Patent ID: 7400561

Claim:
A method for demodulating pre-formatted information embedded in an optical recording medium, said method comprising: receiving a wobble signal, the wobble signal represents data symbols which are frequency-modulated on a carrier frequency of a pre-formatted pattern of the recording medium; generating a phase delta signal representing a phase difference between the wobble signal and a corresponding locked signal having the carrier frequency; first sampling the phase delta signal at a data sampling interval so as to produce first values of the phase delta signal; second sampling the phase delta signal at each halfway of the data sampling interval so as to generate second values of the phase delta signal; determining, based on a difference between two successive second values, if said first sampling is performed at timing corresponding to an end of each data symbol; and adjusting sampling timing of said first sampling towards the timing corresponding to the end of each data symbol, if the sampling timing does not corresponds to the end of each data symbol.