Patent ID: 7158462
Filing Date: 2007-01-02
Classification: G11B

Abstract:
1. A reproduced signal evaluation method of evaluating a reproduced signal reproduced from an information recording medium in which information composed of a plurality of codes differing in length is recorded, the reproduced signal evaluation method comprising evaluating the reproduced signal on the basis of the reproduced signal of the next shortest code after the shortest code reproduced from the information recording medium, wherein if the maximum value of the reproduced signal of the shortest code reproduced from the information recording medium is IaH and the minimum value of the reproduced signal is IaL, the maximum value of the reproduced signal of the next shortest code after the shortest code reproduced from the information recording medium is IbH and the minimum value of the reproduced signal is IbL, and the amplitude of the reproduced signal of the longest code or a code three times or more as long as the shortest code reproduced from the information recording medium is Ic, the reproduced signal is evaluated on the basis of the following expression: