Adjusting method for recording condition and optical disc device

An adjusting method for a recording condition for an optical disc medium in which data are recorded by using codes whose shortest run length is 2T and from which the recorded data are reproduced in accordance with an adaptive equalizing procedure and a Partial Response Maximum Likelihood (PRML) procedure, comprising

• generating a first binary bit array by binarizing a signal reproduced from the optical disc medium in accordance with the PRML procedure;
• generating a second binary bit array and a third binary bit array whose shortest run length is equal to or greater than 2T, and which are obtained by shifting an interested edge of the first binary bit array to the left and right, respectively;
• generating first, second and third target signals corresponding to the first, second and third binary bit arrays, respectively;
• calculating a first evaluation value by normalizing a first Euclidean distance difference which is a difference between the Euclidean distance between the second target signal and the reproduced signal and the Euclidean distance between the first target signal and the reproduced signal, by the Euclidean distance between the first and the second target signals;
• calculating a second evaluation value by normalizing a second Euclidean distance difference which is a difference between the Euclidean distance between the third target signal and the reproduced signal and the Euclidean distance between the first target signal and the reproduced signal, by the Euclidean distance between the first and the third target signals;
• calculating an edge shift evaluation value by using at least a value of difference between the first and the second evaluation values;
• and
• adjusting the recording condition by using the edge shift evaluation value;
• wherein the second and the third bit array are generated by applying an exclusive OR (XOR) mask bit array to the first binary bit array so that a first Hamming distance between the first binary bit array and the second bit array is equal to a second Hamming distance between the first binary bit array and the third bit array, the first and second Hamming distance being greater than or equal to 2.

A recording method for an optical disc medium in which data are recorded by using codes whose shortest run length is 2T and from which the recorded data are reproduced in accordance with an adaptive equalizing procedure and a Partial Response Maximum Likelihood (PRML) procedure, comprising

• generating a first binary bit array by binarizing a signal reproduced from the optical disc medium in accordance with the PRML procedure;
• generating a second binary bit array and a third binary bit array whose shortest run length is equal to or greater than 2T, and which are obtained by shifting an interested edge of the first binary bit array to the left and right, respectively;
• generating first, second and third target signals corresponding to the first, second and third binary bit arrays, respectively;
• calculating a first evaluation value by normalizing a first Euclidean distance difference which is a difference between the Euclidean distance between the second target signal and the reproduced signal and the Euclidean distance between the first target signal and the reproduced signal, by the Euclidean distance between the first and the second target signals;
• calculating a second evaluation value by normalizing a second Euclidean distance difference which is a difference between the Euclidean distance between the third target signal and the reproduced signal and the Euclidean distance between the first target signal and the reproduced signal, by the Euclidean distance between the first and the third target signals;
• calculating an edge shift evaluation value by using at least a value of difference between the first and the second evaluation values;
• and
• adjusting a condition for recording by using the edge shift evaluation value;
• wherein the second and the third bit array are generated by applying an exclusive OR (XOR) mask bit array to the first binary bit array so that a first Hamming distance between the first binary bit array and the second bit array is equal to a second Hamming distance between the first binary bit array and the third bit array, the first and second Hamming distance being greater than or equal to 2.

A reproducing method for reproducing information from an optical disc medium in accordance with an adaptive equalizing procedure and a Partial Response Maximum Likelihood (PRML) procedure, comprising;

• irradiating the optical disc medium with a laser beam;
• and
• reproducing the information on the optical disc medium in accordance with the adaptive equalizing procedure and the PRML procedure;
• wherein the information is recorded to the optical disc medium via operations including:
• generating a first binary bit array by binarizing a signal reproduced from the optical disc medium in accordance with the PRML procedure;
• generating a second binary bit array and a third binary bit array whose shortest run length is equal to or greater than 2T, and which are obtained by shifting an interested edge of the first binary bit array to the left and right, respectively;
• generating first, second and third target signals corresponding to the first, second and third binary bit arrays, respectively;
• calculating a first evaluation value, by normalizing a first Euclidean distance difference which is a difference between the Euclidean distance between the second target signal and the reproduced signal and the Euclidean distance between the first target signal and the reproduced signal, by the Euclidean distance between the first and the second target signals;
• calculating a second evaluation value by normalizing a second Euclidean distance difference which is a difference between the Euclidean distance between the third target signal and the reproduced signal and the Euclidean distance between the first target signal and the reproduced signal, by the Euclidean distance between the first and the third target signals;
• calculating an edge shift evaluation value by using at least a value of difference between the first and the second evaluation values;
• and
• adjusting a condition for recording by using the edge shift evaluation value;
• wherein the second and the third bit array are generated by applying an exclusive OR (XOR) mask bit array to the first binary bit array so that a first Hamming distance between the first binary bit array and the second bit array is equal to a second Hamming distance between the first binary bit array and the third bit array, the first and second Hamming distance being greater than or equal to 2.