Patent ID: 7349304

Claim:
An information storage medium evaluation apparatus for evaluating an information storage medium, which comprises a wobbled track that is used to guide a light beam and is wobbled in correspondence with a frequency, a phase of which is modulated at predetermined timings to reflect predetermined information, comprising: a detection unit configured to detect reflected light of the light beam with which the wobbled track formed on the information storage medium is irradiated; a filter unit configured to suppress noise from a reproduction signal corresponding to the wobbled track on the basis of the reflected light detected by the detection unit; a squaring unit configured to square the reproduction signal from which the noise is suppressed by the filter unit; and an evaluation unit configured to evaluate a quality of the wobbled track on the basis of frequency characteristics of the squared reproduction signal squared by the squaring unit, wherein when the squaring unit squares a predetermined sine wave and outputs the squared sine wave, a peak level at a predetermined frequency obtained from frequency characteristics of the sine wave appears at a frequency twice the predetermined frequency in frequency characteristics of the squared sine wave, and the evaluation unit has characteristics that set a residual peak level corresponding to a residual level in the predetermined frequency obtained from the frequency characteristics of the squared sine wave to be lower by not less than 30 dB than a peak level that appears at the frequency twice the predetermined frequency.