Patent ID: 7054247
Filing Date: 2006-05-30
Classification: G11B,H04L

Abstract:
1. An information storage medium including a wobbled groove, wherein the wobbled groove wobbles in a radial direction, the wobbled groove has a wobble period which is based on multi-frequency shift keying corresponding to playback control information, the multi-frequency shift keying including 2-frequency shift keying, the playback control information contains address data, the playback control information has a one wobble-word length corresponding to a wobbled pattern change period of the wobbled groove, physical sector data recorded along the wobbled groove has a one-sync-frame length corresponding to the wobbled pattern change period, a one-physical-sector-data length corresponds to a one-address-data length the multi-frequency shift keying contains frequencies each of which satisfies orthogonal conditions, a minimum time slot interval within which each of the frequencies satisfies the orthogonal conditions is defined as Ts, a difference between a wobble signal obtained from the wobbled groove and a delayed wobble signal is integrated for a length of the wobbled pattern change period, the delayed wobble signal being obtained by delaying the wobble signal by Ts, a point of time when symbols indicating the playback control information are switched is detected by integrating the difference, and the symbols are derived from the wobble signal based on a detected point of time.