Patent ID: 8045445
Filing Date: 2011-10-25
Classification: G11B

Abstract:
1. A method of manufacturing an information recording medium, the information recording medium having a predetermined code indicating whether tracking servo control is to be executed for a groove track or a land track, and at least a first recording layer and a second recording layer, the first recording layer including a groove track and a land track and the second recording layer including a groove track and a land track, information only to be recorded on one of the groove track and the land track of each of the first and second recording layers, the track on which the information is to be recorded having a wobbled portion, the groove track of each of the first and second recording layers being a convex portion of an asperity respectively formed on each of the first and second recording layers, and the land track of each of the first and second recording layers being a concave portion of the asperity respectively formed on each of the first and second recording layers, wherein the wobbled portion includes a waveform signal having a first signal portion including a first signal with a fundamental frequency, a second signal portion including a second signal that is the first signal modified by adding or subtracting a different signal that is different from the first signal, and a third signal portion including a third signal that has a frequency that is different from the fundamental frequency, and wherein the method of manufacturing the information recording medium comprises: selecting a configuration of a leading portion of a wobble pattern to be formed in the first recording layer so that the leading portion of the wobble pattern of the land track, in a case where information is recorded on the land track, is different from the leading portion of the wobble pattern of the groove track, in a case where information is recorded on the groove track, by 180 degrees in phase; forming the wobbled portion in the first recording layer in accordance with the selecting of the configuration of the leading portion of the wobble pattern in the first recording layer; selecting a configuration of a leading portion of a wobble pattern to be formed in the second recording layer so that the leading portion of the wobble pattern of the land track, in a case where information is recorded on the land track, is different from the leading portion of the wobble pattern of the groove track, in a case where information is recorded on the groove track, by 180 degrees in phase; forming the wobbled portion in the second recording layer in accordance with the selecting of the configuration of the leading portion of the wobble pattern in the second recording layer; and forming in the information recording medium, the predetermined code indicating whether tracking servo control is to be executed for a groove track or a land track.