Recording medium having a recorded phase reference signal for fine adjustment of a phase sampling clock signal

Claim 1

In a recording medium wherein positions of a leading edge and a trailing edge of each of pits formed at predetermined periods are shifted to individually selected ones of predetermined stepwise positions from a respective reference position in accordance with recording data to record the recording data on said recording medium, and the thus recorded data are read by sampling a reproduction signal reproduced from said recording medium in synchronism with a sampling clock signal, the improvement wherein first areas in which the recording data are recorded and second areas in which a reference signal for reading the recording data recorded in the first areas is recorded are formed periodically thereon, and the reference signal includes a phase reference signal which serves as a reference for fine adjustment of phase of the sampling clock signal, wherein the phase reference signal includes a signal of a first pattern constituted from positions of three successive first, second and third edges, and a signal of a second pattern constituted from positions of successive three other fourth, fifth and sixth edges and complementary to the first pattern.