Optical disc recording apparatus, optical disc recording methods, and optical discs

摘要

In apparatus for recording on a compact disc (1), sub-data strings are recorded so that the main data strings are reproducible by an optical pickup (13) for reproducing the main data strings, and the main data strings are protected from being copied illegally without any adverse effect on reproduction of the pit-and-land main data strings. The sub-data string (ED) is recorded by locally changing the reflectance of the reflection film in the form of irregularities such as pits or marks at a timing which does not affect the position information of the edge.