Patent ID: 7394740

Claim:
A reproduction signal evaluation method comprising: a 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; a 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, on condition that the digital information is recorded by RLL (1, n) modulation; a 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, on condition that the digital information is recorded by the RLL (1, n) modulation; a fourth step of obtaining an evaluation value on the basis of the first and second reproduction signals; and a fifth step of evaluating a characteristic of the reproduction signal on the basis of the evaluation value.