An optical information recording medium includes a substrate 1 and two
information layers (2, 4) formed on the substrate. The information layer
is formed of a thin film showing a change that can be detected optically by irradiation
of a light beam 7. A separating layer 3 that is transparent to a
wavelength of the light beam 7 is formed between the information layers
2 and 4. Each information layer (2, 4) includes a sector area
having sector address portions (9, 13) and data areas (8, 12) for
recording information signals, the sector address portion and the data area being
divided in the circumferential direction, and a management area (10, 14)
for recording identification information about the amount of dislocation between
the sector address portions 9 and 14 in the circumferential direction.
Thus, the identification information about the amount of dislocation can be recorded,
so that demodulation errors during reproduction can be reduced by switching amplification
gain or slice level during reproduction according to the identification information.
Also, stable data recording can be achieved by switching recording power according
to a gate signal.
