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:
Mar. 06, 2007
Filed:
Jan. 03, 2003
Applicants:
Fumio Isshiki, Kokubunji, JP;
Tetsuya Nishida, Tokyo, JP;
Inventors:
Fumio Isshiki, Kokubunji, JP;
Tetsuya Nishida, Tokyo, JP;
Assignee:
Hitachi, Ltd., Tokyo, JP;
Primary Examiner:
Assistant Examiner:
Int. Cl.
CPC ...
G11B 7/24 (2006.01);
U.S. Cl.
CPC ...
Abstract
A high recording-density and highly reliable optical disc according to the two-dimensional PRML system is provided in which periodic signal fluctuations in the readout signal caused by an overall positional displacement of pits between adjacent tracks can be detected at each sampling clock timing and can be tracked and compensated. Two-dimensional inter-symbol interference is compensated during the production and recording of the pattern of the medium. The readout signal is compensated by a process of multi-value tracking before symbols are extracted from the signal.