OPTICAL DISC AND OPTICAL DISC APPARATUS

摘要

An optical disc includes a SPOKE potion for detecting a position in a circumferential direction of the optical disc, which is formed on an inner or outer circumferential side relative to a data recording area and visible image drawing area. A signal portion in which each signal is constituted by a pair of light nonreflecting portion and light reflecting portion is formed in the SPOKE portion. The signal portion includes a first signal portion in which signal widths of the nonreflecting portion and reflecting portion are the same and a second signal portion in which the signal widths of the nonreflecting portion and reflecting portion are changed.