Patent ID: 9401172
Filing Date: 2016-07-26
CPC Classification: G11B

Claim Text:
1. An optical disc medium comprising a land and a groove at which information can be recorded, wherein address information unit which records address information of the land or groove is provided in each of plural regions into which a whole recording area of the optical disc medium is segmented at a predetermined angle in a circumferential direction and in a radial direction, wobbles are formed on the land and the groove, the address information unit includes the specific mark includes a wobble having a frequency about 1.5 times a frequency of a base wobble having waveform of a predetermined frequency, a wobble having a phase different from a phase of the base wobble by about 180 degree, and a wobble having a frequency about 1.5 times a frequency of the base wobble and having a phase different from a phase of the base wobble by about 180 degree, the address information wobble includes a wobble having a frequency about 1.25 times a frequency of the base wobble, a wobble having a frequency about 0.75 times a frequency of the base wobble, and a wobble having a phase different from a phase of the base wobble by about −90 or +90 degree, the address information wobble is disposed on either one of the plural predetermined fixed positions which is different from a position of another address information wobble adjacent to the address information wobble in a radial direction, the address information of land or groove in the optical disc medium is identified by difference in phase of the address information wobble.