Patent ID: 8264932

Claim:
An adjusting method for a recording condition for use with an optical disc device that records data into an optical disc medium by using codes whose shortest run length is 2T and reproduces the recorded data by using an adaptive equalizing procedure and a PRML procedure, comprising: the adaptive equalizing procedure being a procedure in which a tap coefficient C n is set to a value obtained by averaging values of a tap coefficient a n renewed by a LMS method, located symmetrically with each other along the time axis; a step of generating a first binary bit array by binarizing the reproduced signal waveform reproduced from the optical disc medium in accordance with the PRML procedure; a step of generating a second binary bit array and a third binary bit array which are obtained by shifting a interested edge of the first binary bit array to the left and right, respectively; a step of generating first, second and third target signal waveforms corresponding to the first, second and third binary bit arrays, respectively; a step of generating a first value equivalent to a difference between a Euclidean distance between the second target signal waveform and the reproduced signal waveform and a Euclidean distance between the first target signal waveform and the reproduced signal waveform, and generating a second value equivalent to a difference between the Euclidean distance between the third target signal waveform and the reproduced signal waveform and the Euclidean distance between the first target signal waveform and the reproduced signal waveform; a step of calculating a shift evaluation value for evaluating the shift of the interested edge by using a difference between the first and second values; and a step of adjusting the recording condition by using the shift evaluation value for evaluating the shift of the interested edge.