Optical disk drive and optical disk having a continuous information track formed of alternating land and groove revolutions

摘要

In an optical disk device using an optical disk of a single land/groove spiral configuration, headers dividing each track revolution into sectors have one or more mirror surface parts, and the disposition and/or length of the mirror surface parts is different between sectors at a connecting point and sectors which are not at a connecting point. The device includes a circuit for detecting a connecting point based on the position and/or length of the mirror surface part. The device is further provided with a circuit for predicting the connecting point, thereby making up for any failure of detection by the detecting circuit. Such a predicting circuit may have a circuit for predicting the connecting point based on the phase of the disk motor when a connecting point is previously detected, or alternatively a circuit for predicting the connecting point by counting the number of PLL clocks, from a sector preceding the sector which is at a connecting point.