| 摘要 |
<P>PROBLEM TO BE SOLVED: To prevent pirated media from being produced by peeling by recording data needed for reproduction to a reflecting film. <P>SOLUTION: A pit which normally has a length 11T is divided into two pits P4 (4T) and P5 (4T) and a land L1 with a length 3T between them. Then the hatched land L1 between the two pits P4 and P5 is irradiated with a laser beam for additional recording. Consequently, the reflection factor of the land L1 decreases and after recording, the two pits are combined into one pit P7 when reproduced. The pit P7 has a length 11T and patterns (11T, 11T, 2T) of an original frame sink are formed after additional recording. An uneven pattern formed on a disk substrate after the reflecting film is peeled off does not constitute a regular frame sink, so a pirate media can not be manufactured by using this substrate. <P>COPYRIGHT: (C)2003,JPO |
