Optical data recording medium and method for reproducing recorded data

A rewriteable optical data recording medium, in which irradiation of a light beam is used for recording data and reproducing recorded data, and which includes a light-absorption layer made of phase change material on which the data is recorded, the rewriteable optical data recording medium comprising:

• a substrate on which a first groove for recording the data in the form of marks in said light-absorption layer and a second groove for recording address information corresponding to the data as marks in said light-absorption layer at the time of recording the data and indicative of a reproduction position of the data are provided;
• and
• a reproducing layer provided on a side of a light-incident surface of the substrate, the reproducing layer for reproduction of a signal from said marks which are shorter than a resolution limit of an optical system of a reproducing apparatus corresponding to the optical data recording medium.