Optical storage medium and apparatus and method of reproducing data therefrom using different laser power

A phase-change recording type optical storage medium having a recording layer for storing main data and reproduction management data that indicates a first data which is updated periodically, arrival of the updated first data at a second predetermined data indicating generation of the second laser beam, in reproduction of the main data, a first laser beam or a second laser beam being irradiated on the optical storage medium according to the reproduction management data, the first laser beam having a first laser power capable of carrying the main data without erasing when reflected from the optical storage medium and the second laser beam having a second laser power capable of erasing the main data while carrying the main data when reflected from the optical storage medium, the first laser beam having a first laser power raising a temperature of the recording layer but below a first temperature at which the recording layer is in an amorphous state, the second power for raising a temperature of the recording layer higher than the first temperature but below a second temperature that is higher than the first temperature and is a specific max temperature beyond which reproduction of the main data is impossible.

A phase-change recording type optical storage medium having a recording layer for storing main data and reproduction management data that indicates a first predetermined data, arrival of a second data which is updated periodically at the first predetermined data indicating generation of the second laser beam, in reproduction of the main data, a first laser beam or a second laser beam being irradiated on the optical storage medium according to the reproduction management data, the first laser beam having a first laser power capable of carrying the main data without erasing when reflected from the optical storage medium and the second laser beam having a second laser power capable of erasing the main data from the optical storage medium while carrying the main data when reflected from the optical storage medium, the first laser beam having a first laser power raising a temperature of the recording layer but below a first temperature at which the recording layer is in an amorphous state, the second power for raising a temperature of the recording layer higher than the first temperature but below a second temperature that is higher than the first temperature and is a specific max temperature beyond which reproduction of the main data is impossible.

A phase-change recording type optical storage medium having a recording layer for storing main data and reproduction management data that indicates a first identification data, disagreement of the first identification data with a second entered identification data indicating generation of the second laser beam, in reproduction of the main data, a first laser beam or a second laser beam being irradiated on the optical storage medium according to the reproduction management data, the first laser beam having a first laser power capable of carrying the main data without erasing when reflected from the optical storage medium and the second laser beam having a second laser power capable of erasing the main data from the optical storage medium while carrying the main data when reflected from the optical storage medium, the first laser beam having a first laser power raising a temperature of the recording layer but below a first temperature at which the recording layer is in an amorphous state, the second power for raising a temperature of the recording layer higher than the first temperature but below a second temperature that is higher than the first temperature and is a specific max temperature beyond which reproduction of the main data is impossible.