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:
Sep. 23, 2008
Filed:
Jan. 26, 2004
Yutaka Kashihara, Chigasaki, JP;
Yuji Nagai, Kawasaki, JP;
Shuichi Ookubo, Tokyo, JP;
Masatsugu Ogawa, Tokyo, JP;
Masaki Nakano, Tokyo, JP;
Toshiaki Iwanaga, Tokyo, JP;
Yutaka Kashihara, Chigasaki, JP;
Yuji Nagai, Kawasaki, JP;
Shuichi Ookubo, Tokyo, JP;
Masatsugu Ogawa, Tokyo, JP;
Masaki Nakano, Tokyo, JP;
Toshiaki Iwanaga, Tokyo, JP;
Kabushiki Kaisha Toshiba, Tokyo, JP;
NEC Corporation, Tokyo, JP;
Abstract
Reproduction signals include patterns for which recognition errors are likely. With respect to such patterns, probable error patterns are prepared. Tables showing correct patterns and error patterns are prepared, and evaluation values accurately representing signal quality are calculated. In an apparatus using a PRML method, discrimination data and a plurality of predetermined bit sequence pairs are examined to detect matching. A bit sequence and corresponding two ideal responses are calculated. Euclidean distances between the two ideal responses and equalization signals are obtained, and the difference between the Euclidean distances is further obtained. A quality evaluation value of a reproduction signal is calculated based on a mean value, a standard deviation, an appearance probability of the predetermined bit sequence, and a Hamming distance between the predetermined bit sequence pairs.