FIELD: optical disk, having a record in form of a groove marked in advance.
SUBSTANCE: disk contains area for recording and reproduction and reproduction only area. In first data, representing user data, and in third data, identical error correction codes are used. First data contain structure of first error correction block, third data contain structure of second error correction block. Recording density of third data is selected to be less than recording density of first data, and number of correction codes in first error correction block is selected to be divisible by m, while amount of correction codes in second error correction block is set divisible by n/m of number of correction codes in first error correction block, so that count of data sections in second error correction block is also divisible by n/m of data portion counting value in first error correction block.
EFFECT: good information recording technique, concerning time of disk manufacturing with high recording density.
3 cl, 34 dwg
