MAGNETO-OPTICAL DISK AND MAGNETO-OPTICAL DISK DEVICE

PURPOSE:To enable recording and reproducing of data while preventing out of phase at the time of reproduction even among magneto-optical disk devices varying in manufacturers by providing ruggedness of 1 byte before a VFO3 part in a recording region, thereby lowering reflectivity before the VFO3 part. CONSTITUTION:The ruggedness 27 for lowering the reflectivity by 1 byte is provided by injection molding of polycarbonate from a master disk on the rear side of a GAP part B for controlling the output of a semiconductor laser at the time of data recording with the magneto-optical disk of 90mm. The reflectivity is lowered on the front side of the VFO3 part by such ruggedness 27, by which the magneto-optical disk having no marks is obtd. The out of phase at the time of reproduction is prevented even among the magneto-optical devices varying in the manufacturers.