Patent ID: 7187635
Filing Date: 2007-03-06
Classification: G11B

Abstract:
1. An optical information reproducing method of detecting a reproduced signal on a basis of a record mark formed in an optical information recording medium and decoding record data on a basis of the reproduced signal, comprising the steps of: decoding a record data on a basis of the reproduced signal; detecting a mark length of each record mark on a basis of a reproduced signal; and correcting a waveform of the reproduced signal before the decoding by a correction amount corresponding to the detected mark length, wherein the correction amount is an amount that compensates fluctuation of a record mark edge by a stray magnetic field, and wherein, when the correction amount is J, the correction amount J satisfies a relational expression: J=−A·n(k)+B·n(k+1), wherein A and B are constants, n(k) is a mark length at one previous time unit, and n(k+1) is a mark length at present time unit.