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:
Apr. 17, 2007
Filed:
May. 24, 2002
Tetsuya Okumura, Neyagawa, JP;
Jun Akiyama, Kashihara, JP;
Tomiyuki Numata, Tenri, JP;
Shigemi Maeda, Yamatokoriyama, JP;
Masanori Ushioda, Tenri, JP;
Tetsuya Okumura, Neyagawa, JP;
Jun Akiyama, Kashihara, JP;
Tomiyuki Numata, Tenri, JP;
Shigemi Maeda, Yamatokoriyama, JP;
Masanori Ushioda, Tenri, JP;
Sharp Kabushiki Kaisha, Osaka, JP;
Abstract
A signal evaluation device for evaluating a decoded signal of maximum likelihood decoding includes: a differential metric circuit for finding differential metrics; comparators for judging whether a difference of differential metrics exceeds a predetermined threshold; counters for counting respective output pulses of the comparators; and a controller for finding the probability of the differential metrics falling at or below the predetermined threshold, based on the number of measured samples and the number of samples counted by the counters, and processing the probability by arithmetic operations so as to obtain an index of signal evaluation. With this arrangement, signal evaluation devices for evaluating a recording medium or a recording medium driving device can have a simpler structure and can perform evaluations in a plurality of PR modes.