Pit phase compensating method for sample servo optical disk drive

A novel recording-reproducing method has been developed to eliminate the phase deviation of reproduced data signals from magnetooptical (MO) pits from the demodulation clock for sampled-servo-format rewritable optical disk drives. The magnitude of the phase shift was found by simulation and confirmed by experiments. The phase error required to keep demodulation error rate below a specific value was also found. The method consists of writing extra MO domains in the leading segment of a sector to be recorded before data are recorded. The domains are reproduced to determine the adequate amount of phase compensation when data are read. An evaluation of the proposed recording-reproducing method showed that the pit phase compensation method is effective for use in MO disk drives