Patent ID: 7420905

Claim:
An information reproducing device reproducing a multivalued level from a reproduction signal of a recording medium in which a mark representing information of said multivalued level is recorded on a cell, the device comprising: an A/D converting unit converting said reproduction signal into digital data; a digital-data retaining unit retaining said digital data; a primary operation unit judging a multivalued level of said digital data according to the reproduction signal deriving only from the mark of a present cell; a judged-value retaining unit temporarily retaining the judged multivalued level judged by said primary operation unit; an ensuing cell level operation unit determining a multivalued level of an ensuing cell ensuing said present cell prior to re-judging the multivalued level of said present cell; a reference judged value selecting unit selecting either of the judged multivalued levels of a preceding cell preceding said present cell and said ensuing cell according to an amount of an inter-code interference from either of said preceding cell and said ensuing cell to the reproduction signal of said present cell; and a re-judgment operation unit re-judging the multivalued level of said present cell by referring to the judged multivalued level selected by said reference judged value selecting unit.