant:
Inventor:
Shinichi Tanaka, Kamakura, JP;
Assignee:
Nikon Corporation, Tokyo, JP;
Attorney:
Primary Examiner:
Int. Cl.
CPC ...
G11B / ;
U.S. Cl.
CPC ...
369 59 ; 369124 ; 369 47 ; 360 48 ;
Abstract
When performing data reproduction based on the partial response method, a reference pattern detection circuit detects the reference pattern directly from the reproduced signal that is supplied from a low pass filter, and supplies a timing signal to a calculation circuit. Based on the timing signal, the calculation circuit determines threshold levels that are used for data decoding in a decoder circuit based on the output level of an A/D converter circuit. As a result, a sector mark, which previously was used as a reference mark for reference pattern detection, does not need to be provided in the recording medium, thereby increasing the recording capacity for user data.