Patent ID: 7376056

Claim:
A method for controlling read out of address information from an optical disc medium, the optical disc medium including a wobbled track groove on which a sine wave wobbled region, a first region and a second region are present and on which the same address information is recorded on the first and second regions, the first region including a plurality of sine wave wobbled portions, at least one of which has a phase inverted to that of the other portions, the second region including a plurality of wobbled portions that are steeply displaced either toward or away from the center of the optical disc medium with respect to a direction in which a laser beam scans the wobbled track groove, the method comprising: a) obtaining a first address signal and a second address signal which represent groove shapes of the first and second regions from a reflected light which is obtained by having the laser beam scan along the wobbled track groove; b) multiplying a first reference signal and the first address signal together to obtain a first multiplied signal, the first reference signal being phase-locked to, and having the same frequency as, a sine wave; c) multiplying a second reference signal and the second address signal together to obtain a second multiplied signal, the second reference signal being phase-locked to a sine wave and having a frequency that is an even number of times as high as that of a sine wave; d) integrating the first multiplied signal and the second multiplied signal separately to obtain a first integral and a second integral, respectively; and e) adding the first and second integrals together to obtain a sum and thereby detecting the address information based on the sum.