Reproduction signal evaluation method

A reproduction signal evaluation method comprising:

• the first step of playing an information recording medium on which digital information is recorded by using optical means, and obtaining a reproduction signal reflecting the digital information;
• the second step of obtaining a multilevel equalization signal by equalizing the reproduction signal on the basis of a predetermined partial response characteristic;
• the third step of obtaining an amplitude level distribution of the equalization signal, and obtaining a plurality of actually measured peak values from the level distribution;
• the fourth step of obtaining a plurality of ideal peak values from the predetermined partial response characteristic;
• the fifth step of obtaining differences between the respective actually measured peak values and the corresponding ideal peak values;
• the sixth step of obtaining an evaluation value on the basis of the differences;
• and
• the seventh step of evaluating a characteristic of the reproduction signal on the basis of the evaluation value.

An information recording medium on which digital information is recorded such that a reproduction signal satisfying a predetermined evaluation condition is obtained when the reproduction signal is evaluated by a reproduction signal evaluation method comprising:

• the first step of playing an information recording medium on which digital information is recorded with record marks having various sizes by using optical means, and obtaining a reproduction signal reflecting the digital information;
• the second step of obtaining a first reproduction signal, of signals contained in the reproduction signal, which reflects digital information recorded with a record mark having a largest size;
• the third step of obtaining a second reproduction signal, of signals contained in the reproduction signal, which reflects digital information recorded with a record mark having a predetermined size other than a record mark having a smallest size;
• the fourth step of obtaining an evaluation value on the basis of the first and second reproduction signals;
• and
• the fifth step of evaluating a characteristic of the reproduction signal on the basis of the evaluation value.

An information reproduction apparatus for reproducing a reproduction signal satisfying a predetermined evaluation reference from an information recording medium on which digital information is recorded such that a reproduction signal satisfying a predetermined evaluation condition is obtained when the reproduction signal is evaluated by a reproduction signal evaluation method comprising:

• the first step of playing an information recording medium on which digital information is recorded with record marks having various sizes by using optical means, and obtaining a reproduction signal reflecting the digital information;
• the second step of obtaining a first reproduction signal, of signals contained in the reproduction signal, which reflects digital information recorded with a record mark having a largest size;
• the third step of obtaining a second reproduction signal, of signals contained in the reproduction signal, which reflects digital information recorded with a record mark having a predetermined size other than a record mark having a smallest size;
• the fourth step of obtaining an evaluation value on the basis of the first and second reproduction signals;
• and
• the fifth step of evaluating a characteristic of the reproduction signal on the basis of the evaluation value.