| 摘要 |
PROBLEM TO BE SOLVED: To prevent an illegal copy by satisfactorily discriminating it by taking an advantage of a physical means. SOLUTION: Main data SM are outputted to a posterior processing system as stream data through an external I/F 38. Sub-code data SSB are outputted to a control-use microprocessor, etc., via an external sub-code register 40. Discrimination data SIV recorded in a margin part 30 are not outputted outside, however, a leakage component by the discrimination data SIV is detected as a constant frequency component in the tracking error signal. However, since the discrimination data SIV do no exist in the illegal copy disk, such a leakage component element is not detected. Therefore, it is discriminate whether it is a regular disk or an illegal copy disk, by the presence or absence of a leakage component of a specific frequency in the tracking error signal. |
