Patent ID: 6538965
Filing Date: 2003-03-25
Classification: G11B

Abstract:
An optical disc having an information recording portion, the information recording portion having a spiral of a groove, the information recording portion having land portions located between portions of the groove which neighbor each other as viewed in a disc radial direction, wherein auxiliary information used when an information signal is recorded on and reproduced from the groove is previously recorded on the land portions, wherein the auxiliary information is represented by pre-pits provided in the land portions, wherein the information recording portion is divided into a plurality of zones as viewed in the disc radial direction, wherein in each of the zones, at least one of two sides of the groove wobbles at a fixed frequency in accordance with a constant angular velocity system, and wherein in each of the zones, phases of wobbles of respective neighboring portions of the groove are equal to each other, and the neighboring portions of the groove neighbor each other as viewed in the disc radial direction.