| 摘要 |
<p>An optical disc (200) has a recording region divided into 28 zones from zone Z0 to Z27. Between adjacent tracks within a zone, the wave numbers of wobble are made identical. That is, the wave numbers of ADIP carrier are made identical. Thus, it is possible to match the inphase with the outphase in average, thereby reducing a WPP signal. Thus, it is possible to obtain an optical disc in which a low-frequency component is not superimposed on a push-pull signal even if the track pitch is smaller than 1.6 micrometers such as the next-generation MD (2) having the track pitch as small as 1.25 micrometers and even if a mark is to be detected from the groove by DWDD.</p> |
