Patent ID: 7315497

Claim:
A method for reproducing information from an information recording medium, wherein the information recording medium includes a reference wobble block which has a first wobble pattern representing a first information content, and an information wobble block which follows the reference wobble block and which has at least one of the first wobble pattern and a second wobble pattern representing a second information, wherein the first wobble pattern is represented by at least a first fundamental and a second harmonic of a Fourier series, and the second wobble pattern is represented by a first fundamental and a second harmonic of the Fourier series and the polarity of the second harmonic of the second wobble pattern is opposite the polarity of the second harmonic of the first wobble pattern, said method comprising: reading the reference wobble block; reading the information wobble block; comparing a second harmonic of a Fourier series of a wobble pattern read from the information wobble block with a second harmonic of a Fourier series of the first wobble pattern of the reference wobble block; judging that information recorded in the information wobble block is identical to the first information in a case that the phase of the second harmonic of the wobble pattern read from the information wobble block coincides with the phase of the second harmonic of the first wobble pattern, and judging that information recorded in the information wobble block is the second information in a case that the phase of the second harmonic of the wobble pattern read from the information wobble block is different from the phase of the second harmonic of the first wobble pattern; and outputting the first information in a case that the information recorded in the information wobble block is judged to be identical to the first information in said judging, and outputting the second information in a case that the information recorded in the information wobble block is judged to be different from the first information in said judging.