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. 06, 2005
Filed:
Dec. 14, 2001
Kensuke Fujimoto, Kanagawa, JP;
Shunji Yoshimura, Tokyo, JP;
Atsushi Fukumoto, Kanagawa, JP;
Yasuhito Tanaka, Tokyo, JP;
Kensuke Fujimoto, Kanagawa, JP;
Shunji Yoshimura, Tokyo, JP;
Atsushi Fukumoto, Kanagawa, JP;
Yasuhito Tanaka, Tokyo, JP;
Sony Corporation, Tokyo, JP;
Abstract
The present invention provides an apparatus and a method for precisely and adequately evaluating actual quality of reproduced data whenever applying a maximum likelihood decoder for converting signal reproduced from a recording medium into binary signal. Based on data arrays of a pair of binary data outputted from a 'Viterbi' decoder, SAM values are secured by selecting any of path-metric differential values (00) and (11) being the difference between a pair of values compared when renewing path-metric values PMM (00) and (11) outputted from the 'Viterbi' decoder. The minimum SAM value for an ideally-reproduced signal is outputted from a constant generating circuit. If the SAM values are verified as valid, and yet, if the SAM values coincide with the equation “input SAM values”≦“data value outputted from the constant generating circuit”, then squared values outputted from a square circuit are averaged by an averaging circuit. Finally, the average value is outputted as the reproduced signal evaluation.